description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 09/771,226, which was filed Jan. 26, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to stable concentrated non-aqueous suspensions of particles with excellent storage stability. More specifically, the particle suspensions are characterized by having a medium of low molecular weight polyalkylene glycol and a stabilizer of a hydrogenated castor wax.
[0004] 2. Description of the Related Art
[0005] Heretofore, in preparing aqueous dilutions of particles, it has been necessary to utilize solid ingredients that are mixed with water or other aqueous fluid at the job site. A number of disadvantages are inherent in such mixing procedures, particularly when large volumes of solutions are prepared. For example, special mixing equipment for mixing the dry additives with water is required and problems such as chemical dusting, uneven mixing, and extended preparation and mixing time are involved. In addition, the mixing and physical handling of large quantities of dry chemicals require a great deal of manpower, and, where continuous mixing is required, the accurate and efficient handling of chemicals is extremely difficult.
[0006] In addition, when particles are used, they are typically added to water to make a dilute solution, resulting in the generation of fugitive dust. This dust has a number of potential detrimental effects. Workers preparing the solution can inhale the dust, and some of the particles that can be suspended in a non-toxic solvent produce dust when handled in a powdered form. This may produce a respiratory allergenic response, irritation, or other toxic effect when inhaled. Dust can also drift to areas where it is not intended.
[0007] In the agricultural industry, many handling problems may arise when one is forced to prepare aqueous end-use formulations and/or slurries from solids, especially active solids, e.g. wettable bioactive powders. Farmers preparing tank mixes of herbicides, insecticides and/or other bioactives from solids for applications to crops and soil are exposed to certain safety hazards and inconveniences due to the generation of noxious dusts which may be irritable to the skin and hazardous to breathe.
[0008] Additionally, finely ground powders, even so-called powders, of many water-soluble bioactives do not disperse well when prepared as tank mixes. They have poor spontaneity or “bloom” and have low suspendability. They have poor re-dispersibility and are incompatible with other bioactives as compared to liquid bioactive concentrates. Thus, final formulators, such as farmers, when preparing diluted aqueous active compositions find that the handling and application of solids materials, such as fertilizers, are much easier if the material can be supplied in a fluid rather than solid form. Economics then dictate that the active material be supplied in a highly concentrated fluid to the final formulator.
[0009] Saturation solubility in water of many water-soluble active constituents, such as potassium chloride, is too low to make it economical for supply to the end-user simply in the form of a solution. Alternatively, highly concentrated suspensions of water-soluble compounds, both in water and in organic liquids, have very poor storage, freeze/thaw, and heat/cool stability. As a result of the spontaneous crystal dissolution-recrystallization process, there occurs a progressive increase in the size of the particulate active material. This increase in particle size results in settling, bleed and changes in visco-elastic properties and thus severely limits concentrate loading levels.
[0010] To avoid lump or dust formation and its associated problems, the particles can be added to the aqueous systems as liquid slurries or suspensions. There currently exists a number of methods for accomplishing this, and the compositions prepared thereby. These methods often employ use oil carriers (e.g., mineral, isopariffin or diesel) to suspend and deliver the particles to the aqueous systems. In applications where the materials may be used in off-shore oil well treatment fluids which may be eventually discharged into the environment, recent regulations by the Environmental Protection Agency limit the amount of oil or grease that can be used in offshore oilfield applications for well treatment fluids. The National Pollutant Discharge Elimination System (NPDES) General Permit issued on Apr. 19,1999 (Federal Register Vol. 64 No. 74) limits the oil and grease to a daily maximum concentration of 42 mg/l and a monthly average of 29 mg/l when the suspension is diluted to the intended use level with fresh or salt water. Unlike the liquid suspensions that contain diesel fuel or other hydrocarbon solvents the suspensions of the present invention contain minimal detectable oil or grease when diluted to the concentration appropriate for well treatment.
[0011] U.S. Pat. No. 5,091,448 discloses a suspending medium for a water-soluble polymer, while U.S. Pat. No. 5,631,313 discloses a suspending medium for particles. These two patents utilize isopariffin oils as the solvent for the suspensions where a styrene/isoprene copolymer is used as the suspension agent. Upon dilution to the intended use concentration in fresh or salt water for a well treatment fluid, the dilution contains a much higher concentration of oil and grease than is permitted by the above regulations. Furthermore the styrene/isoprene copolymer that is used to stabilize the suspension is insoluble in water miscible solvents such as the polyalkylene glycols of the present invention.
[0012] U.S. Pat. No. 5,925,182 discloses a stable liquid suspension composition including a liquid carrier, a solid fatty acid or a salt thereof, and a solid particulate wherein the liquid carrier is selected from the group consisting of oils, olefins, terpenes, glycols, esters, ethers, alcohols, and combinations of any two or more thereof and the liquid carrier, solid fatty acid or salt thereof, and solid particulate are each present in the composition in a stabilizing amount sufficient to produce a stable liquid suspension. Also disclosed is a stable liquid composition including a liquid carrier, an oil soluble polymer, and a solid particulate wherein the liquid carrier is selected from the group consisting of olefins, terpenes, esters, and combinations of any two or more thereof and the liquid carrier, oil-soluble polymer, and solid particulate are each present in the composition in a stabilizing amount sufficient to effect the formation of a stable liquid suspension. Although this patent includes some solvents that may be environmentally friendly and some that contribute to oil and grease as measured by the EPA method, the suspension agent is based on a fatty acid or salt thereof, or an oil soluble polymer, either of which will be measured as oil and grease.
[0013] In addition to the oil carrier fluid, many hydrocarbon solvent based slurries usually contain clay or clay like particulates that act to viscosify and stabilize the non-aqueous suspension. The clay component itself is also often times an undesirable component. This is particularly true in oil and gas field applications where incorporation of the clay into the slurries, which is necessary to keep the particles in suspension, impairs the permeability of the oil or gas bearing strata. This is the very same problem caused by the formation of lumps that the oil suspension or slurry is supposed to eliminate.
[0014] Many aqueous suspensions include a variety of inorganic and organic particles that use water as the continuous phase for preparing the liquid solution or suspension. While the use of water is certainly environmentally acceptable and reduces the dusting properties of many solid particles, its use is counterproductive with many solids. Among these are solids that may be reactive with water. Also, particles may be wholly or partially soluble in water and this solubility may limit the maximum concentration of the dispersed phase that can be incorporated into an aqueous suspension. The use of a non-solvent for suspending certain solids results in a controlled release of the solids because the particles must first dissolve into water before they become functional.
[0015] U.S. Pat. No. 4,673,526 discloses an anhydrous skin cleansing composition containing an oil phase, an emulsifying agent, and particulate water soluble polymeric abrasive particles. This compound contains an oily phase, at least one emulsifying agent, and at least one abrasive substance. The compound is presented in anhydrous form and the abrasive substance in suspension in the oily phase is highly hydrosoluble with an average particle size between 50 and 1000 microns. This compound allows the deep cleansing of the skin through exfoliant action.
[0016] U.S. Pat. No. 5,985,252 discloses a suspension antiperspirant composition for topical application to the human skin including from 10 to 26% by weight of the composition of a solid particulate antiperspirant active suspended in a cosmetic base. The antiperspirant active includes a blend of an antiperspirant active with relatively small particles with a volume average particle size in the range of from 0.5 to 8 micrometers and an antiperspirant active with relatively large particles having a volume average particle size in the range of larger than 12 to smaller than 50 micrometers with the weight ratio of the antiperspirant active having smaller particles to the antiperspirant active having larger particles in the composition is in the region of 5:1 to 1:5 by weight.
[0017] U.S. Pat. No. 5,863,647 discloses a monodisperse glycol suspension having excellent dispersion stability at a pH within a wide range. The suspension includes a monodisperse suspension in a glycol of spherical fine particles of an amorphous inorganic oxide having an average particle diameter of 0.15 to 5 micrometers and a relative particle size standard deviation of 1.0 to 1.5 and containing glycol bonded to its surface in amounts of 0.003 to 5 millimoles glycol, per gram of fine particles. This monodisperse suspension is useful as a raw material for the production of a polyester film having improved slipperiness.
[0018] Despite the above teachings, there still exists a need for liquid suspensions for water-soluble polymers that are environmentally friendly; suitable for use in personal care products, such as cosmetics and shampoos and the like; can be manufactured using ingredients suitable for use in indirect contact with food or as a pesticide adjuvant; are extremely stable over long periods of time and are operative over a wide temperature range; and are comprised of materials that are commercially available or easy to manufacture.
SUMMARY OF THE INVENTION
[0019] In accordance with the present invention, a non-aqueous suspension includes solid particles, polyalkylene glycol, and a suspension stabilizer of a hydrogenated castor oil or wax. The non-aqueous suspension includes the solid particles in an amount between about 0.1 and about 75 percent by weight of the suspension, the polyalkylene glycol in an amount between about 24 and about 99.8 percent by weight of the suspension, and the suspension stabilizer in an amount between about 0.1 and about 5.0 percent by weight of the suspension. The non-aqueous suspension may further include one or more of the following additive materials: proppants, antifoaming agents, surfactants, corrosion inhibitors, pH buffers, and preservatives.
[0020] The polyalkylene glycol includes polyethylene glycol, polypropylene glycol, ethylene oxide propylene oxide block copolymers, and mixtures thereof. The polyalkylene glycol may include between about 0.1 and 4% by weight of the polyalkylene glycol of a thickener including partially neutralized polyacrylic acid, hydroxypropyl cellulose, highly substituted hydroxypropyl guar, fumed silica, hydrophobic silica, and mixtures thereof.
[0021] The solid particles include non-polymeric particles that are either inorganic particles or organic particles. The inorganic particles include boron compounds; alkaline earth peroxides; magnesium peroxide or calcium peroxide; iron oxide; calcium aluminate, calcium carbonate, magnesium carbonate, calcium oxide, magnesium oxide, calcium hydroxide and magnesium hydroxide and mixtures thereof; and siliceous or ceramic particles. The organic particles include gilsonite; lignosulfonates and the sodium, potassium, ammonium, calcium and magnesium salts thereof; and ethylenediaminetetraacetic acid and the salts thereof. The particles further include fertilizers selected from the group consisting of potassium nitrate, ammonium dihydrogenphosphate, ammonium nitrate, sodium nitrate ammonium phosphate, ammonium polyphosphate, potassium hydrogen phosphate, disodium hydrogen phosphate, urea, and mixtures thereof. The particles still further include pesticides selected from the group consisting of boric acid, butocarboxime, acephate, dimethoate, dimehypo, vamidothion, methomyl and mixtures thereof. The particles even further include herbicides selected from the group consisting of dalapon (2,2 dichloropropirionic acid, sodium salt) ammonium sulfamate, dicamba, cacodylic acid, fomesafen; glyphosate and mixtures thereof. The particles yet further include fingicides selected from the group consisting of copper sulfate, fosetyl-Al aluminum tris (O-ethyl phosphonate), benalaxyl, guazatine, kasugamycin and mixtures thereof.
[0022] In a method of formulating a non-aqueous suspension, solid particles from about 0.1 to about 75% suspension weight and a hydrogenated castor wax or oil from about 0.1 to about 5.0% suspension weight are dispersed into from about 24 to about 99.8% suspension weight of polyalkylene glycol. The solid particles, hydrogenated castor wax, and polyalkylene glycol are mixed until the solid particles are uniformly dispersed in the polyalkylene glycol and the hydrogenated castor wax has developed desired suspension properties.
[0023] It is therefore an object of the present invention to provide non-aqueous suspensions that are environmentally friendly.
[0024] It is another object of the present invention to provide non-aqueous suspensions suitable for use in personal care products, such as cosmetics, shampoos, and the like.
[0025] It is still another object of the present invention to provide non-aqueous suspensions that can be manufactured using ingredients suitable for use in indirect contact with food or as a pesticide adjuvant.
[0026] It is a further object of the present invention to provide non-aqueous suspensions that are extremely stable over long periods of time and that are operative over a wide temperature range.
[0027] It is still a further object of the present invention to provide non-aqueous suspensions that are comprised of materials that are commercially available or easy to manufacture.
[0028] Still other objects, features, and advantages of the present invention will become evident to those of ordinary skill in the art in light of the following.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] A first element of a liquid particle suspension includes solid particles in an amount from 0.1 to 75% of the weight of the suspension. The particles are typically non-polymeric and may be inorganic or organic. Typically the particles of interest will have one or more or the following characteristics that favor use in a concentrated non-aqueous dispersion: 1) low water solubility or materials with high water solubility that have a tendency to have very poor storage, freeze/thaw, and heat/cool stability; 2) the need for a controlled dissolution rate; 3) materials that are reactive with water or a water hydratable agent; 4) materials that cause nuisance dusts; and 5) materials that are easier to meter in liquid form rather than by weighing and pre-dissolving in water when needed at a job site. Typically the particles will have an average particle size between 0.1 micron and 500 microns. More preferably, the particles will have an average particle size between 1 micron and 300 microns. Most preferably the particles will have an average particle size between 5 microns and 200 microns.
[0030] Solid particles include a wide variety of materials including inorganic as well as organic solid particles. Illustrative examples of specific solid particles include but are not limited to: peroxides such as magnesium peroxide and calcium peroxide, magnesium oxide, calcium oxide, herbicides including butocarboxime, acephate, dimethoate, dimehypo, vamidothion, methomyl, dalapon (2,2 dichloropropirionic acid, sodium salt) ammonium sulfamate, dicamba, cacodylic acid, fomesafen; glyphosate, copper sulfate, fosetyl-Al aluminum tris (O-ethyl phosphonate), benalaxyl, guazatine, kasugamycin; insecticides, sulfonated asphalt, salts of sulfonated asphalt, lime, sodium bicarbonate, sodium carbonate, sodium borate, boric acid, potassium nitrate, ammonium dihydrophosphate, ammonium nitrate, sodium nitrate ammonium phosphate, ammonium polyphosphate, potassium hydrogen phosphate, disodium hydrogen phosphate, urea, molybdenum disulfide, pigments, activated carbon, carbon black, unintahite (gilsonite), graphite, iron, iron oxide, zinc, tin, quebracho, lignin, lignite, caustisized lignite, lignosulfonate, chrome lignosulfonate, naphthalenesulfonate; and, combinations of two or more thereof.
[0031] A second element of the suspension includes polyalkylene glycol or thickened polyalkylene glycol. The amount of this ingredient varies between about 24 to 99.8% of the weight of the suspension. Particularly preferred are polyethylene glycol, polypropylene glycol or ethylene oxide propylene oxide block copolymers. Most preferred is low molecular weight glycols having a molecular weight of less than 1000, more preferably having a molecular weight between 100 and 600 and most preferably between 200 and 500. Polyethylene glycol having a molecular weight of 200 can also be used, for example. Polyethylene or polypropylene glycol having a molecular weight of 300 or higher and manufactured in accordance with the specifications of the National Formulary can be used in cosmetic grade applications. A technical grade of polyethylene or polypropylene glycol having a molecular weight of 300 or higher as indirect additives for food contact materials and the like may also be used. Technical grades of polyethylene glycol with a molecular weight of 300 or higher are exempt from residue tolerance when used as inert ingredients in pesticide formulations employed in growing crops.
[0032] The term “thickened polyalkylene glycol” refers to polyalkylene glycols having a thickener preferably between 0.1 and 4% by weight of the polyalkylene glycol selected from the group consisting of partially neutralized polyacrylic acid, hydroxypropyl cellulose, highly substituted hydroxypropyl guar, hydrated thickening silica including fumed silica and hydrophobic fumed silica, or their functional equivalents or mixtures thereof. The preferred hydrated thickening silicas, also known as thickening silicas, are colloidal gel silicas or hydrophobic derivatives thereof. More preferred ones are Aerosil®200 silica, available from Degussa Corporation, Ridgefield Park N.J., and CAB-O-SIL®M-5 and TS-530 available from Cabot Corporation, Tuscola, Ill. The most preferred is CAB-O-SIL® TS-530.
[0033] A third element of the suspension includes a finely divided hydrogenated oil or wax. Most preferably this hydrogenated oil or wax is hydrogenated castor wax. This material is present in the amount from 0.1 to 5% of the weight of the suspension. More preferably in the amount of 0.3 to 3% of the weight of the suspension. Most preferably in the amount of 0.5 to 2% of the weight of the suspension. The preferred hydrogenated castor wax is sold by Süd Chemie of Louisville, Ky. under the name of Rheocin®. Rheocin® is acceptable for use as an indirect food additive in Title 21 of the Code of Federal Regulations.
[0034] In addition to the foregoing three elements, the suspension may also contain optional ingredients such as: antifoaming agents, corrosion inhibitors, preservatives, surfactants, water miscible co-solvents, and other materials that aid in the performance of the solid particles in their intended applications.
[0035] The suspensions may be used in any number of commercial applications where dry solid particles have previously been used, as well as in applications where solid particles have not been well suited due to their undesirable physical properties, such as low water solubility, stability in concentrated aqueous solutions, the need for a controlled dissolution rate, materials that are reactive with water or a water hydratable suspension agent, materials that cause nuisance dusts, and materials that are easier to meter in liquid form rather than by weighing and pre-dissolving in water when needed at a job site.
[0036] The suspensions are particularly useful for applications involving dispersing solid particles in aqueous solutions. Included among such applications are the following: environmental applications (e.g., remediation projects), agricultural applications metal working fluids, paper applications, textile applications, cosmetic or personal care applications, cleaners, detergents, application of pesticides, aerial firefighting applications, construction products (e.g. paint, joint cements, texture finishing compounds and the like), emulsion stabilizers, adhesives, inks, and oil field applications.
EXAMPLES
Example 1
Inventive Suspension Media
[0037] A method for making the suspensions of solid particles includes dispersing from 0.1 to 75% suspension weight of a particle and from 0.1 to 5.0% suspension weight of a hydrogenated castor wax or oil into from 24 to 99% suspension weight of polyalkylene glycol. The solid particles, hydrogenated castor wax, and polyalkylene glycol are mixed using conventional agitation, such as an overhead mixer, until the solid particles are uniformly dispersed in the polyalkylene glycol and the hydrogenated castor wax has developed the desired suspension properties. Desirable properties of the suspension include but are not limited to the following:
[0038] 1. The solvent and suspension stabilizer are environmentally friendly and non-toxic;
[0039] 2. The particle suspension does not create dust upon addition to water;
[0040] 3. The suspension remains stable for extremely long periods of time exhibiting minimum separation of solvent and particulate and no packing of the solid particles;
[0041] 4. The suspension is easily pourable or pumpable;
[0042] 5. The suspended particles disperse in water better than if the solid is added to water;
Example 2
Sodium Tetraborate Inventive Suspension
[0043] 810 grams of a powdered anhydrous sodium tetraborate and 20 grams of Rheocine® are dispersed into 1160 grams of pre-thickened polyethylene glycol (200 MW) containing 10 grams thickening silica, specifically CAB-O-SIL® TS-530, in a 2000 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition (% by weight) Sodium tetraborate 40.50% Rheocin ® 1.0% Pre-thickened Polyethylene glycol 200 MW 58.4% Initial viscosity 4610 cP Density 1.365 g/ml Pounds of sodium tetraborate per U.S. Gallon 4.6 Properties upon aging Separation Packing 24 hours 0% None 3 days 0% None 1 month 1% None 3 months 4% None
[0044] The above composition is easily pourable or pumpable.
Example 3
Sodium Tetraborate Control Suspension
[0045] This example compares the suspension properties of anhydrous sodium tetraborate to Example 2 without the use of the hydrogenated castor wax. 810 grams of sodium tetraborate is dispersed into 1170 grams of polyethylene glycol (200 MW) in a 2000 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition (% by weight) Sodium tetraborate 40.50% Polyethylene glycol 200MW 59.50% Initial viscosity l250 cP Density 1.37 g/ml Pounds per Gallon of Borate Compound 4.6 Properties on aging Supernatant separation Particle packing 24 hours 12% by volume Medium packed Difficult to remix with stirring rod 3 days 22% by volume Hard packed can not remix with stirring rod 1 week 30% by volume Hard packed can not remix with stirring rod
Example 4
Magnesium Peroxide Inventive Suspension
[0046] 250 grams of a powdered Magnesium Peroxide and 5.0 grams of Rheocin® are dispersed into 240 grams pre-thickened polyethylene glycol (200 MW) containing 5 grams thickening silica, specifically CAB-O-SIL® TS-530a making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition Magnesium Peroxide 50% Rheocin ® 1% Pre-thickened Polyethylene glycol 200MW 49% Initial Viscosity 3200 cP Density 1.515 g/ml Pounds of magnesium peroxide per U.S. Gallon 6.3 Properties on aging Separation Packing 24 hours 0% None 3 days 0% None 1 month 1% None 3 months 2% None
[0047] The above compositions are easily pourable or pumpable
Example 5
Inventive Colemanite Suspension
[0048] Turkish Colemanite is an ore rich in calcium borate supplied by American Borate. 240 grams of a powdered Colemanite and 4.5 grams of Rheocin® are dispersed into 207.5 grams pre-thickened polyethylene glycol (200 MW) containing 4.5 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Colemanite 53.1% Rheocin ® 1% Pre-thickened Polyethylene glycol 200MW 45.9% Initial Viscosity 2700 cP Initial density 1.6 g/ml Pounds of Colemanite per U.S. gallon 7.1 Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 1% None 3 months 2% None
[0049] The above compositions are easily pourable or pumpable
Example 6
Colemanite Control Suspension
[0050] This example compares the suspension properties of Colemanite to example 5 without the use of the hydrogenated castor wax suspension agent. 240 grams of a powdered Colemanite and are dispersed into 212 grams pre-thickened polyethylene glycol (200 MW) containing 4.5 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Colemanite 53.1% Pre-thickened Polyethylene 46.9% glycol 200 MW Initial Viscosity 1100 cP Initial density 1.6 g/ml Pounds of Colmanite per 7.1 U.S. gallon Properties on aging Separation Packing 24 hours 2% None 7 days 22% Significant settling; difficult to remix 1 month 27% Hard packed sediment; very difficult to remix 3 months 29% Hard packed sediment; very difficult to remix
Example 7
Inventive Gilsonite Suspension
[0051] Gilsonite is an asphaltic material or solidified hydrocarbon used in a variety of applications in explosives, oil field and other industrial applications. Powdered gilsonite is available from American Gilsonite and others. 100 grams of a powdered gilsonite and 6 grams of Rheocin® are dispersed into 194 grams polyethylene glycol (200 MW) making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Powdered gilsonite 33.3% Rheocin ® 2% Polyethylene glycol 200 MW 64.7% Initial Viscosity 3300 cP Initial density 1.1 g/ml Pounds of gilsonite per U.S. gallon 3 Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 0% None 3 months 1% None
[0052] The above compositions are easily pourable or pumpable
Example 8
Control Gilsonite Suspension
[0053] This example compares the suspension properties of gilsonite to example 7 without the use of the hydrogenated castor wax suspension agent. 100 grams of a powdered gilsonite and are dispersed into 200 grams polyethylene glycol (200 MW) making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Powdered Gilsonite 33.3% Polyethylene glycol 200 MW 66.7% Initial Viscosity 360 cP Initial density 1.1 g/ml Pounds of Gilsonite per 7.1 U.S. gallon Properties on aging Separation Packing (Floating) 24 hours 19% Note: Due to the light density of the suspended phase (gilsonite) separation rose to the surface in this case (floated). At 24 hrs it was able to be remixed with some difficulty. 7 days 22% Significant floating; difficult to remix 1 month 33% The individual particles of gilsonite have coalesced into a continuous phase. This phase solid and can not be remixed without extreme measures. 3 months 35% The overall appearance is unchanged from 1 month. The coalesced upper phase has formed a tar like continuous phase which can not be remixed without extreme measures.
Example 9
Inventive Calcium Aluminate Suspension
[0054] Calcium aluminate is an alkaline pH buffer supplied by Sintertec Division of BPI, Inc. It has a low solubility in water, which makes it useful as a controlled release buffer that supplies alkalinity as acid enters a system. The low water solubility of calcium aluminate makes it difficult to supply as an aqueous dispersion of solution. 275 grams of a powdered calcium aluminate and 8 grams of Rheocin® are dispersed into 196 grams pre-thickened polyethylene glycol (200 MW) containing 4 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium aluminate 57.4% Rheocin ® 1.7% Pre-thickened Polyethylene 40.1% glycol 200 MW Initial Viscosity 4950 cP Initial density 1.9 g/ml Pounds of calcium aluminate per 9.1 U.S. gallon Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 1.5% None 3 months 3% None
[0055] The above compositions are easily pourable or pumpable
Example 10
Control Calcium Aluminate Suspension
[0056] This example compares the suspension properties of calcium aluminate to example 9 without the use of the hydrogenated castor wax suspension agent. 275 grams of a powdered calcium aluminate is dispersed into 196 grams pre-thickened polyethylene glycol (200 MW) containing 4 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium aluminate 57.4% Pre-thickened Polyethylene 42.6% glycol 200 MW Initial Viscosity 700 cP Initial density 1.85 g/ml Pounds of Calcium Aluminate 8.9 per U.S. gallon Properties on aging Separation Packing 24 hours 2% None 7 days 17% Significant settling; difficult to remix 1 month 23% Hard packed sediment; very difficult to remix
Example 11
Inventive Calcium Carbonate Suspension
[0057] Calcium carbonate is widely used in a number of industries as an extender pigment. It is also used in agricultural applications as a pH buffer to adjust the pH of acidic soils. It has a low solubility in water. The low water solubility of calcium carbonate makes it difficult to supply as an aqueous solution. 200 grams of a powdered calcium carbonate and 8 grams of Rheocin® are dispersed into 192 grams pre-thickened polyethylene glycol (200 MW) containing 4 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium carbonate 50% Rheocin ® 2% Pre-thickened Polyethylene 48% glycol 200 MW Initial Viscosity 2700 cP Initial density 1.57 g/ml Pounds of calcium carbonate 6.5 per U.S. gallon Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 2% None 3 months 3% None
[0058] The above compositions are easily pourable or pumpable
Example 12
Control Calcium Carbonate Suspension
[0059] This example compares the suspension properties of calcium carbonate to example 11 without the use of the hydrogenated castor wax suspension agent. 200 grams of a powdered calcium carbonate is dispersed into 200 grams pre-thickened polyethylene glycol (200 MW) containing 4 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium carbonate 50% Pre-thickened Polyethylene 50% glycol 200 MW Initial Viscosity 280 cP Initial density 1.58 g/ml Pounds of calcium carbonate 6.5 per U.S. gallon Properties on aging Separation Packing 24 hours 12% None 7 days 43% Hard packed sediment; very difficult to remix 1 month 45% Hard packed sediment; very difficult to remix 3 months 45% Hard packed sediment; very difficult to remix
Example 13
Inventive Iron Oxide Suspension
[0060] Iron (III) oxide (Fe 2 O 3 ) is used as a pigment, as a mordant, as a catalyst and on magnetic recording tapes. It is also used as a weighting agent in oil field applications. The low water solubility of Fe 2 O 3 makes it difficult to supply as an aqueous solution. 390 grams of a Iron (III) oxide which has an average particle size of 5 micrometers and 6 grams of Rheocin® are dispersed into 350 grams pre-thickened polyethylene glycol (200 MW) containing 6 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Fe 2 O 3 51.9% Rheocin ® 0.8% Pre-thickened Polyethylene 47.3% glycol 200 MW Initial Viscosity 6100 cP Initial density 1.8 g/ml Pounds of Fe 2 O 3 per U.S. gallon 7.8 Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 0% None 3 months 2% None
[0061] The above compositions are easily pourable or pumpable
Example 14
Control Iron Oxide Suspension
[0062] This example compares the suspension properties of Fe 2 O 3 to example 13 without the use of the hydrogenated castor wax suspension agent. 390 grams of a Fe 2 O 3 having an average particle size of 5 micrometers is dispersed into 356 grams pre-thickened polyethylene glycol (200 MW) containing 6 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Fe 2 O 3 51.9% Pre-thickened Polyethylene 48.1% glycol 200 MW Initial Viscosity 3000 cP Initial density 1.8 g/ml Pounds of Fe 2 O 3 per U.S. gallon 7.8 Properties on aging Separation Packing 24 hours <1% None 7 days <1% None 1 month 5% Slight packing, easy to remix 3 months 15% Moderate packing, fairly easy to remix
Example 15
Inventive Titanium Dioxide Suspension
[0063] Titanium dioxide (TiO 2 ) is used as a primary pigment in a variety of coating applications. The low water solubility of TiO 2 makes it difficult to supply as an aqueous solution. 250 grams of a TiO 2 which has been sifted through a 325 mesh screen and 5 grams of Rheocin® are dispersed into 370 grams pre-thickened polyethylene glycol (200 MW) containing 5 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight TiO 2 40% Rheocin ® 0.8% Pre-thickened Polyethylene 59.2% glycol 200 MW Initial Viscosity 4200 cP Initial density 1.57 g/ml Pounds of TiO 2 per U.S. gallon 5.2 Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 0% None 3 months <1% None
[0064] The above compositions are easily pourable or pumpable
Example 16
Control Titanium Dioxide Suspension
[0065] This example compares the suspension properties of TiO 2 to example 15 without the use of the hydrogenated castor wax suspension agent. 250 grams of a TiO 2 which had been sifted through a 325 mesh screen is dispersed into 370 grams pre-thickened polyethylene glycol (200 MW) containing 5 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight TiO 2 40% Pre-thickened Polyethylene 60% glycol 200 MW Initial Viscosity 2100 cP Initial density 1.57 g/ml Pounds of TiO 2 per U.S. gallon 5.2 Properties on aging Separation Packing 24 hours <1% None 7 days <1% None 1 month 7% Slight packing, fairly easy to remix 3 months 13% Moderate packing; fairly easy to remix
Example 17
Inventive Calcium Lignosulfonate Suspension
[0066] Calcium lignosulfonate is widely used in a number of industries, including oil well cements, as a dispersant. It has a low solubility in water. The low water solubility of calcium lignosulfonate makes it difficult to supply as an aqueous solution. 105 grams of a powdered calcium lignosulfonate and 3 grams of Rheocin® are dispersed into 192 grams pre-thickened polyethylene glycol (200 MW) containing 3 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium lignosulfonate 35% Rheocin ® 1% Pre-thickened Polyethylene 64% glycol 200 MW Initial Viscosity 1800 cP Initial density 1.13 g/ml Pounds of calcium lignosulfo- 3.3 nate per U.S. gallon Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month 0% None 3 months 0% None
[0067] The above compositions are easily pourable or pumpable
Example 18
Control Calcium Lignosulfonate Suspension
[0068] This example compares the suspension properties of calcium lignosulfonate to example 17 without the use of the hydrogenated castor wax suspension agent. 105 grams of a powdered calcium lignosulfonate is dispersed into 195 grams polyethylene glycol (200 MW) making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight Calcium lignosulfonate 35% Polyethylene glycol 200MW 65% Initial Viscosity 860 cP Initial density 1.13 g/ml Pounds of calcium lignosulfonate per U.S. gallon 3.3 Properties on aging Separation Packing 24 hours 5% Separation in the middle of the column easy to remix 7 days 24% Triphase separation. Upper phase crusty and sticky, middle phase is clear liquid, bottom phase is hard packed; difficult to remix 1 month 24% Triphase separation. Upper phase crusty and sticky, middle phase is clear liquid, bottom phase is hard packed; difficult to remix 3 months 26% Triphase separation. Upper phase crusty and sticky, middle phase is clear liquid, bottom phase is hard packed; difficult to remix
Example 19
Inventive Ethylenediaminetetraacetic Acid Suspension
[0069] Ethylenediaminetetraactetic acid (EDTA) is a well known chelating agent for metal ions. EDTA is used in a wide variety of applications including agriculture, cleaning products, oilfield, paper, personal care, and metal working among others. The low water solubility of EDTA (<0.1% at 25° C.) makes it difficult to supply as an aqueous solution in the acid form. EDTA is frequently converted to a salt to achieve water solubility, but this is an unnecessary if the system pH is acidic and the concentration at use dilution is soluble. 122.5 grams of a EDTA and 7 grams of Rheocin® are dispersed into 221.5 grams pre-thickened polyethylene glycol (200 MW) containing 3.5 grams thickening silica, specifically CAB-O-SIL® TS-530 making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight EDTA 35% Rheocin ® 1% Pre-thickened Polyethylene glycol 200MW 63% Initial Viscosity 3100 cP Initial density 1.29 g/ml Pounds of EDTA per U.S. gallon 3.76 Properties on aging Separation Packing 24 hours 0% None 7 days 0% None 1 month <1% None 3 months 2% None
[0070] The above compositions are easily pourable or pumpable
Example 20
Control Ethylenediaminetetraacetic Acid Suspension
[0071] This example compares the suspension properties of EDTA to example 19 without the use of the hydrogenated castor wax suspension agent. 129 grams of a EDTA is dispersed into 240 grams polyethylene glycol (200 MW) making up the balance in a 600 ml beaker. The mixture is agitated using an overhead mixer at 700 rpm for a period of 1 hour. At this time the viscosity of the mixture is measured on a Brookfield RV viscometer at 20 rpm using a #4 spindle. A portion of the contents is transferred to a 100 ml graduated cylinder for subsequent measurement of the supernatant separation over time. The balance of the material is transferred to another container for evaluation of particle packing and other properties as desired.
Composition: % by weight EDTA 35% Polyethylene glycol 200MW 65% Initial Viscosity 300 cP Initial density 1.26 g/ml Pounds of EDTA per U.S. gallon 3.7 Properties on aging Separation Packing 24 hours 43% Soft packing, difficult to remix 7 days 46% Hard packing, very difficult to remix 1 month 48% Hard packing, very difficult to remix 3 months 51% Hard packing, very difficult to remix
[0072] Although the present invention has been described in terms of the foregoing embodiment, such description has been for exemplary purposes only and, as will be apparent to one of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope, accordingly, is not to be limited in any respect by the foregoing description; rather, it is defined only by the claims that follow.
|
Liquid suspensions of particles in non-aqueous solvents are extremely stable over long periods of time with minimum separation of the solvent and no hard packing of the dispersed particles. The suspensions enable a user to rapidly add the suspension to water and to mix at low speeds without generating fugitive dust in the process. In addition, a liquid dispersion can provide an easy to use liquid containing higher concentrations of the active dispersed phase than can be accomplished by simply preparing an aqueous solution of the dispersed phase. Alternatively, highly water-soluble particles may also be suspended which have poor storage, freeze/thaw, or heat/cool stability. In some cases, liquid dispersions can yield controlled release of the dispersed phase because the dispersed phase is not in aqueous solution. The suspensions are environmentally safe and biodegradable and may be used in environmentally sensitive applications, such as for oil well treating fluids for offshore areas. The suspensions exhibit minimal oil or grease upon dilution and contain no surfactants that which can sometimes add to the oil and grease determination. The suspensions and the fluids produced by diluting the fluids to a working concentration of dispersed phase exhibit low toxicity to marine organisms and to humans. The suspension can be manufactured from ingredients suitable for use in personal care applications, such as cosmetics, shampoos and the like; from ingredients suitable for use in indirect contact with food; and from ingredients that are exempt from regulations as adjuvants for agricultural pesticides.
| 2
|
FIELD
The present invention relates to control systems and more particularly to a control system for a torque converter.
BACKGROUND
Vehicles incorporating an automatic transmission typically include a torque converter disposed between the automatic transmission and an engine of the vehicle. In a first mode, the torque converter transmits rotational energy from the engine to the transmission to allow the transmission to rotate wheels of the vehicle. In a second mode, the torque converter receives rotational energy from the engine but prevents such energy from rotating the transmission and, thus, the wheels of the vehicle. The torque converter essentially acts as a fluid coupling between the engine and the transmission that allows the engine to drive the wheels of the vehicle via the transmission in the first mode while allowing the engine to continue running without driving the wheels of the vehicle (i.e., when the vehicle is stopped, for example) in the second mode.
The input to the torque converter from the engine rotates generally at a higher speed than an output of the torque converter. For example, a conventional torque converter may include an impeller directly driven by the engine and a turbine coupled to an input of the transmission and rotatably driven by movement of fluid within the torque converter caused by rotation of the impeller. The impeller typically rotates at a higher speed than the turbine during operation. This difference in speed between impeller and turbine is referred to as “slippage,” which directly affects performance of the vehicle, as the slippage rate dictates how far an accelerator must be depressed prior to a vehicle being moved from rest, for example. The degree of slippage may be controlled by selectively applying a force to a converter clutch disposed within the torque converter, which, when applied, causes rotational speed of the impeller to more closely approximate that of the turbine. Generally speaking, a high degree of slippage indicates a high torque transfer and a high torque multiplication. Such high slippage also results in high energy losses due to the friction loss associated with directing fluid from the impeller towards the turbine when operating at high speeds.
Conventional control systems may be used in conjunction with a torque converter to apply a form of feedback control. For example, a feedback control system using an error signal that measures slip across the converter clutch may be used to control a pressure of fluid disposed within the torque converter and, thus, the degree to which the converter clutch is applied. While conventional control systems adequately control slip between the impeller and the turbine, conventional control systems mainly employ feedback control and therefore are typically slow to react to a change in driving conditions.
For example, when an accelerator is depressed, the error measured across the converter clutch (i.e., the difference in speed between the impeller and turbine) is great relative to the desired slip speed. As such, some time is required to allow oil pressure to sufficiently build up within the torque converter and exert a force on the converter clutch to allow the turbine speed to approximate that of the impeller to drive the transmission and, thus, the turbine, at a desired slip speed. This increased time results in a delay in acceleration of the vehicle and/or an oscillation in slip speed, and therefore reduces the performance and efficiency of the torque converter and vehicle.
SUMMARY
A powertrain for a vehicle includes an engine having an output and a transmission selectively driven by the output of the engine. A torque converter is disposed between the engine and the transmission for selectively coupling the output of the engine to the transmission. A controller is in communication with the engine and the torque converter and controls a pressure within the torque converter based on an input parameter supplied to the engine.
A method of controlling a vehicle includes detecting a torque demand on an engine of the vehicle, generating a signal based on the torque demand, and supplying the signal to a control valve. The method further includes operating the control valve based on the supplied signal, supplying fluid to a torque converter associated with the engine based on the opening of the valve, and driving a transmission based on an output of the torque converter to propel the vehicle.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a partial cross-sectional view of a torque converter associated with a transmission and a vehicle engine;
FIG. 2 is a partial cross-sectional view of the torque converter of FIG. 1 in communication with a control system in accordance with the principles of the present teachings; and
FIG. 3 is a schematic representation of the control system of FIG. 2 .
DETAILED DESCRIPTION
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
A torque converter 10 is provided and includes a housing 12 , an impeller 14 , a turbine 16 , and a clutch 18 . The housing 12 is rotatably driven by an engine 20 and selectively transmits rotational energy received from the engine 20 to a transmission 22 via the impeller 14 , turbine 16 , and clutch 18 . In one mode of operation, the torque converter 10 receives rotational energy from the engine 20 and transfers the rotational energy to drive the transmission 22 via the impeller 14 , turbine 16 , and clutch 18 to propel a vehicle (not shown) at a desired speed.
As shown in FIG. 1 , the housing 12 is fixed for rotation with the impeller 14 such that when the housing 12 is rotated by the engine 20 , the impeller 14 is concurrently rotated therewith. Conversely, the turbine 16 is fixed for rotation with an input to the transmission 22 and is therefore not directly coupled to the impeller 14 . Rotation of the turbine 16 and clutch 18 is accomplished when the housing 12 and impeller 14 are rotated and the rotational energy of the impeller 14 is transferred to the turbine 16 via a fluid medium, such as, but not limited to, oil or transmission fluid. Rotation of the turbine 16 and clutch 18 may also be accomplished when the clutch 18 is either fully engaged with the housing 12 (i.e., directly attached to the housing 12 for rotation therewith) or positioned in close proximity to the housing 12 . In either configuration, rotational energy from the impeller 14 is transferred to the turbine 16 at least partially by the clutch 18 acting on or near the housing 12 .
The impeller 14 includes a series of blades 24 that circulate fluid within the torque converter 10 . The turbine 16 similarly includes a series of blades 26 that receive fluid from the impeller 14 and cause rotation of the turbine 16 relative to the impeller 14 when the impeller 14 is rotatably driven by the engine 20 .
When the housing 12 is rotated by the engine 20 , the impeller 14 is concurrently rotated therewith such that the blades 24 of the impeller 14 impart a force on the fluid disposed within the torque converter 10 . The force applied to the fluid causes the fluid to move generally away from the impeller 14 and towards the turbine 16 . Sufficient movement of the fluid away from the impeller 14 and towards the turbine 16 causes the turbine 16 to rotate. Because the turbine 16 is rotated under fluid force received from the impeller 14 , the impeller 14 and the turbine 16 act as a “fluid coupling” between an output 21 of the engine 20 and an input 23 of the transmission 22 .
The clutch 18 is attached to the turbine 16 via a damper 28 that connects the clutch 18 to the input 23 of the transmission 22 . The clutch 18 selectively engages a clutch piston or bracket 30 , which is fixed for rotation with the damper 28 . When the clutch 18 is fixed for engagement with the bracket 30 , the clutch 18 is fixed for rotation with the housing 12 and impeller 14 . Because the clutch 18 is fixed for rotation with the turbine 16 (i.e., through the damper 28 ), the turbine 16 is similarly fixed for rotation with the housing 12 and impeller 14 when the clutch 18 is fixed for rotation with the bracket 30 and housing 12 .
Movement of the clutch 18 within the torque converter 10 is accomplished by regulating the pressure of fluid disposed within the torque converter 10 . For example, the pressure within the torque converter 10 may be regulated by increasing the volume of fluid within the torque converter 10 to selectively move the clutch 18 towards the housing 12 . When the clutch 18 is moved in close proximity to the bracket 30 , the turbine 16 rotates at a speed that approximates the speed of the impeller 14 . In other words, the closer the clutch 18 is to the housing 12 , the closer the rotational speed of the turbine 16 approximates that of the impeller 14 . When the clutch 18 is fully engaged with the housing 12 , such that the clutch 18 is fixed for rotation with the housing 12 , the speed of rotation of the turbine 16 is substantially identical to that of the housing 12 and impeller 14 .
As noted above, the pressure acting on the clutch 18 generally dictates the speed of the turbine 16 relative to the impeller 14 (i.e., the slip speed). For example, when the pressure within the torque converter 10 is high, the impeller 14 more closely approximates the speed of the turbine 16 due to the proximity of the clutch 18 to the housing 12 and the inertial forces acting on the transmission 22 .
The energy imparted on the impeller 14 by the engine 20 is transferred to the turbine 16 via a fluid medium (i.e., the fluid disposed within the torque converter 10 ), some of the energy imparted on the fluid by the impeller 14 is lost due to friction and heat associated with the rotating impeller 14 and moving fluid. Therefore, the turbine 16 typically rotates at a slower speed when compared to the rotational speed of the impeller 14 . This difference in rotational speed between the impeller 14 and the turbine 16 is referred to as “slip.” Applying a force to the clutch 18 such that the clutch 18 moves in close proximity to the housing 12 reduces the slip across the torque converter 10 and causes the impeller 14 to approximate the rotational speed of the turbine 16 . When the clutch 18 is fully engaged with the housing 12 , the turbine 16 is essentially fixed for rotation with the impeller 14 and therefore rotates at substantially the same speed as the impeller 14 . When the turbine 16 is fixed for rotation with the impeller 14 , the torque converter 10 is operating in a “zero-slip” state.
With continued reference to FIG. 1 , operation of the torque converter 10 will be described in detail. When a vehicle (not shown) is initially started, the vehicle is at rest and the engine 20 is providing a rotational output. The rotational output is received by the housing 12 and causes the housing 12 and impeller 14 to rotate. Rotation of the housing 12 and impeller 14 applies a force on the fluid disposed within the torque converter 10 via the blades 24 of the impeller 14 . If the vehicle is at idle and brakes (not shown) of the vehicle are applied, the rotational energy supplied to the housing 12 and impeller 14 does not cause sufficient rotation of the turbine 16 to overcome the force applied to wheels (not shown) of the vehicle and the vehicle remains at rest.
When an accelerator 32 is depressed, a greater torque demand is required of the engine 20 . A throttle 34 of the engine 20 responds to the increased torque demand and causes the output of the engine 20 to be increased. Increasing the output of the engine 20 causes the housing 12 and impeller 14 to rotate at greater speeds. The increased rotational speed of the impeller 14 similarly causes the blades 24 to rotate at a higher speed and impart a greater force on the fluid disposed within the torque converter 10 . The increased force applied to the fluid causes the fluid to further rotate the turbine 16 and propel the vehicle. At this point, the vehicle will be driven forward unless a sufficient force is applied to the brakes to maintain the vehicle at rest.
Assuming the brakes are released and the depression of the accelerator 32 causes the vehicle to move forward, slippage between the impeller 14 and turbine 16 is experienced such that energy is lost in transferring fluid force from the impeller 14 to the turbine 16 . To mitigate these losses, more fluid may be introduced into the torque converter 10 to apply pressure on the clutch 18 and cause the clutch 18 to move into close proximity to the housing 12 .
As described above, movement of the clutch 18 into close proximity with the housing 12 causes the turbine 16 to more closely mimic the rotational speed of the impeller 14 . Allowing the turbine 16 to mimic the rotational speed of the impeller 14 allows the vehicle to be more responsive to engine speed and to operate more efficiently.
With particular reference to FIG. 2 , a control system 36 is provided for use with the torque converter 10 . The control system 36 includes a feed-forward module 38 and a feedback module 40 . The feed-forward module 38 and feedback module 40 cooperate to provide an output signal for controlling a valve 42 . The valve 42 may be a solenoid valve such as, for example, a variable-force solenoid (VFS) or a pulse-width modulated (PWM) solenoid. Controlling the valve 42 directly controls the volume of fluid supplied to the torque converter 10 , and thus, controls the pressure within the torque converter 10 to control the proximity of the clutch 18 relative to the housing 12 .
The feed-forward module 38 attempts to mitigate a delay between depression of the accelerator 32 and the torque required to maintain the same amount of slippage when the engine speed increases (i.e., caused by depression of the accelerator 32 ) by estimating the required pressure of fluid needed within the torque converter 10 based on a position of the accelerator 32 . When the accelerator 32 is initially depressed, a volume of fluid enters the torque converter 10 and applies a force on the bracket 30 . Because the force applied to the turbine 16 from the impeller 14 and movement of the clutch 18 into close proximity to the housing 12 is largely dependent on the pressure of fluid disposed within the torque converter 10 , there may be a delay between depression of the accelerator 32 and the torque required to compete with the increasing engine torque.
The feed-forward module 38 attempts to mitigate this delay by anticipating the required pressure within the torque converter 10 based on the angle (i.e., the depression) of the accelerator 32 . While the angle of the accelerator 32 will be described hereinafter, the feed-forward module 38 may use other vehicle operating parameters that provide an indication of the torque demand on the engine 20 . For example, the feed-forward module 38 may receive information regarding the position of the throttle 34 , which indirectly supplies information as to the angular position of the accelerator 32 .
Once the feed-forward module 38 receives information as to the torque demand on the engine 20 , either from the position of the accelerator 32 and/or the position of the throttle 34 , the feed-forward module 38 may estimate the requisite pressure needed within the torque converter 10 to achieve a desired torque capacity of the torque converter 10 and maintain the slip across the impeller 14 and turbine 16 .
Anticipating the pressure required within the torque converter 10 quickly reduces slip between the turbine 16 and the impeller 14 by exerting a force on the clutch 18 via the added fluid. For example, if the vehicle is traveling at a relatively low speed and the accelerator 32 is depressed such that a large increase in speed and, thus, a large increase in torque demanded on the engine 20 are required, a great difference in rotational speed between the impeller 14 and turbine 16 is experienced. When the vehicle is operating at the lower speed, the slip between the impeller 14 and the turbine 16 is greater than when the vehicle is operating at a higher speed. The difference in slip between the impeller 14 and turbine 16 may be overcome by supplying the torque converter 10 with an increase in fluid generally within the torque converter 10 .
This increase in fluid applies a force to the clutch 18 and allows the clutch 18 to move into close proximity with the housing 12 , thereby allowing the turbine 16 to rotate at a speed that more closely approximates the impeller 14 . Anticipating the volume of fluid required within the torque converter 10 to sufficiently move the clutch 18 into proximity with the bracket 30 to achieve a desired slip between the impeller 14 and the turbine 16 allows the vehicle to operate more efficiently and directly respond to depression of the accelerator 32 .
The feedback module 40 works in conjunction with the feed-forward module 38 to “fine tune” the estimation performed by the feed-forward module 38 . The feedback module 40 may receive the slip speed between the impeller 14 and turbine 16 and output an error. The output error may be fed into the feed-forward module 38 to adjust the amount of fluid within the torque converter 10 . The signal output from the feedback module 40 may be a proportional, integral, derivative (PID) signal that continuously varies the duty cycle of the valve 42 .
The following summarizes operation of the feed-forward module 38 and feedback module 40 and provides algorithms for use by both modules 38 , 40 in controlling the torque converter 10 . During operation of the torque converter 10 , the turbine 16 is engaged with the transmission 22 . Therefore, the inertia of the turbine 16 can be assumed as an infinite when compared with that of the engine 20 . When pressurized fluid is supplied to the torque converter 10 to engage and release the clutch 18 , controlling the slip speed indirectly controls the engine speed. The following equation demonstrates that any acceleration change of the engine 20 is equal to a difference between engine torque and the sum of the torque converter transmitted torque and clutch torque.
T e −T t −T cc =( I e +I t )α e
Solving for the torque of the clutch 18 , yields the following relationship.
T cc =T e −T t −( I e +I t )α e
The above relationship demonstrates that the torque in the clutch 18 is equal to the engine torque (T o ) minus the torque transmitted by the torque converter (T t ) and engine turbine inertia torque ( 1 e α e ). The clutch torque capacity at given clutch pressure is given by the following relationship, where μ f is the friction coefficient of the friction material, R f is the effective radius of the friction material, and A f is the friction material area.
T cc =μ f R f A f P cc
During control of the torque converter 10 , a duty cycle of the valve 42 can be continuously modulated to adjust the pressure exerted on the clutch 18 to control the torque of the clutch 18 . The following relationship provides an expression that yields the clutch torque.
P
cc
=
T
e
-
T
t
μ
f
R
f
A
f
+
I
e
+
I
t
μ
f
R
f
A
f
e
s
Δ
t
From above equations, we can see that the duty cycle control of the valve 42 for the clutch pressure is not only dependent on the slip speed error (i.e., the error between the impeller 14 and the turbine 16 ), but also must include the engine torque and torque converter torque. If engine throttle data is used to predict the engine and torque converter torques, the first term
( T e - T t μ f R f A f )
in the above equation for clutch torque (P cc ) is a feed forward control term and the second term
( I e + I t μ f R f A f e s Δ t )
is a feedback control term that accounts for an inertia (I t ) of the housing ( 12 ) and impeller ( 14 ), as well as a desired acceleration (e s /Δt). The first term may be used by the feed-forward module 38 while the second term may be used by the feedback module 40 .
The feed forward module 38 is an anticipatory control to reduce system delay, as described above. The feedback module 40 determines a slip error based on an error between a current operating slip and a desired slip required to produce a desired clutch pressure on the clutch 18 . The feedback module 40 may generate a signal that is used to vary the slip speed and is fed back to the feed-forward module 38 to enhance stability of the duty cycle signal supplied to the valve 42 .
During steady state, the feedback module 40 may employ PID control to continuously adjust the slip error without considering the engine torque and torque converter torque. However, the system delay would inevitably cause slip speed swing and oscillating during periods of transient operations. To improve control quality, engine and torque converter torques should be taken into consideration. One algorithm for controlling the torque converter 10 is provided below.
The first step in controlling the torque converter 10 is to calculate the slip error using the following equation.
N s =N e −N t, N ds =f ( THR,N t ), e s =N s −N ds
Once the slip error is determined, the minimum fluid pressure for application on the clutch 18 can be determined using the following relationship when the clutch 18 is at or about the zero point (i.e., when the torque converter 10 is operated solely by fluid pressure and not by movement of the clutch 18 into engagement with or close proximity to the housing 12 ) where T em is a temperature of the fluid disposed within the torque converter 10 .
P min =P ffad (0, T em )+ P offset ( N t )
The bypass clutch torque may be determined by the following expression, where T con is the torque-converter torque.
T′ cc =T eng −T con ( N e ,N t )
A correction for the clutch torque during periods of idle or steady-state part throttle is provided by the following equation.
T c =T eng −T con ( N e ,N t )
Finally, the corrected clutch torque is a follows.
T cc =T′ cc −T c
The anticipated clutch torque may then be determined by the following relationship.
T
antcc
=
T
eng
+
K
tt
Δ
THR
THR
-
T
con
(
N
ds
,
N
t
)
The anticipated clutch torque may then be applied to the torque converter 10 to drive the torque converter 10 at a desired slip speed.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
|
A powertrain for a vehicle includes an engine having an output and a transmission selectively driven by the output of the engine. A torque converter is disposed between the engine and the transmission for selectively coupling the output of the engine to the transmission. A controller is in communication with the engine and the torque converter and controls a pressure: within the torque converter based on an input parameter supplied to the engine.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This technology relates to pipe couplings. In particular, this technology relates to tools for deflecting spray from between flanges of flanged pipe couplings.
[0003] 2. Brief Description of Related Art
[0004] Occasionally, when disconnecting the bolts from the flanges of a pipe coupling, some liquid may spray out of the coupling, even though the flow line may have been relieved of pressure. Such spray may be hazardous to workers, and also to the environment. For example, the fluid that sprays out of the coupling ay be oil, or a dangerous chemical. If such fluid sprays onto a worker, it may injure the worker. In addition, if such oil or chemical sprays to a shop environment, it may cause undesirable conditions, such as slip and fall hazards in the vicinity of the spray. Furthermore, if such oil or chemical sprays into the natural environment, it may pollute, or otherwise contaminate the environment.
[0005] Shields for use in blocking spray from pipe couplings are known in the art. For example, the device of U.S. Pat. No. 5,470,110 is a shield for blocking spray from a worker to protect the worker. The shield provides a flexible band that a blocks spray around a portion of the flanges of a pipe coupling. The purpose of the shield is to protect the particular worker loosening bolts on the flanges, while still allowing the spray to exit the coupling away from the worker. While such a shield may serve the limited purpose of protecting the worker standing directly behind the shield, it has many shortcomings. For example, in situations where a second worker is nearby, the shield would not necessarily protect the second worker. In addition, because the shield still allows the spray to exit the coupling, albeit in a direction away from the worker, the spray may still harm the environment,
SUMMARY OF THE INVENTION
[0006] Disclosed herein is a spray deflector for blocking discharge from a flanged pipe coupling having a pair of flanges positioned adjacent one another and separated by a gap. The spray deflector has a strap with first and second ends that is configured to circumferentially surround the flanges and cover the gap. The spray deflector also has a tensioning mechanism for increasing or decreasing the tension in the strap around the flanges.
[0007] The tensioning mechanism of the spray deflector includes a lever having an end pivotally coupled to the first end of the strap, It also has a clamp pin mounted on the second end of the strap, and an adjustment pin on a side of the damp pin opposite the first end of the strap. Holes extend through ends of the damp pin and adjustment pin, and extend generally along a length of the strap, In addition, the tensioning mechanism includes a U-shaped bolt having threaded ends, and a curved mid-portion looped around the lever, so that portions of the bolt on opposing ends of the curved mid-portion are generally parallel and project through the holes of the clamp pin and the adjustment pin. A threaded fastener may be mounted onto each threaded end of the U-shaped bolt on a side of the adjustment pin opposite the clamp pin, so that when the lever pivots in a direction away from the second end, contact between the lever and bolt urges the second end of the strap towards the first end, and transfers a tension force into the strap, The spray deflector is configured so that adjusting the positions of the threaded fasteners on the threaded ends of the I-shaped bolt selectively adjusts the magnitude of the tension force.
[0008] Also disclosed herein is a method of deflecting spray while disconnecting fasteners of a flanged pipe coupling having a pair of flanges. According to the method, a spray deflector as described herein is positioned with its strap over a gap between the flanges of the flanged pipe coupling so that strap substantially covers the gap around the circumference of the flanges. Tension in the strap is then increased so that the strap blocks spray from exiting the flanged pipe coupling via the gap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present technology will be better understood on reading the following detailed description of nonlimiting embodiments thereof, and on examining the accompanying drawings, in which:
[0010] FIG. 1 is a perspective view of a flanged pipe coupling and a spray deflector according to an embodiment of the present technology;
[0011] FIG. 2 is a side cross-sectional view of the flanged pipe coupling taken along line 2 - 2 of FIG. 1
[0012] FIG. 3 is a perspective view of the spray deflector according to one embodiment of the present technology; and
[0013] FIG. 4 is an enlarged view of a portion of the spray deflector as indicated by area 4 of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The foregoing aspects, features, and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements, In describing the preferred embodiments of the technology illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the technology is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
[0015] FIG. 1 is a perspective view of a flanged pipe coupling 10 according to an embodiment of the present technology, and FIG. 2 is a cross sectional side view of the flanged pipe coupling 10 taken along line 2 - 2 of FIG. 1 As best shown in FIG. 2 , the flanged pipe coupling 10 includes flanges 12 , 14 having flange faces 16 , 18 . Flange faces 16 , 18 are oriented in a plane normal to the longitudinal axis 20 of a pipe 22 which carries the flanges 12 , 14 . The flanges 12 , 14 are generally configured so that the flange faces 16 , 18 are adjacent to one another upon assembly of the flanged pipe coupling 10 . Optionally, a seal 24 may be inserted between the flange faces 16 , 18 to seal the interface between the flange faces 16 , 18 . The seal 24 may have a thickness T so that when the flanges 12 , 14 are aligned with the seal 24 between them, the flanges 12 , 14 are not able to come directly into contact with one another, Thus configured, the flanged pipe coupling 10 includes a gap 26 between the flanges 12 , 14 .
[0016] In certain embodiments, the flanges 12 , 14 are secured relative to one another with fasteners, which may be nuts 28 and bolts 30 . In such embodiments, assembly of the flanged pipe coupling 10 includes aligning the flanges 12 , 14 so that holes 32 in the flanges 12 , 14 are aligned, and inserting the bolts 30 through the holes, Each bolt 30 may be inserted into its corresponding hole 32 until the bolt head 34 , which has a diameter greater than the diameter of the hole 32 , comes into contact with an outer surface of the flange 14 . Thus inserted, each bolt 30 is long enough that it extends through the holes 32 in flanges 12 , 14 , and the threaded end 36 of each bolt 30 extends beyond the outer surface of flange 14 . A threaded nut 28 is threaded onto the threaded end 36 of each bolt 28 and tightened, thereby pulling the flanges 12 , 14 toward one another, and compressing the seal 24 therebetween, When compressed in this way, the seal 24 creates a fluid tight seal that prevents fluid inside the pipes 22 from leaking through the coupling 10 . Depending on pressure requirements of the flanged pipe coupling 10 , any number of bolts may be used to fasten the flanges 12 , 14 . Typically, the bolts 30 are substantially evenly spaced around the flanges 12 , 14 .
[0017] To disassemble the flanged pipe coupling 10 , the bolts 30 are unfastened from nuts 28 so the flanges 12 , 14 can be separated. Sometimes, as the bolts 30 are unfastened, some liquid from within the pipes 22 and the coupling 10 may spray out of the coupling 10 . This may be due to residual pressure in the pipes 22 and the coupling 10 , or for other reasons. Such spray is undesirable because it may be hazardous to the worker performing the disassembly, or to other nearby workers. In addition, such spray may be undesirable because, depending on the nature of the sprayed fluid, it may be harmful to the environment around the coupling 10 , or its presence in the work environment outside the coupling 10 may create a hazardous work environment.
[0018] In order to limit this spray upon disassembly of the coupling, and as best shown in FIGS. 1 and 3 , a spray deflector 38 may surround the flanges 12 , 14 of the coupling 10 , and cover the gap 26 therebetween. As shown, the spray deflector 38 may include an elongate strap 40 , wide enough to span the gap 26 , and long enough to substantially surround the flanges 12 , 14 . When positioned over the gap 26 , the spray deflector 38 will block spray that may exit the coupling 10 when the nuts 28 and bolts 30 are loosened.
[0019] Referring to FIG. 3 , the spray deflector 38 also includes a tensioning mechanism 42 configured to increase or decrease the tension in the strap 40 around the circumference of the flanges 12 , 14 . The tensioning mechanism 42 may include a pivoting tensioning lever 44 that is pivotally attached to a base 46 . As shown in FIG. 4 , the tensioning lever 44 may be attached to the base 46 with a pin 48 . The pin 48 restricts axial and radial movement between the tensioning lever 44 and the base 46 , but allows circumferential rotation of the tensioning lever 44 relative to the base 46 . The base 46 is attached to, or formed integrally with, a first end 50 of the strap 40 . In some embodiments, the base 46 may be attached to the first end of the strap 50 using nuts 70 and bolts 72 .
[0020] Referring back to FIG. 3 , the tensioning mechanism 42 may also include a clamp pin 52 , an adjustment pin 54 , and a tensioning bolt 56 . The clamp pin 52 may be configured for attachment to a second end 58 of the strap 40 . For example, in some embodiments, the second. end 58 of the strap 40 may surround the clamp pin 52 and attach to itself, as shown in FIG. 3 , The tensioning bolt 56 may have a U-shape, including a curved portion 60 and legs 62 . The tensioning bolt 56 may be configured so that the legs 62 pass through holes 64 in the clamp pin 52 , and the curved portion 60 is rotatably engaged with the tensioning lever 44 at a position forward of the pin 48 . The legs 62 have a smaller diameter than the holes 64 in clamp pin 52 so that the legs 62 can freely slide axially relative to the holes 64 .
[0021] The portion of the legs 62 opposite the clamp pin 52 from the tensioning lever 44 may be configured to engage the adjustment pin 54 . In the embodiment shown in FIG. 3 , the legs 62 have threaded ends 66 and pass through the adjustment pin 54 . A nut 68 threadedly engages each of the legs 62 to prevent the adjustment pin 54 from sliding off the legs 62 and disengaging from the tensioning bolt 56 . In the embodiment shown in FIGS. 1 and 3 , the spray deflector is configured so that when in place on the flanges 12 , 14 , the strap 40 of the spray deflector 38 may substantially surround the whole circumference of the flanges 12 , 14 , excepting only where the tensioning bolt 56 of the tensioning mechanism 42 bridges the gap between the first and second ends 50 , 58 of the strap 40 . Because the strap 40 substantially surrounds the whole circumference of the flanges 12 , 14 , the spray is restrained from reaching any workers in the vicinity of the coupling 10 , or the environment.
[0022] When configured as described herein, and shown in FIGS. 1 and 3 , the tensioning mechanism 44 is capable of increasing or decreasing the tension in the spray deflector 38 around the flanges 12 , 14 . For example, when the tensioning lever 44 is in an up position (not shown), the curved portion 60 of the tensioning bolt is positioned upward and away from the first end 50 of the strap 40 . Conversely, when the tensioning lever 44 is in the down position of FIG. 3 , the curved portion 60 of the tensioning bolt is positioned downward and close to the first end 50 of the strap 40 from contact with the lever 44 . Thus, as the tensioning lever 44 pivots from an upward to a downward position and back, the curved portion 60 of the tensioning bolt 56 is respectively moved toward and away from the first end 50 of the strap 40 .
[0023] As the U-shaped portion 60 of the tensioning bolt 56 moves toward and away from the first end 50 of the strap 40 , the legs 62 of the tensioning bolt 56 likewise move toward and away from the first end 50 of the strap 40 . As the legs 62 move toward the first end 50 , they pull the adjustment pin 54 into the clamp pin 52 , and then pull both the adjustment pin 54 and the clamp pin 52 toward the first end 50 . Because the second end 58 is attached to the claim pin 52 , the second end 58 is also pulled toward the first end 50 and the tension in the strap 40 is increased around the flanges 12 , 14 . Similarly, as the legs move away from the first end 50 , the adjustment pin 54 also moves away from the first end 50 , and tension on the second end 58 of the strap 40 decreases. The tension applied to the strap 40 can be further adjusted by adjusting the position of the nuts 68 on the legs 62 , which in turn adjusts the position of the adjustment pin 54 toward or away from the first end 50 of the strap 40 .
[0024] The ability to increase or decrease the tension in the strap 40 of the spray deflector 38 is advantageous because different tensions are needed during different phases of use of the spray deflector 38 . For example, a decreased tension is desirable during installation of the spray deflector 38 because the deflector 38 moves into place over the gap 26 between the flanges 12 , 14 . However, an increased tension is desirable while disconnecting the bolts of the flange during adjustment, maintenance, or disassembly, to better contain spray.
[0025] An alternate embodiment of the present technology includes a method of using the spray deflector 38 . The method includes positioning the spray deflector 38 over the gap 26 between two flanges 12 , 14 of a flanged pipe coupling 10 so that the strap 40 of the spray deflector substantially surrounds the circumference of the flanges 12 , 14 . The method further includes increasing the tension of the strap 40 by moving the tensioning lever 44 of the tensioning mechanism 42 from an upward position to a downward position, as described above, so that the spray deflector 38 blocks spray from exiting the flanged pipe coupling 10 via the gap 26 . In some embodiments, the method may further include decreasing the tension of the strap 40 by moving the tensioning lever 44 of the tensioning mechanism 42 from a downward to an upward position so that the spray deflector is movable relative to the flanges for repositioning or removal of the spray deflector.
[0026] While the technology has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the technology. Furthermore, it is to be understood that the above disclosed embodiments are merely illustrative of the principles and applications of the present technology. Accordingly, numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present technology as defined by the appended claims.
|
An apparatus for blocking discharge from a flanged pipe coupling, including a s trap configured to surround, and cover a gap between flanges. The apparatus includes a tensioning mechanism with a lever pivotally coupled to the strap, a clamp pin mounted on the opposing end of the strap, and an adjustment pin on a side of the clamp pin opposite the lever. Holes extend through ends of the clamp and adjustment pins. The tensioning mechanism includes a bolt having ends, and a mid-portion looped around the lever, so that portions of the bolt on opposing ends of the mid-portion are generally parallel and project through the holes. A fastener is mounted onto each bolt end on a side of the adjustment pin opposite the clamp pin. When the lever pivots away from the clamp pin, contact between the lever and bolt urges the ends of the strap together, increasing tension therein,
| 5
|
FIELD OF THE INVENTION
The present invention relates to the textile industry, more particularly to banks of spindles for long fibers and short fibers, and has for its object apparatus for the automatic removal of bobbins from a bank of spindles for long fibers and short fibers as well as a process for using this apparatus.
BACKGROUND OF THE INVENTION
At present, the removal of full bobbins from the spindles of a bank of spindles and their replacement by empty bobbins are still, in most cases, operations performed manually and requiring substantial work on the part of the operators who perform this work.
There also exist various semi-automatic and automatic apparatus permitting the performance of these operations. Generally speaking, these involve in the first instance the inclination of the spindle bearing carriage, then the extraction and removal of the full bobbins by means of mechanical devices provided with grippers or manipulating arms, assembling the full bobbins in a region spaced from the empty bobbins and, finally, replacing empty bobbins on the spindles.
Nevertheless, these known devices often have, on the one hand, insufficient precision as to their operation, arising from numerous misfunctions of the corresponding banks of spindles and involving, on the other hand, the non-use of that portion of the empty bobbins necessary for gripping the full bobbins, from which arises a loss of usable length of said empty bobbins.
The present invention has for its particular object to overcome the above drawbacks.
SUMMARY OF THE INVENTION
The invention thus provides an apparatus for the automatic removal of bobbins from a bank of spindles for long fibers and short fibers, characterized in that it is principally constituted, on the one hand, by a carrier fork, movable in a vertical direction and in at least one horizontal direction parallel to the transverse alignment of the spindles of the spindle-carrying carriage, on the other hand by support and manipulation cups for the full bobbins and the empty bobbins, and, finally, by a conveyor for the evacuation of the full bobbins and the feeding of the empty bobbins.
The invention also provides a process for automatic removal of bobbins from a bank of spindles for long fibers and short fibers, using the above apparatus, which process is characterized in that it consists, at the end of winding up on the bobbins, breaking the yarn and disengagement of the full bobbins from their corresponding flyers, lowering the spindle carrier as the case may be, removing said full bobbins from their corresponding spindles and transporting them toward an overhead conveyor, by means of a carrier fork coacting with cups threaded on said spindles and each supporting a bobbin, hanging said bobbins on empty bobbin carriers of said conveyor, the cups remaining unitary with the fork, then detaching an equal number of the empty bobbins from the conveyor by means of said cups, transporting them toward the free spindles of the spindle carrier, threading them together with the cups which support them on said spindles and, finally, disengaging said transporting fork from said threaded cups and bringing it to a disengaged rest position.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following description, which relates to a preferred embodiments, given by way of non-limiting examples, and explained with reference to the accompanying schematic drawings, in which:
FIG. 1 (1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I and 1J) show, in front elevational views with respect to a single bobbin, the principal stages of the process according to the invention;
FIG. 2 is a plan view of the structure of the apparatus according to the invention, shown in the phase of the process corresponding to FIG. 1J, and
FIG. 3 is a plan view of the apparatus shown in FIG. 2, but in the following phase of the process according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, and as shown in FIGS. 1 to 3 of the accompanying drawings, the apparatus for automatic removal of bobbins is principally constituted, on the one hand, by a transporting fork 1, movable in a vertical direction 2 and in at least one horizontal direction 3 parallel to the transverse alignment of the spindles 4 of the spindle-carrying carriage 5, on the other hand, by cups 6 for supporting and manipulating the full bobbins 7 and the empty bobbins 8, and, finally, by a conveyor 9 for evacuation of the full bobbins 7 and for feeding the empty bobbins 8.
According to a first characteristic of the invention, shown particularly in FIGS. 1F, 1G, 2 and 3, the transporting fork 1 is provided with tongues 10 having springs 11 permitting grasping the edges 12 of the cups 6, during the manipulation of the full bobbins 7 or the empty bobbins 8 and thereby to avoid any displacement of said cups 6 relative to the fork 1.
The use of cups 6, threaded on the spindles 4 and supporting the empty bobbins 8 during winding, in combination with the transporting fork 1, increases the precision of the various manipulative stages, and facilitates particularly the centering operations. Moreover, during winding, it is possible to wind up the yarn over all the height of the bobbins 8, the fork 1 not contacting directly the full bobbins 7 and accordingly not requiring any free gripping zone on the bobbins 8.
According to a first modification of the invention, shown in FIGS. 2 and 3 of the accompanying designs, the width l of the transporting fork, 1 corresponds to a fraction of the length of the spindle-carrying carriage 5, said fork 1 being also movable in a direction 13 parallel to said spindle-carrying carriage 5. The automatic removal can be effected, for example, for groups of eight bobbins 8.
The process of automatic removal should thus be repeated as often as there are groups of eight spindles 4 on the spindle-carrying carriage 5. The passage from one group to the other will therefore be effected by displacement of the fork 1 in the direction 13.
According to a second modification of the invention, not shown in the accompanying drawings, the carrying fork 1, comprised as the case may be of several independent segments, extends over all the length of the spindle-carrying carriage 5. The control of this fork 1 can accordingly be either fractional, in the case of a construction of several segments, or general, in the case of a fork 1 of one piece. It is thus possible to effect the removal of all the bobbins 7 in a single operation; there thus results increased production thanks to shorter stoppage of operation of the bank of spindles.
According to another characteristic of the invention, not shown in the accompanying drawings, the automatic removal apparatus according to the invention comprises also a security device actuated during actuation of the transporting fork 1 and provided with audible and/or luminous signal means, said device permitting moreover as the case may be defining a safety zone about the bank of spindles in question.
The invention also has for its object a process for automatic removal of bobbins 7 employing the apparatus described above, which process consists, after the end of winding of the bobbins 7, breaking the yarn and the disengagement of the full bobbins 7 from their corresponding flyers 14, as the case may be by lowering the spindle-carrying carriage 5 (FIG. 1A), in extracting said full bobbins 7 from their corresponding spindles 4 (FIG. 1B) and transporting them toward an overhead conveyor 9 (FIG. 1D), by means of a carrying fork 1 coacting with cups 6 threaded on said spindles 4 and each supporting a bobbin 7, hooking said bobbins 7 to empty bobbin carriers 15 of said conveyor 9 (FIGS. 1E and 1F), the cups 6 remaining unitary with the fork 1, then uncoupling empty bobbins 8 in equal number from said conveyor 9 with the aid of said cups 6 (FIGS. 1G, 1H and 1I), carrying them toward the free spindles 4 of said spindle-carrying carriage 5, threading them together with cups 6 which support them on said spindles 4 (FIGS. 1J and 2) and, finally, disengaging said carrying fork 1 from said threaded cups 6 (FIG. 3) and bringing it into a disengaged rest position.
During the rising of the spindle-carrying carriage 5, a displacement of this latter beyond its normal position, during operation of the bank of spindles, will permit setting to the bottom the empty bobbins 8 on the spindles 4 thanks to abutments 17 disposed on flyers 14.
According to a further characteristic of the invention, and as shown particularly in FIGS. 1A and 1B of the accompanying drawings, the extraction of the full bobbins 7 from their spindles 4 consists first in feeding the fork 1, from its rest position, opposite the spindle-carrying carriage 5 and at the height of the cups 6, then introducing said fork 1 between the spindles 4 by a horizontal translation movement, so as to engage the cups 6 between the tongues 10 with springs 11 and the corresponding slideways 16 and, finally, unthreading the assemblies of cups 6 and bobbins 7 from their corresponding spindles 4 by vertical movement of said fork 1.
The displacement of the presser fingers 18 of the wings 14 to a spaced position during extraction of the bobbins 7 (FIGS. 1B and 1C), will finally permit the emplacement of the empty bobbins 8 (FIGS. 1J and 2) without risk of damaging said presser fingers 18.
This emplacement of the empty bobbins 8, toward the spindles 4, consists in effecting by means of the fork 1 reverse movements from those described above for extraction of the bobbins 7, in reverse order.
As shown in FIGS. 1D to 1I, the operations of hanging the full bobbins 7 and unhanging the empty bobbins 8 are effected by vertical movements of the fork 1, the arrangement of the bobbin carrier 15 on the overhead conveyor 9 corresponding to the arrangement of the spindles 4 on the spindle-carrying carriage 5. Moreover, between the phases shown in FIGS. 1F and 1G, the conveyor 9 moves by a length such that it presents opposite the empty cups an equal number of empty bobbins 8.
The actuation of the fork 1 can be effected for example by mechanical means controlled by electrical, hydraulic or pneumatic devices and controlled as the case may be by a programmable automation.
The tongues 10 could equally according to a modification be actuated by pneumatic or hydraulic means.
Thanks to the invention, it is accordingly possible to proceed with the automatic removal of the assembly or of all or a portion of the spindles 7 from a bank of bobbins 4 and replacing them by empty bobbins 8 by means of a fork 1 coacting with cups 6 for the support and manipulation of the bobbins 7 and the empty bobbins 8, permitting operation with high precision of movement and without direct handling of said bobbins 7 or the said empty bobbins 8.
Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly as to the construction of the various elements, or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.
|
Process and apparatus for the automatic removal of bobbins from a bank of spindles. A transporting fork has a plurality of recesses for simultaneously handling a plurality of spindles. The transporting fork is movable in a vertical direction and in at least one horizontal direction parallel to a bank of spindles on a spindle carrying carriage. A cup is insertable over each spindle for the support and manipulation of bobbins. A conveyor evacuates full bobbins and supplies empty bobbins. The fork releasably retains a cup in each recess whereby each cup can be penetrated by and disengaged from the fork upon movement of the fork in a horizontal direction.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and to a method for manufacturing semiconductor devices that reduces the size of semiconductor devices and improves the yield.
2. Prior Art
One type of semiconductor device assembly method is a tape carrier method. Essentially, in this assembly method, as seen from FIG. 7 , numerous leads 76 consisting of a conductive layer are formed on the upper surface of a carrier film 2 that is made of a band-form heat-resistant resin film. Then, these leads 76 are bonded to bumps that are surface electrodes of semiconductor chips 78 . In addition, these elements are sealed with a resin.
More specifically, in this tape carrier method, the tip ends of the leads 76 formed on the surface of the carrier film 2 , as seen from FIG. 8 , overhang from windows 2 a of the carrier film 2 , and the semiconductor chip 78 is caused to approach the leads 76 from below. Then, the leads 76 and bumps 80 are thermally fused while being heated and pressed from above by a bonding tool that has a heater, thus bonding the leads 76 and bumps 80 . Bonding of the leads 76 and bumps 80 can be done by another way. A molten resin material in which a conductive powder is dispersed and held is applied to the interfacial surfaces of the leads 76 and bumps 80 and then hardened.
In recent years, a flip-chip method is also used. In this method, as seen from FIG. 9 , leads 76 are formed on the surface of a carrier film 82 , and semiconductor chips 78 that are set upside down are caused to approach the leads 76 from above, and boding is performed on the leads and bumps.
However, even in this flip-chip method, there are problems. When achieving a finer pitch, it is likely that more defective products are produced, thus causing yield drop. A detailed investigation of such defective products done by the inventor found the causes of such defective bonding. When the lead 76 contacts a position that is away from the center of the corresponding bump 80 , the application of pressure in this state causes the lead 76 to slip on the upper surface of the bump 80 as shown in FIG. 10 . As a result, the deviation S increases, and the lead 76 falls from the upper surface of the bump 80 .
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a semiconductor device that, in its manufacturing process, is able to prevent slipping between the leads and bumps, thus preventing falling of the leads from the bumps.
A further object of the present invention is to provide a manufacturing method of semiconductor devices that is able to realize a much greater reduction in the size of semiconductor devices and also realize an improvement in the yield.
The above object is accomplished by a unique structure for a semiconductor device in which bumps formed on the surface of a semiconductor chip and leads are set to face each other and bonded, wherein
a recess is formed in the surface of each one of the bumps that faces a lead, the recess comprises guide-surfaces that are inclined surfaces and are formed between the bottom of the recess and the opening edges of the recess, and each of the leads is provided with a projection at one end thereof, the projection being to be bonded to a bump and provided with guided-surfaces that are inclined surfaces.
In this structure, when the bump and the lead are faced and pressed each other, the lead is guided toward the center of the upper surface (or the bottom) of the bump by the guide-surfaces of the bump and by the guided-surfaces of the lead that are inclined. Accordingly, even when the lead contacts a position that is away from the center of the bump, the lead does not fall from the bump. Furthermore, since the lead is guided by the inclined surfaces, a stress acts toward the lead from the opening edges of the bump, and the lead is held firmly on the bump. Accordingly, an assured bonding is performed, reduced size semiconductor devices are produced, and it is possible to realize the improvement in the yield.
In the above structure, the inclined guide-surfaces are formed for the entire periphery of the recess of each bump. Also, the guided-surface are formed so as to be inclined for the entire periphery of each lead and so as to surround a bonding point (a point that is bonded to the corresponding bump) of the lead.
Accordingly, the lead is guided into the recess of the bump from any directions around the entire periphery of the lead.
Furthermore, in the above semiconductor device, the width of the end surface of the lead that faces the bump is set to be narrower than the width of the lead.
By way of designing the end surface of the lead that faces the bump so as to be narrower than the width of the lead, the lead is accurately guided into the recess of the bump. In addition, this structure provides the lead with a structural strength, the deformation thereof is thus prevented, and it is ideal for meeting a required finer pitch.
The above object is further accomplished by unique steps of the present invention for a method for manufacturing a semiconductor device in which bumps formed on the surface of a semiconductor chip and leads are set to face each other and bonded; and in the present invention, the method includes:
a step of forming a recess in the surface of each of the bumps that faces the lead, the recess having inclined surfaces between the bottom of the recess and the opening edges of the recess, and a step of forming a projection at one end of each of the leads, the projection being to be bonded to each of the bumps and provided with guided-surfaces that are inclined surfaces
In this method, each bump has guide-surfaces that are inclined surfaces and each lead has guided-surfaces that are inclined surfaces that mate the inclined surfaces of the bump. Accordingly, when the bump and the lead are faced and pressed each other, the lead is guided into the center of the upper surface (or the bottom) of the bump by the guide-surfaces of the bump and the guided-surfaces of the lead. Accordingly, even when the lead contacts a position that is away from the center of the bump, the lead does not fall from the upper surface of the bump. Furthermore, since the lead is guided by the inclined surfaces of the bump, a stress acts toward the lead from the opening edges of the bump, and the lead is held firmly on the bump. Thus, bonding is performed securely, reduced size semiconductor devices can be produced, and it is possible to realize the improvement in the yield.
In the above method, the inclined guide-surfaces are formed around the entire periphery of the recess of each bump, and the guided-surfaces are formed around the entire periphery of the bonding point (a point that is bonded to the corresponding bump) of each lead. Thus, the lead is guided into the recess of the bump from any directions around the entire periphery of the lead.
Furthermore, in the above method, the width of the end surface of a lead that faces a bump is formed so as to be narrower than the width of the lead. Since the end surface of the lead that faces the bump is narrower than the width of the lead, the lead is accurately guided into the recess of the bump. In addition, the lead has a structural strength, the deformation thereof is prevented, and it is ideal for manufacturing finer pitch semiconductor devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view in cross section that illustrates the bump formation process in one embodiment of the present invention;
FIG. 2 is a perspective view of an obtained bump;
FIG. 3A is a side view of a lead in the lead-side-bump formation process, and
FIG. 3B shows a lead in the lead-side-bump formation process in which half-etching has been performed;
FIG. 4 is a perspective view of a tip end portion of a lead;
FIG. 5 is a front view that illustrates the bonding process of the leads and bumps, showing that the leads and bumps face each other;
FIG. 6 is a front view that illustrates the bonding process of the leads and bumps, showing that the leads and bumps are pressed;
FIG. 7 is a top view of a semiconductor device in one step of a prior art semiconductor device manufacturing process that uses a carrier film;
FIG. 8 is a side view of a semiconductor device in one step of a prior art semiconductor device manufacturing process that uses a carrier film;
FIG. 9 is a side view of a semiconductor device in one step of a prior art semiconductor device manufacturing process that uses flip-chip method; and
FIG. 10 is a front view illustrating a defective lead and bump bonding in a conventional semiconductor device.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows the formation of bumps 10 . The bumps 10 are formed by electroplating.
More specifically, a mask layer 4 consisting of a synthetic resin is first formed by a silkscreen process on portions of the surface of the semiconductor chip 8 except for the electrodes (not shown). As a result, through-holes 4 a are formed in the mask layer 4 . Next, this semiconductor chip 8 is subjected to electroplating, so that a gold-plating layer is grown on the electrodes. The growth of this gold-plating layer is not performed to the point that the gold-plating layer reaches the edges of the through-holes 4 a in the mask layer 4 . Instead, this growth is completed at an intermediate point in the depth of each through-hole 4 a . The growth of the gold-plating layer proceeds along the peripheral wall surfaces of the through-holes 4 a ; as a result, a recess 10 a is formed in the upper surface of each bump 10 . Then, the mask layer 4 is removed by solvent.
As shown in FIG. 2 , the recess 10 a has the shape of a truncated square pyramid, and it has inclined guide-surfaces 10 c between the bottom 10 b and the opening edges 10 d.
FIGS. 3A and 3B illustrate the process of forming a projection or a lead-side-bumps 6 a on a lead 6 .
First, mask layers 7 consisting of a synthetic resin are formed on the tip end portion and base portion (with respect to the direction of length) of the surface of each lead 6 that is held on a carrier film 12 . This surface that has the mask layers 7 is one that faces a corresponding bump 10 (i.e., the upper surface in FIG. 3 A).
Next, this lead 6 is subjected to half-etching as shown in FIG. 3 B. As a result, the portions of the lead 6 that are not masked by the masking layers 7 are etched and removed. Here, a projection or a lead-side-bump 6 a is formed at the tip end portion of the lead 6 that is masked by the masking layer 7 . Since the etching acts uniformly on the surfaces of the material of the lead 6 , the side surfaces of the lead-side-bump 6 a are formed as a guided-surface 6 b . The side surfaces of the guided-surface 6 b are inclined outward from the upper surface side (that faces the corresponding bump 10 ) toward the lower surface side. Then, the mask layers 7 on the lead 6 are removed by solvent.
As shown in FIG. 4 , the guided-surface 6 b of each lead-side-bump 6 a is formed around the entire periphery of the lead-side-bump 6 a.
The bonding of the leads 6 and bumps 10 is performed using a gang bonding method in which all bonding is performed simultaneously for a single semiconductor chip 8 . As shown in FIG. 5 , the carrier film 12 and semiconductor chip 8 are positioned in relative terms so that the leads 6 and bumps 10 are set to face each other. Then, beginning from this state, the respective leads 6 and bumps 10 are pressed toward each other by means of a heated bonding tool (not shown) as shown in FIG. 6 . The width 6 c (see FIG. 4 ) of the surfaces of the leads 6 that face the bumps 10 in FIG. 5 is approximately 6 to 8 micrometers (μm).
Here, as shown in FIGS. 5 and 6 , the center of the lead 6 located in the central position more or less coincides with the center of the corresponding bump 10 . Accordingly, during bonding, the lead-side-bump 6 a contacts the bottom 10 b of the corresponding bump 10 from the beginning and is bonded so that the lead-side-bump 6 a bites of the lead 6 into the bump 10 .
On the other hand, the centers of the leads 6 located in the left and right positions deviate from the centers of the corresponding bumps 10 , and these leads 6 contact the corresponding bumps 10 with a deviation S of, for instance, approximately 5 to 7 micrometers (μm). However, when the leads 6 and bumps 10 are pressed, the leads 6 are guided toward the centers of the upper surfaces of the bumps 10 via the inclined guide-surfaces 10 c of the bumps 10 and the guided-surfaces 6 b (that are also inclined) of the leads 6 . As a result, the attitudes of the leads 6 are corrected. Furthermore, as a result of the leads 6 being guided, stress acts toward the guided-surface 6 b of the lead-side-bumps 6 a from the opening edges 10 d of the bumps 10 . As a result, the leads 6 are firmly held on the bumps 10 . In this case, the change in the attitudes of the leads 6 is accomplished while causing deformation of the carrier film 12 or is accomplished with the constraint of the leads 6 released as a result of the leads 6 leaving the carrier film 12 .
Then, in this state, the leads 6 and bumps 10 are bonded by way of thermal fusion.
In the above embodiment, the leads 6 (more specifically the projections of the leads) are guided toward the centers of the upper surfaces of the bumps 10 by the inclined guide-surfaces 10 c of the recesses 10 a of the bumps 10 and by the inclined guided-surfaces 6 b of the leads 6 . Accordingly, even in cases where the leads (or projections thereof) 6 contact the bumps 10 in positions that are away from the centers of the bumps 10 , the leads 6 are prevented from slipping off of the upper surfaces of the bumps 10 . In addition, since the leads 6 are thus guided, stress acts toward the leads 6 from the opening edges of the bumps 10 , so that the leads 6 are firmly held on the bumps 10 . Accordingly, bonding is performed more securely, and a much greater reduction in the size of the semiconductor device is realized. In addition, the yield is increased.
Furthermore, the inclined guide-surfaces 10 c are formed around the entire circumference of the recess 10 a of each bump 10 . Also, the guided-surface 6 b that are also inclined are formed around the entire circumference of each lead 6 so as to surround the bonding point (an area that is bonded to the corresponding bump 10 ) of the lead. Accordingly, guidance of the leads 6 by the guide-surfaces 10 c and guided-surface 6 b is performed with accuracy in any directions around the entire circumference.
Furthermore, as seen from FIG. 4 , the width 6 c of the surfaces of each lead 6 that face the bumps 10 is formed so as to be narrower than the width 6 d of the leads 6 . Accordingly, the edge portions of the surfaces of the leads 6 that face the bumps 10 are guided with higher reliability by the inclined guide-surfaces 10 c of the bumps 10 . As a result, the leads 6 are guided accurately. In addition, since the width 6 d of each lead 6 is wider than the width 6 c of the surface that faces a bump 10 , the strength of the leads 6 is ensured, a deformation thereof is suppressed. Thus, it is ideal for obtaining a finer pitch.
In the shown embodiment, the recesses 10 a are formed by way of interrupting the formation of the electroplating layers of the bumps 10 . The recesses 10 a , however, can be formed by other methods. The recesses can be made by way of cutting or etching the upper surfaces of the bumps 10 .
Moreover, in the above embodiment, the lead-side-bumps 6 a are formed by way of half-etching the leads 6 . However, the lead-side-bumps 6 a can be formed by other methods. One way to form the lead-side-bumps 6 a or a projection on each of the leads 6 is to cut the lead 6 so that a portion that makes the lead-side-bumps 6 a or a projection is allowed not to be cut and remain. Another way is to separately form the lead-side-bumps 6 a or projections and bond them to the leads 6 .
Furthermore, in the above embodiment, the inclined guide-surfaces 10 c are formed around the entire circumference of the recess 10 a of each bump 10 , and guided-surface 6 b are formed so as to incline around the entire circumference of each lead-side-bump 6 a . However, the guide-surfaces 10 c and/or the guided-surfaces 6 b can be formed partially with reference to the entire circumference of each bump and each lead. For instance, it is possible to form the guided-surface 6 b only on the left and right surfaces of the lead 6 with respect to the direction of width and form the guide-surfaces 10 c in two places in the recesses 10 a so as to correspond to such a guided-surface 6 b.
In the above embodiment, the leads 6 and bumps 10 are bonded by thermal fusion. However, the leads 6 and bumps 10 can be bonded by various other known methods. Thus, they can be bonded by a synthetic resin material in which a conductive powder is dispersed and held. Such methods are within the scope of the present invention.
|
In a semiconductor device, each of the leads is provided with guided-surfaces that are inclined surfaces and each of the bumps is provided with a recess that has guide-surfaces formed by inclined surfaces. The leads are smoothly guided toward the centers of the upper surfaces of the bumps with the aides of the inclined surfaces formed on the leads and bumps, so that the attitude of the leads is corrected and the leads are snugly brought into the recess and prevented form falling off of the bump.
| 7
|
This is a continuation of application Ser. No. 873,860, filed Jan. 31, 1978, which is a continuation of Ser. No. 723,953, filed Sept. 16, 1976, both of which are now abandoned.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to means for preventing squeak in a disc brake and more specifically to removing an abrasion powder formed during the braking action.
SUMMARY OF THE INVENTION
The inventors of the present invention have found that the abrasion powder of a brake adhering to a disc brack rotor at the time of applying the brake constitutes the main cause of a series of such irregularities as
(I) Deterioration of the braking effect of a brake
(II) Generation of a low-frequency noise at the time of applying a brake
(III) Generation of chatter and vibration of the body of a vehicle, and
(IV) Generation of a high-frequency noise (conventionally called a brake squeak)
Now, the purpose of the present invention is to provide a new and novel disc brake for preventing a squeak from being generated at the time of applying a brake and the present invention is specifically intended to cause the disc which is made of heat-resistant material, including glass fiber, asbestos, or the like, to be properly engaged with a disc rotor either at all times or at the time of applying the brake for the purpose of removing an abrasion powder adhering to the disc brake rotor. To put it otherwise, the subject matter of the present device resides in moving such a disc brake device specifically designed for preventing a squeak from being generated and features a disc brake that is provided with a disc that is capable of being put in rotation, a pair of friction-pads arranged in place on the both sides of the said disc and properly engaged with the said disc for braking, and a member that is specifically designed for removing an abrasion powder adhering to the disc at the time of the engagement of the said friction-pads with the said disc.
Other pruposes and the effects of the present invention will be self-evident in view of an illustration of the present invention whereof a detailed description is given below by making reference to the drawings attached hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of the disc brake of the present device,
FIG. 2 is a drawing of the disc brake projected on the plane parallel to the rotating shaft of the disc rotor shown in FIG. 1,
FIG. 3 is a front view of the second embodiment,
FIG. 4 is a plan of what is shown in FIG. 3,
FIG. 5 is a plan of the illustration shown in FIG. 3, and
FIG. 6 is a graph prepared for making a comparison of the pad provided by the present device with a conventional pad in terms of the index of a squeak.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective of the present device, and FIG. 2 is a drawing of a disc brake 2 projected on a plane parallel to the rotating shaft of a disc rotor 1 shown in FIG. 1. A caliper 4 is mounted on a vehicle and supports a pair of friction pad assemblies which are so arranged in place as to be engaged slidably by both surfaces of the disc rotor 1 confronted with the axial direction thereof. Furthermore, the said mounting 3 has an abrasion powder removing member 5 that is engaged with the both surfaces of disc rotor 1 and is specifically designed so as to remove the abrasion powder generated by the frictional engagement of the disc rotor 1 with a friction pad at the time of applying the brake properly fixed in place thereon. The said removing member 5 is kept engaged with the disc rotor 1 at all times; therefore, the said removing member 5 is given a fibrous shape, and glass fiber, a wire brush, or the like is selected for use as such.
The said abrasion powder removing member 5 is recommended to be made of such material as features a high level of heat resistance, since the temperature of the disc rotor 1 rises as high as 400°-500° C., and, in this case, the said abrasion powder removing member 5 is required to be made of a material featuring a high level of abrasion resistance, since the said abrasion powder removing member 5 is kept engaged with the disc rotor 1 at all times.
FIG. 3 is a front view of the second embodiment of the present device, and FIG. 4 is a plan of the illustration shown in FIG. 3. The disc brake shown is one that is supported by a caliper 4, that comes in frictional engagement with the disc rotor 1 at the time of braking. A part of a friction-pad 6 assembly performing the braking function has an abrasion powder removing member, made of such material as is capable of removing abrasion powder, properly set in place thereon. To put it otherwise, the friction-pad 6 has a pad assembly lining 8 fixed thereon supported by a metal lining 7, the said pad lining 8 containing resin, powdered metal, dust rubber and the like, which are formed into abrasion powder and adhere to the disc rotor 1. The abrasion powder removing member 5 specifically designed for removing the said abrasion powder is properly fixed in place on the side of the said metal lining 7 and is spaced from said pad lining 8 by a groove 9.
The abrasion powder removing member 5 is made of, for instance, asbestos, glass fiber, or the like, and is recommended to have a high level of heat resistance, as set forth above. And, the degree of the abrasion thereof is recommended to be the same as, or less in abrasion resistance than that of the pad lining 8.
Shown FIG. 5 is the third embodiment of the present device, wherein the abrasion powder removing member 5 is fitted on a metal lining 7 with a spring 10 interposed in between. In this case, deflected abrasion taking shape in the pad lining 8 causes the abrasion powder removing member 5 to be subjected to deflected abrasion only by a negligible degree, if any, since the abrasion powder removing member 5 is biased by a spring of weak elasticity, and, at the time of braking, the abrasion powder can thus be removed in a more favorable manner, since the abrasion powder removing member 5 is caused to be properly kept in contact with the disc rotor at all times.
It goes without saying that the present device can be applied for proper removal of abrasion powder from the lining not only of the disc brake disclosed herein but also of a drum brake likewise.
Shown in FIG. 6 is a result of the series of experiments conducted for the purpose of displaying the effect of the present device, and shown in this graph is a comparison of a pad having the abrasion powder removing member introduced in the present device fitted in place thereon with a conventional pad, by putting together the frequency of generation of a squeak and the noise level of the squeak, then expressed in terms of an index of the squeak. A represents a conventional pad fitted with no abrasion powder removing member, B represents a pad employing asbestos as the abrasion powder removing member introduced in the present device, and C represents a pad employing glass fiber as the abrasion powder removing member introduced in the present device.
As elucidated in the preceding paragraphs, it is clear and evident that the disc brake fitted with the pad abrasion powder removing member introduced in the present device proves, when compared with a conventional one, to be well capable of eliminating and solving the above-mentioned irregularities involved in the conventional one, and considerably effective in coping with the squeak of a brake among others.
Having described certain embodiments of this invention in detail, it is to be understood that the same have been offered by way of example and that this invention is only to be limited by the scope of the following claims.
|
In order to suppress squeak noise generated at the time of braking of a disc brake, there is provided a member for removing abrasion powder as well as a conventional pair of friction pads which are provided on both sides of the disc. The member is designed so as to remove abrasion powder adhering to the disc at the time of engagement of the disc with the friction pads.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This Application claims priority to provisional application Ser. No. 60/336,062 filed on Oct. 23, 2001, and application Ser. No. 10/277,415 filed on Oct. 22, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the field of seals which mount on a door frame to seal between the door and the frame and, in particular, to seal around the perimeter of overhead garage doors.
[0004] 2. Brief Description of the Related Art
[0005] It is known to provide seals around the perimeter or edge of a door in order to seal out elements, such as for example, air drafts, rain, snow, insects and dust. Most seals are utilized in connection with a door or door frame. There are some seals which are mounted directly on the door. Generally, such seals are mounted on the bottom of the door to maintain a seal with the ground or door sill when the door is closed. Other seals are provided on the door frame, and are configured to seal the door against air drafts, insects, water, and other elements.
[0006] It is known to provide seals for garage doors. Generally, for the most part, garage doors are larger in perimeter than most entry doors. A seal is desirable to be maintained between the door panel and the door frame. Since there is usually some space between the frame and the door, it is desirable to seal that space. Attempts have been made to provide a seal or weather strip for garage doors. These prior seals include strips with a flexible seal which are nailed to a door frame, such as the “Door Seal” disclosed in U.S. Pat. No. 5,784,834 issued on Jul. 28, 1998 to Ellis D. Stutzman. Another example of a door seal is found in U.S. Pat. No. 6,167,657 for a “Weatherstrip Product Formed by Sequential Extrusion of Cellular and Non-Cellular Plastic Resins” issued on Jan. 2, 2001 to Gary Burge, et al. U.S. Pat. No. 5,092.079, issued on Mar. 3, 1992 to Marc A. Brookman, et al., discloses a Weather Seal for a Garage Doorwith a block which pivotally moves in relation to a base member. A “Door Having Hidden Screw Construction” is disclosed in U.S. Pat. No. 5,230,180, issued on Jul. 27, 1993 to Robert C. Tweedt, which provides a plastic edge cap on the latch edge of the door.
[0007] Great Britain patent application no. 2 153 890 A published on Aug. 29, 1985 discloses a “Weather Seal” for a door or window which has a channel-shaped base member and a cover member pivotally attached to the base member by means of a flexible web. Canadian patent application 728,935 provides a soft material which mounts on an attachment member. Great Britain patent application 2 231 361 A published on Nov. 14, 1990, discloses “Draught seals for doors”, where a spring and brush are provided and first strip is arranged for sliding attachment to another strip.
[0008] A need exists for a weather sealing device which is economical to produce and assemble, and which can be easily installed on a frame of a door, such as, for example, a garage door, and replaced when necessary (i.e., when damaged).
SUMMARY OF THE INVENTION
[0009] A sealing device for a door, and in particular for a garage door, for sealing the door and frame to facilitate the exclusion of elements, such as, for example, draughts, wind, rain, snow, insects, and the like. An improved weather strip sealing device is provided which affords a pleasing appearance, is easy to install, and can be removed and replaced when necessary.
[0010] A first part or base is mounted to a door frame in proximity to a garage door. A matingly configured second part is adapted to be connected to the first part. Preferably, the second part carries a flexible portion which is provided to engage with the garage door to maintain a seal.
[0011] An attachment mechanism is provided to connect the first part with the second part, so that the first part can be installed prior to connecting the second part with the first part. Preferably, the first part can be positioned for mounting on a door frame, and once positioned, the installer will have more than one choice of attachment locations along the first part at which to attach the first part to the frame. That is, if for example, screws or nails are used, more than one nailing (or screw) spot along the length of the first part is provided. This facilitates mounting and attachment, in particular, where a single choice of nailing would otherwise cause the location of the nail to be between two pieces of wood or another undesirable location.
[0012] A connecting mechanism is provided to facilitate the connection of the second part with the first part. Once the first part is installed on a frame, the second part, preferably, is press fit over the first part and snapped into engagement therewith. Suitable connecting elements of the first part engage with connecting elements of the second part. Similarly, the second part can be removed from the first part when necessary.
[0013] Preferably, the first part and second part are comprised of material which is resistant to whether and elements which are to be encountered, such as, for example, acid rain, cold, heat, water, and the like. The first and second parts, preferably, are also flexible so that they can be snapped together, and readily separated, if desired. An additional benefit to providing a flexible material composition is that in the unfortunate event that the sealing device is used for sealing around the perimeter of a garage door, and is accidentally hit by a car exiting or entering the garage, the second part can detach, thereby possibly minimizing further damage to the garage frame, as well as the vehicle. Similarly, if the second part is damaged, but the first part is not, a new second part can be installed on the first part.
[0014] Similarly, if a new garage door is installed, a second part can be replaced with one which is compatible with the new door. For example, if a stainable garage door is used, and the second part was painted, the painted second part can be replaced with a stainable second part, which can be stained to match the door.
[0015] An object of the present invention is to provide a novel weather strip device for sealing around the perimeter of a door.
[0016] Another object of the present invention is to provide a novel weather strip device which can be stained or painted to match existing trim or molding pieces.
[0017] Another object of the present invention is to provide a novel weather strip device which can be attached to a mounting surface with fasteners, and which when installed hides the fasteners from view.
[0018] Another object of the present invention is to provide a novel weather strip device having an appearance of wood.
[0019] Another object of the present invention is to provide a novel weather strip device which has a first part which is mountable to a mounting surface and a second part which may be snap-fit into position over the first part.
[0020] Another object of the present invention is to provide a novel weather strip device which has multiple mounting locations for facilitating attachment of the device to a mounting surface.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0021] FIG. 1 is a front elevation view of a weather strip device constructed in accordance with the invention.
[0022] FIG. 2 is a front elevation view showing the base member of the device separately from the other components.
[0023] FIG. 3 is a top plan view of the base member shown in FIG. 2 .
[0024] FIG. 4 is a top plan view of the weather strip device of FIG. 1 shown installed in a door frame with a garage door and a door jamb illustrating an environment of use.
[0025] FIG. 5 is a side elevation view showing the weather strip device of FIG. 1 installed on a header of a door frame and in an environment with a garage door.
[0026] FIG. 6 is a front perspective view showing a garage door installed in a frame with the weather strip device of FIG. 1 installed around the perimeter of the door.
[0027] FIG. 6 a is an enlarged view taken of the encircled area of FIG. 6 .
[0028] FIG. 7 is a front elevation view showing an alternate embodiment of a weather strip device in an exploded view illustrating the cover member and base member.
[0029] FIG. 8 is an enlarged partial view of the of the cover member of FIG. 7 taken in the circle 8 of FIG. 7 to illustrate the left side wall.
[0030] FIG. 9 is an enlarged partial view of the of the cover member of FIG. 7 taken in the circle 9 of FIG. 7 to illustrate the right side wall.
[0031] FIG. 10 is an enlarged partial view of the base member of FIG. 7 taken in the circle 10 of FIG. 7 to illustrate the left side wall.
[0032] FIG. 11 is a perspective view of the base member of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Referring to the drawing figures, there is illustrated a weather strip 10 constructed in accordance with the present invention. The weather strip 10 comprises a first part or base member 11 which is adapted to be mounted on a door frame and a second part 12 which is adapted to be removably connected with said base member 11 . The base member 11 is illustrated best in FIG. 2 having a rear wall 13 and mounting means for attaching the base member to a mounting surface. In accordance with a preferred embodiment of the invention, the mounting means may comprise a plurality of apertures 15 , 16 disposed in the base member rear wall 13 . Suitable fastening members, such as screws, nails, bolts, or the like, may be used to attach the base member 11 to a supporting surface.
[0034] As shown in FIGS. 4 and 5 , the fastening members are illustrated as nails 17 , 18 which are inserted into the base member apertures, respectively 15 and 16 , and are driven into the doorjamb 101 . The apertures 15 , 16 preferably are arranged to provide at least two locations along the vertical span of the base member 11 for facilitating the attachment of the base member 11 to a door frame. Referring to FIG. 2 , the apertures 15 , 16 are arranged in at least two longitudinal spaced apart courses, a first course 19 being represented by those apertures designated 15 , and a second course 20 being represented by those apertures designated 16 . The first course 19 and second course 20 provide alternate fastening locations so that in the event that one of the fastening locations is not feasible, that is due to a wood joint, seam, knot, or other impediment, there are alternate locations at which to fasten the base member 11 to preserve its location proximate to a door, such as, for example, the garage door 100 illustrated in FIGS. 4 and 5 . Alternately, while shown secured with nails 17 , 18 in both courses of the apertures 15 , 16 , alternate nailing utilizing only some of the apertures 15 , 16 , or one of the courses 19 or 20 , may be done to attach the base member 11 to a door jamb.
[0035] The second part 12 connects with the base member 11 , and can be removed and replaced from the base member 11 as the user elects. Connecting means is provided for connecting the second part 12 with the base member 11 . Connecting means preferably comprises a first connecting element disposed on the base member 11 which may be connected to the second part, with the first connecting element being configured for releasable securing with said second connecting element.
[0036] In accordance with the preferred embodiment, connecting means is provided for connecting the second part 12 with the base member 11 . The base member 11 has a first side wall 22 and a second side wall 23 each having a first end 24 , 25 , respectively, which is connected to the base member rear wall 13 , and a second end 26 , 27 , respectively which is located a predetermined distance from the rear wall 13 . The side walls 22 , 23 carry a first connecting means thereon for connecting with the second part 12 . The first connecting means is shown comprising longitudinal ribs 28 , 29 provided on the first side wall 22 and longitudinal ribs 30 , 31 on the second side wall 23 . A recess 32 is shown formed between the longitudinal ribs 28 , 29 , and a recess 33 between ribs 30 , 31 .
[0037] Second connecting means is provided on the second part 12 for connecting with the base member 11 . As illustrated in FIGS. 4 and 5 , the first connecting means and second connecting means are matingly associated with each other to secure with each other when engaged. The second part 12 preferably is constructed having a front face 40 , a first side wall 41 and a second side wall 42 . The first side wall 41 is shown having a first end 43 respectively, which is connected to the front face 40 , and a second end 44 which is located a predetermined distance from the front face 40 . Similarly, the second side wall 42 is shown having a first end 45 connected to the front face 40 , and a second end 46 located at a predetermined distance from the front face 40 . The side walls 41 , 42 form with said face 40 a substantially u-shaped channel 47 which is configured to fit over the base member 11 , as illustrated in FIG. 4 . The second connecting means provided on the second part 12 is illustrated comprising longitudinal ribs 50 , 51 disposed on the second part first side wall 41 , and longitudinal ribs 52 , 53 disposed on the second side wall 42 . Grooves 54 , 55 , and 56 , 57 are shown formed in connection with the ribs 50 , 51 , and 52 , 53 .
[0038] The second part 12 has a sealing element 60 which preferably is comprised of a flexible material. The sealing element 60 preferably is provided on a side wall of the second part 12 , such as the second part second side wall 42 , illustrated in FIGS. 4 and 5 . The sealing element 60 is disposed to engage with a door, such as for example, the garage door 100 shown in FIGS. 4, 5 and 6 . Preferably, the sealing element 60 is constructed from a flexible material which can withstand extreme weather conditions, and temperature changes. The base member 11 is installed on the door jamb 102 proximate the door 100 so that when the second part 12 is connected to the base member 11 , the sealing element 60 preferably engages the door 100 .
[0039] While shown carried by the second part 12 , the sealing element 60 , alternately, may be carried by the base member 11 , although not illustrated.
[0040] The weather strip 10 is installed by aligning the base member 11 along the door jamb 102 and mounting the base member 11 to the doorjamb 102 with a fastening member. The second part 12 is connected, preferably by press-fit, or snapping into position over, the base member 11 . It is preferred that the second part 12 have side walls which are flexible so that the side walls 41 , 42 can be flexed to fit over the side walls 22 , 23 , respectively of the base member 11 to align the grooves 32 , 33 of the base member 11 with the respective corresponding ribs 50 , 51 and 52 , 53 of the second part 12 , as shown in FIG. 4 .
[0041] Preferably, the second part 12 is constructed to comprise a living spring with the first wall 41 and second wall 42 being provided as spring members. In addition, the face 40 of the second part 12 can also be provided as a living spring to work with the first wall 41 and second wall 42 . The walls 41 and 42 are biased to a rest position shown in FIG. 5 . When the second part 12 is installed on the first part 11 by positioning it over the first part 11 and pressing it thereon, the walls 41 and 42 engage the walls 22 , 23 of the base member 11 and are moved outwardly, and upon being aligned for connection, as shown in FIG. 4 , the natural bias of the living spring holds the second part 12 on the first member 11 . It will be understood that while the living spring is described in relation to the second part 12 , the base member 11 can also be constructed as a living spring. Alternately, one or the other, or both, the base member 11 and the second part 12 can be constructed as a living spring.
[0042] Preferably, as shown, the mounting surface may comprise a door frame, header, jamb, wall or other surface surrounding a door panel. Referring to FIG. 6 , a door entry way is illustrated in connection with a garage door 100 , and is surrounded by a left side doorjamb 102 , a right side doorjamb 103 and a header 104 . The weather strip 10 is preferably attached to each the left side doorjamb 102 , the right side doorjamb 103 , and the header 104 in order to provide a seal with the door 100 . For purposes of illustrating the invention, the weather strip 10 is shown in FIGS. 4 and 5 installed in connection with a garage door 100 .
[0043] The second part 12 may be removed as desired by the user. For example, if during use the second part 12 should become damaged, then the base member 11 can remain installed, and the second part 12 removed and replaced with a new or an undamaged second part.
[0044] Preferably, the base member 11 is comprised of a material which is strong and resistant to extreme weather conditions, as well as changes in weather conditions. Suitable materials include aluminum, plastic, vinyl and fiberglass. Similarly the second part 12 is likewise configured from a material which is strong, resistant to extreme weather conditions, as well as changes in weather conditions, and which can include such materials, for example, as aluminum, plastic, vinyl and fiberglass.
[0045] In accordance with a preferred embodiment of the invention, the second part 12 can comprise a stainable, paintable material, such as fiberglass. This facilitates matching of the weather strip 10 appearance with the garage door 100 , trim, or other surrounding elements.
[0046] Although shown with two ribs 28 , 29 , a single rib, or multiple ribs may be employed consistent with the principles of the invention disclosed herein. Alternately, or in addition thereto, it will be understood that the ribs, while disclosed as being longitudinally provided over the length of the base member 11 can be provided as segments which are non-continuous over the length of the base member 11 .
[0047] Referring to FIGS. 7-11 , there is illustrated an alternate embodiment of a weather strip 110 constructed in accordance with the present invention. The weather strip 110 , like the weather strip 10 , has a first part or base member 111 which is adapted to be mounted on a door frame and a second part 112 which is adapted to be removably connected with the base member 111 . Connecting means preferably comprises a first connecting element 128 disposed on the base member 111 which may be connected to the second part 112 , with the first connecting element 128 being configured for releasable securing with a second connecting element 154 . In accordance with the embodiment illustrated in FIGS. 7-11 , connecting means is provided for connecting the second part 112 with the base member 111 . The base member 111 has a first side wall 122 and a second side wall 123 each having a first end 124 , 125 , respectively, which is connected to the base member rear wall 113 , and a second end 126 , 127 , respectively, which is located a predetermined distance from the rear wall 113 . The side walls 122 , 123 are provided with first connecting means thereon for connecting with the second part 112 . The first connecting means is shown comprising a pair of first connecting elements 128 , 129 which are configured for releasable securing with second connecting means of the second part 112 . The second connecting means preferably comprises second connecting elements, such as, for example, the recesses 154 , 155 which are configured to receive the respective first connecting elements 128 , 129 . The first connecting element 128 preferably may comprise a flange 128 a, and may be continuous along the first side wall 122 of the base member 111 .
[0048] Preferably, a plurality of first connecting elements 128 , 129 may be provided. In the embodiment illustrated in FIG. 7 , two first connecting elements 128 , 129 are provided. The first connecting elements 128 , 129 are each configured, respectively, as a flange portion 128 a, 129 a disposed along the outer surface of the side wall 122 . The second side wall 123 of the base member 111 also has first connecting elements 131 , 132 which are each shown configured as flanges 131 a, 132 a, respectively. Referring to FIG. 11 , there is illustrated a perspective view of the base member 111 of the weather strip 110 to further illustrate a preferred embodiment where the first connecting elements are configured as fingers or flanges, such as the flanges 128 a, 129 a, 131 a, 132 a.
[0049] The weather strip first part or base member 111 preferably may be configured as an elongate member having a mounting surface or rear wall 113 and pair of spaced apart side walls 122 , 123 . Each side wall 122 , 123 preferably has a first end 124 , 125 , respectively, which is connected to the mounting surface 113 . Each side wall 122 , 123 protrudes outwardly from said mounting surface 113 , and preferably has an outer surface on which the respective first connecting elements 128 , 129 and 131 , 132 , may be disposed.
[0050] The flanges 128 a, 129 a, 131 a, 132 a preferably may be angularly configured. Flanges 128 a and 129 a are illustrated in FIG. 10 . The flange 128 a may have a configuration with an angled or sloped surface. The flange 128 a is shown having a locking surface 128 b which is provided to engage with the first recess 154 of the second member 112 . The sloped surface of the flange 128 a facilitates camming of the second part 112 onto the base 111 . The flange 129 a has a locking surface 129 b and is spaced apart from the flange 128 a to form a recess 129 c. The recess 129 c preferably has an angular dimension as indicated by an angle α° for facilitating the connection between the first connecting means and second connecting means. ( FIG. 10 ). As illustrated in FIG. 10 , a preferred angular dimension α° is less than about 90° and may be about 60°. Similarly, the flanges 131 a, 132 a may be provided in an angular configuration.
[0051] The second part 112 preferably has matingly associated recesses, including a first recess 154 and a second recess 155 , which preferably correspond with the configuration of the first part flanges 128 a and 129 a, respectively. Connecting means is provided on each side wall 122 , 123 of the first part or base 111 . Preferably, the side wall 123 of the base 111 opposite the side wall 122 , and the side wall 141 of the second part 112 opposite the first side wall 142 have connecting means. Connecting means of the first part side wall 123 may be configured similar to the connecting means described in connection with the first base side wall 122 . The second part side wall 141 may have connecting means configured similar to the first recess 154 and second recess 155 of the side wall 142 . As illustrated in FIG. 7 , the second part side wall 141 has a first recess 156 , and a second recess 157 which are matingly configured to correspond, respectively, with the flanges 131 a, 132 a provided on the second side wall 123 of the base member 111 . Preferably the recesses 154 , 155 and 156 , 157 are angularly configured as shown in FIG. 9 . The angle α° preferably is configured to correspond to the angle α° of the first part flanges 128 a, 129 a.
[0052] The side wall 142 has a groove 182 in which a sealing member 160 is carried.
[0053] Preferably, a leg of the second part 112 or the base member 111 is flexible to an extent which permits snap fit installation of the second part 112 together with the base member 111 . The second part 112 may be connected to the base 111 by press fit installation. Alternately, the second part 112 may be fitted over one of the first part side walls 122 , 123 so that the connecting means (such as for example flanges 128 a, 129 a and recesses 154 , 155 ) on one side of the weather strip 110 engage, and the connecting means (flanges 131 a, 132 a and recesses 156 , 157 ) on the other side of the weather strip 110 are then snap fit into engagement. This may be done preferably by engaging one of the side walls 141 , 142 of the second part 112 with the first part 111 , and swinging the second part 112 over the first part 111 until the other of the second part side walls 141 , 142 engages the first part 111 , and the connecting means are secured.
[0054] The weather strip 110 preferably has mounting means for mounting the device 110 to a frame. The weather strip, device may be installed to a surface in the same manner as described in connection with the weather strip 10 illustrated in FIGS. 1-6 a. As illustrated in FIGS. 7, 10 and 11 , the base member 111 preferably has a plurality of apertures 180 formed in the rear wall 113 for accommodating mounting hardware, such as for example a screw, nail or other securing element. Preferably, the apertures 180 may have an elliptical or elongated configuration to permit mounting of the base member 111 along different locations on the mounting surface. The elongated configuration of the apertures 180 facilitates lateral adjustment of the weather strip 110 , which may be important when installing the weather strip 110 , or over time, should the weather strip 110 require repositioning. In addition, the weather strip 10 described and illustrated herein, also be provided with similar mounting means, which may comprise elongated apertures.
[0055] Although shown with two flange portions 128 a, 129 a, a single flange, or multiple flanges may be employed consistent with the principles of the invention disclosed herein. Alternately, or in addition thereto, it will be understood that the flanges, while disclosed as being longitudinally provided over the length of the base member 111 can be provided as segments which are non-continuous over the length of the base member 111 .
[0056] The weather strip devices according to the present invention may be provided in different finishes so that the user may select a particular finish to match or coordinate with the surrounding structure, such as door trim, door panels, and the like. For example, the weather strip may be gray to match gray siding on a house or may be a stained fiberglass to match a redwood door. These and other colors and finishes may be utilized in connection with the weather strip invention.
|
A sealing device for a door, and in particular for a garage door, for sealing the door and frame to facilitate the exclusion of elements, such as, for example, draughts, wind, rain, snow, insects, and the like, with a first part or base provided for mounting to a supporting surface, and a second part constructed to attach to the first part, the second part carrying a sealing element.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/646,920 filed Jan. 25, 2005, which is incorporated by reference herein in its entirety.
GRANT REFERENCE
[0002] This research was federally funded under Defense Microelectronics Activity (DMA), Department of Defense, Contract No. 1-194003-04-2-0404. The government may have certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] A wide variety of toxins exist in nature and they can also be synthetically produced. They vary in their structural complexity, ranging from formic acid produced by ants to protein toxins produced by several bacteria. Neurotoxins are among the most poisonous and fastest acting toxins. They specifically target the nervous system of animals, including humans, by interfering with the transmission of nervous signals. Neurotoxins are generally more lethal than toxins produced by microbes, and can cause incapacitation or death of the affected individual within minutes of exposure. As a result, neurotoxins have been and will continue to be significant potential candidates for weaponization. Examples of weaponized neurotoxins include Tabun (GA), Sarin (GB), Soman (GD), Cyclosarin (GF), DFP, DMMP, and VX, among others.
[0004] Each of these listed neurotoxins, and others, are organophosphates. Their neurotoxic activity arises from their ability to inhibit the functionality of acetylcholine esterase (AChE). Under normal conditions, AChE catalyzes the hydrolysis of the neurotransmitter acetylcholine (ACh) to acetic acid and choline. This reaction allows cholinergic neurons to return to their resting state after activation. In the presence of organophosphates, however, AChE is inhibited and neurons are unable to return to their resting state. In low doses, this results in eye watering and excessive salivation, and in higher doses, individuals are afflicted with various conditions, including salivation, lacrimation, urination, defecation, gastro intestinal upset, and emesis. When dosage is high enough, exposure to these compounds can also result in death. It is these properties of organophosphates that make them particularly suited for use not only as pesticides, but also as potential chemical warfare agents.
[0005] Because of this potential use of organophosphates as weapons and the speed with which they attack the human body after exposure, there is a critical need for an efficient method to quickly and accurately detect these highly toxic compounds. While there have been several developments in the past decade for detection of organophosphates, including colorimetric detection methods, surface acoustic wave (SAW) devices, enzymatic assays, and interferometry, each of these has at least one disadvantage. The limitations of these existing methods include slow response time, lack of specificity, low sensitivity, operational complexity or non-portability. For example, two major approaches that have received extensive attention are immuno-based assays and DNA sequencing schemes. However, immuno-based assays are difficult to implement outside of the laboratory because of the instability of the antibodies involved and the necessity of including unstable reagents in the assay. And DNA sequencing techniques are time and instrument-intensive, so therefore they cannot meet the requirements for practical field use. Additionally, both approaches require extensive operator training to be properly implemented.
[0006] Another common approach to sensing the presence of organophosphates is to rely upon an immobilized AChE detector coupled to a transducer such as Ph electrodes, fiber optics, and piezo electric crystals. This approach, however, is hampered by several limitations. For example, immobilized enzymes are sensitive and detect a broad spectrum of AChE inhibitors. Because of this broad range sensitivity, they lack selectivity and are prone to false positive alerts, particularly when exposed to choline mimics.
[0007] In addition to detection of organophosphates, there is a need for any sensor to convert a detector's chemical, mechanical, or optical change into a measurable signal when the organophosphates are present. Many different types of sensors are known in the art. For example, chemical sensors often detect conductivity changes, amperometric changes, or potentiometric changes. Optical sensors detect changes in emission or absorption. Mechanical sensors can detect changes in mechanical properties or impedance. However, none of the known sensors are or can be linked to a detection sensitive material which provides both quickness of alert and accuracy of detection.
[0008] As can be seen from the foregoing, there is a need in the art for development of a way to quickly detect the presence of neurotoxins in such a way that can be utilized in non-laboratory applications, by minimally trained personnel, with a low incidence of false positive alerts.
[0009] It is therefore an object of the present invention to provide a neurotoxin-sensitive compound that can selectively detect various organophosphates agents over a range of concentrations and conditions.
[0010] A further object of this invention is to provide a compound for use in optoelectronic sensors to detect organophosphates agents.
[0011] It is another object of this invention to provide a polymer capable of use in optoelectric sensors for detection of organophosphates agents.
[0012] Another object of this invention is to provide a method for detecting organophosphate agents using lumiphoric compounds.
[0013] These and other objects of the present invention will become apparent from the description of the invention that follows.
BRIEF SUMMARY OF THE INVENTION
[0014] The invention described herein provides a practical method for using organic compounds and/or polymers to detect various bioactive and other types of agents that include halogen or methoxy groups, including organophosphates, neurotoxins, pesticides, metal ions, and combinations thereof. When the detection chromophore or polymer of the invention come in contact with the compound to be detected, the detection compound reacts with a compound to be detected, thereby changing the fluorescence properties of the detection compound. This change in fluorescence can then be measured and indicates the presence of the compound to be detected. The chromophore or polymer may be used in a variety of sensors, including optical electronic sensors, biosensors, and surface acoustic wave sensors for detection of the various organophosphate and other compounds that may be detected.
[0015] Transition metal complexes that are luminescent in room-temperature solution have been used in a variety of chemical and biochemical applications. Many of these applications require that the metal lumiphore be functionalized so that it can be appended to a molecule or macromolecule of interest or activated by chemical reaction. Such functionalized lumiphores have been used in electron-transfer studies, in the design of new biosensors, and in the formulation of emissive paints.
[0016] In the present invention, the binding capability of pyrazines and aminopyrazines to bind metals and other organic and biomolecules is utilized to synthesize new organic or polymeric materials whose fluorescence properties change when coming into contact with appropriate analytes.
[0017] This change in fluorescence characteristics can be used to produce a sensor to assist in the detection of these various compounds. These multi valiant interactions produce a distance-dependent fluorescence energy transfer, and can be used in a regent-free, highly sensitive, and specific sensing technology for detection of these toxins.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a graph showing the emission spectra of the chromophore of the present invention with dimethylchlorophosphonate (DMCP).
[0019] FIG. 2 illustrates the UV-Vis absorption and emission spectra of polyparaphenylene derivatives having amino pyrazine units as described in Example 1.
[0020] FIG. 3 illustrates the intensity of fluorescence of polymer and polymer+dimethylchlorophosphonate (DMCP).
[0021] FIG. 4 illustrates the intensity of fluorescence of polymer and polymer+dimethyl methylphosphonate (DMMP).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] In its broadest sense, the invention comprises the use of a polymer or chromophore with luminescent properties that are either enabled (in the case of the chromophore) or disabled (in the case of the polymer) in the presence of a compound to be detected, and methods of using said polymer and/or chromophore to detect such compounds. In addition, the invention includes a method of producing the polymer and chromophore.
[0023] In a preferred embodiment, a polymer is produced that ceases to fluoresce when contacted with an organophosphate, neurotoxin, pesticide, metal ion, biological agent (or combinations thereof) or other types of compounds containing at least one halogenated group. Specific examples of halogenated neurotoxins include sarin, soman, GF, and DFP. While the present invention specifically refers to the use of detection agents for use in detecting neurotoxins, it is to be understood that the present invention is useful for detection of numerous compounds that contain one or more of the functional groups of interest.
[0024] In contrast to the polymer, the chromophore of the present invention fluoresces when contacted with an organophosphate, neurotoxin, pesticide, metal ion, biological and/or other types of compounds containing either a halogenated or methoxy-functional group.
[0025] The respective modes of detection of the polymer and the chromophore allow an effective dual means of detecting and identifying various compounds containing a halogenated and/or methoxy group. For instance, the chromophore can be used to generally detect the presence of a neurotoxin. Once a neurotoxin is detected, the polymer can be used to more specifically identify whether the neurotoxin is one containing a halogenated group. Alternatively, the polymer and chromophore can also be used individually to detect the presence of various halogenated and/or methoxylated neurotoxins.
[0026] The backbone of the polymer is generally made up of some combination of at least one of aminopyrazines, pyrazine, aminopyridine, or any amine containing an aromatic moiety; one or more of thiophene, pyridine, bipyridine, quinoline, isoquinoline, paraphenylene, hydroxyl paraphenylene, a phenyl group, or any hetero aromatic system. The backbone has a total number of between 1 and 100 units, with about 5-20 being preferred. The backbone preferably consists of pyrazine, aminopyridine, or aminopyrazine, with aminopyrazine being most preferred.
[0027] Preferred polymers of the present invention have the following general formula:
[0000]
[0000] wherein R 1 is H, alkyl, cycloalkyl, benzyl, or any aromatic, heteroaromatic, or heterocyclic group; and n is an integer between 1 and 100; and R 2 is a C 6 -C 15 alkyl chain. Again, n is preferably 5-20.
[0028] Most preferred polymers of this invention have the following general formula:
[0000]
[0000] wherein R 1 is H, alkyl, cycloalkyl, benzyl, or any aromatic, heteroaromatic, or heterocyclic group; and n is an integer between 1 and 100, with 5-20 being preferred.
[0029] The chromophore of the present invention has the following general formula:
[0000]
[0000] wherein R is H, NH 2 , an aliphatic chain, or an aromatic group. The aliphatic chain is preferably C 1 -C 8 .
[0030] Preferred chromophores of the invention have one of the following formulas shown below:
[0000]
[0031] The chromophore and polymer are generally prepared by Suzuki coupling reactions. Such reactions are well known and understood in the art. In general, an organoborane is reacted with an organic halide in an organic solvent, such as tetrahydrofuran (THF) and ethers. This reaction preferably occurs in a nitrogen atmosphere with vigorous stirring at a temperature between 90-110° C. However, other temperatures, atmospheres, and reaction conditions are also appropriate, as would be understood to persons skilled in the art. The use of a palladium catalyst is also preferred. Once the reaction is complete, the organic phase is separated and the polymer precipitated therefrom. The precipitated polymer is then separated and dried using conventional means or can be retained in solution.
[0032] In the absence of neurotoxins, the polymer fluoresces in the presence of ultraviolet light. However, upon contact with the halogenated phosphate esters of neurotoxins, the polymer quenches the fluorescence of the neurotoxin, thereby facilitating its detection. This fluorescence quenching is the result of the NH 2 group of the conducting polymer hydrolyzing the halogenated phosphate ester and releasing acid which in turn oxidizes the polymer.
[0033] The detection of the organophosphate molecule by the change in fluorescence characteristics of the polymer occurs quite rapidly, typically in less than three seconds. Given this fast response time, the polymer is particularly suited for use in optoelectronic sensors.
[0034] In addition to the above-described polymer, a non-polymeric chromophore may also be used to detect the presence of the organophosphates and other biological agents already described above. The chromophore has the reverse fluorescence characteristics as the polymer, meaning that in the absence of organophosphate molecules, the chromophore does not fluoresce in the presence of ultraviolet light. The chromophore gains its fluorescence under ultraviolet light when a neurotoxin containing either a methoxy or halogenated group is present. The fluorescence is the result of the reaction of the OH of the chromophore with these functional groups.
[0035] The chromophore and polymer have different mechanisms of action to detect the presence of organophosphates or other compounds. Generally, the polymer hydrolyzes the halogenated phosphate ester of the organophosphate molecule and releases acid, which in turn oxidizes the polymer. This leads to formation of imine form of the polymer, which is not fluorescent after binding with the organophosphate. This imine form is depicted below:
[0000]
[0000] Cyclic voltammetry shows that the polymer is oxidized in two steps, and the EIS measurement shows an increase in resistivity with oxidation. It is the increase in resistivity that explains the quenching of the fluorescence in response to the presence of organophosphate or other molecules capable of detection. FIG. 3 illustrates the intensity of fluorescence of unbound polymer compared to polymer bound to DMCP. FIG. 4 illustrates that polymer bound to dimethylmethylchlorophosphonate (a non-halogenated neurotoxin) has the same intensity of fluorescence as unbound polymer.
[0036] As noted, the chromophore detects the presence of organophosphates or other detectable molecules by interaction between the hydroxyl group and the methoxy or halogenated group of the neurotoxin molecule. This leads to a cyclization reaction which in turn produces the fluorescent molecule depicted below. The overall reaction is also shown:
[0000]
[0000] where A − is P O 2 (OCH 3 ) 2 − . FIG. 1 is a graph showing the emission spectra of the most preferred chromophore of the present invention (as shown above) with dimethylchlorophosphonate (DMCP).
[0037] Based on the above-described mechanisms of action, the chromophore and polymer described are able to detect a wide variety of compounds. The chromophore can detect any neurotoxin having a methoxy or halogenated group, and the polymer will detect halogenated neurotoxins specifically. Detectable compounds include organophosphates having the requisite halogen or methoxy group, such as sarin, cyclosarin, soman, tabun, diisopropylfluorophosphate, diethylchlorophosphate, VE, VG, VM, VX, metrifionate, pyridostigmine, and physostigmine; explosives such as plastic explosive or trinitrotoluene; and metal ions, such as iron, cobalt, nickel, copper, a transition metal ion, or a main group metal ion.
[0038] For years military force have used detection devices to identify these same materials but even today's best detection measures may require minutes for the user to receive an accurate alert to a potential hazard. Some detectors are quicker but they also provide more false alerts.
[0039] The polymer and chromophore of the present invention can accurately identify trace amounts of poisons or explosives having halogen and/or methoxy functional groups in seconds. These detection molecules can detect leaks in shipping containers of certain industrial chemicals, detect certain explosive compounds and detect an entire family of neurotoxins. In addition to giving advanced notice to the presence of hazards, the detection molecules can be used to authenticate the elimination of chemical agents or toxic substances during an investigation or clean-up operation.
[0040] The polymers of the present invention notify users via multiple feedback methods. They can be set to fluoresce in ultraviolet light yet remain clear in visible light. When in this mode, the fluorescence will quench as a toxic substance or explosive compound comes into contact it. Alternatively, the chromophore can provide no initial ultraviolet fluorescence, but fluoresces upon exposure to a toxic substance or explosive compounds.
[0041] The detection molecules of this invention also have the unique property of providing enough electrical activity upon coming into contact with a hazardous substance so that it can be integrated into many of today's existing electrical sensors.
[0042] Rapid alert notification to the presence of a fast acting neurotoxin is extremely important. Many chemical agents cause injury or death in less than a minute. Speed is also essential when multiple yet rapid and economical detections must be made (for example, hand screening of luggage). The detection molecules of the present invention provide accurate detection within 2 to 3 seconds of contact with a target substance as compared to minutes with similar technologies. These unique molecules are designed to detect trace amounts of:
the entire family of halogenated chemical compounds with very high selectivity; the chemical warfare agents VX, GF, GB (Sarin), GD, (Soman) and GA (Tabun); explosives (various plastic explosives and TNT); and pesticides (organo-phosphonates like DFP and DMMP).
[0047] The detection molecules need only be applied in strengths ranging from parts-per-millions to part-per-billions. Further, under certain circumstances, the molecules can be reconditioned for repetitive use.
[0048] The detection molecules of the instant invention can be applied separately or together, and as an individual coating or mixed with other coatings. They can be sprayed or painted on to a surface, and can be applied to such simple materials a tape or cloth swabs, or applied to much more complex devices such as electronic sensors or electronic noses. Sensors incorporating either or both of the chromophore and/or polymer can be easily used in any location in which fast detection of neurotoxins is desired. Examples might include potential targets for terrorist attacks, such as subways, airports, aircraft, or government buildings. The basic performance and functionality of these molecules in detecting neurotoxins have been verified with fluorescence measurements, impedance testing and cyclic voltammetry.
[0049] In addition to being used to detect neurotoxins in the context of terrorism or chemical warfare, the polymer and chromophore described can also be used to detect the presence of organophosphates in the context of medical diagnosis or treatment monitoring. In fact, the polymer and chromophore may be used to detect neurotoxins in virtually any desired application.
[0050] The following examples are offered to illustrate but not limit the invention. Thus, they are presented with the understanding that various formulation modifications as well as method of delivery modifications may be made and still be within the spirit of the invention.
EXAMPLE 1
Preparation and Properties of a Preferred Polymer
[0051] A preferred polymer of the present invention was prepared by the following method:
a) 2,5-Dibromo-4-dodecyloxy phenol
[0052] 2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH 2 Cl 2 :hexanes, 4:6) to get the pure product in 60% yield.
[0053] 1 H NMR, (CDCl 3 , δ ppm): 7.25 (s, 1H,), 6.97 (s, 1H), 5.16 (s, 1H), 3.92 (t, 2H), 1.62 (q, 2H), 1.4 (m, 18H); 0.88 (t, 3H). 1 H NMR (CDCl 3 , δ ppm): 7.25 (s, 1H), 6.97 (s, 1H), 3.92 (t, 2H), 1.80 (q, 2H), 1.4 (m, 18H); 0.87 (t, 3H). 13 C NMR (CDCl 3 , δ ppm): 149.95, 146.64, 120.16, 116.49, 112.34, 108.26, 70.25, 31.81, 29.55, 29.47, 29.26, 29.20, 28.97, 25.82, 22.60, 14.04.
b) 2,5-Dibromo-1-benzyloxy-4-dodecyloxy benzene
[0054] Benzyl bromide (3.8 ml, 0.031 mol) was added drop wise to a stirred solution of 2,5-dibromo-4-dodecyloxy phenol (a) (6.95 g, 0.015 mol) and anhydrous K 2 CO 3 (3.28 g, 0.023 mol) in 700 ml of absolute ethanol at 40-50° C. The reaction mixture was stirred for 10 h at 50° C., progress of the reaction was monitored using TLC, cooled to RT and evaporated to remove the solvent. An equal volume of distilled water was added to the residue and the mixture was stirred for one hour at 0° C. The resulting precipitate was collected by filtration, washed with water, and dried in vacuum. Recrystallization was done in methanol to get 80% yield.
[0055] 1 H NMR (CDCl 3 , δ ppm): 7.46 (m, 5H), 7.21 (s, 1H), 7.15 (s, 1H), 5.11 (s, 2H), 3.99 (t, 2H), 1.85 (q, 2H), 1.32 (m, 18H), 0.95 (t, 3H). 13 C NMR (CDCl 3 , δ ppm): 150.51, 149.49, 136.16, 128.50, 128.10, 127.17, 119.32, 118.31, 111.53, 111.01, 71.99, 70.19, 31.83, 29.56, 25.84, 22.60, 14.02
c) 1-Benzyloxy-4-dodecylozyphenyl-2,5-bisboronic acid
[0056] 1.6 M Solution of butyl lithium in hexanes (55 ml, 0.088 mol) was added slowly to a solution of dibromide b (11.57 g, 0.022 mol) in a mixture of solvents diethyl ether (150 ml) and THF (150 ml) under nitrogen atmosphere at −78° C. The solution was warmed to RT and cooled again to −78° C. Triisopropyl borate (51 ml) was added drop wise within 2 h. After complete addition, the mixture was warmed to RT and stirred overnight. Water was added and the mixture stirred for 24 h. The crystalline mass was recovered by filtration. The product was re crystallized from acetone in 80% yield.
[0057] 1 H NMR (DMSO-d 6 , δ ppm): 7.80 (s, 2H), 7.75 (s, 2H), 7.46 (m, 5H), 7.29 (s, 1H), 7.17 (s, 1H), 5.11 (s, 2H), 3.99 (t, 2H), 1.73 (q, 2H), 1.24 (m, 18H), 0.85 (t, J=6 Hz, 3H). 13 C NMR (DMSO-d 6 , δ PPM): 157.00, 156.22, 137.16, 128.38, 127.77, 127.52, 118.28, 117.70, 70.05, 68.30, 31.2, 28.89, 25.38, 22.00, 13.87.
d) 1-Benzyloxy-4-dodecyloxy phenyl-2,5-bis(trimethylene boronate)
[0058] Diboronic acid c (8.2 g, 0.018 mol) and trimethylene glycol (5.2 in], 0.072 mol) were added to toluene (150 ml) at RT. Then the reaction mixture was refluxed for 3 h. The solvent was removed by rotovap. The residue was dissolved in CHCl 3 , dried over sodium sulfate and filtered. The solution was evaporated and the residue was re crystallized from hexanes. The recrystallized product was used without further purification for polymerization.
[0059] 1 H NMR (CDCl 3 , δ ppm): 7.35 (m, 5H), 5.05 (s, 2H), 4.16 (d, 8H), 3.85 (t, 3H), 2.02 (m, 4H), 1.57 (m, 2H), 1.27 (m, 18H), 0.88 (t, 3H). 13 C NMR (CDCl 3 , 6 ppm): 157.73, 156.92, 138.28, 128.06, 127.00, 120.42, 119.79, 71.70, 69.70, 61.91, 31.81, 29.55, 27.22, 25.98, 22.57, 14.01.
e) 2-Amino-3,5-dibromopyrazine
[0060] Under absence of light and at 0° C., N-bromosuccinimide (15.68 g, 88.1 mmol) was added to a solution of 2-aminopyrazine (4.19 g, 44.06 mmol) in dry dichloromethane (250 ml). The mixture was stirred for 20 h at 4° C. and then washed with four 40 ml portions of a saturated sodium carbonate solution in water. The organic layer was dried (MgSO 4 ) and evaporated under reduced pressure, affording the title compound as 12.8 g of a light brown solid. Column chromatography, using silica and a dichloromethane/ethyl acetate (3/1) mixture as the eluent, yielded pure 2-amino-3,5-dibromopyrazine as 5.00 g (65%) of a light yellow solid.
[0061] 1H-NMR (CDCl 3 , 400 Mhz): 8.09 (s, I H), 4.95 (211, NH) ppm. 13C-NMR (CDCl3): 153.5 (C-2), 144.3, 131.9, 126.8 ppm
f) Synthesis of Poly(p-phenylene)-co-amino pyrazine polymer
[0062] Diboronic ester d (0.97 g, 0.186 mmol) and dibromo aminopyrazine e (0.458, 0.186 mmol) were added to dry THF (10 ml) under nitrogen atmosphere. 2M Na 2 CO 3 (15 ml) was added to this followed by palladium catalyst tetrakis(triphenylphosphino)palladium (1.5 mol % with respect to monomer d). The mixture was then heated to 100° C. for 72 h in a flask with vigorous stirring. After the reaction, the organic phase was separated and the polymer precipitated from hexane. The precipitated polymer was separated and dried to yield 0.5 g of polymer (Yield=60%). GPC analysis showed a number average molecular weight of 5300.
[0063] This leads to production of the following preferred polymer:
[0000]
EXAMPLE 2
Preparation of a Preferred Chromophore
[0064] a) Benzyl bromide (7 ml, 0.05 mol) was added drop wise to a stirred solution 2 bromo phenethyl alcohol (10 g, 0.0496 mol) and anhydrous NaH (2.28 g, 0.05 mol) in 100 ml of dry THF at 40-50° C. The reaction mixture was stirred for 10 h at 50° C., progress of the reaction was monitored using TLC, cooled to RT and evaporated to remove the solvent. An equal volume of distilled water was added to the residue and the mixture was stirred for one hour at ambient. The organic layer was separated, dried and evaporated. To the resulting liquid 100 ml of 5% ethanolic solution of NaOH was added and refluxed for 3 hr. The resulting solution was evaporated and extracted with ether to give the benzyl protected phenethyl alcohol as a clear liquid at 80% yield.
[0065] 1H-NMR (CDCl3, 400 Mhz): 7.5 (d, 1H), 7.3 (m, 7H), 7.08 (d, 1H), 4.53 (s, 2H), 3.7 (t, 2H), 3.07 (t, 2H) ppm. 13C-NMR (CDCl3, 100 Mhz): 138.43, 132.96, 131.37, 129.01, 128.58, 128.20, 127.78, 127.76, 127.57, 124.87, 73.12, 69.56, 36.71 ppm.
[0066] b) 1.6 M Solution of butyl lithium in hexanes (66 ml, 0.1 mol) was added slowly to a solution of 2-bromo O-benzyl phenethyl alcohol (9.7 g, 0.033 mol) in a mixture of solvents diethyl ether (150 ml) and THF (150 ml) under nitrogen atmosphere at −78° C. The solution was warmed to RT and recooled to −78° C. Triisopropylborate (23.1 ml) was added drop wise within 2 h. After complete addition, the mixture was warmed to RT and stirred overnight. Water was added and the mixture stirred for 24 h. The organic phase was separated and column chromatography of the resulting viscous liquid using dichloromethane as the eluent gave the boronic acid as white crystalline solid in 65% yield.
[0067] 1H-NMR (CDCl3, 400 Mhz): 7.8 (d, 1H), 7.4 (t, 2H), 7.3 (m, 4H), 7.2 (d, 1H), 7.1 (d, 1H) 4.53 (s, 2H), 3.75 (t, 2H), 3.07 (t, 2H) ppm. 13C-NMR (CDCl3, 100 Mhz): 143.78, 136.79, 134.15, 130.44, 129.32, 128.69, 128.20, 127.95, 126.13, 73.74, 72.47, 36.89 ppm.
[0068] c) Under absence of light and at 0° C., N-bromosuccinimide (7.84 g, 44.05 mmol) was added to a solution of 2-aminopyrazine (4.19 g, 44.06 mmol) in dry dichloromethane (250 ml). The mixture was stirred for 20 h at 4° C. and then washed with four 40 ml portions of a saturated sodium carbonate solution in water. The organic layer was dried (MgSO 4 ) and evaporated under reduced pressure, affording the title compound as 5.90 g of a light brown solid. Column chromatography, using silica and a dichloromethane/ethyl acetate (3/1) mixture as the eluent, yielded pure 2-bromo-5-aminopyrazine as 5.00 g (65%) of a light yellow solid.
[0069] 1H-NMR (CDCl3, 400 Mhz): 8.09 (s, 1H, H-6), 7.77 (s, 1H, H-3), 4.65 (bs, 2H, NH) ppm. 13C-NMR (CDCl3, 100 Mhz): 153.5 (C-2), 144.3 (C-6), 131.9 (C-3), 126.8 (C-5) ppm.
[0070] d) The boronic acid (0.8 g, 3.26 mmol) and bromo pyrazine (0.56 g, 3.26 mmol) were added to dry toluene (20 ml) under nitrogen atmosphere. 2M Na 2 CO 3 (15 ml) was added to this followed by palladium catalyst tetrakis (triphenylphosphino) palladium (1.5 mol % with respect to boronic acid). The mixture was then heated to 80° C. for 48 h with vigorous stirring. The reaction mixture was evaporated, washed with water and the organic phase was separated. Column chromatography of the compound using 1:1 Ethyl Acetate/Hexane mixture gave 60% of the required product.
[0071] 1H-NMR (CDCl3, 400 Mhz): 8.15 (s, 1H), 8.01 (s, 1H), 7.25 (m, 9H), 4.58 (s, 2H, —NH), 4.6 (s, 2H), 3.6 (t, 2H), 3.01 (t, 2H) ppm. 13C-NMR (CDCl3, 100 Mhz): 152.95, 145.20, 141.98, 138.65, 137.71, 137.33, 131.28, 130.85, 130.10, 128.56, 127.80, 127.71, 126.73, 72.97, 71.20, 33.64.
[0072] e) The O-benzyl protected compound was dissolved in a mixture of dry THF (50 ml) and absolute ethanol (50 ml) at RT. 10% Pd/C (3 g) was added to the above solution. The mixture was flushed with nitrogen gas three times. Two to three drops of conc. HCl was added to enhance the debenzylation. The reaction was carried out at RT under positive pressure of hydrogen for 24 h with constant stirring. The reaction mixture was filtered through celite powder and the precipitate was washed with absolute ethanol. The filtrate was evaporated and dried in vacuum to yield the desired Chromophore at 50% yield.
[0073] IH-NMR (CDCl 3 , 400 Mhz): 8.19 (s, 1H), 8.06 (s, 1H), 7.30 (m, 4H), 4.78 (s, 2H, —NH), 3.6 (t, 2H), 3.05 (t, 2H) ppm. 13C-NMR (CDCl3, 100 Mhz): 153.08, 145.20, 141.98, 138.65, 137.71, 131.28, 130.85, 128.56, 126.73, 64.26, 33.64.
[0074] This yields the preferred chromophore below:
[0000]
[0075] Having described the invention with reference to particular compositions, theories of effectiveness, and the like, it will be apparent to those of skill in the art that it is not intended that the invention be limited by such illustrative embodiments or mechanisms, and that modifications can be made without departing from the scope or spirit of the invention, as defined by the appended claims. It is intended that all such obvious modifications and variations be included within the scope of the present invention as defined in the appended claims. The claims are meant to cover the claimed components and steps in any sequence which is effective to meet the objectives there intended, unless the context specifically indicates to the contrary.
|
Applicants have produced a chromophore and a polymer that are highly sensitive to the presence of various agents, including organophosphates, pesticides, neurotoxins, metal ions, some explosives, and biological toxins. The detection is accomplished by detecting a change in the fluorescence characteristics of the chromophore or polymer when in the presence of the agent to be detected. The chromophore and polymer may be incorporated into sensors of various types, and they are adaptable for potential field use in areas where detection of these types of agents is desired.
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to United States Provisional Patent Application entitled SUPPLEMENTAL SPINE FIXATION DEVICE AND METHOD, filed Jul. 18, 2001, Serial No. 60/306,262 and is a continuation-in-part application of U.S. patent application Ser. No. 09/842,819, filed Apr. 26, 2001 and is a continuation-in-part application of U.S. patent application Ser. No. 09/579,039, filed on May 26, 2000 and entitled SUPPLEMENTAL SPINE FIXATION DEVICE AND METHOD, which is a continuation-in-part of U.S. patent application Ser. No. 09/473,173 filed on Dec. 28, 1999 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,235,030 issued May 22, 2001, which is a continuation of U.S. patent application Ser. No. 09/179,570 filed on Oct. 27, 1998 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,048,342 issued Apr. 11, 2000, which is a continuation-in-part of U.S. patent application Ser. No. 09/175,645 filed on Oct. 20, 1998 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,068,630 issued May 30, 2000. All of the above applications and patents are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to supplemental spine fixation devices and methods which are used as an adjunct to a primary spine fusion method and/or device, such as by way of example only, an inter-body fusion device. The present invention is also directed to a method and apparatus for engaging adjacent spinous processes without the use of a primary spinal fusion method or device.
BACKGROUND
[0003] A common procedure for handling pain associated with degenerative spinal disk disease is the use of devices for fusing together two or more adjacent vertebral bodies. The procedure is known by a number of terms, one of which is inter-body fusion. Inter-body fusion can be accomplished through the use of a number of devices and methods known in the art. These include screw arrangements, solid bone implant methodologies, and fusion devices which include a cage or other mechanism which is packed with bone and/or bone growth inducing substances. All of the above are implanted between adjacent vertebral bodies in order to fuse the vertebral bodies together, alleviating associated pain.
[0004] Associated with such primary fusion devices and methods are supplemental devices which assist in the fusion process. These supplemental devices assist during the several month period when bone from the adjacent vertebral bodies is growing together through the primary fusion device in order to fuse the adjacent vertebral bodies. During this period it is advantageous to have the vertebral bodies held immobile with respect to each other so sufficient bone growth can be established.
[0005] Such supplemental devices can include hook and rod arrangements, screw arrangements and a number of other devices which include straps, wires, and bands, all of which are used to immobilize one portion of the spine relative to another. All of these devices generally require extensive surgical procedures in addition to the extensive procedure surrounding the primary fusion implant.
[0006] It would be advantageous if the device and procedure for supplemental spine fixation were as simple and easy to perform as possible, and were designed to leave intact as much bone, ligament, and other tissue which comprise and surround the spine, as possible.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to providing a supplemental spine fixation device and method for alleviating discomfort associated with the spine and as an adjunct, if desired, to a primary spine fusion technique.
[0008] The present invention provides for a method and apparatus for assisting in the fusing together of vertebral bodies of the spine. One of the features and purposes of the invention is to immobilize the vertebral bodies while spine fusion is accomplished. Fusion can require upwards of six months for bone cells from the upper and lower vertebral bodies to grow towards each other, generally through a primary fusion device.
[0009] In order to assist in the fusing process, the supplemental spinal fixation device and method of the invention immobilizes the vertebral bodies by immobilizing the respective spinous processes extending therefrom. The present device and method of the invention is minimally invasive such that it does not add to the trauma of the primary fusion procedure, especially if the fusion procedure is from a posterior approach. With an anterior fusion approach, additional posterior incisions are required. However, these are minimal when compared to other devices and methods.
[0010] It is also to be understood that the apparatus and method of the present invention can be used without spinal fusion in order to immobilize the spinous processes.
[0011] Accordingly, an object of the present invention is to increase the rigidity and stability with respect to the adjacent spinous process and vertebral bodies in order to promote inter-body fusion between the vertebral bodies. A further object is to provide for such rigidity and stability without interbody fusion. For example the embodiment of the present invention can be used with an inventive spinous process distraction mechanism.
[0012] It is yet a further object of the present invention to provide for an implant and method which does not require modification of the bone, ligaments, or adjoining tissues. In other words, it is an object of the present invention to provide for an implant and method which does not require that the bone be reshaped, notched, or in anyway modified. It is also an object that there is as little modification as possible to soft tissue and ligaments surrounding the bone.
[0013] It is a further object of the present invention to provide for an implant and method which can be inserted from one side of adjacent spinous processes in order to immobilize the spinous processes and resultingly immobilize the adjacent vertebral bodies. By addressing the spinous processes from one side, the objects and advantages of a minimally invasive procedure with reduced trauma, can be accomplished.
[0014] It is yet a further object of the present invention to provide for a device which has securing and/or hook elements which can easily and conveniently be secured about the spinous processes, which hook devices are preferably designed in order to accommodate the shape of the spinous processes and preferably swivel or pivot in order to accommodate the position and shape of one spinous processes relative to another.
[0015] It is yet another object of the present of the invention to provide for a device which has several degrees of freedom in order to allow a portion of the device to be positioned between spinous processes in order to distract part the spinous processes and other portions of the device to engage the spinous processes in order to rigidly immobilize the spinous processes. These degrees of freedom allow the device to conform to the bones, ligaments, and tissues of each individual patient. Thus, the present device allows for adjustments along two and three axis in order to successfully immobilize spinous processes.
[0016] It is yet another object of the invention to provide a device and method for securing together adjacent spinous processes which device is rigid and can keep the spinous processes aligned.
[0017] Other aspects, objects and advantages of the invention are evident from the specification, the claims and the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of an embodiment of the present invention;
[0019] [0019]FIG. 2 is a perspective view of an embodiment of the present invention of FIG. 1 illustrating the mobility of the connection rods;
[0020] [0020]FIG. 3 is a front view of an embodiment of the present invention of FIG. 1;
[0021] [0021]FIG. 4 is a front view of an embodiment of the present invention of FIG. 1 illustrating that the engagement members can individually rotate;
[0022] [0022]FIG. 5 is a perspective view of yet another embodiment of the present invention illustrating two spacers;
[0023] [0023]FIG. 6 is a perspective view of an embodiment of the spacer of the invention of FIG. 1;
[0024] [0024]FIG. 7 is a perspective view of an embodiment of the rotatable engagement elements of the invention of FIG. 1;
[0025] [0025]FIG. 8 is a perspective view of an embodiment of the present invention, illustrating the fastening bolts in an alternative arrangement and FIG. 8 a is a side view showing a portion of this alternative embodiment;
[0026] [0026]FIGS. 9 a and 9 b; FIG. 9 a is a front view of an embodiment of the clamp of the present invention; FIG. 9 b is a cross-sectional view of the clamp in FIG. 9 a through line A-A; and
[0027] [0027]FIGS. 10 a and 10 b; FIG. 10 a is a top view of an embodiment of the connection rod of the present invention; FIG. 10 b is a partial cross-sectional view of the connection rod in FIG. 9 a through line A-A.
[0028] [0028]FIG. 11 depicts the embodiment of the invention of FIG. 1 implanted between adjacent spinous processes.
[0029] [0029]FIG. 12 depicts an alternative embodiment of the present invention used with an inventive spinous processes distractor.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring to FIGS. 1 - 4 , the implant device 100 has a spacer 102 , a first rotatable engagement element or hook 104 , a second rotatable engagement element or hook 106 , a first connection rod 108 , a second connection rod 114 , and clamps 110 . By way of example only, these elements may be manufactured from stainless steel, titanium or any other biologically acceptable material.
[0031] The spacer 102 in FIG. 1 is substantially cylindrical in shape with an elliptical cross-section and a small diameter and a large diameter. The small diameter provides the height or distance between spinous processes. The small diameter of the spacer 102 is, by way of example only, 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm. Additionally, the spacer 102 may consist of other shapes in cross-section such as, but not limited to, egg-shaped, oval or circular. In a preferred embodiment until locked in place by bolt 103 , the spacer 102 can rotate so that it may accommodate the shape of the spinous process it contacts.
[0032] The spacer 102 also has a tapered front end, lead-in guide, or tissue expander 112 , a stem 113 and a threaded section 115 (See FIG. 6). As previously mentioned, the spacer 102 is placed between adjacent spinous process. Thus, the spacer 102 must be urged through the interspinous ligament. A physician will make an initial opening in the interspinous ligament to prepare the area for the spacer 102 . The tapered front end 112 minimizes the size of the initial opening a physician must make in the interspinous ligament. The tapered front end 112 can fit into the small initial opening and then distract the interspinous ligament to a height substantially equal to the small diameter of the spacer 102 as the spacer 102 is completely urged through the interspinous ligament. Thus, the tapered front end 112 minimizes trauma to the ligament tissue which promotes a faster recovery.
[0033] The spacer 102 is attached with the first connection rod 108 and the second connection rod 114 by the bolt 103 . Until tightened, the bolt 103 allows the first and second connection rods 108 , 114 to rotate relative to the spacer (see FIG. 2). This allows the hooks 104 , 106 to engage a spinous process that are at different angles and distances relative to the spacer 102 .
[0034] The first and second hook 104 , 106 (FIG. 1) have an engagement element 116 , a tapered front end 118 and a stem 117 with a movement limiter 119 (FIG. 7). The tapered front end 118 is adapted for urging between adjacent spinous processes. Similar to the spacer 102 , the front end 118 includes a tip or pyramid. This tip or pyramid allows a physician to make a minimal initial opening in the interspinous ligament where the hook 104 , 106 will be inserted. The front end 118 is urged into the initial opening and will distract the opening as the hook 104 , 106 engages the spinous process. By creating a small initial opening, the tapered front end 118 allows the first and second hook 104 , 106 to be inserted between adjacent spinous processes while minimizing the damage to the interspinous ligament tissue.
[0035] Preferably, the engagement element 116 is U-shaped. One of ordinary skill in the art will appreciate that the engagement element 116 may comprise other shapes such as, but not limited to, rectangular and triangular. The engagement element 116 is intended to be positioned substantially around the spinous process (FIG. 11) such that the engagement element 116 will restrain the spinous processes from movement caused by bending forward. The shape of the first and second hook 104 , 106 are such that the spinous processes do not need to be altered or cut away in any manner in order to accommodate the present invention. This is an improvement over the prior art because many prior devices require altering the spinous processes, such as cutting notches or grooves in the spinous processes. Further, the implant device 100 requires little if any altering to the ligaments and soft tissues surrounding the spinous processes. Generally, at most, ligaments would be pierced and/or urged apart. Altering the spinous processes in any manner can weaken the structure and can lead to complications in the future.
[0036] The first and second connection rod 108 , 114 have a first end 128 and a second end 132 . The first end 128 has a bore 130 extending through (See FIGS. 10 a and 10 b ). The spacer 102 is connected to both the first and second connection rods 108 , 114 . To attach the spacer 102 with the first and second connection rod 108 , 114 , the stem 113 (see FIG. 6) of the spacer 102 is inserted through the bore 130 of each connection rod 108 , 114 . The spacer 102 is then secured to the first and second connection rod 108 , 114 by engaging the bolt 103 with the threaded portion 115 of the stem 113 . With the bolt 103 fastened to the stem 115 , the first and second connection rod 108 , 114 can pivot about the longitudinal axis of the spacer 102 . The spacer 102 can also rotate as indicated above. Fully tightening bolt 103 fixes the position of the spacer 102 and the connection rods 108 , 114 .
[0037] The first hook 104 is also connected with the second end 132 of the first connection rod 108 . The hook 104 is secured to the connection rod 108 by clamp 110 . As illustrated in FIGS. 9 a and 9 b, the clamp 110 includes clamping elements 109 and 111 , each of which has a channel 140 and a bore 142 extending through. The bore 142 has a limiting cavity 143 . The diameter of the two channels 140 is substantially similar to the diameter of the first connection rod 108 . The diameter of the bore 142 is substantially similar to the diameter of the stem 117 of the first hook 104 .
[0038] The clamp 110 is slidably attached with the first connection rod 108 . The stem 117 of the first hook 104 is inserted through the bore 142 . By inserting the stem 117 through the bore 142 , the limiter 119 fits within the limiting cavity 143 . The limiter 119 prevents the hook 104 from rotating completely around. The second end 132 of the first connection rod 108 is placed through the channel 140 . Without tightening the bolt 144 to the threaded portion 121 of the stem 117 , the clamp 110 can be moved to any position along the first connection rod 108 . Similarly, the clamp 110 can be rotated about the longitudinal axis of the connection rod 108 to any angle relative to the first connection rod 108 . Additionally, the first hook 104 can be rotated about the longitudinal axis of its stem 117 , until the limiter 119 contacts either edge of the limiting cavity 143 . It is to be understood that in another embodiment with the limiter 119 removed, the hook 109 , 106 can rotate completely around until locked in position by bolt 144 .
[0039] To secure both the clamp 110 to the connection rod 108 and the hook 104 to the clamp 110 , the bolt 144 engages the threadable portion 121 of the stem 117 . By tightening the bolt 144 the diameter of the channel 140 decreases causing and the clamp 110 to tighten around the connection rod 108 . The second hook 106 is attached with the second connection rod 114 in a similar fashion.
[0040] Preferably, the hooks 104 , 106 can be positioned at any angle and location along the connection rods 108 , 114 . Preferably, the first and second hooks 104 , 106 have three degrees of freedom. The separation between the spacer 102 and the hooks 104 , 106 likely differs as the distance between each is dictated by the placement of the initial opening and the location of the spinous processes. Therefore, the hooks 104 , 106 will likely be positioned at different locations along the connection rods 108 , 114 and at different angles relative to the spacer 102 when the spacer is urged between spinous processes and with each hook 104 , 106 engage the spinous processes.
[0041] The embodiments described so far are intended to rigidly fix two spinous processes relative to one another. However, more than two vertebrae can be fused together. As illustrated by FIG. 5, the implant device 100 may contain two spacers 102 . With the exception of an additional spacer 102 and a third connection rod 99 which has a bore 130 at each end, the elements of this embodiment are substantially the same as the embodiments in FIGS. 1 - 4 . This embodiment also functions similar to the embodiment previously described above. The additional spacer 102 is connected to connecting rods 99 and 114 . One of the bores 130 of the connecting rod 99 is aligned with the bore 130 of the connecting rod 114 . The stem 113 of the second spacer 102 allows the bolt 98 to encircle the threaded portion 115 . Tightening the bolt 98 will fasten the second spacer 102 to both the connecting rods 109 , 114 . Even though the remaining portion of this specification describes the present invention with only one spacer 102 , the description also applies to the embodiment with multiple spacers 102 .
[0042] The device 100 is designed to be implanted via a minimally invasive procedure. In a preferred method, the patient is placed in a lateral decubitus position with maximum flection of the lumbar spine. The patient can be on his or her side to insure proper orientation of the implant device 100 . The implant device 100 will be preferably inserted between the spinous processes from the bottom or right side of the spinous processes to the top or left side of the spinous processes. This method permits easy visualization of the implant device 100 assembly.
[0043] Once an incision has been made and the implant area is accessible, the physician will first urge the first hook 104 between spinous processes to engage the spinous process. The physician can adjust the position of the first hook 104 so that the engagement element 116 is properly secures around the spinous process. The physician can then urge the second hook 106 between adjacent spinous processes at the same time as, or after, the first hook 104 is inserted. Similarly, the second hook 106 can be positioned so that the engagement element 116 engages the spinous process, which spinous process would be below the spacer 102 . The physician can then urge the spacer 102 between adjacent spinous processes. At this point, preferably the connecting rods 108 , 114 are connected to the spacer 102 . The physician can attach both hooks 104 , 106 to the connection rods 108 , 114 . This is the preferred method as the hooks should be more easily insertable about the two adjacent spinous processes prior to the spacer being inserted. This is because as the spacer is inserted between the two adjacent spinous processes, and thus generally distracts the adjacent spinous processes, the two adjacent spinous processes move closer to their respective adjacent spinous process, reducing the space where the hooks would be inserted. It is to be understood, however, that any combination of method steps of inserting and connecting together the spacer 102 and the hooks 104 , 106 and the connecting rods 108 , 114 fit within the spirit and scope of the invention. Thus, the hooks 104 , 106 and the spacer 102 can be inserted prior to being attached to the connecting rods 108 , 114 . Alternatively, the connecting rods 108 , 114 can be attached to the hooks 104 , 106 before the hooks 104 , 106 are inserted and thereafter attached to the spacer 102 after the spacer 102 is inserted.
[0044] As previously mentioned, the spacer 102 and first and second hooks 104 , 106 are inserted between adjacent spinous processes from only one side. Further, securing the spinous processes by first and second hooks 104 , 106 with the engagement element 116 does not require altering the spinous process. Thus, this method minimizes the damage to surrounding body tissue and promotes a faster recovery than the typical method.
[0045] The above methods use a small incision through which the pieces of the invention are inserted. However, yet another alternative method would be for the implant device 100 to be inserted through a larger incision, with the entire implant device 100 fully assembled. Prior to insertion, the bolts 103 , 144 could be loosened so that the engagement portion 116 can be positioned around the spinous processes at about the same time that the spacer 102 is inserted between the spinous processes. Once this is accomplished, the spinous processes could be drawn down tightly around spacer 102 , with the engagement portion 116 finally positioned around the spinous processes. All the bolts would then be tightened.
[0046] As indicated above, the implant device 100 can be implanted using a number of methods, preferably, once a primary spine fixation device is implanted between the vertebral bodies. It is to be understood, however, that this supplemented spine fixation device 100 of the invention can also be used by itself if it is desired to immobilize spinous processes relative to each other. Still alternatively as described below, another embodiment can be used with an independent spacer.
[0047] As a further embodiment of the invention, the device of FIG. 1 can eliminate the body of the spacer 102 (FIG. 12) with the connecting rods 108 , 114 still secured together with bolt 103 and a stem 115 with a threaded section connected to a small stop 121 , that is bigger than the bore 130 in the rods. This arrangement would keep the connecting rods 108 , 114 together and allow them to rotate relative to each other until the bolt 103 is tightened. This device is used to limit the spreading apart of the spinous processes during flexion or forward bending. As can be seen in FIG. 12, this embodiment of the invention can be used, if desired with an inventive interspinous process distraction system 200 such as any of the variety of systems presented by the present assignee. These systems 200 are more fully described in the patents and patent applications referenced and incorporated herein under the cross-reference section.
[0048] [0048]FIGS. 8 and 8 a depict an alternative embodiment of the invention wherein the fastening and tightening bolts 103 and 144 are supplemented with alternative bolts such as bolt 182 in FIG. 8 a. These bolts are mounted at approximate 90 degrees to the other bolts 103 , 144 in order to allow the surgeon to tightened these bolts while looking at them head on, as opposed to looking at them from the side as would be the case with bolts 103 , 144 . This is thus more convenient for the physician to assemble and tightened. As shown in FIG. 8 a, for this arrangement, the clamp 110 includes an additional clamp element 180 . In this additional clamp element 180 another bolt as indicated above, bolt 182 is mounted. This bolt is essentially either a quarter or half turn bolt such that when the bolt is turned either a quarter or a half turn, a caming member 184 extends from the clamp member 180 in order to be urged against the adjacent clamp member, tightening that clamp member against the connecting rod 114 . In operation, the hook 106 and clamp 110 would be preassembled and then at the surgical site slid over the connecting rod 114 . After the hook 106 is positioned between spinous processes, the nut 182 can be turned in order to extend the caming member 184 from the clamp element 180 against the remainder of the clamp 110 in order to lock the hook 106 in place on the connecting rod 114 . It is to be understood that a similar arrangement can be accomplished with respect to the clamp mechanism which holds the spacer 102 to the connecting rods 108 , 114 .
[0049] As yet a further embodiment of the invention, the device of FIG. 1 can be modified to eliminate the second connecting rod 114 and the second hook 106 with the engagement element 116 . In this embodiment, the engagement portion 116 of the first hook 104 serves to keep the spacer 102 in place between adjacent spinous processes. So configured, the inventive device 100 aids to limit extension without inhibiting flexion or focused bending.
[0050] The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence.
|
The implant device is a minimally invasive device for assisting in the fusing together of vertebral bodies of the spine. The implant device immobilizes the vertebral bodies by immobilizing the respective spinous process extending from the vertebral body. The implant device has at least one spacer and hook to immobilize adjacent spinous processes. The spacer and hook are fastened to connection rods. Each connection rod can individually traverse through a range of motion, allowing each hook to engage the respective spinous process.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of copending application Ser. No. 551,372, filed Nov. 10, 1983.
BACKGROUND OF THE INVENTION
This invention relates to novel atrial peptides having useful natriuretic activity.
It is known that the cells of the atrial myocardium in mammals contain numerous membrane-bound storage granules. These characteristic secretory granules, which have been observed in the rat, dog, cat and human atria, resemble those which are in peptide-hormonal producing cells. See DeBold et al., J. Histochem. Cytochem. 26, 1094-1102 (1978). It has been reported that crude tissue extracts of atrial myocardium when injected intravenously into non-diuretic rats produced a rapid and potent natriuretic response. See DeBold et al., Life Sciences 28, 89-94 (1981). Partial purification of rat atrial homogenates with a brief boiling step and fractionation on Sephadex® was achieved by Trippodo et al., Proc. Soc. Exp. Biol. Med. 170, 502-508 (1982). Natriuretic activity was found by these investigators in the overall molecular weight range of 3600 to 44,000 daltons and in peptide fractions of both the higher molecular weight range of 36,000-44,000 daltons and a lower molecular weight range of 3600-5500 daltons.
In a more recent publication, DeBold et al., Fed. Proc. 42(3), Abstract 1870, page 611 (1983), report the purification of an atrial natriuretic peptide having a molecular weight of 5150 daltons and a sequence of 47 amino acids which the investigators designated "Cardionatrin I". Three additional peaks with natriuretic activity were obtained by high performance liquid chromatography (HPLC) procedures.
In a still later publication, Grammer et al., Biochem. Biophys Res. Commun. 116(2), 696-703, Oct. 31, 1983, disclose the partial purification of a rat atrial natriuretic factor having a molecular weight of approximately 3800 and containing 36 amino acid residues.
Rat atrial extracts also have been fractionated into low molecular weight fractions (<10,000 daltons) and high molecular weight fractions (20,000-30,000 daltons) both of which in vitro relaxed smooth muscle and were potent natriuretic agents when administered intravenously to rats. See Currie et al., Science 221, 71-73 (1983).
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, novel peptides are provided which exhibit useful natriuretic activity. These biologically active peptides have the following amino acid sequence:
R.sub.1 -cys-phe-gly-gly-arg-ile-asp-arg-ile-gly-ala-gln-ser-gly-leu-gly-cys-asn-R.sub.2
wherein
R 1 =H, ser, ser-ser, and
R 2 =OH, ser, ser-phe-arg, ser-phe-arg-tyr,
or the physiologically acceptable salts, esters or amides thereof.
In the peptide structure, the amino acid components are designated by conventional abbreviations as follows:
______________________________________Amino Acid Abbreviated Designation______________________________________L-Alanine alaL-Arginine argL-Asparagine asnL-Aspartic Acid aspL-Cysteine cysL-Glutamine glnGlycine glyL-Isoleucine ileL-Leucine leuL-Methionine metL-Phenylalanine pheL-Proline proL-Serine serL-Tyrosine tyr______________________________________
The peptide materials of this invention have been isolated in a highly purified form which did not exist in the rat myocardium from which they were initially obtained. That is, they have been prepared in a form which is essentially free of other peptides, and free from other cellular components and tissue matter. These new atrial peptides exhibit physiological characteristics which suggest that they are important to medical science in the study of the endocrine system of the cardiac atria with respect to humoral agents for modulation of extracellular volume, sodium and vascular resistance.
In particular, the novel peptides of this invention have indicated therapeutic use as a diuretic, natriuretic, renal vasodilator and smooth muscle relaxant. That is, they exert profound effects on sodium, urine volume, renal vasodilation and smooth muscle tone.
In brief, these novel peptides have been obtained by fractionation of rat atrial extracts by gel filtration chromatography to provide a high and a low molecular weight fraction, both of which had useful natriuretic activity. The lower molecular weight peak was resolved by ion-exchange chromatography into two peaks which possessed natriuretic activity and which either preferentially relaxed only the intestinal (chick rectum) muscle strips or which relaxed both vascular (rabbit aorta) and intestinal smooth muscle preparations. The intestinal smooth muscle relaxant was separated into 4 peaks and purified to homogenity by reversed phase high performance liquid chromatography (HPLC). Sequence analysis established the structure of this serine-, glycine-rich peptide and demonstrated that the four biologically active peptides differed from each other by the lack of the first and the second amino terminal serine residues or of the C-terminal serine residue, respectively. The 21 amino acid peptide was designated atriopeptin I, and the other three peaks which relaxed intestinal strips and were natriuretic and diuretic, but which were ineffective on blood vessel strips, were designated des-ser 1 -atriopeptin I, des-ser 1 , ser 2 -atriopeptin I and des-ser 21 -atriopeptin I, respectively.
Similarly, the vascular smooth muscle relaxant which was the more potent natriuretic-diuretic compound was resolved into two major peaks on HPLC. Surprisingly, the amino terminal 21 amino acids of both rabbit aorta relaxants was homogeneous with that of the intestinal relaxant but the 23 amino acid peptide (designated atriopeptin II) possessed a phe-arg, and the 24 amino acid peptide (designated atriopeptin III) was extended by a phe-arg-tyr at the carboxy terminus. This family of closely related peptides is believed to be derived from a similar high molecular weight precursor and the biological selectivity and potency of the smaller peptides may be determined by the action of a limited sequential proteolytic cleavage.
The shorter 21 amino acid peptide (designated atriopeptin I) relaxes intestinal but not vascular smooth muscle and is natriuretic and diuretic in vivo. The second peptide (atriopeptin II) contained 23 amino acids, i.e. the same 21 amino acids with a C-terminal phe-arg extension which results in an agent that relaxes both vascular and intestinal smooth muscle as well as being a potent natriuretic-diuretic in vivo.
DETAILED DESCRIPTION OF THE INVENTION
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the present invention, it is believed that the invention will be better understood from the following detailed description of preferred embodiments of the invention taken in connection with the accompanying drawings in which:
FIG. 1 is a graphical representation which shows the comparative intestinal smooth muscle relaxant activity (chick rectum relaxation in mm) of the novel atrial pepetides in one embodiment of the invention.
FIG. 2 is a graphical representation which shows the comparative vascular smooth muscle relaxant activity (rabbit aorta relaxation in mm) of the novel atrial peptides in another embodiment of the invention.
The initial source material for isolating the peptides of this invention was the frozen rat heart. Over 2500 such rat hearts were subjected to a sequence of steps for the isolation of the desired peptides. The steps for isolation can be briefly described as:
(a) Preparing a crude homogenate of mammalian atrial tissue and centrifuging;
(b) Boiling the supernatant and centrifuging;
(c) Desalting the supernatant by gel filtration chromatography on Sephadex® G-15 resin;
(d) Gel filtration chromatography of the protein fraction on Sephadex® G-75 resin;
(e) Ion exchange chromatography of the low molecular weight protein fraction on SP-Sephadex® C-25 resin;
(f) High performance liquid chromatography (HPLC) of the two main protein fractions; and;
(g) Recovering the separated atrial peptide fractions.
The aforesaid Sephadex chromatography resins are well-known materials available from Pharmacia Fine Chemicals, Piscataway, NJ.
Bioassays of the isolated peptides were made on rabbit aorta strips and on segments of chick rectum under physiologically acceptable conditions. Rabbit aorta strips maintained in tone by a continuous infusion of norepinephrine constituted a reliable and sensitive assay tissue. Use of an isolated carbachol-(a muscarinic agent) contracted chick rectum preparation, however, provided a more rapid and simpler assay that facilitated the testing of a larger number of samples.
Natriuretic activity of the isolated peptides was determined by injecting intravenously in rats and determining the effect on fractional sodium excretion in the urine.
These methods of determining biological activity (smooth muscle relaxant and natriuresis) as developed by a research group led by the inventor are further described by Currie et al., Science 221, 71-73 (1983).
The following detailed Examples will further illustrate the invention although it will be understood that the invention is not limited to these specific Examples. In the Examples, CRF means chick rectum factor while RAF means rabbit aorta factor.
EXAMPLE 1
Methods
Relaxation of smooth muscle in vitro
Bioassay. Spiral strips of rabbit thoracic aorta and segments of chick rectum under 1 gm tension were continuously perfused at 10 ml/min with oxygenated Krebs-Henseleit solution (37°). Resting tone was induced by either 2×10 -8 M norepinephrine (aorta) or 2×10 -8 M carbachol (rectum). The effects of test substances then were determined by application with micropipets to the stream of medium flowing over the tissues, using as standards nitroglycerin (aorta) and isoproterenol (rectum). Column fractions were freeze dried and residues dissolved in phosphate buffered saline for bioassay.
Natriuresis. The natriuretic activity of extracts was determined in 250-300 gm male Sprague-Dawley rats under dial-urethane anesthesia. A suprapubic silastic bladder catheter was placed for urine collection and a tail vein catheter was used for infusion of 0.225% NaCl in 5% dextrose solution at 38 μl/min. After an equilibration period of one hour, two 10 minute (min) baseline urine collections were followed by rapid intravenous injection of the test substance and 3 more ten min urine collections completed. Following a one hour re-equilibration period, a second set of collections with a second injection of the test substances was completed. Urine volume was determined by weighing in tared containers. Sodium concentration was measured by flame photometry.
Preparation and purification of chick rectum factor (CRF) and rabbit aorta factor (RAF)
Homogenates were prepared from frozen atrial tissue in ˜30 g lots derived from 200 rats by dispersion in 10 vol/wt tissue of phosphate buffered saline in a 1 quart Waring blender (1 min) followed by Polytron PT20ST (20 seconds) at maximum speed. Suspensions were centrifuged 10 min at 200×g. After heat treatment (10 ml aliquots in 18×150 mm test tubes immersed 10 min in a boiling water bath) this supernatant was centrifuged again at 12000×g for 10 min. Acetic acid (glacial) then was added to the supernatant fluid to 0.5M, and the resultant suspension clarified by a final centrifugation (27000×g for 15 min). The supernatant was chromatographed on a G-15 Sephadex column (8×36 cm) in 0.5M acetic acid at 600 ml/hr and the protein fraction was concentrated by freeze drying. The combined material derived from 600 rats then was dissolved in 0.5M acetic acid and supplied to a 5×90 cm G-75 Sephadex column, eluting with 0.5M acetic acid at 96 ml/hr. Biological activity (smooth muscle relaxant and natriuresis) was found by assay methodology previously described by Currie et al., Science 221, 71-73 (1983) in two peaks: a high (20,000 to 30,000) and a low (less than 10,000) molecular weight fraction.
Further purification of the low molecular weight fraction was achieved by ion exchange chromatography. The combined material from 1200 rats was applied to a column of SP-Sephadex C-25 (20 gm, dry weight, forming a 5×7 cm column) in a 25 mM ammonium acetate/500 mM acetic acid. The chromatogram was developed by application of a linear gradient of ammonium acetate increasing at 23.4 mM/hr at a flow rate of 96 ml/hr, with the acetic acid held at 500 mM. Biological activity was found only in two main fractions: one, designated peak CRF (eluted at 150 mM ammonium acetate), which contained chick rectum relaxant factor (CRF), and the second, designated peak RAF (at 270 mM ammonium acetate), which contained rabbit aorta relaxant factor (RAF). Both fractions were enriched in natriuretic activity as well.
The final stage of purification was accomplished by HPLC with UV monitoring at 215 nm. The CRF and RAF fractions from the SP-Sephadex column were lyophilized repeatedly to remove volatile materials, redissolved in 0.1% trifluoroacetic acid, and then HPLC was run on a Brownlee RP-300 Aquopore Column (4.6 mm×25 cm) using the following gradients at 1.0 ml/min. CRF: 0→10%A over 3.8 min then 10%A→14.8%A over 60 min then 14.8%A→16.4%A over 100 minutes. Three peaks of CRF activity eluted at 113.8 min. RAF: 0→16%A over 3.6 min then 16%A→22.4%A over 80 minutes. A band of RAF activity eluted at 48.8 min. In all cases solvent A=0.1% trifluoracetic acid/acetonitrile, B=0.1%, trifluoroacetic acid/H 2 O. The bioactive fractions were reinjected on a Vydac column (C 18 , 300 Å pore size, 4.6 mm×25 cm) acid eluted at 1.0 ml/min using a gradient of 0→50%C over 50 min. The CRF sample resolved into one major peak (CRF I, 29.3 min) and two minor peaks (CRF-II and -III, 29.5, 29.7 min). The RAF sample provided a major peak (RAF-I, 31.0 min) and a minor peak RAF-II, 31.5 min). Products were lyophilized and when stored at -20°, exhibited good stability.
Edman degradation. The above-isolated polypeptides were sequentially degraded utilizing an Applied Biosystems Model 470A gas phase sequencer as described by Hunkapiller et al., Methods in Enzymol. 91 (1), Chapter 36, Academic Press, N.Y., 1983. Several modifications included the omission of benzene as one of the solvents employed, and the replacement of methanol with acetonitrile as solvent 4 in the system. In addition, the conversion reagent utilized (reagent 4) was 25% trifluoracetic acid (in H 2 O v/v). Coupling times were reduced to about 600 sec total, while cleavage times remained at 850 sec. Thirty or more cycles were completed in each run with one degradation each for CRF (665 pmoles output yield), reduced/alkylated CRF (600 pmoles), and RAF (1178 pmoles). Phenylthiohydantoin amino acids were identified using high performance liquid chromatography as adapted from Hunkapiler and Hood, Methods in Enzymol. 91 (1), Chapter 43, Academic Press, N.Y., 1983. Average repetitive yield values of 91% were determined for those amino acid derivatives deemed worthy of accurate quantitation.
The method described, above, provides the sequence of steps followed in the purification of 1,200 rat hearts. In order to assign a relative biological activity, the relaxant activity of the atrial extracts was compared to a nitroglycerin standard curve on the blood vessel (rabbit aorta) strips and to isoproterenol on the intestinal (chick rectum) strips. The initial crude homogenate of rat atria was too contaminated to determine total activity. The 10 min. boiling step facilitated the purification by eliminating a great deal of protein prior to desalting on the Sephadex G-15 column. The low molecular weight fraction obtained from the gel filtration column was further separated on the ion exchange column based on differences in the preferential spasmolytic activity of the various fractions. Thus, testing a 10 μl aliquot of each fraction demonstrated the presence of two peptides, one of which preferentially relaxed the intestinal smooth muscle and one which at low dose preferentially relaxed the blood vessel strip. However, a complete dose-response analysis of both peaks indicated that chick rectum relaxant exhibited a pronounced selectivity such that even high dose of this peptide was impotent as a blood vessel relaxant. On the other hand, the second peak produced concentration dependent relaxation of both the intestinal and vascular strips. The peak with the preferential selectivity, i.e. the chick rectum relaxant, which also possessed the natriuretic-diuretic activity in vivo, was further investigated as described herein.
The lyophilized chick rectum active factor (CRF) obtained from the SP Sephadex column was fractionated by reversed phase (Brownlee C 18 ) HPLC. The CRF was separated into three major fractions (I-III). Each fraction was lyophilized and rechromatographed by HPLC on a VYDAC column (C 18 , 300 Å pore size). There was thus obtained 60 μg protein of CRF-I, 25 μg of CRF-II, and 25 μg of CRF-III. CRF-I was quantitated as a smooth muscle relaxant and produced a concentration dependent relaxation but did not relax the precontracted aorta strips. Intravenous administration of CRF-1 protein produces an increase in urinary sodium concentration.
The purified CRF-I sample was analyzed by gas phase sequencing. The sequences of the closely related low molecular weight spasmolytic/natriuretic peptides as determined in this Example 1 are shown in Table 1, below. The peptides exhibit a large number of serine and glycine residues. The CRF-II and CRF-III merely lack the amino terminal one or two serines present in CRF-I, thereby suggesting that they are amino peptidase cleavage products. The intestinal receptor recognition appears to be tolerant of losses on the amino termius since CRF-II and III are fully biologically active.
The purified low molecular weight peptide designated RAF-1 which exhibited a preferential relaxation of vascular smooth muscle was further analyzed with the gas phase sequentator. Surprisingly, the sequence of the initial 21 amino acids of RAF-I are exactly the same as those observed for CRF-1. The major difference in the peptides resides in the carboxyl terminus. RAF-I is a potent vascular smooth muscle relaxant in vitro and a selective renal vasodilator in vivo. RAF-I also appears to be considerably more potent as a natriuretic substance than CRF-I. The latter peptide requires large doses and produces a variable in vivo response.
TABLE 1______________________________________Amino Acid Sequences______________________________________CRF-I:Ser--ser--cys--phe--gly--gly--arg--ile--asp--arg--ile--gly--ala--gln--ser--gly--leu--gly--cys--asn--serCRF-II: des--ser.sup.1 - CRF-ICRF-III: des--ser.sup.1, ser.sup.2 - CRF-IRAF-I:Ser--ser--cys--phe--gly--gly--arg--ile--asp--arg--ile--gly--ala--gln--ser--gly--leu--gly--cys--asn--ser.sup.21 --phe--arg.sup.23______________________________________
RAF-I and CRF-I can readily be differentiated by charge (on ion exchange chromatography) and mobility on reversed phase HPLC. The carboxy-terminal sequence of the peptides dictates their biological specificity. The shortened carboxy terminus on CRF-I restricts its biological activity to relaxation of the intestinal smooth muscle and weak natriuretic activity. This peptide does not relax isolated blood vessel strips nor does it reduce renal resistance in vivo. On the other hand, the extended carboxy terminal in RAF-I includes the structural features required for vascular receptor recognition and for the initiation of natriuresis and diuresis. The homogeneous nature of amino terminal 21 amino acids in CRF and RAF strongly indicate that they may be derived from the same precursor peptide. Aminopeptidase cleavage of at least the initial two serine residues does not radically compromise biological activity. However, the site of attack on the carboxy portion of the atrial peptide appears to dictate the ultimate biological response. The proteolytic enzyme provides an ideal site for the regulation of the physiological actions of these spasmolytic (natriuretic) peptides.
EXAMPLE 2
Materials and Methods
Purification Scheme
Fourteen hundred frozen rat atria (Biotrol, Indianapolis, IN) were trimmed of extraneous tissue (153 gm wet wt), homogenized in 10 volumes of phosphate buffered saline in the presence of phenylmethylsulfonyl fluoride (1 μ/ml, Sigma Chemical Company, St. Louis, MO) and centrifuged at 2500×g for 10 min. The supernatant was divided into 10 ml aliquots and immersed in a 100° bath for 10 min and centrifuged at 10,000×g for 10 min at 4°. The supernatant was adjusted to 0.5M acetic acid and applied to a Sephadex G-15 column (8×36 cm) and eluted with 0.5M acetic acid (600 ml/hr). The column effluent was lyophilized and reconstituted in 0.5M acetic acid, applied to a Sephadex G-75 column (5×90 cm) and eluted with 0.5M acetic acid at 96 ml/hr. The lyophilized low molecular weight fraction from the G-75 column was applied to SP-Sephadex C-25 (20 g gel, 5×7 cm column) in 25 mM ammonium acetate/0.5M acetic acid and eluted with a linear gradient of ammonium acetate (23.4 mM/hr at 96 ml/hr) in 0.5M acetic acid. Two biologically active fractions eluted at 160 mM which relaxed intestinal but not vascular smooth muscle strips and the other at 270 mM relaxed both vascular and intestinal assay strips. Following lyophilization the low molecular weight peaks were individually purified by reversed phase high pressure liquid chromatography on a Brownlee RP-300 aquapore column (4.6 mm×25 cm) using a mixture of solvent A (0.1% trifluoracetic acid/acetonitrile) and B (0.1% trifluoracetic acid/water) at 1.0 ml/min.
The fraction that eluted from the SP-sephadex column at 160 mM ammonium acetate was run at 0 to 10% A over 3.8 min; then 10 to 14.8% A over 60 min; then 14.8 to 16.4% A over 100 minutes. Atriopeptin I eluted at 15.6% A, des-ser 1 -atriopeptin I eluted at 15.7% A, des-ser 1 , ser 2 -atriopeptin I eluted at 15.7% A, and des-ser 21 -atriopeptin I at 15.8% A. The SP-Sephadex fraction that eluted at 270 mM was separated on the same gradient on the HPLC with atriopeptin II being recovered from a gradient 0 to 16% A in 5.8 min and 16 to 22% in 80 min. at 19.6% A, and atriopeptin III at 21.1% A. The bioactive fractions were reapplied to a Vydac octadecasilyl column (300 Å pore size, 4.6 mm×25 cm) and eluted at 1.0 ml/min using a mixture of solvent A (0.05% trifluoroacetic acid in acetonitrile) and B (0.05% trifluoracetic acid in water) employing a gradient 0 to 30% over 30 min. Atriopeptin I appeared at 29.5% A; des-ser 1 -atriopeptin I at 29.7% A; des-ser 1 , ser 2 -atriopeptin I at 29.7% A; des-ser 21 -atriopeptin I at 29.9%A; atriopeptin II at 31.5% A; and atriopeptin III at 32% A from a gradient of 10 to 35% over 25 min. The polypeptides were sequentially degraded, utilizing an applied Biosystem Model 470 A gas phase sequencer as described in Example 1. Thirty or more cycles were completed in each run with one degradation each for: the reduced and alkylated atriopeptin I (600 pmoles output yield); des-ser 1 -atriopeptin I (660 pmoles); des-ser 21 -atriopeptin I (520 pmoles); des-ser 1 , ser 2 -atriopeptin I (650 pmoles); atriopeptin II (1200 pmoles), and atriopeptin III (850 pmoles). The atriopeptins were reduced and alkylated by dissolving the peptide (0.5-5 nmoles) in 90 μl of 2% SDS (sodium dodecylsulfate) in 0.4M Tris acetate (pH 9.0); 10 μl of 100 mM dithiothreitol was added, flushed with N 2 , capped and incubated at 37° for 60 min. Then 20 μl of a fresh solution of 120 mM iodoacetamide (which had been recrystallized 3×), flushed with N 2 , capped and incubated at room temp. for 10 min, then transferred to boiled dialysis tubing and dialyzed against 0.1% SDS for 2 hrs and redialyzed overnight followed by lyophilization. Phenylthiohydantoin amino acids were identified using high performance liquid chromatography as described in Example 1. Average repetitive cycle yields were greater than 90% for each cycle whose signal allowed accurate quantitation. The protein concentration of the purified peptides was determined by the method of Lowry et al., J. Biol. Chem. 193, 265-276 (1951). The smooth muscle bioassay technique was performed as described by Currie et al., Science 221, 71-73 (1983). Briefly, spiral strips of rabbit thoracic aorta and chick rectum were continuously superperfused at 10 ml/min with oxygenated Krebs-Henseleit medium (37°). In order to detect relaxant substances a resting tone was induced by infusing the vascular smooth muscle preparations with norepinephrine (2×10 -8 M.)
The natriuretic-diuretic assay (U Na V) percent of the baseline control was performed. The natriuretic-diuretic assay (U Na V-percent of baseline control) was performed in 250-300 gm Sprague-Dawley rats anesthetized with 0.4 ml dial-urethane. A suprapubic silastic catheter was placed in the bladder for urine collection and a tail vein catheter was used for infusion of 0.225% NaCl in 5% dextrose at 38 μl/min. After an equilibration period of one hour, two 10 min baseline urine collections were followed by rapid intravenous injection of the test substance and 3 more 10 min urine collections were completed. Urine volume was determined by weighing in tared containers. Sodium concentration was measured by flame photometery.
RESULTS
The purification protocol employed to produce peptides pure enough for sequence analysis is shown in Table 2, below. The initial crude homogenate of rat atria is too contaminated to determine total biological activity. The 10 min boiling step facilitated the purification by eliminating a great deal of protein prior to desalting on the Sephadex G-15 column. The low molecular weight fraction obtained from the gel filtration column was further separated on the ion exchange column based on differences in net charge and in the preferential spasmolytic activity of the various fractions. Thus, the testing of aliquots of each fraction demonstrated the presence of two major peptide fractions, one of which preferentially relaxed the intestinal smooth muscle and one which at low doses relaxed both the blood vessel and the intestinal strip. The lyophilized chick rectum active factor obtained from the SP-Sephadex column was fractionated by reversed phase (Brownlee C 18 ) HPLC into four fractions. Similarly, the peak that also possess the vascular relaxation activity was resolved into two main peaks (atriopeptin II and III). Each fraction was lyophilized and rechromatographed by HPLC on a VYDAC column and underwent sequence analysis. The sequences of the closely related low molecular weight spasmolytic/natriuretic peptides as determined in this Example 2 are shown in Table 3, below. The peptides exhibit a large number of serine and glycine residues and contain an internal disulfide ring. The four peptides that selectively act on intestinal but not vascular smooth muscle differ from each other because of the lack at the amino terminal of one or two serine residues, or lack of a C-terminal serine. The peptides that are potent vascular smooth muscle relaxants as well as intestinal spasmolytics contain a carboxyl terminal extension of phe-arg or a phe-arg-tyr in atriopeptin II and III, respectively.
A quantitative comparison of the biological activity of the various atrial peptides indicates that intestinal receptor recognition is tolerant of losses on the amino terminus since des-ser 1 -atriopeptin I and des-ser 1 , ser 2 -atriopeptin are active peptides. However, the lack of a phe-arg carboxy extension precludes vaso-relaxant activity and partially reduces in vivo natriuretic-diuretic activity. The in vitro and in vivo potency of atriopeptin II and III are comparable, suggesting that further extension of the C-terminus beyond arg may not further substantially alter activity. FIG. 1 and 2 illustrate this quantitative comparison of the biological activity of these atrial peptides by the assay methods utilizing the chick rectum and rabbit aorta, respectively, as described hereinbefore.
TABLE 2______________________________________ Specific Total (Re- Total Activity Activity covery Protein u/mg Units %)______________________________________Crude 5764 mg 7.7 44,000HomogenateBoiled Extract 728 154 (1X) 112,000 (100%)Sephadex G-15 262 265 (1.7X) 69,400 (62%)Sepahdex G-75 17.0 2,890 (18.8X) 49,100 (44%)SP-SephadexC-25:Intestinal 1.54 11,300 (73.4X) 17,400 (16%)RelaxantVascular 1.20 7,620 (49.5X) 9,140 (8%)RelaxantHPLC FractionsAP-I 0.114 37,600 (244X) 4,280 (3.8%)Mixture* 0.049 107,000 (695X) 5,220 (4.6%)des--ser.sup.21 -AP I 0.073 62,500 (406X) 4,550 (4.1%)AP-II 0.081 52,400 (340X) 4,260 (3.8%)AP-III 0.061 62,500 (406X) 3,810 (3.3%)______________________________________ Table 2. Purification of 153 g tissue (atria from 1400 rat hearts). The biological activity was compared on intestinal smooth muscle (chick rectum) strips. Quantitation achieved by performing dose response curves with each peptide in comparison to the response to a standard curve achieved with ispoproterenol (the intestinal relaxant). One unit of activity was set to be equivalent to 1 ng of isoproterenol. *Mixture of des--ser.sup.1 -AP I and des--ser.sup.1, ser.sup.2 -AP I. AP = Atriopeptin u = Units
TABLE 3__________________________________________________________________________ ##STR1## ##STR2## ##STR3## ##STR4## ##STR5## ##STR6##__________________________________________________________________________
The atrial peptides were tested in vivo in rats for natriuretic potency following intravenous injection of 2 μg of the six peptides. Atriopeptins II and III were equipotent and somewhat more active than atriopeptin I. Further shortening of the 21 amino acid length of the peptide by loss of serines at either the N- or C-terminus resulted in a reduction of the nutriuretic-diuretic potency. The results of this in vivo testing are set forth in Table 4, below.
TABLE 4______________________________________ ResiduePeptide No. n U.sub.Na V p Value______________________________________Atriopeptin (AP) I 1-21 7 1130 ± 38 <.05des--ser.sup.1 -AP I 2-21 * 6 275 ± 62 <.05des--ser.sup.1, ser.sup.2 -AP I 3-21des--ser.sup.21 -AP 1-20 8 235 ± 70 NSAtriopeptin II 1-23 3 1869 ± 114 <.005Atriopeptin III 1-24 6 1241 ± 261 <.01______________________________________ Table 4. Comparative effectiveness of the atrial peptides as natriureticdiuretic substances in vivo. The U.sub.Na V data is presented as % of the stable baseline values obtained immediately prior to injectio of the peptide. The baseline U.sub.Na V was 0.21 ± 0.05μ equivalents/min. *Mixture of des--ser.sup.1 -AP I and des--ser.sup.1, ser.sup.2 -AP I. NS = not significant
In the isolated perfused rat kidney, atriopeptin II and atriopeptin III produced a concentration dependent renal vasodilation. The peptides which lack the phe-arg C-terminal (i.e., the atriopeptin I family of peptides) were very much less active renal vasodilators.
Various other examples and modifications of the foregoing examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention, and it is intended that all such examples or modifications be included within the scope of the appended claims. Thus, variations in length and composition of the end groups (R 1 or R 2 ) of the peptides or in the individual amino acids of the peptides which do not adversely or detrimentally affect their biologic activity as defined herein are included within the scope of the appended claims.
|
Novel atrial peptides having useful natriuretic activity are disclosed with the following amino acid sequence:
R.sub.1
-cys-phe-gly-gly-arg-ile-asp-arg-ile-gly-ala-gln-ser-gly-leu-gly-cys-asn-R 2
wherein
R 1 =H, ser, ser-ser, and
R 2 =OH, ser, ser-phe-arg, ser-phe-arg-tyr,
or the physiologically acceptable salts, esters or amides thereof.
| 8
|
CROSS-REFERENCE TO RELATED CO-PENDING APPLICATION
This application is a continuation-in-part of U.S. Pat. application Ser. No. 477,861, filed June 10, 1974; the applicant is David H. Blount, M.D.
BACKGROUND OF THE INVENTION
This invention relates to a process for the producion of an aqueous solution of silicoformic acid by adding the silicoformic acid to an aqueous solution containing an alkali metal hydroxide or an alkali metal salt of a weak acid; the silicoformic acid goes into solution rapidly when the dilute alkali solution is heated to 60°-100° C.
The silicoformic acid may be produced by the chemical reaction of a dry alkaline metal metasilicate with a mineral acid, or a hydrogen salt. Silicoformic acid, also known, as monosilanic acid, may be produced by other methods such as those disclosed in U.S. Pat. No. 3,674,430.
Silicoformic acid aqueous solutions may be used as coating agents and adhesives, as a filler in elastomers, resins, molding powders and pigments, as a vehicle for insecticides and aromatics, in the polymerization of many plastics, elastomers and natural products. Silicoformic acid aqueous solution may be mixed with emulsions of poly(vinyl chloride), polyacrylate, polymethacrylate, polymethylmethacrylate, polyacrylonitrile, polystyrene, poly(vinyl alcohol), natural proteins, polyamides, sodium cellulose and other organic compounds to be used as coating agents, adhesives and molding powders.
Silicoformic acid in an aqueous solution may be mixed with aqueous emulsions of organic polymers, natural polymers, rubber latex and natural proteins, then neutralized to a pH of about 8-9 by an acetic compound; the silicoformic acid will gel and form a finely dispersed filler. Silicoformic acid in an aqueous solution, may be co-polymerized with many organic compounds by a peroxide.
An alkali aqueous solution may be added to an acetic solution with a pH below 5.5; it will remain in solution for several hours, then slowly gel. The acetic solution may be mineral acids or organic acids which are water soluble.
SUMMARY OF THE INVENTION
I have discovered that silicoformic acid is soluble in a dilute alkali aqueous solution containing an alkali metal hydroxide or an alkali metal salt of a weak acid. The rapidity by which silicoformic acid goes into solution is increased by elevating the temperature; at 60°-100° C it rapidly goes into solution. The most useful alkali metal hydroxides are sodium hydroxide and potassium hydroxide. The most useful alkali metal salts are sodium silicate and sodium silicoformate, but many other alkali metal salts of weak acids may be used such as potassium silicate, potassium silicoformate, sodium polyacrylate, potassium polyacrylate, sodium polymethacrylate and potassium polymethacrylate.
Silicoformic acid is also soluble in organic solutions which contain an alkali metal hydroxide such as alcohols, glycerols and glycols.
DETAILED DESCRIPTION OF THE INVENTION
The method of this invention is to add silicoformic acid to a warm dilute alkali aqueous solution while agitating until the silicoformic acid will not go into solution any more. The undissolved silicoformic acid settles to the bottom, and the aqueous solution of silicoformic acid is removed. When a sodium hydroxide aqueous solution is used, silicoformic acid will go into solution until the ratio of silicoformic acid and sodium hydroxide is about 5:1. Sodium hydroxide is the preferred alkali metal hydroxide. Sodium metasilicate is the preferred alkali metal salt of a weak acid.
DESCRIPTION OF PREFERRED EMBODIMENTS
My invention will be illustrated in greater detail in the following Examples which describe various preferred embodiments of the process of this invention. These Examples are merely illustrative of my novel processes and do not limit the procedures which may be used in the production of my novel aqueous solution of silicoformic acid. Parts and percentages are by weight unless otherwise indicated.
EXAMPLE I
About 3 parts by weight of sodium hydroxide and about 14 parts by weight of silicoformic acid are added to about 20 parts by weight of water; the mixture is then heated to about 80°-100° C while stirring, and the silicoformic acid goes into solution in about 10-20 minutes, thereby producing a clear thick aqueous solution of silicoformic acid. The said solution may be diluted with water to the desired concentration.
EXAMPLE II
About 2 parts by weight of dry sodium metasilicate and about 3 parts by weight of silicoformic acid are added to about 20 parts by weight of water; the mixture is then heated to about 60°-100° C while stirring, and the silicoformic acid goes into solution rapidly, thereby producing a clear aqueous solution of silicoformic acid. The said solution may be further diluted with water if desired.
EXAMPLE III
About 10 parts by weight of silicoformic acid and about 4 parts by weight of sodium silicoformate are added to about 50 parts by weight of water; the said mixture is heated to about 50°-90° C, and the silicoformic acid goes into solution in about 10-20 minutes, thereby producing a clear aqueous solution of silicoformic acid.
EXAMPLE IV
About 4 parts by weight of silicoformic acid and about 1 part by weight of potassium hydroxide are added to about 10 parts by weight of water; the mixture is agitated, and the silicoformic acid slowly goes into solution, thereby producing a clear, thick aqueous solution of silicoformic acid. The said solution may be diluted with water to the desired concentration.
EXAMPLE V
About 4 parts by weight of granular silicoformic acid and about 1 part by weight of sodium hydroxide are added to about 30 parts by weight of water at a temperature of 25°-35° C. The said mixture is stirred, and the silicoformic acid goes into solution in about 2-4 hours.
Although certain specific preferred ingredients and conditions are described in conjunction with the above detailed description of the Invention and Examples, these may be varied and other ingredients may be used where suitable, with similar results. Other applications, modifications and ramifications of this invention will occur to those skilled in the art upon reading this disclosure. These are intended to be included within the scope of this invention, as defined in the appended claims.
|
Silicoformic acid granules will go into solution when mixed in a dilute aqueous solution of an alkali metal hydroxide or an alkali metal salt of a weak acid.
| 2
|
TECHNICAL FIELD
This invention relates to ring transmission systems and, more particularly, to bidirectional multiplex section-switched ring transmission systems.
BACKGROUND OF THE INVENTION
In prior known bidirectional multiplex section-switched self-healing ring transmission systems, bridging and switching, in the presence of a fault, was restricted to switching ring nodes immediately adjacent to the fault. A problem with such an arrangement, in long distance networks, is that the restoration path is extremely long. The extremely long restoration path is a consequence of the fact that only the ring nodes adjacent to the fault are allowed to bridge, switch and loop the restored traffic. In certain applications, for examples, transoceanic bidirectional multiplex section-switched ring transmission systems, the length of the restoration path would be extremely long, causing long delays and degraded system performance. The extremely long length of the restoration path results from the looping which causes it to traverse the ocean three times for particular fault conditions. It is the looping aspect of the restored path that causes the system impairment. The long delays and degraded service is extremely undesirable.
SUMMARY OF THE INVENTION
The problems resulting from prior bidirectional multiplex section-switched ring transmission system restoration techniques are overcome, in accordance with the principles of the invention, by eliminating looping in the ring nodes immediately adjacent to the failure and by, additionally, distributing switching of the paths to be protected to ring nodes other than those immediately adjacent to the failure. This is realized by provisioning each node with a map of its traffic pattern (all active tributaries), the identities of all the ring nodes and the relative position of each ring node in the bidirectional multiplex section-switched ring transmission system and allowing the ring node, if it has communications traffic affected by the failure, to bridge and switch directly to and from the protection path.
Technical advantages of this invention are: that misconnections of communications circuits, previously resulting in squelching of the circuits, are eliminated; the resulting restored paths are shorter; and, since, only affected communications traffic is bridged and switched, only portions of the protection facility are used, so-called part-time service can be re-established on the protection facility, where applicable.
BRIEF DESCRIPTION OF THE DRAWING In the drawing:
FIG. 1 shows, in simplified block diagram form, bidirectional multiplex section-switched ring transmission system 100 including ring nodes 101 through 104 incorporating the invention;
FIG. 2 shows, in simplified block diagram form, details of a ring node including an embodiment of the invention;
FIG. 3 shows, in simplified block diagram form, details of a receiver used in the ring node of FIG. 2;
FIG. 4 shows, in simplified block diagram form, details of a transmitter used in the ring node of FIG. 2;
FIG. 5 is an exemplary ring node ID map included in memory of the controller of FIG. 2;
FIG. 6 is an exemplary ring node communications tributary traffic pattern table also included in memory of the controller of FIG. 2 for ring node 104;
FIG. 7 is an exemplary ring node communications tributary traffic pattern table also included in memory of the controller of FIG. 2 for ring node 102;
FIG. 8 is a flow chart illustrating the bridge and switch operation of the controller of FIG. 2;
FIG. 9 is a table illustrating the switch request message (K1) and switch acknowledgement message (K2) transmission for ring nodes 101 through 104 for an idle condition of the bidirectional multiplex section-switched ring transmission system 100;
FIG. 10 is a table illustrating the initial switch request message (K1) and switch acknowledgement message (K2) transmission for ring nodes 101 through 104 for a complete fiber cut fault between ring nodes 101 and 104 bidirectional multiplex section-switched ring transmission system 100;
FIG. 11 is a table illustrating the switch request message (K1) and switch acknowledgement message (K2) transmission resulting in the communication tributary traffic pattern in bidirectional multiplex section-switched ring transmission system 100 shown in FIG. 12 by employing the invention; and
FIG. 12 shows, in simplified block diagram form, the communications tributary traffic pattern resulting in bidirectional multiplex section-switched ring transmission system 100 by employing the principles of the invention for a fault between ring nodes 101 and 104.
DETAILED DESCRIPTION
FIG. 1 shows, in simplified form, bidirectional multiplex section-switched ring transmission system 100, which for brevity and clarity of exposition is shown as including only ring nodes 101 through 104, each incorporating an embodiment of the invention. It will be apparent that additional or fewer ring nodes and different orientation of ring nodes may be employed, as desired. Ring nodes 101 through 104 are interconnected by transmission path 110, including service path 110-S and protection path 110-P, in a counter-clockwise direction, and by transmission path 120, including service path 120-S and protection path 120-P, in a clockwise direction. In this example, transmission paths 110 and 120 are each comprised of two (2) optical fibers. It will be apparent, however, and each of transmission paths 110 and 120 could be comprised of a single optical fiber. That is, bidirectional multiplex section-switched ring transmission system 100 could be either a two (2) optical fiber or a four (4) optical fiber system. In a two (2) optical fiber system, each of the fibers in transmission paths 110 and 120 includes service bandwidth and protection bandwidth. In the four (4) optical fiber system shown, each of transmission paths 110 and 120 includes an optical fiber for service bandwidth and a separate optical fiber for protection bandwidth. Such bidirectional multiplex section-switched ring transmission systems are known. In this example, transmission of digital signals in the CCITT Synchronous Digital Hierarchy (SDH) digital signal format is assumed. However, it will be apparent that the invention is equally applicable to other digital signal formats, for example, the ANSI SONET digital signal format. In this example, it is assumed that an optical STM-N SDH digital signal format is being utilized for transmission over transmission paths 110 and 120. In one example, N=16. Details of the SDH digital signal formats are described in CCITT Recommendations G.707, G.708 and G.709 entitled "Synchronous Digital Hierarchy Bit Rates", "Network Node Interface For The Synchronous Digital Hierarchy" and "Synchronous Multiplex Structure", respectively.
It is noted that requests and acknowledgments for protection switch action are transmitted in an Automatic Protection Switch (APS) channel in the SDH multiplex section overhead accompanying the protection paths 110-P and 120-P on each of transmission paths 110 and 120. The APS channel, in the SDH format, comprises the K1 and K2 bytes in the SDH overhead of each of protection paths 110-P and 120-P. The K1 byte indicates a request of a communications tributary for switch action. The first four (4) bits of the K1 byte indicate the switch request priority and the last four (4) bits indicate the ring node identification (ID) of the destination ring node. The K2 byte indicates an acknowledgment of the requested protection switch action. The first four (4) bits of the K2 byte indicate the ring node ID of the source ring node and the last 4 bits indicate the action taken. For purposes of this description, a "communications circuit" is considered to be a AU-4 SDH digital signal having its entry and exit points on the ring.
Each of ring nodes 101 through 104 comprises an add-drop multiplexer (ADM). Such add-drop multiplexer arrangements are known. For generic requirements of a SDH based ADM see CCITT Recommendation G.782. In this example, the ADM operates in a transmission sense to pass, i.e., express, signals through the ring node, to add signals at the ring node, to drop signals at the ring node, and to bridge and switch signals, in accordance with the principles of the invention, during a protection switch at the ring node. Note that, in accordance with the principles of the invention, there is no looping of the affected signals in ring nodes adjacent the failure, as was required in prior bidirectional multiplex section-switched ring transmission systems.
FIG. 2 shows, in simplified block diagram form, details of ring nodes 101 through 104, including an embodiment of the invention. In this example, a west (W)-to-east (E) digital signal transmission direction is assumed in the service path 110-S and the protection path 110-P on transmission path 110. It will be apparent that operation of the ring node and the ADM therein would be similar for an east (E)-to-west (W) digital signal transmission direction in the service path 120-S and the protection path 120-P on transmission path 120. Specifically, shown are service path 110-S and protection path 110-P entering the ring node from the west (W) and supplying STM-N SDH optical signals to receiver 201-S and receiver 201-P, respectively, where N is, for example, 16. Similarly, shown are service path 120-S and protection path 120-P entering the ring node from the east (E) and supplying STM-N SDH optical signals to receiver 202-S and receiver 202-P, respectively, where N is, for example, 16. Details of receivers 201 and 202 are identical, and are shown in FIG. 3, to be described below.
The SDH STM-N optical signals exit the ring node on service path 110-S as an output from transmitter 203-S, on service path 120-S as an output from transmitter 204-S, on protection path 110-P as an output from transmitter 203-P and on protection path 120-P as an output from transmitter 204-P. Details of transmitters 203 and 204 are identical and are shown in FIG.4, to be described below.
AU-4 SDH output signals from receiver 201-S are routed under control of controller 210 either to transmitter 203-S, i.e., expressed through to service path 110-S, to interface 206-S to be dropped, also to interface 206-S for protection switching to interface 206-P where it will be dropped or to transmitter 203-P to be supplied to protection path 110-P. In similar fashion, AU-4 SDH output signals from receiver 202-S are routed under control of controller 210 either to transmitter 204-S, i.e., expressed through to service path 120-S, to interface 207-S to be dropped, also to interface 206-S for protection switching to interface 206-P where it will be dropped or to transmitter 204-P to be supplied to protection path 120-P. Note that there is no looping back of the AU-4 SDH signals to either protection path 110-P or protection path 120-P, in accordance with the invention. The AU-4 signals from receiver 201-P are supplied either to transmitter 203-P, i.e., expressed through to protection path 110-P, to interface 206-S to be dropped or to transmitter 203-S to be supplied to service path 110-S. In similar fashion, AU-4 signals from receiver 202-P are routed under control of controller 210 either to transmitter 204-P, i.e., expressed through to protection path 120-P, to interface 207-S to be dropped or to transmitter 204-S to be supplied to service path 120-S. Again, note that there is no looping back of the AU-4 SDH signals to either service path 110-S or service path 120-S, in accordance with the invention. AU-4 SDH signals being added and dropped via interface 206-S can be bridged to transmitter 203-P and, hence, protection path 110-P and can be switched from receiver 202-P and, hence, from protection path 120-P, all under control of controller 210. Similarly, AU-4 SDH signals being added and dropped via interface 207-S can be bridged to transmitter 204-P and, hence, protection path 120-P and can be switched from receiver 201-P and, hence, from protection path 110-P, all under control of controller 210.
As indicated above, eliminating the looping of signals in ring nodes adjacent the failure, in accordance with the principles of the invention, minimizes the length of the restored path and, additionally, eliminates communications circuit misconnections which, in turn, eliminates squelching of those circuits.
Interfaces 206-S, 206-P, 207-S and 207-P are employed to interface to particular duplex links 216-S, 216-P, 217-S and 217, respectively, and could include any desired arrangement. For example, interfaces 206 and 207 could include a CEPT-4 digital signal interface to a DSX, a STM-1E (electrical) SDH digital signal interfacing to a DSX, an optical extension interface to an STM-1 SDH optical signal or the like. Such interface arrangements are known. Controller 210 controls the adding and dropping of the signals via interfaces 206 and 207, as well as, the direct bridging and switching of the AU-4 tributaries being added and dropped to and from protection paths 110-P and 120-P. Controller 210 also monitors the status of interfaces 206 and 207 and the digital signals supplied thereto via the control bus arrangement. Specifically, controller 210 monitors interfaces 206 and 207 for loss-of-signal, loss-of-frame, coding violations and the like, i.e., a signal failure condition.
Controller 210 operates to effect the bridging and switching of communications tributaries at ring nodes other than those adjacent the failure, if necessary, in accordance with the principles of the invention. Controller 210 communicates with receivers 201 and 202, transmitters 203 and 204 and interfaces 206 and 207 via a control bus arrangement. Specifically, controller 210 monitors the incoming digital signals to determine loss-of-signal, SDH format K bytes and the like. Additionally, controller 210 causes the insertion of appropriate K byte messages for protection switching purposes, examples of which are described below. To realize the desired bridging and switching of the communications tributaries, controller 210 is advantageously provisioned via bus 212 with the identities (IDs) of of all the communications tributaries passing through the ring node, as well as, those communications tributaries being added and/or dropped at the ring node, the identifies of all the ring nodes in bidirectional multiplex section-switched ring 100 and the positions of the ring nodes in bidirectional multiplex section-switched ring 100. The bridging and switching of communications tributaries under control of controller 210 to effect the invention is described below.
FIG. 3 shows, in simplified form, details of receivers 201 and 202 of FIG. 2. The receiver includes an optical/electrical (O/E) interface 301, demultiplexer (DEMUX) 302 and driver and router 303. An STM-N SDH optical signal is supplied to O/E 301 which converts it to an electrical STM-N signal. In turn, DEMUX 302 demultiplexes the STM-N signal, in known fashion, to obtain up to N AUG SDH signal, namely, AUG (1) through AUG (N). Again, in this example, N=16. The AUG (1) through AUG (N) signals are supplied to driver and router 303 where they are routed under control of controller 210 via the control bus as AU-4 (1) through AU-4 (M) SDH signals. As indicated above, each STM-N signal can include N AUG tributaries, in this example. The AU-4 (1) through AU-4 (M) signals are routed under control of controller 210, as described above regarding FIG. 2. DEMUX 302 also removes STM overhead (OH), and supplies the APS channel K bytes to controller 210 via the control bus.
FIG. 4 shows, in simplified form, details of transmitters 203 and 204 of FIG. 2. The transmitter includes select unit 401, multiplexer (MUX) 402 and electrical/optical interface (E/O) 403. The AU-4 (1) through AU-4 (M) signals are supplied to select unit 401 where the particular tributaries AUG (1) through AUG (N) are selected under control of controller 210 to be supplied to MUX 402. Again, in this example, N=16. The AUG tributaries are supplied to MUX 402 where overhead (OH) is added to yield an electrical STM-N SDH signal. In turn E/O interface 403 converts the STM-N into an optical STM-N for transmission on the corresponding fiber transmission path. MUX 402 also inserts appropriate K byte messages under control of controller 210 via the control bus.
FIG. 5 is a ring node map table including the identification (ID) of and relative location of each of ring nodes 101 through 104 in bidirectional multiplex section-switched ring transmission system 100. The ring node IDs are stored in a look-up table which is provisioned via 212 in memory of controller 210. As indicated above, the ring node IDs are 4 bit words and are included in the second 4 bits of the K1 bytes and the first 4 bits of the K2 bytes in the APS channel.
FIG. 6 is illustrative of a table including the identification of the ring node communications traffic, i.e., the active communications tributaries, in a ring node, in this example, ring node 104, for the clockwise (CW) direction and the counter-clockwise (CCW) direction of transmission through ring nodes 101 through 104. The active communications tributaries include those being added, dropped or expressed through ring node 104. The table including the IDs of the active communications tributaries in the ring node are provisioned via 212 in a look-up table in memory of controller 210. Shown in the table of FIG. 6 are the AU-4 tributary identifications, i.e., the AU-4 (#). In this example, the number of AU-4 tributaries can be up to 16. Thus shown, are the AU-4 tributaries (a) and (b) being transmitted in ring node 104 in the clockwise (CW) direction and AU-4 tributaries (c) and (d) being transmitted in the counter-clockwise (CCW) direction. The CW destination for AU-4 tributary (a) is ring node 101. The CW destination for AU-4 tributary (b) is ring node 102. The CCW destination for tributary (c) is ring node 103. Finally, the CCW destination for AU-4 tributary (d) is ring node 102.
FIG. 7 is illustrative of a table including the identification of the ring node communications traffic, i.e., the active communications tributaries, in a ring node, in this example, ring node 102, for the clockwise (CW) direction and the counter-clockwise (CCW) direction of transmission through ring nodes 101 through 104. The active communications tributaries include those being added, dropped or expressed through ring node 102. The table including the IDs of the active communications tributaries in the ring node are provisioned via 212 in a look-up table in memory of controller 210. Shown in the table of FIG. 7 are the AU-4 tributary identifications, i.e., the AU-4 (#). In this example, the number of AU-4 tributaries can be up to 16. Thus shown, are the AU-4 tributaries (a), (b) and (d) being transmitted in ring node 102 in the clockwise (CW) direction and AU-4 tributaries (b) and (e) being transmitted in the counter-clockwise (CCW) direction. The CW destination for AU-4 tributary (a) is ring node 103. The CW destination for AU-4 tributary (b) is ring node 103. The CW destination for tributary (d) is ring node 104. The CCW destination for tributary (b) is ring node 104. Finally, the CCW destination for AU-4 tributary (e) is ring node 101.
FIG. 8 is a flow chart illustrating the operation of controller 210 in controlling the operation of the ring nodes in order to effect the bridging and switching of tributary traffic paths in the presence of a failure, in accordance with the invention. It should be noted that all so-called part-time service being transported on the protection path is preempted upon detection of the failure. Specifically, the process is entered via step 801. Then, operational block 802 causes the K bytes of an incoming STM-N signal to be observed. Then, conditional branch point 803 tests to determine if the observed K bytes indicate a change from an idle state. If no change from the idle state is indicated control is returned to step 802. If the observed K bytes indicate switch request messages have been received, conditional branch point 804 tests to determine if communications traffic for this ring node is affected by the switch request. If the test result is NO, control is returned to step 802. If the test result in step 804 is YES, operational block 805 directly bridges and switches the affected tributary traffic paths from and to the appropriate protection path. Thereafter, the process is ended in step 806.
FIG. 9 is a table illustrating the switch request message (K1) and switch acknowledgement message (K2) transmission for ring nodes 101 through 104 for an idle condition of the bidirectional multiplex section-switched ring transmission system 100. As indicated above, the K1 byte transports any switch request messages in the APS of the appropriate protection path. The K2 byte transports acknowledgement messages. In the idle state, i.e., no switch being requested, the K1 byte includes an idle code in the first four (4) and the destination ID in the second four (4) bits. The K2 byte includes the source ID in the first four (4) bits, short path code bit in the fifth (5) bit and signaling/idle code in the last three (3) bits. Note that the K1 and K2 bytes for each of service paths 110-S and 120-S are transmitted in the APS channel of protection paths 120-P and 110-P, respectively. The particular K1 and K2 byte idle state messages for nodes 101 through 104 employed in bidirectional multiplex section-switched ring transmission system 100 are shown in FIG. 9.
FIG. 10 is a table illustrating the initial switch request message (K1) and switch acknowledgement message (K2) transmission for ring nodes 101 through 104 for a complete fiber cut fault between ring nodes 101 and 104 bidirectional multiplex section-switched ring transmission system 100. Thus, ring nodes 101 and 104 insert switch request messages in the K1 bytes in both protection paths 110-P and 120-P. The switch request message indicates a signal failure and the destination ring node. Additionally, an acknowledgement message is inserted in the K2 bytes of both protection path 110-P and 120-P. The acknowledgement message inserted in path 110-P includes the source 1D, long path bit and signaling/idle. The acknowledgement message inserted in path 120-P includes the source ID, short path bit and signaling/FERF (far end received failure). Ring node 104 inserts similar switch request and acknowledgement messages in the K1 and K2 bytes of paths 11 0-P and 120-P, except the acknowledgement message inserted in path 110-P indicates short path and signaling/FERF and the acknowledgement message inserted in path 120-P indicates long path and signaling/idle. Again, note that the K1 and K2 bytes for each of service paths 110-S and 120-S are transmitted in the APS channel of protection paths 120-P and 110-P, respectively. The particular K1 and K2 byte messages for nodes 101 through 104 employed in bidirectional multiplex section-switched ring transmission system 100 upon initiating a switch are shown in FIG. 10.
FIG. 11 is a table illustrating the switch request message (K1) and switch acknowledgement message (K2) transmission resulting in the communications tributary traffic pattern in bidirectional multiplex section-switched ring transmission system 100 shown in FIG. 12 by employing the invention. Again, ring nodes 101 and 104 insert switch request messages in the K1 bytes in both protection paths 110-P and 120-P. The switch request message indicates a signal failure and the destination ring node. Thus, ring node 101 inserts a switch request message in the K1 byte of the APS in the clockwise (CW) direction in protection path 120-P and in the counter-clockwise (CCW) direction in protection path 110-P. The switch request message indicates a signal failure and identifies ring node 104 as the destination ring node. The K1 byte on protection path 120-P is expressed through ring nodes 102 and 103 and arrives at ring node 104. Since ring node 104 has detected loss-of-signal and the switch request messages includes its identification, it knows that the fault is in the path between ring nodes 101 and 104. Similarly, ring node 104 inserts a switch request message in the K1 byte of the APS in the clockwise (CW) direction in protection path 120-P and in the counter-clockwise (CCW) direction in protection path 110-P. The K1 byte on protection path 110-P is expressed through ring nodes 103 and 102 and arrives at ring node 101. Since ring node 101 has detected loss-of-signal and the switch request messages includes its identification it knows that the fault is in the path between ring nodes 101 and 104. Both of ring nodes 101 and 104 insert acknowledgement messages in the APS K2 byte both protection paths 110-P and 120-P. Again, the K2 acknowledgement message from ring node 101 is expressed through ring nodes 102 and 103 to ring node 104, while the K2 acknowledgement message from ring node 104 is expressed through ring nodes 103 and 102 to ring node 101.
Because of the provisioning of each ring node, in accordance with the invention, each of the ring nodes by observing the K byte messages knows if any communications tributary that is terminated in the ring node is affected by the failure. If so, the ring node will bridge and switch the affected tributary to and from the appropriate protection path, in accordance with the invention.
FIG. 12 shows, in simplified block diagram form, the resulting AU-4 tributary traffic pattern in bidirectional multiplex section-switched ring transmission system 100 by employing the principles of the invention for a fault between ring nodes 101 and 104 for the provisioning as shown in FIGS. 5, 6 and 7. It is noted that all so-called part-time communications traffic being transported on the protection paths 110-P and 120-P must be removed before any protection switching activity. Thus, in ring node 101, STM-1 tributary (a) intended for ring node 104 in the counter-clockwise (CCW) direction is directly bridged and switched to and from protection paths 110-P and 120-P, while STM-1 tributary (e) intended for ring node 102 in the clockwise (CW) direction is unaffected. In ring node 102, STM-1 tributary (b) intended for ring node 104 in the counter-clockwise direction is directly bridged and switched to and from protection paths 110-P and 120-P, while STM-1 tributaries (e) intended for ring node 101 in the CCW direction, (a) and (b) intended for ring node 103 and (d) intended for ring node 104 in the CW direction are unaffected. In ring node 103, STM-1 tributaries (a), (b), and (c) are unaffected. In ring node 104, STM-1 tributaries (a) and (b) intended for ring node 101 and 102, respectively, in the CW direction are directly bridged and switched to and from protection paths 110-P and 120-P, while STM-1 tributaries (c) and (d) intended for ring nodes 103 and 104, respectively, in the CCW direction are unaffected. As indicated above, since the affected STM-1 tributaries are directly bridged and switched to and from the protection paths at its termination ring nodes, which are not necessarily adjacent the failure, looping is eliminated, in accordance with the invention. Additionally, the elimination of looping now frees up portions of the protection paths and so-called part-time communications traffic can be transported over those freed up portions of the protections paths.
The above-described arrangements are, of course, merely illustrative of the application of the principles of the invention. Other arrangements may be devised by those skilled in the art without departing from the spirit or scope of the invention.
|
Long delays in bidirectional multiplex section-switched self-healing ring transmission systems are avoided by eliminating looping of communications signals when restoring them in response to a failure in the ring and by distributing switching of paths to be protected to ring nodes other than those immediately adjacent the failure. This is realized by provisioning each node in the bidirectional multiplex section-switched ring transmission system with a map of its traffic pattern (all active tributaries) and the relative position of each ring node in the ring transmission system, and allowing the ring node, if it has communications traffic affected by the failure, to bridge and switch to and from the protection path.
| 7
|
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority under 35 U.S.C. §§120/121 to U.S. patent application Ser. No. 11/345,637 filed on Jan. 31, 2006, which is a non-provisional of, and claims the benefit of, co-pending, commonly-assigned, U.S. Provisional Patent Application No. 60/649,282 entitled “VARIABLE EXPOSURE FOR COLOR IMAGER,” filed on Feb. 1, 2006, by Yosefin and of U.S. Provisional Patent Application No. 60/649,337 entitled “DUAL EXPOSURE FOR IMAGE SENSOR,” filed on Feb. 1, 2006, by Yaffee, the entire disclosure of each of which is herein incorporated for all purposes.
[0002] This application is related to U.S. patent application Ser. No. 11/345,642 (Attorney Docket No. 040013-004210US) entitled “DUAL EXPOSURE FOR IMAGE SENSOR,” which has issued as U.S. Pat. No. 7,554,588, the entire disclosure of which is herein incorporated for all purposes.
BACKGROUND OF THE INVENTION
[0003] Embodiments of the invention relate generally to image sensors. More specifically, embodiments of the invention relate to increasing the signal to noise ratio (SNR) of image sensors using variable exposure techniques.
[0004] Selecting the proper exposure duration for image sensors, such as CMOS image sensors (CIS), can be difficult. If the selected exposure duration is too long, pixels may become saturated and the resulting image quality may be poor. If the selected exposure duration is too short, pixels values may be below the dynamic threshold and detail may be lost.
[0005] U.S. Pat. No. 5,144,442 (the '442 patent) discloses a method to increase the dynamic range of still images (and of video streams) by acquiring the same scene with multiple exposure periods, then merging the multiple images into a single wide dynamic range image. Conventional techniques to obtain multiple images of the same scene include: using multiple image sensors; and using two sequential image acquisitions, one with a long exposure and one with a short exposure. The first method is expensive, not only because of the need for two image sensors, but also because the two image sensors need to be optically aligned with great precision so that the image of any object in front of the lens will be projected on the same pixel row and column of both image sensors. The second method, using sequential image acquisitions, is cheaper. Because the two acquisitions are not done at the same time, however, the resulting image is susceptible to motion artifacts. Other conventional techniques (e.g. U.S. Pat. No. 5,959,696) offer means to correct for such motion artifacts, but those methods are complex and expensive.
[0006] In view of the foregoing, improved methods are needed to increase the dynamic range of image sensors.
BRIEF SUMMARY OF THE INVENTION
[0007] Embodiments of the invention provide a method of capturing an image of a scene using an image capture device having an array of pixels. The array of pixels includes pixels of different colors. The method includes, for a first duration, capturing a first portion of the scene with a first plurality of the pixels of a first color, and for a second duration, capturing a second portion of the scene with a second plurality of the pixels of a second color. The first and second durations are different and the first and second durations are chosen, at least in part, to improve the signal to noise ratio of the image capture device.
[0008] In some embodiments the method includes, for a third duration, capturing a third portion of the scene with a third plurality of the pixels of a third color. The first, second, and third colors may be red, green, and blue. The first, second, and third durations may be different. The array of pixels may be a Bayer grid. The image capture device may be a CMOS image sensor. The first color may be red, the second color may be green, and the third color may be blue and two of the three durations may be the same.
[0009] In other embodiments, an image capture device, includes an array of pixels having pixels of different colors and circuitry configured to control the operation of the pixels to thereby capture an image of a scene. In doing so, the control circuitry causes the pixels to, for a first duration, capture a first portion of the scene with a first plurality of the pixels of a first color and, for a second duration, capture a second portion of the scene with a second plurality of the pixels of a second color.
[0010] In some embodiments, the first and second durations are different. The circuitry may be further configured to control the operation of the pixels to thereby capture an image of a scene by, for a third duration, capture a third portion of the scene with a third plurality of the pixels of a third color. The first, second, and third colors may be red, green, and blue. The first, second, and third durations may be different. The array of pixels may be a Bayer grid. The image capture device may be a CMOS image sensor. The first color may be red, the second color may be green, and the third color may be blue, and two of the three durations may be the same. The first, second, and third durations may be chosen, at least in part, to improve the signal to noise ratio of the image capture device.
[0011] In still other embodiments, an image capture device includes an array of pixels having pixels of different colors and circuitry configured to control the operation of the pixels to thereby capture an image of a scene. The circuitry includes means for capturing a first portion of the scene for a first duration with a first plurality of the pixels of a first color, means for capturing a second portion of the scene for a second duration with a second plurality of the pixels of a second color, means for capturing a third portion of the scene for a third duration with a third plurality of the pixels of a third color. The first and second durations are different.
[0012] In some embodiments the first, second, and third colors are red, green, and blue. The first, second, and third durations may be different. The array of pixels may be a Bayer grid. The image capture device may be a CMOS image sensor. The first color may be red, the second color may be green, and the third color may be blue and two of the three durations may be the same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings wherein like reference numerals are used throughout the several drawings to refer to similar components. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[0014] FIG. 1 illustrates timing waveforms a dual exposure image capture device according to embodiments of the invention.
[0015] FIG. 2 illustrates a functional block diagram of a circuit to accomplish the dual exposure embodiment of FIG. 1 .
[0016] FIG. 3 illustrates a functional block diagram of the intelligent interpolator of FIG. 2 .
[0017] FIG. 4 illustrates an energy profile for an image captured by a conventional image capture device.
[0018] FIG. 5 illustrates an energy profile for an image captured by an image capture device according to embodiments of the invention.
[0019] FIG. 6 illustrates an exemplary 3-T pixel circuit according to embodiments of the invention.
[0020] FIG. 7 illustrates an exemplary pixel array for use with the circuit of FIG. 6 .
[0021] FIG. 8 illustrates timing waveforms for the pixel array of FIG. 7 .
[0022] FIG. 9 illustrates an exemplary 4-T pixel circuit according to embodiments of the invention.
[0023] FIG. 10 illustrates an exemplary 2×2 array employing transistor sharing between two pixels according to embodiments of the invention.
[0024] FIG. 11 illustrates timing waveforms for the pixel array of FIG. 10 .
[0025] FIG. 12 illustrates an exemplary 2×2 array employing transistor sharing among four pixels according to embodiments of the invention.
[0026] FIG. 13 illustrates timing waveforms for the pixel array of FIG. 12 .
[0027] FIG. 14 illustrates an exemplary 2×4 pixel array having sharing of pixels and transfer lines according to embodiments of the invention.
[0028] FIG. 15 illustrates timing waveforms for the pixel array of FIG. 14 .
[0029] FIG. 16 illustrates an energy profile for an image captured by an image capture device using the pixel array of FIG. 14 .
DETAILED DESCRIPTION OF THE INVENTION
[0030] The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention. It is to be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.
[0031] Specific details are given in the following description to provide a thorough understanding of the embodiments. It will be understood by one of ordinary skill in the art, however, that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
[0032] In the ensuing embodiments, methods and circuits to improve the dynamic range of image sensors are disclosed and claimed. Such embodiments reduce the signal to noise ratio (SNR) and/or prevent saturation of CMOS image sensors (CIS). Disclosed embodiments do not require multiple image sensors and do not require capturing multiple images at different times. In some embodiments, alternating short and long exposure durations are applied for every other row for an image array. In other embodiments, alternating short and long exposure durations are applied for every other row pair. In still other embodiments, different exposure durations are used for different colors and/or different color groups. Exemplary circuits to provide the timing waveforms to implement some embodiments are disclosed and claimed. An exemplary algorithm to merge information from alternating exposure pairs of rows to a seamless wide dynamic range picture or video stream is also disclosed.
[0033] A CIS-based camera typically adjusts the exposure level based on the brightness of the image to be captured. If the exposure is too long, some of the pixels—in particular those in the brighter areas of the image—tend to reach saturation—a point where they can no longer integrate light energy. Image regions with such over-exposed pixels are referred to as saturated regions, and pictures with large saturated regions are considered to be of low quality. On the other hand, when the exposure time is too short, the energy accumulated in some of the pixels—in particular those in the darker areas of the image—will be low relative to the energy of the inherent noise, resulting in poor SNR and, again, poor image quality.
[0034] Real-time software programs are used with CIS-based cameras. This software measures the energy levels of the pixels, extracts basic statistics from the measurement results, and then changes the exposure time accordingly so as to achieve an optimum picture. The software ideally converges to an exposure duration that is long enough so that a minimal number of pixels in dark area will exhibit poor SNR, but is short enough so that few—if any—pixels will be in saturation. Such real time software programs are generally referred to as “Auto-Exposure” functions.
Dual Exposure Embodiments
[0035] In the immediately ensuing embodiments, exposure durations are different for different rows. In some embodiments, the exposure durations are alternated between short and long after every pair of rows. Such embodiments are particularly useful for image arrays that employ Bayer grids. The color pattern of the pixels in a Bayer grid has a repetition period of two rows. Using different exposures for all odd rows on one hand and all even rows on the other hand may result in the loss of color information. Hence, in some embodiments with a Bayer grid, exposure durations are alternated every two rows.
[0036] FIG. 1 illustrates a timing diagram 100 for the top eight rows 102 of a CMOS image sensor (CIS) according to embodiments of the current invention. In this timing diagram, rows n ( 102 - 0 ), n+1 ( 102 - 1 ), n+4 ( 102 - 4 ), n+5 ( 102 - 5 ), . . . have a long exposure setting, while rows n+2 ( 102 - 2 ), n+3 ( 102 - 3 ), n+6 ( 102 - 6 ), n+7 ( 102 - 7 ) . . . have a short exposure setting. For each row, the exposure period is the period of time from the moment the row is Reset (RST) to the moment that the row is Read (RD).
[0037] The ratio of long exposure duration to short exposure duration need not be a whole number. The short exposure duration may be any fraction of the long exposure duration and may be optimized for different environments. The ratio may be user selectable or may be determined automatically.
[0038] Those skilled in the art will appreciate that the timing diagram of FIG. 1 corresponds to a “rolling shutter” image capture system. Those skilled in the art will also appreciate that other embodiments may be employed for use with “global shutter,” or “snapshot shutter,” systems wherein the exposure periods are initiated electronically (by resetting the short and long exposure rows at different times) and mechanically ending all the exposures at the same time. Rows are then read sequentially as shown and processed as will be described hereinafter.
[0039] Having described an exemplary timing diagram, attention is directed to FIG. 2 , which illustrates an exemplary circuit 200 according to embodiments of the invention. The timing diagram of FIG. 1 , in which alternating row pairs have different exposure durations, may be implemented in the circuit of FIG. 2 .
[0040] The circuit 200 includes a pixel array 202 , a row decoder 204 , a read counter 206 , a reset multiplexer 208 , and a readout analog-to-digital converter 210 . The pixel array 202 includes a number of CMOS sensors arranged into rows. The row decoder 204 addresses rows to be read in response to signals from the read counter 206 and reset multiplexer 208 . The read counter 206 advances through the rows sequentially. The reset multiplexer 208 multiplexes logic signals from a long exposure counter 212 , a short exposure counter 214 , and a toggle circuit 216 . Those skilled in the art will appreciate that the reset multiplexer 208 may be replaced with a reset counter to implement prior art algorithms.
[0041] The long exposure counter 212 advances the address of the row to be reset for those rows which are to have long exposure. The short exposure counter 214 advances the address of the row to be reset for those rows which are to have short exposure. The toggle circuit 216 toggles the reset multiplexer 208 between the long exposure counter 212 and the short exposure counter 214 every two rows.
[0042] The readout analog-to-digital converter 210 reads the voltages of CMOS sensors in the addressed row, optionally subtracts the pre-sampled Reset level and/or the Black Level, and coverts the output to digital form. The digital output is then fed into an intelligent interpolator 218 that combines the short and long exposure rows to form a wide-dynamic range image. The function of the intelligent interpolator 218 is described immediately hereinafter.
[0043] FIG. 3 depicts the operation of the intelligent interpolator 218 logically. It includes two, two-row buffers DL 1 ( 301 ) and DL 2 ( 302 ). Rows are read serially into DL 1 , then through to DL 2 . Those skilled in the art will appreciate that the interpolator operates on one pixel at a time. If the “current row” is defined to be the row being output from DL 1 , the interpolation functions as follows.
[0044] As each pixel value is clocked out of DL 2 , it value is added to the value of the pixel being clocked from the A-to-D converter by the adder 304 . The result is divided by 2 by the divider 306 to produce an average value. This operation creates an interpolated pixel value using the values of the pixels in the rows two above and two below the current row. This interpolated row is herein referred to as a “neighborhood row.” A selection is then made between the current pixel of the neighborhood row and the current pixel of the current row that is being output from DL 1 . It should be apparent that the exposure duration of the current row will always be different than the exposure duration of the neighborhood row. When the exposure duration of the current row is short, the neighborhood row exposure duration will be long, and vice versa.
[0045] If the current row is a short exposure row and the current pixel value is above a predetermined threshold (i.e., above the noise level), then interpolation is not needed. The merger block 308 sets the value of W 1 to be α (alpha) and sets the value of W 2 to be 0, wherein α (alpha) is a scale factor. As a result, the output of the first multiplier 310 is the value of the current pixel of the current row multiplied by the scale factor and the output of the second multiplier 312 is 0. The values are summed by the adder 314 , which outputs the high dynamic range output.
[0046] The scale factor α (alpha) is the ratio of the long exposure duration to the short exposure duration. For example, if the long exposure duration is 100 ms and the short exposure duration is 50 ms, then the scale factor is 2. Hence, when the exposure duration of the current row is short and the current pixel value is above the dynamic threshold, thus not requiring interpolation, the pixel value of the current row is used, but the value is scaled up to be on par with the long exposure duration rows.
[0047] If the current row is a short exposure row and the current pixel value is below the predetermined threshold, then interpolation is needed. The merger block 308 sets the value of W 1 to be 0 and sets the value of W 2 to be 1. The high dynamic range output for the current pixel then becomes the neighborhood row pixel value.
[0048] When the current row is a long exposure duration row and the current pixel value is not saturated, then interpolation is not needed. The merger block 308 sets W 1 to be 1 and sets W 2 to be 0. The high dynamic range output for the current pixel then remains the current pixel value.
[0049] If the current row is a long exposure duration row and the current pixel value is saturated, then interpolation is needed. The merger block 308 sets W 1 to be 0 and sets W 2 to be α. The high dynamic range output becomes the value of the neighborhood row pixel, which is a short duration value, scaled up by the scale factor.
[0050] A nearly identical interpolator may be used to implement systems wherein the exposure duration is alternated every other row, rather than every two rows. The row buffers DL 1 and DL 2 need only be shortened to buffer one row at a time. Those skilled in the art will appreciate that similar interpolators may implement methods wherein exposure durations vary according to other patterns.
[0051] The foregoing embodiments change the exposure duration for various rows of an image sensing array. Other embodiments may change the exposure time for portions of rows or even individual pixels. Any number of exposure times could be used for a particular scan of the imaging array in various embodiments. Several such embodiments are described hereinafter.
Variable Exposure Durations Based on Pixel Color
[0052] In the immediately ensuing embodiments, methods and circuits to improve the signal to noise ratio (SNR) of color CMOS image sensors (CIS) are disclosed. In some embodiments, SNR improvement is achieved by adjusting the exposure time for each color component separately, avoiding the situation where, due to high energy level for one of the color components in the image, the exposure time to all color components is short, which could yield a low SNR. In other embodiments, two separate exposure controls are used, one for the Green color component and the other common for the Red and the Blue components. Any color grouping may be used in other embodiments.
[0053] Typical CIS-based cameras use a color filter array (CFA). Under normal lighting conditions, the energy response is not symmetrical with respect to the CFA colors. Specifically, the Green component typically has much more energy than the Red or the Blue components. As a result, Auto-Exposure software typically limits the exposure to the point where Green pixels reach saturation and, consequently, the Red and the Blue pixels have a relatively short exposure and exhibit poor SNR. This situation is illustrated for a typical image at FIG. 4 .
[0054] Referring to FIG. 4 , suppose the relative strengths of the Green, Blue and Red components are normally distributed around the values of 130, 60 and 40 (out of 256 full scale levels), respectively. The exposure setting cannot be further increased since some of the Green pixels are close to or at 255—the saturation level. Suppose further that the RMS of the noise is 10 levels—designated by the region 406 .
[0055] As can be seen with reference to FIG. 4 , the SNR for the green pixels at the peak is 20*log(130/10)=22.3 dB. However, for the peak value of the blue pixels, which is around level 60, the SNR is 20*log(60/20)=15.6 dB, and for the peak value of the red pixels around level 40, the SNR is only 20*log(40/10)=12 dB.
[0056] A CIS built according to one embodiment of the present invention has different exposure times for one or more of the color components. For example, each color component in the CIS array could have a separate exposure time control. FIG. 5 illustrates the energy profile for such an embodiment.
[0057] Referring to FIG. 5 , an energy profile is illustrated for a CIS embodiment that has different exposure times for each color component. According to this embodiment, the three color components have similar distributions. If this were the same captured image whose energy profile is depicted in FIG. 4 , it is apparent that the Red and Blue exposure times have been increased so as to approach saturation. The SNR for the peak value of all three components is, therefore, about 22.3 dB, a significant improvement for both the Red and Blue components.
[0000] 3- and 4-Transistor Pixel Active Pixel Sensor Embodiments with No Transistor Sharing
[0058] FIG. 6 illustrates a first exemplary circuit for implementing an embodiment that results in the energy profile of FIG. 5 . FIG. 6 illustrates a single, 3-transistor (3-T) pixel 600 having transistors 602 , 604 , and 606 . The first transistor 602 receives a reset pulse, which begins charging of a photo-diode 608 (the n + -p − junction) to an initial high level. Following release of the reset pulse, the photo-diode starts the exposure period, the period when the pixel integrates light energy. The integration ends when the voltage on the diode is read to the column bus, through the transistor 604 , a source follower transistor, and through the transistor 606 , a row select transistor.
[0059] FIG. 7 illustrates a 4×4 portion of a pixel array using a Bayer Grid. This embodiment uses the circuit of FIG. 6 , although other appropriate circuits may be used. The rows are identified starting with row n at the top and ending with row n+3 at the bottom (column numbers are not depicted). Reset inputs of the individual pixels are shown and are identified as “reset” followed by a letter indicating the color being reset for the row. Every color component in a row of pixels has a dedicated reset line to every pixel of that color in the row. Hence, each row requires two reset lines since each row has two different color pixels.
[0060] FIG. 8 illustrates timing waveforms for the pixel array of FIG. 7 . For each row, the exposure time begins when the reset turns low (inactive) for that row and lasts until the pixel is read out. According to this embodiment, readout of all color components is done sequentially by rows. The reset for each color component, however, has different time periods. Differing periods allow the exposure time for the Blue pixels of row n+1 or for row n+3 to be longer than the exposure time for Green pixels in rows n, n+1, n+2, n+3, but shorter than the exposure time for the Red pixels in rows n, n+2. In other words, each color component exposure time may be adjusted to optimize the quality of the captured image.
[0061] The split reset lines for each color employ additional logic in the row decoder of the imaging array. Rather than generating a single reset pulse for each row, a row decoder according to the present embodiment generates a separate reset pulse for each color of the row.
[0062] FIG. 9 depicts a 4-T pixel 900 according to embodiments of the invention. In this embodiment a fourth transistor 901 separates the photo-diode 908 from the reset transistor 902 , the source follower transistor 904 , and the row select transistor 906 . With respect to the reset transistor 902 , a difference between a 4-T and a 3-T pixel is that exposure start is achieved by a combination of a pulse on the gate of the reset transistor 902 concurrently with or a short time before a pulse on the transistor 901 , which charges the photodiode to its initial voltage.
[0063] For a pixel array using a 4-T pixel such as the pixel 900 , the arrangement is similar to that shown in FIG. 7 for a 3-T pixel, except that horizontal TX lines, in addition to the reset lines, are used.
[0064] The timing waveforms for a 4-T pixel array is similar to that shown in FIG. 8 for a 3-T pixel array. For such embodiments, TX lines are wired in parallel to the reset lines and have similar timing waveforms to achieve color-varying exposure.
[0000] 4-T Active Pixel Sensor with Sharing of Pixels Between Two Pixels
[0065] In some embodiments of the present invention, some pixels share various elements. In the embodiment depicted in FIG. 10 , the Reset (RST 1 , RST 2 ), Source-Follower (SF 1 , SF 2 ), and Read (RD 1 , RD 2 ) transistors are shared between two vertically adjacent pixels. FIG. 10 depicts a 2×2 portion of a CIS array.
[0066] FIG. 11 illustrates timing waveforms for use with the circuit of FIG. 110 . The use of such timing waveforms in combination with the circuit of FIG. 10 results in improved SNR since the exposure durations for each color may be determined independently. The timing of the RST and Txx pulses (wherein Txx is T 11 , T 12 , T 21 , and T 22 ) are varied according to feedback from the auto-exposure software.
[0067] The RST line, which is common to all pixels of the two depicted rows of the array, is pulsed four times. The Txx lines of the four color components are pulsed separately, each concurrently with the corresponding RST pulse, thus starting the integration of one of the four pixels of the 4×4 pixel array with each pulse. For readout, the Txx lines are pulsed again, this time simultaneously with read pulses. As is apparent, columns 1 and 2 may be read simultaneously, although row two is read in a subsequent clock cycle from row 1, which is common for Rolling Shutter image capture, widely used with respect to CIS devices. Although not shown, extra reset pulses may be applied prior to readout to achieve correlated double sampling
[0000] 4-T Active Pixel Sensor with Sharing of Transistors Between Four Pixels
[0068] In another embodiment depicted in FIG. 12 , the reset (RST), source-follower (SF) and read (RD) transistors are shared between four adjacent pixels in two neighbor rows and two neighbor columns. A 2×2 portion of the array for this embodiment is depicted. There are separate Transfer lines (Txx) for each of the color components and a single column line (COLUMN) for all four. Hence, each of the four pixel values must be read out during different clock periods. The timing for this embodiment is depicted in FIG. 13 .
[0069] Integration for each pixel is initiated by simultaneous pulses on the RST and respective Txx lines. Read is done sequentially for the four pixels with simultaneous pulses on the READ and respective Txx lines. This achieves different exposure times for each of the color components by having the timing of the RST pulses being determined by Auto-Exposure software or a user input.
[0000] 4-T Active Pixel Sensor with Shared Transistors Between Four Pixels and Shared Transfer Lines Between Two Rows
[0070] The circuit embodiments of FIGS. 10 and 12 use two transfer lines for each row since each row has two color components. The large number of horizontal control lines may undesirably enlarge the area of the pixels. FIG. 14 depicts a 4×2 portion of a 4-T CIS pixel array having transistors shared by four adjacent pixels and having only one transfer line per row (T 1 , T 2 , T 3 , T 4 ). The areas 1402 , 1404 denote the common parts of the respective four-pixel groups and include a source follower transistor, a read transistor, and a reset transistor, which are not shown for simplicity sake.
[0071] As is apparent, each pixel row uses a single horizontal transfer control line (T 1 , T 2 , T 3 , T 4 ), which it shares with a neighbor row. The transfer lines are arranged, however, so that the green pixels for neighboring rows are all controlled by the same transfer line (T 1 , T 3 ). The red and blue pixels on neighboring rows are then controlled by the other transfer line (T 2 , T 4 ). This reduces the number of horizontal controls lines by 50% while still allowing some improvement in SNR with respect to conventional techniques. That is because the embodiments of FIG. 14 facilitates a different exposure time setting for the Green pixels on one hand and for the Red and Blue pixels on the other. FIG. 15 depicts the timing waveform for the embodiment of FIG. 14 . Other groupings (e.g., Green and Blue pixels having one exposure time setting and Red pixels having a different exposure time setting; Green and Red pixels having one exposure time setting and the Blue pixels having a different exposure time setting) may be used.
[0072] As can be see with reference to FIG. 15 , the Red and Blue pixels get the same exposure time, which is longer than that of the Green pixels. This allows the exposure duration to be optimized for the green pixels and either the red or blue pixels for the image. This improves the image quality over conventional systems without requiring an increase in the number of horizontal control lines as with embodiments that allow each color's exposure duration to be determined independently. A corresponding energy profile for this embodiment is depicted in FIG. 16 .
[0073] As can be seen with reference to FIG. 16 , if this were the same captured image whose energy profile is depicted in FIG. 4 , it is apparent that the Red/Blue exposure time has been optimized for the Blue pixels by increasing the Red/Blue exposure time so as to approach saturation. Hence, the SNR for Green and Blue is 22.3 dB and the SNR for Red is 20*log (40*130/60)=18.8 dB.
[0074] Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. For example, although the above embodiments are explained in relation to CMOS imagers, the principals could be extended to CCD or other types of imagers. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention, which is defined in the following claims.
|
A method of capturing an image of a scene using an image capture device having an array of pixels, wherein the array of pixels includes pixels of different colors, includes, for a first duration, capturing a first portion of the scene with a first plurality of the pixels of a first color, and for a second duration, capturing a second portion of the scene with a second plurality of the pixels of a second color. The first and second durations are different and the first and second durations are chosen, at least in part, to improve the signal to noise ratio of the image capture device.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to current transformers for instruments for measuring electric currents and having magnetic cores.
Current transformers for electric current measuring instruments are known per se. Essentially, they consist of a magnetic core with a primary winding carrying the current to be measured and a secondary winding carrying the current which has been matched to the instrument. The ratio of the number of turns in the primary winding to that of the secondary winding determines the transformation ratio u of the current transformer. A large transformation ratio u requires a great number of turns in the secondary winding. For instance, a current transformer with a primary winding consisting of a single turn and carrying 10 A will require a secondary winding of 100 turns to produce a measuring current of 100 mA. A large number of turns usually results in an undesirably large winding capacitance which is detrimental to the precision of the current transformer. Current transformers are sensitive to DC currents. Due to the high initial permeability of the magnetic core material, even a small DC current component will generate an induction current high enough to drive the core into saturation. This gives rise to unacceptable transmission aberrations. In order to reduce sensitivity to DC, current measurement can employ ohmic current dividers in the form of shunts. However, precision measurements using the shunt method are subject to errors due to possible temperature differences between individual current paths as well as to the inductive components of the resistances.
SUMMARY OF THE INVENTION
It is therefore one of the principal objects of the present invention to substantially eliminate the aforementioned disadvantages of known devices and to create a current transformer which requires a reduced number of total winding turns and which measures the AC current component with a negligibly small measurement error despite a superimposed DC current component.
This object is achieved in a current transformer for instruments for measuring electric currents which includes a magnetic core that comprises two cores and a current divider with three parallel current paths; the current dividers form together with the cores two current transformer stages whose magnetic fluxes mutually cancel one another. In a current transformer for AC currents having a DC component, the ratio of the ohmic resistances of the current paths is in direct relation to their transformation ratio. The cores may consist of laminated, annular or ferrite cores.
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 thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the 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 a current transformer in accordance with a preferred embodiment of the invention;
FIG. 2 is a circuit diagram of the transformer of FIG. 1; and
FIG. 3 is a circuit diagram similar to FIG. 2, but embodying a modification.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 schematically shows the arrangement of the current transformer according to the invention which in substance consists of a magnetic core comprising two annular cores K 1 , K 2 and of three inductive current dividers connected in parallel and forming current paths A, B and C. Laminated cores or ferrite cores may be substituted for core rings K 1 , K 2 .
The first current path or circuit A passes through both annular cores K 1 , K 2 and forms two windings N a1 , N a2 consisting of a single turn. The second current path or circuit B comprises two windings N b1 , N b2 having nine turns each, the first winding N b1 being wound on the first annular core K 1 in reverse sense to the first winding N a1 of the first current path A and the second winding N b2 being wound on the second annular core K 2 in the same sense as the second winding N a2 of the first current path A. The third current path C comprises two windings N c1 , N c2 having four turns each which are wound commonly on both annular cores K 1 , K 2 and wherein, whereby the second winding N c2 has an additional turn wound on the second annular core K 2 . It is also possible to wind the first winding N c1 on the first core K 1 and the second winding N c2 on the second core K 2 . The windings N c1 , N c2 of the current path C are wound in reverse sense to the windings N a1 , N a2 of the first current path A. A tapping point M for a measuring instrument is provided in the circuit of the current path B.
The current i to be measured is divided according to FIG. 2 into three partial currents i a , i b and i c , which flow in the first, second and third current paths A, B and C respectively. The first windings N a1 , N b1 and N c1 of each of these current paths or circuits form, with the first annular core K 1 , a first transformer stage W 1 . The second windings N a2 , N b2 and N c2 of each of the current paths form, with the second annular core K 2 a second transformer stage W 2 . The transformer stages W 1 and W 2 balance their magnetic fluxes out. The magnetic flux of the winding N a1 cancels out that of the windings N b1 and N c1 because of the reversed winding sense. In similar manner, the magnetic fluxes of the windings N a2 and N b2 are cancelled out by that of the winding N c2 .
Consequently:
i.sub.a 19 N.sub.a1 =i.sub.b ·N.sub.b1 +1.sub.c ·N.sub.c1 (1)
and
i.sub.c ·N.sub.c2 =i.sub.a ·N.sub.a2 +i.sub.b ·N.sub.b2 (2)
and by employing the corresponding number of winding turns:
i.sub.c =18 i.sub.b (3)
i.sub.a =81 i.sub.b (4).
The transformation ratio is given by the known formula:
u b=i/i.sub.b =(i.sub.a +i.sub.b +i.sub.c)/i.sub.b (5)
Entering the results obtained in (3) and (4) above into equation (5) yields a value of 100 for the transformation ratio. It is therefore possible, with this current transformer, to obtain, with only 29 winding turns in all, the same transformation ratio of 100 as would be obtained in heretofore known devices with 100 secondary winding turns and one primary turn. This signficant economy of turns and consequently of magnet wire results in a reduction of winding capacitance and of manufacturing costs. The division of the current is effected solely by the turn number which determine the desired transformation.
The magnetic fluxes of both current transformer stages W 1 and W 2 due to DC current components must cancel each other out in a similar manner to that in which those due to the basic AC component do. This mutual cancellation is only attained if the ratio of the resistances of the individual current paths A, B anc C is in direct relation to the transformation ratios of said current paths A, B and C. Therefore:
R.sub.a :R.sub.b :R.sub.c =u.sub.c :u.sub.b (6).
In the presence of AC and of DC both transformer stages W 1 , W 2 operate nearly in equilibrium. The compensating current i b is therefore small if the turn numbers of the windings N b1 , N b2 are low, so that the compensating current i b may even be galvanically isolated. A corresponding circuit diagram for both transformer stages W 1 , W 2 is shown in FIG. 3 with the current path B isolated from the current paths A and C. Such a current transformer has the advantage that it is not necessary to use an interstage transformer for galvanic isolation in the current path B, which would in most cases be necessary. The total current i now consists of partial currents i a and i c , so that the transformation ratio is:
u.sub.b =(i.sub.a +i.sub.c)/i.sub.b (7).
Entering the values obtained in (3) and (4) yields a value for the transformation ratio of only 99. In order to obtain a transformation ratio of 100 in this embodiment the turn numbers of windings N b1 and N b2 of the isolated current path B must be made 10 and 8 respectively, which can readily be calculated from formulas (1) and (2).
AC current division is determined by the turn numbers of the individual windings and is therefore subject to the influences of neither temperature nor of the winding resistances. The current division in the presence of DC current components is substantially determined by the ohmic resistances of the current paths A, B and C. The proposed connection in parallel of all three current paths, or of both current paths A and C, permits the employment of low turn numbers even with a large current subdivision, and results in correspondingly low winding capacitances.
By changing the turn numbers of the individual windings, the transformation ratio and thereby the division of the current to be measured can be varied within broad limits. The design of both transformer stages W 1 and W 2 must, however, be such that the current paths are nearly in equilibrium and the magnetic fluxes cancel each other out.
I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.
|
The current transformer for instruments for measuring electric currents includes a magnetic core that has two cores and an inductive current divider with three parallel current paths. The current dividers form, together with cores, two current transformer stages whose magnetic fluxes mutually cancel one another. In a current transformer for AC currents having a DC component, the ratio of the ohmic resistances of the individual current paths is in direct relation to their transformation ratio.
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 085,912, filed Aug. 14, 1987, abandoned, which was a continuation-in-part of U.S. Ser. No. 789,158, filed Oct. 24, 1985, abandoned, which was a continuation-in-part of U.S. Ser. No. 683,975 filed Dec. 20, 1984, abandoned.
FIELD OF THE INVENTION
This invention encompasses novel 2-azetidinone sulfonic acid compounds which have useful antimicrobial activity.
INFORMATION DISCLOSURE
The following documents may be material to the examination of this application.
EP 0 053 816 discloses azetidinone sulfonic acids substituted on the β-lactam ring at position C 4 . Although this document claims any organic residue as a C 4 substituent, this document does not teach the specific C 4 substituents claimed in this case.
EP 053 815, EP 076 758, EP 096 297, EP 093 376 all disclose azetidinone sulfonic acids substituted on the β-lactam ring. The substituents on the β-lactam ring at position C 4 taught by these documents are different than the C 4 substituents claimed in this case.
U.S. Pat. No. 4,478,749 and EP 061 765 disclose azetidinones substituted on the β-lactam ring. These documents teach phosphine derivatives on the lactam ring nitrogen atom and do not teach the sulfonic acid derivatives claimed in this invention.
EP 111 326 discloses a process to prepare chiral azetidinone sulfonic acids. This document teaches only one substituent on the C 4 carbon atom. This substituent is not claimed in this case.
EP 091 236 discloses silylated azetidinones as intermediates to β-lactams. The silylated intermediates taught by this document are not claimed in this case.
EP 27 48 258 discloses azetidinones substituted on the β-lactam ring. The document does not teach the azetidinone sulfonic acid derivatives claimed in this case.
EP 053 387 discloses azetidinones derivatives. This document does not teach any substitution on the lactam ring at C 4 .
SUMMARY OF THE INVENTION
The present invention teaches novel 2-azetidinone sulfonic acid derivatives containing amino acid substituents which are useful as microbial growth inhibitors. This invention includes enantiomers, diastereomeric and racemic mixtures of these compounds. Intermediates and processes for preparing these compounds are also disclosed.
Novel 2-azetidinone compounds within the scope of this invention are represented by Formula I and pharmaceutically acceptable salts thereof wherein R 1 is hydrogen, --OCH 3 , or --NH--CHO, wherein R 2 is an acyl group derived from a carboxylic acid; wherein R 3 is selected from the group consisting of --CH 2 --, --CH 2 CH 2 --, --CH 2 CH 2 CH 2 --, and --CH 2 CH 2 CH 2 CH 2 -- wherein X is NL 2 L 3 then --CH 2 CH 2 --, --CH 2 CH 2 CH 2 -- and --CH 2 CH 2 CH 2 CH 2 -- are optionally substituted with 1 substituent selected from the group consisting of (C 1 -C 4 )alkyl, (C 1 -C 4 )alkoxy, (C 1 -C 4 )alkylthis, and (C 1 -C 4 )carboxyalkyl; wherein X is --NL 2 L 3 or a pyrrole of Formula II; wherein L 1 is hydrogen, (C 1 -C 4 )alkyl, --(C 6 H.sub. 5), --COH, --CO--O--CH 2 --(C 6 H 5 ) or SO 3 M; wherein L 2 and L 3 are the same or different and are hydrogen. (C 1 -C 4 )alkyl, --CO--(C 1 -C 4 )alkyl, (C 1 -C 4 )carboxyalkyl, ═CH=NH, --C(NH 2 )=NH,--(C 6 H 5 ), --CO--O--CH 2 --(C 6 H 5 ),--COH, or --SO 3 M with the proviso that if one of L 2 or L 3 is --SO 3 M, the other is hydrogen and wherein M is hydrogen, sodium, potassium or a quaternary ammonium salt.
Novel compounds within the scope of this invention which are useful as intermediates to 2-azetidinone sulfonic acid derivatives having microbial growth inhibition include compounds of Formula I wherein L 1 or L 2 are --CO--O--CH 2 --(C 6 H 5 ).
A detailed description of the acyl groups included in R 2 is found in U.S. Pat. No. 4,478,749, column 8, line 41 to column 12, line 50, as those terms are defined at column 7, line 34 through column 8. line 22, all of which is incorporated by reference herein.
Preferred acyl groups of R 2 include those which have been used to acylate 6-aminopenicillanic acid, 7-aminocephalosporic acid and their derivatives which can be found in "Chemistry and Biology of β-Lactam Antibiotics, Vol. 1, R. B. Morin and M. Gorham, ed., Academic Press, N.Y.1982 and include the following fragments: 2-Cyanoacetyl, Aminophenylacetyl, Amino(4-hydroxyphenyl)acetyl, α(Thien-2-yl)acetyl, α(Thien-3-yl)acetyl, Phenylacetyl, Hydroxyphenylacetyl, (Formyloxy)-phenylacetyl, [(Trifluoromethyl)thio]acetyl, 2-(3,5-Dichloro-4-oxo-1-(4H)-pyridyl)acetyl, (1H-Tetrazol-1-yl)acetyl, (2-Amino-4-thiazolyl)-2-methoxyiminoacetyl, 2-[(Cyanomethyl)thio]acetyl, [[(4-Ethyl-2,3-dioxo-1-piperizinyl)carbonyl]amino]phenylacetyl, [[(4-Ethyl-2,3-di-oxo-piperazinyl)carbonyl]amino](4-hydroxyphenyl)acetyl, 2-(Aminomethyl)phenylacetyl, 4-(Carbamoylcarboxymethylene)-1,3-dithiethane-2-carbonyl, 3-(o-Chlorophenyl)-5-methyl-4-isoxazolecarbonyl, 2-p-[(1-4,5,6-Tetrahydro-2-pyrimidinyl)phenyl]acetyl, Amino-1,4-cyclohexadien-1-yl-acetyl, Phenylsulfoacetyl, (2R)-2-amino-2-(m-methanesulfonamidophenyl)acetyl, (2-Amino-4-thiazolyl)-2-(1-carboxy-1-methylethoxy)iminoacetyl, 2-(1H-Tetrazol-1-yl)acetyl, (2,3-Dihydro-2-imino-4-thiazolyl)(methoxyimino)acetyl, (2-Amino-4-thiazol)carboxymethoxyiminoacetyl, (2-Aminopyridin-6-yl)methoxyiminoacetyl, (2-Aminopyridin-6-yl)carboxymethoxyiminoacetyl, (4-Amino-2-pyrimidyl)methoxyiminoacetyl, (5-Amino-1,2,4-thiadiazol-3-yl)-2-methoxyiminoacetyl, (5-Amino 1,2,4-thiadiazol 3-yl)-2-carboxymethoxyiminoacetyl, (5-Amino-1,2,4-thiadiazol-3-yl) 1-carboxy-1-methylethoxy)iminoacetyl, D-α[[(Imidazolidin-2-on-1-yl)-carbonyl]amino]phenylacetyl, D-α[[(3-mesyl-imidazolidin-2-on-1-yl)carbonyl]amino]phenylacetyl, 2,6-Dimethylbenzoyl, (S)-2-(4-hydroxy-1,5-naphthyridine-3-carboxamido-2-phenylacetyl.
Preferred compounds within the scope of this invention include compounds wherein the organic acid derivative, R 2 , is an oximinoacyl moiety represented by Formula III wherein R 4 is --CH 3 , --CH 2 --CO 2 --R 5 , or --C(CH 3 ) 2 --CO 2 --R 5 ; wherein R 5 is hydrogen, (C 1 -C 4 ) alkyl, --CH(C 6 H 5 ) 2 , --CH 2 (C 6 H 5 ), or a cation; and wherein R 6 is hydrogen, --CO--O--C(CH 3 ) 3 , --CO--O--CH 2 --(C 6 H 5 ), or --C(C 6 H 5 ) 3 .
Novel compounds within the scope of this invention wherein R 2 is an oximinoacyl moiety represented by Formula III which are useful as intermediates to 2-azetidinone sulfonic acid derivatives having microbial growth inhibition include compounds wherein R 5 is (C 1 -C 4 ) alkyl, --CH(C 6 H 5 ) 2 , or --CH 2 (C 6 H 5 ); and wherein R 6 is --CO--O--C(CH 3 ) 3 , --CO--O--CH 2 --(C 6 H 5 ), or --C(C 6 H 5 ) 3 .
DETAILED DESCRIPTION
The compounds of this invention are identified in two ways: by a descriptive chemical name and by numerical identification which corresponds to the appropriate structure contained in the structure charts. In appropriate situations, the proper stereochemistry is represented in the structure charts as well.
The various carbon moieties are defined as follows: Alkyl refers to an aliphatic hydrocarbon radical and includes branched or unbranched forms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl.
Alkoxy refers to an alkyl radical which is attached to the remainder of the molecule by oxygen and includes branched or unbranched forms such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, and t-butoxy.
Alkylthio refers to an alkyl radical which is attached to the remainder of the molecule by sulfur and includes branched or unbranched forms such as methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, and t-butylthio.
Carboxyalkyl refers to an alkoxy radical which is attached to the remainder of the molecule by a carbonyl group and includes branched or unbranched forms such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, and t-butoxycarbonyl.
Unless otherwise indicated, in the above description and throughout this document the parenthetical term (C n -C m ) is inclusive such that a compound of (C 1 -C 4 ) would include compounds of 1, 2, 3 and 4 carbons and their isomeric forms.
It will be apparent to those skilled in the art that compounds of this invention may exist in different tautomeric forms. The scope of this invention includes all tautomeric forms in addition to those represented in the formulas used herein.
It will be apparent to those skilled in the art that compounds of this invention may contain several chiral centers. The scope of this invention includes all enantiomeric or diastereomeric forms of Formula I compounds either in pure form or as mixtures of enantiomers or diastereomers. Specifically, the azetidinones of this invention have chiral carbon atoms at positions C 3 and C 4 of the β-lactam ring. The preferred form is cis at centers 3 and 4 and the preferred stereochemistry at C 3 and C 4 is 3(S) and 4(S). The phrase "cis at centers 3 and 4" means that the substituents at C-3 and C-4 are both oriented on the same side of the β-lactam ring.
The scope of this invention includes the pharmaceutically acceptable acid salts of the disclosed compounds. Acid salts are formed by reacting the compounds described herein with the appropriate acid in a suitable solvent. Suitable acids for this purpose include hydrochloric, sulfuric, phosphoric, hydrobromic, hydroiodic, acetic, lactic, citric, succinic, benzoic, salicylic, palmoic, cyclohexansulfamic, methanesulfonic, naphthalenesulfonic, p-toluenesulfonic, maleic, fumaric, or oxalic.
The scope of this invention includes the pharmaceutically acceptable salts of the disclosed compounds. Such salts include the following cations but are not limited to these: alkali metal ions such as potassium, sodium, lithium, alkaline earth metal ions such as magnesium or calcium and ammonium ions such as ammonium, tetralkylammonium and pyridinium Metal salts are formed by suspending the compounds in water or other suitable solvent and adding a dilute metal base such as sodium or potassium bicarbonate until the pH is between 6 and 7.
The compounds of this invention and their respective pharmaceutically acceptable salts have antibiotic activity against a variety of gram-negative bacteria including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The compounds are useful for treating bacterial infections in animals, including and most preferably humans. Compounds of the invention are tested for in vitro antimicrobial activity using standard testing procedures such as the determination of minimum inhibitory concentration (MIC) by methods described in "Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically" (M7-A) Published December 1985 by the National Committee for Clinical Laboratory Standards, 771 East Lancaster Avenue, Villanova, PA 19084. Briefly, MIC values are determined in unsupplemented Mueller Hinton Agar (MHA). The compounds tested are diluted serially into molten MHA at 47° C. The agar is poured into petri dishes and allowed to harden. The various bacteria used for testing are grown overnight on MHA at 35° C. and transferred to Tryptiease Soy Broth (TSB) until a turbidity of 0.5 McFarland standard is obtained. The bacteria are diluted one to twenty in TSB and inoculated on the plates (1 μl using a Steers replicator). The plates are incubated at 35° C. for 20 hours and the MIC is read to be the lowest concentration of drug that completely inhibits visible growth of the bacterium. The MIC test results of two typical compounds of this invention are given in Table I.
Various compositions of the present invention are presented for administration to humans and animals in unit dosage forms, such as tablets. capsules, pills, powders, granules, sterile parenteral solutions or suspensions, eye drops, solutions or suspensions, and emulsions containing suitable quantities of compounds of Formula I.
For oral administration solid or fluid unit dosage forms can be prepared. For preparing solid compositions, the compounds of this invention are mixed with conventional ingredients such as talc, magnesium stearate, dicalcium phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose, acacia, methylcellulose, and/or functionally similar pharmaceutical diluents or carriers. Capsules are prepared by mixing the compound with an inert pharmaceutical diluent and filling the mixture into a hard gelatin capsule of appropriate size. Soft gelatin capsules are prepared by machine encapsulation of a slurry of the compound with an acceptable vegetable oil, light liquid petrolatum or other inert oil.
For preparing fluid compositions, the compounds of this invention are dissolved in an aqueous vehicle together with sugar, aromatic flavoring agents and preservatives to form a syrup. An elixir is prepared by using a hydroalcoholic vehicle such as ethanol, suitable sweeteners such as sugar and saccharin, and aromatic flavoring agents. Suspensions are prepared in an aqueous vehicle with the aid of a suspending agent such as acacia, tragacanth, or methylcellulose.
For parenteral administration, fluid unit dosage forms are prepared utilizing the compound and a sterile vehicle, water being preferred. The compound, depending on the vehicle and concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions the compound can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampoule and sealing. Advantageously. adjuvants such as a local anesthetic, preservative and buffering agents can be dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. The dry lyophilized powder is then sealed in the vial and an accompanying vial of water for injection is supplied to reconstitute the liquid prior to use. Parenteral suspensions can be prepared in substantially the same manner except that the compound is suspended in the vehicle instead of being dissolved and sterilization cannot be accomplished by filtration. The compound can be sterilized by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound.
The compounds of Formula I may also be administered in a carrier suitable for topical administration, such carriers include creams. ointments, lotions, pastes, jellies, sprays, aerosols, bath oils, or other pharmaceutical carriers which accomplish direct contact between the compound and the surface of the skin area to be treated. In general pharmaceutical preparations may comprise from about 0.01% to about 10%, and preferably from about 0.1% to about 5% by w/w of the active compound in the suitable carrier.
Additionally, a rectal suppository can be employed to deliver the active compound This dosage form is of particular interest where the mammal cannot be treated conveniently by means of other dosage forms, such as orally or by insufflation, as in the case of young children or debilitated persons. The active compound can be incorporated into any of the known suppository bases by methods known in the art. Examples of such bases include cocoa butter, polyethylene glycols (carbowaxes), polyethylene sorbitan monostearate, and mixtures of these with other compatible materials to modify the melting point or dissolution rate. These rectal suppositories can weigh from about 1 to 2.5 g.
The term "unit dosage form", as used in the specification. refers to physically discrete units suitable as unitary dosages for human subjects and animals, each unit containing a predetermined quantity of active material calculated to produce the desired pharmaceutical effect in association with the required pharmaceutical diluent, carrier or vehicle. The specifications for the novel unit dosage forms of this invention are dictated by and directly dependent on the unique characteristics of the active material and the particular effect to be achieved and the limitations inherent in the art of compounding such an active material for use in humans and animals, as disclosed in detail in this specification, these being features of the present invention. Examples of suitable unit dosage forms in accord with this invention are tablets, capsules, pills, suppositories, powder packets, wafers, granules, cachets, teaspoonfuls, tablespoonfuls, drops, ampules, vials, aerosols with metered discharges, segregated multiples of any of the foregoing, and other forms as herein described.
An effective quantity of the compound is employed in treatment. The dosage of the compound for treatment depends on many factors that are well known to those skilled in the art. They include for example, the route of administration and the potency of the particular compound. A dosage schedule for humans having an average weight of 70 kg is from about 50 to about 3000 mg of compound in a single dose. More specifically, the single dose is from about 100 mg to 2000 mg of compound. Typically the dosages are given one to four times per day.
The process for making compounds of Formula I is illustrated in Charts A and B. The requirements for protecting groups in the processes of Charts A and B are well recognized by one skilled in the art of organic chemical synthesis and suitable protecting groups are used in the processes of Charts A and B. It is recognized that conditions for introduction and removal of protecting groups should not detrimentally alter any other groups in the molecule.
Examples of suitable nitrogen protecting groups are:
(1) benzyl;
(2) triphenylmethyl (trityl);
(3) trialkylsilyl, such as trimethylsilyl or t-butyldimethyl silyl;
(4) t-butoxycarbonyl (t-BOC or BOC);
(5) benzyloxycarbonyl (Cbz);
(6) trifluoroalkanoyl, such as trifluoroacetyl or trifluoropropionyl; or
(7) diphenyl(methyl)silyl.
Introduction and removal of such nitrogen protecting groups are well known in the art of organic chemistry: See, for example, (1) J. F. W. McOmie, Advances in Organic Chemistry, Vol. 3, pages 191-281 (1963); (2) R. A. Boissonas, Advances in Organic Chemistry, Vol. 3, pages 159-190 (1963); (3) "Protective Groups in Organic Chemistry", J. F. W. McOmie, Ed., Plenum Press, New York. 1973, pg 74, and (4) "Protective Groups in Organic Synthesis", Theodora W. Greene, John Wiley and Sons. New York, 1981.
Under certain circumstances it may be necessary to protect two or more nitrogen atoms with different protecting groups allowing selective removal of one protecting group while leaving the remaining protecting groups in place. For example, the Cbz group can be selectively removed in the presence of the BOC group and vice versa.
The process for making compounds of Formula I is illustrated in Chart A. The starting compound, A-1. can be made by methods known in the art; J. Am. Chem. Soc., 2401-2404 (1973) or by the process illustrated in Chart B. Compound A-1 may be substituted on the lactam ring at the C 3 position with R 1 where R 1 is hydrogen, methoxy or --CO--NH 2 . Methods for introducing methoxy and --CO--NH 2 substituents at C 3 of the lactam ring are known in the art; J. Am. Chem. Soc., 2401-2404 (1973).
Compound A-1 reacts with commercially available or known compounds of the formula HO 2 C--R 3 --X, where R 3 and X are defined above, to prepare compound A-2. The general conditions for conducting this acylation are well known in the art. A preferred method involves reacting compound A-1 with the appropriate carboxylic acid in the presence of dicyclohexylcarbodiimide and 1-hydroxybenzotriazole and a catalytic amount of 4-dimethylaminopyridine. The reaction can be conducted at a temperature of about 0°-30° C. for a time of about 1 to 5 hours. Compound A-2 can be isolated from the reaction mixture by methods known in the art such as crystallization or chromatography.
Compound A-2 reacts with a sulfonating agent to give compounds of Formula I. If necessary, protecting groups well known in the art are placed on sites subject to random sulfonation. A preferred manner of introducing the sulfono group is by reacting dimethylformamide sulfur trioxide with an optionally protected compound A-2 in a suitable solvent. The reaction can be conducted at a temperature of about -20° to 60° C. for a time of about 1 to 5 hours. Preferred reaction temperature and reaction times are about 0° to 25° C. and 1 to 3 hours, respectively. Solvents that can be used include dimethylformamide and methylene chloride. The preferred solvent is dimethylformamide. The sulfonated compound is removed from the reaction mixture by methods known in the art and any protecting groups are removed by known methods to give compounds of Formula I.
Chart B outlines an alternative preparation of compound A-1. The known lactam, B-1; J. Org. Chem., 47:2765-2767 (1982), is silylated on N 1 with silylating agents well known in the art. Typically, a trialkylsilyl chloride or an arylalkylsilyl chloride in the presence of an organic base is used. The reaction is conducted at a temperature of about 0° to 25° C. for a period of about 1 to 5 hours in any of several anhydrous solvents. e.g., ethyl acetate, dioxane, tetrahydrofuran, or dimethylformamide, in the presence of either an inorganic base, or a tertiary amine such as trialkylamine or imidazole. A preferred solvent is dimethylformamide.
The silylated azetidinone is then reduced to give the compound B-2. The reduction is conducted in the presence of a metal hydride at a temperature range of 0° C. to room temperature for times of 2 to 5 hours. The preferred method uses lithium borohydride in anhydrous tetrahydrofuran under cold conditions for several hours. The reduced compounds can be purified by methods known in the art.
The protecting group on the C 3 positon is removed by hydrogenolysis in the presence of palladium black under hydrogen gas and converted to the amide. B-3, following a variety amide or peptide forming reactions such as those described in Methoden der Organischem Chemie, Vierte Auflage, Band XV/2, E Wunch ed., Georg Thieme Verlag, Stuttgart, p. 1. A preferred acylation process is the use of approximately molar quantities of a desired acid, 1-hydroxy-benzotriazole, and a carbodiimide, such as dicyclohexylcarbodiimide. The reagents are added to the solution of the amine in a solvent, such as tetrahydrofuran- dimethylformamide, or acetonitrile. A temperature of 0°-60° C. is operative, with 20°-35° C. preferred. The time of reaction is variable from 0.5-24 hr being required. although usually 3.4 hr is sufficient A precipitate of dicyclohexylurea is formed during the reaction. This is removed by filtration. The amides are isolated from the filtrate by extractive procedures and chromatography.
After the amidation, the protecting silyl group is removed to give compound A-1. Desilylation is accomplished by reacting compound B-3 with a fluoride ion in the presence of a solvent at a temperature of about -20° to 60° C. for a time of about 1 to 12 hours. Preferred are about 0° to 25° C. and 1 to 5 hours, reaction temperature and times respectively. Solvents that can be used include methylene chloride, methanol, tetrahydrofuran and ethanol. The preferred method of conducting this step is to treat the compound with triethylammonium fluoride in methanol.
Optically active isomers of the disclosed compounds are resolved by methods known in the art; Takeda European patent application 8310461-3. The resolving agents are any of the commercially available and commonly used resolving agents such as optically active camphorsulfonic acid, bis o-toluoyltartaric acid, tartaric acid, and diacetyl tartaric acid. Illustrative examples are given in Organic Synthesis, Coll. Vol. V., p. 932 (1978).
Compounds of this invention are converted into optically active diastereomeric salts by reaction with an optically active acid in a manner standard in the isomer resolution art. The optically active acids include the resolving agents described above. These diastereomeric salts can then be separated by methods known in the art. Preferably the separation of enantiomers is carried out by forming salts of optically active tartaric acid or derivatives thereof and taking advantage of the difference in solubility between the resulting diastereomers Salt formation is carried out prior to acylation of the amino acid moiety at the C 4 position of the azetidinone ring. The preferred starting compound for making optically active compounds of Formula I, cis-(±)-1[(2', 4'-dimethoxyphenyl)methyl]-4-(methoxycarbonyl)-3-phenylmethoxycarboxyamido-2-azetidinone, is known; Chem. Pharm. Bull., 32:2646-2659 (1984). The C 3 protecting group is removed by hydrogenolysis to the corresponding free amine. An appropriate substituted tartaric acid enantiomer is then added such as (+)-di-p-toluoyl-D-tartaric acid and reaction conditions altered to facilitate precipitation of the appropriate azetidinone diastereomeric salt. The tartaric acid is removed by treating the compound with inorganic base such as sodium bicarbonate to obtain enatiomerically pure amino-azetidinone which is made into compounds of Formula I by the methods described above.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, practice the present invention. The following detailed examples describe how to prepare the various compounds and are to be construed as merely illustrative, and not limitations of the preceding disclosure. Those skilled in the art will recognize appropriate variations in reactants and reaction conditions and techniques which are equivalent to the described procedures.
EXAMPLE 1
Cis-(±)-1-t-butyldimethylsilyl-3-[[2'-(phenylmethoxy) carbonyl]-amino]4-methoxycarbonyl-2-azetidinone.
The reagent, t-butyldimethylsilylchloride (33.4 g), is added with stirring to a solution of cis-(±)-4-(methoxycarbonyl)-2 -oxo-3[[(phenylmethoxy)carbonyl]amino]-1-azetidine (56.1 g), triethylamine (26.5 g) and 4-dimethylaminopyridine (3.3 g) in anhydrous dimethylformamide (300 ml) at 0° C. After 30 minutes the reaction temperature is warmed to room temperature and stirred for 3 hours. The precipitated solid is filtered and the filtrate is concentrated under reduced pressure. The residue is dissolved in ethyl acetate, washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the title compound (71.9 g).
Melting point: 115°-117° C.
EXAMPLE 2
Cis-(±)-1-t-butyldimethylsilyl-4-hydroxymethyl-3-[[2-(phenylmethoxy)carbonyl]amino]-2-azetidinone.
Lithium borohydride (1.47 g) is added to a stirred solution of cis-(±)-1-t-butyldimethylsilyl-3-[[2'-(phenylmethoxy)carbonyl]amino]-4-methoxycarbonyl-2-azetidinone (6.907 g) in anhydrous tetrahydrofuran (50 ml) at 0° C. The reaction mixture is kept at 0° C. for 4 hours and then is quenched by slowly adding acetic acid (16 ml) solution in ethyl acetate (50 ml) and aqueous sodium bicarbonate solution. The organic layer is washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give a viscous material. This crude product is passed through a silica gel column eluting with hexane/ethyl acetate (2:1), which affords the title product (5.15 g).
1 H-NMR(δ, CDCl 3 ) 7.4, 6.05, 5.25, 3.85, 2.45, 0.9, 0.35, 0.25.
EXAMPLE 3
Cis-(±)-1-t-butyldimethylsilyl-4-hydroxymethyl-3-amino-2-azetidinone.
Palladium-black (2.5 g) in ethanol (20 ml) is added to a solution of cis-(±)-1t-butyldimethylsilyl-4-hydroxymethyl-3-[[2'-(phenylmethoxy)carbonyl]amino]-2-azetidinone (5.0 g) in methanol (50 ml) under one atmosphere of hydrogen gas at room temperature. The reaction is complete in 40 minutes Toluene (10 ml) is added to the mixture and stirred for 5 minutes. The catalyst is filtered and washed with methanol. The filtrate is concentrated under reduced pressure to give the title compound (3.16 g).
EXAMPLE 4
Cis-(±)-1(t-butyldimethylsilyl)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-hydroxymethyl-2-azetidinone.
Dicyclohexylcarbodiimide (347 mg) is added to a mixture of cis-(±)-1-t-butyldimethylsilyl-4-hydroxymethyl-3-amino-2-azetidinone (320 mg), 2-(2'-triphenylmethylamino)-2-(methoxyimino) acetic acid (860 mg, 87% purity by weight), 1-hydroxybenzotriazole (227 mg) in methylene chloride (10 ml) at 0° C. After one hour the ice bath is removed and the reaction mixture is kept at ambient temperature overnight. The solid is filtered and washed with methylene chloride (30 ml). Aqueous sodium bicarbonate solution (10 ml) is added to the filtrate, stirred for 20 minutes, dried over anhydrous sodium sulfate and concentrated under reduced pressure. Preparative thin layer chromatography on silica gel developing with 3:1/hexane:ethyl acetate gives the title compound (700 mg). 1 H-NMR (δ, CDCl 3 ) 7.25, 6.45, 5.4, 3.95, 4.35˜3.7, 0.9, 0.35, 0.25.
EXAMPLE 5
Cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)--(Z)-2'-(methoxyimino)acetamido]-4-hydroxymethyl-2-azetidinone.
A 1M solution of aqueous triethylammonium fluoride in methylene chloride (1.5 ml) is added to a solution of cis-(±)-1-(t-butyldimethylsilyl)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)--(Z)-2'-(methoxyimino)acetamido}-4-hydroxymethyl-2-azetidinone (656 mg) in methanol (10 ml) at room temperature. After one hour solid sodium bicarbonate (100 mg) is added to the reaction mixture and the reaction is concentrated under reduced pressure. Ethyl acetate (100 ml) and water (50 ml) are added to the residue, the organic layer is dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the title product (509 mg).
1 H-NMR(δ, CDCl 3 ) 7.25, 6.65, 6.4, 5.4, 3.95, 4˜3.5, 8.73, 8.3, 7.32, 6.8, 5.76. 5.15, 4.75. 3.8, 3.75˜3.25.
EXAMPLE 6
Cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-L-pyroglutamoyloxymethyl-2-azetidinone.
Dicyclohexylcarbodiimide (445 mg) is added to a heterogeneous mixture of cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl) -(Z)-2'-(methoxyimino)acetamido]-4-hydroxymethyl-2-azetidinone (1.0 g), L-pyroglutamic acid (256 mg), 1-hydroxybenzotriazole (243 mg) and a small amount of 4A molecular sieves in anhydrous tetrahydrofuran (20 ml) at room temperature. After 16 hours, the solid is filtered, washed with methylene chloride (100 ml) and the filtrate is stirred for 30 minutes in the presence of aqueous sodium bicarbonate solution. The organic layer is dried over anhydrous sodium sulfate, concentrated under reduced pressure and is passed through a medium pressure silica gel column eluting with 6:1/ethyl acetate:methanol to give the title compound (876 mg).
1 H-NMR(δ, CD 3 OD) 7.3, 6.8, 5.25. 5.0˜4.5, 3.9, 2.4˜2.1.
EXAMPLE 7
Cis-(±)-3[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-[L-pyroglutamoyl-oxymethyl]-2-oxo-1-azetidinesulfonic acid monopotassium salt (Compound 7) and cis-(±)-[2-(2'-amino-4'-thiazolyl) -(Z)-2-(methoxyimino)-acetamido]-4-[L-pyroglutamoyl-N-sulfonic acid-oxymethyl]-2-oxo-1-azetidinesulfonic acid dipotassium salt (Compound 2). -
A 0.9M solution of sulfur trioxide in dimethylformamide (9 ml) is added to a solution of cis-(±)-3-[2'-(2"-triphenylmethylamino-4'-thiazolyl)-(Z)-2(methoxyimino)acetamido]-4-[L-pyroglutamoyloxymethyl]-2-azetidinone (740 mg) in methylene chloride (5 ml) at room temperature and the reaction mixture is kept at ambient temperature for 45 minutes. Additional dimethylformamide-sulfur trioxide solution (0.5 ml) is added and after 20 minutes aqueous monobasic potassium phosphate (408 mg) in water (10 ml) is added followed by methylene chloride (30 ml) The organic layer is taken, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residual material is dissolved in 70% formic acid (6 ml) and kept at room temperature for 3 hours. The solid is filtered, washed with 70% formic acid (10 ml) and the filtrate is concentrated under reduced pressure to give 620 mg of material.
The sulfonic acid compound is dissolved in water (40 ml) and an aqueous potassium bicarbonate solution is added adjusting pH to 6.5. The small amount of insoluble material is filtered and the filtrate is lyophilized to give 500 mg of material. This crude product is passed through a column of HP-20 resin eluting with water to give the dipotassium salt (59 mg) and the monopotassium salt (18 mg). An additional 100 mg of the monosulfonate compound is giveed by eluting the column with 20% acetone in water. Monopotassium salt: 1 H NMR (δ, D 2 O) 7.02, 5.04 and 5.01, 4.98˜4.4, 4.0 and 3.96, 2.65˜2.0. Dipotassium salt: 1 H NMR (δ, D 2 O) 7.02 and 7.0, 5.62 and 5.54, 4.85-4.35, 4.0 and 3.96, 2.85˜2.0.
EXAMPLE 8
Cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)- 2'-(methoxyimino)acetamido]-4-L-N-phenylmethoxycarbonylpyroglutamoly-oxmethyl-2-azetidinone.
A mixture of cis-(±)-3-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-hydroxymethyl-2-azetidinone (454 mg), L-phenylmethoxycarbonylpyroglutamic acid (230 mg), 1-hydroxybenzotriazole (113 mg), dicyclohexylcarbodiimide (207 mg) and dimethyl aminopyridine (30 mg) in anhydrous tetrahydrofuran (20 ml) is stirred at room temperature for one day. Additional phenylmethoxycarbonylpyroglutamic acid (40 mg) is added and allowed to stand for 10 hours. The solid is filtered, washed with ethyl acetate (200 ml) and the filtrate is stirred in the presence of aqueous sodium bicarbonate solution. The organic layer is taken, dried over sodium sulfate and concentrated under reduced pressure. Preparative thin layer chromatography on silica gel of this crude product developing with ethylacetate/hexane/methanol (4:4:1) affords the title compound (580 mg).
1 H-NMR(δ, CDCl 3 ) 7.36˜0.29, 6.7, 5.9, 5.25, 4.75˜4.1, 4.0, 2.7˜1.9.
EXAMPLE 9
Cis-(±)-3[2'-(2"-amino-4"-thiazolyl) -(Z)-2'-(methoxyimino) acetamido]-4-[-L-N-phenylmethoxycarbonyl pyroglutamoyl-oxymethyl]-2-oxo-1-azetidinesulfonic acid potassium salt (Compound 3).
The title compound is prepared by a procedure similar to the one described in Example 7, sulfonation of cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl) -(Z)-2'-(methoxyimino)acetamido]-4-[L-N-phenylmethoxycarbonylpyroglutamoyl-oxymethyl]-2-azetidinone followed by detritylation, potassium salt formation and purification using Hp-20 resin.
1 H-NMR(δ, D 2 O) 7.5, 7.0 and 6.98, 5.5˜4.3, 3.98 and 3.97, 2.8˜2.0.
EXAMPLE 10
Cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-N-acetylglycinoyl) -oxymethyl-2-azetidinone.
A mixture of cis-(±)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-hydroxymethyl-2-azetidinone (542 mg), 1-hydroxybenzotriazole (1.04 mmole), N-acetylglycine (180 mg), dicyclohexylcarbodiimide (340 mg) and small amount of 4 Å molecular sieve in dimethylformamide (5 ml) is stirred at room temperature for 2 days. The solid material is filtered, washed with ethyl acetate (100 ml) and the filtrate is stirred in the presence of aqueous sodium bicarbonate solution (300 mg of sodium bicarbonate in 25 ml of water) for 20 minutes. The organic layer is taken, dried over sodium sulfate and concentrated under reduced pressure. The residue is passed through a medium pressure silica gel column eluting with hexane/ethyl acetate (1:1) followed by hexane/ethyl acetate (1:2) and then ethyl acetate to give the title compound (360 mg).
1 H-NMR(δ, CDCl 3 ) 7.9, 7.28, 7.0, 6 63, 5.3. 3.94, 3.75, 4.4˜4.0, 1.92.
EXAMPLE 11
Cis-(±)-3-[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(methoxyimino) acetamido]4-[N-acetylglycinoyl-oxymethyl]-2-oxo-1-azetidine sulfonic acid potassium salt (Compound 5).
A 0.95M solution of sulfur trioxide in dimethylformamide (0.5 ml) is added to a solution of cis-(±)-3-[2-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-[N-acetylglycinoyl-oxymethyl]-2-azetidinone (300 mg) in methylene chloride (3 ml) at 0° C. and it is kept at 0° C. for 20 minutes. An additional 0.25 ml of dimethylformamide,sulfur trioxide solution is added and stirred at 0° C. for 20 minutes The reaction is quenched by adding aqueous potassium phosphate monobasic (150 mg in 5 ml water) followed by tetra-N-butylammonium hydrogen sulfate (340 mg). The sulfonated product is extracted with methylene chloride (50 ml), dried over sodium sulfate and concentrated under reduced pressure. The material giveed is dissolved in 70% formic acid (10 ml) and after 4 hours detritylation is complete. The solid is filtered, washed with 70% formic acid (10 ml) and the filtrate is concentrated under reduced pressure. Potassium salt formation is made by passing this tetra-n-butylammonium salt through Dowex-K+resin and purification by HP-20 resin column chromatograph to give the title compound (200 mg). 1 H-NMR(δ, CD 3 OD) 6.84, 5.35, 4.47. 3.96, 3.93, 1.98.
EXAMPLE 12
Cis-(±)-3-[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]4-N-phenylmethoxycarbonyl glycinoyl-oxymethyl-2-oxo-1-azetidinesulfonic acid Potassium salt (Compound 4).
The title compound is produced by following the procedures given in Examples 10 and 11 and substituting N-phenylmethoxycarbonyl glycine methyl ester for N-acetylglycine. 1 H-NMR (δ, CD 3 OD) 7.3, 6.85, 5.4, 5.1, 4.8˜4.3, 2.95.
EXAMPLE 13
Cis-(±)-3-[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido]-4-[N-formylglycinoyl-oxymethyl]-2-oxo-1-azetidine sulfonic acid potassium salt (Compound 6)
The title compound is produced by following the procedures given in Examples 10 and 11 and substituting N-formylglycine for N-acetyl glycine.
1 H-NMR(δ, CD 3 OD) 8.1, 6.85, 5.35, 4.45. 4.05, 3.95, 4.6˜4.4.
EXAMPLE 14
Cis-(±)-1-(t-butyldimethylsilyl)-3-[2'-[(2"-t-butoxycarbonylamino)-4"-thiazolyl]-[2'-(1'"-t-butoxycarbonylmethoxy)imino]]-acetamido-4-hydroxymethyl-2-azetidinone.
Dicyclohexylcarbodiimide (3.86 g) is added to a stirred mixture of cis-(±)-1-t-butyldimethylsilyl-4-hydroxymethyl-3-amino-2-azetidinone (3.6 g), 2-(2-t-butoxycarbonylaminothiazol-4yl)-(Z)-2-(butoxycarbonyl)(methoxyimino)acetic acid (6.9 g) and 1-hydroxybenzotriazole (2.11 g) in methylene chloride (40 ml) in an ice bath. The ice bath is removed after 2 hours and the reaction mixture is stirred overnight at room temperature. The precipitated solid is filtered, washed with methylene chloride (60 ml) and the filtrate is stirred with aqueous sodium bicarbonate (1.5 g sodium bicarbonate in 35 ml water) for 20 minutes at room temperature. The organic layer is taken, dried over sodium sulfate and concentrated under reduced pressure. Treatment of the residual material with ether gives the title compound (4.5 g). The mother liquor is concentrated and passed through the medium pressure silica gel column eluting with 3:1/hexane:ethyl acetate to give additional title compound (2.2 g). 1 H-NMR(δ, CDCl 3 ) 8.2, 8.0, δ 7 28, 5.5, 4.66, 4.64, 4.0˜3.7, 1.6, 1.49, 1.54, 0.96, 0.24, 0.22.
EXAMPLE 15
Cis-(±)-3-[2'-[(2"-t-butoxycarbonylamino)-4"-thiazolyl]2'-[(1'"-t-butoxycarbonylmethoxy)imino]-acetamido-4-hydroxymethyl]-2-azetidinone.
Triethylammonium fluoride in methylene chloride (12.7 mmole, prepared by mixing triethylamine and 48% hydrofluoric acid in methylene chloride in an ice bath) is added at room temperature to a stirred solution of cis-(±)-1-(t-butyldimethylsilyl)-3-[2'-[(2"-t-butoxycarbonyl amino)-4"-thiazolyl]-(Z)-[2'-(1'"-t-butoxycarbonylmethoxy)imino]] acetamido-4-hydroxymethyl azetidinone (6.5 g) in methanol (60 ml) and the solution is allowed to stand for 30 minutes. Sodium bicarbonate solid (4.2 g) is added to the reaction mixture, the methanol is evaporated under the reduced pressure and methylene chloride (150 ml) and water are added (30 ml). The organic layer is taken, dried over sodium sulfate, concentrated under reduced pressure, washed with diethyl ether and dried to give the title compound (4.9 g).
Melting point: 195° C. (decomp.).
EXAMPLE 16
Cis-(±)-3-[2'-[(2"-t-butoxycarbonylamino) -4"-thiazolyl]-(Z)-2-[(1'"-t-butoxycarbonylmethoxy)-imino]]-acetamido-4-N-formylglycinoyl-oxymethyl]-2-azetidinone.
Dicyclohexylcarbodiimide (3.25 g) is added to a stirred mixture of cis-(±)-3-[2'-[(2"-t-butoxycarbonylamino)-4"-thiazolyl]-(Z)-2'-[(1'"-t-butoxycarbonylmethoxy)imino]acetamido-4-hydroxymethyl]-azetidinone (4.5 g), 1 hydroxybenzotriazole 1.216 g), dimethylaminopyridine (122 mg), N-formylglycine (1.62 g) and some 4 Å molecular sieves in methylene chloride (60 ml) and dimethylformamide (6 ml) at room temperature After 2 hours, the precipitated solid is filtered off, washed with methylene chloride (50 ml) and the filtrate is stirred with aqueous sodium bicarbonate (1.89 g sodium bicarbonate in 40 ml water) at room temperature for 15 minutes. The organic layer is taken, dried over sodium sulfate and concentrated under reduced pressure. The residue is passed through the medium pressure silica gel column eluting with 3:1 hexane/ethylacetate followed by ethyl acetate to give the title compound (3.6 g). Melting point: 108°-110° C.
EXAMPLE 17
Cis-(±)-[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(1"-carboxymethoxy)imino]acetamido-4-[N-formylglycinoyloxymethyl]-2-oxo-1-azetidinesulfonic acid monopotassium salt (Compound 7) and cis-±-3-[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(1'"-carboxymethoxy)imino]acetamido-4-[N-formylsulfonic acid glycinoyl-oxymethyl]-2-oxo-1-azetidinesulfonic acid dipotassium salt (Compound 8)
a dimethylformamide-sulfur trioxide solution (2.85 ml of 0.904 M solution) is added t a solution of cis-(±)-3-[2'-[2"-t-butoxycarbonylamino)- 4"-thiazolyl]-(Z)-2'-[(1'"-t-butoxycarbonylmethoxy)-imino]]acetamido-4-N-formylglycinoyl -oxymethyl]-2-azetidinone (1.5 g) in dimethylformamide (5 ml) at 0° C. and stirred for one hour. The ice bath is removed and the solution is kept at ambient temperature for an hour. An additional 1 ml of dimethylformamide-sulfur trioxide complex solution is added. After 45 minutes the reaction is quenched by adding aqueous monobasic potassium Phosphate solution (690 mg monobasic potassium phosphate in 40 ml water) and methylene chloride (50 ml) followed by tetra-N-butylammonium hydrogen sulfate (1.74 g). The organic layer is taken, dried over sodium sulfate and con. centrated under reduced pressure. The residue is dissolved in methylene chloride (10 ml), cooled to 0° C. and trifluoroacetic acid (15 ml) is added with stirring. The ice bath is removed after 2 minutes and the reaction mixture is kept at ambient temperature for 30 minutes. The reaction mixture is concentrated under reduced pressure, washed with hexane (50 ml× 5) to remove the residual trifluoroacetic acid and the residual material was again concentrated under reduced pressure. The residue is dissolved in methanol (10 ml) and passed through Dowex-K + followed by HP-20 resin to give the monopotassium salt (275 mg) and the dipotassium salt (192 mg). Monopotassium salt: 1 H-NMR(δ, D 2 O, Me 2 SiCD 2 CD 2 COO-NA + as a reference) 8.14, 7 0, 5.2, 4.7˜4.53, 4.44, 4.08. Dipotassium salt: 1 H-NMR(δ, D 2 O, Me 3 SiCD 2 CD 2 COO-Na + as a reference) 8.87, 7.0, 5.54, 4.7˜4.5, 4.55, 4.35.
EXAMPLE 18
Cis-(+)-3-[[2'(2"-amino-4"-thiazolyl)-(Z)-2'-(1"-carboxymethoxy)imino]acetamido]-4-[N-formylglycinoyl-oxymethyl]-2-oxo-azetidinesulfonic acid potassium salt (Compound 12).
The optically active title compound is obtained by resolving the enantiomers of cis-(±)-3-phenylmethoxycarboxamido-4-methoxycarbonyl 1(2,4-dimethoxybenzyl)-2-azetidinone. Chem. Pharm. Bull. 32:2-646.2659 (1984). To this racemic mixture (207.3 g) in tetrahydrofuran (500 ml) at room temperature is added palladium black (78.5 g). The hydrogenolysis reaction is carried out under one atmosphere of hydrogen gas. Toluene (100 ml) is added to the reaction mixture and stirred for 15 minutes. The catalyst is removed by filtration and washed several times with tetrahydrofuran. The solvent is evaporated to yield cis-(±)-1-(2'-4'-dimethoxybenzyl)-4-methoxycarbonyl-3-amino-2azetidinone.
The above amino azetidinone is dissolved in acetonitrile (3000 ml) and (+)-di-p-toluoyl-D-tartaric acid (200 g) is added with stirring. The solution is warmed to dissolution and allowed to cool to room temperature. The solid precipitate is then collected by filtration and washed with ice-cold acetonitrile. The solid is recrystallized from acetonitrile to give the tartrate salt of cis-(+)-1-(2',4'-dimethoxybenzyl)-4-methoxycarbonyl-3-amino-2-azetidinone.
The above salt is then dissolved in tetrahydrofuran (1000 ml) and water (400 ml) at 0° C. Sodium bicarbonate (34.9 g) and benzyl chloroformate (26.0 ml) are added with stirring. After one hour at 0° C., the reaction mixture is warmed to room temperature and stirred for 30 min. The reaction mixture is then concentrated under reduced pressure and the aqueous residue is diluted with ethyl acetate (3000 ml) and water (1000 ml). The organic layer is taken and the aqueous layer is rewashed with ethyl acetate (500 ml). The organic layers are combined and washed successively with 2% aqueous sodium bicarbonate, 1N HCl, brine, and 2% aqueous sodium bicarbonate (500 ml each). The organic layer is then dried over sodium sulfate and concentrated under reduced pressure. The resulting material is triturated with ether to give the desired enantiomer, cis-(+)-3-phenylmethoxycarboxamido-4-methoxycarbonyl-1-(2,4-dimethoxybenzyl)-2-azetidinone.
The above enantiomer is treated with ceric ammonium nitrate at 0° C. in acetonitile to yield cis-(+)-3-phenylmethoxycarboxamido-4methoxycarbonyl2-azetidinone. The enantiomer is then reacted under the identical conditions described for Examples 1.5 to yield cis-(+)-3-[2'-(2"-triphenylmethylamino-4"-thiazolyl)-(Z)-2'-(methoxyimino)acetamido-4 -hydroxymethyl-2-azetidinone which is used to produce the title compound following the steps described for Examples 6 and 7.
1 H-NMR(δ, D 2 O, ME 3 S:CD 2 CD 2 CO 2 -Na + as a reference) 8.5, 7.0, 5.5, 4.6, 4.08.
EXAMPLE 19
Cis-(±)-3-[2'-[2"-amino-4"-thiazolyl)-(Z)-2'-(1'"-carboxymethoxy)imino)]-acetamido-4-[L-N-formylalanoyloxymethyl]-2-oxo-1-azetidinesulfonic acid potassium salt (Compound 9)
The title compound is made by a procedure similar to that described in Examples 16 and 17 and substituting L-N-formylalanine for N-formylglycine.
1 H-NMR(δ, D 2 O. ME 3 SiCD2CD2CO 2 -Na as a reference) 8.2, 5.52, 4.65 and 4.58, 5˜4.4, 1.39.
EXAMPLE 20
Cis(±)-3-[2'(2"-amino-4"-thiazolyl)-(Z)-2'-(1'"-carboxymethoxy)imino)]acetamido]-4-[D-N-formylalanoyloxymethyl]-2-oxo-1-azetidinesulfonic acid (Compound 10).
The title compound is made by a procedure similar to that described in Examples 16 and 17 and substituting D-N-formylalanine for N-formylglycine.
1 H-NMR(δ, D 2 O, ME 3 SiCD 2 CD 2 CO 2 -Na as a reference) 8.1, 5.52, 4.7˜4.2.
EXAMPLE 21
Cis-(±)-3-[[2'-(2"-amino-4"-thiazolyl)-(Z)-2'-(1'"-carboxymethoxy)imino]acetamido]-4-[N-glycinoyl oxymethyl]-2-oxo-1-azetidinesulfonic acid (Compound 11).
The titled compound is made by a procedure similar to that described in Examples 16 and 17 and substituting N-t-butoxycarbonylglycine for N-formylglycine. 1 H-NMR(δ, D 2 O, ME 3 SiCD 2 CD 2 CO 2 -Na as a reference) δ7.0, 5.25, 4.97˜4.62, 3.95.
TABLE 1______________________________________ANTIMICROBIAL IN VITRO TESTINGMinimum Inhibitory Concentration -MCG per ML- Com- Com-Organism Name Culture No. pound 7.sup.1 pound 11.sup.2______________________________________Staphylococcus aureus 6675 >128 >128Staphylococcus aureus 3665 >128 >128Staphylococcus aureus 6685 >128 >128Streptococcus faecalis 694 >128 >128Streptococcus pneumoniae 41 64 128Streptococcus pyogenes 152 16 16Citrobacter freundii 3507 0.125 0.25Enterobacter cloacae 9381 64 64Enterobacter cloacae 9382 0.125 0.25Escherichia coli 311 0.06 0.125Escherichia coli 9451 0.125 --Escherichia coli 9379 0.125 0.25Escherichia coli 9380 0.25 0.25Klebsiella oxytoca 9383 0.5 1Klebsiella oxytoca 9384 0.06 0.125Klebsiella pneumoniae 58 0.06 0.125Proteus vulgaris 9679 <0.03 0.125Serratia marcescens 6888 0.25 0.5Pseudomonas aeruginosa 9191 4 8Pseudomonas aeruginosa 6432 8 64Pseudomonas aeruginosa 6676 4 8Pseudomonas aeruginosa 30133 8 16______________________________________ .sup.1 Compound 7 is cis(±)3-[2'(2'amino-4'thiazolyl)-(Z)-2(1''' carboxymethoxy)imino]acetamido4-[N--formylglycinoyloxymethyl2-oxo-azetidiesulfonic acid potassium salt. .sup.2 Compound 11 is cis(±)3-[[2(2'amino-4'thiazolyl)-(Z)-2(1''carboxymethoxy)imino]acetamio4-[N--glycinoyloxymethyl2-oxo-1-azetidine sulfonic acid. ##STR3##
______________________________________STRUCTURE CHARTSCompoundNo. R.sub.4 R.sub.3X M______________________________________1 CH.sub.3 ##STR4## K2 CH.sub.3 ##STR5## K3 CH.sub.3 ##STR6## K4 CH.sub.3 CH.sub.2 NHCO.sub.2 CH.sub.2 C.sub.6 H.sub.5 K5 CH.sub.3 CH.sub.2 NHCOCH.sub.3 K6 CH.sub.3 CH.sub.2 NHCHO K7 CH.sub. 2 CO.sub.2 H CH.sub.2 NHCHO K8 CH.sub.2 CO.sub.2 H CH.sub.2 NH(SO.sub.3 K)CHO K9 CH.sub.2 CO.sub.2 H CH(CH.sub.3)NHCHO K10 CH.sub.2 CO.sub.2 H (D) CH(CH.sub.3)NHCO K11 CH.sub.2 CO.sub.2 H CH.sub.2 NH.sub.2 K12 CH.sub.2 CO.sub.2 H (D) CH.sub.2 NACOH K13 C(CH.sub.3).sub.2 CO.sub.2 H CH.sub.2 NHCOH K14 C(CH.sub.3).sub.2 CO.sub.2 H (D) CH(CH.sub.3)NHCHO K15 C(CH.sub.3).sub.2 CO.sub.2 H (L) CH(CH.sub.3)NHCHO K______________________________________ ##STR7##
|
An antimicrobially active compound of the formula ##STR1## and pharmaceutically acceptable salts thereof: wherein R 1 is hydrogen, --OCH 3 , or --NH--CHO; R 2 is an acyl group derived from a carboxylic acid; R 3 is selected from the group consisting of --CH 2 --, --CH 2 CH 2 --, --CH 2 CH 2 CH 2 --, and --CH 2 CH 2 CH 2 CH 2 -- and when X is NL 2 L 3 then --CH 2 CH 2 --, --CH 2 CH 2 CH 2 --, and --CH 2 CH 2 CH 2 CH 2 -- are optionally substituted with one substituent selected from the group consisting of (C 1 -C 4 )alkyl, (C 1 -C 4 )carboxyalkyl, or (C 1 -C 4 )alkylthio; X is --NL 2 L 3 or a pyrrole of the formula ##STR2## wherein L 1 is hydrogen, --CO--O--CH 2 --(C 6 H 5 ), or SO 3 H; L 2 is hydrogen, or SO 3 H; and L 3 is hydrogen, --CO--(C 1 -C 4 )alkyl; --CH═NH, --C(NH 2 )=NH, --CO--O--CH 2 --(C 6 H 5 ), --COH, or --SO 3 H with the proviso that if one of L 2 or L 3 is --SO 3 then the other is hydrogen.
| 2
|
BACKGROUND OF THE INVENTION
This invention relates to a polish composition which is useful for treating cleaned painted surfaces, and a process for using the same. More particularly, this invention relates to a rinse type polish composition which is useful in automobile washing facilities for effecting a polish on the cleaned surfaces of vehicles, and a process for using the same.
In general, various rinse type polish compositions are known in the prior art. Background of the early investigations in this area may be obtained by referring to Soap and Chemical Specialties, February, 1962, page 72 et seq. U.S. Pat. No. 3,222,213 discloses a formulation which consists essentially of an organic cationic surfactant, an emulsifiable mineral oil and water. U.S. Pat. Nos. 3,497,365, 3,551,168, and 3,756,835 also disclose various improved polish formulations.
Many of the previous polish compositions have shown acceptable performance when commercially utilized in automobile washing facilities, but have been economically undesirable due to their relative high cost and the large amount of active ingredient necessary to accomplish acceptable performance. Thus, a need has existed for such compositions which show an acceptable performance at lower dosage levels of active ingredient.
SUMMARY OF THE INVENTION
It has now been found that by employing certain polyols in polish formulations containing an emulsifiable mineral oil and an organic cationic surfactant, a composition is obtained which may be utilized as a rinse type polish, especially suitable for use in automobile laundries. Such formulations accomplish acceptable performance at lower dosage levels of active ingredients, when compared to prior art compositions which do not contain a polyol.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polyols which are useful in the practice of the present invention are of two general categories. The first category includes diols which are normal or branched chain saturated or mono-ethylenically unsaturated aliphatic hydrocarbons containing from 2 to about 10 carbon atoms. The preferred diols of this category have the general formula ##STR1## wherein R 1 , R 3 , R 4 , and R 5 are independently selected from the group consisting of hydrogen and monovalent, straight or branched chain, saturated or mono-ethylenically unsaturated, aliphatic hydrocarbon radicals having from about 1 to 3 carbon atoms; R 2 is selected from the group consisting of divalent, straight or branched chain saturated or mono-ethylenically unsaturated aliphatic hydrocarbon radicals having from about 1 to about 3 carbon atoms; a, b, and c are independently integers from 0 to 2; provided that the sum of a + c = 2; the total number of carbon atoms being from 2 to about 10.
The second category of polyols includes saturated aliphatic diols which contain from 4 to about 15 carbon atoms and from 1 to about 4 ether linkages. The preferred diols of this category have the general formula
H O R.sub.1 O--(R.sub.2 O).sub.x --(R.sub.3 O).sub.y --(R.sub.4 O).sub.z --H
wherein R 1 , R 2 , R 3 and R 4 are divalent radicals independently selected from the group consisting of ##STR2## and x, y, and z are 0 or 1.
Examples of the polyols of the first category include ethylene glycol, propylene glycol, 2-methyl-2,4-butanediol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, and 1,5-pentanediol.
Examples of the polyols of the second category include di-, tri-, and tetra- ethylene glycol and di-, tri-, and tetra- propylene glycol.
Especially preferred polyols are those of the first category and most preferred are the branched chain glycol type, 2-methyl-2,4-butanediol, 2-ethyl-1,3-hexanediol, and particularly 2-methyl-2,4-pentanediol.
The term emulsifiable mineral oil as used in this application means a paraffinic or naphthenic mineral oil having a viscosity in the range from about 20 to about 200 Saybolt Universal seconds (SUS) at 100° F. Mineral seal oil having a viscosity of about 40 SUS is the preferred emulsifiable mineral oil.
The cationic surfactants which are useful in the practice of the present invention may be fatty amido mono- or di- amines, imidazolines, or imidazolinium quaternaries, or di-fatty alkyl dimethyl quaternary ammonium salts. The term fatty acid or fatty alkyl as used in this application, means, respectively, a straight or branched chain saturated or mono-ethylenically unsaturated aliphatic carboxylic acid or hydrocarbon, containing from about 8 to about 18 carbon atoms.
Especially useful fatty amido amines have the formula ##STR3## wherein R is a monovalent fatty alkyl group, and x is 1 or 2.
Imidazolines which are especially preferred have the formula ##STR4## wherein R is a monovalent fatty alkyl group and B is selected from the group consisting of --H, CH 3 , --CH 2 CH 3 , --CH 2 CH 2 OH, and --CH 2 CH 2 NH 2 .
Imidazolinium quaternaries which are especially preferred have the formula ##STR5## wherein R is a monovalent fatty alkyl group, B 1 and B 2 are independently selected from the group consisting of --CH 3 , --CH 2 CH 3 , --CH 2 CH 2 OH, and --CH 2 CH 2 NH 2 , ##STR6## wherein R is as defined above and A is a halide, acetate, sulfate, ethosulfate, or methosulfate.
The di-fatty alkyl di-methyl quaternary ammonium compounds which are especially preferred have the formula ##STR7## wherein R 1 and R 2 independently are selected from the group consisting of monovalent fatty alky groups, and A is a halide, acetate, ethosulfate or methosulfate.
For the cationic surfactant it is preferred to use a di-fatty alkyl dimethyl quaternary ammonium compound. Most preferred is dimethyldicocoammonium chloride.
The cationic surfactant and mineral oil which are useful in the present invention can be made to form an oil-in-water emulsion. Upon application to a cleaned painted surface the primary ingredients are deposited as a water-repellant film on said surface. The presence of a polyol, as defined above, in such an emulsion allows acceptable performance to be achieved with the use of a small amount of active ingredient in the emulsion.
In practice, a pre-emulsion concentrate is first made by mixing the emulsifiable mineral oil, the cationic surfactant, and the polyol. The components are usually combined so that the pre-emulsion concentrate contains from about 35 to about 70 percent emulsifiable mineral oil, from about 30 to about 50 percent cationic surfactant, and from about 4 to about 20 percent polyol. For both the cationic surfactant and the polyol, the components may be present as single species or as mixtures thereof. All percentages in this application are by weight unless indicated to be otherwise. Preferably, the concentrate will contain from about 40 to about 50 percent emulsifiable mineral oil, from about 40 to about 50 percent cationic surfactant and from about 6 to about 12 percent polyol. Obviously, broad ranges of the components may be utilized and the operability of compositions outside of the scope of the foregoing parameters is dependent primarily upon the specific components utilized and the condition of the water used in forming the subsequent emulsion. Also present in the pre-emulsion concentrate may be various amounts of impurities which do not substantially effect the operability of the concentrate, such as free amine, amine hydrochloride, water, and other production-related impurities. These impurities may be present up to a total of about 10 percent and typically are present in an amount from about 2 percent to about 8 percent.
The pre-emulsion concentrate may also contain from about 0 to about 10 percent, and more typically from about 7.5 to about 10 percent of a supplemental cationic surfactant which functions as an auxiliary emulsifier and reduces the turbidity that may be present in certain specific formulations. Usually the auxiliary emulsifier is a polyethoxylated fatty alkyl amine in which the fatty alkyl group contains from about 12 to about 18 carbon atoms and from about 2 to about 15 ethylene oxide moieties. Particularly preferred are bis(2-hydroxyethyl)tallowamine, polyoxyethylene (5) tallowamine, polyoxyethylene (15) tallowamine, and mixtures thereof. When the cationic surfactant utilized in the practice of the invention is an imidazoline compound, there should be present in the pre-emulsion concentrate one or more of the above mentioned polyethoxylated fatty alkyl amines, as described in U.S. Pat. No. 3,222,213. The amido amine compounds may require similar auxiliary emulsifiers or partial or complete neutralization with a short chain acid such as acetic.
An oil-in-water emulsion is formed from the foregoing pre-emulsion concentrate by admixing said concentrate with water in a weight ratio of concentrate to water of from about 1 to 800 to about 1 to 8000, preferably from about 1 to 3000 to about 1 to 6000.
A typical procedure for achieving the desired dilution of the oil-in-water emulsion in commercial establishments is to combine sufficient concentrate with water to form a preliminary emulsion containing from about 1 to about 4 percent concentrate. From about 2 to about 6 ounces of this emulsion is then continuously and uniformly combined with from about 1 to about 2 gallons of flowing water which is sprayed directly onto the cleaned surface.
The desired oil-in-water emulsion, as defined generally above, is applied, preferably by spraying, onto a cleaned painted surface, in an amount effective to produce beading on said surface, until a beading of water droplets on said surface is observed, and thereafter the droplets are removed from said surface. The foregoing process is an effective means for drying a cleaned surface.
The following examples are illustrative only and are not to be construed as limitations thereon. All percentages and proportions are by weight.
EXAMPLE I
A pre-emulsion concentrate is made by charging to a reactor dicocoamine, 2-methyl-2,4 pentanediol, mineral seal oil and sodium bicarbonate in a weight ratio of 10,000:2036:1303:180, respectively. The reactor is heated to 80°-85° C and methyl chloride, in a weight ratio of methyl chloride to dicocoamine of 32:100, is introduced at a temperature of 80°-85° C while maintaining a pH of 7-9 by the addition of sodium hydroxide if necessary. The reaction is terminated when the free amine and amine hydrochloride is less than 3 percent. The product is then cooled, filtered from by-product salt and diluted with mineral seal oil to produce a concentrate containing 43.2 percent dimethyldicocoammonium chloride, 8.5 percent 2-methyl-2,4-pentanediol, 4.3 percent water, 1-2 percent free amine and amine hydrochloride and 42-43 percent mineral seal oil.
EXAMPLE II
A pre-emulsion concentrate is made by combining the following components in the specified proportions:
______________________________________dimethyldicocoammonium chloride 39.5%mineral seal oil 34.5free amine, amine hydrochloride, and water 8.02-methyl-2,4 pentanediol 8.0polyoxyethylene (5) tallowamine 10.0______________________________________
This example shows a rinse-type polish concentrate formulation of the type shown in Example I, with the addition of an auxiliary emulsifier.
COMPARATIVE EXAMPLE A
For purposes of comparison, a pre-emulsion concentrate is made by combining the following components in the specified proportions:
______________________________________dimethyldicocoammonium chloride 31.2%mineral seal oil 56.4polyoxyethylene (5) tallowamine 10.0free amine, amine hydrochloride, and water 2.4______________________________________
This examples shows a typical rinse-type polish concentrate formulation containing both a cationic surfactant, and an auxiliary emulsifier but with no polyol present.
COMPARATIVE EXAMPLE B
For purposes of comparison, a pre-emulsion concentrate is made by combining the following components in the specified proportions:
______________________________________dimethyldicocoammonium chloride 39.7mineral seal oil 56.9free amine, amine hydrochloride, and water 3.4______________________________________
The example shows a rinse-type polish concentrate formulation containing a cationic surfactant, but with no auxillary emulsifier or polyol present.
The foregoing concentrates were utilized in a commercial automobile laundry and the results are summarized in Table I. In the Table the concentration shown is of the preliminary emulsion which is subsequently further diluted with water when applied to the surface of cleaned automobiles. Approximately 4 ounces of the preliminary emulsion are combined with 1 to 2 gallons of flowing water and the resulting emulsion is sprayed on the cleaned automobiles.
The cars treated in such a manner had their appearance rated on a scale of 1-5, 1 representing a finish which exhibited superior beading, fastest water run off, and minimum towelling time. The ratings shown in parenthesis in Table I are derived from the same data as the ratings not in parenthesis, with the exception that new cars, which generally exhibit excellent finish quality, have been removed from consideration.
From the foregoing Table I, it is apparent that the compositions of Examples I and II exhibit performance which is superior to that of the other compositions, thus demonstrating the advantageous results obtainable from the compositions of the present invention. From Table I it is also apparent that for some specific compositions and water conditions, the presence of an auxiliary emulsifier may diminish the effectiveness of the compositions rinsing formulations.
TABLE I______________________________________Composition of % ConcentrationExample 4% 2% 1%______________________________________I -- 2.2 2.6A 2.6 (2.7) 3.6 (3.8) --B 2.0 3.5 (4.0) 3.4II 2.8 (3.0) 3.1 (3.75) 3.1______________________________________
EXAMPLE III
A pre-emulsion rinse-type concentrate formulation is prepared having the following components and specified proportions:
______________________________________dimethyldicocoammonium chloride 34.1%mineral seal oil 43.5polyoxyethylene (5) tallowamine 10.0water 6.02-methyl-2,4-pentanediol 6.4______________________________________
This formulation is a concentrate of the type within the scope of this invention, but having a supplemental cationic surfactant included in the formulation.
EXAMPLE IV
A pre-emulsion rinse-type concentrate formulation is prepared having the following components and specified proportions:
______________________________________dimethyldicocoammonium chloride 45.5mineral seal oil 44.7water, free amine, amine hydrochloride 1.32-methyl-2,4-pentanediol 8.5______________________________________
This formulation is a typical concentrate of the type within the scope of this invention.
COMPARATIVE EXAMPLE C
A pre-emulsion rinse type concentrate having the following components and proportions is prepared:
______________________________________dimethyldicocoammonium chloride 29.6%polyoxyethylene (5) tallowamine 9.0mineral seal oil 51.5isopropanol and water 9.9______________________________________
The foregoing is representative of a commercially available composition.
COMPARATIVE EXAMPLE D
A pre-emulsion rinse-type concentrate having the following components and proportions is obtained from a commercially available source
______________________________________short-chain alcohol 9mineral oil 49ethoxylated fatty amine 7trimethyl alkyl quaternaryammonium compound 7water 26______________________________________
The foregoing compositions were evaluated in a commercial automobile laundry in accordance with the process described above for the Table I evaluations except approximately 6 ounces of concentrate were mixed with the 1-2 gallons of water. The results of the evaluation are shown in Table II.
TABLE II______________________________________Composition of ConcentrationExample 1/2% 1% 2% 4% 6%______________________________________III -- 2 -- 2 --IV 5 2 -- 2 --C -- 5 4.5 3.5 --D -- -- -- -- 4______________________________________
From the foregoing comparisons in Table II it is apparent that the compositions of the present invention produce acceptable results at concentrations which are less than that necessary for other compositions, not containing a polyol.
|
Improved rinsing formulations are disclosed which comprise an emulsifiable mineral oil, an organic cationic surfactant and a polyol. The formulations may be mixed with water to obtain oil-in-water emulsions which are especially suitable for use in automobile washing facilities.
| 2
|
BACKGROUND OF THE INVENTION
Cured polyepoxides have many desirable properties such as solvent and chemical resistance and firm adhesion to metal substrates. The more recently developed class of vinyl ester resins result from reaction of a polyepoxide and an unsaturated monocarboxylic acid also possess many worthwhile properties, but these latter resins often do not give optimum adhesion to metal (particularly aluminum and tin free steel).
Many formulations have been described in the literature that purport to improve the properties of resins such as the vinyl ester resins.
Those prior reaction products exhibit improved adhesion over prior known compositions. However, all require multicomponent reaction mixtures increasing the complexity of the reaction and the prepared products. Also, the reaction products still leave room for improvement of adhesion to metals.
SUMMARY OF THE INVENTION
The present invention is directed to a radiation curable resin composition composed of a mixture of compounds containing terminal unsaturation, oxirane groups and terminal glycol groups.
DETAILED DESCRIPTION OF THE INVENTION
The curable resin composition is prepared by contacting a polyepoxide, an ethylenically unsaturated monocarboxylic acid and water in certain ratios as will be defined.
Any of the known polyepoxides can be employed in the preparation of the resin composition. Useful polyepoxides are glycidyl polyethers of both polyhydric alcohols and polyhydric phenols, epoxy novolacs, epoxidized esters of fatty acids or drying oils, epoxidized polyolefins, epoxidized di-unsaturated acid esters, epoxidized unsaturated polyesters and mixtures thereof so long as they contain more than one epoxide group per molecule on an average. The polyepoxides may be monomeric or polymeric.
Within the scope of this invention, a number of polyepoxide modifications can be readily made. It is possible to increase the molecular weight of the polyepoxide by polyfunctional reactants which react with the epoxide group and serve to link two or more polyepoxide molecules. A dicarboxylic acid, for example, can be reacted with a diepoxide, such as the diglycidyl ether of a bisphenol, in such a manner so as to join two or more diepoxide molecules and still retain terminal epoxide groups. Other polyfunctional reactants include diisocyanates, dicarboxylic acid anhydrides and those reactants which contain functional groups which will react with the epoxide group. Also, the polyepoxide may contain bromine or other substituents on the molecule, particularly substituted on the aryl group of a polyhydric phenol used in making the polyepoxide.
Where polyhydric phenols are selected to prepare the polyepoxide many structural embodiments are possible. Polyepoxides prepared from polyhydric phenols may contain the structural group: ##STR1## wherein R' is a divalent hydrocarbon radical such as: --CH 2 , --CH 2 CH 2 --, ##STR2## and the like or R' is: --S--, ##STR3## or --O--.
Another class of polyhydric phenols is the novolacs wherein phenols or substituted phenols are linked together with a methylene group.
The choice of novolac resins leads to a separate, well-recognized class of epoxy novolac resins.
Other modifications are well known to those skilled in the art.
The polyepoxides referred to as epoxidized diolefins, epoxidized esters of fatty acids, etc., are generally made by the known peracid method where the reaction is one of epoxidation of compounds with isolated double bonds at a controlled temperature so that the acid resulting from the peracid does not react with the resulting epoxide group to form ester linkages and hydroxyl groups. Preparation of polyepoxides by the peracid method is described in various periodicals and patents and such compounds as butadiene polymers, ethyl linoleate, polyunsaturated drying oils or drying oil esters can all be converted to polyepoxides.
An additional preferred class of polyepoxides are epoxidized cycloolefins. These polyepoxides can be prepared by epoxidation of a cyclic olefinic material by known peracid methods.
While the invention is applicable to epoxy esters and alloys prepared from polyepoxides, generally, preferred polyepoxides are glycidyl polyethers of polyhydric alcohols or polyhydric phenols having weights per epoxide group of 150 to 2000. These polyepoxides are usually made by reacting at least about two moles of an epihalohydrin or glycerol dihalohydrin with one mole of the polyhydric alcohol or polyhydric phenol, and a sufficient amount of a caustic alkali to combine with the halogen of the halohydrin. The products are characterized by the presence of more than one epoxide group, i.e., a 1,2-epoxy equivalency greater than one.
In addition to the epoxidic prepolymers discussed hereinabove, the epoxide materials include also, admixed therewith, an ester having two epoxycycloalkyl groups. Thus, a suitable ester of epoxidized cyclohexanemethanol and epoxidized cyclohexanecarboxylic acid is the diepoxide(3,4-epoxycyclohexyl)methyl 3,4-epoxycyclohexanecarboxylate; this same ester may be indexed under the name 7-oxabicyclo[4.0.1]hept-3-ylmethyl 7-oxabicyclo[4.0.1]heptane-3-carboxylate, and has the formula: ##STR4## Another suitable ester having two epoxycycloalkyl groups may be obtained as an ester of an alkyl-substituted (epoxycycloalkane)methanol and a dibasic acid, for example, bis[(3,4-epoxy-6-methylcyclohexyl)methyl]adipate, which may be named alternatively bis[(4-methyl-7-oxabicyclo[4.1.0]hept-3-yl)methyl]adipate, and which has the formula: ##STR5##
Ethylenically unsaturated monocarboxylic acids suitable for reaction with the polyepoxide include the α,β-unsaturated monocarboxylic acids including, for example, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like.
Also useful as the unsaturated monocarboxylic acids are the hydroxyalkyl acetate or methacrylate half esters of dicarboxylic acids. The hydroxyalkyl groups of the half esters preferably contain from two to six carbon atoms and include such groups as hydroxyethyl, beta-hydroxypropyl, beta-hydroxybutyl and the like. It is also intended to include those hydroxyalkyl groups in which an ether oxygen is present. The dicarboxylic acids can be either saturated or unsaturated. Saturated acids include phthalic acid, chlorendic acid, tetrabromophthalic acid, adipic acid, succinic acid, glutaric acid and the like. Unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, halogenated maleic or fumaric acids, mesaconic acid and the like. Mixtures of ethylenically unsaturated carboxylic acids may be used.
Another essential component in the preparation of the resin compositions is water to hydrolyze some of the oxirane groups to a glycol functionality. This glycol moiety in the composition is essential to attainment of the exceptional adhesion of the composition to metals.
The reactants can be varied within relatively wide ratios to achieve a compositional mixture meeting the objectives of the invention. The unsaturated acid should be present in an amount of 10 to 90 mole percent based on the moles of polyepoxide. Preferably that amount should be from 40 to 80 mole percent with the optimum amount at 50-70 mole percent. The water present in the reaction mixture should be at least about 0.6 equivalents per equivalent of oxirane groups. Larger amounts of water than about 1.6 equivalents may be used but will generally require the removal of excess water from the final product. The use of less water than 0.6 equivalents produces insufficient hydrolysis to provide a resin mixture having the desired level of glycol groups. The remainder of the oxirane groups will remain unhydrolyzed.
The reaction is conducted in the presence of a catalyst such as an alcoholate, sodium carboxylate, phosphonium, ammonium or arsonium salts, a tertiary amino phenol or a trivalent chromium salt. Although the catalyst may be varied within wide limits as, for example, from 2×10 -3 to 4.5×10 -4 moles chromium triacetate, the optimum concentration is between 0.3 to about 0.35 millimoles of trivalent chromium or its equivalent of other catalyst per equivalent of epoxide.
The reaction can be run within a wide range of reaction temperatures such as from 90°-140° C. A generally optimum range for acceptable reaction time and product distribution is from about 100° C. to 125° C. Lower temperatures result in unnecessarily long reaction times.
Judicious selections of such parameters will be easily made by the skilled worker to provide optimum reaction rates and products.
Typically, the reaction product will be a mixture of components of (1) compounds containing the same functional moiety and (2) compounds having one each of two functional groupings as above described. For example, in a reaction of the diglycidyl ether of bisphenol A, acrylic acid and water, the following six compounds would be present: ##STR6## The concentration of each of the species in the mixture may be varied within wide limits. It appears that the hydrolyzed acrylate and hydrolyzed epoxide must be present in significant amounts to attain a full spectrum of good properties. A laboratory mixture prepared from the dihydrolyzed species, the diacrylate and the diepoxide, each species having been previously prepared separately, did not result in a product with good properties. When the reactant proportions as outlined above are utilized, a suitable mixture of the various species is produced to provide a product with desirable properties.
Alternatively, a useful product can be prepared by blending the diacrylate, and epoxyacrylate and/or diepoxide species and partially saponifying the acrylate groups of that mixture.
For use in coating formulations, the reaction product may be blended with a reactive diluent which is usually an ethylenically unsaturated monomer that is copolymerizable with that product.
A wide selection of copolymerizable monomers containing the >C═CH 2 group is available for use as the reactive diluent. Representative species include styrene, vinyl toluene and the esters of acrylic and methacrylic acids; such as butyl, 2-ethylhexyl, phenoxyethyl, dicyclopentyl, tetrahydrofurfuryl and benzyl esters. Also included are vinyl acetate, diallyl maleate, dimethallyl furmarate and vinyl carboxylic acids; such as the half ester of 2-hydroxyethyl acrylate and a dicarboxylic acid.
Preferred as reactive diluents are the acrylic and methacrylic esters of saturated alcohols and the hydroxyalkyl esters.
The compositions of this invention are curable upon exposure to actinic light of ultraviolet or visible wavelength. Suitable sources include, but are not limited to, carbon arcs, mercury vapor arcs, pulsed xenon lamps, fluorescent lamps with special ultraviolet light emitting phosphors, argon glow lamps and others that are well known.
To be curable at an acceptable rate by actinic radiation requires the incorporation of a photoinitiator in the formulation. Because the mixture contains both olefinic unsaturation and oxirane groups, it is most advantageous to have a photoinitiator that will function both as a free radical initiator and as an ionic catalyst precursor. Basically such compounds or blends of compounds under actinic exposure form free radicals and also generate a hydrohalide.
Typical of such catalysts is p-tert-butyl-α,α,α-trichloroacetophenone. Also such catalyst systems as those described in U.S. Pat. No. 4,069,054 are bifunctional in this manner. Those systems are an aromatic sulfonium compound sensitized with an aromatic tertiary amine or an aromatic polycyclic compound, all as further defined in the patent. Those teachings are incorporated herein by reference.
Also conventional benzoin ether photoinitiators used in conjunction with halogenated solvents will result in sufficient HCl generation to result in products meeting the objectives of the invention.
Catalysts which only generate free radicals under light exposure will produce hard, tack-free coatings, but such coatings will usually result in coatings that are somewhat deficient in adhesion and one or more properties.
The compositions are fabricated into the desired shape as, for example, by casting or otherwise applying a coating onto a substratum. After shaping, the uncured composition is exposed to a light source to cause polymerization. The light source can be any ultraviolet actinic radiation such as that produced from a mercury, xenon or carbon arc lamp. The compositions are well adapted to imaging processes, wherein parts of the uncured coating are masked and then exposed to the radiation source so that only those exposed portions are cured. The unexposed parts remain uncured and can be washed away with suitable solvents to leave a reversal image.
These compositions usually exhibit excellent adhesion to such substrates with only an actinic radiation cure. This adhesion is obtained without sacrificing the other superior chemical and physical properties of such systems. In addition to overcoming the problems associated with acrylic systems, the compositions of this invention overcome difficulties associated with curing thick sections of epoxies. Although generally useful coatings are obtained without a thermal post baking step, there are some compositions, particularly with certain reactive diluents, where that step is important to achieve optimum adhesion. When those reactive diluents are employed with other resins than those of this invention, adhesion is not obtained even with a thermal post bake.
The invention will be more apparent from the following illustrative examples.
EXAMPLE 1
A resin composition was prepared by mixing together 250 grams (1.35 moles) of a diglycidyl ether of bisphenol A (EEW=180 to 185; 23 percent epoxy content), 37 milliliters (0.54 mole) acrylic acid, 0.5 gram (4.5×10 -3 moles) hydroquinone and 0.5 gram (4.0×10 -3 moles) p-methoxyphenol. The mixture was made in a three-neck 500 milliliter round bottom flask equipped with an overhead air driven stirrer, a reflux condenser and a thermometer. When the contents had been thoroughly mixed, a catalyst solution composed of 0.65 gram (1.1×10 -3 moles) basic chromium acetate and 40 milliliters (2.2 moles) water was added. The mixture was heated at 110° C. for 3.5 hours after which the resin was sparged with nitrogen for 1 hour at 110° C.
A portion of the above resin (0.4995 gram) was mixed with 0.4985 gram dicyclopentadiene acrylate and 0.0312 gram p-tertbutyl-α,α,α-trichloroacetophenone (Trigonal P-1). The mixture was spread on Parker aluminum panels with a No. 7 Meyer wire wound rod and cured by passing under a 200 watt per linear inch Hanovia mercury arc lamp at a rate of 100 feet per minute. After 10 passes, the coating had become tack free.
The panels were tested for adhesion by scratching 10 straight lines across the panel and 10 lines at right angles to provide 100 squares. Strips of No. 610 Scotch brand tape were stuck to the coating and pulled away from the coating. The number of squares without any coating removed is the precentage adhesion.
When so tested, the composition of this example showed 100 percent adhesion.
EXAMPLE 2
A series of reaction products were made according to the method of Example 1 but varying the catalyst concentration and water level. The reaction time was determined by determining the percent carboxyl in aliquots withdrawn from the reaction mixture. The reaction was considered complete when the percent carboxyl was less than one percent. At that time, the mixture was sparged with nitrogen for an additional hour.
Some samples were blended with dicyclopentadiene acrylate, others with phenoxyethyl acrylate in a 1 to 1 ratio with the resin. All were cast as coatings on Parker aluminum panels and cured as per the previous example. Adhesion was measured with the described cross-hatch test. The results are shown in Table 1. In the table the percent of each of the components in the reaction product was determined by liquid-liquid chromatography.
TABLE 1__________________________________________________________________________PRODUCTS FROM REACTION OF 1 EQUIVALENTEPOXY RESIN WITH 0.6 EQUIVALENT ACRYLIC ACID ##STR7## Reac- tion Time (Hrs.) DH (%) HA (%) HE (%) DA (%) EA (%) DE (%) ##STR8## ##STR9##__________________________________________________________________________1.62 7.5 20.5 47.7 2.2 29.0 2.6 -- 3 100 100 100 (DCPDA) 5 80 100 100 (EPhA).81 4.5 4.1 18.1 6.9 34.5 29.6 6.8 4 15 98 100 (DCPDA) 5 0 0 100 (EPhA).81 4.0 4.8 19.5 8.9 37.4 24.6 4.7 4 100 100 100 (DCPDA) 5 100 100 100 (EPhA).41 2.5 1.3 8.0 4.0 33.4 41.1 12.2 4 0 50 100 (DCPDA) 5 0 25 100 (EPhA)__________________________________________________________________________ .sup.1 Number of passes under 200 w/Lin. inch Hg arc lamp at 100'/min. to develop marfree surface In the first two listed samples catalyst conc. was 0.62 moles Cr(OAc).sub.3 /eq. epoxide; in last two samples conc. was 0.31 Cr(OAc).sub.3 /eq. epoxide.
EXAMPLE 3
Compositions were prepared from a composition from a diglycidyl ether of bisphenol A having an epoxy equivalent weight of 180 to 185 and a viscosity of about 10,000 centipoises and acrylic acid. The amount of acid was varied to provide different levels of ester content in the product.
About 1 equivalent of water per equivalent of oxirane was used. That included the water from the addition of 0.12 percent of 33 percent aqueous chromium chloride.
The resin was prepared as in Example 1. Samples of the resin were mixed to provide a 50 percent resin mixture with either dicyclopentadiene acrylate or phenoxyethyl acrylate as reactive diluents and p-tertbutyl-α,α,α-trichloroacetophenone as catalyst. The compositions were then coated on various substrata and exposed to ultraviolet light as in the previous examples. Some were given a thermal postbake at 160° C. The adhesion was evaluated as before.
The results are shown in Table II.
TABLE II__________________________________________________________________________UV CURED COATING PROPERTIES OF HYDROLYZED RESINSDCPDA.sup.1 EPh-A.sup.2Resin(% Acry- 100% 100%lated 60% 70% 80% 90% (XD-9002) 60% 70% 80% 90% (XD-9002)__________________________________________________________________________Cure Rate 4 4 3-4 3 3-4 4-5 3-4 3-4 3 3ReverseImpact 20-30 40-50 30 50-60 < 10 80-90 60 50-60 40 30% AdhesionAl (No Bake) 1 Hour 90 0 0 0 0 0 0 0 0 024 Hours 100 100 97 97 0 0 0 0 0 0Al (160° C.)2 Minutes 100 100 100 100 100 100 100 65 100 04 Minutes -- -- -- -- -- -- -- 95 -- 0ETP (No Bake).sup.3 1 Hour 0 0 0 0 0 0 0 0 0 024 Hours 0 0 0 0 0 -- -- -- -- --ETP (160° C.)2 Minutes 100 100 100 100 100 70-80 20-30 0 0 04 Minutes -- -- -- -- -- 100 25-30 20 0 0TFS (No Bake).sup.4 1 Hour 0 0 0 0 0 0 0 0 0 024 Hours 0 -- -- -- -- 0 0 0 0 0TFS (160° C.)2 Minutes 90-100 30-50 0 0 0 0 0 0 0 04 Minutes -- 100 100 100 100 0 0 0 0 0__________________________________________________________________________ .sup.1 50% DCPDA + 50% Resin .sup.2 45% EPHA + 50% Resin .sup.3 ETP = ElectroTin-Plate .sup.4 TFS = TinFree Steel
|
An ultraviolet light curable resin composition comprises a mixture of entities including a polyepoxide, a partial or complete unsaturated ester of the same polyepoxide, and a partial or complete hydrolysis product of the same polyepoxide. This resin composition exhibits improved adhesion to metals.
| 2
|
BACKGROUND OF THE INVENTION
The invention is based on an apparatus for governing the idling rpm of an internal combustion engine of an internal combustion engine. Such an apparatus has been set forth in U.S. Pat. No. 4,724,349, in which a hollow shaft having a rotary armature and a rotary slide valve that controls the bypass line is supported on a stationary shaft that is retained in a connecting body disposed on one end in a lid-like housing part and on the other in a cup-shaped housing part. Because of the large tolerances required, this kind of support of the rotary slide valve necessitates relatively large play between the circumference of the rotary slide valve and the wall of the pivoting space into which the rotary slide valve protrudes; otherwise, the rotary slide valve, if it is not supported 100% coaxially with the pivoting space, might scrape the wall of the pivoting space. Because of the pressure drop that prevails between atmospheric pressure and the negative pressure prevailing when the engine is running, air incorrectly flows via this undesirably large play between the circumference of the rotary slide valve and the wall of the pivoting space and undesirably impairs the governing process.
OBJECT AND SUMMARY OF THE INVENTION
The apparatus according to the invention has the advantage over the prior art of providing more precise support of the rotary slide valve, which makes it possible to reduce the tolerances of the rotary slide valve and pivoting space, which in turn results in less play and thus less incorrect air, and finally improves the accuracy of the idling rpm governing process. At the same time the relatively tight separation of the control motor from the pivoting space prevents a further exchange of air between the pivoting space and the interior of the control motor, which would also affect the governing accuracy and would soil the control motor.
It is particularly advantageous to join the two housing parts with a screw connection; as a result, the precise guidance between the two parts, and hence the coaxial support of the rotary slide valve with respect to the pivoting space are maintained during installation.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE of the drawing shows an exemplary embodiment of the invention in simplified fashion.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the apparatus shown in the drawing for governing the idling rpm of an internal combustion engine, combustion air flows in the direction of the arrow 1 through an air intake tube 2, past a throttle valve 3 serving as a throttle device, to the engine, not shown. Communicating with the air intake tube 2 is a bypass line 5 which bypasses the throttle valve 3; the flow cross section of the bypass line 5 is variable by means of the apparatus 6 by means of a throttle device embodied as a rotary slide valve 7. The apparatus 6 is triggered by an electronic control unit 8, to which a supply voltage furnished by a vehicle battery is applied at 10, an engine rpm signal picked up from the ignition distributor of the engine is applied at 11, an engine temperature signal is applied at 12, and a voltage representing the position of the throttle valve 3, furnished for instance by a potentiometer connected to the throttle valve, is applied at 13. Further engine operating characteristics may also be fed to the electronic control unit 8 as needed.
Serving as the control motor for the apparatus 6 in the present exemplary embodiment is a collectorless electric motor 15, which is triggerable by the electronic control unit 8 as a function of engine operating characteristics via a plug 16. In the excited state, the electric motor 15 rotates a shaft 17 which is rotatably supported via a first roller bearing 18 and a second roller bearing 19. The second roller bearing 19 is pressed into a blind bore 20 in the bottom 21 of a cup-shaped housing part 22 of the apparatus 6 On an end remote from the second roller bearing 19, the rotary slide valve 7, which is embodied as a tubular segment that protrudes into a pivoting space 24 embodied in a lid-shaped housing part 24 and intersecting the bypass line 5 is connected to the shaft 17 in a manner fixed against relative rotation with respect to the shaft 17. An inflow fitting 26 to the air intake tube 2 upstream of the throttle valve and a outflow fitting 27 to the air intake tube 2 downstream of the throttle valve communicate with the pivoting space 24. The circumference of the rotary slide valve 7 embodied as a tubular segment protrudes as close as possible to the wall of the pivoting space 24. In the wall 28 of the pivoting space 24 oriented toward the inflow fitting 26, at least one control opening 29 is recessed out; this opening can be opened to a variable extent by the rotary slide valve 7. The rotation of the rotary slide valve 7 by the electric motor 15 is effected counter to the force of a spring element, embodied for example as a spiral spring 32, which is connected at its inner end to the shaft 17 and at its outer end to the lid-shaped housing part 23. In the non-excited state of the electric motor 15, the spiral spring 32 turns the shaft 17 into a position in which the control opening 29 is not completely closed by the rotary slide valve 7, so that in this position a cross section sufficient for emergency operation remains open; by way of this cross section, air or a fuel-air mixture can flow through the bypass line into the air intake tube 2 from upstream to downstream of the throttle valve 3. In this operating state, the rotational position of the rotary slide valve 7 can be determined by an adjustable stop, not shown.
The rotary slide valve 7 serving as a throttle device is secured with a hub 34 to the shaft 17, from whence a transmission disk carrying a throttle element 35 extends radially embodied as a tubular segment, of the rotary slide valve 7 that opens the control opening 29 to a variable extent. A through bore 38 is formed in the lid-shaped housing part 23; the shaft 17 protrude all the way through the bore 38, and the throttle element 35 extends partway into the bore 38, both with as little radial play as possible with respect to the wall of the through bore 38. Remote from the pivoting space 24, the through bore 38 is adjoined by a bearing bore 39 of larger diameter, into which the first roller bearing 18 is pressed. In a known manner, the first roller bearing 18 has covering disks 40 that cover the roller bodies, so that virtually no exchange of media takes place via the first roller bearing 18 in the axial direction, between the side of the first roller bearing 18 oriented toward the rotary slide valve 7 and the side oriented toward the electric motor 15. Remote from the rotary slide valve 7, the first roller bearing 18 is engaged by a retaining disk 42 which protrudes partway past the first roller bearing 18 and is fixable in the lid-shaped housing part 23 by means of threaded screws 43 so that the retaining disk 42 braces the first roller bearing 18 in the axial direction The lid-shaped housing part 23 has an axially extending cylindrical guide section 45, upon which the open tubular end 46 of the cup-shaped housing part 22 is slipped tightly with little play; this housing part 22 for instance has radial steps 47 having axial bores 48, through which the retaining screws 49 protrude; on their other end, these screws 49 engage threaded bores 50 in the lid-shaped housing part 23 and assure a firm connection between the cup-shaped housing part 22 and the lid-shaped housing part 23. The connection of the two housing parts 22, 23 may also be accomplished in some other manner, however.
A rotary armature 52 is also secured to the shaft 17, located inside a winding 53 of the electric motor 53. The winding 53 is supported inside the cup-shaped housing part 22 and is pressed in the axial direction by plate springs 54 against a support body 55 resting on the housing bottom 21; the support body 55, made of plastic, also encompasses the plug 16, which protrudes in a sealed manner from the housing bottom 21. Inside the cup-shaped housing part 22, the plate springs 54 are supported via a shim 57 on a split clamping ring 58, which rests in an indentation in the cup-shaped housing part.
The installation of the apparatus is effected by first pressing the rotary slide valve 7 onto the shaft 17 and then superfinishing its jacket face. Next, the first roller bearing 18, a spacer bushing 59 retaining the inner end of the spiral spring 32, and the rotary armature 52 are pressed onto the shaft 17. Now the first roller bearing 18, with the elements secured to the shaft 17, is introduced into the bearing bore 39, and after adjustment of the spiral spring 32 is fixed in its position by means of the retaining disk 42. The second roller bearing 19, the support body 55, the winding 53, the plate spring 54, the shim 57 and the clamping ring 58 are installed in the cup-shaped housing part 22. After that, the two housing parts 22, 23 are united and firmly connected to one another by means of the screws 49. The embodiment of the apparatus 6 according to the invention makes it possible to have the smallest possible tolerances of the various elements of the apparatus so that the rotary slide valve 7 faces the wall of the pivoting space 24 with very little play, and leakage at the rotary slide valve is kept very slight. Uniting the two housing parts 22, 23 entails no risk of undefined shifting at the rotary slide valve 7. The minimally slight radial play between the circumference of the transmission disk 35 and the through bore 38, along with the covering disks 40 on the first roller bearing 18, also prevent an exchange of air between the interior of the electric motor and the bypass line 5, and hence prevents soiling of the control motor.
The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
|
An apparatus for assisting in governing the idling rpm of an internal engine including a bypass line that bypasses a throttle valve in an air intake tube. A rotary slide valve secured to one end of a shaft which is controlled by a motor is rotatable in the bypass line to adjust air flow through the bypass line. The bypass line is integral with a lid-shaped housing part in which roller bearings juxtaposed the rotary slide valve is secured. The upper end of the shaft is rotatable in bearings carried by an upper housing part. The housing parts are secured together in axial alignment with each other.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 USC 119 from Italian Patent Application No. N. MI2011A002046, filed on Nov. 11, 2011, incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a yarn storage feed device in accordance with the introduction to the main claim. In particular, the invention relates to a yarn storage feed device able to measure with absolute precision the fed yarn quantity and the yarn quantity present on the drum.
BACKGROUND OF THE INVENTION
[0003] Various types of yarn feed devices or feeders are known in which the yarn originating from a spool or bobbin is deposited onto a fixed drum loaded by an external member driven by its own motor, or onto a rotating drum from which it is withdrawn by the textile machine. In these feeders a system has necessarily to be provided for measuring or counting the number of turns present on the drum such that the yarn stock present on this latter remains virtually constant, and to prevent it from being totally consumed by the machine, with obvious problems for the operation thereof.
[0004] Various methods for measuring the yarn quantity (or number of turns) present on the drum are known. A first of these utilizes the reflection of light generated by an emitter and received by a corresponding receiver which are associated with the feeder. One or two reading zones (comprising emitters and receivers) are used to verify that at least one turn is present within them. Usually, one is positioned at the drum entry (yarn inlet zone) and one at the drum exit (yarn outlet zone) to control the so-called minimum stock and maximum stock respectively.
[0005] Feeders provided with this type of control are however able to ensure only that the number of turns is within a given range, but are not able to know their exact number (with the consequent impossibility of knowing how much yarn is stored on the drum, of which the lateral surface area is known).
[0006] The aforedescribed reflection method also has the limit of its well known dependence on the colour of the yarn to be monitored, and which can negatively affect the effectiveness of sensing the yarn by the optical elements utilized by the method under examination.
[0007] Feeders are also present in which the turns unloaded from the drum (and hence the fed yarn quantity) can be counted, again by reflection, however these known devices also present the limit that the reading resolution is strongly influenced by the yarn colour and by any dirt and dust deposits on the optical elements by which the number of turns is measured.
[0008] Other feed devices comprise optical elements inserted into a single emitter/receiver member and hence do not comprise separated emitter and receiver portions. This emitter/receiver member is of barrier operation and is able to measure the yarn quantity which has moved in front of it (i.e. the yarn quantity fed and hence the yarn quantity remaining on the drum), however as it does not know the exact position of the yarn within the sensor it is unable to know the yarn position at the feeder outlet, consequently it is unable to offer optimal resolution and precision.
[0009] Other feeders comprise mechanical solutions using mechanical lever detectors to which sensors (proximity sensors, Hall sensors) are connected to determine a minimum and a maximum yarn stock on the drum.
[0010] Such solutions again do not enable the number of turns present on the drum to be known exactly; moreover, the mechanical action of the levers modifies the yarn tension, with obvious repercussions on the yarn fed to the textile machine.
SUMMARY OF THE INVENTION
[0011] An object of the invention is to provide a feed device able to measure with absolute precision the yarn stored on the drum and simultaneously the yarn quantity withdrawn by the textile machine.
[0012] Another object of the present invention is to provide a device able to monitor a yarn feed which does not suffer from those limits of reflection-operated optical solutions related for example to the yarn colour and to dirt accumulation.
[0013] A further object of the present invention is to provide a device which is not influenced by the presence of dust or the like, by being subjected to cleaning by yarn passage along the device.
[0014] Another object of the present invention is to provide a device able to measure with high resolution the yarn quantity absorbed (AYL) by the textile machine.
[0015] A further object of the present invention is to provide a device which does not influence the yarn during its passage from the feeder to the textile machine.
[0016] Another object of the present invention is to provide a device able to sense the lack of yarn or its breakage and possibly to indicate this to the textile machine.
[0017] A further object of the present invention is to provide a device able to count with absolute precision the number of turns deposited on the drum during its loading, starting from the unloaded drum and during all the subsequent operative stages of withdrawal by the textile machine.
[0018] These and other objects which will be apparent to the expert of the art are attained by a feed device in accordance with the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will be more apparent from the accompanying drawings, which are provided by way of non-limiting example and in which:
[0020] FIG. 1 is a perspective view of a device formed in accordance with the invention;
[0021] FIG. 2 is a section therethrough on the line 2 - 2 of FIG. 1 ;
[0022] FIG. 3 is a front view of the section of FIG. 2 ;
[0023] FIG. 4 is a section on the line 4 - 4 of FIG. 1 ;
[0024] FIG. 5 is a section on the line 5 - 5 of FIG. 4 ;
[0025] FIG. 6 is a view similar to that of FIG. 4 , but of a variant of the invention; and
[0026] FIG. 7 is a section on the line 7 - 7 of FIG. 6 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] With reference to said figures, a feed device according to the invention is indicated overall by 1 and comprises a casing 2 provided with a fixing bracket 3 to enable the device to be fixed to a support (not shown) associated with, or close to, a textile machine (not shown).
[0028] The casing 2 carries a rotary member or drum 5 driven (in any known manner) by its own electric motor or actuator 6 (with hollow shaft 6 A) contained within the casing 2 . A yarn F is wound about this drum before leaving the feed device and reaching the textile machine; the yarn F forms a plurality of turns 7 on the drum 5 to hence define a yarn stock for the machine such as to always enable its optimal operation even in the presence of discontinuous yarn withdrawals by said machine, for producing a particular article (for example a mesh).
[0029] The yarn F entering the device 1 cooperates with one or more thread guides 10 (only one being shown in the figures), for example of ceramic, which define its trajectory in entering said device such as to prevent the yarn F from coming into contact with the casing 2 (hence undergoing damage or creating overtensions deleterious for the proper operation of the device 1 and for correct yarn feed to the textile machine).
[0030] The feed device 1 preferably presents an entry yarn brake 11 and a tension sensor 12 , of known type and therefore not described. The thread guide 10 and the yarn brake 11 project from the casing 2 .
[0031] The feeder 1 presents an optical sensor 13 to measure the quantity of yarn F on which the feeder operates. The sensor 13 comprises a first part 15 and a second part 16 surrounding the first; the first part is defined by a part 17 (totally or partly, for example in a lateral surface 22 thereof, of any known light transparent material), disposed coaxially to the rotary drum 5 and containing a plurality of light emitting members or transmitting photodiodes 18 . The part 17 is supported by the casing 2 via a tube 19 positioned within the hollow shaft 6 A and fixed at one end 18 A to this casing. The cable for handling the necessary signals sent and received by the sensor 13 passes within the tube.
[0032] The photodiodes 18 are associated with an electronic circuit or electronic card 21 contained in the part 17 which is present in a stationary position at one end of the drum 5 from which the yarn F leaves to reach the textile machine.
[0033] The second part 16 of the sensor 13 , also stationary, is defined by a hollow annular part 23 present at the casing 2 . The part 23 comprises at least one transparent portion 26 facing the first part 15 and containing a plurality of receiver photodiodes 30 , of a number equal to the number of transmitter photodiodes 18 and disposed within the part 16 such as to receive the light signals emitted by the corresponding transmitter 18 (for example such as to face these emitters).
[0034] The receivers 30 are also associated with an electronic circuit or card 33 inserted into the part 16 and connected electrically to a control unit 35 of the device 1 to control the feeder operation.
[0035] The unit 35 , in particular, cooperates with a memory unit (not shown) in which the “physical” data of the rotary drum 5 , i.e. its diameter, are contained; the unit 35 also commands and controls the operation of the motor 6 , of which the rotational velocity is hence always known by known control elements (for example Hall sensors).
[0036] During use of the device 1 , the yarn F unwinds from a corresponding bobbin or spool (not shown), and passes through the thread guide 10 and the yarn brake 11 .
[0037] At this point the yarn F is wound onto the drum for a predetermined number of turns 7 (possibly programmable); the purpose of this drum is to feed the yarn F by withdrawing it from the spool in order to feed it to the textile machine, while at the same time separating said yarn present on the drum such that the individual turns 7 are unable to superimpose on and/or touch each other.
[0038] Before abandoning the device, the yarn F passes through the sensor 12 which, by known methods, measures its tension, then it possibly passes through a further braking member (not shown) which further determines and controls its braking.
[0039] In proximity to its point of exit from the drum 5 , the yarn F passes through the optical sensor 13 shown in greater detail in FIG. 5 . By way of example, this shows four transmitters (indicated by 18 A, B, C, D) and four receiver photodiodes ( 30 A, B, C, D), the yarn F withdrawn by the textile machine (and shown as a circumference as it detaches from the drum 5 ), and the parts of the sensor 13 .
[0040] The photodiodes 18 and 30 determine four light rays or beams which the yarn F interrupts by passing in front of them, i.e. “light barriers” which are indicated in FIG. 5 by A, B, C, D.
[0041] The suitably conditioned signal (i.e. amplified and filtered by known electrical/electronic members, not shown, associated with the card 33 ) of each receiver element 30 A, B, C, D is fed to the control unit 35 of the entire device. This control unit, by analyzing the state of each barrier and knowing the drum rotation direction, is able to verify the yarn position and to know if the yarn has been loaded onto or unloaded from the drum, during the operating stages of the textile machine. In this respect, it will be assumed that the drum 5 on which the yarn F is deposited rotates clockwise; when the control unit 35 senses a barrier activation sequence (i.e. the sequence of interruption of light beams between the pairs of transmitter photodiodes and receivers 18 A, B, C, D and 30 A, B, C, D) of the type A→B→C→D→A→B→C . . . , it determines that this yarn has been loaded on the drum and defines this sequence as a LOAD sequence.
[0042] When the electronic control unit 35 senses a barrier activation sequence of the type D→C→B→A→D→C . . . , it determines that this yarn F has been unloaded from the drum 5 and defines this sequence as an UNLOAD sequence.
[0043] It is therefore evident that by utilizing the data originating from the optical sensor 13 and by knowing and regulating the velocity and position of the feed drum, the control unit 35 is able to perform the following operations:
[0044] 1) during the loading of the device 1 (sequence in which the yarn is wound onto the drum starting from a drum 5 unloaded condition), the unit 35 counts with absolute precision the number of turns 7 loaded, from which the yarn quantity in mm available as stock can be obtained with precision. In this respect, the control unit 35 causes the drum 5 to rotate at a fixed or variable velocity (by commanding and controlling the motor 6 in any known manner) and monitors the optical sensor 13 , to halt the movement of the drum 5 as soon as it has counted a number of change-overs (A→B, B→C, . . . ) equal to four times the number of revolutions to be carried out.
[0045] 2) The unit 35 senses that the textile machine has begun to withdraw yarn from the feeder when, by analyzing the barrier activation sequence, it determines that an UNLOAD sequence is underway. In response to an UNLOAD sequence, this unit begins to rotate the drum 5 such that the number of turns 7 present as stock remains constant and equal for example to a possibly programmable predetermined value.
[0046] In particular, the control unit 35 increases o decreases the velocity of the motor 6 which controls the drum in response to an UNLOAD sequence or LOAD sequence respectively, in accordance with known control algorithms (for example P, PI, PD, PID), by closing a control loop for the yarn quantity present on the drum.
[0047] Then by processing the data relative to drum velocity and position and the state of the optical sensor 13 , the control unit always known with absolute precision the yarn quantity present on the drum (stock) and the yarn quantity withdrawn by the machine in real time.
[0048] The yarn quantity present on the drum (known hereafter as REAL TIME YARN STOCK) is in fact the algebraic sum of the UNLOAD and LOAD sequence with respect to the initial yarn quantity known as the YARN STOCK.
[0049] For example, assuming that the drum 5 has a linear development equal to 200 mm and assuming that during the loading stage the device has loaded ten turns and hence 2000 mm of yarn (turn number×development→10×200=2000), then at each UNLOAD sequence a value of 50 mm (development/number of sensors→200/4=50) is subtracted from the yarn quantity present on the REAL TIME YARN STOCK, whereas at each LOAD sequence a value of 50 mm is added.
[0050] A brief numerical example follows:
[0000]
SENSOR
YARN
REAL TIME
SEQUENCE
CODE
STOCK
STOCK
2000
2000
A→B
LOAD
2000
2050
B→C
LOAD
2000
2100
C→B
UNLOAD
2000
2050
[0051] The yarn quantity withdrawn by the textile machine is given by the difference between the initial yarn quantity YARN STOCK and the actual yarn quantity REAL TIME YARN STOCK added to the number of drum revolutions.
[0052] Let us imagine that the control unit 35 does not cause the drum 5 to rotate in order to reload the yarn withdrawn by the machine; in this case the withdrawn yarn quantity (ABSORBED YARN QUANTITY AYL) must be incremented by 50 mm for each UNLOAD pulse.
[0053] A numerical example follows:
[0000]
SENSOR
REAL TIME
FED YARN
SEQUENCE
CODE
YARN STOCK
QUANTITY
2000
0
B→A
UNLOAD
1950
50
A→D
UNLOAD
1900
100
D→B
UNLOAD
1850
150
[0054] At the moment in which the control unit 35 begins to cause the drum 5 to reload from the bobbin or spool those turns withdrawn by the machine, the yarn quantity (AYL) is given by the algebraic sum of the YARN STOCK and the REAL TIME YARN STOCK to which a quantity of 200 mm (drum development) must be added for each motor revolution. This is shown in the following table.
[0000]
REAL TIME
SENSOR
YARN
MOTOR
FED YARN
SEQUENCE
CODE
STOCK
R.P.M.
QUANTITY
2000
0
0
B→A
UNLOAD
1950
0
50
A→D
UNLOAD
1900
0
100
D→A
LOAD
1950
1
250
[0055] From the previously given examples it is apparent that the unit 35 is able to measure with absolute precision the value of the stock of yarn F and the yarn quantity absorbed (AYL) by the textile machine.
[0056] It should be noted that the resolution of the two measurements can be improved; for example, the number of optical barriers can be incremented, such as to reduce the minimum increment and decrement step calculated as the drum development divided by the number of barriers.
[0057] An encoder can be used to know the exact position of the motor 6 and hence of the drum 5 such that the contribution given by the rotation of the motor 6 in the calculation of the fed yarn quantity is not an exact multiple of the drum development, but a function of its position (hence also taking account of the fractions of a revolution, with greater encoder resolution and greater measurement resolution).
[0058] For example by using a 4096 position encoder, precisions can be achieved which are less than one tenth of a millimetre.
[0059] One of the possible embodiments of the invention has been described; others are however possible in the light of the preceding description. For example, the number of barriers could be greater or less than four, odd or even, and comprise at least one pair of emitters and at least one pair of receivers; obviously, as the number of barriers increases, the counting precision varies, as already indicated. Moreover, the barriers could operate not “by interruption” but “by reflection”; hence in this latter case, each transmitter and the corresponding receiver lie on the same part 15 or 16 of the sensor 13 , with a mirror being mounted on the opposite part ( 16 or 15 ), such that the system again operates as a barrier.
[0060] According to another variant, the passage of the yarn F is intercepted not as the interruption of a light beam but as the sliding of the yarn. This solution has the great advantage of verifying yarn passage not within a single point (crossing of the barrier light beam), but within an angular sector centred on the receiver element. This enables the passage condition to be intercepted with greater safety as it derives not from an instantaneous condition but from a condition of greater duration in terms of time. This makes the sensor much more robust and able to read any type of yarn with precision, in particular even very thin yarns.
[0061] As an alternative to that described, the barriers or the generated light beams could be partially superimposed in pairs, such as to have for each sensitive element two signals CHA and CHB and hence obtain the passage and direction data from the state of the transition CHA→CHB or vice versa (unwind, wind→LOAD, UNLOAD). In this manner the sensor 13 operates as an optical encoder.
[0062] FIGS. 6 and 7 , in which parts corresponding to those of the already described figures are indicated by the same reference numerals, show a further variant of the invention. According to this latter, the transmitters and the corresponding receivers are located on the second part 16 of the sensor 13 , the first part 15 not having been eliminated.
[0063] The second part 16 surrounds the member 5 even though distant therefrom (lower, in FIG. 6 ). This second part contains the emitters 18 and receivers 30 .
[0064] The operation of the device shown in FIGS. 6 and 7 is evidently the same as that shown in the already described figures.
[0065] Finally, if the feed device is formed as a fixed drum solution and hence the hollow shaft (which passes through it) is used for yarn passage, the hollow shaft transports the electrical signals for controlling the optical sensor.
[0066] These embodiments are also to be considered as falling within the scope of the invention as defined by the following claims.
|
A storage feed device for a yarn which unwinds from a corresponding bobbin and is fed to a textile machine. The device includes a rotary or fixed drum and an optical sensor member arranged to sense the movement of the yarn towards the textile machine. The optical sensor includes a plurality of emitters and receivers between which a light beam is generated and is interrupted by the yarn during its movement. The optical sensor includes a first fixed part and a second fixed part which includes the emitter and receiver elements, the first part being coaxial with the rotary member, the second being annular and surrounding the first part, the yarn moving between the parts.
| 3
|
BACKGROUND OF THE INVENTION
The invention relates generally to measuring devices, and more particularly a highly accurate device for mechanically locating a point which is at a desired fraction of the distance between two other points. It has many applications, such as in the construction industry, the drafting art, and around the home. Only two of several possible embodiments are needed to provide for a useful range of desired fractions.
Heretofore, when attempting to accurately measure half or one-third of the distance between two points it has been necessary first to measure the distance between the points, second to calculate the length of the desired fraction, and third to measure and mark that distance. Sometimes a caliper or micrometer has been used in conjunction with such measurements and calculators. In addition to being time consuming, a certain degree of error usually is inherent in such manual operations.
Another method of measuring desired fractions has been to traverse the distance with, for example, a rope, then fold the rope into halves or thirds, lay it along the original line and mark the desired point where the end of the fold falls. The inherent inaccuracy and time consumption of such a process is obvious.
The prior art does not provide an easily used, highly accurate device for locating the midpoint or one-third point of a desired distance. Devices such as rulers, calipers, micrometers, and measuring lines require a manual interaction, some calculation and probable inaccuracy. Remotely related solutions are found in the drapery art and in the hyperbolic position locator art.
Certain devices, as illustrated by U.S. Patents to Goudsmit, U.S. Pat. No. 2,562,664, and Johnson et al., U.S. Pat. No. 2,591,074, employ strings and pulleys to determine location as a function of the time it takes a radio signal to travel from a transmitting vessel to several receiving stations. The indicators are attached to moveable arms in a common plane, representing the receiving station, and are designed to vary distance in a hyperbolic function so that the intersection of the plotted lines indicates the position of the transmitter.
A more closely related technology is shown in Yaworsky and Morantz (U.S. Pat. Nos. 2,998,659 and 3,541,692) which teach the design of pleater gauges. These are used to determine where to put the pleats in a drapery composed of a number of pieces of material to be sewn together. The devices entail a series of indicator elements attached to each other and to a lead element by a series of lines. In Yaworsky different sized pulleys are used to provide for simultaneous differential expansion. By setting the complex mechanism of the gauge for the total width to be covered and for the number of pieces of materials being combined, the markers would be drawn out symetrically across the material showing where the pleats are to be located. Such devices are far more complex and serve a different function than the device of the present invention. Moreover, none of them teaches the novel arrangement of indicators and cord paths of the invention.
None of the prior art teaches a simple, compact and easy-to-use device for mechanically determining halves, thirds, and related fractions with a high degree of accuracy.
It is therefore an object of the invention to provide a device for readily indicating the location of a desired fraction of a total distance with a high degree of accuracy.
Another aspect of the invention provides a point locator device having a leading and a trailing indicator connected by a single line which passes over a number of pulleys so that the trailing indicator will be accurately drawn a desired fraction of the distance which the leading indicator is drawn, in the same direction.
A further aspect of the invention is the provision of a device which may be used with a high degree of accuracy and which retains that accuracy despite continued use, being resistant to forces applied to the indicators which would tend to alter this mechanical relationship between the indicators.
SUMMARY OF THE INVENTION
The invention teaches a mechanical point locator and distance divider for locating a second distance which is a fixed integral fraction of a first distance. The device has a base having a starting and a finishing end. There are two indicators, a leading indicator and a trailing indicator. Both indicators are slidably mounted for movement along the length of the base. The leading indicator is disposed closer to the finishing end than the trailing indicator. The trailing indicator is provided with pulley means, and pulley means are also provided on the base, at its starting end and at its finishing end. Cord means is provided for moving the trailing indicator a fixed integral fraction of the distance moved by the leading indicator, in the same direction of movement as the leading indicator. The cord means is fixed to the leading indicator and passes around the trailing indicator pulley means, and is associated with the trailing indicator and the finishing end of the base in a manner such that it forms an integral number of generally parallel runs, the integral number being the reciprocal of the integral fraction of movement. Return means is provided for returning the trailing indicator toward the starting end, with the movement relationship maintained, as the leading indicator is moved back toward the starting end. The return means can be a spring or a second cord means which passes from a trailing indicator pulley about pulley means at the ends of the base to the leading indicator. The second cord means is arranged to form the same integral number of generally parallel runs between the starting end and the trailing indicator. The invention includes embodiment wherein the integral fraction is one-half and one-third, and also smaller fraction.
DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the drawings of which:
FIG. 1 is a frontal schematic view of a halves-locating embodiment of the invention, with the indicators at the zero position;
FIG. 2 is a frontal schematic view of a thirds locating embodiment of the invention, with the indicators in a measuring position;
FIG. 3 is a sectional view of the device of FIG. 1 or 2, showing one manner in which the indicator may be slidably attached to the housing;
FIG. 4 is another sectional view, showing another manner of slidable attachment of the indicator to the housing;
FIG. 5 is another view in cross-section, showing a further arrangement for slidable mounting of the indicator to the housing;
FIG. 6 is a frontal view of another embodiment of the halves locator in which the zero point is not at an edge of the device;
FIG. 7 is a perspective exterior view of a point locating device according to the invention;
FIG. 8 is a frontal view of a halves-locating embodiment, showing an alternate and simplified cord arrangement;
FIG. 9 is a frontal view of a thirds-locating embodiment, showing an alternate cord arrangement; and
FIG. 10 is a view in cross-section, showing a trailing indicator with pulleys attached.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1, 2, 5 and 6, the mechanical point locator 10 is a device which may resemble an elongated rectangular box. Extending from the device are a pair of indicators or markers 14 and 16 which are slidably mounted on the device to enable them to be drawn along its length. The indicators are of two types, a leading indicator 14 to be drawn across the distance to be measured and a trailing indicator 16 to be conveyed across a distance which is a desired fraction of the distance being measured.
The indicators 14 and 16 are each connected through slot-like openings in one of the side walls of the device to a common cord or line 20 which is located inside the device. The openings 18 and the internal components are indicated schematically in FIGS. 1 and 2, as well as in FIGS. 6, 8 and 9, with the openings 18 and the internal components superimposed for clarity. The cord 20, in addition to being attached to the indicator, has two fixed end points within the device and passes over a series of turning points or pulley means which may comprise pulleys as shown or merely non-rotatable, low-friction direction reversing elements. As used herein, the terms "pulley" and "pulley means" can be taken to mean an actual pulley or a post or pin direction reversing element. The path of the cord 20 over the pulleys, and its attachment to the indicators 14 and 16, is done in a manner so that the motion of the leading indicator 14 along the length of the device will result in a simultaneous corresponding movement by the trailing indicator 16 in the same direction, but at a desired fraction of the speed and distance of the leading indicator 14.
Therefore, when the leading indicator 14 is at the zero point 26, the trailing indicator 16 will also be there, as shown in FIGS. 1 and 6. When the leading indicator 14 is moved twelve inches from the zero point 26, the trailing indicator 16 will have moved six inches in the half-point locator embodiments of FIGS. 1, 6 and 7, whereas with the thirds-locating embodiment the trailing indicator would have moved only four inches, as shown in FIG. 2. Multiple uses of the half-locator would sequentially indicate 1/2, 1/4, 1/16, 1/32, etc. of the original distance. Likewise, multiple uses of the thirds-locator would sequentially indicate 1/3, 1/9, 1/27, etc. of the original distance. Combined use of the two embodiments would indicate 1/6, 1/12, 1/18, 1/24, etc. A wide range of fractions is therefore obtainable through multiple uses of a half and a thirds locator. However, it is also within the scope of the invention to provide a single point locator capable of dividing a distance into any integral fraction, i.e., 1/n, where n is an integer, simply by providing additional pulley means and runs of cord beyond what is shown and described herein for half-point and third-point locators.
Reference to FIGS. 3, 4 and 5 shows that the mechanical point locator 10 preferably includes a housing 30 acting as a base and encasing the cord 20 and turning points 24. The back of the device is preferably flat with no protruding parts so that it may be set against the object to be divided, leaving the indicators freely movable. The hollow interior 32 of the housing, as surrounded by a front wall 34, back wall 36, top wall 38, and bottom wall 40 provides a sheltered space for the cord 20 and pulleys or turning points 24, preventing dirt and other objects from entering the device and jamming or otherwise interfering with operation of the device. Tracks 42 in the front wall 34 mount and guide the slidable indicators with little friction, preferably as shown.
It should be understood that the point locating devices of the invention do not depend for their operation on the housing 30, it being sufficient that some form of base is provided as a mounting for the cord 20, the pulleys or pulley means, and the indicators. Thus, a flat plate similar to the illustrated front wall 34, with appropriate indicator tracks and cord and pulley mountings could act as a base, with the indicators 14 and 16 extending straight up from their point of attachment at the track 42, as shown in dashed lines in FIG. 5. It is preferable that the mechanical workings of the device be fully housed as illustrated, to provide a smooth, flat surface for placement against the object being measured and to prevent any interferences with operation. Thus, although various modifications of the indicator, cord and pulley mounting arrangement shown in the drawings are considered to be within the scope of the invention so long as they employ the novel indicator and cord path relationships of the invention, they may be less desirable than the housing enclosed device.
Several arrangements are possible for slidably attaching the indicators 14 and 16 to the device. FIG. 3 illustrates one manner of attachment in which the indicator 14 or 16 is extended over the top wall 38 so that it lies flush with the back wall 36 against which the object would be placed. The indicator extends through the track 42 via bar means 46 which securely fits into the track 42. The bar means 46 may be a block of the material of which the device is made. Securing means 48, wider than the track, is attached to the internal side of the bar means 46 holding the indicator securely in place within the track 42. In one embodiment, shown in FIG. 5, the securing means 34 is a pair of pulleys 24, only one being shown, having diameters wider than the track 42. These pulleys 24 are rotatably attached to the inner side of the bar means 46, and in addition to holding the indicator from being pulled out of the track 42, form part of the mechanism for simultaneously moving the indicators in the desired ratio.
FIG. 4 shows a preferable manner of attachment of the indicators, employing tracks 50 indented into the top wall 38 and bottom wall 40 into which reciprocal tabs 52 securely fit for slidable attachment of the indicators. Connection through the front wall 34 to the cord 20 may be achieved by a post 54 or other suitable connection extending through a slot 18 and connected directly to the cord 20 for the leading indicator 14, or around posts extending from the trailing indicator 16 and supporting a pair of pulleys (not shown).
Regarding the materials of construction, the device itself may be made of wood, metal, plexiglass or other plastic, or other suitable material. Preferably a strong, durable plastic is employed. The cord or line 20 should be highly resistant to stretching forces to retain secure attachment within the device and to assure accuracy and avoidance of error. The pulleys 24 may be of any suitable material, rotatably mounted inside the device to eliminate wear on the cord from the path direction changes incurred during measuring. Of course, the device will function if low-friction posts are used to effect such direction change, but the illustrated pulleys are preferred because they assure smooth operation.
FIG. 6 shows an embodiment of a half-point locator wherein the indicators are slidably attached in the manner shown in FIG. 4, but wherein the zero point 26 is not at the end of the device. With the zero point 26 marked, etched or otherwise located on the housing 30, the indicators coincide therewith when in the zero position as shown in FIG. 6, and the zero point is always available as a reference during point locating. This point, rather than the end of the housing or base 30, is thus used to place alongside the measurement point on the object to which the point locating device is applied. Otherwise, this device is similar to that of FIG. 1.
A device with three indicators which simultaneously indicates halves and thirds is also possible by superimposing one cord path over the other in a single device, overlapping the trailing indicators so they both begin at the zero point, and having both cords attached to a single leading indicator 14 (not illustrated).
FIG. 7 shows in perspective a mechanical point locator 10 of the invention, as it preferably appears at the exterior. The embodiment of FIG. 7 employs a zero point 26c which is marked on the top wall 38 and the front wall 34 of the housing or base 30c, positioned inwardly from the left end 56 (as viewed in the figure) of the housing. A preferred single slot 42a for both indicators is shown, with a structural arrangement similar to that discussed above in reference to FIG. 4 for slidable retention of the indicators on the housing. As seen in FIGS. 7 and 4, an upper grooved track 50 is formed in the housing 30c, and a similar grooved track is on the bottom edge of the housing. The leading and trailing indicators 14c and 16c (FIG. 7) are generally U-shaped with track guides 52 (FIG. 4) extending from transverse flanges 45 of the U-shaped indicators into the tracks.
A very important feature of the invention is the arrangement of cord paths and pulley means shown in the drawings, which is effective to cause simultaneous movement of two indicators (or even three, as discussed above), in the same direction at different speeds and distances. By this arrangement, movement of the leading indicator causes the trailing indicator accurately to travel a fixed integral fraction of the distance travelled by the lead indicator.
The basics of the cord-pulley-indicator relationship for a half-point locator 99 are shown in the somewhat schematic view of FIG. 8. The two indicators 14 and 16 are slidably mounted to the base plate or housing 30a in a suitable manner, which may be as described above. In the device as illustrated, the beginning or starting end 56 of the base does not coincide with the zero point 26, the latter being spaced inwardly as shown. Near a finishing end 58 of the device a cord 20a is fixedly attached to the base at a point 100. This cord 20a passes over a pulley or pulley means 101 on the trailing indicator 16, changing direction, thence to a point 102 of fixed attachment to the leading indicator 14, forming two parallel runs of cord 20a. Thus, by arrangement described so far, movement of the leading indicator 14 to the right in the drawing will cause the trailing indicator 16 to move in the same direction at half the speed and distance. However, restraint is needed for preventing overtravel of the trailing indicator 16 and to return the trailing indicator back toward the starting end 56 when the leading indicator is so returned, according to the same speed and distance relationship. A simple spring or other tensioning device 103, shown in dashed lines in FIG. 8 may be provided for this purpose, connected to the base 30a and to the trailing indicator. However, it is preferable that a further cord arrangement be provided, acting oppositely, in a sense, to the cord 20a by pulling the trailing indicator back toward the starting end as the leading indicator is moved in that direction, the cord 20a is fed back toward its original position by the pulling movement of the trailing indicator 16.
Therefore, a second cord 20b extends from a fixed attachment point 104 near the starting end of the base 30a over a pulley means 106 on the trailing indicator, reversing direction, forming two parallel runs of cord 20b similar to the two runs of cord 20a. Movement of the lower run of cord 20b (as viewed in FIG. 8) will move the trailing indicator at half the speed and for half the distance. This lower run of cord 20b, as it leaves the pulley means 106, moves at the same speed and in the same direction as the leading indicator 14. To correlate these two similar motions, the cord 20b passes over two direction-reversing pulleys or pulley means 110 and 112, to a point of attachment 114 to the leading indicator 14 as illustrated.
The cords 20a and 20b may comprise a single cord 20, secured to the leading indicator with the illustrated attachment points 102 and 114 coinciding, and this is preferred, since the points 102 and 114 should be at the same level on the indicator 14 in any event to avoid any tendency of the indicator to be tilted in the track. Also, this requires only one attachment and provides a more efficient assembly.
FIG. 9 is a schematic view similar to FIG. 8, but showing the mechanical arrangement and function of a thirds locator 120. In this form of locator a first cord or cord portion 20c is connected to the trailing indicator 16 at a point 121, then passes over a direction-reversing pulley or pulley means 122 secured to the base 30b near the finishing end 58, then returns to the trailing indicator and passes over a pulley means 123 mounted thereon, thence to a connection 124 to the leading indicator. Thus, three parallel runs of cord 20c are formed, and movement of the leading indicator 14 to the right as viewed in FIG. 9 moves the three runs at successively different speeds and causes the trailing indicator 16 to move at one-third the speed and distance of the leading indicator. The remaining cord 20d in FIG. 9 provides for restraint and return of the trailing indicator, as in the half-point locator described above. As in that embodiment, a return spring (not shown) could be provided in lieu of the cord portion 20d, but the cord is preferred. As illustrated, the cord portion 20d acts similarly to the cord 20b, except that it provides for three initial runs of cord, from an initial connection point 126 on the trailing indicator over a base-mounted pulley means 127, then over a pulley means 128 on the trailing indicator and back toward the left in the figure to form the three parallel runs movable at different speeds. Further base-mounted pulley means 129 and 130 bring the highest-speed motion of the cord 20d to the leading indicator in precisely the same manner as in FIG. 8, the cord 20d being affixed to the leading indicator at a point 131.
In both embodiments described above it is important that all runs of cord connected directly to an indicator or to a pulley means on an indicator be parallel to the path of movement of the indicators, so that cord takeup and payout is balanced and stress and slack in the cord(s) are avoided. Of course, cord runs merely extending between base-mounted pulleys may be oblique if desired, since this will not affect operation. This is true of the devices of FIGS. 1-7 as well as FIGS. 8 and 9.
FIG. 1 illustrates one cord-pulley-indicator arrangement and other features for the half-point locator 10. The leading indicator 14 has a single fixed point of attachment 60 to the cord 20. The trailing indicator 16 has two rotatable pulley or pin points of connection to the cord 20, a return pulley means 62 shown at the left, and a forward pulley means 64 shown at the right.
The cord 20 begins at a fixed end point 22 at the beginning end 56 of the base or housing 30, passes around the return pulley means 62 on the trailing indicator 16, around a pulley 67 mounted on the beginning end 56, across the device and around a pulley 68 at the indicator or finishing end 58, back across the device to the leading indicator attachment 60. From here, a different cord may be used if desired, but as discussed above, preferably the same cord 20 extends (left in the figure) to another base-mounted pulley 69 at the beginning end 56, near the bottom, from which it crosses the device to a further base-mounted pulley 70 which may be at the same level as the pulley 69, at the indicating end 58. From here, the cord 20 goes up to an upper base-mounted pulley 71 at the indicating end 58, around the forward pulley 64 on the trailing indicator 16 to a fixed end point 22 near the indicating or finishing end. This arrangement should be compared to FIG. 8, since it provides for similar function but with additional base-mounted pulleys so that the connection 60 of the cord to the leading indicator can be at a preferred location. When the leading indicator 14 is drawn toward the right or indicating end 58, the cord will be drawn around the forward pulley 64 on the trailing indicator 16 causing it to travel in the same direction as the leading indicator but at a mechanical advantage of 1:2, as in the simplified device illustrated in FIG. 8. When the leading indicator 14 is moved back toward the beginning end 56, the cord will be drawn around the pulleys 68 and 67, then around the return pulley 62 on the trailing indicator, causing it to return in the same direction as the leading indicator, eventually to the zero point 26.
FIG. 2 illustrates an embodiment of a thirds locator. For simplicity, each pulley is shown separately, on a separate axis, but in some cases it may be preferable to have certain pulleys mounted coaxially, though still with independent operation. Such an arrangement is indicated somewhat schematically in FIG. 10 for two coaxial pulleys 72, and the arrangement may be used in any of these described embodiments. The same is true, of course if low-friction posts are used as direction reversing elements.
The cord 20 in FIG. 2 begins at a fixed end point 73 on the trailing indicator 16, from which it passes around a base-mounted pulley 75 at the beginning end 56, back around another base-mounted pulley 75 at the beginning end 56 and down around a further base-mounted pulley 76 at the beginning end 56. The pulley 76 is optional, but it helps avoid interference of the cord 20 with the return pulley 62. The cord then passes to a base-mounted pulley 77 at the indicating end 58, reversing direction and extending back to the fixed leading indicator attachment point 60. From here, the cord 20 (or a separate cord as described above) extends to a base-mounted pulley 78 at the beginning end 56, across to a similar pulley 79 at the indicating end 58 and up to an upper base-mounted pulley 81, around the forward pulley 64 on the trailing indicator 16 and around another base-mounted pulley 82 at the indicating end 58 to a point of fixed attachment 83 on the trailing indicator 16. The cord attachment points 83 and 73 could advantageously be at the pulley means 64 and 62 if the pulley means are simple low-friction direction reversed posts (not illustrated).
The attachment 60 to the leading indicator 14 should be made such that both indicators 14 and 16 are at the zero point 26 at the same time. As FIGS. 1 and 2 show, the points of attachment to the cord 20 are to the right of the indicator points 84 and 86, and the indicators are offset so the cross-over area 87 of the leading indicator 14 is above the cross over area 87 of the trailing indicator. The cross-over area 87 is, of course, eliminated in the embodiment shown in FIG. 6, where the zero point 26 is located to the right of the beginning edge 56.
To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosure and the description herein are purely illustrative and are not intended to be in any sense limiting.
|
A mechanical point locator and distance divider provides for quick and reliable division of a distance into an integral fraction of the distance, being useful for drafting, with maps or charts, in the construction industry and around the home. Leading and trailing indicators are slidably mounted on a base or housing, and a cord and pulleys appropriately interconnect them to cause the trailing indicator to move at a speed and for a distance which are an integral fraction of the speed and distance the leading indicator is moved by the operator. Provision is made for assuring the return of the trailing indicator according to the same desired relationship with respect to the return of the leading indicator. Half-point and third-point locators are specifically described, but the principles of the invention enable the provision of any fractional point locator wherein the distance desired to be located is an integral fraction of a distance to which the device is applied.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of co-pending U.S. application Ser. No. 10/244,376, filed on Sep. 16, 2002, which is a continuation of U.S. application Ser. No. 09/888,194, filed on Jun. 23, 2001, and now U.S. Pat. No. 6,450,477, issuing Sep. 17, 2002, which is a continuation of U.S. application Ser. No. 09/538,881, filed on Mar. 30, 2000, and now U.S. Pat. No. 6,250,605, issuing Jun. 26, 2001, which is a continuation of U.S. application Ser. No. 08/968,904, filed on Nov. 6, 1997, and now U.S. Pat. No. 6,089,531, issuing Jul. 18, 2000, which is a continuation of U.S. application Ser. No. 08/206,424, filed on Mar. 4, 1994, and now abandoned. Each of the above applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to an actuator apparatus and method and, more particularly, to a valve actuator including a bonnet assembly having an improved downstop mechanism that is rotatably free with respect to a floating top shaft and engageable with respect to a replaceable operator without affecting bonnet stem drift adjustment.
[0004] 2. Description of the Related Art
[0005] Gate valves are generally comprised of a valve body having a central axis aligned with inlet and outlet passages, and a space between the inlet and outlet passages in which a slide, or gate, may be moved perpendicular to the central axis to open and close the valve. In the closed position, the gate surfaces typically seal against sealing rings which surround the fluid passage through the valve body. Gate valves have been used for centuries to control the flow of a great variety of fluids. Often the fluid to be controlled by the gate valve is under pressure. In the petroleum industry, gate valves are used along piping at various locations, and in particular are used in piping referred to in the petroleum industry as a Christmas tree, which is used as part of a drilling operation.
[0006] Actuators to open and close the gate valves may include manual operators, diaphragm-type operators, and hydraulic operators. The actuator may include a bonnet assembly, which interconnects the valve body and the valve gate, and a bonnet stem which is movable with the gate via an operator. It is often desirable to be able to change the operator without changing the bonnet assembly. However, this is difficult because, among other reasons, such a change also requires changes in up-stop and down-stop adjustments which assure the drift of the gate is positioned correctly in the open and closed position. If the valve is connected to a Christmas tree or is under pressure, it may be difficult to determine whether drift adjustments have been made correctly when replacing the operator since the bore of the valve is not available to receive a drift alignment check tool. Removal of a valve under pressure in a Christmas tree to make drift adjustments may take considerable time and cause substantial inconvenience.
[0007] It is desirable to combine a manual operator with a diaphragm-type or hydraulic operator for back-up and test purposes. This combination typically results in the presence of a top shaft extending from the operator that may also serve to indicate whether the valve is open or closed. Because the top shaft is often exposed to the atmosphere, it may attract contaminants that cause damage to the top shaft seals or bearings. In the past, close tolerances have been required in the top shaft that have exacerbated the contaminant problems. As well, torque applied to the top shaft, which may be caused by manual operation, may cause gate, gate seal, or drift misalignment. Furthermore, changing the top shaft or the top shaft seals has previously required removal of the operator housing.
[0008] The operator typically has a maximum force capability for applying to the bonnet stem. It is sometimes desirable to provide additional opening/closing power on a temporary basis without having to remove the original operator. It is also desirable that the same operator be adaptable to various control accessories, such as a mechanical override, hydraulic override, heat sensitive lock open device, block open cap, electrical limit switch and/or other electrical accessories.
[0009] Another significant problem, especially related to diaphragm-type operators, is leakage of the diaphragms in the region adjacent the top shaft or bonnet stem. Such leakage may be caused by wear, loss of flexibility, and pinching or wear that occurs should the diaphragm make contact with the diaphragm case. This leakage may gradually develop, and may slowly reduce the operator power.
[0010] In some cases, the positioning of the gate valves in the Christmas tree and other types of installations may be restricted because of piping which is supplied to operate an automatic actuator that controls gate movement. In the past, it has been difficult to use precisely laid piping because the position of the operator fluid port is fixed with respect to the operator housing. Allowing the operator to rotate with respect to the bonnet could result in leakage or cause misalignment of the up-stop and downstop drift adjustments of the valve gate.
[0011] Thus, there has been a long felt need in the industry to provide an improved actuator that allows a more adaptable installation configuration, that reduces maintenance and installation time, and that increases long term durability. Persons skilled in the art will appreciate the present invention which provides solutions to these and other problems associated with valve actuators.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a valve actuator for moving a valve between open and closed states within a valve body. The valve actuator comprises an operator housing including a pressure chamber and a fluid port, and an operator member movable in response to the introduction of fluid into the pressure chamber through the fluid port. A bonnet housing is securable to the valve body and has a bonnet housing bore therethrough. A bonnet stem axially moves in the bonnet housing bore and is securable to the valve gate for moving the valve gate to the open and closed valve states. The bonnet stem is axially movable in response to movement of the operator member in an axial direction toward the valve body. The bonnet stem is rotatably free with respect to a top shaft.
[0013] A downstop member rotatably and axially affixed to the bonnet stem is used for stopping axial movement of the bonnet stem in a direction toward the valve. The downstop is also rotatably free with respect to the top shaft. A stop surface is fixably positioned with respect to the bonnet housing. One or more bonnet stem spacers are disposed on the stop surface and engageable by the downstop to stop axial movement of the bonnet stem for selecting a desired bonnet stem drift.
[0014] An object of the present invention is an valve actuator with improved versatility, reduced installation and maintenance, and/or increased life.
[0015] Another object of the present invention is an actuator which allows removal or exchange of the valve operator while the valve is under pressure.
[0016] Another object of the present invention is an actuator which allows removal or exchange of the valve operator without the need to reset drift adjustments or to examine the valve bore to determine if drift adjustments are correct.
[0017] A feature of the present invention is a floating top stem which requires no metal-to-metal contact during operation.
[0018] A further feature of a preferred embodiment of the present invention is an improved diaphragm having a metal insert ring to engage an elastomeric seal and thereby minimize or avoid in the diaphragm which may be caused by decreased diaphragm flexibility, leakage pinching or other reasons.
[0019] Yet another feature of present invention is a replaceable seal cartridge that allows renewal of top stem seals without removing the operator.
[0020] An advantage of the present invention is an economical construction for a valve actuator that is relatively simple yet reliable in construction, and is easy to service.
[0021] These and other objects, features, and advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an elevational view, partially in section, of a diaphragm-type valve actuator in accord with the present invention;
[0023] FIG. 1A is an elevational view, partially in section, of a block open cap attachable to the valve actuator of FIG. 1 ;
[0024] FIG. 2 is an elevational view, partially in section, of a bonnet assembly in accord with the present invention;
[0025] FIG. 3 is an elevational view, partially in section, of the bonnet assembly of FIG. 2 including drift adjustment lengths in accord with the present invention;
[0026] FIG. 4 is an elevational view, of a replaceable operator without readjustment of the down-stop or up-stop drift in a bonnet assembly in accord with the present invention;
[0027] FIG. 5 is a schematical representation of actuator accessory connections in accord with the present invention;
[0028] FIG. 6 is an elevational view, partially in section, of a dual actuator assembly in accord with the present invention; and
[0029] FIG. 7 is an elevational view, partially in section, of a hydraulic valve actuator in accord with the present invention.
[0030] While the present invention will be described in connection with presently preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents included within the spirit of the invention.
DETAILED DESCRIPTION
[0031] Referring now to the drawings, and more particularly to FIG. 1 , a diaphragm-type valve actuator 10 is shown in accord with the present invention. Top shaft 12 , which is preferably formed from stainless steel, effectively floats with respect to top diaphragm case 14 . As a general matter, all non-stainless metallic components in actuator 10 are preferably coated for protection against environmental conditions. Wear bearing 16 , as well as wear bearings 18 (shown in detail in FIG. 2 ), are preferably nonmetallic to eliminate close tolerance problems normally associated with the actuator top shaft and bonnet stem. The wear bearings effectively suspend top shaft 12 and bonnet stem 20 to thereby prevent metallic contact during operation. Thus, the wear bearings are preferably non-metallic and made from relatively hard plastic-like materials, such as Molygard, Nylatron, or Delrin. The wear bearings and other plastic-like components discussed hereinafter may also be made from various plastic-like materials such as, but not limited to, nylons, thermoplastics, resins, polyurethanes, phenolics, acetals, polyacrylates, epoxides, polycarbonates, polyester, aramids, polymers, molythane 90 , and fluorelastomers.
[0032] Top shaft 12 rotates independently of and is designed to eliminate transmission of torque to bonnet stem 20 , gate 22 , and/or gate seats (not shown) when using a manual override, such as manual override 24 shown in FIG. 5 . Top shaft 12 preferably is large enough in diameter to prevent bearing and buckling stresses when loaded by manual override 24 or hydraulic override 26 shown in FIG. 5 . (See also the dual actuator system of FIG. 6 and hydraulic actuator of FIG. 7 ). A large bottom shoulder 28 on top shaft 12 prevents top shaft 12 from being expelled from actuator 10 .
[0033] Top seal cartridge 30 can be removed for replacement as a single unit without disassembling top diaphragm housing 14 . Top seal cartridge 30 is preferably formed of a plastic-like material such as Delrin and is held in place by retainer ring 32 which is preferably stainless steel. Top seal cartridge 30 incorporates rod wiper 34 to keep the shaft sealing region therebelow clean of dirt, grease, and other contaminants for longer life of the seals. Rod wiper 34 is preferably made from Molythane 90 . Top seal cartridge 30 contains dual reciprocating stem seals 36 and dual static seals 38 to ensure seal integrity and long life. These and other seals may be T-seals or other substantially elastomeric seals, such as O-ring seals.
[0034] Diaphragm 40 is preferably formed of nitrile laminated with several layers of nylon to ensure strength and flexibility for years of service. Materials such as Viton, a fluoroelastomer, may be used for H.sub.2 S—CO.sub.2 applications. The layers of nylon in diaphragm 40 eliminate the need for lubrication and do not experience frictional wear. Diaphragm 40 includes stainless steel concentric insert seal ring 42 bonded thereto to act in conjunction with a static O-ring face seal 44 , which is provided in the diaphragm retaining nut 46 . This seal eliminates leakage in the stem area which may normally occur due to diaphragm aging, pinching, or reduced flexibility.
[0035] Diaphragm retaining nut 46 threadably engages diaphragm retainer plate 48 for easy, accurate installation. On up strokes of actuator 10 , diaphragm retaining nut 46 prevents any possible pinching of diaphragm 40 by stopping movement of bonnet stem 20 should diaphragm retaining nut 46 engage top plug 50 . Diaphragm retaining nut 46 provides dual stem seals 52 to engage and reliably seal top shaft 12 . Diaphragm retaining nut 46 is preferably formed of stainless steel.
[0036] Diaphragm retainer plate 48 engages downstop element 54 for downward axial movement of gate 22 via bonnet stem 20 when the cavity defined by top diaphragm housing 14 is filled with pressurized fluid, i.e. compressed air. Breather port 62 allows fluid (air) to flow out of lower diaphragm housing 64 as diaphragm retainer plate 48 moves downwardly. Downstop element 54 preferably is connected to bonnet stem 20 via large threads designed to withstand high load impacts and cycling for preventing changes in drift settings, as discussed hereinafter. Downstop element is also engaged by upper spring retainer 56 for upward movement of bonnet stem 20 induced by spring 58 and/or pressure within valve body 60 .
[0037] Top diaphragm housing 14 is sealingly secured to lower diaphragm housing 64 by bolts 66 and nuts 68 which secure diaphragm 40 therebetween. Diaphragm 40 is thus anchored by this connection and acts as a seal between the top diaphragm housing 14 and the lower diaphragm housing 64 . Base plate ring 70 is secured to lower diaphragm housing 64 by bolts 72 . Base plate ring 70 allows for 360 degree actuator rotation when exacting plumbing is required for connections to control pressure inlet 74 . Lower spring retainer 88 secures spring 58 into a centralized position. In FIG. 1A is shown lock open cap 76 which threadably engages top plug 50 and is secured to top shaft 12 with bolt 78 to secure the valve in the open position.
[0038] FIG. 2 discloses a portion of bonnet assembly 90 . Bonnet assembly 90 is shown complete with spring 58 in FIG. 4 . Preferably stainless steel stem spacers 92 are positioned on top of bonnet ring 94 . Stem spacers 92 are used to determine the downward stop drift by controlling the length of the stroke of bonnet stem 20 toward valve body 60 . Packing cartridge 96 acts in a similar manner as top seal cartridge 30 to seal between bonnet stem 20 and bonnet housing 98 . Packing cartridge 96 preferably is formed of stainless steel. Packing cartridge 96 contains O-ring seals 100 . Seals 102 are preferably T-seals comprised of Viton 90 rings with nylon backups. Packing cartridge 96 also includes rod wipers 104 to protect and maintain the long life of the sealing elements by preventing contaminants in the region of the sealing elements.
[0039] Bonnet stem threads 21 are designed so that no injury to the seals occurs when the stem is passed through packing cartridge 96 . Dual bearings 18 suspend bonnet stem 20 to preferably prevent contact of any metal surface thereby eliminating wear and galling to either the bonnet stem 20 or the packing cartridge 96 . To prevent rotation of bonnet ring 94 with respect to bonnet housing 98 , screw 106 is tightened into the corresponding groove or inset disposed adjacent the end portion of bonnet housing 98 . Rotation of bonnet ring 94 with respect to bonnet housing 98 may alter the stroke length adjustments as discussed hereinafter. Bonnet ring 94 retains packing cartridge 96 in position within bonnet housing 98 . Bonnet ring 94 also preferably includes an additional seal 102 for safety purposes.
[0040] To set the downward stroke length or drift 106 of bonnet stem 20 , stem spacers 92 are removed or added as necessary to increase or decrease the combined spacer width 108 as indicated in FIG. 3 . In setting the bonnet stem drift, downstop 54 is first tightened to bonnet stem 20 with drive nut 110 . Bonnet stem 20 is placed in its furthermost downward position. The position of the gate bore (not shown) through gate 22 is determined by running an appropriate drift tool (not shown) through valve body 60 . The number of stem spacers 92 may then be removed or added as necessary to provide an accurate drift setting.
[0041] Secondary metal-to-metal stem seal 112 provides sealing in the event of fire damage to the other seals and also acts as a stop for upward movement of gate 22 . The adjustment of the up-stop drift is made in a manner dependent upon valve manufacture designs but may typically involve threadably engaging the gate stem with the bonnet stem and rotating until the correct adjustment is reached. Further rotation may be prevented by such means as a pin or other retainer means.
[0042] FIG. 4 discloses the relative ease with which various operators 114 may be changed out without altering the up-stop and down-stop drift as discussed hereinbefore. Thus the operator may be exchanged with the valve under pressure. No additional drift adjustments are necessary because the alignment is not altered and remains accurate for the particular valve. This feature is especially useful where it may be difficult to make drift realignment. Base plate ring 70 may be rotated without changing the drift to accommodate the piping to inlet 74 .
[0043] FIG. 5 is a schematic disclosing numerous attachments that can be made to upper plug 50 and inlet valve 74 of actuator 10 . Upper plug 50 preferably includes a substantially large diameter threaded outer connection to avoid stresses when using accessories. Clear stem protector 116 protects top shaft 12 from adverse effects of weather, sandblasting, contaminating operating environments, and painting. Heat sensitive lock open device 118 mechanically holds open the actuator and valve when other safety systems are inoperative. This device locks the device in the down position allowing it to rise only in the event of fire. Mechanical override 24 is used to mechanically stroke the valve, and is preferably used on low pressure valves or during installation and testing. Electrical limit switch contact 20 permits remote indication of gate valve position. Various types of fusible plugs 122 , quick exhaust valves 124 , pneumatic relays 126 , and other sensors 128 may be used with inlet 74 and top stem 12 .
[0044] In the operation of diaphragm-type actuator 10 of the present invention, pressure is applied through fluid port 74 which moves both diaphragm 40 and diaphragm retainer plate 48 axially towards valve body 60 . This movement engages downstop 54 to move bonnet stem 22 downward (towards valve body 60 ) until downstop 54 contacts stem spacers 92 , whereupon further downward movement of bonnet stem 22 is prevented. At this point, gate 22 is properly aligned so that the valve is open (assuming a normally configured gate valve). If pressure is lost or purposely evacuated, the valve is closed via pressure from spring 58 acting against downstop 54 to move bonnet stem 22 axially away from valve body 60 until metal-to-metal contact is made at secondary stem seal 112 . This action is referred to as fail-closed operation. If required, the valve can be configured with a fail open gate design for vent or blow-down systems.
[0045] FIG. 6 discloses a dual actuator system which may be used to double the stroke power. Secondary operator 140 preferably threadably attaches to plug 143 via connector 141 . Lock down plug 154 prevents rotation of operator 140 with respect to operator 10 . Operation of secondary operator 140 is similar to that of single actuator 10 . Pressurized fluid enters fluid port 142 causing diaphragm plate 144 to move downwardly, thereby forcing stem adaptor 146 and top shaft 148 downwardly. Air is vented from vent hole 150 during the down stroke. Downstop 152 controls the down stroke drift in the manner discussed hereinbefore.
[0046] FIG. 7 discloses a hydraulic valve actuator 200 embodiment of the present invention. Top shaft 202 is kept clean via rod wiper 204 disposed within removable top plug 206 . Dual wear bearings 208 , preferably formed of molygard, are used to support top shaft 202 . Top plug 206 also includes a Polypak seal 210 , preferably formed of Nitroxile. Hydraulic pressure moves piston 212 axially downwardly to move downstop 214 into engagement with stem spacers 216 as described hereinbefore. Piston 212 floats on preferably non-metallic wear bearings 218 and is further sealed with seals 220 . Upper spring retainer 222 applies force from coil 224 to move downstop 214 upwardly. Base plate ring 226 is bolted to housing 228 and provides support for lower spring retainer 230 as described with respect to diaphragm-type actuator 10 .
[0047] The foregoing detailed disclosure and description of the invention is illustrative and explanatory thereof, and it will be appreciated by those skilled in the art, that various changes in the size, shape and materials as well as in the details of the illustrated construction, reliability configurations, or combinations of features of the various valve actuator elements of the present invention may be made without departing from the spirit of the invention.
|
A valve actuator apparatus and method comprises an operator housing secured to a bonnet assembly. The bonnet assembly is secured to the valve body, and includes a bonnet stem movably within a bonnet housing for moving a gate within the valve body to open and close the valve. A downstop member is fixably secured to the bonnet stem and engages removable stem spacers which are added or removed to obtain a selected bonnet stem drift setting. The operator housing connects to a base ring that surrounds the bonnet housing and rotates to allow positioning of a fluid port in the operator housing. The operator housing may removed and replaced without altering the bonnet stem drift adjustment. A top shaft extends from the operator housing and rotates with respect to the bonnet stem to prevent torque transmission from the top shaft to the bonnet stem. A replaceable sealing cartridge sealingly supports the top shaft for axial movement within the operator housing.
| 5
|
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/440,734, filed Jan. 17, 2003, and entitled “METHOD FOR USING A SYNCHRONOUS SAMPLING DESIGN IN A FIXED-RATE SAMPLING MODE”, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present application generally relates to apparatuses such as television signal processing apparatus, that process radio frequency signals. More specifically, the present application is particularly useful in integrated circuits that combine circuitry operating in a synchronous-sampling mode that must be adapted for use with a fixed rate sampling mode application.
BACKGROUND OF THE INVENTION
[0003] The present application generally relates to apparatuses such as television signal processing apparatus, that process radio frequency signals. More specifically, the present application is particularly useful in integrated circuits that must combine circuitry operating in a synchronous-sampling mode that must be adapted for use with a fixed rate sampling mode application.
[0004] Modern signal processing apparatus typically include signal processing circuitry for processing a multitude of signal formats, such as NTSC, ATSC, QAM, or satellite signals. Such a signal processing apparatus typically includes various components such as a tuner for selecting a particular signal or channel from a plurality of signals or channels received by the apparatus. To process digital signals, such as ATSC or satellite signals, the signal processing circuitry, and in particular the tuner, must perform these functions with high-speed digital circuitry. Some digital signal processing apparatus operate in a synchronous-sampling mode, where the A/D converter takes samples coincident with the digital symbol locations. The digital symbols, and subsequently the sampling frequency are calculated by the demodulator and a rate control signal is output from the demodulator to control the sampling rate of the A/D. It is also possible to take samples using an A/D converter at a fixed time intervals.
[0005] It is often a major design change in terms of time and expense to convert a design originally intended to operate in synchronous-sampling mode to operate in a fixed-rate sampling mode. This is primarily due to the requirement for an enable signal to be provided to all of the memory elements in the design. An enable signal is required throughout the design to identify when processing is to proceed since the demodulator is running at a high rate and not every clock signal is accompanied by a digital symbol. A thorough knowledge of the original design is usually required to effectuate the design change and re-verification is required to be carried out. In situations of design reuse, it would be advantageous to introduce a preprocessing block that can convert the fixed rate samples to synchronous samples with requiring the necessity of an enable line.
[0006] Furthermore, in digital signal processing applications, there are typically many different clocks used to drive the processing circuitry. These clocks are typically derived from a phase-locked loop (PLL). When the data is gathered through an A/D converter, using the PLL output to clock the A/D converter can degrade its performance as high speed A/D converters are sensitive to clock jitter. When an external clock is used to drive the A/D converter, a synchronization problem arises because of the unknown phase between the A/D clock and the PLL output clock. Previously, designers have used clock resynchronizers or back to back flip flops on the reference clock and PLL clock lines. This solution is based on the assumption that a “bad phase” occurs only some of the time. However, if the system starts up in the “bad phase” it will continue to operate constantly at the bad phase. This results in the data latching and putting the system into an unstable state. Therefore the robustness of the back-to-back flip flop approach is questionable. It is desirable to have an AND clock to be used by the digital signal processing circuitry that is synchronized to the PLL output clock to facilitate latching the AND output and preventing problems associated with clock jitter.
SUMMARY OF THE INVENTION
[0007] In accordance with an aspect of the present invention, a signal processing apparatus signal processing apparatus comprising a source of a fixed rate digital signal, a signal processor operating in a synchronous-sampling mode for producing a control signal representing a symbol rate, and an interpolator responsive to the control signal for processing the fixed rate digital signal to yield samples at the symbol rate.
BRIEF DESCRIPTION OF THE DRAWING
[0008] 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:
[0009] FIG. 1 is a block diagram of a television signal processing apparatus according to an exemplary embodiment of the present invention;
[0010] FIG. 2 a block diagram of an exemplary embodiment of digital signal processing circuitry utilizing an A/D converter operating according to a fixed rate sampling mode concurrently with subsequent signal processing circuitry operating according to a synchronous sampling mode;
[0011] FIG. 3 a block diagram of clock generator circuitry according to an exemplary embodiment of the present invention;
[0012] FIG. 4 is a diagram of a clock divider circuitry of a clock generator according to an exemplary embodiment of the present invention; and
[0013] FIG. 5 is a timing diagram of the clock divider circuitry according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The exemplifications set out herein illustrate preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
[0015] Referring to FIG. 1 , a block diagram of an exemplary embodiment of television signal processing apparatus 100 of FIG. 1 is shown. In FIG. 1 , television signal processing apparatus 100 comprises signal receiving means such as signal receiving element 110 , tuning means such as tuner 130 , demodulation means such as demodulator 140 , decoding means such as decoder 170 , processing means and memory means such as processor and memory 180 , audio amplification means such as audio amplifier 190 , audio output means such as speaker 135 , video processing means such as video processor 145 , and visual output means such as display 155 , a power supply 125 and a switch 115 responsive to the processor and memory 180 . Some of the foregoing elements may for example be embodied using integrated circuits (ICs). For clarity of description, certain conventional elements of television signal processing apparatus 100 including control signals may not be shown in FIG. 1 . According to an exemplary embodiment, television signal processing apparatus 100 may receive and process signals in analog and/or digital formats.
[0016] Signal receiving element 110 is operative to receive signals including audio, video and/or auxiliary data from signal sources, such as radio frequency broadcast signal transmission sources, or cable television transmission. Signal receiving element 110 may be embodied as any signal receiving element such as an antenna, input terminal or other element.
[0017] Tuner 130 is operative to tune signals including audio, video and/or auxiliary data signals. Accordingly, tuner 130 may tune signals for the main picture of television signal processing apparatus 100 . According to an exemplary embodiment, television signal processing apparatus 100 may further include a picture-in-picture (PIP) function wherein the first channel includes audio and/or video signals for a main picture, and a second channel (not shown) includes audio and/or video signals for the PIP function. Demodulator 140 is operative to demodulate signals provided from tuner 130 , and may demodulate signals in analog and/or digital transmission formats.
[0018] Decoder 170 is operative to decode signals including audio, video and/or auxiliary data signals provided from the demodulator 140 . According to an exemplary embodiment, decoder 170 decodes digital data that represents program guide data or emergency alert signals indicating an emergency event. Decoder 170 may also perform other decoding functions, such as decoding data which represents auxiliary data signals included in the vertical blanking interval (VBI) of an analog television signal.
[0019] Processor and memory 180 are operative to perform various processing, control, and data storage functions of television signal processing apparatus 100 . According to an exemplary embodiment, processor 180 is operative to process the audio and video signals provided from decoder 170 , and may for example perform analog processing, such as National Television Standards Committee (NTSC) signal processing and/or digital processing, such as Motion Picture Expert Group (MPEG) processing.
[0020] The processor and memory 180 is also operative to receive the auxiliary data signals from decoder 170 and determine what actions are required based on the auxiliary data received. For example, if EPG data is received, the processor 180 may decide to sort the EPG data and store the data in the processor's associated memory 180 . If the processor 180 receives auxiliary data associated with the emergency alert function of television signal processing apparatus 100 , it may compare data in the emergency alert signals to user setup data stored in memory 180 to determine whether the emergency alert function is activated to activate emergency alert signals.
[0021] Audio amplifier 190 is operative to amplify the audio signals provided from processor 180 . Speaker 135 is operative to aurally output the amplified audio signals provided from audio amplifier 190 .
[0022] Video processor 145 is operative to process the video signals provided from processor 180 . According to an exemplary embodiment, such video signals may include information based on the data contained in the received auxiliary data signals such as EPG information or emergency alert information. Video processor 145 may include closed caption circuitry that enables closed caption displays. Display 155 is operative to provide visual displays corresponding to processed signals provided from video processor 145 .
[0023] Referring to FIG. 2 , a block diagram of an exemplary embodiment of digital signal processing circuitry 200 comprising A/D converter 220 operating according to a fixed rate sampling mode concurrently with subsequent signal processing circuitry, such as a demodulator 240 , operating according to a synchronous sampling mode is shown. The digital signal processing circuitry further comprises a tuner 210 , interpolator 230 , clock generator 260 , and phase locked loop (PLL) 250 as well as a fixed rate clock 270 .
[0024] In this exemplary embodiment shown in FIG. 2 , the tuner 210 outputs an intermediate frequency (IF) analog signal. The A/D converter 220 takes samples of the IF analog signal at a fixed sampling rate. These fixed rate samples are taken at times corresponding to the digital clock signal input into the AND converter 220 by the fixed rate clock 270 . The fixed rate samples are read at the fixed rate by the interpolator 230 and a discrete number of samples are stored by the interpolator 230 , the number of samples depending on the interpolation method used by the interpolator 230 .
[0025] The interpolated samples are then interpolated to yield samples at the symbol rate or some integer multiple thereof in the Interpolator 230 based on the rate control signal from the demodulator 240 . In a synchronous sampling mode of operation, the rate control signal might have originally been used to control the frequency of a voltage controlled oscillator (VCXO). As such, the interpolator 230 is designed such that its rate control input has the effect of mimicking the effect of this rate control signal going to a VCXO on the data samples delivered to demodulator 240 . The interpolator 230 operates using the fixed rate clock 270 , whereas the demodulator 240 runs on a burst clock generated by the clock generator 260 . The burst clock is enabled by the interpolator 230 when there are samples in the interpolator 230 ready to be processed by the demodulator 240 . There may be more than one clock frequency generated by the clock generator 260 going to the demodulator 240 and subsequent synchronous sampling mode circuitry. All of these clocks are allowed to run for 1 symbol of time for every symbol extracted from the interpolator 230 . For example, a clock running at 8 times the symbol rate would be allowed to run for 8 periods for every symbol taken from the interpolator 230 .
[0026] Referring to FIG. 3 , a block diagram of clock generator circuitry 300 according to an exemplary embodiment of the present invention is shown. In FIG. 3 , the clock generator circuitry 300 comprises an AND converter 310 , a PLL 350 , a clock divider 360 , and a demodulator 340 . The clock divider 360 is used to synchronize the clock generated by the PLL and the reference clock, which is further explained in the discussion of FIG. 4 , as well as creating multiple integers of the synchronized clock signal to be used by subsequent signal processing circuitry.
[0027] Referring to FIG. 4 , a diagram of a clock divider circuitry 400 of a clock generator according to an exemplary embodiment of the present invention is shown. In FIG. 4 , the clock divider circuitry 400 comprises a plurality of D flip-flops 405 , 410 , 415 , 420 , 425 , 460 , 465 , 470 , a plurality of AND gates 430 , 435 , 440 , 445 , a plurality of OR fates 250 , 255 . In the exemplary embodiment of the present invention shown in FIG. 4 , five D flip-flops 405 , 410 , 415 , 420 , and 425 are used to create a delay line for the reference clock. The PLL clock is used to advance the state of the delay line. The group of logic elements comprising the AND gates 430 , 435 , 440 , 445 and the OR gates 450 , 455 are used as a means for comparing the various output stages of the delay line 405 , 410 , 415 , 420 , 425 . For example, to generate the 1× clock, the state of the outputs of the first D flip-flop 405 , the second D flip-flop 410 , the fourth D filp-flop 420 , and the fifth D flip-flop are compared using the group of logic elements 430 , 435 , 440 , 445 , 450 , 455 . The 1× clock is then passed through a final D flip-flop 460 to complete the synchronization of the reference clock with the PLL clock.
[0028] Referring to FIG. 5 , a timing diagram of the clock divider circuitry according to an exemplary embodiment of the present invention is shown. The timing diagram shown represents the signal state at indicated points on the clock divider circuitry of FIG. 4 400 .
[0029] 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.
|
The present application generally relates to apparatuses such as television signal processing apparatus that process radio frequency signals. More specifically, the present application is particularly useful in integrated circuits that must combine circuitry operating in a synchronous-sampling mode that must be adapted for use with a fixed rate sampling mode application. According to an exemplary embodiment, the television signal processing apparatus comprises a source of a fixed rate digital signal, signal processing circuitry operating in a synchronous-sampling mode wherein the signal processing circuitry comprises a signal representing a symbol rate, and an interpolator for processing the fixed rate digital signal to yield samples at the symbol rate.
| 7
|
BACKGROUND OF THE INVENTION
The instant invention relates to a disposable syringe with needle cover, of the type ready to be used; the needle and its corresponding protecting sheath as well as the remaining parts and forming elements being also ready to be used and being sterilized. The advantage of the syringe of the invention is that the user will have no contact with the needle or surrounding regions, before, during and after the injection; the assembly being completely disabled thereafter.
More particularly, the instant invention relates to a syringe of the above mentioned type comprised by a main cylindrical, hollow body, having a solid plunger displacing therein, which is located coaxially, the inner space of said cylindrical main body constituting the transient housing of the liquid or medicine to be injected, as well as of blood or other liquids to be withdrawn from the body, in accordance with the displacement direction of such plunger.
PRIOR ART
As already known, such main cylindrical body has a wholly opened base defining an opening from which the rear end of said coaxial plunger projects, such plunger being characterized by having an annular flange in order that the user may push or pull manually the plunger, according to the desired action. The inner end or head of the plunger tightly fits inside the walls and at the bottom of said main body, such that the variable volume chamber defined therein is always tight and isolated from the outside. Said bottom has, in turn, an outer frusto-conical hollow and coaxial nozzle converging towards its outer end, constituting the plugging means for coupling and fixing the injection needle.
This conical coupling means is standard in conventional syringes and is called "plugging cone" or "luer cone". To this end, needles which may be placed separately, housed inside a protecting sheath keeping them duly isolated and sterilized, have at their rear end the corresponding coupling means integral with the needle, such coupling means having its inner surface mating with said plug at the "luer cone", while the outer surface serves for removably coupling said sheath protecting the needle.
Considering the highly contagious diseases, specially those being transmitting through blood, the present approach is to attain disposable and disabled syringes, thus assuring whole sterility and reliance to patients. Several embodiments are already known in which the syringe and needle are disabled after their use.
Nevertheless, there is no embodiment protecting and assuring the impossibility of infection to the person applying the injection to the patient, specially taking into account that such person is that handling the syringe with the risk of an undesired puncture or of contacting small blood droplets from the patient when introducing or withdrawing the needle. When injecting with known syringes, the assembly is withdrawn pulling outward syringe and needle. In this way, accidental punctures may occur, thus causing leakages of blood or of the liquid injected on the patient's skin, on the hands the user, on clothes or other elements used for applying the injection, all of which may imply contamination.
SUMMARY OF THE INVENTION
The syringe of the instant invention offers an efficient solution to both problems. Its constructive features prevent the possibility of re-use and include simultaneously a shiftable needle cover avoiding all contact of the user with the needle. In fact, such needle cover is an end cylindrical body coaxially surrounding the main body, being shiftable longitudinally therealong, until it is located as axial projection of the syringe along a portion long enough such as to house the needle used, without any risk of dangerous leaks; further, handling of the syringe will be safe, avoiding accidental punctures, splits or other dangerous situations.
The invention also includes an insert between the syringe plugging cone and the needle plugging cone. This insert has two essential features influencing the general operation of the syringe: the first is that, being coupled to the upper end of the syringe, it provides the standard "luer cone" for coupling the needle and, the second one is that it has an outer annular flange engaged to inner lower retention means of the needle cover, such that, after the injection is effected, when the needle cover is withdrawn and disposed, this cover entraps the needle which is retained by such means. It is clear that the user may never contact the needle.
Further, the insert, as mentioned, is that having the "luer cone" and not the syringe. Therefore, the syringe is also disabled and cannot be used again since it does not longer have the proper plugging cone for receiving a conventional needle.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred, non-limiting, embodiment of the invention will be hereinbelow described in connection with the accompanying drawings, in which:
FIG. 1 is a longitudinal and axial section of a disposable syringe with needle cover, before being used, according to the instant invention;
FIG. 2 is a section similar to that of FIG. 1, showing the forming elements, with the needle already applied to the patient and the syringe plunger in a position for injecting the liquid product;
FIG. 3 is the same section, but indicating the way in which the needle cover acts during the withdrawal action of the syringe;
FIG. 4 is another longitudinal section, similar to former ones, indicating the way in which the two main portions of the syringe of the invention are separated and disabled.
In all figures, the same reference numerals designate the same or equivalent elements.
DETAILED DESCRIPTION OF THE INVENTION
As may be seen in all figures, the syringe is comprised by a main hollow cylindrical body 1, a plunger penetrating and displacing tightly through the open end of the body 1, thus defining a variable volume chamber 3, which is filled with the liquid or medicine to be injected to the patient, using the needle 4 to this end.
The novelty of the invention resides in the needle coupling along with the use of a needle cover.
In fact, said main body 1 has at its closed end, opposed to the mouth, a small conical nozzle 6 and an annular wall having a diverging inner surface 7 defining the pressure, removable seating means of a novel and particular insert 8, in which a plugging cone is located 9, whose dimensions are those established for the removable coupling of the needle through its integral joining means 10.
The conical nozzle 6, as well as the plugging cone 9, have an inner conduit axially communicating with the interior of the main body 1, wherein the liquid to be injected is contained.
The assembly also has an outer cylindrical needle cover 15 which is coaxial to the main body 1 and the plunger 2 which has a longer length and is shiftable with respect to said main body; having in turn two inner lower annular projections 12 and 13 constituting means for retaining the insert 8, as will be explained hereinbelow, as well as an upper inner annular flange 11 holding the insert in a stable position prior to use and, finally, a lower and outer annular lug 14 is provided in order that the user may displace the needle cover with respect to the main body, or vice-versa, i.e. displace the main body with respect to the needle cover.
The user, after removing sheath 15 protecting needle 4, introduces the needle into a patient P, as shown in FIG. 2, after which, bearing the front end of the needle cover on the patient's skin, the medicine is injected displacing plunger 2 in the direction F1.
With reference to FIG. 3, the novel protecting action of this embodiment may be seen. Through the use of the mentioned annular lug 14, the user retains the needle cover 10 on the patient's skin and displaces outwardly and simultaneously the needle 4 and the main body 1, which are engaged; this is carried out by a movement in the direction indicated at F2. In this step, the needle is integral to the main body through the action of said insert 8 engaging both elements as mentioned above and shown in the three first figures.
It is clear, from FIG. 3, that any undesired splash produced along with the removal of said needle is confined at the interior of the needle cover 16, preventing any possibility of contact with the user.
With reference to FIG. 4, the operation of the syringe of the invention at the last step of the injection may be understood. Maintaining the needle cover 16 on the patient's skin, the main body is displaced 1 in the direction indicated by F2, which produces withdrawal of said main body 1 with respect to the needle, since insert 8 offers a very low resistance to traction in this direction. Simultaneously, the same insert 8 is retained at the inner space of the needle cover the user having not contacted the needle. To this end, projections 12, 13 act along with an annular flange 17 of the novel insert 8.
Therefore, the disposable feature of the syringe of the invention may be understood by the use of the needle cover 16 along with insert 8 which, as mentioned above, forms a "luer" standard cone capable of retaining the needle 4 by plugging and, in turn, cone 9 has a special shape in its inner conical cavity allowing the removable coupling on said conical nozzle 6 of the main body.
Measures and proportions of conical nozzle 6 are not the conventional ones for retaining injection needles such that, said separated syringe portion may not be used again since it is impossible to place another needle thereon.
Regarding retention elements designated with reference numerals 11, 12, 13, 7 and 17, it is to be note that they correspond to a constructive embodiment chosen as example of the invention, but equivalent resources may be used for the same function.
It will also be noted that in FIGS. 1, 2 and 3, the lower portion of the needle cover, wherein retention means 12 and 13 are located, the needle cover body has a slightly diverging shape, since it has a compressive resilient tendency in order to cooperate with coupling and retention of insert 8; which, upon being withdrawn from the main body 1, confines its annular flange 17 between said means 12 and 13.
|
Disposable syringe with needle cover including a slidable needle cover preventing contact of the user with the needle and preventing re-use of the assembly.
| 0
|
PRIORITY DATA
This application is a continuation-in-part of U.S. Ser. No. 08/960,303 filed Oct. 29, 1997, now U.S. Pat. No. 5,945,116, which claimed the benefit of U.S. Provisional Application No. 60/030,307 filed Nov. 5, 1996.
TECHNICAL FIELD
The present invention generally relates to prophylactic and therapeutic agents for the prevention and treatment of viral-induced tumors, such as warts. In one embodiment, the therapeutic agent is in the form of a soap, comprising natural sandalwood oil and vegetable ingredients. More specifically, the therapeutic agent is sandalwood oil or an isolate or isolates from the sandalwood oil described herein. Use of the oil or its components as a topical agent for the prevention and treatment of viral-induced tumors, such as human papillomavirus-induced tumors, is disclosed.
BACKGROUND OF THE INVENTION
Viruses which induce tumors in mammals are widespread. Indeed, there are over sixty known types of human papillomaviruses (HPV) which are DNA viruses. These viruses can induce the production of tumors. Some of these HPV's have been associated with benign tumors, such as common warts, while others have been strongly implicated as etiologic agents in dysplasia and carcinomas in the oral and genital mucosa of the infected mammal.
Warts are a very common skin lesion in humans and are caused by various human papillomaviruses (DNA virus). Each virus is related to a specific clinical presentation of the wart. Warts are infectious and can be autoinoculated and spread to other individuals by direct contact.
Verrucae warts have a rough surface, are lumpy and typically flesh colored. Finger-like projections and sometimes dark specks are present, which are the result of thrombosed capillaries. Usually these warts are found on the face and scalp. Plantar warts are found on the planter surface of the feet and can be deep and painful. These warts occur singularly, in clusters or be spread over a wide area. Flat warts are typically small, flat-topped, flesh colored papules that occur primarily on the face, hands and forearms. Usually the surface of the wart is smooth and they may appear in the hundreds. Genital warts are soft, flesh colored or slightly pigmented and occur in the genitalia of the mammal and are sexually transmitted. Chronic infections of the viruses that cause genital warts in women are a serious problem as intra epithelial neoplasia or squamous cell carcinoma may develop. See Oski et al., Princ. Pract. Pediatrics, 2nd ed., pp. 789-790.
There are various therapies for the treatment of warts, but none are considered truly effective as they typically fail to totally cure the lesions and do not prevent recurrence. A discussion of presently accepted therapies can be found in Stone, 1995, Cl. Infec. Diseases, Suppl. 20, pp. 991-997 and Sterling, 1995, Practioner, Jan. 239(1546), pp. 44-47. Numerous compositions are presently marketed for wart removal. One such product is Occlusal®-HP marketed by the GenDerm Corporation of Lincolnshire, Ill. This product is a 17% solution of salicylic acid in a polyacrylic vehicle. The Shering-Plough Company of Memphis, Tenn. produces and markets a product known as Duo Film® which is a patch containing salicylic acid. The product literature recommends that the wart be washed and dried prior to the application of a medicated patch which contains 40% salicylic acid. This patch is then covered with an additional bandage and the procedure is repeated every 48 hours until the wart is gone, which sometimes takes up to 12 weeks.
Recently, it has also been observed that individuals with depressed immune systems, such as sufferers of Acquired Immune Deficiency Syndrome (AIDS), are prone to HPV infections which can result in tumor growth over their entire bodies, resulting in great mental and physical distress to the afflicted individual.
Current modalities for the treatment of viral-induced tumors involve the removal of the tumor by either: (1) surgical intervention (laser or operative); (2) the application of organic acids, such as glacial acetic acid and/or salicylic acid and lactic acid to "burn" the tumor away; (3) the injection into the tumor of an anti-tumor vaccine prepared from ground tumors; and to a lesser extent, (4) the use of a drug, such as podophyllin, interferons and fluorouracil or 5-FU; and (5) freezing.
While being useful for removing the viral-induced tumor, the current treatment modalities still suffer from one or more of the following drawbacks: (1) they can result in the destruction of healthy uninfected tissue; (2) they can result in scarring and disfigurement; (3) they can result in discomfort to the mammal being treated thereby; (4) they can result in necrosis of the tumor and the surrounding tissue may can result in a secondary infection which may require treatment with an antibiotic; and (5) they do not always result in the destruction of latent viral DNA which may be maintained in surrounding tissues. Furthermore with these conventional treatments, subjects suffer from significant local, and at times, systemic side effects, incomplete resolution and frequent recurrences of the tumors, and of course, the expense incurred.
It is also known that phototherapy is used for removing laryngeal papillomatosis tumors. While such phototherapy reduces tumor growth by about 50%, it also results in a generalized skin photosensitivity for at least six weeks, as well as other minor reactions. Despite the apparent success of this technique, the presence of latent viral DNA is nonetheless still maintained in the surrounding tissues.
U.S. Pat. No. 5,073,630 discloses a polymeric anhydride of magnesium and ammonium phospholinoleate with antiviral, antineoplastic and immunostimulant properties. This antiviral agent is produced from a selected line of Aspergillus sp. However, the compound is insoluble in water and possesses a high molecular weight (316,000 daltons). Recovery of the compound from the culture is problematic and costly.
U.S. Pat. No. 5,562,900 discloses a composition for the treatment of viral-induced tumors comprising an Aspergillus fermentation extract or a derivative thereof in a pharmaceutically acceptable carrier.
U.S. Pat. No. 5,541,058 discloses an in vitro method for testing the effectiveness of antiviral agents. More specifically, this patent relates to a method for screening anti-papillomavirus drugs which can interfere with the early and maintenance stages of papillomavirus infection. The teachings of this patent are incorporated herein by reference.
U.S. Pat. No. 5,332,215 discloses a method for inhibiting viral proliferation by preventing or inhibiting viral replication or killing the virus on contact. The method uses serine protease inhibitors, their analogs, salts, conjugates or derivatives.
An article by B. M. Lawrence entitled "Progress in Essential Oils", Perfumer & Flavorist, Vol. 16, 49-58 (1991) reviews the work of several investigators on the chemical composition of sandalwood oil. This article reports on several of the oxidation products of the oil and compares the composition of Chinese sandalwood oil and Indian sandalwood oil. The santalol content (santalol, cis-α and cis-β, comprises about 50 and 20% respectively by weight of sandalwood oil) of various species of the genus Santalum, are also disclosed. This article makes no suggestion that sandalwood oil would be effective in treating the common wart in humans.
An article by Dwivedi et al. entitled, "Chemopreventive effects of sandalwood oil on skin papillomas in mice" in the European Journal of Cancer Prevention 1997; 6(4): 399-401, reports that the essential oil, emulsion or paste of sandalwood (Santalum album L) has been used in India as an ayruvedic medicinal agent. In his investigation, a 5% w/v solution of sandalwood oil in acetone was shown to be a chemopreventive agent against 7, 12-dimethylbenz(a)anthracene initiated and 12-O-tetracecanoyl phorbol-13-acetate promoted skin papillomas in CD1 mice. The author suggests that sandalwood oil could be an effective chemopreventive agent against skin cancer.
None of these references suggest or disclose the use of sandalwood oil or a soap containing sandalwood oil as an agent for the treatment of human papillomavirus-induced tumors. There presently exists in the medical community a need for improved methods and compositions which provide prophylactic and/or therapeutic treatment of viral-induced tumors such as warts in humans. The present invention fills that need of the medical community.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to the use of at least one constituent of sandalwood oil or a soap containing sandalwood oil for the prevention and treatment of viral-induced tumors. Another aspect of the invention relate to the use of a component or components of said oil to prevent and treat viral-induced tumors in mammals, especially humans. One major benefit of the present invention is that that oil and soap do not destroy healthy, uninfected tissues nor results in either significant systemic side effects, local side effects such as irritation, necrosis of tissue surrounding the wart, allergic rashes, scarring, disfigurement or discomfort to the human treated therewith. In fact, the use of sandalwood oil or a soap containing the oil has been found to smooth the patient's skin and provide for regeneration of healthy tissue.
Another aspect of the present invention is directed to a simple method for providing prophylactic and therapeutic treatment of viral-induced tumors in humans. An additional aspect of the present invention relates to a method for the destruction of latent viral DNA which is contained in tissues so as to prevent recurrence of these tumors.
Thus, there is disclosed a method for the prevention and treatment of viral induced tumors and skin cancers in a mammal, said method comprising the topical application of sandalwood oil.
Also disclosed is a prophylactic and therapeutic composition for the prevention and treatment of viral induced tumors in mammals comprising sandalwood oil extract, or a derivative thereof, in a pharmaceutically accepted carrier and wherein said sandalwood oil extract is obtained from a Santalum species selected from S. album, S. yasi, S. papuanum, S. spicatum and mixtures thereof.
There is further disclosed a method for the prevention and treatment of genital warts, cancer of the cervix and eradication of human papillomavirus from the female genital tract in infected females, comprising the application of a cream or douche derived from at least one constituent of sandalwood oil to the affected area of the human body. There is also disclosed a method for preventing cancer of the cervix, said method comprising the application of sandalwood oil to the genital area of a female for a period of time and at a sufficient concentration to eradicate the human papillomavirus from the genital area of the female. There is also disclosed a method for the treatment and prevention of dry skin, flakiness of the skin, rashes associated with seborrheic dermatitis, psoriasis, eczematous and allergic rashes in a human, said method comprising the topical application of a composition comprising at least one constituent of sandalwood oil to the skin of said human.
The method of this invention is specifically directed to the use of a composition that is suitable for topical application. The initial discovery of the inventors was based upon the use of a soap manufactured by Karnataka Soaps & Detergents, Ltd., Bangalore, India, known and marketed as "Mysore Sandal Soap". The product packaging states that this soap contains natural Mysore sandalwood oil distilled by the government of Karnataka. It is known that this soap also contains vegetable ingredients. A second soap manufactured by Alfa Cosmetics, of Bombay, India, known as "Eastern Mysore's Pure Sandal Soap" has also been found effective in preventing and/or treating viral induced epidermal tumors, however, it is somewhat less effective. The "Eastern Mysore's Pure Sandal Soap" lists as its ingredients: palm stearin, rice bran fatty, coconut oil, caustic soda, perfume, sandalwood oil and preservatives. At the time the parent patent application was filed, the inventors had not isolated the active component from the sandalwood soap. However, at the time of filing the present application, the inventors, through further investigative effort, have determined that the sandalwood oil component of the soap was responsible for its prophylactic and therapeutic effects. As of the filing date of this application, the inventors are working towards the isolation of the active ingredient or active ingredients from the sandalwood oil. As used herein and in the claims, the term "sandalwood oil" shall mean: (1) the actual oil derived from the Santalum plant and/or (2) the active component or components (constituents) of said oil.
Sandalwood oil is a pale yellow, somewhat viscous, aromatic liquid obtained from sandalwood and is used chiefly in perfumes and soaps. Sandalwood is a close grained, fragrant, yellowish heartwood of a semi-parasitic plant of the genus Santalum (family Santalaceae), especially the fragrant wood of the true or white sandalwood, Santalum album. Approximately ten (10) species of Santalum are distributed through southeastern Asia and the islands of the South Pacific. The oil is obtained by steam distillation of the wood. Palm stearin or palm oil is an edible fat obtained from the flesh of the fruit of several palms and is typically used in soaps and lubricating greases. More particularly, palm stearin is a fraction of palm oil. Palm oil typically contains the fatty acid palmitic acid, which is a waxy, crystalline saturated fatty acid having the formula C 16 H 32 O 2 and may exist in the free acid form or in the form of esters (as glycerides) and most fats and fatty oils, and in several essential oils and waxes. Stearic acid (C 18 H 36 O 2 ) is one of the most common fatty acids and occurs and glycerides in most animal and vegetable fats, particularly in the harder fats with high melting points. A solid mixture of stearic and palmitic acids, "stearine", is used for making candles. The soaps are the sodium and potassium salts of stearic and palmitic acids.
One sandal soap listed rice bran fatty as an ingredient. Grains of cereals, such as rice and wheat, have a great deal in common with each other. They consist of three major structures: (1) the embryo or germ of the new plant; (2) the endosperm, which is the storer of nutrients for the germinating plant; and (3) the protective layers of the seed coat, which are regarded as bran by the miller. A typical bran composition (wheat on a dry weight basis) is: lignin-8%, cellulose-30%, hemi-cellulose-25%, starch-10%, sugars-5%, protein-15%, lipid-5%, and inorganic and other substances making up the remainder. It is believed that the rice bran fatty component of the sandal soap is in fact the lipid component from rice bran. It is further believed that there are a number of fatty acids with unusual structures that are found in rice bran. One such fatty acid is ricinoleic acid. Coconut oil is a fatty acid oil or semi-solid fat extracted from fresh coconuts and is used especially in making soaps and food products. The fatty acid composition of coconut oil is predominantly lauric acid. The composition of coconut oil has been thoroughly characterized and is known in the art. Caustic soda, also known as sodium hydroxide, is well known to be used in the production of soaps and detergents.
Other components such as preservatives and perfumes can be used in the sandal soaps of this invention. At this time, the complete characterization of those components are not available to the inventors. However, continued analysis has determined that the active component or components in the soap is the sandalwood oil. As will be set forth below, the inventors have elucidated that the sandalwood oil is the agent with the outstanding utility for treating or preventing human warts. In any event, as will be demonstrated below, it has been discovered that sandal soap and sandalwood oil is very effective in treating human warts.
The major components or constituents of sandalwood oil are cis-α-santalol and cis-β-santalol, about 50 and 20 weight % respectively. While any source of sandalwood oil is effective in the present invention, the Indian oil is preferred. Oxidation products may also be present in the oil, such as β-santalic acid and α-tetrasantalic acid. Table I sets forth the constituents of a fresh sandalwood oil and an old oil.
TABLE I______________________________________Comparative composition of "Fresh" and "Old"Samples of Sandalwood Oil Weight Percentage CompositionCompound Fresh Oil Old Oil______________________________________santene 0.01 0.05α-pinene* -- 0.02camphene* -- 0.02acetic acid -- 0.02teresantalal -- 0.04α-santalene 0.82 1.30trans-α-bergamotene 0.12 0.11epi-β-santalene 0.97 1.40β-santalene 1.40 1.90γ-curcumene 0.04 0.06β-bisabolene 0.07 --β-curcumene 0.13 --α-eka-santalal 0.07 0.49ar-curcumene 0.26 0.55β-eka-santalal 0.01 0.19(E)-nerolidol 0.06 --β-bisabolol 0.64 0.04α-santalal 2.90 7.70(Z)-trans-α-bergamotal 0.10 0.30α-bisabolol 0.26 --cis-α-santalyl acetate -- 4.40β-santalal 0.56 1.80dihydro-α-santalol 0.38 --cis-β-santalyl acetate -- 2.50cis-α-santalol 50.00 22.00(Z)-trans-α-begamotol 3.90 1.30nuciferyl acetate.sup.+ -- 0.33trans-α-santalol 0.56 .040epi-β-santalol 4.10 2.10cis-β-santalol 20.90 9.80trans-β-santalol 1.50 0.79cis-lanceol 1.70 0.29cis-nuciferol 1.10 0.75spirosantalol 1.20 0.47______________________________________ *presumed impurities .sup.+ probably cisnuciferyl acetate
The chemical make-up of a sandalwood oil varies slightly from source to source, however, α- and β-santalol make up over 65% of the oil. Table II sets forth the chemical make up of Chinese and Indian oils.
TABLE II______________________________________Comparative chemical composition ofIndian and Chinese sandalwood oil Percentage CompositionCompound Chinese Oil Indian Oil______________________________________tricyclo-eka-santalal 0.63 ca 0.30α-santalene 0.68 1.13trans-α-bergamotene ca 0.50 ca 0.10β-santalene.sup.+ 0.93 0.35β-santalene.sup.+ 1.37 0.63ar-curcumene 0.43 ca 0.50α-santalol.sup.+ 49.99 48.44β-santalol.sup.+ 3.78 4.19β-santalol.sup.+ 18.12 24.57nuciferol.sup.+ 3.14 5.45β-santalal 3.44 1.91α-santalal ca 0.20 0.53______________________________________
The santalol content also varies slightly from species to species of Santalum. Table III sets forth the santalol content of various Santalum species.
TABLE III______________________________________Santalol content of various Santalum species Percentage compositionSantalum Species Origin α-santalol β-santalol______________________________________S. album (1)* China 14.6 7.3S. album (4) India 46.6-59.9 24.6-29.0S. album (5) Indonesia 7.1-48.6 8.7-25.2S. yasi (1) Fiji 54.0 32.8S. papuanum (1) Papua, New Guinea 26.3 15.5S. spicatum? (3) Australia 27.9-35.3 4.0-29.2unknown (1) India 3.0 10.8______________________________________ *No. of samples
In a further embodiment of this invention, the method of preventing or treating viral-induced tumors uses sandalwood oil that is in a pharmaceutically acceptable carrier such as oleaginous ointment for topical administration.
In another embodiment of this invention, the active component or components of the sandalwood oil are disclosed for the prevention or treatment of viral-induced tumors.
There is further disclosed a prophylactic and therapeutic composition for the prevention and treatment of viral-induced tumors in mammals comprising sandalwood oil extract thereof or a derivative thereof in a pharmaceutically acceptable carrier.
In particular, the sandalwood oil itself and/or the extracts (active components) of the oil described herein are used for the preparation of prophylactic and therapeutic compositions for the treatment and prevention of viral-induced tumors in humans. Preferably, the compositions useful in the method are topically applied to the human in need of such therapy.
The method of the present invention neither destroys healthy, uninfected tissue nor results in any local or systemic side effects, scarring, disfigurement or discomfort to the human treated. Furthermore, the use of the present method results in the destruction of latent viral DNA found in the tumor and the surrounding tissues so that instances of incomplete resolution and tumor recurrence are prevented. The method includes the use of the sandalwood or an extract derived therefrom, for the administration to an area of the human which is anticipated to evidence viral-induced tumor growth, or an area which presently exhibits viral-induced tumor growth (i.e., warts) to prevent or eliminate the viral-induced tumor. In accordance with the method according to this invention, "regular use of the sandalwood oil" is meant to mean application of the sandalwood oil at least once a day to the body surface containing the wart(s). A further embodiment of the method of this invention comprises washing the affected area of the body with the soap, rinsing the area and then placing a small amount of soap residue or oil on the tumor to be treated. It has been determined through clinical evaluation that once the method of this invention is initiated, the warts begin to shrink, no matter what size, and will totally disappear after a period of two to four weeks of treatment, or less if the oil is applied.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is based, in part, on the discovery that a commercially available soap manufactured by the aforementioned companies is useful for the treatment of viral-induced tumors in humans. More specifically, the invention is directed to the discovery that sandalwood oil is the active component of the soap.
The initial chemical analysis was conducted as follows. 2.5 g of the sandal soap was dissolved in 15 ml of purified water. The pH was determined to be about 10.26. This solution was extracted, after acidification, with methylene chloride. The methylene chloride extract was dried over sodium sulfate and the volume was adjusted to 40 ml. The extract was diluted 10-fold and subjected to Gas Chromatography Mass Spectrometry (GC-MS) analysis. The analysis was performed on a Finnigan Model 4500 GC/MS system equipped with an HP-5890 Series II gas chromatograph and Galaxy 2000 data system. The semi-volatile GC column was a 30 meter by 0.32 mm RTX-5 capillary column. The temperature of the column was held at 40° C. for 1 minute, and then increased at 10° C./minute to a final temperature of 270° C.
Conversion of the hydroxide ion concentration was carried out using the definition of pH (-log[OH - ]=14-pH]. It was determined that the concentration of sodium hydroxide equivalents was about 0.015% by weight.
GC-MS analysis confirmed that no salicylic acid was present, a known agent for the treatment of warts. The fatty acids, dodecanoic, tetradecanoic, hexadecanoic, oleic and octadecanoic, were present. The weight ratio of dodecanoic; tetradecanoic; hexadecanoic; oleic; octadecanoic was 7:3.4:50.1:32:6.7. The ratio of hexadecanoic acid to oleic acid in palm oil is about 34 to 43% hexadecanoic acid to about 38 to 40% oleic acid. This analysis indicates that the soap was most likely derived from palm oil.
No other peaks were evident from this GC-MS analysis of the methylene chloride extract of the sandal soap at a detection limit after dilution of 1% by wt. As set forth below, the components of the sandalwood oil were found effective against human viral-induced tumors.
EXAMPLE 1
One inventor of the present invention is a pediatrician, actively engaged in the medical practice. Typically, pediatricians are constantly exposed to the HPV, which causes warts in humans. The inventor has had numerous occurrences of warts over the last 10 years, for which all available methods of treatment have been used, including excision using liquid nitrogen and various salicylic acid preparations. All of these methods of treatment failed to completely eradicate the warts. Typically, the warts became secondarily infected and were very painful. With conventional treatment, the warts subsided, however they only returned after a period of time. This inventor also developed a painful wart in between her fourth and fifth toes of her right foot which were scraped and then treated with commercially available creams known as Vytone and Lachydrin by a Dermatologist. Despite continued treatment, the warts recurred and were a constant source of aggravation. The inventor also developed a large wart on her left thumb, about 3 mm in diameter with dark spots on the surface. Subsequent to the appearance of the wart on the thumb, Mysore Sandal Soap was obtained and, after 4 to 5 days of use (washing twice daily), the wart on the thumb became smaller (appeared to shrink), reduced down to about 2 mm in diameter and continued to decrease in size until it completely disappeared after three weeks of treatment.
The inventor then began to wash (twice daily) the wart on her foot, which at the beginning of therapy was about 5 mm in diameter. After one week of daily applications of the sandal soap, the pain of the tumor had decreased and the wart was beginning to shrink in size. After a second week of washing and rinsing the tumor with the sandal soap, the inventor began to leave a small amount of soap residue on the affected area. No irritation or redness resulted from the soap residue and the tumor continued to decrease in size and totally disappeared after the third week of such usage.
EXAMPLE 2
A second individual, a four (4) year old black female, presenting a huge (about 4 mm), raised, wart on her right hand, began treatment of the wart with sandal soap. After about two weeks of treatment, (washing twice a day), the tumor had reduced to a small black dot and at the third week of treatment, the tumor was completely gone.
EXAMPLE 3
A seven (7) year old white male presented warts on each foot; one being about 3 mm in diameter, with raised dark spots on the surface and the other about 4 mm labulated and flesh-colored. These tumors were washed twice daily with the sandal soap. After one week of therapy, the tumors were visibly smaller and at that time, soap residue was allowed to remain on the tumor and surrounding tissue after washing. After two weeks, the tumors were completely gone and no new tumors were evident.
EXAMPLE 4
A ten (10) year old white female presented a large, 3 mm raised and fleshy wart on the dorsum of her right hand. Administration of the sandal soap began and after two weeks of treatment, the tumor shrunk to approximately half its size.
EXAMPLE 5
5 grams of the Mysore Sandal Soap was dissolved in 15 ml of distilled water. The pH of the solution was adjusted to 5.5 with HCl and this mixture was then extracted with methylene chloride. The methylene chloride extract is dried and the volume reduced to about 20 ml. This methylene chloride extract is then topically applied to a human wart. Application is to occur twice daily. After one to two weeks of treatment, the viral-induced tumor will have been eliminated.
EXAMPLE 6
Equal parts by weight of rice bran fatty acids and sandalwood oil is prepared. A cream suitable for topical use is prepared by mixing 1 gm of the rice bran/sandalwood oil composition with 20 gms of a balm, which comprises a mixture of petrolatum, mineral oil and wood alcohol. The cream is useful for minor irritations and in the treatment of viral infections which produce skin lesions or warts.
EXAMPLE 7
A third year medical student who had recurrence of plantar warts after surgical removal, used the sandal soap for four (4) weeks for washing the warts and was told to leave a small residue of soap on the warts after washing. The warts started shrinking as early as the first week and they totally disappeared after the fourth (4th) week and have not recurred.
EXAMPLE 8
A sixteen (16) year old white male subject presented a plantar wart on the foot that had recurred after surgical removal. The subject began using the sandal soap and after a period of about 3 weeks, the wart was totally gone and has not recurred. This subject washed the plantar wart with the sandal soap at least twice daily.
EXAMPLE 9
A third year, white, female medical student presented warts on her fingers. She had previously used salicylic acid preparation, but the warts had recurred. After use of the sandal soap, twice daily for about 1 week, the warts started shrinking and in about three (3) weeks, the warts totally disappeared and have not recurred.
EXAMPLE 10
One adult white male had chronic seborrheic dermatitis on the face and scalp. Upon daily administration of the sandal soap to the scalp and face, a significant improvement in his dermatologic condition was obvious. He found sandal soap was more effective in treating his condition than expensive shampoos and steroid creams which he previously used.
EXAMPLE 11
An adult white male and female presented psoriasis lesions on hands and arms. After approximately 1 week of treatment with the sandal soap, great improvement in this condition resulted. Twice daily applications of the sandal soap to the affected areas, significantly reduced flaking and dryness. The use of expensive steroid creams was significantly reduced by these subjects as the sandal soap therapy significantly reduced the psoriasis lesions. This soap could also be beneficial for allergic and eczematous rashes.
EXAMPLE 12
A fifty (50) year old white female presented with a plantar wart embedded inside a callous on her right foot which had recurred after several treatments which included surgical removal, freezing, etc. by a dermatologist. After about four (4) weeks of treatment with the sandal soap, the wart was totally gone and so was the pain and discomfort, which disappeared after the total resolution of the deeply embedded plantar wart on her right foot.
At the time of filing this application, further clinical work is underway to refine the method of the present invention and to further characterize the active components of the sandalwood oil.
At this time, a total of fifteen (15) individuals have undergone the inventive therapy and all 15 experienced the eradication of their palmar or plantar warts. The application of the sandal soap at least twice daily with occasional placement of soap residue on the warts, results in disappearance of the warts in about four (4) weeks. Deeply embedded warts took up to eight (8) weeks to resolve. Of the 15 individuals treated to date, twelve (12) were previously treated with salicylic acid preparations, liquid nitrogen or surgical techniques. In all twelve (12) cases, the warts reappeared. Upon reappearance of the warts, the subjects enrolled into the sandal soap study and have successfully completed their course of therapy and the warts have failed to reappear. It was noted that the individuals that had previously received salicylic acid treatments were slower to respond to the inventive therapy when warts were covered by scar tissue. However, in all cases, the warts had disappeared within four (4) to eight (8) weeks and recurrence of warts had not yet been detected.
EXAMPLE 13
Molluscum contagiosum is a skin disease caused by DNA pox virus and is characterized by the appearance of small, discreet lesions, in groups, on the face, arms or genitalia. The lesions are firm and pearly white with a sharply indented central core and yield an infectious filtrate which produces the disease when inoculated into human volunteers. The disease, which may be epidemic in children, occurs in all ages and is world-wide in distribution. Two subjects with Molluscum contagiosum were treated for about four (4) weeks using the sandal soap of the present invention. One of them had about twenty-five (25) large and small lesions. Some of the lesions were greater than 1 cm in diameter; the smaller lesions were about 5 mm in diameter. Application of the sandal soap occurred at least once per day, with a small amount of soap left behind on the lesions and the lesions disappeared in about four (4) weeks. The lesions failed to reappear since resolution.
EXAMPLE 14
The sandal soap according to the invention has also been found effective against the flaky rashes of psoriasis to seborrheic dermatitis, eczematous rash and dry skin. Individuals with the above recited conditions, upon use of the sandal soap, experienced a considerable decrease in itching, redness and flakiness subsequent to the use of the sandal soap. Also, the use of steroid creams was considerably reduced when the sandal soap was used in the management of the above recited rashes.
EXAMPLE 15
Adolescents and adults presented with facial acne and were instructed to use the sandal soap on a regular, daily basis. After about two (2) weeks of therapy, the presence of facial acne had decreased significantly or disappeared. Sandal soap was effective in eradicating pustular acne also. This work evidences that the sandal soap has anti-bacterial characteristics also which indicates its efficacy towards the control of Streptococcus and Staphylococcus skin infections.
EXAMPLE 16
A pediatrician colleague of the inventors, who had palmar warts for the last fourteen (14) years that kept recurring after the available, conventional treatment for warts, including use of salicylic acid preparation, used sandal soap for five (5) weeks with total resolution of the palmar wart that has not recurred.
EXAMPLE 17
A 27 year old married female with an abnormal pap smear due to HPV, as per her gynecologist, used sandal soap to wash her genital area whenever she took her bath and also sat in soapy water from sandal soap in her bathtub at least a couple of times per week. When the pap smear was repeated six (6) months later, it is reported to be normal and the HPV was not detected.
EXAMPLE 18
A 46 year old Asian female presented with almost innumerable warts on both heels. The subject had endured these warts for over seven (7) years and the standard therapies of freezing, cutting, salicylic acid the like (administered by a Dermatologist) had failed to resolve the malady. The Dermatologist informed the patient that her condition was not subject to the standard therapies and that she had to learn to live with these warts. Prior to the time the sandalwood oil treatments began, the patient was forced to cut the warts so that walking across a carpet was possible. The patient experienced pain and embarassment due to the numerous warts.
At the initial examination, the warts were very large, pigmented and painful. The skin around the warts was very dry with heavy callous formations. The left heel had 36 warts, one of them having dimensions of 1.4 cm by 8 mm and 6 mm in height. A second large wart measured 0.8 cm by 0.8 cm and was 5 mm in height. The remaining warts were in the range of 3-4 mm in diameter and height. The right heel had at least 40 warts with one very large wart that measured about 1 cm by 6 mm and about 4 mm in height. The remaining warts were 4-5 mm by 3-4 mm and 2-3 mm in height.
The patient also presented with 3 warts on her left hand which had returned after the standard treatments of freezing, cutting and use of salicylic acid had failed to resolve the condition. 2 warts were on her index finger and measured about 0.5 cm by 4 mm by 2 mm. One wart was on her thumb and measured about 3 mm by 2 mm by 2 mm.
The patient was supplied about 10 cc of pure (not diluted) Indian sandalwood oil. The patient was instructed to wash the tumors prior to application of the oil and to use a pumice stone on her heels to remove the calluses and dry skin. A drop of oil was placed on each lesion and rubbed on the wart each evening prior to retiring to bed. Therapy began on Jul. 12, 1998.
At the first follow-up visit on Jul. 23, 1998, the warts on the left hand had disappeared. The patient stated that within a few days of beginning treatment, the warts darkened and then scabbed over. By the eleventh day of therapy, the warts on her hand had disappeared, except that a small dark spot (scab) remained on the thumb.
Out of the 36 warts on the left heel, 26 had disappeared while the remaining 10 were totally flattened with dried residual wart tissue at the site of the wart. 30 out of the 40 warts on the right heel had resolved and disappeared. The remainder were flat with residual dried wart tissue.
A second follow-up exam took place on Jul. 29, 1998 and it was observed that the small dark spot on the left thumb was gone as were the remaining warts on the right heel. The right heel was smooth and shiny and completely free of warts. The left heel was clear of tumors except that 3 small areas still existed with dried wart tissue. The patient and inventors were very pleased with the rapid (about 21/2 weeks) elimination of the warts and are convinced that the sandalwood oil is a highly effective antiviral and antimitotic agent.
In light of these results, the inventors have concluded that sandalwood oil (or a component of the oil) is not only an antiviral agent against HPV, DNA pox virus and perhaps other viruses but it would also be a chemoprotective agent for skin cancers and an effective therapy for cancerous or precancerous lesions of the skin and the female genital tract.
Other Indications
Since warts are caused by human papillomaviruses (HPV)of different types and the sandalwood oil disclosed herein can eradicate this virus, it is contemplated that this composition may be useful in methods of eradicating other viral-induced tumors. Genital warts are also caused by HPV. Genital warts in women are a genuine nuisance and are very hard to eradicate. The sandalwood may also be useful to prevent other DNA viral lesions. Its effect on other DNA as well as RNA viruses needs further investigation. The fact that sandalwood oil appears to be extremely effective in eradicating palmar and plantar warts caused by the DNA HPV virus and also effective in treating Molluscum contagiosum rash caused by DNA pox virus supports its effectiveness against other DNA and RNA viruses.
It is proposed that the continued use of sandalwood oil or the components of sandalwood oil (such as α- and β-santalol) would be effective for the prophylactic treatment of viral tumors and eradication of DNA viral infections and bacterial infections caused by streptococci or staphylococci.
During the clinical evaluation of the present invention, it has come to the attention of the inventors that the sandalwood oil, sandal soap and/or the effective components of the sandalwood oil are also very effective in preventing dryness of the skin. As mentioned in Example I, an inventor of the present application is a pediatrician and is constantly (i.e., at least 40 times per day) washing her hands after examining a subject. This constant washing with soaps as required in a hospital setting, results in severe dryness to the hands. The sandal soap was applied twice a day to the dorsum of her left hand. The sandal soap was not applied to the dorsum of her right hand while washing her hands. At the end of approximately two weeks, the skin on the dorsum of her left hand was smooth, soft and shiny which was in contrast to the dry rough skin on the top of her right hand.
Thus, the sandal soap and sandalwood oil described herein has also been found effective in preventing the flakiness and dryness associated with skin that is constantly subject to harsh detergents. In addition, the sandal soaps have shown to be active against seborrheic dermatitis and psoriasis.
From the studies disclosed herein, sandalwood oil demonstrated specific antiviral properties against HPV, DNA pox virus that causes Molluscom contagiosum and is also effective in the treatment of bacterial skin infections. The properties of sandalwood oil also include anti-inflammatory characteristics as it has demonstrated effective emollient properties for dry skin and psoriasis.
It is quite evident from the clinical experience to date, that the sandalwood oil of the present invention has been outstandingly effective in the treatment and elimination of warts. The complete eradication of the warts with no recurrence is truly a surprising result as the medical community still searches for a cost effective and efficacious method to control this human malady.
INDUSTRIAL APPLICABILITY
Viral-induced tumors, especially of the skin, are very common. These tumors are typically very difficult to treat, control and prevent. The medical community has searched for decades for new therapies to treat this common human malady. The present invention provides a simple and cost-effective method to treat and prevent these viral-induced tumors.
As mentioned above, the term "sandalwood oil" is meant to include the oil itself, and any active component or components that are isolated therefrom. At the time of filing this patent application, the inventors are diligently pursuing the isolation of the active component or components and believe that such can be accomplished without excessive experimentation.
Many modifications may be made to the invention herein without departing from the basic spirit or scope of the invention. Accordingly, it will be appreciated by those skilled in the art, that within the scope of the appended claims, the invention may be practiced by means other than has been specifically described herein.
|
The present invention provides a method for the prevention and treatment of viral-induced tumors, more specifically, human warts. The method uses sandalwood oil and/or derivatives from the sandalwood oil to prepare medicaments for the prevention and treatment of viral-induced tumors (i.e., warts caused by the human papillomavirus (HPV)) in humans. The method of the invention comprises the topical administration of the sandalwood oil or a composition derived therefrom to the human epidermis and/or to the genital tract as needed. The present invention is also concerned with a unique antiviral composition useful for topical application. The antiviral composition according to this invention is also effective against other DNA viruses such as the DNA pox virus that causes Molluscum contagiosum and may be effective against other DNA viruses such as AIDS virus and RNA viruses. The sandalwood oil compositions are also effective against genital warts and HPV of the genital tract and will prevent cancer of the skin and cervix.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of a copending original application, Ser. No. 555,778 filed Mar. 6, 1975, by Robert H. Canterbury, entitled "PRESSURE BALANCED WELL SERVICE VALVE" now U.S. Pat. No. 3,987,848.
BACKGROUND OF THE INVENTION
This invention involves improvements in methods of injecting treating fluid into low-pressure oil well formations. More specifically, this invention discloses improved methods for treating low-pressure wells utilizing a partially pressure balanced valving system. The known method of treating low-pressure wells with injection fluids utilizes several known treating valves which have spring loaded checkvalve structure for allowing injecting of the fluids in precontrolled amounts into the formations.
This known method is of the type disclosed in U.S. Pat. No. 3,713,490, in the 1964-1965 World Oil Composite Catalog, pages 3680 and 3681, and in the Burt U.S. Pat. No. Re. 22,483. Apparatus useful in the known method of fluid injection is of the type as disclosed in U.S. Pat. Nos. 2,268,010, Re. 22,483, and U.S. Pat. No. 3,802,507.
The above mentioned method and valving devices utilize a coil spring biasing means on a checkvalve member to provide well injection valve service. The basic disadvantage with these devices and their method of operation is that the biasing means utilized must be of sufficient strength to provide a biasing force exceeding the hydrostatic pressure of the column of fluid in the tubing above the valve.
In some of the deeper wells, this results in having to use a very heavy and stiff biasing spring to obtain proper operation of the injection valve. Because of this requirement, the valve usually operates very few times successfully and becomes weakened or breaks during the method of operation.
As an alternative to the extremely heavy and stiff spring, some valve manufacturers have tried to use extremely small valve seat areas to reduce the force of hydrostatic pressure on the spring. Since the resultant downward force on the spring is determined by the pressure above the valve member, multiplied by the cross-sectional area of the valve flow area it is applied to, these designs were made with small flow areas to reduce the downward force of the column of fluid.
While these designs were partially successful in reducing spring failure, they resulted in causing an even greater problem and that involved plugging of the valve flow area. Since most tubing contains some sediment, scale, rust and other foreign matter, the injection of treating fluids and acids down the tubing always breaks loose a quantity of this material which accumulates at the valve mechanism and effectively plugs it up.
The present invention overcomes these disadvantages by providing a method wherein fluid may be injected into a well through apparatus utilizing only a moderate biasing force to hold the hydrostatic pressure of the column of fluid in the tubing. This method utilizes a partial pressure balancing of the valving mechanism to reduce the hydrostatic force on the biasing means and prevent plugging of the valve flow area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of the injection valve assembly utilized in this invention.
FIG. 2 is a partial schematic cross-sectional illustration of an alternate structure for use in the method of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the pressure-balanced service valve 10 is shown in cross-section having a generally tubular elongated body 11 in which is slidably located a valve member 12. A compression coil spring 13 abuts valve member 12 and urges valve member 12 into sealing engagement with valve seat 14 secured to the inner wall of housing 11. A slidable abutment base 15 is located in the bottom of housing 11 and is sealingly engaged therein by means of circular seal 16. Abutment base 15 provides a slidable base for the abutment of spring 13. A housing cap 17 is secured at the lower end of housing 11 and closes off the bore passage therethrough. A threaded adjustment member 18 is threadedly engaged in cap 17 extending upward into housing 11 for abutment with base 15 to provide compression adjustments for spring 13.
Likewise, valve member 12 has a widened base 19 to provide an abutment surface for the upward end of coil spring 13. Valve member 12 comprises upper generally spherical seating end 12a, an elongated generally cylindrical valve body 12b, and the aforementioned spring abutment face 19 at the lower end thereof. Housing 11 has an inwardly projecting shoulder 20 forming an annular partition in housing 11 through which member 12 passes, with section 12b being in close proximity to the inner bore 21 in partition 20. One or more circular seals 22 are provided in grooves 23 in inner bore 21 which circular seals sealingly contact elongated valve body 12b.
The inner bore passage 24 of the tubing string is divided by the annular sealing shoulder 14 and sealing partition 20 into a valve flow chamber 25 and a pressure-balance chamber 26. Flow of fluids down the tubing string 27 may progress through bore 24 and chamber 25 into the formation and flow by means of a bypass channel 28 into chamber 26. Fluids in chamber 26 are restricted therein by the various seal members 16 and 22 so that no fluid may escape therefrom.
Likewise, fluid flow between chambers 25 and 26 is also prohibited. The flow of fluids through bypass channel 28 from bore passage 24 to pressure chamber 26 results in a pressure force upward on member 12 which is directly proportional to the area swept by circular seals 22, said area being designated in FIG. 1 by the dimension A 2 and being circular in shape or corresponding in shape to the cross-sectional configuration of section 12b of valve member 12.
Likewise, a downward pressure occurs across the area atop valve member 12a, which pressure is equivalent to the area of the opening in valve seating shoulder 14, said area being designated at A 1 . The total resultant pressure acting on valve member 12 is thus related to the difference in areas A 1 and A 2 . This is respresented by the relation F = P(A 1 - A 2 ).
Thus, it can be seen that by varying the areas A 1 and A 2 the resultant differential pressure on valve member 12 may be made as large or as small a proportion of the downward pressure in the tubing as required or desirable. In a deep well requiring a high hydrostatic pressure in the tubing because of the height of the fluid column therein, the difference A 1 - A 2 would advantageously be made small because of the high pressure involved. In a shallower well, the difference A 1 - A 2 would preferably be made larger. Thus, the biasing force upward provided by spring 13 to maintain member 12 seated in valve seat 14 prior to the injection operation need only be an amount greater than the resultant differential pressure acting downward on valve member 12. As an alternative to altering the pressure differential area A 1 - A 2 for different depts of use, it is clear that a single value of A 1 - A 2 for generally mid-range depths may be selected and a fine tuning of the valve for each individual well depth may be obtained by the adjustment of threaded abutment screw 18 upward or downward as the case may be.
For the deeper wells, screw 18 is threaded upward to further compress biasing spring 13 and provide a greater biasing force against the greater hydrostatic head of the fluid column in the tubing. In the shallower wells, screw 18 should be threaded downward to relieve a portion of the biasing force of spring 13 upward against valve member 12 due to the lesser hydrostatic head of the shorter column of fluid in the tubing.
In typical operation, when it is desirable to place a treating fluid on the face of a formation with this invention, the characteristics of the formation including the formation pressure and formation depth are utilized to calculate the hydrostatic head of the fluid that will exist with a full column of fluid in the tubing. From these calculations, the downward resulting differential pressure on valve member 12 is calculated using the formula P × (A 1 - A 2 ) and the amount of spring biasing force required to overcome this is introduced by the adjustment of spring 18 against spring base 15 thereby compressing spring 13 to the calculated extent. This establishes a biasing force against valve member 12 calculated to be greater than the resulting downward pressure on member 12 when the valve is in place opposite the formation with a column of fluid thereabove.
The valve is then placed at the lower end of the tubing string below a standard packer such as that disclosed in U.S. Pat. No. 3,548,936 to Kilgore et al, dated Dec. 22, 1970 and U.S. Pat. No. 3,701,382 to Williams, dated Oct. 31, 1972. A bypass valve in the packer is opened and the string is run in the hole with the well fluid being allowed to flow through the bypass valve in the packer and into the tubing string to offset buoyancy of the string. After the string is located properly, with the injection valve 10 in close proximity to the formation face, the packer is set by means such as wireline set, mechanical manipulation of the tubing, or hydraulic set, and the annulus below the packer near the formation is isolated from the rest of the annulus above the formation.
It may then be desirable to circulate out the well fluid existing in the isolated area of the annulus to prevent contamination of the formation by this fluid. This may be accomplished by opening a bypass valve in the packer and pumping the treating fluid into the tubing thereby displacing the well fluid up through the bypass valve into the annulus above the packer. The pumping of fluid through valve 10 during this displacement is accomplished by pressuring the tubing a sufficient amount to overcome the resultant biasing force upward on spring 13 on member 12, thereby forcing member 12 downward through partition 20, opening the bore through seat 14 and communicating ports 30 in the wall of housing 11 with flow area A 1 .
After displacement of the well fluid has occurred and it is calculated the treating fluid has reached valve 10 and into the isolated area of the annulus, the bypass valve in the packer is closed by manipulation of the string or by other known means and injection of the treating fluid into the formation is accomplished by either continuing the fluid pressure on the tubing or else by increasing the pressure on the tubing to provide a faster injection rate. After the calculated desirable amount of treating fluid has been injected into the formation, it is usually desirable to allow the fluid to set in the formation an extended period of time to maximize the desirable effect gained from the treating fluid. This may be done by releasing pressure on the tubing which thus removes a major portion of the resulting downward differential pressure on valve member 12. The remaining differential pressure on 12 is insufficient to maintain spring 13 compressed and thereby spring 12 moves back upward to set in seat 14 closing off flow from the formation back through the tubing string.
After the treating fluid has been held in the formation the desired period of time, the fluid may be removed from the formation either by means of a shear sleeve or other type of circulating valve between the packer and the injection valve 10 or else the bypass valve through the packer may be opened to allow the fluid to move back up the annulus. After the fluid has been removed from the formation, the string may be pulled from the casing and the treating valve removed from the tubing string to be reused in other wells an indefinite number of times. Thus, it can be seen that by using a pressure relief bypass channel 28, the hydrostatic pressure in the tubing string may be communicated with the lower side of the valve member as well as the upper side and, by proper selection of the pressure areas on valve member, a desirable differential area A 1 - A 2 may be established requiring only a relatively resilient low force biasing spring 13 to overcome the downward pressure on member 25 arising from the hydrostatic head. By utilizing a hydrostatic balancing chamber 26 isolated from the flow chamber 25 yet in communication with member 12, a partial pressure-balancing of member 12 may be achieved in order to offset a large portion of the downward hydrostatic pressure existing under the column of fluid in the tubing without allowing any of the fluid to leak out of the pressure-balancing area and into the flow area.
Referring now to FIG. 2, a partial cross-sectional area of flow member 10 is shown wherein a modification of flow ports 30 is disclosed. In the embodiment of FIG. 1, a number of ports 30 through the wall of housing 11 may be varied from one to as many as will fit the periphery of the housing around chamber 25. Preferably, the flow areas through ports 30 are made as large as structurely feasible to provide as low resistance flow as possible.
In the second embodiment in FIG. 2, a modification of the flow ports 30 is provided to obtain additional action from the treating fluid in the formation area. In this embodiment, the number and location of flow port means through the wall of housing 30 are more critical than the location and configuration of ports in FIG. 1. In this embodiment, a number of spraying nozzels 31 are secured in the port openings 30 by means such as welding or threading. The spray nozzels are directed at the formation face and into the annular area around valve 10 so that during the injection of the treating fluid, the fluid is sprayed into the formation face and around the tool to provide a washing jet action to further increase the desirable effects of the treating fluid on the formation. For instance, in some of the wells to be treated, one of the problems attempted to be overcome involves the build-up of paraffin in the formation flow area and in the perforations in the casing. The build-up of paraffin can greatly reduce and even stop the flow of hydrocarbons from the formation into the borehole. Some paraffin build-ups are extremely hard to dissolve and the treating fluids must be strong and must be left in place a great period of time to be effective against such build-ups.
In these circumstances, use of the embodiment in FIG. 2 is particularly advantageous in that the agitation of the treating fluid against the formation face serves to increase many-fold the action of the fluid on the paraffin deposits. Operation of the tool of FIG. 2 is substantially identical to that of the embodiment of FIG. 1.
The jetting system of FIG. 2 is also useful for allowing a washing action on the formation after the injection treatment has been accomplished. A washing fluid may be injected behind the treating fluid and sprayed through jets 31 against the formation to remove sediment, deposits, and residue from the injection treatment. Although certain preferred embodiments of the present invention have been herein described in order to provide an understanding of the general principles of the invention, it will be appreciated that various changes and innovations can be affected in the described valve structure without departure from these principles. For example, whereas a method utilizing a vertically upward acting valve member is disclosed, it is clear that the method also encompasses the use of said structure in an inverted configuration from that shown with a biasing means pushing the valve member downward and the resulting partial differential pressure on the valve member resulting in an upward force from the hydrostatic fluid pressure. Thus, all modifications and changes of this type are deemed to be embraced by the spirit and scope of the invention except as the same may be necessarily limited by the appended claims or reasonable equivalence thereof.
|
A method of injecting fluids into underground formations such as oil wells, and particularly advantageous for treating low-pressure formations having bottomhole pressures below normal tubing hydrostatic pressure, utilizes the steps of lowering into the borehole a tubing string, locating near the formation to be treated a partially pressure-balanced valve adapted to support a column of fluid in the string of tubing, and applying pressure to the column of fluid in the tubing to inject fluid through the valve and into the formation.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of International Patent Application No. PCT/CN2014/086679, filed Sep. 17, 2014, entitled “METHOD FOR DETERMINING INTEGRATED NETWORK LOSS RATE IN ULTRA-HIGH VOLTAGE ALTERNATING CURRENT CROSS-REGIONAL ENERGY TRADE,” by Ting Hu et al., which itself claims the priority to Chinese Patent Application No. 201310700875.8, filed Dec. 18, 2013, in the State Intellectual Property Office of P.R. China, entitled “METHOD FOR DETERMINING INTEGRATED NETWORK LOSS RATE IN ULTRA-HIGH VOLTAGE ALTERNATING CURRENT CROSS-REGIONAL ENERGY TRADE,” by Ting Hu et al., which are hereby incorporated herein in their entireties by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for determining an integrated network loss rate in UHV AC cross-regional electricity trading, and belongs to the field of line loss management and trading settlement related to UHV electricity trading.
BACKGROUND OF THE INVENTION
[0003] The background description provided herein is for the purpose of generally presenting the context of the present invention. The subject matter discussed in the background of the invention section should not be assumed to be prior art merely as a result of its mention in the background of the invention section. Similarly, a problem mentioned in the background of the invention section or associated with the subject matter of the background of the invention section should not be assumed to have been previously recognized in the prior art.
[0004] China has a vast geographic area, and energy resources and electricity loads are distributed very unevenly. The developments of astrong smart grids of ultra-high voltages (UHV) as a backbone network frame can implement cross-regional, long-distance, high-power electric power transmissions and exchanges, and optimization of wide-range power resource distributions. An UHV grid refers to a 1000 kV AC grid or ±800 kV DC grid, which is characterized by high voltages, great power, small losses, long power transmission distances and a single circuit structure. In China, UHV projects that have been put into operation at present include the southeastern Shanxi-Nanyang-Jingmen 1000 kV UHV AC test and demonstration project, the Sichuan (Xiangjiaba)-Shanghai ±800 kV UHV DC transmission project, and the Jinping-South Jiangsu ±800 kV UHV DC transmission project.
[0005] The network loss rate is defined as system loss increment caused by power consumption or transmission of per unit increment under particular time and operation manner. The UHV integrated network loss rate can be calculated through the total loss of power (including a line loss, a transformer loss, and further including a convertor station loss for DC transmission) divided by the power-giving/outputting at the starting node/port in the system. The trading network loss is one of the main trading costs, in planning and trading settlement of UHV cross-regional electricity trading, effects of the network loss on the trading plan and settlement cost must be taken into account, it is necessary to correct or reduce the settlement power or bid price according to the size of the integrated network loss rate planned value. Thus, the method for determining the UHV integrated network loss rate planned value is scientific and reasonable directly relates to economic interests of the parties of the trading, and close attention is paid thereto by trading related parties.
[0006] At present, a theoretical calculation method of UHV AC integrated network loss rates uses a power system analysis program recognized in this field, for example, a power system analysis synthesis program (PSASP) developed by China's electricity academy, to make load flow calculation on an actual system (the load flow calculation is calculation of determining steady running state parameters of respective parts of the power system according to a given grid structure, parameter and generator, load and other elements' operating conditions), to obtain powers passing through the UHV AC line and the beginning and the end of the transformer, and then calculate theoretical values of integrated network loss rate corresponding to different transmitting powers of the UHV AC line. For high-voltage and long-distance transmission lines, power loss thereof mainly includes two parts: one is resistive loss, which is caused by heating of line resistance and is a function of line resistance, wire length and line current; the other is corona loss, which is caused by corona discharge formed by ionization of air around the wire under the action of a strong electric field and is affected by meteorological condition, conductor selection, operating voltage and other factors, where the corona loss is represented by ground conductance in a transmission line model. As line-to-ground parameters in an AC line model of a related program such as PSASP only takes shunt capacitance into account and omits ground conductance, if the integrated network loss rate is calculated directly using the result of the load flow calculation of the related program such as PSASP, actually only the resistive loss of the line is taken into account, but the corona loss of the line is not considered, the corona loss of the line at 110 kV or therebelow is very tiny and can basically be ignored, however, as the corona loss is directly proportion to the square of the voltage, the corona loss of EHV and UHV AC power transmission has been a greater value and must be considered. Therefore, the theoretical calculation value of the UHV AC integrated network loss rate obtained through the related program such as PSASP definitely has certain errors due to not considering the corona loss of the line.
[0007] The method for calculating the actual value of the UHV AC integrated network loss rate uses gateway power statistical data of a certain time period in actual project practice to calculate the integrated network loss rate, and the calculation result is more precise; however, as measurement accuracy, calculated error and other factors of a metering device, also have a certain error, and the method is calculated afterwards, in consideration of timeliness of trading settlement, the method cannot be directly applied to planning and trading settlement of UHV cross-regional electricity trading.
[0008] At present, in the planning and trading settlement of UHV cross-regional electricity trading, a method for determining a planned value of the integrated network loss rate has yet not existed, and a common method is setting a single fixed network loss rate. By taking the southeastern Shanxi-Nanyang-Jingmen 1000 kV UHV AC test and demonstration project as an example, the project starts from a transformer substation in southeastern Shanxi (Changzhi), via a transformer substation in Nanyang, Henan, and terminates at a transformer substation in Jingmen, Hubei, connects power grids in two big regions, North China and Central China, and is an important transmission channel through which the coal energy center in the northwest region transmits power to the load center in the mid-east region, and in the transaction planning and settlement process of the project, the planned value of the integrated network loss rate is uniformly set as 1.5%. Although using a fixed network loss rate is simple, the following problems still exist:
[0009] 1. The UHV AC integrated network loss rate varies with the change of the UHV transmission power, and the use of a fixed value has poor accuracy. Inaccurate determination of the integrated network loss rate will directly lead to inaccurate calculation of the settlement power in the UHV trading settlement, thereby affecting fairness of the transaction. It is found by statistically analyzing historical data of the UHV AC demonstration project in the past two years that, although the UHV AC integrated network loss rate is mostly maintained between 1.4%-1.5%, the minimum network loss rate is merely 1.22%, the maximum network loss rate is up to 2.17%, and the current method that plans the network loss rate as a fixed value regardless of the size of the UHV transmission power is evidently not reasonable.
[0010] 2. Scalability and extensibility are lacking. The UHV AC integrated network loss rate is closely related to the transmission power, when the UHV AC actual transmission power exceeds a historical data range of projection practice, the integrated network loss rate will vary greatly, the network loss rate cannot be corrected quickly according to the current method, and scalability and extensibility are poor. With respect to deficiencies of the use of the fixed value as the planned value of the UHV AC integrated network loss rate, it is feasible to consider, in combination with UHV AC transmission theoretical line loss calculation and actual line loss rate calculation results, using the least square method or a method of curve fitting with related software (e.g., Excel, SPSS, MATLAB) to obtain a function relation between UHV AC integrated network loss rates and transmission powers, to seek out a scientific and reasonable method for determining the planned value of the integrated network loss rate applied to UHV AC cross-regional electricity trading; as the UHV AC line network structure is relatively simple, generally, the integrated network loss rate and the transmitting power present a relationship of quadratic parabola.
[0011] Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
[0012] One of the objectives of the present invention is to provide a method for determining an integrated network loss rate in UHV AC cross-regional electricity trading. The method, with respect to the problem existing in the existing practice of using a fixed value as the integrated network loss rate in UHV AC electricity trading line loss management and trading settlement, puts forward fitting a curve relationship between integrated network loss rates and transmitting powers on the basis of theoretical calculations of the UHV AC transmission line loss, then uses a relational fitted curve between actual values of integrated network loss rates and transmitting powers calculated according to gateway power statistical data to perform geometrical average correction on the original curve, and finally causes planned values of the integrated network loss rates to be closer to the actual values according to a method for determining UHV AC integrated network loss rates according to a correction curve function relation, which greatly increases fairness of the trading settlement. The method of the invention is simple and easy to implement with the high accuracy, and applicable to planning and power settlement of regular or real-time UHV AC electricity trading. The invention provides a new idea and method for operation, management and trading settlement of UHV AC transmission lines.
[0013] In one aspect of the invention, the method for determining an integrated network loss rate in UHV AC cross-regional electricity trading comprises the steps of:
[0014] (a) by calculation according to the following formula, obtaining theoretical calculation values η theoretical of integrated network loss rates corresponding to different transmitting powers of a UHV AC line, which is:
[0000]
η
theoretical
=
Δ
P
R
+
Δ
P
C
+
Δ
P
T
P
[0000] wherein P is the UHV AC transmitting power, ΔP R is the resistive loss of the UHV AC line, ΔP T is the energy loss for main transformer of a UHV AC system; ΔP C is the corona loss of the UHV AC line;
[0015] (b) curve-fitting the different transmitting powers of the UHV AC line and the corresponding theoretical calculation values η theoretical of integrated network loss rates by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate, to obtain a fitted curve η 1 (P)=a 0 +b 0 ×P+c 0 ×P 2 of relations between the theoretical calculation values of UHV AC integrated network loss rates and transmitting powers;
[0016] (c) according to gateway power statistical data, determining an average transmitting power within respective different-duration time periods of the UHV AC system and obtaining through calculation according to the following formula an actual calculation value η actual of the corresponding integrated network loss rate in each time period, which is:
[0000]
η
actual
=
Δ
Q
Q
=
∑
i
SQ
i
(
+
)
+
∑
i
RQ
i
(
-
)
∑
i
SQ
i
(
+
)
[0000] wherein ΔQ is the total network loss power of the UHV AC system in each time period, Q is the total power-giving of the UHV AC system in the time period;
[0000]
∑
i
SQ
i
[0000] is the sum of power-giving of pressure-side gateways in all UHV main transformers in the time period, and
[0000]
∑
i
RQ
i
[0000] is the sum of power-receiving of the pressure-side gateways in all UHV main transformers in the time period;
[0017] (d) curve-fitting the UHV AC average transmitting powers and the corresponding actual calculation values η actual integrated network loss rates by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate, to obtain a fitted curve η 2 (P)=a 1 +b 1 ×+c 1 ×P 2 of relations between the actual calculation values of UHV AC integrated network loss rates and transmitting powers;
[0018] (e) selecting n+1 points, [P 1 ,η 1 (P 1 )],[P 2 ,η 1 (P 2 )] . . . [P i ,η 1 (P i )], . . . [P n+1 ,η 1 (P n−1 )], from the fitted curve of relations between the theoretical calculation values of UHV AC integrated network loss rates and transmitting powers, wherein P i is the minimum transmitting power of the UHV AC line, P n+1 is the maximum transmitting power of the UHV AC line,
[0000]
P
i
=
P
1
+
(
P
n
+
1
-
P
1
)
×
(
i
-
1
)
n
,
[0000] i=1, 2, . . . , n, n+1; then selecting n+1 points with the same abscissa, [P i ,η 2 (P i )],[P 2 ,η 2 (P 2 )[ . . . ]P i ,η 2 (P i )], . . . [P n+1 ,η 2 (P n+1 )], from the fitted curve of relations between the actual calculation values of UHV AC integrated network loss rates and transmitting powers, through geometric average correction, obtaining points, [P 1 ,√{square root over (η 1 (P 1 )η 2 (P 1 ))}],[P 2 ,√{square root over (η 1 (P 2 ))}] . . . [P i , √{square root over (η 1 (P i )η 2 (P i ))}] . . . [P n+1 ,√{square root over (η 1 (P n+1 )η 2 (P n+1 ))}], on a correction curve, and obtaining by fitting a correction relation η correct (P)=a 3 +b 3 ×P+c 3 ×P 2 between UHV AC integrated network loss rates and transmitting powers by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate;
[0019] (f) for UHV AC transmission projects with gateway power historical statistical data, in transaction planning and settlement thereof, substituting UHV AC planned average transmitting powers in a transaction time period into the correction relation η correct (P)=a 3 +b 3 ×P+c 3 ×P 2 , to obtain planned values of UHV AC integrated network loss rates; for UHV AC transmission projects without gateway power historical statistical data, in transaction planning and settlement thereof, substituting a UHV AC planned average transmitting power in a transaction time period into a theoretical calculation value fitted curve function relation η 1 (P)=a 0 +b 0 ×P+c 0 ×P 2 , to obtain calculating values of UHV AC integrated network loss rates.
[0020] In one embodiment, a method of dividing the respective time periods in step c is: recording changes of the UHV AC transmitting powers with hour data on the hour, the transmitting power of the starting hour on the hour in each time period being an initial power, and when varying amplitude of the transmitting power of the subsequent hour on the hour reaches a % (a value between 5% and 10%) of the initial power, entering into next time period.
[0021] In one embodiment, the n in step (e) is ∈{20, 21, 22, . . . 200}.
[0022] According to the present invention, the method has, among other things, the following advantages:
[0023] 1. Curve fitting is performed based on line loss theoretical calculation, correct of an actual value fitted curve calculated according to gateway power statistical data is taken as an adjustment means to determined the planned value of the UHV AC integrated network loss rate, avoiding the error brought about by simply using a certain method. In addition, with continuous accumulation of gateway statistical data, it is feasible to perform continuous deviation correction on the original fitted curve, which has high accuracy, strong persuasion and good reliability.
[0024] 2. Values of integrated network loss rates is determined according to a function relation between UHV AC integrated network loss rates and transmitting powers, which can better reflect a trend that the UHV AC integrated network loss rates vary with the transmitting powers, overcomes the disadvantage of poor accuracy of the use of fixed planned values of integrated network loss rates, and greatly reduces the deviation between planned network loss rates and actual network loss rates, causing UHV AC electricity trading settlement to be fairer and more reasonable.
[0025] 3. It is not restricted by time, it is feasible to be used in regular transaction line loss management and trading settlement, it is also feasible to be applied to real-time transaction, and the method is simple and easy to implement and has strong practicability.
[0026] 4. It has better scalability and extensibility. When the UHV AC transmitting power exceeds the scope of the original data, it is still feasible to rapidly determine the corresponding integrated network loss rate value according to the fitted curve.
[0027] These and other aspects of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein is affected without departing from the spirit and scope of the novel concepts of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. The drawings do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
[0029] FIG. 1 is a schematic flowchart of a method for determining an integrated network loss rate in UHV AC cross-regional electricity trading according to one embodiment of the invention.
[0030] FIG. 2 is a schematic diagram of a 1000 kV southeastern Shanxi-Nanyang-Jingmen UHV AC test and demonstration project according to one embodiment of the invention.
[0031] FIG. 3 is a schematic diagram of a relational fitted curve of theoretical calculation values of integrated network loss rates and transmitting powers of a UHV AC demonstration project according to one embodiment of the invention.
[0032] FIG. 4 is a schematic diagram of a relational fitted curve of actual calculation values of integrated network loss rates and transmitting powers of a UHV AC demonstration project according to one embodiment of the invention.
[0033] FIG. 5 is a schematic diagram of comparison between a fitted curve of theoretical calculation values, a fitted curve of actual calculation values and a correction fitted curve of integrated network loss rates and transmitting powers of a UHV AC demonstration project according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present 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 present invention to those skilled in the art. Like reference numerals refer to like elements throughout.
[0035] The terms used in this specification generally have their ordinary meanings in the art, within the context of the present invention, and in the specific context where each term is used. Certain terms that are used to describe the present invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the present invention. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting and/or capital letters has no influence on the scope and meaning of a term; the scope and meaning of a term are the same, in the same context, whether or not it is highlighted and/or in capital letters. It will be appreciated that the same thing can be said in more than one way. Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only and in no way limits the scope and meaning of the present invention or of any exemplified term. Likewise, the present invention is not limited to various embodiments given in this specification.
[0036] It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0037] It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions and/or sections, these elements, components, regions and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region or section from another element, component, region or section. Thus, a first element, component, region or section discussed below can be termed a second element, component, region or section without departing from the teachings of the present invention.
[0038] It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” to another feature may have portions that overlap or underlie the adjacent feature.
[0039] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including” or “has” and/or “having” when used in this specification specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
[0040] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present invention, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0041] As used herein, “around”, “about”, “substantially” or “approximately” shall mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning the terms “around”, “about”, “substantially” or “approximately” can be inferred if not expressly stated.
[0042] As used herein, the terms “comprise” or “comprising”, “include” or “including”, “carry” or “carrying”, “has/have” or “having”, “contain” or “containing”, “involve” or “involving” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.
[0043] The description below is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses. The broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the present invention should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present invention.
[0044] Referring to FIG. 1 , a flow of a method for determining an integrated network loss rate in UHV AC cross-regional electricity trading is shown according to one embodiment of the present invention. The method comprises the following steps.
[0045] First, at step (a), various typical operating manners representing a particular year are selected for theoretical calculation of integrated network loss rates, to calculate a power range that covers smaller values to UHV AC rated transmitting powers, theoretical calculation values η theoretical of integrated network loss rates corresponding to different transmitting powers of a UHV AC line are calculated according to the following formula:
[0000]
η
theoretical
=
Δ
P
R
+
Δ
P
C
+
Δ
P
T
P
[0000] wherein: P is the UHV AC transmitting power; ΔP R and ΔP T are respectively the resistive loss of the UHV AC line and the energy loss for main transformer of a UHV AC system calculated through the related program such as PSASP; ΔP C is the corona loss of the UHV AC line, as the corona loss is irrelevant to the line current, it is a constant relative to the change of the power and can be estimated in combination with weather conditions of regions where the UHV AC line passes and actual measured values of the corona loss under various weather conditions.
[0046] At step (b), the different transmitting powers of the UHV AC line and the corresponding theoretical calculation values η theoretical integrated network loss rates are curve-fitted by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate, to obtain a fitted curve η 1 (P)=a 0 +b 0 ×P+c 0 ×P 2 of relations between the theoretical calculation values of UHV AC integrated network loss rates and transmitting powers.
[0047] At step (c), according to gateway power statistical data, an average transmitting power within respective different-duration time periods of the UHV AC system is determined and an actual calculation value η actual of the corresponding integrated network loss rate in each time period is obtained through calculation according to the following formula, which is:
[0000]
η
actual
=
Δ
Q
Q
=
∑
i
SQ
i
(
+
)
+
∑
i
RQ
i
(
-
)
∑
i
SQ
i
(
+
)
[0000] wherein ΔQ is the total network loss power of the UHV AC system in each time period, Q is the total power-giving of the UHV AC system in the time period;
[0000]
∑
i
SQ
i
[0000] is the sum of power-giving of pressure-side gateways in all UHV main transformers in the time period, and
[0000]
∑
i
RQ
i
[0000] is the sum of power-receiving of the pressure-side gateways in all UHV main transformers in the time period.
[0048] In one embodiment, a method for dividing the respective time periods is: recording changes of the UHV AC transmitting powers with hour data on the hour, the transmitting power of the starting hour on the hour in each time period is an initial power, and when varying amplitude of the transmitting power of the subsequent hour on the hour reaches a % (a value between 5% and 10%) of the initial power, entering into next time period.
[0049] At step (d), the UHV AC average transmitting powers and the corresponding actual calculation values ilactual of integrated network loss rates are curve-fitted by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate, to obtain a fitted curve η 2 (P)=a 1 +b 1 ×P+c 1 ×P 2 of relations between the actual calculation values of UHV AC integrated network loss rates and transmitting powers.
[0050] At step (e), selecting n+1 points, [P 1 ,η 1 (P 1 )],[P 2 ,η 1 (P 2 )] . . . [P i ,η 1 (P i )], . . . [P n+1 ,η 1 (P n+1 )], from the fitted curve of relations between the theoretical calculation values of UHV AC integrated network loss rates and transmitting powers, wherein P 1 is the minimum transmitting power of the UHV AC line, P n+1 is the maximum transmitting power of the UHV AC line,
[0000]
P
i
=
P
1
+
(
P
n
+
1
-
P
1
)
×
(
i
-
1
)
n
,
[0000] i=1, 2, . . . , n, n+1; then selecting n+1 points with the same abscissa, [P 1 ,η 2 (P 1 )],[P 2 ,η 2 (P 2 )] . . . [P i ,η 2 (P i )], . . . [P n+1 ,η 2 (P n+1 )], from the fitted curve of relations between the actual calculation values of UHV AC integrated network loss rates and transmitting powers, through geometric average correction, obtaining points, [P 1 ,√{square root over (η 1 (P 1 )η 2 (P 1 )}],[P 2 , √{square root over (η 1 (P 2 )η 2 (P 2 ))}] . . . [P i ,√{square root over (η η (P i ))}], . . . [P n+1 , √{square root over (η 1 (P n+1 )η 2 (P n+2 ))}], on a correction curve, and obtaining by fitting a correction relation η correct (P)=a,+b,×P+c,×P 2 between UHV AC integrated network loss rates and transmitting powers by using the least square method in a rectangular coordinate system where the abscissa is the UHV AC transmitting power and the ordinate is the integrated network loss rate.
[0051] At step (f), for UHV AC transmission projects with gateway power historical statistical data, in transaction planning and settlement thereof, UHV AC planned average transmitting powers in a transaction time period (obtained by the UHV AC planned transaction power value in the transaction time period divided by a time length) are substituted into the correction relation η correct (P)=a,+b,×P+c 3 ×P 2 , to obtain planned values of UHV AC integrated network loss rates; for UHV AC transmission projects without gateway power historical statistical data, in transaction planning and settlement thereof, substituting a UHV AC planned average transmitting power in a transaction time period into a theoretical calculation value fitted curve function relation η 1 (P)=a 0 +b 0 ×P+c 0 ×P 2 , to obtain calculating values of UHV AC integrated network loss rates.
[0052] Without intent to limit the scope of the invention, specific embodiments of the method of the present invention is further described below in details by using the UHV AC transmission projects in China as examples.
[0053] The method for determining an integrated network loss rate in UHV AC cross-regional electricity trading according to the present invention is applied to monthly line loss management and trading settlement of electricity trading of the southeastern Shanxi-Nanyang-Jingmen 1000 kV UHV AC demonstration project, and specific implementation steps are as follows.
[0054] As shown in FIG. 2 , the 1000 kV southeastern Shanxi-Nanyang-JingmenUHV AC test and demonstration project starts from a transformer substation in southeastern Shanxi (Changzhi), via a transformer substation in Nanyang, Henan, and terminates at a transformer substation in Jingmen, Hubei. UHV AC line loss theoretical calculation is made by using PSASP developed by China's electricity academy, and various typical operating manners representing a particular year are selected to calculate a power range that covers smaller values to UHV AC rated transmitting powers. The result of the UHV AC line loss theoretical calculation is a correction value after corona loss is considered on the basis of the related program calculation result, reference can be made to the formula (1) for a specific calculation method, the line corona loss used in the calculation is estimated according to related document literature in combination with weather conditions of regions where the UHV AC demonstration project line passes and actual measured values of the corona loss under various weather conditions, the annual mean corona loss power of the UHV AC line is estimated as 14.81 kW/km, the corona loss power of the long southern line is 5.31 MW, the corona loss power of the South Jingmen line is 4.16 MW, and the annual mean corona loss power of the full line is 9.47 MW. The UHV AC transmitting powers and the corresponding theoretical calculation results of the integrated network loss rates are as shown in the table below:
[0000]
TABLE 1
Calculation results of theoretical values of integrated
network loss rates and corresponding transmitting
powers of a UHV AC demonstration project
UHV AC transmitting
Theoretical values of
power (GW)
integrated network loss rates
80
1.98%
250
1.72%
200
1.57%
130
1.49%
190
1.51%
100
1.63%
380
1.98%
400
2.17%
500
2.86%
580
3.10
[0055] A scatter diagram of theoretical calculation values of UHV AC integrated network loss rates and transmitting powers drawn according to the data in Table 1 is as shown in FIG. 3 , it is clear from the figure that the UHV AC integrated network loss rate presents an evident U-shaped quadratic curve relation with the change of the transmitting power, with increase of the UHV AC transmitting power, the integrated network loss rate first decreases and then increases, and curve fitting is carried out by using the least square method, to calculate a function expression of the fitted curve as follows:
[0000] η 1 (P)=1.958-0.004P+1.038×10 −5 P 2
[0056] A variation curve of the UHV AC transmitting powers recorded with hour data on the hour is divided into multiple segments with different time lengths, and a specific dividing method is: the transmitting power of the starting hour on the hour in each time period being an initial power, and when varying amplitude of the transmitting power of the subsequent hour on the hour reaches 10% of the initial power, entering into next time period. An average transmitting power within each time period of the UHV AC system is determined according to the gateway power historical statistical data of the UHV AC demonstration project and the time lengths of respective segments divided, and actual calculation values η actual of the corresponding integrated network loss rates in each time period are calculated according to the formula (2); calculation results are as follows:
[0000]
TABLE 2
Calculation results of actual values of integrated network
loss rates and corresponding transmitting powers after
the main transformer in Nanyang is put into operation
Time period
UHV AC
Actual values of
serial
transmitting
integrated network
number
power (GW)
loss rates
1
182.63
1.504%
2
200.26
1.455%
3
236.39
1.609%
4
217.64
1.458%
5
168.23
1.217%
6
103.89
1.573%
7
153.15
1.385%
8
158.19
1.464%
9
169.51
1.409%
10
86.82
1.408%
11
196.20
1.317%
12
208.13
1.417%
13
231.38
1.596%
14
196.56
1.435%
15
234.67
1.428%
16
201.41
1.343%
17
174.04
1.444%
18
92.33
1.757%
19
87.82
1.826%
20
65.34
2.167%
[0057] A scatter diagram of actual calculation values of UHV AC integrated network loss rates and transmitting powers drawn according to the data in Table 2 is as shown in FIG. 4 (two groups of obviously abnormal data in May and October 2012 are eliminated), and curve fitting is carried out also by using the least square method, to calculate a function expression of the fitted curve as follows:
[0000] η 2 (P)=3.098-0.019P+5.303×10 −5 P 2
[0058] Geometric average correction is performed on the fitted curve of theoretical calculation values by using the fitted curve of the actual calculation values of UHV AC integrated network loss rates and transmitting powers. In consideration of that AC transmitting powers in actual project practice of the UHV AC demonstration project are mostly maintained at 250 GW or below, the fitted curve of the actual calculation values during small-power operation is reltively accurate, while in the case of greater opertion power, the fitted curve of the actual calculation values will genarate a greater error, at this point, the fitted curve of the theoretical calculation values will have a better reference value, and thus the geometric mean of two curves is selected as the value on the correction curve η correct (P); a specific operating method is as follows:
[0059] selecting n+1 points, [P 1 ,η 1 (P 1 )],[P 2 ,η 1 (P 2 )]. . . [P i ,η 1 (P i )], . . . [P n+1 ,η 1 (P n+1 )], from the fitted curve of relations between the theoretical calculation values of UHV AC integrated network loss rates and transmitting powers, wherein P 1 is the minimum transmitting power of the UHV AC line, P n+1 is the maximum transmitting power of the UHV AC line,
[0000]
P
i
=
P
1
+
(
P
n
+
1
-
P
1
)
×
(
i
-
1
)
n
,
[0000] i=1, 2, . . . , n, n+1; then selecting n+1 points with the same abscissa, [P 1 ,η 2 (P 1 )],[P 2 ,η 2 (P 2 )] . . . [P 1 ,η 2 (P i )], . . . [P n+1 ,η 2 (P n+1 )], from the fitted curve of relations between the actual calculation values of UHV AC integrated network loss rates and transmitting powers, through geometric average correction, obtaining points, [P 1 ,√{square root over (η 1 (P 1 )η 2 (P 1 ))}],[P 2 ,√{square root over (η 1 (P 2 )η 2 (P 2 ))}] . . . [P i ,√{square root over (η 1 (P 1 )η 2 (P i )])}, . . . [P n+1 , √{square root over (η 1 (P n+1 )η 2 (P n+1 ))}]; comparison among the fitted curve of theoretical calculation values, the fitted curve of actual calculation values and the correction fitted curve is as shown in FIG. 5 , and the correction curve is fitted to obtain a corresponding function relation:
[0000] η correct ( P )=2.351-0.0095 P+ 2.564×10 −5 P 2
[0060] In the monthly planning and trading settlement process of the UHV AC electricity trading, a more accurate UHV AC planned value of integrated network loss rate can be calculated only by substituting the monthly planned average transmitting power (obtained by the UHV AC monthly planned transaction power value divided by 720 hours) into the correction function relation η correct (P).
[0061] However, in consideration of simple operability, herein, the correction curve is divided into several intervals according to the size of the UHV AC transmitting power: [P 1 ,P 2 ],[P 2 ,P 3 ] . . . [P i ,P i−1 ], . . . , the size of the integrated network loss rate correpsonding to the power interval [P i ,P i+1 ] is calculated through a correction relation, which is set as
[0000]
η
correct
(
P
i
+
P
i
+
1
2
)
,
[0000] and in this way, a series of power intervals and integrated network loss rates corresponding thereto can be obtained.
[0062] The actual transmitting powers of the UHV AC demonstration project at present are basically maintained between 50 to 250 GW, considering that the UHV AC transmitting powers in future may be greater or smaller values, the power range is expanded to 30 GW to 580 GW, and 50 GW is selected as an interval length, to obtain planned values of UHV AC integrated network loss rates shown in Table 3 according to the correction curve function relation.
[0000]
TABLE 3
Query table of planned values of integrated network
loss rates of a UHV AC demonstration project
Power
Integrated
interval
Corresponding
network
(GW)
median
loss rate
[30, 80]
η correct (55)
1.91%
[80, 130]
η correct (105)
1.64%
[130, 180]
η correct (155)
1.49%
[180, 230]
η correct (205)
1.48%
[230, 280]
η correct (255)
1.58%
[280, 330]
η correct (305)
1.83%
[330, 380]
η correct (355)
2.18%
[380, 430]
η correct (405)
2.71%
[430, 480]
η correct (455)
3.33%
[480, 530]
η correct (505)
4.09%
[530, 580]
η correct (555)
4.96%
—
—
—
[0063] In the actual monthly planning and trading settlement of UHV AC electricity trading, a more accurate UHV AC monthly integrated network loss rate can be determined by querying Table 3 only by determining the interval according to the size of the monthly planned average transmitting power.
[0064] The foregoing description of the exemplary embodiments of the present invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the present invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.
[0065] The embodiments were chosen and described in order to explain the principles of the present invention and their practical application so as to enable others skilled in the art to utilize the present invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.
|
The invention relates to a method for determining an integrated network loss rate in the UHV AC cross-regional electricity trading. The method includes fitting a curve relationship between integrated network loss rates and transmitting powers on the basis of theoretical calculations of the UHV AC transmission line loss, using a relational fitted curve between actual values of integrated network loss rates and transmitting powers calculated according to gateway power statistical data to perform geometrical average correction on the original curve, and making planned values of the integrated network loss rates to be closer to the actual values according to a method for determining UHV AC integrated network loss rates according to a correction curve function relation, which greatly increases fairness of the trading settlement. The method is simple and easy to implement with high accuracy, and applicable to planning and trading settlement of regular or real-time UHV AC electricity trading.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to an improved vertically disposed furniture channel, for use in combination with vertical metal studs and horizontal metal channels, having means on the furniture channel for mounting the furniture channel on the horizontal channels with the furniture channel face in the same wall plane as the vertical stud face or with the furniture channel face in the same wall plane as another furniture channel face of a furniture channel mounted over the face of a vertical stud.
An elongate sheet metal furniture channel, having a hat-shaped cross section, has been employed heretofore in a wall framing system consisting of vertical metal studs, mounted to extend from a floor to a ceiling, and horizontal reinforcing metal channels extending through holes in the webs of the vertical studs. The hat shaped furniture channels were mounted vertically with the two opositely directed flanges affixed against the horizontal reinforcing channel.
On some occasions, where heavier furniture is to be supported on the wall, for example, the furniture channels will also be mounted over the faces of the vertical studs. When this was done, the outer faces of the furniture channels mounted over the studs were not in the same plane as the outer faces of the furniture channels mounted against the horizontal channels, resulting in a wall built thereover being not completely flat.
SUMMARY OF THE INVENTION
The present invention is directed to modifying and improving upon the above described hat shaped furniture channels, providing means for mounting the channels on the horizontal reinforcing channels at two optional positions, overcoming the problem of the furniture channel faces being in different planes when some are placed over a stud face.
The invention consists essentially of a furniture channel of a hat-shaped cross section, having, additionally, a small rib located along each flange, with spaced portions of the ribs omitted, whereby the furniture channel can be mounted with either ribbed portions or plain unribbed portions abutting the horizontal channels, providing optional positions for the furniture channels.
It is an object of the invention to provide an improved furniture channel having two optional mounting positions.
It is a further object to provide a method of mounting furniture channels which permits all framework elements on which wallboard is mounted to be in the same plane whether a furniture channel is mounted over a stud face or not.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a strip of furniture channel embodying the present invention.
FIG. 2 is an isometric view of a partition wall, portions being broken away, having the furniture channels of FIG. 1 included therein, in accordance with the invention.
FIG. 3 is a horizontal sectional view of the partition wall of FIG. 2, taken along line 3--3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown an elongate sheet metal furniture channel 10, formed from, preferably, 20 gauge galvanized steel, and formed as a one-piece unit, including a central face section 12, a pair of webs 14, 14 extending perpendicularly rearwardly, one from each lateral edge 16, 16 of face section 12 and a pair of flanges 18, 18 extending outwardly from the rearward edge of each web 14, 14. The two flanges 18, 18 lie in a common plane, parallel and spaced from the plane of face section 12.
Each flange 18 includes a rearwardly protruding arcuate shaped, elongate bead portion 20, preferably at the inner edge of the flange 18 where flange 18 adjoins a web 14. The bead portion 20 is intermittent, with gaps 22, where short sections of the bead portion have been removed, located at equally spaced apart positions of 29 inches, center to center.
Referring to FIGS. 2 and 3 a partition wall 30 is shown, having a first side 32 and a second side 34. Wall 30 includes vertical metal studs 36 mounted between a floor runner 38 and a ceiling runner 40. Each stud 36 has a plurality of openings 42 in the web 44, which are located in equally spaced apart positions of 29 inches, center to center.
Upwardly opening elongate metal reinforcing channels 46, having a U-shaped cross-section, are located extending horizontally through a plurality of openings 42 in studs 36, resting on the bottoms of the openings 42, with the topmost reinforcing channel 46 located 20 inches from the ceiling runner 40.
A plurality of vertically extending furniture channels 10 are screw attached to each side of the plurality of horizontal reinforcing channels 46.
On the first side 32 of wall 30 the furniture channels 10 are located only at spaced positions in between studs 36. In order for the face section 12 of each furniture channel 10 to be in the same plane as the face section 48 of each stud 36, the furniture channel 10 is located with the gaps 22 immediately against the reinforcing channels 46.
On the second side 34 of wall 30, furniture channels are located at spaced positions in between studs 36 and also over each stud face section 48. These furniture channels 10 on the second side 34 are all located with the gaps 22 in between reinforcing channels 46, whereby the raised bead portions 20 rest immediately against the reinforcing channels 46. The presence of the raised bead portions 20 against the reinforcing channels 46 causes the furniture channnels 10 to all extend relatively further out from the reinforcinig channels 46 a distance which is sufficient for the furniture channels 10 located over studs 36 to be mounted firmly against the reinforcing channels, without interference from the presence of the stud 36. Thus, all the face sections 12 of the furniture channels 10 on the second side 34 are also in a common plane.
In the preferred embodiment, the stud 36 has a face section 48 which is about 11/4 inch to 13/8 inch wide and a stud depth, one face section to the opposite face section, of 21/2 inches. The reinforcing channel 46 is centered between the two opposite stud face sections and is 3/4 inch in height and 11/2 inches in depth. The furniture channel 10 has a face section 12 which is 2 inches wide, flanges 18, 18 which have a width of 1/2 inch, and webs 14, 14 which have a depth such that the depth of the furniture channel 10 from the plane of the inner surface of the flanges 18, 18 to the plane of the outer sruface of the face section 12 is 1/2 inch, the same as the distance from the plane of the reinforcing channel 46 to the plane of the stud face section 48.
The height of the bead portion 20 may be any amount equal to or greater than the thickness of the metal of the furniture channel face section 12, which is preferably a 20 gauge galvanized steel, or 0.036 inch. A 1/16 inch high bead provides substantial clearance between the furniture channel 10 and the stud face section 48.
As shown in broken away sections, gypsum wallboard 50 is screw attached to studs 36, with screws extending through both the furniture channel face section 12 and the stud face section 48 on the second side 34 of wall 30.
Furniture, such as shelves, desks, or benches are then hung from the walls with attaching means affixed by known means to the furniture channels located behind the wallboard 50.
Having compiled a detailed disclosure of the preferred embodiments of my invention, so that those skilled in the art may practice the same, I contemplate that variations may be made without departing from the essence of the invention.
|
A furniture channel for vertical disposition against horizontal framing members, with an intermittent raised bead on the furniture channel inner surface for selective, optional positioning, against the horizontal framing members, for obtaining the desired spacing of the furniture channel faces from the framing members.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority benefit of China application No. 200610088817.4 filed on Jul. 19, 2006, the contents of which is hereby incorporated by reference in its entirety.
BACKGROUND
1. Field of the Invention
The present invention relates to a process and an apparatus for synthesizing inorganic metal oxide nanopowders and metal nanoparticles (colloid). The nanoparticles can be used as precursors to prepare nanocatalysts and nanomaterials.
2. Description of Related Art
Nanoparticle is accumulation or cluster of atoms about 1 to 100 nm length and increasingly important material used in various areas ranging from nano-technology, non-line optics, diode laser, smart sensor, information store, gene sequencing to catalysis. During the past decades, a lot of methods have been developed for preparing nanoparticles. For example, Microwave/sonication-assisted Coprecipitation, Sol-Gel Process, Hydrothermal/Solvothermal methods, Templated Syntheses, Revise Microemulsion, Hydrolyzation, and Spray Pyrolysis have been used to synthesize metal oxide nanopowders; Vapor Deposition, Mechanical Attrition, Laser Ablation, Electrochemical Reduction, Radiolysis Reduction, Chemical reduction, and Alcohol Reduction have been employed to prepare metal nanoparticles. However, some methods mentioned above require very expensive equipments, some of them lack the ability in the precise control in the generation and growth of nanocrystals, resulting in the wide distribution of nanoparticle size. In addition, some chemical methods often involve reduction of the relevant metal salts or decomposition of organometallic precursor in the presence of a suitable surfactant that is expensive.
In order to control precisely the generation rate and growth of nanocrystal for preparing nanoparticles with narrow size distribution, several new apparatuses and processes have been developed recently for the synthesis of nanoparticles, especially for the synthesis of metal nanoparticle.
Microfluidic system has been proven to be an idea medium for nanoparticles production because both mass and thermal transfer are rapid and then the nucleation of solute molecules and growth of nanocrystal can be precisely controlled (Nature, 442, 27 Jul. 2006). Wagner used microchannel reactor to generate Au nanoparticles with the size of 11.7 nm±0.9 nm (Chemical Engineering Journal 101 (2004) 251-260). Although microfluidic method can be used to produce nanoparticles with narrow size distribution and get great attention, it is insurmountable difficult to use it to prepare metal nanoparticles in large-scale.
In summary, the available methods of preparing inorganic metal oxide and metal nanoparticles, especially for metal nanoparticles, are very costly and difficult to produce nanoparticles with narrow size distribution in large-scale.
Accordingly, there remains a great need for fabricating methods of inorganic metal oxide nanopowders and metal nanoparticles with narrow size distribution. There also remains a need for methods to control growth of inorganic metal oxide nanopowders and metal nanoparticles in the process of mass-production.
SUMMARY OF THE INVENTION
The present invention provides an approach to control the generation and growth of nanocrystal with a membrane diffusion method and related apparatuses to produce inorganic oxide nanopowders and metal nanoparticles. With this method, the size and size distribution of inorganic oxide nanopowders and metal nanoparticles can be tuned. It overcomes the shortcomings possessed by the common chemical and physical method of preparing nanoparticles.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and/or other aspects and advantages of the present apparatus will become apparent and the invention will be better understood by reference to the following description of the embodiments thereof taken in conjunction with the accompanying drawings.
FIG. 1 is a schematic view of an apparatus referring to batch reactor for preparing inorganic metal oxide nanopowders and metal nanoparticles in accordance with an embodiment of the present invention.
FIG. 2 is a cross-section view of the batch reactor with ceramic or polymer micro-membrane tube unit installed inside of it.
FIG. 3 is a schematic view of an apparatus referring to a tubal reactor for mass-preparing inorganic metal oxide nanopowders and metal nanoparticles in accordance with an embodiment of the present invention.
FIG. 4 is a cross-section view of the tubal reactor used for mass-preparing nanoparticles, inside of which a ceramic or polymer micro-membrane tube unit is installed.
FIG. 5 and FIG. 6 are a schematic view of an apparatus referring to a tubal reactor for preparing inorganic metal oxide nanopowders and metal nanoparticles in accordance with an embodiment of the present invention.
FIG. 7 is a cross-section view of an apparatus referring to the tubal reactor for preparing inorganic metal oxide nanopowders and metal nanoparticles in accordance with an embodiment of the present invention.
FIG. 8 is a schematic view of an apparatus referring to assembled tubal reactors in parallel connection for mass production of inorganic metal oxide nanopowders and metal nanoparticles.
FIG. 9 is a SEM (Scanning electron microscope) image of the Ce 0.6 Zr 0.4 O 2 nanomaterial that was prepared by the method described in the invention.
FIG. 10 is a SEM image of the Ce 0.6 Zr 0.4 O 2 nanomaterial that was prepared by common coprecipitation method.
FIG. 11 is a TEM (transmission electron microscope) image of Ag nanoparticles produced according to the batch reactor used in the present invention.
FIG. 12 is a TEM image of Ag nanoparticles produced according to normal chemical reduction method, i.e. the Ag nanoparticles was generated by dropping the NaBH 4 solution into a mixture solution of AgNO 3 and Polyvinyl Pyrrolidone (PVP).
FIG. 13 is a TEM image of Au nanoparticles produced according to the batch reactor used in the present invention.
FIG. 14 is a TEM image of AuRh alloy nanoparticles produced according to the batch reactor used in the present invention.
FIG. 15 a TEM (transmission electron microscope) image of Ag nanoparticles produced according to the tubal reactor used in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made to the drawings to describe in detail of the apparatus for producing inorganic metal oxide nanopowders and metal nanoparticles according to the present invention.
Referring to FIG. 1 and FIG. 2 , an apparatus 100 for producing inorganic oxide nanopowder and metal nanoparticles according to the embodiment of the present invention is shown. The apparatus 100 includes a stirrer 1 , a batch reactor 2 , a micro-membrane tube unit 3 , an ultrasonic generator 4 , a container 5 and a measuring pump 6 . The micro-membrane tube unit 3 is installed in the batch reactor 2 . The micro-membrane tube unit 3 is composed of a tube holder 9 made of Teflon and a Polyethersulfone membrane tube that is fixed on the tube holder 9 . As an example, the inner and outer diameters as well as the length of a specific Polyethersulfone membrane tube used in one embodiment of this invention are 0.7, 1.3 and 4000 mm, respectively, with the tube wall thickness of 0.3 mm and micro-hole diameter of 0.04 μm on the tube wall. One end of the Polyethersulfone membrane tube is sealed, for example, by epoxy resin and the other is open as inlet 7 that is connected with the measuring pump 6 by a tube line. An oar 8 is installed at the end of the stirrer axis that reaches into the space surrounded by the micro-membrane tube unit 3 . As the apparatus 100 is employed to synthesize inorganic metal oxides nanopowders and metal nanoparticles, the batch reactor 2 is set up with the ultrasonic generator 4 . The measuring pump 6 is linked with container 5 with a tube line.
Referring to FIG. 3 and FIG. 4 , an apparatus 200 with a tubal reactor 2 for mass-production of inorganic oxide nanopowders and metal nanoparticles according to the embodiment of the present invention is shown. The apparatus 200 includes a stirrer 1 , a tubal reactor 2 , a micro-membrane tube unit 3 which can be made of ceramic or polymer, or other suitable materials, an ultrasonic generator 4 , a container 5 and a measuring pump 6 . The tubal reactor 2 is connected with the ultrasonic generator 4 and has one outlet 11 at one end and two inlets 10 at the other end of the tubal reactor 2 , one inlet 10 is connected to the measuring pump 6 . The micro-membrane tube unit 3 with a stirrer 1 is installed inside of the tubal reactor 2 . The micro-membrane tubes 3 are fixed, for example by epoxy resin, on two seal caps 13 that are used to seal the reactor 2 . One end of the micro-membrane tube is also sealed by the seal cap 13 and the other is open as an inlet 7 that is linked to inlet 10 of the tubal reactor 2 via a cavity 12 and to the measuring pump 6 via the inlet 10 . The measuring pump 6 is connected with container 5 by a tube line.
Referring to FIG. 5 and FIG. 6 , an apparatus 300 for producing inorganic oxide nanopowder and metal nanoparticles according to the embodiment of the present invention is shown. The apparatus 300 includes a tubal reactor 2 , a micro-membrane tube unit 3 , an ultrasonic generator 4 , two containers 5 , a measuring pump 6 and a peristaltic pump 14 . The tubal reactor 2 has two inlets 10 and one outlet 11 , one of the inlets 10 is connected with the first container 5 and the other inlet 10 is connected to the measuring pump 6 that is linked to the second container 5 . The outlet 11 is linked with a peristaltic pump 14 that is also connected with container 5 . The peristaltic pump 14 , first container 5 and tubal reactor 2 form a loop-way. The micro-membrane tubes 3 are fixed, for example by epoxy resin, on two sealed caps 13 that are used to seal the butal reactor 2 . One end of the micro-membrane tube is also sealed by the seal cap 13 and the other is open as an inlet 7 that is linked to inlet 10 of the tubal reactor 2 via a cavity 12 and to the measuring pump 6 via the inlet 10 . The measuring pump is also connected with the second container 5 by a tube line.
Referring to FIG. 7 , the micro-membrane tube unit 3 comprises micro-membrane tubes that are made of ceramic or polymer materials and located at a circle line around the dummy central axis of the tubal reactor 2 .
Referring to FIG. 4 and FIG. 7 , the micro-membrane tube unit 3 comprises micro-membrane tubes that are made of ceramic or polymer materials. The micro-holes are formed on walls of the micro-membrane tubes, and the size of the micro-holes on the walls of the micro-membrane tubes is ranged from 0.03 to 0.3 μm. One example of the ceramic micro-membrane tubes is that made of α-Al 2 O 3 . The inner and outer diameters as well as the length of a specific ceramic micro-membrane tube used in one embodiment of this invention are 3, 4 and 200 mm, respectively, with the tube wall thickness of 0.5 mm and micro-hole diameter of 0.04 μm. The polymer micro-membrane tubes can be made of a polymer material selected from the group consisting of polypropylene, polyethermide, polysulfone, Polyethersulfone and polyvinylidene fluoride.
Referring to FIG. 8 , as the butal reactor 2 being employed, an advantage of the invention is that the yield of inorganic oxide nanopowders and metal nanoparticles can be enhanced simply by increasing the number of butal reactors 2 without the negative effect caused by expanding the volume of reactor.
Referring to FIG. 1 , a method of preparing inorganic metal oxide nanopowders and metal nanoparticles is the process described as the following:
(I) The desired metal precursor(s) is (are) dissolved in distilled water in the presence or absence of a protective agent. The solution of the desired metal precursor(s) is transferred into the batch reactor 2 , the solution of a reductant/precipitator is transferred into the container 5 ; (II) The solution of the precipitator or reductant stored in container 5 is injected into the lumens of micro-membrane tube unit 3 via the measuring pump 6 from the inlet 7 of the micro-membrane tube unit 3 at a desired flow rate, temperature, stirring speed and a desired supersonic frequency, and then diffuses into inside of the batch reactor 2 via the micro-holes distributed on the wall of the micro-membrane tube unit 3 . In reactor 2 , which contains a solution of a metal precursor with or without protective agent, the precipitation or reduction occurs. (III) As the invention method is used to synthesize inorganic metal oxides, the precipitation reaction is carried out for 2-8 hours, and then the precipitate is filtered, washed with distilled water, dried in air and calcined at desired temperature for 2-8 hours, giving the product of inorganic metal oxides nanoparticles. (IV) When the inventive method is used to prepare metal nanoparticles, the reduction reaction is not stopped until 5-20 times amount of reductant as the metal ion amount is injected into the batch reactor 2 . The resulting liquid is a colloid of metal nanoparticles with narrow metal particle size distribution.
Referring to FIG. 3 and FIG. 4 , a method of preparing inorganic metal oxide nanopowders and metal nanoparticles in mass scale is the process described as the following:
(I) The desired metal precursor(s) is (are) dissolved in distilled water in the presence or absence of a protective agent. The solution flows via the inlet 10 that is linked with measuring pump 6 into the reactor 2 that is used for mass-preparing inorganic metal oxide nanopowers and metal nanoparticles; the solution of reductant/precipitator is transferred into the container 5 ; (II) The solution of precipitator/reductant driven by a measuring pump 6 is injected through the inlet 9 and inlet 7 into the lumens of micro-membrane tube unit 3 , at a desired flow rate, temperature, stirring speed and a desired supersonic frequency, and then diffuses into inside of the tubal reactor 2 via the micro-holes distributed on the wall of the micro-membrane tube unit 3 . The reaction occurs immediately. (III) As the invention method is used to synthesize inorganic metal oxides, the ration time in the tubal reactor for the reactive solution is from 2 to 8 hours, giving the products flowed out from outlet 11 . And then the product (metal oxide precursor nanoparticles) are filtered, washed with distilled water, dried in air and calcined at desired temperature for 2-8 hours, giving inorganic metal oxides nanoparticles. (IV) When the inventive method is used to prepare metal nanoparticles, the reactive solution flows out from the outlet 11 , at which the concentration of reductant is 5-20 times as that of metal components injected into the tubal reactor 2 , giving a colloid of metal nanoparticles with narrow metal particle size distribution.
Referring to FIG. 5 and FIG. 6 , the tubal reactor 2 and other related equipments can be set up according to another way. The peristaltic pump 14 , container 5 and tubal reactor 2 form a loop. An aqueous solution of metal precursor(s) with or without protective agent is recycled through the tubal reactor 2 and container 5 , driven by a peristaltic pump 14 .
In an embodiment of the invention, for the batch or tubal reactor 2 , flow rate of the solution driven by measuring pump 6 is from 0.2 to 100 ml/min; the rotate speed of the stirrer is from 100 to 200 r/min; the supersonic frequency is from 60 to 120 KHz.
The approach of preparing inorganic metal oxide nano-powders and metal nanoparticles can be accomplished in another way: solution of precipitator or reductant is transferred into the reactor 2 . Correspondingly, the solution of metal salts is kept in container 5 and injected by measuring pump 6 into the solution of precipitator or reductant via the micro-holes distributed on the wall of the micro-membrane tube unit 3 .
In another embodiment of the invention, the solution of the metal precursor and protective agent is obtained by dissolving inorganic or organic metal salts of rare earth metals, alkaline-earth metals and transition group metals with protective agent in distilled water.
In a further embodiment the precipitation reagent are selected form the group consisting of NH 4 OH, NaOH and oxalic acid.
In a further embodiment the reductants are selected from the group consisting of NaBH 4 , N 2 H 4 .H 2 O, N 2 H 4 , formaldehyde, Oxalic acid and Ascorbic acid.
The inorganic metal oxide nanopowders or metal nanoparticles prepared by this invention is small in size and uniform in narrow size distribution with low cost and ability in controlling the generation and growth of nanoparticles in the process of crystallization
EXAMPLE 1
In this experiment, 51.2 g of Ce(NO 3 ) 3 .6H 2 O and 14.6 g of ZrONO 4 were dissolved in 300 ml distilled water and transferred into the batch reactor 2 . The batch reactor 2 was dipped in an ultrasonic generator 4 at frequency of 60 KHz and temperature of 60° C. The rotate speed of the stirrer 1 is 100 r/min. A desired amount of NH 4 OH solution was injected into the lumens of membrane micro-tube unit 3 at a constant rate of 0.2 ml/min by a measuring pump 6 and then diffused into the mixture solution of Ce(NO 3 ) 3 .6H 2 O and ZrONO 4 via the micro-holes on the wall of membrane micro-tube unit 3 until the pH=10 of the solution in the batch reactor 2 . The precipitation of metal oxide precursor (hydroxid) occurred, yielding a buff color precipitate. The precipitate was filtered, washed with distilled water, and dried in air at 110° C. for 10 hours, and then calcinated at 550° C. for 4 hours, giving the products of Ce 0.6 Zr 0.4 O 2 nanoparticles with particle size of 10 nm and specific surface area of 108 m 2 /g ( FIG. 9 ). The Ce 0.6 Zr 0.4 O 2 nanoparticles prepared by the method described in the invention were smaller in size with narrow size distribution than the Ce 0.6 Zr 0.4 O 2 solid solution synthesized by common coprecipitate method ( FIG. 10 ). The oxygen storage determined by H 2 —O 2 titration of the former was larger (0.757 mmol/g) than that (0.357 mmol/g) of the later.
EXAMPLE 2
In this experiment, 0.16 g of AgNO 3 and 60 g of Polyvinyl Pyrrolidone (PVP, molecular weight is 30000) were dissolved in 300 ml distilled water and transferred into the batch reactor 2 . 0.53 g of NaBH 4 was dissolved in 30 ml distilled water and transferred into the container 5 . The batch reactor 2 was dipped in an ultrasonic bath 4 at frequency of 120 KHz and the temperature of 60° C. At same time, NaBH 4 solution was injected into the lumens of membrane micro-tube unit 3 at a constant rate of 1.2 ml/min by a measuring pump 6 and then diffused into the mixture solution of AgNO 3 and PVP via the micro-holes on the wall of membrane micro-tube unit 3 . The rotate speed of the stirrer 1 is 200 r/min. The Ag nanoparticles with size of 5-8 nm ( FIG. 11 ) were produced with uniform size distribution, which is smaller than that produced by common chemical reduction of AgNO 3 ( FIG. 12 )
EXAMPLE 3
In this experiment, 0.836 g of HAuCl 4 and 24 g of Polyvinyl Pyrrolidone (PVP, molecular weight is 30000) were dissolved in 500 ml distilled water, and then transferred into the batch reactor 2 . 1.16 g of NaBH 4 was dissolved in 50 ml distilled water and transferred into the container 5 . The batch reactor 2 was dipped in an ultrasonic generator (100 KHz) 4 at the temperature of 50° C. At same time, NaBH 4 solution was injected into the lumens of membrane micro-tube unit 3 at a constant rate of 1 ml/min by a measuring pump 6 and then diffused into the mixture solution of AgNO 3 and PVP via the micro-holes on the wall of membrane micro-tube unit 3 , resulting the Au 3+ reduction occurred. The rotate speed of the stirrer 1 is 150 r/min. In the end of this process, the color of the solution turned to be wine-reddish color, giving the Au nanoparticles with quite narrow uniform size distribution. The average size of Au nanoparticles was 3.5 nm ( FIG. 13 ).
EXAMPLE 4
In this experiment 8.8 g of NaBH 4 was dissolved in 120 ml distilled water. 3.18 g of HAuCl 4 , 3.75 g of RhCl 3 and 139 g of Polyvinyl Pyrrolidone (PVP, molecular weight is 30000) were dissolved in 1000 ml distilled water. The solutions of NaBH 4 and metal salts (HAuCl 4 and RhCl 3 ) with PVP were transferred into the container 5 and batch reactor 2 , respectively. The batch reactor 2 was dipped in an ultrasonic bath at frequency of 80 KHz and the temperature of 40° C. At same time, NaBH 4 solution was injected into the lumens of membrane micro-tube unit 3 at a constant rate of 3.5 ml/min by a measuring pump 6 and then diffused into the mixture solution of metal salts and PVP via the micro-holes on the wall of membrane micro-tube unit 3 , resulting the Au 3+ and Rh 3+ reduction occurred. The rotate speed of the stirrer 1 is 100 r/min. In the end of this process, the color of the solution turned to be brown-reddish color, giving the AuRh (Au:Rh=1:1) alloy nanoparticles with quite narrow uniform size distribution. The average size of AuRh (Au:Rh=1:1) alloy nanoparticles was 2 nm ( FIG. 14 ).
EXAMPLE 5
In this experiment, 1.0 g of NaBH 4 was dissolved in 50 ml DI water (indicated as solution A). 0.2 g of AgNO 3 and 1.2 g of Polyvinyl Pyrrolidone (PVP, molecular weight is 30000) were dissolved in 200 ml distilled water (indicated as solution B). The solution A and B were transferred into the two containers 5 respectively. And then, solution B was recycled through the butal reactor 2 and the container 5 , in which the solution B was stored, at flow rate of 600 ml/min driven by the peristaltic pump 14 . The tubal reactor 2 was dipped in an ultrasonic generator 4 at frequency of 100 KHz and temperature of 40° C. At same time, solution A was inject into the lumens of membrane micro-tube unit 3 at a constant rate of 7 ml min −1 by a measuring pump 6 and diffused into solution B via the micro-holes on the wall of membrane micro-tube unit 3 , resulting the Ag + reduction occurred. In the end of this synthesis process, the color of the solution turned to be reddish, giving the Ag nanoparticles with quite narrow uniform size distribution. The average size of Ag nanoparticles was 6.5 nm ( FIG. 15 ).
|
The present invention provides an approach to control the generation and grow of nanocrystal with membrane diffusion method and related apparatuses to produce inorganic oxide nanopowders and metal nanoparticles. With this method, the size and size distribution of inorganic oxide nanopowders and metal nanoparticles can be tuned. It overcomes the shortcomings possessed by the common chemical and physical method of preparing nanoparticles.
| 1
|
FIELD OF THE INVENTION
The present invention relates to the extrusion of materials in the form of continuous wires by the forced passage of the extrusion material through the orifice of a die. More specifically, it relates to a novel extrusion process wherein the extrusion material is continuously removed from the surface of the material. It also relates to a device for implementing the invention and to the applications of this process, more particularly, for the manufacture of very narrow metal wires.
BACKGROUND
Various techniques have long been used for the extrusion of different types of materials. For example, in the manufacture of fine metal wires having diameters ranging between a few thousandths and a few tenths of a millimeter from wires having diameters of one or more millimeters, the raw material is passed through a set of dies of successively decreasing diameters until the desired wire diameter is obtained. In the case of copper drawing, for example, a machine designed to produce a wire having a diameter of 0.02 mm from a starting wire having a diameter of 0.1 mm, comprises at least twenty dies. Apart from the high cost of producing machines of this type, it must be appreciated that the preliminary manual operations for successively inserting the specially tapered end of the wire into each die in the series until sufficient lengths for winding on the winches are obtained, are extremely long and tedious. In addition, the diameters of the successive dies must be very exact: for example, the permissible tolerance in the case of a wire having a diameter of 0.01 - 0.02 mm is 0.001 mm. Furthermore, friction affecting the metal inside each die frequently causes breaks in the wire upstream of the die which result in loss of time and material.
OBJECT AND SUMMARY OF THE INVENTION
The present invention was designed to obviate the above disadvantages by replacing the wire drawing process which is currently used by a novel extrusion process which is extremely simple to implement and which, by virtue of the very simple apparatus employed, makes it possible to reduce the cost of conventional wire drawing machines by a factor of a number of units.
Various processes for extruding fine wires have obviously been previously proposed, particularly those employing so-called hydrostatic drawing techniques, but none of these processes make it possible to produce an extremely fine wire of indefinite length (having a diameter between one and a few tenths or hundredths of a millimeter), at a high rate (on the order of several tens of meters per second) which is generally essential for the manufacturing process to be economically viable.
The invention provides a solution to this technical problem in that it proposes a process and a device for directly obtaining a fine wire of indefinite length by means of a single drawing tool by removing the extrusion material solely from the surface of the starting material or billet which may have infinitely variable dimensions.
The novel process according to the invention is characterized essentially in that the material to be extruded is advanced in front of the die in order to maintain a localized mechanical pressure upstream of, and in the vicinity of the die orifice, and in that this material is removed in a regular manner exclusively from the surface layer of a material of infinitely variable shape and dimensions; the die directly supplying, in a single step, a continuous wire of the desired gauge and of indefinite length.
According to a main feature, the effect of the localized pressure maintained in the material by its advancement movement in front of the die, the removal of the material exclusively from the surface layer of a starting material of infinitely variable shape and dimensions and the extrusion of an endless wire through the die orifice, are simultaneously and directly achieved by means of a single unitary tool comprising the die orifice.
In the process, the material which is fed to the machine and which is advanced or rotated at high speed in front of and towards the drawing tool, may take various forms. For example, it may consist of a solid cylindrical element or a cylindrical element comprising a surface layer consisting of an extrusion material. In the latter case, the cylinder is rotated and the die is displaced on the surface of the cylinder, the material then being removed along a helicoidal path on the surface. The billet can also possess an elongated form, for example, a wire, rod, bar, strip, etc., or it can possess a flat shape, for example, a plate, sheet, etc. In the latter case, the material is removed either along one or more generatrices or along any particular path, the die remaining stationary.
According to a variant of the above process, the billet remains stationary and the die is displaced about or along the billet.
A device according to the invention, which is designed to carry out the above operations, comprises the following elements in addition to the conventional means for rotating or advancing the material to be extruded:
a) a unitary drawing tool which is generally formed from a diamond and is applied to the surface of the material. The drawing tool comprises the following elements which are listed as they occur from upstream to downstream in the direction of movement of the material:
a smooth front face designed to slide on the material and comprising an engagement incline for engagement with the material, at least one calibrated orifice having a corresponding transversal section to that of the wire to be produced and the axis of which is substantially orthogonal to the front face and, directly downstream of the calibrated orifice, at least one projecting nose or lip designed to penetrate the material to be extruded and to push it back in front of the same and force it to flow into the orifice.
b) conventional means for winding the narrow wire product onto spools after it passes through a mechanical tension accumulator-regulator.
During the extrusion operation, the front face of the tool, which comprises an incline for engagement with the billet, is firmly applied by mechanical pressure to the surface of the billet and the latter, which is being advanced as described above, slides on the front face in one direction such that the surface of the billet encounters the lip or nose directly downstream of the calibrated orifice. The application pressure is maintained at a sufficient level to enable the lip to completely penetrate the billet. During the relative sliding movement between the tool and the billet, the lip pushes back or displaces the material in front of it. This displaced material tends to produce a swelling on the surface in the proximity of the lip, more particularly, upstream of the latter, but the pressure exerted in this zone by the front face of the tool is opposed to this swelling. Thus the material is subjected to very high pressure in the zone situated in the vicinity of the calibrated die orifice and, when this pressure reaches a sufficient level, the material flows through the orifice in the form of a continuous wire.
The tool is generally made of a very hard, resistant material such as a diamond, particularly when metal wires are being extruded. This also applies to the conventional dies of drawing machines. The lip on the tool which is used to remove the material by penetrating the surface of the billet at high speed constitutes an integral part of the die and may comprise any suitable configuration which will enable it to slice the surface of a hard billet, for example, a metal, over a long period of time without excessive wear.
The die may comprise a single extrusion orifice and, downstream of and in the vicinity of the latter, a single projecting lip on the front face pressing on the billet. However, according to a variant, the tool may be designed with a plurality of calibrated orifices, either disposed immediately upstream of a projecting lip, or distributed between a plurality of lips, so as to simultaneously produce a plurality of wires having the same diameter or different diameters.
Owing to the fact that in the process according to the invention, the material, for example, the metal, is extruded solely from the surface of the billet, the latter cannot be completely converted into wire a priori. To obviate this disadvantage, which, in certain cases, could render the operation less economically viable, it is possible to increase the proportion of convertible billet, either by using a plurality of drawing tools on a single billet or by subjecting a single billet to a plurality of successive extrusion operations, or by combining the two above methods.
As indicated above, the shape and dimensions of the material constituting the billet are infinitely variable as is also the section of the wire which is produced, depending on the form preselected for the die orifice. Accordingly, in the extrusion of copper, for example, it is possible to directly obtain, in a single step, a copper wire having a diameter of 0.02 mm by using as billet, either a wire having a circular section of approximately 0.15 mm in diameter, or a strip or wire having a circular section flattened by crushing, or a cylindrical rod of any given diameter, or a sheet or plate or any other form of starting material.
A particularly advantageous feature of the process according to the invention consists in that as the wire is extruded from the surface of the billet, it is possible to precoat any type of support consisting of a hard material, such as ceramic, metal carbide, etc., with a layer of extrusion material produced by electrolysis, by sublimation under vacuum, or by any other type of process; the wire then being extruded solely from the thickness of this coating. This method makes it possible to economically produce an extremely pure wire possessing excellent metallurgical properties and comprising a minimum of faults capable of producing breaks. Thus, according to a particular application of the invention, it is possible to continuously produce metal wires, for example, copper wires, from a billet consisting of a plurality of cylinders made of a hard material and mounted for rotation on a rotary element for the purpose of successively subjecting them to the following operations: coppering, rinsing, drying, extrusion of the wire, scouring, rinsing, drying, decoppering and recoppering, etc., in a continuous cycle. It is obviously possible to apply the metal coating to the surface of the hard support by other methods than electrolysis, for example, by means of chemical deposition processes, by metallization under vacuum or by any other conventional method.
According to another mode of implementing the process according to the invention, when the billet consists of a wire, for example a metal wire having a relatively large diameter, it is particularly advantageous to cause this wire, which is being driven at high speed on a wind-on wind-off unit, to be continuously advanced in front of the drawing tool by passing it over a rotary cylinder made of hard material and disposed opposite the drawing tool. According to an improvement of this mode, this cylinder advantageously comprises on its surface, a circular groove or channel acting as a guide for the wire. At the output of the die or dies, the wire is rewound under sufficient tension to ensure that the combined effect of this tension and the contact with the rotating cylinder causes the wire to be advanced at a regular rate.
BRIEF DESCRIPTION OF DRAWINGS
Other objects, features and advantages of the present invention will be made apparent in the following detailed description of a drawing tool having the above-described features (FIGS. 1A-1D) and of various modes of implementing the same which are represented briefly in FIGS. 2 and 3 and which will be described hereinafter. More particularly:
FIGS. 1A and 1B represent, in sections a--a and b--b, sections disposed at 90° from one another, an implement in accordance with the present invention;
FIGS. 1C and 1D represent, in sections c--c and d--d, sections disposed at 90° from one another, another embodiment of an implement in accordance with the present invention;
FIG. 2 is a schematic view of an extrusion apparatus utilizing an implement according to the present invention; and
FIG. 3 is a schematic view of another embodiment of an extrusion apparatus utilizing an implement according to the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring now to FIGS. 1A and 1B, the drawing tool 5 comprises essentially: a smooth front face 1 comprising a gentle incline for engagement with the supply billet, a calibrated orifice 2, the axis of which is substantially orthogonal with respect to the front face and a lip or nose 3 which projects from the front face and which is situated in the immediate vicinity of the orifice 2. To carry out the extrusion process, the billet 4 is rotated or advanced in front of the tool by the firm application of the front face 1 on the surface of billet 4. During its displacement according to the arrow F, the surface of the billet 4, for example, a metal billet, encounters the lip 3 directly downstream of the orifice 2. The application pressure of front face 1 on the surface of billet 4 must be sufficient for the lip 3 to penetrate fully into the billet 4. During the relative sliding movement between the tool and the billet, the lip pushes back the metal in front of the same. This metal, which forms a surface deformation, against which the application pressure of the front face 1 is exerted, is exposed to very high pressure in the zone at the input of the calibrated orifice 2. When this pressure reaches a sufficent level, the metal flows through oriface 2 in the form of a continuous wire 6.
According to a variant represented in FIGS. 1C and 1D, the upstream face of the lip 3 of the tool 5 may be worked simultaneously with the front face 1 and in extension of the latter. In this case, the engagement incline must be sufficiently large to provide the lip 3 with adequate penetration depth. This engagement incline is designated in FIG. 1D by the angle alpha. However, this is a simplified representation as the front face 1 is not necessarily flat.
According to the above-mentioned variant, it is the drawing tool which is capable of being displaced about or along the billet which remains stationary.
In order to cool and improve the operating conditions of the drawing tool, it may obviously be necessary to carry out a lubrication operation using any conventional means.
OPERATING EXAMPLES
By using Lp to designate the length of the path travelled by the drawing plate on the surface of the billet, and Lf to designate the corresponding length of the wire produced, the linear production output can be defined as R = Lf/Lp. This output is a function of a number of parameters such as the shape and dimensions of the drawing tool, the application pressure of this tool, the nature and section of the extruded wire, the sliding rate relative to the front face 1 on the surface of the billet (FIG. 1) lubrication, etc.
In practice, when the process according to the invention is implemented, R is often comprised between 0.5 and 2 but it can also attain much higher values. In the following examples, which relate to the production of a copper wire having a circular section of 0.02 mm in diameter and in which a diamond drawing tool is used, R will be equal to 1.
Example 1
This example illustrates a method of extruding copper wire from an electrolytic copper surface layer deposited on a cylindrical steel support and it refers to the simplified diagram in FIG. 2.
The support is a ground steel cylinder 7 having a circumference of 1m and length of 1.5m. It is coated with a layer of electrolytic copper 8, 0.03 - 0.06 mm in thickness, and then mounted on a special machine (not represented) operating in the manner of a lathe, the cylinder rotating in the direction of the arrow 9.
The drawing tool 10 (the structure of which is identical to those represented in FIG. 1) moves along the cylinder in the direction of the arrow 11. It removes a copper wire 12 from the thickness of the deposit 8 by following a helicoidal path 13 on the cylinder. The wire 12, which is produced, passes over a conventional mechanical tension accumulator - regulator 14 before being wound on the receiving spool 15.
The drawing tool advances by 0.15 mm per rotation and the total path covered by this tool is 10,000 m. When R = 1, the length of the wire produced is also 10,000 m, which corresponds to about 30 g. copper wire having a diameter of 0.02 mm. The duration of the operation was about 10 minutes.
After the copper supply constituted by the electrolytic deposit 8 has been used up, the cylinder is removed from the machine. It is then scoured, rinsed, dried, electrolytically decoppered, recoppered, rinsed, dried, and then replaced on the machine. The periods of inoperation can obviously be kept to a minimum by mounting a plurality of cylinders on one rotary element.
A machine of the type described above can produce a minimum of 150 g, that is, 50 km/hour of a high quality copper wire, using a single drawing tool. A single operator without any special skill can easily control at least two machines of this type operating in parallel.
Example 2
This example illustrates a method of removing copper wire from the surface, according to a generatrix, of a cold-hammered copper wire billet having a diameter of 0.50 mm. It is provided in reference to the simplified diagram shown in FIG. 3.
A unit comprising a wind-off element 16 and a wind-on element 17 and operating with controlled wire tension enables the billet 18 to be advanced in front of the drawing tool 19 at a rate of approximately 1,000 m per minute. Opposite the tool 19, the billet wire passes over a rotating cylinder 20 which is made of a hard material and which preferably comprises a small circular groove designed to guide the wire 18. The combined effect of the wire passing over the cylinder 20 and the rewinding tension at 17 ensures that the billet is advanced at a regular rate in front of the tool 19.
According to an improvement, the billet 18 can be flattened on the cylinder 20 by means of a press roller 21 before the wire passes in front of the tool 19. This mode of operation substantially increases the linear output R.
As in example 1, the fine wire 22 which is produced with a diameter of 0.02 mm, passes through a mechanical tension accumulator-regulator 23 before being wound on the receiving spool 24.
Under these operating conditions, when R = 1, the production rate is 10 km wire (or 30g) in 10 minutes. This corresponds to a rate of 60 km/hour (or 180g wire). A single operator without any special skill can control a plurality of similar machines operated simultaneously.
The invention is obviously not limited to the embodiments and applications described above and may be used to produce various types of wires, metal or otherwise, according to different variants, comprising the main features which are described above and in the claims. The invention makes it possible to produce narrow wires from materials which are reputedly very difficult, if not impossible to draw, for example, magnesium, titanium, etc. In view of the fact that a very fine wire is directly produced in a single step and in view of the considerable reduction in material and work, the new process according to the invention is characterized by extremely advantageous cost factors as compared to the drawing processes currently employed.
|
Fine wire of indefinite length is produced at a high rate and in an economical manner from the surface of a billet, sheet or the like by creating a swelling on the surface of the work and forcing the swelling through a die in a single step.
| 1
|
This application is a National Stage Application of International Application Number PCT/GB2004/000457, filed Feb. 6, 2004; which claims the benefit of the filing date for U.S. Provisional Application Ser. No. 60/445,454, filed Feb. 7, 2003.
FIELD OF THE INVENTION
The present invention relates to the treatment of anemia. This includes the treatment of anemia associated with the use of chemotherapy and radiotherapy as well as the treatment of anemia arising from chronic renal failure or treatment of HIV-infected patients with AZT (zidovudine). The present invention also relates to reducing drug toxicity and enhancing drug efficiency. In particular, the present invention relates to the use of medium-chain length fatty acids such as capric acid, caprylic acid, or salts or triglycerides thereof or mono- or diglycerides or other analogues thereof as a stimulator of the production of erythrocyte progenitors, in particular Burst Forming Unit-Erythroid (Erythrocyte) cells or BFU-E cells.
BACKGROUND OF THE INVENTION
Chemotherapy refers to the use of cytotoxic agents such as, but not limited to, cyclophosphamide, doxorubicin, daunorubicin, vinblastine, vincristine, bleomycin, etoposide, topotecan, irinotecan, taxotere, taxol, 5-fluorouracil, methotrexate, gemcitabine, cisplatin, carboplatin or chlorambucil in order to eradicate cancer cells and tumors. However, these agents are non-specific and, particularly at high doses, they are toxic to normal and rapidly dividing cells. This often leads to various side effects in patients undergoing chemotherapy and radiation therapy. Myelosuppression, a severe reduction of blood cell production in bone marrow, is one such side effect. It is characterized by anemia, leukopenia, neutropenia, agranulocytosis and thrombocytopenia. Severe chronic neutropenia is also characterized by a selective decrease in the number of circulating neutrophils and an enhanced susceptibility to bacterial infections.
The essence of treating cancer with chemotherapeutic drugs is to combine a mechanism of cytotoxicity with a mechanism of selectivity for highly proliferating tumor cells over host cells. However, it is rare for chemotherapeutic drugs to have such selectivity. The cytotoxicity of chemotherapeutic agents limits administrable doses, affects treatment cycles and seriously jeopardizes the quality of life for the cancer patient.
Although other normal tissues may also be adversely affected, bone marrow is particularly sensitive to proliferation-specific treatments such as chemotherapy or radiation therapy. Acute and chronic bone marrow toxicity is a common side effect of cancer therapies which leads to decreases in blood cell counts and anemia, leukopenia, neutropenia, agranulocytosis and thrombocytopenia One cause of such effects is a decrease in the number of replicating hematopoietic cells (e.g., pluripotent stem cells and other progenitor cells) caused by both a lethal effect of cytotoxic agents or radiation on these cells and by differentiation of stem cells provoked by a feed-back mechanism induced by the depletion of more mature marrow compartments. The second cause is a reduction in self-renewal capacity of stem cells, which is also related to both direct (mutation) and indirect (aging of stem cell population) effects (Tubiana, M., et al., Radiotherapy and Oncology 29:1-17, 1993). Thus, cancer treatments often result in a decrease in red blood cells or erythrocytes in the general circulation.
Erythrocytes are non-nucleated biconcave disk-like cells which contain hemoglobin and are essential for the transport of oxygen. Hemoglobin is a tetrapeptide which contains four binding sites for oxygen. Anemia refers to that condition which exists when there is a reduction below normal in the number of erythrocytes, the quantity of hemoglobin, or the volume of packed red blood cells in the blood as characterized by a determination of the hematocrit. The hematocrit or “red blood cell volume” is considered to be a particularly reliable indicator of anemia. Typically, in normal adults, average values for red blood cell count (millions/mm 3 ), hemoglobin (g/100 ml) and hematocrit or volume packed red blood cells (ml/100 ml) for females and males (at sea level) are 4.8±0.6 and 5.4±0.9, 14.0±2.0 and 16.0±2.0 and 42.0±5.0 and 47.0±5.0, as described in Harrison's Principles of Internal Medicine, 8 th Edition, Appendix-Table A-5, McGraw Hill (1977). In normal humans, erythrocytes are produced by the bone marrow and released in the circulation, where they survive approximately 120 days. They are subsequently removed by the monocyte-phagocyte system.
Anemia is a symptom of various diseases and disorders. Therefore, anemia may be classified in terms of its etiology. For example, aplastic anemia is characterized by absence of regeneration of erythrocytes and is resistant to therapy. In such patients, there is a marked decrease in the population of myeloid, erythroid and thrombopoietic stem cells, which results in pancytopenia Hemolytic anemia arises from shortened survival of erythrocytes and the inability of the bone marrow to compensate for their decreased life span. It may be hereditary or may result from chemotherapy, infection or an autoimmune process. Iron deficiency anemia refers to a form of anemia characterized by low or absent iron stores, low serum iron concentration, low hemoglobin concentration or hematocrit, etc. Iron deficiency is the most common cause of anemia. Pernicious anemia, which most commonly affects adults, arises from a failure of the gastric mucosa to secrete adequate intrinsic factor, resulting in malabsorption of vitamin B12. Sickle cell anemia arises from a genetically determined defect in hemoglobin synthesis. It is characterized by the presence of sickle-shaped erythrocytes in the blood. The above are only exemplary of the many different anemias known to medicine. However, within the context of the current invention, it is of particular interest to address anemia associated with the use of chemotherapy or radiotherapy in the treatment of cancer. According to a statement published in BioWorld Today (page 4; Jul. 23, 2002), approximately 1.2 million cancer patients will undergo cytotoxic chemotherapy in the United States this year and about 800,000 or 67% of them will become anemic. Additionally, anemia is also associated with end-stage renal disease as is the case for patients who require regular dialysis or kidney transplantation for survival. This fills under the umbrella of chronic renal failure or the clinical situation in which there is a progressive and usually irreversible decline in kidney function.
Erythropoietin (EPO) is a glycoprotein with a molecular weight of 34,000 which is produced in the kidney. EPO stimulates the division and differentiation of committed erythroid progenitors in the bone marrow (BFU-E cells) and maintains cell viability (inhibition of apoptosis of BFU-E and CFU-E cells). The biological effects of EPO are receptor mediated. Amino acid identity amongst different animals is 92% between human EPO and monkey EPO and 80% between human EPO and mouse EPO. The primary stimulus for the biosynthesis of EPO is tissue hypoxia. However, as may be seen from the above, EPO has significant therapeutic potential for the treatment of certain anemias. For example, EPO can be used to treat anemia arising from a diminished endogenous production of EPO, which may result from a damaged or non-functional kidney (e.g., chronic renal failure as discussed above). Alternatively, EPO can be used to treat anemia arising from damaged bone marrow and subsequently diminished proliferation of erythrocyte progenitors (e.g., BFU-E cells) which results from treatment of cancer patients with cytotoxic chemotherapy or radiotherapy (as also discussed above). Various forms of recombinant EPO are available on the market. They differ by their expression system used for their manufacture and by their sites and degree of glycosylation of the protein. Epoetin alpha is expressed in CHO cells and is available under the trade name of Procrit®, Epogen® or Eprex®. Like EPO, Epoetin alpha has three N-linked glycosylation sites at asparagine (Asn) residues; Asn 19, Asn 33 and Asn 78. Epoietin beta is N-glycosylated at three sites but epoetin omega is N-glycosylated at Asn 24, Asn 28, Asn 83 and partially O-glycosylated at serine (Ser 126). Recently, a hyperglycosylated version of EPO has been approved which contains five N-linked glycosylation sites. It is a slow or extended release form of epoetin alpha available under the trade name of Aranesp®. This protein displays enhanced biological activity compared to the natural form, due to its approximately three-fold longer serum half-life. However, the use of these glycosylated proteins is expensive and restricted since they have to be produced by recombinant technology. Such post-therapeutic ameliorative treatments are unnecessary if patients are “chemoprotected” from immune suppression. Therefore, there is a need for novel compositions and methods to reduce the undesirable side effects of myelosuppressive states induced by chemotherapy and radiation therapy.
SUMMARY OF THE INVENTION
The present invention satisfies the need for chemoprotective agents by providing a novel method for the stimulation of the hematopoietic system in a mammal, including a human. The present invention also provides a novel method for treating the myelosuppressive effects of chemotherapy and radiotherapy and any other situation in which the stimulation of the hematopoietic system can be of therapeutic value such as, but not limited to, anemia.
In accordance with this method, a composition comprising capric acid, caprylic acid, or metallic salts (sodium, potassium, calcium, magnesium) or triglycerides thereof or mono- or diglycerides or alkyl esters or other analogues thereof in a pharmaceutically acceptable carrier is administered to a mammal, particularly humans, in an amount effective to significantly reduce the adverse effects of chemotherapy and radiation therapy.
Accordingly, it is an object of the present invention to provide compositions using capric acid, caprylic acid, or metallic salts (sodium, potassium, calcium, magnesium) or triglycerides thereof or mono- or diglycerides or alkyl esters or other analogues thereof for the production of chemoprotective pharmaceutical compositions as a single agent or as a combination of two or more agents with and/or without other chemotherapeutic agents or such drugs which induce a state of myelosuppression.
Another object of the present invention relates to the use of capric acid, caprylic acid or sodium salts or triglycerides thereof or mono- or diglycerides thereof or related compounds as a hematopoiesis stimulating factor.
Furthermore, the present invention includes compositions containing capric acid or caprylic acid or sodium salts or triglycerides thereof or mono- or diglycerides or other analogues thereof and the use of such compounds for the treatment of myelosuppression and subsequent anemia and immunosuppression.
It is an object of the present invention to provide a method effective for providing chemoprotection of a mammal, including a human.
Another object of the present invention is to provide a method effective for increasing the efficacy of chemotherapy and radiation therapy in a mammal, including a human.
Yet another object of the invention is to provide methods for using more usual doses or even increasing the dose of chemotherapeutic compositions necessary to achieve a better therapeutic benefit, while avoiding increased side effects.
Still another object of the present invention is to provide a method effective for reducing or eliminating chemotherapy-induced anemia in a mammal, including a human.
Another object of the present invention is to provide a method for treating anemia arising from chronic renal failure, especially in those patients with end-stage renal disease.
Yet another object of the present invention is to provide a method for treating anemia arising from other medical procedures such as orthopedic surgery or the use of other drugs such as AZT.
Finally, another object of the present invention is to provide a method that causes minimal or no adverse effects to the recipient.
These and other objects, features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiment and the appended claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a significant increase in spleen red cell count observed with oral pre-treatment with tricaprin, capric acid or sodium caprate in cyclophosphamide treated mice.
FIG. 2 illustrates a significant increase in proliferation of spleen red cell count observed with oral and intravenous administration pre-treatments with sodium caprate in cyclophosphamide treated mice.
FIG. 3 illustrates a significant increase in bone marrow red cell count was observed with sodium caprate and GM-CSF (high concentration, 1 μg/kg) in cyclophosphamide treated mice.
FIG. 4 illustrates a significant increase in the number of peripheral blood cell when sodium caprate was used alone.
FIG. 5 illustrates an enhanced number of CFU-E and CFU-GEMM in normal mice when sodium caprate is used.
FIG. 6 represents a typical experiment on the effect of tricaprin on bone marrow proliferation.
FIG. 7 represents a typical experiment on the effect of tricaprylin on bone marrow proliferation.
DETAILED DESCRIPTION OF THE INVENTION
High dose chemotherapy and radiation destroy hematopoietic cells in bone marrow. Subsequently, the patient can be severely depleted in erythrocytes, platelets and neutrophils. Anemia results in fatigue, a lack of energy and shortness of breath. Thrombocytopenia leads to prolonged clotting time and bleeding disorders. Neutropenia places the patient at increased risk of infection. Myelosuppression is a dose-limiting factor in cancer treatment.
The present invention relates to a method of restoring the patient's hematopoietic system. Current methods employed to do the same make use of cytokines or glycoprotein growth factors. For example, erythropoietin can be used to stimulate the proliferation and maturation of responsive bone marrow erythroid cells. Erythropoietin is approved for human use for the treatment of anemia where appropriate: e.g., anemia arising from the inability to produce a sufficient number of erythrocytes. However, there are limitations which restrict the use of erythropoietin. Indeed, many of these limitations are common to the medical use of recombinant glycoprotein cytokines—availability, toxicity and efficacy, especially with chronic use. For example, some patients treated with recombinant human erythropoietin develop an immune response to the glycoprotein which results in pure red cell aplasia. When the latter occurs, the antibody developed to the recombinant protein also attacks the patient's equivalent or endogenous protein. Subsequently, the patient develops a worst anemia than before drug treatment.
Medium-chain triglyceride(s) (MCT) can be made by esterifying glycerol with fatty acids having carbon chain lengths of 8 (C8, octanoic acid or caprylic acid) or 10 (C10, decanoic acid or capric acid). MCT is usually a mixture of glycerol esters of C8 and C10 fatty acids; however, MCT can also contain small amounts (2±1% each) of glycerol esters of C6 (hexanoic acid or caproic acid) and C12 (dodecanoic acid or lauric acid). Long-chain triglyceride(s) (LCT), on the other hand, consist of glycerol esterified with fatty acids with carbon chain lengths of greater than 12 atoms. Typical fatty acids present in LCT include palmitic (C16) and stearic (C18) acids. Unlike MCT, LCT is the primary component of dietary fats. Indeed, MCT and LCT have significantly different biological properties. Some of the physiological differences between MCT and LCT are described in Harrison's Principles of Internal Medicine, 8 th Edition, 1520-1521 (1977); 15 th Edition, 1668-1669 (2001). For example, MCT, in contrast to LCT, do not require hydrolysis by pancreatic lipase, since they can be absorbed by intestinal epithelial cells.
MCT and their constituent medium-chain fatty acids are nontoxic materials which are used in the food and pharmaceutical industries. For example, Traul, K. A., et al. ( Food and Chemical Toxicology 38:79-98, 2000) state that MCT have been utilized in an increasing number of food and nutrition applications because they offer a number of advantages over LCT. MCT are also used primarily as emulsifiers in various human and veterinary pharmaceutical preparations and in cosmetics. They refer to a number of toxicological studies which support the safety of MCT. For example, they note that the safety of human dietary consumption of MCT, up to levels of 1 g/kg, has been confirmed in clinical trials. C8 and C10 fatty acids possess similar safety and use. For example, in The Merck Index, 11 th Edition, 266 (1989) caprylic acid is reported to have an LD 50 (oral, rats)=10.08 g/kg which is essentially nontoxic. In fact, according to part 184 of the Code of Federal Regulations (CFR), the U.S. Food and Drug Administration (FDA) has granted caprylic acid a GRAS (Generally Recognized As Safe) affirmation. Similarly, according to part 172 (CFR) free fatty acids (e.g., capric, caprylic) and their metallic salts are recognized as safe additives for use in food. As noted by Dimitrijevic, D., et al. ( Journal of Pharmacy and Pharmacology 53:149-154, 2001), capric acid (sodium salt) is approved for human use in Japan and Sweden as an absorption enhancer for rectal drug products. U.S. Pat. No. 4,602,040 (1986) describes the use of MCT as a pharmaceutical excipient. More recently, PCT publication WO 01/97799 describes the use of medium-chain fatty acids, in particular caprylic and capric acids, as antimicrobial agents.
However, until the unexpected findings disclosed herein, the effectiveness of medium-chain fatty acids such as capric acid, caprylic acid or metallic salts or mono-, di- or triglycerides (MCT) thereof or related compounds for the stimulation of production of erythrocytes from erythroid progenitor cells, or erythropoiesis, was unknown. As described herein, MCT may comprise triglycerides of C8 (caprylic) and C10 (capric) fatty acids which constitute at least 98% of the activity pertaining to the stimulation of hematopoiesis and erythropoiesis. The former activity was described in our PCT publication WO 02/83120, but stimulation of erythropoiesis and treatment of anemia was not previously described. Indeed, this discovery was completely unexpected since very little has been reported in the literature with regard to lower molecular weight or smaller molecules than glycoproteins being able to stimulate erythropoiesis. A synthetic dimeric form of an erythropoietin mimetic peptide (EMP) was described by Wrighton, N.C., et al. ( Nature Biotechnology 15:1261-1265, 1997). Although considerably smaller than erythropoietin, EMP is a polypeptide which contains twenty amino acids in each monomer. More importantly, EMP is significantly less active than erythropoietin. More recently, PCT publication WO 02/19963 describes synthetic erythropoiesis protein (SEP) as a synthetic stabilized polypeptide with erythropoietin-like biological activity. The reported advantage of SEP is that it is a stabilized, relatively longer, half-life molecule which is made by chemical synthesis and not by relatively more expensive recombinant technology. Stabilization is achieved by the introduction of ethylene glycol units (e.g., PEG) and so this introduces an additional level of complexity into the preparation of SEP. In summary, the prior art teaches that the stimulation of production of erythrocytes requires the use of large polypeptide or protein molecules.
The present invention relates to the use of medium-chain fatty acids or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or a MCT composition as a hematopoiesis activation or growth factor and, more particularly, as a stimulator of the production of erythrocyte progenitor cells. When used in chemotherapy and radiotherapy, medium-chain fatty acids or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT is administered before, during and/or after the treatment in order to shorten the period of anemia and to accelerate the replenishment of the hematopoietic system. Furthermore, it is possible to use a combination of medium-chain fatty acids along with their metallic salts or triglycerides thereof or mono- or diglycerides thereof or other analogues thereof and/or MCT at multiple points relative to treatment with chemotherapy and radiotherapy (e.g., fatty acids before treatment and MCT after). Alternatively, it is possible to administer the combination simultaneously: before, during and/or after treatment with chemotherapy and radiotherapy. In severe anemia arising from a diminished production of EPO, medium-chain fatty acids or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT is used as the therapeutic agent Medium-chain fatty acids or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT can also be used after bone marrow transplantation in order to stimulate bone marrow stem cells thus shortening the time period for recovery from anemia.
As used herein, “medium-chain fatty acids such as capric acid or caprylic acid or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT composition” refers to a composition comprising said active ingredient and one or more pharmaceutically acceptable carriers.
As used herein, the term “pharmaceutically acceptable carrier” refers to a substance that does not interfere with the physiological effects of medium-chain fatty acids such as capric acid or caprylic acid or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT composition and that is not toxic to mammals including humans.
The capric or caprylic acid or salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or a MCT composition of the present invention may be formulated using capric or caprylic acid or salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT and pharmaceutically acceptable carriers by methods known to those skilled in the art ( Merck Index , Merck & Co., Rahway, N.J.). These compositions include, but are not limited to, solids, liquids, oils, emulsions, gels, aerosols, inhalants, capsules, pills, patches and suppositories.
All methods include the step of bringing the active ingredient(s) into association with the carrier which constitutes one or more accessory ingredients.
As used herein, the term “chemotherapy” refers to a process of killing proliferating cells using a cytotoxic agent. The phrase “during the chemotherapy” refers to the period in which the effect of the administered cytotoxic agent lasts. On the other hand, the phrase “after the chemotherapy” is meant to cover all situations in which a composition is administered after the administration of a cytotoxic agent regardless of any prior administration of the same and also regardless of the persistence of the effect of the administered cytotoxic agent.
When the method of this invention is applied to chemotherapy, a capric or caprylic acid or salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or a MCT composition can be administered prior to, during, or subsequent to the chemotherapy (i.e., prior to, during, or subsequent to the administration of a cytotoxic agent).
By “cytotoxic agent” is meant an agent which kills highly proliferating cells: e.g., tumors cells, virally infected cells, or hematopoietic cells. Examples of a cytotoxic agent which can be used to practice the invention include, but are not limited to, cyclophosphamide, doxorubicin, daunorubicin, vinblastine, vincristine, bleomycin, etoposide, topotecan, irinotecan, taxotere, taxol, 5-fluorouracil, methotrexate, gemcitabine, cisplatin, carboplatin or chlorambucil, and an agonist of any of the above compounds. A cytotoxic agent can also be an antiviral agent e.g., AZT (i.e. 3′-azido-3′-deoxythymidine) or 3TC/lamivudine (i.e. 3-thiacytidine).
As used herein, the term “chemoprotection” refers to protection provided to a mammal from the toxic effects arising from treatment of the mammal with a chemotherapeutic agent Most often, the latter is a cytotoxic agent whose therapeutic effect arises from its ability to interfere with or inhibit some aspect of DNA replication, RNA transcription, or subsequent translation of protein. Therefore, a chemoprotective agent refers to any compound administered to a mammal which would protect the mammal, or facilitate the recovery of the animal, from the toxic effects resulting from treatment of the mammal with a chemotherapeutic agent.
Anemia can be diagnosed and its severity can be determined by a person skilled in the art. The term “anemia” may refer to that condition which exists when there is a reduction below normal in the number of erythrocytes, the quantity of hemoglobin, or the volume of packed red blood cells. Such clinical criteria are subject to variablity. Without limitation, anemia may be the result of a reduction in the mass of circulating red blood cell. Efficacy of treatment can also be determined by a person skilled in the art. It may provide a palliative effect.
In one preferred embodiment, the pharmaceutical composition is in the form of any suitable composition for oral, sublingual, rectal, topical administration or inhalation (nasal spray), intramuscular, intradermal, subcutaneous or intravenous administration for use in the treatment of anemia.
It will be appreciated that the amount of a composition of the invention required for use in the treatment will vary with the route of administration, the nature of the condition being treated, the age and condition of the patient, and will ultimately be at the discretion of the attending physician. The desired dose may be conveniently presented in a single dose or as divided doses taken at appropriate intervals, for example as two, three or more doses per day as necessary to effect or bring about treatment. The term “treatment” or “treating” includes any therapy of existing disease or condition and prophylaxis of the disease or condition (e.g., anemia) in a mammal. This includes (a) preventing the disease or condition from occurring in a patient which may be predisposed to the disease but has not yet been diagnosed as having it, (b) inhibiting or arresting the development of the disease or condition and (c) relieving the disease or condition by causing its regression or the amelioration of one or more symptoms.
While it is possible that, for use in therapy, medium-chain fatty acids or metallic salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or MCT may be administered as the raw chemical, it is preferable to present the active pharmaceutical ingredient as a pharmaceutical formulation or composition. A nontoxic composition is formed by the incorporation of any of the normally employed excipients such as, for example but not limited to, mannitol, lactose, trehalose, starch, magnesium stearate, talcum, cellulose, carboxymethyl cellulose, glucose, gelatin, sucrose, glycerol magnesium carbonate, sodium citrate, sodium acetate, sodium chloride, sodium phosphate and glycine.
In a preferred embodiment of the invention, the amount of active ingredient administered is such that the concentration in the blood (free and/or bound to serum albumin) is greater than 1 μM In other embodiments, the concentration in the blood may be greater than 1 mM In another preferred embodiment of the invention, it might be necessary to achieve a sufficient local concentration of an active pharmaceutical ingredient to obtain a biologically or medically significant effect in a target tissue (e.g. bone marrow). Such a relatively high concentration of active pharmaceutical ingredient may be required, at least at the target tissue, as it may be necessary for the capric acid or caprylic acid or salts or triglycerides thereof or mono- or diglycerides or other analogues thereof or a MCT composition of the present invention to form a micelle or aggregate structure in order to elicit a biological response. A single dose may be comprised of a total amount from about 1 g to about 10 g of active ingredient (and any intermediate ranges thereof).
In another embodiment, the pharmaceutical composition is in a form suitable for enteral, mucosal (including sublingual, pulmonary and rectal) or parenteral (including intramuscular, intradermal, subcutaneous and intravenous) administration. The formulations may, where appropriate, be conveniently presented in discrete dosage units and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing into association the active pharmaceutical ingredient with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired form. When desired, the above-described formulations adapted to give sustained release of the active pharmaceutical ingredient may be employed. Sustained release formulations well known to the art include the use of liposomes, biocompatible polymers, a bolus injection or a continuous infusion.
Medium-chain fatty acids or salts or triglycerides thereof or mono- or diglycerides or other analogues or MCT can also be used in combination with other therapeutically active agents such as cytotoxic anticancer agents or other anticancer agents (immune modulating or regulating drugs or therapeutic vaccines or anti-angiogenesis drugs, etc.) or immune suppressive drugs (including anti-inflammatory drugs). The individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations. The combination referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination defined above together with a pharmaceutically acceptable carrier thereof comprise a further aspect of the invention.
EXAMPLES
The following further illustrate the practice of this invention but are not intended to be limiting thereof.
Example 1: Chemoprotection Studies: In Vivo Induction of Immune Cell Proliferation or Protection by MCT
Female C57BL/6 mice, 6 to 8 week old, were immunosuppressed by treatment with 200 mg/kg of cyclophosphamide (CY) or 80 mg/kg 5-fluorouracil (5-FU) administered intravenously at day 0. To examine the immunoprotective effect of MCT or other compounds, mice were pre-treated orally at day −3, −2 and −1 at day 0 with the compound. Mice were sacrificed at day +5 by cardiac puncture and cervical dislocation. Then, a gross pathological observation of the femurs (as a source of bone marrow cells) was recorded.
Table 1 represents the gross pathological observation of the femurs obtained in cyclophosphamide immunosuppressed animals in the presence or in the absence of compounds. Results show that the femur of a normal mouse has a vivid red color, demonstrating the proliferative state of the hematopoietic progenitor cells and their progeny. When treated with cyclophosphamide, the bone marrow is depleted from hematopoietic cells and has a transparent “white” appearance indicating a suppression of the proliferation of hematopoietic progenitors originating from the bone marrow. However, under cytotoxic-induced immunosuppressive conditions, the addition of MCT, tricaprylin, tricaprin, capric acid or sodium caprate reversed the effect of cyclophosphamide. This resulted in a red appearance of the femur, indicating the expansion of hematopoietic progenitor cells, in particular the erythrocyte population. The same results are observed when immunosuppression is induced by 5-fluorouracil (5-FU).
TABLE 1
Effect of cyclophosphamide (CY), CY + MCT, CY + tricaprylin,
CY + tricaprin, CY + capric acid and CY + sodium caprate
on the appearance of bone marrow from the femur: gross
pathological observation.
Gross pathological observations: Bone Marrow Color
Control
Vivid red
CY
White, almost translucent
CY + MCT
Red
CY + tricaprylin
Red
CY + tricaprin
Red
CY + capric acid
Red
CY + sodium caprate
Red
Example 2: Chemoprotection Studies: In Vivo Induction of Immune Cell Proliferation or Protection: Comparison of Tricaprin, Capric Acid and Sodium Caprate
Effect of tricaprin, capric acid and sodium caprate on in vivo induction of immune cell proliferation or protection was undertaken following the protocol described in example 1. After the sacrifice, tissues were crushed in PBS buffer and cells were counted on a hemacytometer.
A significant increase in spleen red cell count was observed with oral pre-treatment with tricaprin, capric acid or sodium caprate in cyclophosphamide treated mice ( FIG. 1 ). Further, some treated animals return to a “baseline level” in terms of the spleen red cell count as compared to non-immunosuppressed animals (control).
Example 3: Chemoprotection Studies: In Vivo Induction of Immune Cell Proliferation or Protection: Oral and Intravenous Dose-Response of Sodium Caprate
Effect of oral and intravenous administration of sodium caprate on in vivo induction of immune cell proliferation or protection was undertaken following the protocol described in example 1. After sacrifice, tissues were crushed in PBS buffer and cells were counted on a hemacytometer. A significant increase in proliferation of spleen red cell count was observed with oral and intravenous administration pre-treatments with sodium caprate in cyclophosphamide treated mice ( FIG. 2 ). Furthermore, intravenous administration of sodium caprate increases the spleen red cell counts to the baseline level of control mice (non-immunosuppressed).
Example 4: Chemoprotection Studies: In Vivo Induction of Erythrocyte Proliferation or Repopulation: Comparison with GM-CSF
Effect of oral and intravenous administration of sodium caprate and GM-CSF on in vivo induction of immune cell proliferation or protection was undertaken following the protocol described in example 1. After sacrifice, tissues were crushed in PBS buffer and cells were counted on a hemacytometer. A significant increase in bone marrow red cell count was observed with sodium caprate and GM-CSF (high concentration, 1 μg/kg) in cyclophosphamide treated mice ( FIG. 3 ). Furthermore, when used in combination with GM-CSF, an additive increase in bone marrow red cell count occurs.
Additionally, sodium caprate, when used alone, was able to induce a significant increase in the number of peripheral blood cell as demonstrated in FIG. 4 .
Example 5: Anemia Model: Ex Vivo Induction of Bone Marrow Colony Forming Unit (CFU) Proliferation/Differentiation or Protection by Sodium Caprate
To examine the immunoprotective or immunorestorative effect of sodium caprate in an anemia model, BALB/c mice were pre-treated intravenously at day −3, −2 and −1 with compound. Anemia was induced by treatment with 60 mg/kg phenylhydrazine administered intraperitonealy at day 0 to female BALB/c mice, 6 to 8 week old. Mice were sacrificed at day +6 by cardiac puncture and cervical dislocation. Then, bone marrow cells were obtained from femur. Cells were flushed and washed with PBS. Based on the viable cells count, the cells were resuspended at a concentration of 5×10 5 cells per ml in IMDM media supplemented with 2% FBS. From these cells, two replicates of 3×10 4 cells per dish were plated in Methocult medium so that a colony forming unit (CFU) formation assay could be undertaken. CFU-E and BFU-E were recorded after 2 to 3 days culture. CFU-GM and CFU-GEMM were recorded after 14 to 16 days culture.
As illustrated in FIG. 5 , sodium caprate enhances the number of CFU-E and CFU-GEMM in normal mice. In phenylhydrazine-induced anemia mice, sodium caprate induces a strong increase in CFU-E, CFU-GM and CFU-GEMM.
Example 6: Tricaprin and Tricaprylin Increase the Proliferation of In Vitro Human Bone Marrow Cells
Bone marrow cells were obtained from the sternum of cancer patients. Cells were washed with PBS and resuspended at a concentration of 2×10 6 cells per ml. Cells were cultured in RPMI/FBS media in the presence or the absence of tricaprin or tricaprylin for 48 and 72 hours at 37° C. After incubation, cells were pulsed with 1 μCi of [ 3 H]-thymidine for 6 hours. Plates were harvested on a Tomteck and counted on a Microbeta β-counter. Incorporation of [ 3 H]-thymidine in the DNA is a direct indication of the cell proliferation.
FIG. 6 represents a typical experiment on the effect of tricaprin on bone marrow proliferation. Tricaprin increases bone marrow proliferation by 3 to 4 fold relative to the control. Furthermore, when used in combination with erythropoietin (EPO), an additive or synergistic increase in bone marrow proliferation occurs at 48 and 72 hours respectively.
FIG. 7 represents a typical experiment on the effect of tricaprylin on bone marrow proliferation. Tricaprylin increases bone marrow proliferation by 2 fold relative to the control. Furthermore, when used in combination with erythropoietin (EPO), a synergistic increase in bone marrow proliferation occurs.
Example 7: Tricaprin Increases the Proliferation of In Vitro Human Bone Marrow BFU-E (Red Blood Cell Progenitor) Colony Formation and CFU-GEMM
Bone marrow cells were obtained from the sternum of various cancer patients. Cells were washed with PBS and resuspended at a concentration of 2×10 6 cells per ml. Cells were cultured in RPMI/FBS or Myelocult (Stem cell technology, Vancouver)/FBS media in the presence or the absence of tricaprin for 5 days at 37° C. After incubation, cells were harvested, washed and counted. Based on the viable cells count, the cells were resuspended at a concentration of 5×10 5 cells per ml in IMDM media supplemented with 2% FBS. From these cells, four replicates of 2.5×10 4 cells per dish were plated in Methocult medium so that a colony forming unit (CFU) formation assay could be undertaken. CFU-GM, CFU-GEMM and BFU-E were recorded after 14 to 16 days culture.
Tables 2 and 3 represent two experiments on the effect of tricaprin on bone marrow cell colony formation in RPMI/FBS medium. The presence of tricaprin increases the number of CFU-GEMM (up to 3 times) and BFU-E colonies formation (up to 13 times). The latter cells are the progenitors of the red blood cells.
Tables 4 and 5 represent two experiments which demonstrate the effect of tricaprin on bone marrow cell colony formation in Myelocult/FBS medium, which is a more enriched medium (supplemented with additional growth factors). The presence of tricaprin increases the number of CFU-GEMM (up to 2 times) and BFU-E colonies formation (up to 6 times), which are the progenitors of the red blood cells.
TABLE 2
Effect of tricaprin on in vitro human hematopoietic progenitors
(CFU formation) cultured in RPMI/FBS medium.
EXPERIMENT 1
BFU-E
CFU-GM
CFU-GEMM
TOTAL CFC*
Control
10
26
1.25
38
Tricaprin 10%
130
26
4.75
161
TABLE 3
Effect of tricaprin on in vitro human hematopoietic progenitors
(CFU formation) cultured in RPMI/FBS medium.
EXPERIMENT 2
BFU-E
CFU-GM
CFU-GEMM
TOTAL CFC*
Control
15
32
1.25
49
Tricaprin 10%
121
25
4
150
TABLE 4
Effect of tricaprin on in vitro human hematopoietic progenitors
(CFU formation) cultured in Myelocult/FBS medium.
EXPERIMENT 1
BFU-E
CFU-GM
CFU-GEMM
TOTAL CFC*
Control
54
41
2.5
98
Tricaprin 10%
380
17
4.75
401
TABLE 5
Effect of tricaprin on in vitro human hematopoietic progenitors
(CFU formation) cultured in Myelocult/FBS medium.
EXPERIMENT 2
BFU-E
CFU-GM
CFU-GEMM
TOTAL CFC*
Control
49
26
2.5
77
Tricaprin 10%
268
34
4.25
306
*CFC = Colony Forming Cells
|
Use of a composition comprising a compound of any of formulae I, II, Ila, III and Illa; or a combination thereof wherein each R 1 is independently C 7-11 alkyl; A and B are independently H or CO—R 1 ; R 2 is H or C 1-4 alkyl; M is a metal monocation (k=1) or dication (k=2); Y is 0 or NH; and Z is 0, NH, CH 2 O or a bond; for the manufacture of a medicament for stimulating erythropoiesis. Preferably, the composition further comprises human erythroporietin.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of International Patent Application No. PCT/CN2007/000442, filed Feb. 8, 2007, which claims priority to Chinese Patent Application Nos. 200610058052.X and 200610067530.3, both filed Feb. 28, 2006, each of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the communication security technology, and more particularly, to a proxy server, a method for realizing proxy, a secure communication system with the proxy server, and a secure communication method between LE devices.
BACKGROUND
[0003] In recent years, with increasing progress in the communication technology, the communication industry develops rapidly, and the spectrum resources become very precious. Thus, to make a full use of the limited spectrum resources, a license-exempt band (LE band) is particularly designated by International Telecommunications Union. On the premise of not affecting normal work of other devices, LE devices may occupy the band willfully.
[0004] Working at the LE band, the LE devices need to get accustomed to the environment, i.e. to detect and avoid interferences or to negotiate with interference sources. Therefore, the LE devices should negotiate with other LE devices on how to share the band, and therefore signaling communication between the LE devices is involved. As two LE devices do not know the address of each other in advance, one has to broadcast its own address, and the other may establish the communication, as desired.
[0005] As the two devices in need of resource negotiation have conflicts on resources, their coverage areas overlap. Through terminals in the common coverage area, the two LE devices may broadcast addresses in a wireless manner. After acquiring the address of each other, the two devices switch to a wired manner to perform the subsequent negotiation.
[0006] Here, the address generally refers to an IP address. In fact, the two devices in need of resource negotiation usually belong to two different operators or two networks without any mutual trust, and it is quite risky to broadcast over air interfaces the service IP address of a base station (BS). If any malicious device captures the IP address of the LE BS, the device may pretend to need to negotiate resource, or may attack the LE BS to crash the BS.
[0007] Further, in some areas, the use of a certain band is under non-exclusive license authorization. In other words, when some device is granted with the license of the band, other devices may also get the right to use this band without informing the authorized device.
[0008] In another circumstance, though having obtained the exclusivity of a band within an area, a certain enterprise or operator does not have the ability to or unwilling to set the stations in the manner of planning first and then site layout, instead, wishes the devices to automatically negotiate resource allocation flexibly according to the actual occupation of the air interface resources.
[0009] For ease of illustration, the devices/BSs in the above three circumstances are generally referred to as LE devices/BSs or coexistent BSs.
[0010] In the network, none of the parameters such as location, occupied resources, and transmit power of each LE device are planned or configured in advance, but the device gets accustomed to the environment, and selects resources and negotiates allocation with other LE devices in a permitted range.
[0011] In a LE network, resource negotiation is usually performed between the devices to ensure each device to work normally or optimally. A common case where two LE BSs need to communicate is that, an IBS cannot scan any idle band after being activated, so the IBS has to negotiate with an adjacent OBS on spectrum sharing. As no reliable wireless manner can be adopted for exchanging negotiation information between the BSs in need of negotiation, the communication negotiation between the IBS and the OBS is mainly implemented in a wired manner. In this case, the IBS or OBS must know the wired contact information of each other. Here, initializing base station is abbreviated to IBS, representing a newly activated BS, and operating base station is abbreviated to OBS, representing a BS at normal work.
[0012] As the parameters like spectrum, location, transmit power, and coverage of each LE device are not planned in advance, the activation and exit of the LE device are highly random. Therefore, the OBS at normal work may not know which BSs around will be activated, and the newly activated IBS may not know which adjacent OBSs already exist. By broadcasting over the air interfaces, the IBS may send its own contact information within the range of interference, so a terminal which has received information may report the information to an OBS which the terminal belongs to, and accordingly, the OBS may initiate subsequent communication with the IBS.
[0013] In view of the above, the LE devices need to get its own address information public in a way to acquire that of the other. There are many ways to get public, for example, to transit the information to the BS of the counterpart through the terminal capable of broadcasting the contact information to the counterpart in the common coverage area when the devices have an overlap coverage, or to query the counterpart and the contact information thereof according to location or other information through a well-known area server. After obtaining the contact information of the counterpart, the devices further switch to a wired manner to perform subsequent negotiation.
[0014] The LE BSs in need of coexistent negotiation broadcast and obtain network addresses of related LE BSs directly through air interfaces or public servers, and begin contact through the public network addresses. Here, the address generally refers to the network address, i.e. IP address. In fact, the devices in need of resource negotiation usually belong to different operators or networks without any trust relationship between each other, and it is quite risky to directly broadcast the service IP address of the BS. If any malicious attacker captures the service IP address of the wireless BS, the attacker may directly attack the network port of the BS.
[0015] FIG. 1 is a schematic view of obtaining network addresses and communicating between LE BSs. Assuming that the IBS broadcasts its IP address through air interfaces, a terminal under interference transmits the received IP address to the OBS which the terminal belongs to, and the OBS directly initiates from a wired network a contact request of the IBS corresponding to the IP address based on the reported IP address. After the IBS receives the request and feeds back a message to the OBS, a subsequent communication mechanism is established. As described above, the IBS broadcasts its address over the air interfaces, that is, to disclose its network address; and therefore the IBS may be easily attacked, and the communication security between the LE BSs may be reduced.
SUMMARY
[0016] Embodiments of the present invention are mainly directed to a proxy server configured to serve as an agent for transmitting/receiving a coexistent signaling between base stations (BSs).
[0017] Embodiments of the present invention are also directed to a method for realizing proxy by the proxy server to prevent the change of network address allocation from interfering main services of a BS.
[0018] Embodiments of the present invention are further directed to a secure communication system with the proxy server to prevent the change of network address allocation from interfering main services of a BS.
[0019] Embodiments of the present invention are still further directed to a secure communication method between LE devices to ensure the LE devices not to be attacked and to remain at normal work.
[0020] In order to achieve the above objectives, technical solutions of the embodiments of the present invention are realized as fellows:
[0021] A proxy server is provided having proxy server address information, which includes a proxy database and a processing unit.
[0022] The proxy database is adapted to store BS address information of at least one BS and BS identification (BS ID) information corresponding to the BS address information.
[0023] The processing unit is adapted to replace a BS source address information in a first message from the at least one source BS with a proxy server address information of the proxy server, and send a second message carrying the proxy server address information to a target address.
[0024] The processing unit is further adapted to parse the first message, and when the first message carries no source BS ID information, add the BS ID information corresponding to the source BS address information into the first message, so as to generate the second message carrying the BS ID information and the proxy server address information.
[0025] A method for realizing proxy by the proxy server is provided, which includes the following steps.
[0026] In Step A, the BS address information of the at least one BS and the BS ID information corresponding to the BS address information are stored in advance.
[0027] In Step B, the BS source address information in the first message from the at least one BS is replaced by the proxy server address information of the proxy server.
[0028] In Step C, the second message carrying the proxy server address information is sent to the target address.
[0029] A secure communication system is provided, which includes at least one BS, and the proxy server adapted to serve as an agent for the at least one BS to perform secure communication.
[0030] A communication method for achieving secure communication between at least a first BS and a second BS is provided. In addition, the first BS has at least one first proxy server. The method includes the following steps.
[0031] In Step A, the first BS sends a first message to the second BS. The first message includes a first network address of the first proxy server and a first BS ID of the first BS.
[0032] In Step B, the second BS sends a contact request message to the first BS according to the first BS ID carried in the first message, and the first BS sends a response message to the second BS to achieve secure communication with the second BS.
[0033] Seen from the above technical solutions, in the embodiments of the present invention, the network address of a BS is only applicable in a trusted range instead of being disclosed in air interfaces and the whole network, which greatly reduces the probability of attack to the BS in a wired network. Through the above technical solutions, the embodiments of the present invention may achieve the following technical effects.
[0034] 1. As the network interface of the BS has to bear plenty of data services and related controls, the change of the IP address may cause a lot of negative impacts. However, the coexistence proxy connected to each BS only serves as an agent for transmitting/receiving a coexistent signaling, so the change of the network address allocation does not affect the main services of the BS, and multiple proxies may be back up for each other. Meanwhile, as the amount of information to be processed by the coexistence proxy is small, its required bandwidth is not high, and thus the probability of crash by an attack is small. Therefore, the coexistence proxy is advantageous in having a simple function and low cost, and multiple proxy backups can be adopted to enhance the reliability.
[0035] 2. In the present invention, the network address of a BS is only restricted in a trusted range instead of being broadcasted in a public network, thus reducing the probability of attack to the BS in a wired network.
[0036] 3. When a single proxy crashes by attack, its communication with the LE devices is remained by altering the proxy IP address or activating a backup proxy, so as to avoid interfering the service network of the BS.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a flow chart illustrating message exchange of obtaining network addresses and communicating between LE BSs;
[0038] FIG. 2 is a logic block diagram of a proxy server according to the present invention;
[0039] FIG. 3 is a flow chart illustrating a method for performing secure communication through a server acting as a proxy for at least one BS according to the present invention;
[0040] FIG. 4 is a flow chart of the work process of a proxy server in sponsor side according to the present invention;
[0041] FIG. 5 is a flow chart of the work process of a proxy server in responser side according to the present invention;
[0042] FIG. 6 is a schematic view illustrating connection modes between proxy servers and BSs according to the present invention;
[0043] FIGS. 7 a - 7 c are schematic views illustrating corresponding relationships between proxy servers and BSs according to the present invention;
[0044] FIGS. 8 a - 8 f are network topological graphs and logic block diagrams illustrating connections between proxy servers and BSs according to the present invention;
[0045] FIG. 9 is a flow chart illustrating a communication method according to an embodiment of the present invention;
[0046] FIG. 10 is a flow chart illustrating message exchange corresponding to the communication method in FIG. 9 ;
[0047] FIG. 11 is a flow chart illustrating a communication method according to another embodiment of the present invention;
[0048] FIG. 12 is a flow chart illustrating a communication method according to yet another embodiment of the present invention;
[0049] FIG. 13 is a flow chart illustrating message exchange corresponding to the communication method according to another embodiment of the present invention;
[0050] FIG. 14 is a flow chart illustrating message exchange corresponding to the communication method according to yet another embodiment of the present invention;
[0051] FIG. 15 is a flow chart illustrating message exchange corresponding to the communication method according to still another embodiment of the present invention;
[0052] FIG. 16 is a schematic flow chart illustrating processes of an IBS in the above communication method; and
[0053] FIG. 17 is a schematic flow chart illustrating processes of an OBS in the above communication method.
DETAILED DESCRIPTION
[0054] In order to make the objectives, technical solutions, and advantages of the present invention comprehensible, embodiments accompanied with drawings are described in detail below.
[0055] In the present invention, an IBS broadcasts the address of its coexistence proxy and a BS ID of its own instead of the network address adopted by services of the IBS itself. Here, the BS ID may be any identifier that uniquely identifies the BS, for example, a fixedly allocated BS identifier, or a MAC address of the BS, or even a port number of a proxy.
[0056] FIG. 2 is a logic block diagram of a coexistence proxy server 200 according to the present invention. As shown in FIG. 2 , the coexistence proxy server may also be called as a coexistence proxy. The coexistence proxy server 200 serving as an agent for transmitting/receiving a coexistent signaling between BSs may be a functional module in a device or may be an independent device.
[0057] The coexistence proxy server 200 includes a processing unit, i.e. a proxy function processing module 202 , a proxy database 204 , a BS side logic interface 206 , and a network side logic interface 208 .
[0058] In addition, the following information is stored in the proxy database 204 : IDs of all the BSs under its proxy, network addresses of all the BSs under its proxy, and mapping relationships between the IDs and the network addresses of all the BSs under its proxy.
[0059] In an exemplary embodiment, the following information is stored in the proxy database 204 : illegal proxy addresses lists; illegal message records or statistics of each proxy; and sending records or statistics of an illegal source BS address.
[0060] The proxy function processing module 202 is provided with the following basic functions:
[0061] 1. Authorized to Send Coexistent Message
[0062] 1) receiving on the BS side logic interface 206 : receive a message to be sent through a known BS network address, and the received message must carry a target BS ID and a target proxy network address;
[0063] 2) source network address replacement and source BS ID appending to the message to be sent: obtain a source BS ID from a mapping table according to the received source network address, add the BS ID into a message to be sent, and remove the source network address from the message to be sent, so as to replace the source network address of the BS with this proxy network address;
[0064] 3) the coexistence proxy detection: detect whether the target proxy network address is identical to this proxy, and if the target proxy network address is identical to this proxy, directly perform a coexistent message receiving proxy function on the message sent by this proxy (this function is only provided under the proxy of multiple BSs); and
[0065] 4) sending on the network side logic interface 208 : send a message carrying the target BS ID, the network address of this proxy, and the source BS ID according to the target proxy address.
[0066] 2. Authorized to Receiving Coexistent Message
[0067] 1) receiving on the network side logic interface 208 : receive a coexistent message carrying a source BS ID from a source proxy, and obtain a target BS ID;
[0068] 2) query and replacement of a target address in a received message: obtain a network address corresponding to the BS from a mapping table according to the target BS ID in the received coexistent message, and remove the target proxy network address information in the message; and
[0069] 3) sending on BS side logic interface 206 : send the received message, the source proxy address, and the source BS ID according to the acquired target BS network address.
[0070] Further, the proxy function processing module 202 also may realize the following extended functions:
[0071] 1) determining and reporting/feeding back the working state of a proxy, so as to determine whether the proxy server 200 can work normally or suffers an illegal attack;
[0072] 2) determining and feeding back an abnormal message, so as to determine an illegal BS and an illegal proxy server;
[0073] 3) activating a backup notification;
[0074] 4) reporting an illegal attack message;
[0075] 5) shading an illegal proxy address;
[0076] 6) dynamically updating a mapping table between IDs and network addresses;
[0077] 7) updating an illegal proxy address; and
[0078] 8) negotiating between the proxies.
[0079] FIG. 3 is a flow chart illustrating a method of secure communication through a server acting as a proxy for at least one BS according to an embodiment of the present invention.
[0080] First, a database is built for storing BS address information of the at least one BS and BS ID information corresponding to the BS address information. This step is a preparatory step, and is not shown in FIG. 3 .
[0081] Then, the following steps are performed.
[0082] In Step S 302 , the processing unit 202 adds the BS ID information corresponding to the BS address information of the at least one BS into a first message from the at least one BS.
[0083] In Step S 304 , the BS address information of the at least one BS is replaced by the proxy server address information.
[0084] In Step S 306 , a second message carrying the BS ID information and the proxy server address information is sent to a target address.
[0085] FIG. 4 is a flow chart of a proxy sending process of a proxy server according to the present invention.
[0086] In Step S 402 , a BS side logic interface receives a message to be sent.
[0087] In Step S 404 , a network ID of the BS is queried according to a source BS network address carried in the message to be sent, and then the network ID is filled into the message.
[0088] In Step S 406 , the source BS network address is replaced by the network address of the proxy server.
[0089] In Step S 408 , it is determined whether the target proxy is the current proxy, and if the target proxy is the current proxy, Step S 410 is performed; if the target proxy is not the current proxy, Step S 414 is performed.
[0090] In Step S 410 , a network address of a target BS is queried according to a target BS ID.
[0091] In Step S 412 , a transformed message is sent from the BS side logic interface to the target BS, and the process ends.
[0092] In Step S 414 , the transformed message is sent from a network side logic interface to the proxy of the target BS.
[0093] FIG. 5 is a flow chart of authorized receiving process of a proxy server according to the present invention.
[0094] In Step S 502 , a message is received through a network side logic interface.
[0095] In Step S 504 , a network address of a target BS is queried according to a target BS ID carried in the received message.
[0096] In Step S 506 , the received message is forwarded from a BS side logic interface to the target BS.
[0097] FIG. 6 is a schematic view illustrating connection modes between proxy servers and BSs according to the present invention. As shown in FIG. 6 , BSs A, B, and C and proxy servers p 1 , p 2 and p 3 , corresponding to BSs A, B, C respectively, form a secure communication system. To explain more explicitly, FIG. 6 shows three connection modes between the proxy servers and the BSs, and it should be noted that the modes are given for illustration only instead of limiting the present invention. Moreover, the connection modes between the proxy servers and devices of the BSs are neither limited to the above three interface types.
[0098] In FIG. 6 , the heavy lines represent service channels, and the fine lines represent coexistent message channels.
[0099] 1) The BS A is connected to the proxy p 1 through another device such as a core network device. Thus, a coexistent message network interface and a service channel interface of the BS A may be a public physical interface or two independent interfaces. Besides, the logic interfaces of the proxy p 1 to the BS and to the network may be a public physical interface or independent physical interfaces.
[0100] 2) The BS B is directly connected to the proxy p 2 . Thereby, a coexistent message network interface and a service channel interface of the BS B are independent from each other, and logic interfaces of the proxy p 2 to the BS and to the network are also independent from each other.
[0101] 3) A functional module of the coexistence proxy p 3 is integrated inside the BS C device. Thereby, the BS C provides two physical interfaces outward corresponding to two network addresses for bearing the service channel and coexistent message channel respectively.
[0102] FIGS. 7 a - 7 c are schematic views illustrating corresponding relationships between proxy servers and BSs according to the present invention.
[0103] FIG. 7 a shows a circumstance that each coexistent BS owns one coexistence proxy server. Here, a BS 702 is corresponding to a proxy 704 , and a proxy 706 is corresponding to a BS 708 . A secure communication between the BS 702 and BS 708 is established through the proxy 704 and proxy 706 . Further, the proxy 704 and proxy 706 may be the same proxy server.
[0104] A coexistence proxy may be uniquely corresponding to one coexistent BS. So that, only one entry of BS information, including the BS ID and the BS network address, of the corresponding BS exists in the database. Thus, the BS may integrate the coexistence proxy functional module inside the BS device, and additionally configures coexistent network interfaces independent from the service interfaces. Moreover, the coexistent channels are isolated from the main services channels. In this circumstance, the BS side logic interface of the proxy server is connected to the BS inside the device instead of through a physical interface outside the device. Of course, an independent coexistence proxy device may also be set outside the BS device to serve as an agent for only one BS.
[0105] FIG. 7 b shows a circumstance that multiple coexistent BSs share one coexistence proxy server.
[0106] In FIG. 7 b , multiple BSs 702 share one proxy 704 , and secure communications between the multiple BSs 702 are established through the proxy 704 . Multiple BSs 706 share one proxy 708 , and secure communications between the multiple BSs 704 are established through the proxy 708 . Further, secure connections between the BSs 702 and the BSs 706 are established through the proxies 704 and 708 .
[0107] So that, entries of BS network address, BS ID, and mapping relationship in the proxy database have multiple items, and the coexistence proxy is usually independent of the BSs.
[0108] FIG. 7 c shows a circumstance that one coexistent BS owns multiple coexistence proxy servers.
[0109] Under this circumstance, one BS 702 has multiple proxies 704 , and these proxy servers may perform mutual backup or load sharing. One BS 706 has multiple proxies 708 , and these proxy servers may also perform mutual backup or load sharing.
[0110] FIGS. 8 a - 8 f are examples showing applications of the proxy server according to the present invention. Each figure has a topological graph on the left side and a logic block diagram on the right side.
[0111] FIG. 8 a shows a circumstance that each coexistent BS owns one coexistence proxy. In FIG. 8 a , a coexistence proxy p 1 serves as an agent for transmitting/receiving a coexistent message for a BS A, and a coexistence proxy p 2 serves as an agent for transmitting/receiving a coexistent message for a BS B. The coexistent message transmitted and received by the BS A has to be forwarded by the coexistence proxy p 1 . The coexistent BSs and proxies other than the BS A and the coexistence proxy p 1 do not know the network address of the BS A. The relationship between the BS B and the coexistence proxy p 2 is the same as that between the BS A and the coexistence proxy p 1 . Coexistent message exchanges between the BSs A and B require the coexistent proxies p 1 and p 2 to forward the messages.
[0112] FIG. 8 b shows a circumstance that one coexistence proxy deals with multiple BSs. In FIG. 8 b , a coexistence proxy p 2 serves as an agent for two coexistent BSs B and C. Thereby, coexistent message exchange between the BSs B and C is implemented through the coexistence proxy p 2 , and the coexistence proxy p 1 serves as an agent for the BS A. Coexistent message exchanges between the BSs A and B and that between the BSs A and C require the coexistent proxies p 1 and p 2 to forward the messages.
[0113] FIG. 8 c shows a circumstance that one BS owns multiple proxies. When one BS owns multiple proxies, the network address of one coexistence proxy is usually broadcasted and another coexistence proxy serves as a backup. Once the coexistence proxy in use fails, the communication is switched to another proxy through broadcast to resume the subsequent coexistent message exchange. In addition, multiple coexistent proxies may also be broadcasted at the same time for mutual load sharing and online backup. In FIG. 8 c , coexistent proxies p 1 and p 2 both serve as an agent for a BS A, and a coexistence proxy p 3 serves as an agent for a BS B. Coexistence proxy p 2 is selected to forward the messages exchanged between the BSs A and B.
[0114] FIG. 8 d shows a circumstance of proxy serving multiple BSs on transmitting/receiving coexistent messages. In this circumstance, though multiple BSs share the same proxy, they do not know each other's network address. The coexistence proxy has to serve as an intermediate for coexistent negotiation and to forward coexistent messages between two coexistent BSs, so that the coexistent BSs may not directly acquire the network address of each other in a wired network. As shown in FIG. 8 d , BSs A and B share the same coexistence proxy p 1 .
[0115] FIG. 8 e shows a circumstance where one BS owns multiple proxies and multiple BSs share one proxy. FIG. 8 f shows a circumstance where one proxy serves multiple BSs and each BS is provided with multiple proxies. When one BS owns multiple proxies, the network address of one coexistence proxy is broadcasted and another coexistence proxy serves as a backup. Therefore, once the coexistence proxy in use fails, the communication is switched to another proxy through broadcast to resume the subsequent coexistent message exchange. Meanwhile, multiple coexistent proxies may also be broadcasted for mutual load sharing and online backup. In FIG. 8 e , coexistent proxies p 1 and p 2 both serve as an agent for a BS A, and a coexistence proxy p 3 serves as an agent for a BS B. Coexistence proxy p 2 is selected to forward the messages exchanged between the BSs A and B.
[0116] In view of the above, as the network interface of the BS has to bear data services and related controls, the change of the IP address may cause a lot of negative impacts. However, the coexistence proxy connected to each BS only serves as an agent for transmitting/receiving coexistent signaling, so the change of the network address allocation does not affect the main services of the BS, and multiple proxies may be back up for each other. Meanwhile, as the amount of information to be processed by the coexistence proxy is reduced, its required bandwidth is not high, and thus it has a small probability of crash by attack. Therefore, the coexistence proxy is advantageous in having a simple function and low cost, and multiple proxy backups can be adopted to enhance the reliability.
[0117] When the proxy server receives the coexistent message sent by the BS under its proxy, the proxy server removes the source network address of the BS in the message and adds in its own network address as the source network address. Meanwhile, the proxy server fills in or ensures the BS ID in the message, and sends the transformed message to a target address. When the proxy server receives the coexistent message from a source other than the BS under its proxy, the proxy identifies the coexistent message to be sent to the BS under its proxy according to the BS ID, and then forwards the message to the corresponding BS under its proxy. The coexistence proxy server provided by the present invention is, but not limited to, a functional module integrated in a coexistent BS or an independent coexistence proxy device.
[0118] According to the present invention, the network address of a BS is only restricted in a trusted range instead of being broadcasted in a public network, and thus the probability of attack to the BS in a wired network is reduced.
[0119] When a single proxy crashes by attack, its communication with the LE devices is remained by altering the proxy IP address or activating a backup proxy, so as to avoid interfering the service network of the BS.
[0120] FIG. 9 is a flow chart illustrating a communication method according to an embodiment of the present invention. The method is adopted to achieve secure communication between at least a first BS and a second BS. In addition, the first BS includes at least one first proxy server. As shown in FIG. 9 , the communication method includes the following steps.
[0121] In Step S 902 , the first BS sends a first message to the second BS. The first message includes a first network address of the first proxy server and a first BS ID of the first BS.
[0122] In Step S 904 , the second BS, in response to the first message, sends a contact request message to the first BS according to the first BS ID carried in the first message, and then the first BS, in response to the contact request message, sends a response message to the second BS, so as to achieve secure communication with the second BS.
[0123] FIG. 10 is a flow chart illustrating processes of message exchange corresponding to the communication method in FIG. 9 . As shown in FIG. 10 , the IBS sends over a wireless air interface a network address of a proxy server (also referred to as a proxy) P 1 and a BS ID of the IBS itself to the OBS. On determining that the IBS is a BS sharing mutual trust with the OBS, the OBS sends a request message to the IBS, and the IBS returns a response message to the OBS in response to the request message.
[0124] FIG. 11 is a flow chart illustrating a communication method according to another embodiment of the present invention. The communication method includes the following steps.
[0125] In Step S 1102 , the first BS sends a first message to the second BS. The first message includes a first network address of the first proxy server and a first BS ID of the first BS.
[0126] In Step S 1104 , on receiving the first message, the second BS sends a request message to the first proxy server according to the first network address carried in the first message.
[0127] In Step S 1106 , the first proxy server forwards the request message from the second BS to the first BS.
[0128] In Step S 1108 , in response to the request message forwarded by the first proxy server, the first BS sends a response message to the first proxy server.
[0129] In Step S 1110 , the first proxy server forwards the response message sent from the first BS to the second BS.
[0130] FIG. 12 is a flow chart illustrating a communication method according to yet another embodiment of the present invention. The method is adopted to achieve secure communication between at least a first BS and a second BS. In addition, the first BS includes at least one first proxy server, and the second BS includes at least one second proxy server. As shown in FIG. 12 , the communication method includes the following steps.
[0131] In Step S 1202 , the first BS sends a first message to the second BS. The first message includes a first network address of the first proxy server and a first BS ID of the first BS.
[0132] In Step S 1204 , in response to the first message, the second BS determines whether the first BS is trustworthy according to the first BS ID carried in the first message upon a first condition, and if the first BS is trustworthy, Step S 1206 is performed; the first BS is not trustworthy, Step S 1208 is performed.
[0133] The first condition includes at least one of the following factors: the first BS and the second BS knowing each other's network address, they knowing that they belong to the same operator, they knowing that they are sharing one proxy server, they knowing each other's encrypted public key and that the signature is right, and they knowing the rules of manual configuration. The BS ID may be any identifier that uniquely identifies the first BS, including at least one of a BS identifier, a MAC address of the BS, or a port number of a proxy.
[0134] In Step S 1206 , the second BS sends a contact request message to the first BS, and the first BS, in response to the contact request message, sends a response message to the second BS, so as to achieve secure communication with the second BS, and then the process ends.
[0135] In Step S 1208 , the second BS sends a request message to the first proxy server according to the first network address.
[0136] In Step S 1210 , the first proxy server forwards the request message from the second BS to the first BS.
[0137] In Step S 1212 , the first BS sends a response message to the first proxy server in response to the request message forwarded by first proxy server.
[0138] In Step S 1214 , the first proxy server forwards the response message sent from the first BS to the second BS.
[0139] In the above method, the first BS is an IBS, and the second BS is an OBS.
[0140] FIG. 13 is a flow chart illustrating processes of message exchange corresponding to the communication method according to another embodiment of the present invention. As shown in FIG. 13 , the IBS and the OBS sharing mutual trust can directly exchange messages. The BS in the message received is identified to be a trusted BS by the OBS, and the network address of the IBS can be found in the OBS. Thus, the OBS directly sends a corresponding session request message to the IBS, so that the IBS and the OBS can directly carry out session contact. Different from the flow chart of processes of the message exchange shown in FIG. 3 , the IBS is provided with a proxy P 1 , and sends the network address of the proxy P 1 and the BS ID of the IBS itself to the OBS via the air interface. On determining that the IBS is not a BS sharing mutual trust with the OBS, the OBS sends a request message to the proxy P 1 of the IBS, and the proxy P 1 forwards the request message to the IBS. Then, in response to the request message, the IBS sends a response message to the proxy P 1 , and the proxy P 1 forwards the response message to the OBS.
[0141] FIG. 14 is a flow chart illustrating processes of message exchange corresponding to the communication method according to still another embodiment of the present invention. As shown in FIG. 14 , P 1 is a proxy of an IBS, and P 2 is a proxy of an OBS.
[0142] The IBS broadcasts the address of the coexistence proxy P 1 and the BS ID of itself. Here, the BS ID may be any identifier that can uniquely identify the BS, for example, a fixedly allocated BS identifier, or a MAC address of the BS, or even a port number of a proxy.
[0143] However, when determining that the IBS is not a BS sharing mutual trust on receiving the information, the OBS initiates the communication with the IBS through the proxy of the OBS. The following options exist. When determining that the IBS is a completely trustworthy BS and when a database contains the network address of its counterpart like the same operator or other unified configurations, the OBS may choose to directly communicate with the IBS or communicate with the proxy of the IBS.
[0144] BSs sharing mutual trust are a set of BSs under unified management and recorded with IDs and network addresses of each other in advance. For example, BSs belonging to the same operator share mutual trust. The OBS identifies the BS ID of the IBS to see whether the IBS is trustworthy and also to query the network address of the IBS. The coexistence proxy information is configured before the initialization of the air interface of the IBS, and the coexistence proxy shares mutual trust with the BS. In this embodiment, the proxy keeps the BS network address of the IBS as a secret, and only negotiates with its own network address and the ID of the IBS. In addition, the BS ID is uniquely mapped to the network address of the BS at the proxy.
[0145] When the BS identified in the message received by the OBS is not trusted by this OBS or the network address of the IBS cannot be queried at this OBS, the OBS forwards a corresponding session request message with its own BS ID, the ID of the IBS, and the address of the proxy P 1 to the proxy P 2 of the OBS. The proxy P 2 forwards the session to P 1 according to the address of the proxy P 1 , and P 1 further forwards the message received from P 2 to the IBS according to the ID of the IBS. After the IBS makes a response, the proxy P 1 forwards the session to P 2 , and P 2 further forwards the session to the OBS. In this manner, the required session contact is implemented between the IBS and the OBS.
[0146] On determining that the IBS is trustworthy, the OBS may query the address of the IBS according to the BS ID. The above communication process can be simplified to the process shown in FIG. 8 . In other words, two BSs directly contact without through a proxy.
[0147] FIG. 15 is a flow chart illustrating processes of message exchange corresponding to the communication method according to yet another embodiment of the present invention. On the basis of the embodiment illustrated in FIG. 7 , this embodiment illustrated in FIG. 15 adds a real-time key (RTK) to determine the timeliness of message response, so as to exclude resource negotiation disguised by malicious devices through broadcasting the address of the proxy. Further, if the message broadcast over an air interface is disseminated, the proxy P 1 of the IBS may suffer a large number of attacks. In order to enhance the attack-resistance of the proxy, an RTK is added into the wireless broadcast message of the IBS. The RTK is random data generated by the IBS in real time, and each RTK only has a certain validity period. Due to its randomness and validity, the malicious devices have a difficulty to simulate, and therefore whether a response from the OBS is invalid or not can be determined. As shown in FIG. 15 , the process generally includes the following steps.
[0148] First, during the radio broadcasting of the IBS, the RTK is transferred to the proxy P 1 of the IBS to maintain the effectiveness of the RTK. The contact request fed back by the OBS also needs to return the RTK through transparent transmission. If the RTK in the contact request received by the proxy P 1 of the IBS is a timeout RTK, i.e. an expired RTK, the request is determined as illegal and should be discarded. Therefore, the initial process of contact between the IBS and the OBS through proxies is shown in FIG. 16 . In particular, the proxy P 1 of the IBS requires the request message forwarded by P 2 to be filtered on a timing basis, and the timeout contact request is discarded. Other steps are similar to the above.
[0149] FIG. 16 is a schematic flow chart illustrating processes of an IBS by combining the above embodiments. After broadcasting a message, the IBS waits for a contact request as a response from the OBS in a wired network. The contact request may be received from a known BS or from the local proxy. The IBS needs to transmit the local response to the source of the contact request. Responses from other interfaces or devices are regarded as illegal, and should be discarded. In detail, as shown in FIG. 9 , the process includes the following steps.
[0150] In Step S 1602 , the IBS sends its own proxy address and BS ID through an air interface.
[0151] In Step S 1604 , the IBS receives a wired contact request from the OBS.
[0152] In Step S 1606 , the IBS determines whether the wired contact request comes from a known BS, and if the wired contact request comes from a known BS, Step S 1608 is performed; if the wired contact request does not come from a known BS, Step S 1610 is performed.
[0153] In Step S 1608 , a feedback message is directly sent to the BS, and the process ends.
[0154] In Step S 1610 , it is determined whether the wired contact request comes from a proxy, and if the wired contact request comes from a proxy, Step S 1612 is performed; if the wired contact request does not come from a proxy, Step S 1614 is performed.
[0155] In Step S 1612 , the feedback message is sent by the proxy, and the process ends.
[0156] In Step S 1614 , the wired contact request is determined as an illegal contact request, and is discarded.
[0157] FIG. 17 is a schematic flow chart illustrating processes of an OBS by combining the above embodiments. The OBS processes in different ways depending on the fact whether the BS ID contained in the received message is an ID of a trustworthy BS. When the BS receives through its SS a forwarded and reported message, it is detected whether the BS indicated by the ID contained in the message is trustworthy and recorded with the network address. If the BS indicated by the ID contained in the message is trustworthy and recorded with the network address, the OBS directly communicates with the BS through the network address, or the OBS directly sends a contact request to the IBS through the IBS proxy in the message. If the BS indicated by the ID contained in the message is not trustworthy and recorded with the network address, the OBS may only send a contact request to the IBS to the proxy of the IBS through its own proxy. In detail, the process includes the following steps.
[0158] In Step S 1702 , the OBS receives a report message.
[0159] In Step S 1704 , the OBS obtains the proxy network address and the BS ID of the IBS from the report message.
[0160] In Step S 1706 , the OBS determines whether the IBS is a BS sharing mutual trust with the OBS, and if the IBS is a BS sharing mutual trust with the OBS, Step S 1708 is performed; if the IBS is not a BS sharing mutual trust with the OBS, Step S 1712 is performed.
[0161] In Steps S 1712 to S 1714 , the OBS sends through its own proxy a contact request message to the IBS proxy, and receives feedback message from the proxy of the IBS through the proxy of the OBS, so as to officially contact the IBS. Then, the process ends.
[0162] In Steps S 1708 to S 1710 , the OBS directly sends the contact request message to the network address or proxy of the IBS, and receives a direct feedback message from the IBS, so as to directly contact the IBS.
[0163] As the BS has to bear services, the IP address of the BS must be relatively fixed. However, the coexistence proxy connected to each BS only serves as an agent for transmitting/receiving a coexistent signaling, so the change of the network address allocation has a small impact, and multiple proxies may back up each other. Meanwhile, as the amount of information to be processed by the coexistence proxy is small, its required bandwidth is not high, and thus the probability of crash by attack is reduced. In addition, the RTK mechanism adopted by the present invention further restricts the bandwidth of the illegal signaling.
[0164] Though illustration and description of the present disclosure have been given with reference to exemplary embodiments thereof, it should be appreciated by persons of ordinary skill in the art that various changes in forms and details can be made without deviation from the spirit and scope of this disclosure, which are defined by the appended claims.
|
A proxy server having proxy server address information is provided to serve as an agent for at least one base station to perform secure communication. A method for realizing proxy and secure communication system are also provided to prevent the change of network address allocation from interfering main services of a base station. In addition, a secure communication method between license-exempt devices is provided to ensure the license-exempt devices not to be attacked and to remain at normal work. In the present invention, the network address of a base station is only restricted in a trusted range instead of being broadcasted in a public network, thus reducing the probability of attack to the base station in a wired network.
| 7
|
TECHNICAL FIELD
The present invention relates to a terminal station apparatus, a base station apparatus, a transmission method and a control method.
BACKGROUND ART
3GPP LTE (3rd Generation Partnership Project Long-term Evolution, hereinafter referred to as “LTE”) uplink uses cyclic shift sequences, which are orthogonal sequences, as pilot signals to reduce interference among sequences. A cyclic shift sequence can be generated by cyclically shifting a pilot sequence by a cyclic shift amount on the time axis. For example, FIG. 1 shows a cyclic shift sequence (m=0) and a cyclic shift sequence (m=1) with pilot sequence length N=12 and cyclic shift amount A=6.
In FIG. 1 , while the cyclic shift sequence (m=0) is configured in order of a( 0 ) to a( 11 ), the cyclic shift sequence (m=1) is configured, by cyclically shifting the cyclic shift sequence (m=0) by Δ(=6) samples, in order of a( 6 ) to a( 11 ), a( 0 ) to a( 5 ).
The cyclic shift amount is determined by a base station apparatus (hereinafter abbreviated to “base station”) and reported from the base station to a terminal station apparatus (hereinafter abbreviated to “terminal”) per scheduling (per subframe). Eight types “0, 2, 3, 4, 6, 8, 9, 10” (3 bits) are defined for reporting the cyclic shift amount. These correspond to a cyclic shift amount of “0, 2, 3, 4, 6, 8, 9, 10”×symbol length/12 (ms).
Since sequences can be separated with low inter-sequence interference by assigning cyclic shift sequences of different cyclic shift amounts to different terminals, cyclic shift sequences are used for pilot signal transmission in MU-MIMO (Multiple User-Multiple Input Multiple Output). In MU-MIMO, a plurality of terminals transmit data signals at the same time and the same frequency, spatially multiplex the data signals and thereby improve system throughput. At this time, it is also preferable that a plurality of terminals transmit pilot signals at the same time and the same frequency from the standpoint of frequency utilization efficiency. Therefore, cyclic shift sequences, which are orthogonal sequences, for pilot signals and the cyclic shift sequences are transmitted at the same time and the same frequency. The reception side can separate pilot signals using the nature of orthogonal sequences, and can thereby accurately estimate a channel state of each terminal.
On the other hand, in LTE-Advanced (hereinafter referred to as “LTE-A”) uplink, studies are being carried out on supporting SU-MIMO (Single User-Multiple Input Multiple Output) to improve throughput, whereby one terminal transmits data signals from a plurality of antenna ports at the same time and the same frequency and spatially multiplexes the data signals using virtual communication channels (hereinafter referred to as “streams”) in the space.
Here, the “antenna port” refers to a logical antenna (antenna group) made up of one or a plurality of physical antennas. That is, the antenna port does not always refer to one physical antenna, but may also refer to an array antenna made up of a plurality of antennas. For example, the antenna port may be made up of a plurality of physical antennas and defined as a minimum unit whereby a base station or terminal can transmit different pilot signals. Furthermore, the antenna port may also be defined as a minimum unit for multiplying a weight of a precoding vector. Hereinafter, a case will be described as an example where an “antenna port” and a physical antenna have a one-to-one correspondence for simplicity of explanation.
SU-MIMO requires pilot signals for each stream and studies are being carried out on code-multiplexing pilot signals of each stream using a cyclic shift sequence, which is an orthogonal sequence, for the purpose of reducing inter-sequence interference.
Here, in an ideal environment in which there is no channel variation, a cyclic shift sequence is an orthogonal sequence and no inter-sequence interference occurs. On the other hand, in a real environment with a channel variation, complete orthogonality is not established and a certain degree of inter-sequence interference occurs. Especially when the number of streams increases and the cyclic shift sequence multiplexing number increases, inter-sequence interference also increases. Therefore, in LTE-A, studies are being carried out on reducing inter-sequence interference using a Walsh sequence as well as cyclic shift sequences adopted in LTE.
In multiplexing using Walsh sequences, pilot signals of a first slot (slot # 1 ) and a second slot (slot # 2 ) making up a subframe are multiplied by Walsh sequence w 1 =[1 1] or Walsh sequence w 2 =[1 −1] (see FIG. 2 ). That is, Walsh sequence w 1 uses pilot signals similar to those conventional ones in first and second slots and Walsh sequence w 2 uses pilot signals similar to those conventional ones in the first slot and uses pilot signals with an inverted phase (180 degree rotation) in the second slot.
As a method of reporting a cyclic shift amount, in LTE, the base station reports in three bits using a control information channel (Physical Downlink Control Channel, PDCCH) to be reported to each terminal per scheduling. Furthermore, in LTE-A, studies are being carried out on adding one bit indicating whether a Walsh sequence of each terminal is w 1 or w 2 using a control information channel (PDCCH), the base station reporting the Walsh sequence to each terminal and each terminal switching between the Walsh sequences.
Furthermore, in order to reduce inter-sequence interference of cyclic shift sequences between streams in SU-MIMO, Walsh sequence w 1 is used for pilot signals of odd-numbered streams and Walsh sequence w 2 is used for pilot signals of even-numbered streams (see FIG. 3 ).
Here, the “stream number” is a number indicating order in which data is assigned. For example, when data is transmitted with only one stream, suppose a stream transmitted from one antenna port is stream # 0 and when data is transmitted with two streams, the stream transmitted from an antenna port different from the above-described port is stream # 1 . By setting different Walsh sequences depending on whether a stream number is an odd number or even number, it is possible to reduce inter-sequence interference between pilot signals of neighboring streams (see Non-Patent Literature 1). Furthermore, since there is no need for reporting a bit indicating a Walsh sequence, which will be used in the second (stream # 1 ) and subsequent streams, the amount of reporting the cyclic shift amount can be reduced.
CITATION LIST
Non-Patent Literature
Non-Patent Literature 1: R1-091772: Reference Signal structure for LTE-Advanced UL SU-MIMO, 3GPP TSG RAN WG1 Meeting #57, San Francisco, USA, May 4-8, 2009
SUMMARY OF INVENTION
Technical Problem
However, when simultaneous application of SU-MIMO and MU-MIMO is considered aiming at a further throughput improvement, inter-sequence interference occurs between pilot signals among terminals in addition to inter-sequence interference between a plurality of pilot signals used by the same terminal. For example, as shown in FIG. 4 , when the first terminal (UE (User Equipment)# 1 ) uses Walsh sequence w 1 in a first stream (stream # 0 ) and uses Walsh sequence w 2 in a second stream (stream # 1 ), the second terminal (UE# 2 ) uses Walsh sequence w 1 in the first stream (stream # 0 ), the first stream of the first terminal receives inter-sequence interference from two pilot signals; the second stream of the first terminal and the first stream of the second terminal. Furthermore, as shown in FIG. 5 , when the first terminal and the second terminal have different transmission bandwidths, inter-sequence interference further increases.
For such a situation in which both SU-MIMO and MU-MIMO are applied, the prior art cannot sufficiently reduce inter-sequence interference.
It is an object of the present invention to reduce inter-sequence interference in pilot signals between terminals while suppressing inter-sequence interference in a plurality of pilot signals used by the same terminal even when SU-MIMO and MU-MIMO are simultaneously applied.
Solution to Problem
A terminal station apparatus according to the present invention includes a reception section that receives assignment control information reported with downlink resources, a determining section that determines Walsh sequences of first and second stream groups at least one of which includes a plurality of streams based on the assignment control information; a formation section that forms a transmission signal by spreading each stream included in the first and second stream groups using the determined Walsh sequences and a transmission section that transmits the formed transmission signal, wherein mutually orthogonal Walsh sequences are set in the first and second stream groups respectively and users are assigned in the stream group units.
A base station apparatus according to the present invention includes a control section that sets mutually orthogonal Walsh sequences in first and second stream groups at least one of which includes a plurality of streams and assigns users in the stream group units and a transmission section that transmits assignment control information indicating the Walsh sequence set in the first or second stream group.
A transmission method according to the present invention includes a reception step of receiving assignment control information transmitted with downlink resources, a determining step of determining Walsh sequences of first and second stream groups at least one of which includes a plurality of streams, based on the assignment control information, a forming step of forming a transmission signal by spreading streams included in the first or second stream group using the determined Walsh sequences and a transmission step of transmitting the formed transmission signal, wherein mutually orthogonal Walsh sequences are set in the first and second stream groups respectively and users are assigned in the stream group units.
A control method according to the present invention includes a control step of setting mutually orthogonal Walsh sequences in first and second stream groups, at least one of which includes a plurality of streams and assigning users in the stream group units, and a transmission step of transmitting assignment control information indicating the Walsh sequences set in the first or second stream group.
Advantageous Effects of Invention
According to the present invention, it is possible to reduce inter-sequence interference in pilot signals between terminals while suppressing inter-sequence interference in a plurality of pilot signals used by the same terminal to a low level even when SU-MIMO and MU-MIMO are simultaneously applied.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating a cyclic shift sequence (m=0, 1) when cyclic shift amount Δ=6;
FIG. 2 is a diagram illustrating a multiplexing method using Walsh sequences;
FIG. 3 is a diagram illustrating a correspondence relationship between a stream number and a Walsh sequence;
FIG. 4 is a diagram illustrating inter-sequence interference that occurs between terminals in MU-MIMO;
FIG. 5 is a diagram illustrating inter-sequence interference that occurs between terminals when transmission bandwidths are different in MU-MIMO;
FIG. 6 is a diagram illustrating the applicability in SU-MIMO and MU-MIMO;
FIG. 7 is a diagram illustrating a configuration of a base station according to Embodiment 1 of the present invention;
FIG. 8 is a diagram illustrating an example of a correspondence relationship between a stream number and a Walsh sequence;
FIG. 9 is a diagram illustrating a configuration of a terminal according to Embodiment 1;
FIG. 10 is a diagram illustrating another example of a correspondence relationship between a stream number and a Walsh sequence;
FIG. 11 is a diagram illustrating an example of a correspondence relationship between a stream number and a cyclic shift amount;
FIG. 12 is a diagram illustrating an example of an operating sequence identification table;
FIG. 13 is a diagram illustrating another example of an operating sequence identification table;
FIG. 14 is a diagram illustrating further candidates for pairs of a cyclic shift amount and a Walsh sequence;
FIG. 15 is a diagram illustrating advantages when an interval between cyclic shift amounts in first and second streams is set to a maximum;
FIG. 16 is a diagram illustrating candidates for pairs of a cyclic shift amount and a Walsh sequence;
FIG. 17 is a diagram illustrating other candidates for pairs of a cyclic shift amount and a Walsh sequence;
FIG. 18 is a diagram illustrating still further candidates for pairs of a cyclic shift amount and a Walsh sequence;
FIG. 19 is a diagram illustrating still further candidates for pairs of a cyclic shift amount and a Walsh sequence;
FIG. 20 is a diagram illustrating an example of a correspondence relationship between a stream number and a cyclic shift amount;
FIG. 21 is a diagram illustrating another example of an operating sequence identification table according to Embodiment 3; and
FIG. 22 is a diagram illustrating a correspondence relationship between a cyclic shift amount and a Walsh sequence set in second to fourth streams.
DESCRIPTION OF EMBODIMENTS
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
(Embodiment 1)
Viewpoints of the present invention will be described first, before describing a more specific configuration and operation of an embodiment.
In SU-MIMO, one terminal simultaneously transmits data signals using a plurality of streams. Here, suppose “streams” are signals transmitted from antenna ports associated with data signals or pilot signals (or communication channel in the space). Streams are also called “layers.” Furthermore, in vectors (precoding vectors) used for weight control under study for demodulation pilot signals on an LTE-A uplink, streams and precoding vectors are associated in a one-to-one correspondence.
On the other hand, in MU-MIMO, a plurality of terminals transmit data signals with one or a plurality of streams simultaneously.
At this time, in SU-MIMO, inter-sequence interference of pilot signals increases as the number of streams per terminal increases, while in MU-MIMO, inter-sequence interference of pilot signals increases as the number of streams per terminal or the number of spatially multiplexed terminals increases.
Therefore, in a situation in which both the number of streams per terminal and the number of spatially multiplexed terminals are large, inter-signal interference of data signals and pilot signals increases and the error rate deteriorates considerably. Therefore, the possibility that such a situation may be used in a real environment is low (see FIG. 6 ) and even if performance is improved for such a situation, contribution of the amount of performance improvement to the entire system is considered small.
Furthermore, in LTE-A uplink, studies are being carried out on SU-MIMO transmission using four antennas for transmission and reception respectively as a spatial multiplexing number which can be realized in a real environment, that is, MIMO transmission having a maximum number of streams of 4. Based on SU-MIMO, a maximum number of streams of 4 is likewise a spatial multiplexing number that can be realized in a real environment also in MU-MIMO transmission. Therefore, a case will be studied below as an example where the number of streams per terminal in SU-MIMO is a maximum of 4 or less or the total number of streams per terminal in MU-MIMO is 4 or less.
[Configuration of Base Station Apparatus]
FIG. 7 is a diagram illustrating a configuration of base station 100 according to the present embodiment.
Coding section 101 receives transmission data (downlink data), a response signal (ACK/NACK signal) inputted from error detection section 117 , resource assignment information of each terminal inputted from scheduling section 109 , control information indicating MCS (Modulation Coding Scheme) or the like, weight control information for controlling transmission power/weight, information on cyclic shift amounts, information indicating a correspondence relationship between a cyclic shift amount (or stream number) and a Walsh sequence or the like as input. Information on the correspondence relationship between a stream number and a Walsh sequence will be described later.
Assignment control information is composed of a response signal, resource assignment information, control information, weight control information, information on cyclic shift amounts, information on the correspondence relationship between a stream number and a Walsh sequence or the like. Coding section 101 codes the transmission data and assignment control information and outputs the coded data to modulation section 102 . The information on the cyclic shift amount, assignment control information including information indicating the correspondence relationship between a stream number and a Walsh sequence are transmitted per scheduling from RF (Radio Frequency) transmission section 103 , which will be described later.
Modulation section 102 modulates the coded data inputted from coding section 101 and outputs the modulated signal to RF transmission section 103 .
RF transmission section 103 applies transmission processing such as D/A (Digital to Analog) conversion, up-conversion, amplification to the signal inputted from modulation section 102 and transmits by radio the signal subjected to the transmission processing from one or more antennas to each terminal.
RF reception section 104 applies reception processing such as down-conversion, A/D (Analog to Digital) conversion to a signal received via an antenna from each terminal and outputs the signal subjected to the reception processing to separation section 105 .
Separation section 105 separates the signal inputted from RF reception section 104 into a pilot signal and a data signal. Separation section 105 outputs the pilot signal to DFT (discrete Fourier transform) section 106 and outputs the data signal to DFT section 111 .
DFT section 106 applies DFT processing to the pilot signal inputted from separation section 105 and converts the signal from a time-domain signal to frequency-domain signal. DFT section 106 then outputs the pilot signal converted to the frequency-domain signal to demapping section 107 .
Demapping section 107 extracts a pilot signal of a portion corresponding to a transmission band of each terminal from the frequency-domain pilot signal inputted from DFT section 106 . Demapping section 107 then outputs each extracted pilot signal to estimation section 108 .
Estimation section 108 determines a sequence of pilot signals received, based on a cyclic shift amount and a Walsh sequence (w 1 or w 2 ) inputted from pilot information determining section 110 as information on the sequence of pilot signals.
Furthermore, estimation section 108 extracts a desired pilot signal from the pilot signals inputted from demapping section 107 using information on the sequence of the pilot signals and acquires estimate values by estimating a frequency-domain channel state (channel frequency response) and reception quality. Estimation section 108 then outputs the estimate value of the channel frequency response to signal separation section 113 and outputs the estimate value of the reception quality to scheduling section 109 .
Scheduling section 109 schedules assignment of a transmission signal transmitted by each terminal to a transmission band (frequency resource) according to the estimate value of the reception quality inputted from estimation section 108 . Scheduling section 109 also determines transmission power/weight of the transmission signal transmitted by each terminal. Scheduling section 109 outputs assignment control information (e.g., resource assignment information, control information) indicating the scheduling result and weight control information for controlling transmission power/weight to coding section 101 and outputs resource assignment information to pilot information determining section 110 .
Pilot information determining section 110 determines a transmission band of a pilot signal, based on the resource assignment information inputted from scheduling section 109 . Furthermore, pilot information determining section 110 stores a plurality of correspondence relationships between a stream number and a Walsh sequence and selects a correspondence relationship between a stream number and a Walsh sequence that can reduce inter-sequence interference between pilot signals from among the plurality of correspondence relationships.
FIG. 8 is a diagram illustrating an example of a correspondence relationship between a stream number and a Walsh sequence stored in pilot information determining section 110 . In the example shown in FIG. 8 , two patterns; pattern A and pattern B are shown as the correspondence relationship between a stream number and a Walsh sequence. Pilot information determining section 110 assigns, in the case of MU-MIMO, for example, pattern A and pattern B to a terminal to be multiplexed and outputs information indicating a correspondence relationship between a stream number indicating pattern A or pattern B and a Walsh sequence to estimation section 108 and coding section 101 . Since different Walsh sequences are associated with the same stream number in pattern A and pattern B, it is possible to reduce inter-sequence interference between terminals by assigning pattern A and pattern B to each terminal.
Furthermore, pilot information determining section 110 determines a cyclic shift amount of each cyclic shift sequence capable of reducing inter-sequence interference between pilot signals in addition to the correspondence relationship. Pilot information determining section 110 assigns a cyclic shift sequence having a large difference in the cyclic shift amount capable of reducing inter-sequence interference to each stream. Pilot information determining section 110 then outputs information regarding the determined cyclic shift amount of the cyclic shift sequence to estimation section 108 and coding section 101 .
On the other hand, DFT section 111 applies DFT processing to the data signal inputted from separation section 105 and converts the data signal from a time-domain signal to a frequency-domain signal. DFT section 111 outputs the data signal converted to the frequency-domain signal to demapping section 112 .
Demapping section 112 extracts a data signal of a portion corresponding to the transmission band of each terminal from the signal inputted from DFT section 111 . Demapping section 112 then outputs the each extracted signal to signal separation section 113 .
Signal separation section 113 weights and combines the data signals inputted from demapping section 112 according to transmission power/weight using the estimate value of the channel frequency response inputted from estimation section 108 and thereby separates the data signal into data signals of the respective streams. Signal separation section 113 then outputs the data signals subjected to equalization processing to IFFT (Inverse Fast Fourier Transform) section 114 .
IFFT section 114 applies IFFT processing to the data signals inputted from signal separation section 113 . IFFT section 114 then outputs the signal subjected to the IFFT processing to demodulation section 115 .
Demodulation section 115 applies demodulation processing to the signal inputted from IFFT section 114 and outputs the signal subjected to the demodulation processing to decoding section 116 .
Decoding section 116 applies decoding processing to the signal inputted from demodulation section 115 and outputs the signal subjected to the decoding processing (decoded bit sequence) to error detection section 117 . Error detection section 117 performs error detection on the decoded bit sequence inputted from decoding section 116 . For example, error detection section 117 performs error detection using a CRC (Cyclic Redundancy Check).
Error detection section 117 generates, when an error is detected in the decoded bit as a result of error detection, a NACK signal as a response signal, and generates, when no error is detected in the decoded bit, an ACK signal as a response signal. Error detection section 117 then outputs the response signal generated to coding section 101 . Furthermore, when no error is detected in the decoded bit, error detection section 117 outputs the data signal as the received data.
[Configuration of Terminal Station Apparatus]
FIG. 9 is a diagram illustrating terminal 200 according to the present embodiment.
RF reception section 201 applies reception processing such as down-conversion, A/D conversion to a signal from the base station received via an antenna and outputs the signal subjected to the reception processing to demodulation section 202 .
Demodulation section 202 applies equalization processing and demodulation processing to the signal inputted from RF reception section 201 and outputs the signal subjected to the processing to decoding section 203 .
Decoding section 203 applies decoding processing to the signal inputted from demodulation section 202 and extracts received data and assignment control information from the signal subjected to the decoding processing. Here, the assignment control information includes a response signal (ACK signal/NACK signal), resource assignment information, control information, weight control information, information on cyclic shift amounts and information indicating a correspondence relationship between a stream number and a Walsh sequence. Of the extracted assignment control information, decoding section 203 outputs the resource assignment information and control information to coding section 207 , modulation section 208 and assignment section 209 and outputs the weight control information to transmission power/weight control section 211 and outputs the information regarding the cyclic shift amounts and information indicating the correspondence relationship between a stream number and a Walsh sequence to pilot information determining section 204 .
Pilot information determining section 204 stores a plurality of correspondence relationships (patterns) between a stream number and a Walsh sequence and determines the correspondence relationship between a stream number and a Walsh sequence, based on the information indicating the correspondence relationship between a stream number and a Walsh sequence inputted from decoding section 203 . The information indicating the correspondence relationship between a stream number and a Walsh sequence is not limited to information reporting pattern A or pattern B, but may be information indicating whether the Walsh sequence used in stream 0 is w 1 or w 2 .
For example, when pattern A and pattern B as shown in FIG. 8 as the correspondence relationship between a stream number and a Walsh sequence are stored, pilot information determining section 204 determines a Walsh sequence used for each stream, based on information indicating the correspondence relationship (information on pattern A or pattern B) inputted from decoding section 203 .
Furthermore, pilot information determining section 204 determines the cyclic shift amounts of the cyclic shift sequence according to the information on the cyclic shift amounts inputted from decoding section 203 . Pilot information determining section 204 then outputs the determined information to pilot signal generation section 205 .
Pilot signal generation section 205 generates a pilot signal based on the information on the cyclic shift amounts and Walsh sequences inputted from pilot information determining section 204 and outputs the pilot signal to multiplexing section 210 . To be more specific, pilot signal generation section 205 spreads the cyclic shift sequence according to the cyclic shift amount set by pilot information determining section 204 using the Walsh sequence set by pilot information determining section 204 and outputs the spread signal to multiplexing section 210 .
CRC section 206 receives divided transmission data as input. CRC section 206 performs CRC coding on the inputted transmission data to generate CRC coded data and outputs the generated CRC coded data to coding section 207 .
Coding section 207 codes the CRC coded data inputted from CRC section 206 using the control information inputted from decoding section 203 and outputs the coded data to modulation section 208 .
Modulation section 208 modulates the coded data inputted from coding section 207 using the control information inputted from decoding section 203 and outputs the modulated data signal to assignment section 209 .
Assignment section 209 assigns the data signal inputted from modulation section 208 to frequency resources (RBs), based on the resource assignment information inputted from decoding section 203 . Assignment section 209 outputs the data signal assigned to RBs to multiplexing section 210 .
Multiplexing section 210 time-multiplexes the data signal and the pilot signal inputted from assignment section 209 and outputs the multiplexed signal to transmission power/weight control section 211 .
Transmission power/weight control section 211 determines transmission power/weight based on the weight control information inputted from decoding section 203 , multiplies each multiplexed signal inputted from multiplexing section 210 by the transmission power/weight and outputs the multiplexed signal after the multiplication to RF transmission section 212 .
RF transmission section 212 applies transmission processing such as D/A conversion, up-conversion, amplification to the multiplexed signal inputted from transmission power/weight control section 211 and transmits by radio the signal after the transmission processing to the base station from an antenna.
Next, the correspondence relationship between a stream number and a Walsh sequence will be described.
Here, in SU-MIMO, since one terminal transmits a plurality of streams, the same transmission bandwidths (bandwidths for transmitting data signal) of the respective streams are set to the same value. This is because the amount of reporting control information of resource assignment can be reduced by setting the same transmission bandwidth for one terminal. Thus, in SU-MIMO since the transmission bandwidth is common among sequences, it is possible to maintain orthogonality among sequences through the cyclic shift sequences, provides a high effect of reducing inter-sequence interference and produces less inter-sequence interference.
On the other hand, in MU-MIMO, a transmission bandwidth is reported to each terminal, and each terminal can thereby set a different transmission bandwidth and set a transmission bandwidth adapted to a channel situation of each terminal. Therefore, when transmission bandwidths are different among sequences, the cyclic shift sequence alone cannot maintain orthogonality among sequences, provides a lower effect of inter-sequence interference and produces large inter-sequence interference.
Therefore, hereinafter the number of terminals in MU-MIMO is assumed to be two in agreement with the number of terminals that can be generated with a Walsh sequence of a sequence length of 2 (length that can be realized in an LTE subframe configuration). Furthermore, a case will be assumed where each Walsh sequence is associated with two streams (=maximum number of streams/number of Walsh sequences under study in LTE-A) so that inter-sequence interference can be suppressed to a low level from the standpoint including inter-sequence interference in SU-MIMO in addition to MU-MIMO. An appropriate correspondence relationship between a stream number and a Walsh sequence in this case will be studied.
In the present embodiment, terminals are configured to use mutually orthogonal Walsh sequences in MU-MIMO. The Walsh sequence can maintain orthogonality even when transmission bandwidths are different among sequences.
FIG. 8 is a diagram illustrating an example of correspondence between a stream number and a Walsh sequence. In MU-MIMO having two or fewer streams to be assigned to each terminal, it is possible to use Walsh sequences differing among terminals, and thereby maintain orthogonality among sequences. As described above, the stream number is a number indicating the order in which data is assigned.
When the example of correspondence shown in FIG. 8 is used, in pattern A, Walsh sequence w 1 is set in a first stream group made up of a first stream (stream # 0 ) and second stream (stream # 1 ) and Walsh sequence w 2 is set in a second stream group made up of a third stream (stream # 2 ) and fourth stream (stream # 3 ). On the other hand, in pattern B, Walsh sequence w 2 is set in the first stream group and Walsh sequence w 1 is set in the second stream group.
Here, as one method, each terminal determines a pattern based on control information of pattern A or pattern B and in SU-MIMO, the first stream group and second stream group in the determined pattern are assigned to the terminal. In MU-MIMO, the first stream group in the determined pattern is assigned to the first terminal and the second stream group is assigned to the second terminal. Thus, mutually orthogonal Walsh sequences are set in the first and second stream groups at least one of which includes a plurality of streams and users are assigned in stream group units.
Furthermore, as another method, each terminal determines a pattern based on control information of pattern A or pattern B, and when the number of streams used by the terminal for data transmission is equal to or fewer than the number of streams included in the first stream group, each terminal uses only the sequence assigned to the first stream group in the determined pattern, whereas when the number of streams is greater than the number of streams included in the stream group, each terminal uses the sequences assigned to the first and second stream groups.
That is, when the correspondence relationship between a stream number and a Walsh sequence as shown in FIG. 8 is used, pilot information determining section 204 determines to use a Walsh sequence (w 1 or w 2 ) reported from the base station for the first stream, determines to use the same Walsh sequence as the Walsh sequence of the first stream for the second stream, and determines to use a Walsh sequence different from the first and second streams in the third and fourth streams.
As the number of streams increases, the separation performance generally deteriorates a great deal, but in SU-MIMO, if the number of streams per terminal is 2 or less, streams can be separated using only cyclic shift sequences while using the same Walsh sequence, and therefore performance deterioration is small.
Thus, when mutually orthogonal Walsh sequences are set in the first and second stream groups, the first and second stream groups where mutually orthogonal Walsh sequences are assigned may be configured of two streams also for the following reasons.
As described above, in LTE-A uplink, as SU-MIMO, studies are being carried out on MIMO transmission with four antennas for transmission and reception respectively, that is, assuming that the maximum number of streams is four. Therefore, if the number of streams included in each stream group is assumed to be 2, Walsh sequences w 1 and w 2 are associated with two streams each.
Using two cyclic shift sequences corresponding to the maximum difference between the respective cyclic shift amounts in each stream group makes it possible to reduce inter-sequence interference that occurs between streams. Therefore, when the maximum number of streams in MIMO transmission is four, it is ensured that each stream group includes two (=maximum number of streams/Walsh sequences under study in LTE-A) streams. Thus, assigning different Walsh sequences to the respective stream groups makes it possible to reduce inter-sequence interference occurring between streams.
As a result, when SU-MIMO and MU-MIMO are simultaneously applied, it is possible to reduce inter-sequence interference in pilot signals between terminals while suppressing inter-sequence interference in a plurality of pilot signals used by the same terminal to a low level.
It is also assumed in MU-MIMO transmission that the first terminal uses three streams and the second terminal uses one stream.
Thus, the number of streams N w making up each stream group for assigning mutually orthogonal different Walsh sequences is shared between the base station and terminal. Pilot information determining section 204 may also determine to use a Walsh sequence (w 1 or w 2 ) reported from the base station in the first to N w -th streams and use a Walsh sequence different from the Walsh sequence reported by the base station in the (N w +1)-th and subsequent streams. In other words, one terminal station may use one type of Walsh sequence (w 1 or w 2 ) in the first to N w -th streams and use one type of Walsh sequence different from the above-described Walsh sequence in the (N w +1)-th and subsequent streams. Whether the first stream is w 1 or w 2 may be directly reported by the base station or indirectly reported as information of pattern A or pattern B. For example, when two streams are assigned to the terminal, N w =2 may be shared between the base station and terminal, and when three streams are assigned to the terminal, N w =3 may be shared between the base station and terminal.
Thus, the correspondence relationship (pattern) between a stream number and a Walsh sequence is changed according to N w so as to use, for example, the correspondence relationship in FIG. 8 when N w =2, and use the correspondence relationship in FIG. 10 when N w =3. When the number of streams is four and N w =4 is assumed, the same Walsh sequence is used in all streams.
The N w value corresponding to the number of streams of each terminal in MU-MIMO may be reported through signaling. At this time, in SU-MIMO, the same Walsh sequence as that of the first stream is used in the first to N w -th streams and a Walsh sequence different from the Walsh sequence of the first stream is used in the (N w +1)-th and subsequent streams. This allows the number of streams using the same Walsh sequence to be arbitrarily changed. Furthermore, the above-described technique and the conventional technique ( FIG. 3 ) may be changed through signaling.
Also when the first terminal uses three streams and the second terminal uses one stream, mutually orthogonal Walsh sequences w 1 and w 2 are set for the first stream group made up of three streams and for the second stream group made up of one stream group. Assigning the first stream group to the first terminal and assigning the second stream group to the second terminal causes the first terminal and the second terminal to use different Walsh sequences, which reduces inter-sequence interference between terminals. Furthermore, assigning the first stream group of pattern A to the first terminal and assigning the first stream group of pattern B to the second terminal causes the first terminal and the second terminal to use different Walsh sequences, which reduces inter-sequence interference between terminals. Thus, when MU-MIMO where the number of streams of each terminal is three or more is assumed, it is possible to reduce inter-sequence interference between terminals using a Walsh sequence similar to that of the first stream also for the Walsh sequence used for the third stream.
Examples of the signaling method for changing N w include (a) a method of reporting per scheduling, and (b) a method of reporting at a longer interval than scheduling (Higher Layer Signaling or the like).
Furthermore, N w may be reported in a terminal-specific (UE Specific) manner or may be reported in a cell-specific (Cell Specific) manner. Furthermore, N w may be reported implicitly according to the number of the cyclic shift amount. For example, when “0, 2, 3, 4, 6, 8, 9, 10” (that is, “0, 2, 3, 4, 6, 8, 9, 10”×symbol length/12 (ms)) is defined as the cyclic shift amount reported from the base station to the terminal, if any one of cyclic shift amounts “0, 2, 3, 4” is reported, N w =2 is assumed and if any one of cyclic shifts “6, 8, 9, 10” is reported, N w =4 is assumed.
For example, when N w =2, mutually orthogonal Walsh sequences w 1 and w 2 are set for the first stream group made up of two streams and for the second stream group made up of two stream groups. Furthermore, when N w =4, mutually orthogonal Walsh sequences w 1 and w 2 are set for the first stream group made up of four streams and for the second stream group made up of 0 stream groups. Then, N w is changed explicitly or implicitly. That is, the terminal transmits pilot signals of four streams using two types w 1 and w 2 when N w =2 and transmits pilot signals of four streams using any one of w 1 and w 2 when N w =4. In other words, Walsh sequences of the same sign are used for the first stream and second stream and Walsh sequences of the same sign as or different sign from that of the first stream depending on the number of streams N w making up each stream group in the third and subsequent streams.
Thus, the N w value can be changed through signaling, and it is thereby possible to use the number of streams N w set according to the separation performance of spatially multiplexed signals in MU-MIMO and flexibly reduce inter-sequence interference.
In the above description, a Walsh sequence is associated with a stream number, but a cyclic shift amount can also be associated with a stream number in addition to a Walsh sequence. For example, as shown in FIG. 11 , cyclic shift sequences (here, suppose “0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11” (that is, “0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11”×symbol length/12 (ms)) are selectable as the cyclic shift amounts) having a large difference in cyclic shift amounts is assigned to the same Walsh sequence.
To be more specific, when cyclic shift amount Δ 0 (Δ 0 <12) used for the first stream (stream # 0 ) is reported from the base station, cyclic shift amount Δ 1 used for the second stream (stream # 1 ) is assumed to be (Δ 0 +6)mod12 and the cyclic shift amount is assumed to be a ½ symbol length (see pattern 1 and pattern 2 in FIG. 11 ). Furthermore, suppose cyclic shift amount Δ 2 used for the third stream (stream # 2 ) is (Δ 0 +3)mod12, the cyclic shift amount is a ¼ symbol length, cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) is (Δ 0 +9)mod12 and the cyclic shift amount is a ¾ symbol length (see pattern 1 in FIG. 11 ). Cyclic shift amount Δ 2 used for the third stream (stream # 2 ) may be (Δ 0 +9)mod12 and cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) may be (Δ 0 +3)mod12 (see pattern 2 in FIG. 11 ).
This allows the difference in the cyclic shift amount to be a ½ symbol length not only between sequences using Walsh sequence w 1 but also between sequences using Walsh sequence w 2 and also allows the difference in the cyclic shift amount to be largest, and thereby allows inter-sequence interference to be drastically reduced. On the other hand, the difference in the cyclic shift amount is set to a ¼ symbol length between different Walsh sequences (w 1 and w 2 ) to thereby reduce inter-sequence interference in cyclic shift sequences and further reduce inter-sequence interference in different Walsh sequences.
Thus, when the sum of the number of streams per terminal in SU-MIMO and the number of streams of the terminals in MU-MIMO (hereinafter referred to as “number of operating streams”) is four, inter-sequence interference can be drastically reduced using “0, 6, 3, 9” (or “0, 6, 9, 3”) as the amount of offset of the cyclic shift amount for the first to fourth streams.
When the number of operating streams is three, “0, 6, 3” or “0, 4, 8” may be used as the amount of offset of the cyclic shift amount for the first to third streams. Here, the amount of offset “0, 6, 3” is partially common to the amount of offset “0, 6, 3, 9” applicable to the case where the number of operating streams is four. Therefore, when the number of operating streams is three, it is possible to use part of the processing in the case where the number of operating streams is four by using “0, 6, 3” as the amount of offset of the cyclic shift amount. That is, since the same circuit can be used in the cases where the number of operating streams is three and four, the circuit scale can be reduced. However, when “0, 6, 3” is used as the amount of offset of the cyclic shift amount, the interval of cyclic shift amounts between streams is three. On the other hand, when the number of operating streams is three, if “0, 4, 8” is used as the amount of offset of the cyclic shift amount, the interval of cyclic shift amounts between streams is four and the interval of cyclic shift amounts can be widened to a maximum degree. Therefore, when the number of operating streams is three, using “0, 4, 8” as the amount of offset of the cyclic shift amount has a greater effect of reducing inter-sequence interference than using “0, 6, 3.”
As described above, pilot information determining section 204 determines respective Walsh sequences of the first and second stream groups, at least one of which includes a plurality of streams, based on assignment control information and pilot signal generation section 205 spreads each stream included in the first and second stream groups with the determined Walsh sequence and thereby forms a transmission signal. At this time, mutually orthogonal Walsh sequences are set in the first and second stream groups and users are assigned in stream group units.
MODIFICATION EXAMPLE 1
A case has been described above where in MU-MIMO transmission, Walsh sequence w 1 is assigned to the first stream group made up of first to third streams and Walsh sequence w 2 is assigned to the second stream group made up of only the fourth stream as an example of N w =3.
In this case, in SU-MIMO, the same Walsh sequence w 1 is assigned to the first to third streams included in the first stream group, and it is therefore necessary to reduce interference between three sequences using cyclic shift sequences. However, even when N w =3, since the difference in the cyclic shift amount between cyclic shift sequences is sufficiently large, inter-sequence interference can be sufficiently reduced.
Thus, in SU-MIMO, even when the same transmission bandwidth is used between sequences, the difference in the cyclic shift amount between cyclic shift sequences decreases as the number of streams increases and inter-sequence interference between cyclic shift sequences increases. That is, in SU-MIMO, when the number of streams making up a stream group is small, the difference in the cyclic shift amount can be increased and therefore even when the same Walsh sequence is used, inter-sequence interference can be sufficiently reduced only with cyclic shift sequences, whereas when the number of streams making up the stream group is large, the difference in the cyclic shift amount decreases and inter-sequence interference between sequences increases.
Thus, in SU-MIMO, when the number of streams of a stream group is small, Walsh sequences of the same sign are applied and when the number of streams of the stream group is large, Walsh sequences of the same sign or a different sign may also be applied. To be more specific, in SU-MIMO, Walsh sequence w 1 or w 2 is applied when the number of streams of a stream group is two or fewer, whereas when the number of streams of a stream group is three or more, Walsh sequences w 1 and w 2 are applied. When the number of streams per terminal is three or more, the first stream group to which Walsh sequence w 1 is assigned and the second stream group to which Walsh sequence w 2 is assigned are assigned to a single user. That is, in this case, the first and second stream groups for which mutually orthogonal Walsh sequences are set are assigned to a single user.
A case has been described above where the number of streams is four or fewer as an example, but it may also be assumed that the correspondence relationship in the first and subsequent streams is repeated in the fifth and subsequent streams. That is, a Walsh sequence of w 1 may be used in the first and fifth streams, the second and sixth streams,
The base station and terminal according to the present invention may also be replaced by the following.
The base station includes pilot information determining section 110 as a setting section that classifies a stream defined in one terminal into a first stream group and a second stream group, and selects and sets a sequence used in the first stream group and the second stream group from a first Walsh sequence or second Walsh sequence for each terminal, pilot information determining section 110 as a control information generation section that generates control information indicating whether the sequence used in the set first stream group is the first Walsh sequence or the second Walsh sequence, and RF transmission section 103 as a transmission section that transmits the control information, wherein pilot information determining section 110 as the setting section assigns different Walsh sequences to the first stream group and the second stream group in each terminal.
The terminal includes RF reception section 201 as a reception section that classifies a stream defined in one terminal into a first stream group and a second stream group, and receives control information indicating whether a sequence used in the first stream group is a first Walsh sequence or a second Walsh sequence, demodulation section 202 and decoding section 203 , pilot information determining section 204 as a setting section that assigns a sequence reported by the control information to the first stream group and assigns a sequence different from the sequence reported by the control information to the second stream group based on the control information, pilot signal generation section 205 as a formation section that forms a transmission signal using the set Walsh sequence and RF transmission section 212 as a transmission section that transmits the formed transmission signal, where pilot signal generation section 205 as the formation section: uses only the sequence assigned to the first stream group when the number of streams used by the terminal for data transmission is equal to or fewer than the number of streams included in the first stream group; and uses the sequence assigned to the first and second stream groups, when the number of streams is greater than the number of streams included in the stream group.
(Embodiment 2)
Embodiment 1 assumes that information on the correspondence relationship between a stream number and a Walsh sequence and information on the cyclic shift sequences are reported per scheduling. To be more specific, in LTE, the base station selects a cyclic shift amount of each cyclic shift sequence from among eight types (cyclic shift amounts defined in LTE) and reports the selected cyclic shift amount to the terminal using three bits. Furthermore, in LTE-A, studies are being carried out on a base station selecting any one of w 1 and w 2 as a Walsh sequence and reporting the selected sequence to the terminal using one bit.
Therefore, according to Embodiment 1, the terminal selects a cyclic shift sequence and a Walsh sequence from among 16 types of combinations; eight types of cyclic shift sequences and two types of Walsh sequences. However, in a real environment of LTE-A uplink, the number of streams assumed as the number of streams used in SU-MIMO or MU-MIMO is four at most and it is sufficient that four sequences having little inter-sequence interference be able to be selected as pilot signals. With all these aspects taken into consideration, there are many alternatives (16 types) in selecting a pilot signal sequence with respect to the number of sequences to be code-multiplexed (four types at most).
That is, in consideration of the necessity for providing only four sequences as sequences with less inter-sequence interference, influences of pilot signals on inter-sequence interference are small even when alternatives (degree of freedom) of pilot signals are reduced. In other words, it may be considered unnecessary such flexibility (degree of freedom) that both cyclic shift sequences and Walsh sequences are reported to each terminal per scheduling.
On the other hand, in MU-MIMO, terminals to be spatially multiplexed differ from one scheduling instance to another. Therefore, it is preferable that in MU-MIMO, different Walsh sequences be able to set per scheduling and spatial multiplexing be able to be performed between different terminals per scheduling. In other words, it is preferable that Walsh sequences be able to be adjusted with information reported from the base station per scheduling.
Thus, the present embodiment associates a Walsh sequence with a cyclic shift amount of each cyclic shift sequence used for a first stream and changes a correspondence relationship (pattern) indicating a pair of the cyclic shift amount and Walsh sequence at an interval longer than that of scheduling. That is, the base station reports a cyclic shift amount per scheduling and reports a correspondence relationship (pattern) indicating a pair of a cyclic shift amount and a Walsh sequence at an interval longer than that of scheduling. This causes a reception cycle of a correspondence relationship (pattern) indicating a pair of a cyclic shift amount and a Walsh sequence in the terminal to be longer than a reception cycle of a cyclic shift amount, and can thereby suppress increases in the amount of reporting of Walsh sequences. Furthermore, since the terminal can set Walsh sequence w 1 or w 2 according to information on the cyclic shift amount reported from the base station per scheduling, it is possible to suppress increases in the amount of reporting of Walsh sequences while maintaining the degree of freedom within which Walsh sequences can be changed per scheduling.
The above-described correspondence relationship may be reported in a manner that differs from one cell to another (cell-specific) or may be reported in a manner that differs from one terminal to another (user specific). In the case of cell-specific reporting, only information common to respective terminals in the cell needs to be reported, and it is thereby possible to reduce the amount of reporting. On the other hand, in the case of user-specific reporting, since association of cyclic shift sequences and Walsh sequences can be set for each terminal, flexibility of sequences assigned to each terminal increases. For example, when a correspondence relationship in which w 1 is associated with a cyclic shift sequence of cyclic shift amount 2 is used for the first terminal, and a correspondence relationship in which w 2 is associated with a cyclic shift sequence of cyclic shift amount sequence 2 is used for the second terminal, it may be possible to assign cyclic shift sequence 2 to the first and second terminals and perform code multiplexing using Walsh sequences w 1 and w 2 . Furthermore, in this case, it is also possible to reduce the amount of reporting used to report Walsh sequences compared to the prior art that reports Walsh sequences to each terminal.
The configuration of the base station according to Embodiment 2 of the present invention is similar to the configuration of Embodiment 1 shown in FIG. 7 and is different only in some functions, and therefore only different functions will be described using FIG. 7 .
Pilot information determining section 110 stores an operating sequence identification table storing a plurality of candidates for pairs of a cyclic shift amount and a Walsh sequence.
FIG. 12 is a diagram illustrating an example of the operating sequence identification table according to the present embodiment. The operating sequence identification table defines a correspondence relationship (pattern) between two patterns; pattern 1 and pattern 2 , as candidates for pairs of a cyclic shift amount of each cyclic shift sequence and a Walsh sequence used for a first stream.
In pattern 1 , Walsh sequences “w 2 , w 2 , w 2 , w 2 , w 1 , w 1 , w 1 , w 1 ” are associated with cyclic shift amounts “0, 2, 3, 4, 6, 8, 9, 10.” On the other hand, in pattern 2 , Walsh sequences “w 1 , w 1 , w 1 , w 1 , w 2 , w 2 , w 2 , w 2 ” are associated with cyclic shift amounts “0, 2, 3, 4, 6, 8, 9, 10.”
Thus, when attention is focused, for example, on the cyclic shift sequence of cyclic shift amount 0 , the operating sequence identification table defines a pair of cyclic shift amount 0 and Walsh sequence w 1 and a pair of cyclic shift amount 0 and Walsh sequence w 2 according to pattern 1 or pattern 2 .
Pilot information determining section 110 determines transmission bands of pilot signals based on the resource assignment information inputted from scheduling section 109 , and selects the above-described correspondence relationship (pattern) that can reduce inter-sequence interference of these pilot signals.
Pilot information determining section 110 outputs information indicating the selected correspondence relationship (pattern) to coding section 101 and estimation section 108 . When the operating sequence identification table is configured of only one pattern, it is not necessary to report which pattern is selected or report the selected pattern, and it is therefore unnecessary to report information indicating the selected correspondence relationship (pattern).
Furthermore, pilot information determining section 110 determines a combination (pair) of a cyclic shift sequence and a Walsh sequence of the first stream from the selected correspondence relationship (pattern).
Pilot information determining section 110 determines Walsh sequences of pilot signals used in the second and subsequent streams in substantially the same way as in Embodiment 1. That is, pilot information determining section 110 determines correspondence relationships with Walsh sequences in the second and subsequent streams from among correspondence relationships between a stream number and a Walsh sequence (e.g., pattern A and pattern B shown in FIG. 8 ) based on the Walsh sequences of the first stream determined above. For example, pilot information determining section 110 determines pattern A when the Walsh sequence of the first stream is w 1 and determines pattern B when w 2 .
Furthermore, pilot information determining section 110 determines cyclic shift amounts of cyclic shift sequences in the second and subsequent streams in addition to the correspondence relationship. For example, pilot information determining section 110 determines cyclic shift amounts of cyclic shift sequences in the second and subsequent streams by adding a fixed offset to the cyclic shift amount of the first stream. Alternatively, assuming the cyclic shift amounts of cyclic shift sequences in the second and subsequent streams are reported as control information, pilot information determining section 110 may determine the cyclic shift amounts of cyclic shift sequences in the second and subsequent streams based on this control information. Pilot information determining section 110 then outputs information indicating the determined cyclic shift amounts and information indicating the correspondence relationship between a stream number and a Walsh sequence to estimation section 108 and outputs information indicating the cyclic shift amount to coding section 101 .
The base station then reports the cyclic shift amounts used for cyclic shift sequences in the first stream per scheduling.
Furthermore, the base station reports information indicating which correspondence relationship of pattern 1 or pattern 2 is used to the terminal at an interval longer than a scheduling interval. Examples of signaling reported at an interval longer than a scheduling interval include MAC header, RRC signaling or higher layer signaling such as broadcast information.
The configuration of the terminal according to Embodiment 2 of the present invention is similar to the configuration of Embodiment 1 shown in FIG. 9 and is different only in some functions, and therefore only different functions will be described using FIG. 9 .
Pilot information determining section 204 stores an operating sequence identification table storing a plurality of correspondence relationships (patterns) between a cyclic shift amount and a Walsh sequence. Pilot information determining section 204 then determines the correspondence relationship between a cyclic shift amount and a Walsh sequence, based on information indicating the correspondence relationship between a cyclic shift amount and a Walsh sequence inputted from decoding section 203 (information reported at an interval longer than that of scheduling).
For example, as the correspondence relationship between a cyclic shift amount and a Walsh sequence, the operating sequence identification table stores pattern 1 and pattern 2 as shown in FIG. 12 , and pilot information determining section 204 determines the correspondence relationship based on the information indicating the correspondence relationship between a cyclic shift amount and a Walsh sequence inputted from decoding section 203 (information on pattern 1 or pattern 2 ).
Furthermore, pilot information determining section 204 determines a Walsh sequence according to information on the cyclic shift amount inputted from decoding section 203 and the above-described correspondence relationship. The information determined here is outputted to pilot signal generation section 205 .
Pilot information determining section 204 determines pilot signals used in the second and subsequent streams in substantially the same way as in pilot information determining section 110 . For example, pilot information determining section 204 stores a plurality of correspondence relationships between a stream number and a Walsh sequence, and determines the correspondence relationships with Walsh sequences in the second and subsequent streams from among correspondence relationships between a stream number and a Walsh sequence (e.g., pattern A or pattern B shown in FIG. 8 ), based on the determined Walsh sequence (w 1 or w 2 ) of the first stream.
Furthermore, pilot information determining section 204 determines cyclic shift amounts of cyclic shift sequences in the second and subsequent streams according to information on the cyclic shift amount of the first stream inputted from decoding section 203 in the same way as in pilot information determining section 110 . The cyclic shift amounts of the cyclic shift sequences determined here are outputted to pilot signal generation section 205 .
Next, the correspondence relationship (pattern) between a cyclic shift amount and a Walsh sequence according to the present embodiment will be described in detail. In the present embodiment, pilot information determining section 204 stores an operating sequence identification table storing a plurality of correspondence relationships (patterns) between a cyclic shift amount and a Walsh sequence, and switches between the correspondence relationships (patterns) at an interval longer than the scheduling interval.
The present embodiment reports information indicating a correspondence relationship (pattern) between a cyclic shift amount and a Walsh sequence at an interval longer than the scheduling interval, and can thereby suppress increases in the amount of reporting. Furthermore, by associating a cyclic shift amount with a Walsh sequence, it is possible to change a Walsh sequence by selecting a cyclic shift amount, and thereby maintain the degree of freedom in changing a Walsh sequence per scheduling.
That is, the cyclic shift amount of a cyclic shift sequence is information reported per scheduling, and by associating the cyclic shift amount of a cyclic shift sequence with a Walsh sequence, it is possible to control the cyclic shift amount of a cyclic shift sequence reported per scheduling and set a Walsh sequence, and thereby change a Walsh sequence per scheduling.
Furthermore, by defining a plurality of correspondence relationships (patterns) between a cyclic shift amount and a Walsh sequence and selecting one of the plurality of correspondence relationships (patterns), the possibility that both w 1 and w 2 may be associated as Walsh sequences associated with their respective cyclic shift amounts increases and the flexibility of Walsh sequences assigned to each terminal can be increased. For example, in two types of patterns in FIG. 12 , w 1 and w 2 are associated with a cyclic shift sequence of a cyclic shift amount of 2, and therefore when the cyclic shift sequence of cyclic shift amount 2 is assigned to the terminal, selection is possible from two types of Walsh sequences w 1 and w 2 .
Furthermore, when eight types of cyclic shift amounts and two types of Walsh sequences are used to a maximum degree for the number of code-multiplexed sequences (four types at most), there are as many as 16 alternatives in selecting a sequence of pilot signals, and therefore even when the number of alternatives (degree of freedom) of pilot signals is reduced, influences of the pilot signals on inter-sequence interference are small. Therefore, even when the number of alternatives decreases (flexibility deteriorates) in the cyclic shift sequence and Walsh sequence, influences on the performance of the entire system are small.
A case has been described above where a plurality of correspondence relationships (patterns) between a cyclic shift amount and a Walsh sequence are provided and the correspondence relationships (patterns) are reported at a long interval, but the correspondence relationships (patterns) may be fixed to one type as shown in FIG. 13 . This results in reporting with only three bits of a cyclic shift amount as in the case of the prior art, and can thereby further reduce the amount of reporting on Walsh sequences. Furthermore, as described above, when eight types of cyclic shift amounts and two types of Walsh sequences are used to a maximum degree with respect to the number of code-multiplexed sequences (four types at most), there are as many as 16 alternatives in selecting a sequence of pilot signals, and therefore even when the number of alternatives (degree of freedom) of pilot signals is reduced, influences of the pilot signals on inter-sequence interference are small.
When only an LTE-A terminal is assumed, associating the same number of Walsh sequences w 1 and w 2 with cyclic shift sequences makes it possible to equalize the probabilities of w 1 and w 2 being used respectively and substantially equalize the probabilities of inter-sequence interference occurring between pilot signals. Of the pairs of a cyclic shift amount and a Walsh sequence, the patterns shown in FIG. 12 and FIG. 13 respectively are examples where the number of pairs with Walsh sequence w 1 and the number of pairs with Walsh sequence w 2 are equal. That is, in the respective patterns shown in FIG. 12 and FIG. 13 , four Walsh sequences w 1 and four Walsh sequences w 2 are associated with eight types of cyclic shift amounts. Here, when “0, 2, 3, 4, 6, 8, 9, 10” are defined as cyclic shift amounts as in LTE, a correspondence relationship between cyclic shift amounts “0, 2, 3, 4, 6, 8, 9, 10” and Walsh sequences may be defined. Furthermore, when other “1, 5, 7, 11” are defined as cyclic shift amounts, a correspondence relationship between all cyclic shift amounts “0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11” and Walsh sequences may be defined.
Furthermore, when cyclic shift amount Δ 0 (Δ 0 <12) used for the first stream is reported, cyclic shift amount Δ 1 used for the second stream is assumed to be (Δ 0 +6)mod12, and the cyclic shift amount is assumed to be a ½ symbol length so that the interval between cyclic shift amounts becomes largest (difference in cyclic shift amounts becomes a maximum) (that is, the interval between cyclic shift amounts is 6), with respect to the pair of the cyclic shift amounts, which are most distant from each other (e.g., cyclic shift amount (0, 6)), the Walsh sequence associated with one cyclic shift amount that forms the pair may be different from the Walsh sequence associated with the other cyclic shift amount.
FIG. 14 is an example of the operating sequence identification table in which of a pair of cyclic shift amounts, which are most distant from each other (e.g., cyclic shift amount (0, 6)), the Walsh sequence associated with the one cyclic shift amount that forms the pair is different from the Walsh sequence associated with the other cyclic shift amount. As shown in FIG. 14 , for example, Walsh sequence w 1 is associated with cyclic shift amount “0” and w 2 is associated with cyclic shift amount “6” which is most distant from the cyclic shift amount “6”. Similarly, Walsh sequence w 1 is associated with cyclic shift amounts “2, 3, 4” and w 2 is associated with cyclic shift amounts “8, 9, 10” which are most distant from cyclic shift amounts “2, 3, 4” respectively. Thus, as shown in FIG. 14 , different Walsh sequences w 1 and w 2 are associated with cyclic shift amounts making up pairs of cyclic shift amounts (0, 6), (2, 8), (3, 9), (4, 10), which are most distant from each other respectively.
As shown in the operating sequence identification table in FIG. 14 , advantages in the case where cyclic shift amount Δ 1 of the second stream is set to a cyclic shift amount (that is, Δ 1 =Δ 0 +6), which is most distant from cyclic shift amount Δ 0 of the first stream, will be described using FIG. 15 .
In FIG. 15 , candidates for pairs of a cyclic shift amount of each cyclic shift sequence and a Walsh sequence used for the first stream are defined in an operating sequence identification table. A case will then be considered where cyclic shift amount Δ 1 of the second stream is set to a cyclic shift amount (that is, Δ 1 =Δ 0 +6) most distant from cyclic shift amount Δ 0 of the first stream. At this time, when “0” is reported as cyclic shift amount Δ 0 of the first stream, cyclic shift amount Δ 1 of the second stream is set to “6” and Walsh sequences of the first and second streams are set to w 1 . On the other hand, when “6” is reported as cyclic shift amount Δ 0 of the first stream, cyclic shift amount Δ 1 of the second stream is set to “0” and Walsh sequences of the first and second streams are set to w 2 .
That is, both the pairs of cyclic shift amounts of the first and second streams are (0,6), but Walsh sequences set in the first and second streams can be switched depending on which of “0” or “6” the base station reports to the terminal as cyclic shift amount Δ 0 of the first stream.
Thus, when the cyclic shift amount of the second stream is set to a cyclic shift amount distant by a predetermined amount of offset from the cyclic shift amount of the first stream in the operating sequence identification table, different Walsh sequences are associated with the cyclic shift amounts (CS 1 and CS 2 ) distant from each other by the predetermined amount of offset. Thus, it is possible to set different Walsh sequences in the first and second streams depending on whether the cyclic shift amount reported from the base station to the terminal is CS 1 or CS 2 .
On the other hand, when the cyclic shift amount of the second stream is set to a cyclic shift amount most distant from the cyclic shift amount of the first stream, if the same Walsh sequence is associated with the cyclic shift amounts (CS 1 and CS 2 ), which are most distant from each other in the cyclic shift amount, the same Walsh sequence is set regardless of whether the cyclic shift amount reported from the base station to the terminal is CS 1 or CS 2 . For this reason, the degree of freedom in changing Walsh sequences is reduced compared to a case where different Walsh sequences are associated with the cyclic shift amounts (CS 1 and CS 2 ), which are most distant from each other. Furthermore, in order to switch between Walsh sequences associated with cyclic shift amounts (CS 1 and CS 2 ) which are most distant from each other, as described using FIG. 12 , it is necessary to report through higher layer signaling which pattern should be used, which requires an extra reporting bit.
MODIFICATION EXAMPLE 1
While LTE-A terminals use Walsh sequence w 1 or w 2 , LTE terminals are not assumed to use Walsh sequences and have no requirements regarding Walsh sequences, which is equivalent to always using Walsh sequence w 1 . Here, assuming an environment in which LTE terminals and LTE-A terminals coexist, while the probabilities of LTE-A terminals using Walsh sequence w 1 and w 2 are substantially the same, the probability of LTE terminals using Walsh sequence w 1 is higher. Therefore, when Walsh sequence w 1 is used, the probability of inter-sequence interference occurring in pilot signals is higher than when Walsh sequence w 2 is used.
Thus, among pairs of a cyclic shift sequence and a Walsh sequence in a correspondence relationship (pattern) stored in the operating sequence identification table, the number of pairs of Walsh sequence w 1 is made to be smaller than the number of pairs of Walsh sequence w 2 . Here, Walsh sequence w 1 is [1 1] and is a sequence, all elements of which are composed of “1”s.
FIG. 16 is a diagram illustrating candidates for pairs of a cyclic shift sequence and a Walsh sequence. As shown in FIG. 16 , for example, Walsh sequences “w 1 , w 1 , w 1 , w 2 , w 2 , w 2 , w 2 , w 2 ” are associated with cyclic shift amounts “0, 2, 3, 4, 6, 8, 9, 10” respectively, and suppose the number of pairs with Walsh sequence w 1 is three and the number of pairs with Walsh sequence w 2 is five so that the number of pairs with Walsh sequence w 1 is smaller than the number of pairs with Walsh sequence w 2 .
Thus, providing a difference between the number of pairs with Walsh sequence w 1 and the number of pairs with Walsh sequence w 2 causes Walsh sequence w 2 less prone to inter-sequence interference to be more likely to be selected than Walsh sequence w 1 used by LTE terminals, and can thereby reduce inter-sequence interference from LTE terminals.
For example, in an environment in which there are many LTE terminals, making it easier to use Walsh sequences of w 2 in pattern 2 can reduce inter-sequence interference in pilot signals, while in an environment in which the number of LTE terminals is at the same level as that of LTE-A terminals, inter-sequence interference in pilot signals can be reduced by using substantially the same number of Walsh sequences w 1 and w 2 in pattern 1 . This correspondence relationship is changed at an interval longer than that of scheduling.
MODIFICATION EXAMPLE 2
In a cyclic shift sequence, the smaller the distance in cyclic shift amounts between cyclic shift sequences, the greater is inter-sequence interference. Inter-sequence interference is large, for example, between a cyclic shift sequence having a cyclic shift amount of 2 and a cyclic shift sequence having a cyclic shift amount of 1 or 3. Therefore, the closer in cyclic shift amounts, the more preferable it is to reduce inter-sequence interference using different Walsh sequences.
Thus, when neighboring cyclic shift amounts are discontinuous, any one of the same Walsh sequence and a different Walsh sequence is associated and when neighboring cyclic shift amounts are continuous, Walsh sequences of different signs are associated.
FIG. 17 is a diagram illustrating candidates for pairs of a cyclic shift sequence and a Walsh sequence. As shown in FIG. 17 , Walsh sequences “w 2 , w 1 , w 2 , w 1 , w 2 , w 2 , w 1 , w 2 ” are associated with cyclic shift amounts “0, 2, 3, 4, 6, 8, 9, 10” respectively and different Walsh sequences among neighboring cyclic shift amounts are associated with continuous cyclic shift amounts “2, 3, 4” and “8, 9, 10.”
Thus, by making Walsh sequences that form pairs with neighboring cyclic shift amounts differ from each other, it is possible to reduce inter-sequence interference between cyclic shift sequences of neighboring cyclic shift amounts having maximum inter-sequence interference.
(Modification example 1) and (modification example 2) may be combined. For example, in FIG. 17 , the number of pairs with Walsh sequence w 1 is three and the number of pairs with Walsh sequence w 2 is five so that the number of pairs with Walsh sequence w 1 is smaller than the number of pairs with Walsh sequence w 2 .
MODIFICATION EXAMPLE 3
In a cyclic shift sequence, the smaller the distance in cyclic shift amounts between cyclic shift sequences, the greater is inter-sequence interference. Therefore, the smaller the distance in cyclic shift amounts between cyclic shift sequences, the more preferable it is to use different Walsh sequences.
Therefore, Walsh sequence w 2 is paired with cyclic shift sequences of odd-numbered cyclic shift amounts and Walsh sequence w 1 is paired with cyclic shift sequences of even-numbered cyclic shift amounts.
FIG. 18 and FIG. 19 are diagrams illustrating candidates for pairs of a cyclic shift sequence and a Walsh sequence. As shown in FIG. 19 , also when the number of operating streams is assumed to be four, different Walsh sequences can be set between neighboring cyclic shift amounts, and therefore inter-sequence interference can be reduced. For example, the first terminal may use cyclic shift amounts “0, 6” and the second terminal may use cyclic shift amounts “3, 9” to perform MU (Multi User)-MIMO, and can thereby set different Walsh sequences among neighboring cyclic shift amounts while keeping the maximum interval between cyclic shift amount, and thereby reduce inter-sequence interference.
Furthermore, in LTE-A uplink MIMO transmission, not only cyclic shift amounts reported in LTE but all cyclic shift amounts may be used. For example, when cyclic shift amounts of the second stream are determined with an offset from the first stream, if offset amount 3 and cyclic shift amount 2 of the first stream are reported, the cyclic shift amount of the second stream is determined to be 5, and cyclic shift amount 5 which is not defined in LTE is used. In this case, if the above-described correspondence relationship is used, different Walsh sequences between neighboring cyclic shift amounts are also used, and it is thereby possible to reduce inter-sequence interference between cyclic shift sequences whose cyclic shift amounts are close to each other.
In the second and subsequent streams, Walsh sequences may be set as in the case of Embodiment 1 or without being limited to this, Walsh sequences may also be set in the second and subsequent streams as in the case of the first stream. For example, the base station may report cyclic shift amounts in the second and subsequent streams so that codes of Walsh sequences may be derived from cyclic shift amounts as in the case of the above-described first stream. Even if Embodiment 2 is applied independently of Embodiment 1, it is possible to suppress increases in the amount of reporting Walsh sequences.
(Embodiment 3)
In Embodiment 2, the correspondence relationship between a cyclic shift amount and a Walsh sequence used for the first stream is defined in the operating sequence identification table. Then, a case has been described where Walsh sequences of the second stream are Walsh sequences having the same sign as that in the first stream, Walsh sequences in the third and subsequent streams are selected from among Walsh sequences having the same sign as or a sign different from that of Walsh sequences used in the first and second streams or Walsh sequences having a sign different from that of the Walsh sequences in the first and second streams. That is, a method of implicitly determining Walsh sequences in the second and subsequent streams from stream numbers has been described.
The present embodiment will describe a method of implicitly determining Walsh sequences in the first stream, and second and subsequent streams according to cyclic shift amounts using one operating sequence identification table indicating a correspondence relationship between a cyclic shift amount and a Walsh sequence. That is, the present embodiment implicitly determines Walsh sequences in the first to fourth streams according to cyclic shift amounts using an operating sequence identification table independent of the number of streams (rank).
In the present embodiment, the base station and terminal share offset information, which is a difference between a cyclic shift amount of the first stream and cyclic shift amounts in the second to fourth streams beforehand, and the base station and terminal determines a cyclic shift amount of each stream based on the offset information.
FIG. 20 is a diagram illustrating an example of offset information indicating a difference between the cyclic shift amount of the first stream and the cyclic shift amounts of the second to fourth streams. Based on the offset information shown in FIG. 20 , upon receiving a report from the base station on cyclic shift amount Δ 0 (Δ 0 <12) used for the first stream (stream # 0 ), the terminal assumes cyclic shift amount Δ 1 used for the second stream (stream # 1 ) to be (Δ 0 +6)mod12, cyclic shift amount Δ 2 used for the third stream (stream # 2 ) to be(Δ 0 +3)mod12, and cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) to be (Δ 0 +9)mod12 (pattern 1 in FIG. 20 ). Alternatively, the terminal assumes cyclic shift amount Δ 2 used for the third stream (stream # 2 ) to be (Δ 0 +9)mod12, and cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) to be (Δ 0 +3)mod12 (pattern 2 in FIG. 20 ).
Since the configuration of the base station according to Embodiment 3 of the present invention is similar to the configuration of Embodiment 1 shown in FIG. 7 and is different only in some functions, only different functions will be described using FIG. 7 .
Pilot information determining section 110 determines cyclic shift amounts in cyclic shift sequences used for the second to fourth streams. Here, the cyclic shift amounts in the second and subsequent streams are determined by adding a fixed offset to the cyclic shift amount of the first stream. For example, when the base station and terminal share the offset information shown in pattern 1 in FIG. 20 , if the cyclic shift amount used for the first stream (stream # 0 ) from the base station is assumed to be Δ 0 (Δ 0 <12), pilot information determining section 110 determines cyclic shift amount Δ 1 used for the second stream (stream # 1 ) to be (Δ 0 +6)mod12, determines cyclic shift amount Δ 2 used for the third stream (stream # 2 ) to be (Δ 0 +3)mod12 and determines cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) to be (Δ 0 +9)mod2.
Furthermore, pilot information determining section 110 stores an operating sequence identification table storing a plurality of candidates for pairs of a cyclic shift amount and a Walsh sequence.
FIG. 21 is a diagram illustrating an example of the operating sequence identification table according to the present embodiment. The operating sequence identification table defines candidates for pairs of a cyclic shift amount of each cyclic shift sequence and a Walsh sequence used for the first stream. To be more specific, Walsh sequences “w 1 , (w 1 ), w 2 , w 2 , w 1 , (w 2 ), w 1 , (w 1 ), w 2 , w 2 , w 1 , (w 2 )” are associated with cyclic shift amounts “0, (1), 2, 3, 4, (5), 6, (7), 8, 9, 10, (11).”
Pilot information determining section 110 then sets Walsh sequences corresponding to the reported cyclic shift amounts of the first stream in Walsh sequences of the first stream based on the operating sequence identification table. Furthermore, Walsh sequences corresponding to cyclic shift amounts Δ 1 , Δ 2 and Δ 3 of the second, third and fourth streams are determined respectively.
Pilot information determining section 110 then outputs information on the cyclic shift amounts and Walsh sequences of each stream to coding section 101 and estimation section 108 . Since cyclic shift amounts in the second and subsequent streams are determined based on the cyclic shift amounts and offset information of the first stream, only cyclic shift amounts of the first stream may be inputted to coding section 101 . Furthermore, since Walsh sequences of each stream are determined from cyclic shift amounts of each stream, the Walsh sequences of each stream need not be inputted to coding section 101 .
The configuration of the terminal according to Embodiment 3 of the present invention is similar to the configuration of Embodiment 1 shown in FIG. 9 and is different only in some functions, and therefore only different functions will be described using FIG. 9 .
Pilot information determining section 204 determines cyclic shift amounts in the second and subsequent streams based on information on cyclic shift amounts of the first stream inputted from decoding section 203 and offset information shared beforehand between the base station and terminal. That is, the cyclic shift amounts in the second and subsequent streams are determined by adding a fixed offset to the cyclic shift amounts of the first stream reported as control information. For example, when the offset information shown in pattern 1 of FIG. 20 is shared between the base station and terminal, if the cyclic shift amount used for the first stream (stream # 0 ) from the base station is Δ 0 (Δ 0 <12), pilot information determining section 204 determines cyclic shift amount Δ 1 used for the second stream (stream # 1 ) to be (Δ 0 +6)mod12, determines cyclic shift amount Δ 2 used for the third stream (stream # 2 ) to be (Δ 0 +3)mod12 and determines cyclic shift amount Δ 3 used for the fourth stream (stream # 3 ) to be (Δ 0 +9)mod12.
Furthermore, pilot information determining section 204 determines Walsh sequences of each stream, based on the operating sequence identification table storing a correspondence relationship between a cyclic shift amount and a Walsh sequence shared between the base station and terminal. That is, pilot information determining section 204 selects Walsh sequences of each stream corresponding to determined cyclic shift amounts Δ 0 , Δ 1 , Δ 2 and Δ 3 of each stream from the operating sequence identification table. Pilot information determining section 204 then outputs the determined cyclic shift amounts and Walsh sequences of each stream to pilot signal generation section 205 .
Next, the operating sequence identification table according to the present embodiment shown in FIG. 21 will be described.
First, when an offset amount, which is a difference between the cyclic shift amount of the first stream and the cyclic shift amount of the second stream is assumed to be ΔCS, a pair of cyclic shift amounts, an interval of which is this offset amount ΔCS, will be considered. For example, when offset amount ΔCS is six, there are pairs of (0, 6), (2, 8), (3, 9) and (4, 10). As shown in FIG. 21 , in the present embodiment, cyclic shift amounts that form a pair are associated with the same Walsh sequence.
Thus, when a cyclic shift amount distant by offset amount ΔCS from a cyclic shift amount of the first stream is set as a cyclic shift amount of the second stream, cyclic shift amounts, an interval of which is ΔCS, are associated with the same Walsh sequence, and the first stream and second stream can thereby be set in the same Walsh sequence.
Furthermore, in the present embodiment, when groups (three types) are formed of cyclic shift sequences, an interval between cyclic shift amounts of which is 3 (that is, ½ of maximum value “6” of the cyclic shift amount interval), the respective groups are associated with only Walsh sequence w 1 , only Walsh sequence w 2 and both Walsh sequences w 1 and w 2 , respectively. For example, in the operating sequence identification table shown in FIG. 21 , the group formed of cyclic shift amounts “1, 4, 7, 10” is associated with only Walsh sequence w 1 . Furthermore, the group formed of cyclic shift amounts “2, 5, 8, 11” is associated with only Walsh sequence w 2 . Furthermore, the group formed of cyclic shift amounts “0, 3, 6, 9” is associated with two Walsh sequences w 1 and w 2 respectively.
FIG. 22 is a diagram illustrating a correspondence relationship between a cyclic shift amount and a Walsh sequence set in the second to fourth streams when the operating sequence identification table shown in FIG. 21 is used. As is clear from FIG. 22 , when the base station reports any one of cyclic shift amounts “0, 3, 6, 9” to the terminal, the first to fourth streams are associated with both Walsh sequences w 1 and w 2 . On the other hand, when the base station reports any one of cyclic shift amounts “1, 4, 7, 10” to the terminal, the first to fourth streams are associated with only Walsh sequence w 1 . Furthermore, when the base station reports any one of cyclic shift amounts “2, 5, 8, 11” to the terminal, the first to fourth streams are associated with only Walsh sequence w 2 . In LTE, “1, 5, 7, 11” cannot be reported as cyclic shift amounts, but by reporting cyclic shift amounts other than “1, 5, 7, 11,” the base station can set Walsh sequences of the first to fourth streams.
Thus, in the present embodiment, pilot information determining section 110 and pilot information determining section 204 store a single operating sequence identification table that defines candidates for pairs of a cyclic shift amount of each cyclic shift sequence and a Walsh sequence used for the first stream, and can thereby switch between Walsh sequences in the second and subsequent streams according to cyclic shift amounts of the first stream.
Furthermore, as is clear from FIG. 22 , when transmission is performed with two streams, the same Walsh sequence is set in the first stream and second stream irrespective of cyclic shift amounts. In the case of three or more streams, it is observed that by selecting cyclic shift amounts of the first stream to be reported, it is possible to select whether Walsh sequences used in the third and subsequent streams have the same sign as or a different sign from that of Walsh sequences used in the first and second stream. Pilot information determining section 110 and pilot information determining section 204 need only to store one operating sequence identification table indicating a “correspondence relationship between a cyclic shift amount and a Walsh sequence” as shown in FIG. 21 .
As described above, in the present embodiment, when offset amount ΔCS, which is a difference in cyclic shift amounts between the first stream and the second stream, is assumed to be fixed, in the operating sequence identification table, of a pair of cyclic shift amounts, which are distant by offset amount ΔCS from each other, the same Walsh sequence is associated with one cyclic shift amount and the other cyclic shift amount that form the pair. Thus, the same Walsh sequence is set in the first stream and the second stream irrespective of cyclic shift amounts.
When offset amount ΔCS, which is a difference in cyclic shift amounts between the first stream and the second stream, is a maximum value between the cyclic shift amounts, if cyclic shift amount groups, a cyclic shift amount interval of which is ½ of offset amount ΔCS are formed, the respective cyclic shift amount groups are associated with only a first Walsh sequence, only a second Walsh sequence and both the first and second Walsh sequences respectively. Thus, in the operating sequence identification table, in a plurality of cyclic shift amount groups formed of cyclic shift amounts, a cyclic shift amount interval of which is ½ of a maximum value of the cyclic shift amount interval, the Walsh sequence associated with cyclic shift amounts included in the first cyclic shift amount group is a first Walsh sequence, the Walsh sequence associated with cyclic shift amounts included in the second cyclic shift amount group is a second Walsh sequence and the Walsh sequences associated with cyclic shift amounts included in the third cyclic shift amount group are the first and second Walsh sequences. Thus, by selecting a cyclic shift amount of the first stream to be reported, it is possible to select whether the Walsh sequence used in the third and subsequent streams should be a Walsh sequence having the same sign as that of the Walsh sequence used in the first and second streams or a Walsh sequence having a different sign.
Thus, the present embodiment sets Walsh sequences in each stream using one “correspondence relationship between a cyclic shift amount and a Walsh sequence” and the amount of offset in cyclic shift amounts between the first stream and another stream. This eliminates the need for storing an operating sequence identification table for every stream number (rank) and also eliminates the need for processing corresponding to the plurality of operating sequence identification tables, and can thereby reduce the circuit scale. That is, by arranging cyclic shift amounts in the second and subsequent streams between the base station and terminal, cyclic shift amounts in the second and subsequent streams are determined by only reporting cyclic shift amounts of the first stream and Walsh sequences in each stream can be set using one “correspondence relationship between a cyclic shift amount and a Walsh sequence,” which is independent of the stream number (rank), with respect to this cyclic shift amount.
A case has been described above where the number of operating streams is four and pilot signals are transmitted using four streams as an example, but even in a case where the number of operating streams is 2 or 3, the Walsh sequence of the second stream is assumed to have the same sign as that of the Walsh sequence of the first stream and Walsh sequences in the third and subsequent streams are assumed to have the same sign or a different sign. Furthermore, when the number of streams of pilot signals is two or less, for example, when the number of transmission antennas is two or less, pilot signals are transmitted with the same Walsh sequence.
Furthermore, the pattern in which a cyclic shift sequence is associated with a Walsh sequence may differ from one cell to another. Even in the same cyclic shift sequence, Walsh sequences may be common or different between cells and inter-sequence interference of pilot signals can be randomized (averaged) between cells.
Furthermore, the above-described pattern numbers may be associated with UE-specific information (UEID or the like), cell ID or the like. This eliminates the need for reporting correspondence relationship patterns, and can reduce the amount of reporting from the base station.
Furthermore, the operating sequence identification table with the above-described patterns may be updated to a new operating sequence identification table by the base station reporting a new operating sequence identification table through higher layer signaling. That is, the table need not be specified by a specification. This allows a correspondence relationship pattern to be changed according to proportions of LTE terminals and LTE-A terminals.
A case has been described above where Walsh sequences are used in addition to cyclic shift sequences, but the present invention is not limited to Walsh sequences; the present invention is likewise applicable to any orthogonal sequence or sequence having a high level of orthogonality. For example, Walsh sequences may be substituted by OCC (Orthogonal Cover Code).
Furthermore, the Walsh sequence length is not limited to 2, but may be other sequence lengths.
Furthermore, assignment control information may also be referred to as “DCI (Downlink Control Information)” or “PDCCH.”
Furthermore, in Embodiment 1, the base station reports a correspondence relationship (pattern) between a stream number and a Walsh sequence to each terminal, but the base station may also report a Walsh sequence to be used for the first stream to each terminal.
Although an antenna has been described in the aforementioned embodiments, the present invention may be similarly applied to an antenna port.
The antenna port refers to a logical antenna including a single or a plurality of physical antenna(s). That is, the antenna port is not limited to a single physical antenna, but may refer to an array antenna including a plurality of antennas.
For example, in 3 GPP LTE, how many physical antennas are included in the antenna port is not specified, but the minimum unit allowing the base station to transmit different reference signals is specified.
In addition, the antenna port may be specified as a minimum unit for multiplying a weight of the pre-coding vector.
Also, although cases have been described with the above embodiment as examples where the present invention is configured by hardware, the present invention can also be realized by software.
Each function block employed in the description of each of the aforementioned embodiments may typically be implemented as an LSI constituted by an integrated circuit. These may be individual chips or partially or totally contained on a single chip. “LSI” is adopted here but this may also be referred to as “IC,” “system LSI,” “super LSI,” or “ultra LSI” depending on differing extents of integration.
Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After LSI manufacture, utilization of a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and settings of circuit cells within an LSI can be reconfigured is also possible.
Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Application of biotechnology is also possible.
The disclosure of Japanese Patent Application No. 2009-229649, filed on Oct. 1, 2009 and Japanese Patent Application No. 2010-086141, filed on Apr. 2, 2010, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
Industrial Applicability
The terminal station apparatus or the like according to the present invention is suitable for use as a terminal station apparatus or the like that reduces inter-sequence interference in pilot signals between terminals while suppressing to a low level inter-sequence interference in a plurality of pilot signals used by the same terminal even when SU-MIMO and MU-MIMO are applied simultaneously.
Reference Codes List
100 Base station
101 , 207 Coding section
102 , 208 Modulation section
103 , 212 RF transmission section
104 , 201 RF reception section
105 Separation section
106 , 111 DFT section
107 , 112 Demapping section
108 Estimation section
109 Scheduling section
110 , 204 Pilot information determining section
113 Signal separation section
114 IFFT section
115 , 202 Demodulation section
116 , 203 Decoding section
117 Error detection section
200 Terminal
205 Pilot signal generation section
206 CRC section
209 Allocation section
210 Multiplexing section
211 Transmission power/weight control section
|
A terminal apparatus is disclosed wherein even in a case of applying SU-MIMO and MU-MIMO at the same time, the inter-sequence interference in a plurality of pilot signals used by the same terminal can be suppressed to a low value, while the inter-sequence interference in pilot signal between terminals can be reduced. In this terminal apparatus ( 200 ): a pilot information deciding unit ( 204 ) decides, based on allocation control information, Walsh sequences of the respective ones of first and second stream groups at least one of which includes a plurality of streams; and a pilot signal generating unit ( 205 ) forms a transport signal by using the decided Walsh sequences to spread the streams included in the first and second stream groups. During this, Walsh sequences orthogonal to each other are established in the first and second stream groups, and users are allocated on a stream group-by-stream group basis.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a tip used for construction or demolition equipment which is adapted to be attached to a support and used in conjunction with, for example, a heavy-duty metal cutting shear, a plate shear, a concrete crusher, a grapple or other construction or demolition equipment. More particularly, the present invention relates to a replaceable tip secured to a support.
[0003] 2. Description of Related Art
[0004] For purposes of discussion herein, demolition and construction equipment may also be referred to as scrap handling equipment. The description of demolition equipment and construction equipment herein is not intended to be restrictive of the equipment being referenced. Demolition equipment, such as heavy-duty metal cutting shears, grapples and concrete crushers are mounted on backhoes powered by hydraulic cylinders for a variety of jobs in the demolition field. This equipment provides for the efficient cutting and handling of scrap. For example, in the dismantling of an industrial building, metal scrap, in the form of various diameter pipes, structural I-beams, channels, angles, sheet metal plates and the like must be efficiently severed and handled by heavy duty metal shears. Such shears can also be utilized for reducing automobiles, truck frames, railroad cars and the like. The shears must be able to move and cut the metal scrap pieces regardless of the size or shape of the individual scrap pieces and without any significant damage to the shears. In the demolition of an industrial building, concrete crushing devices, such as a concrete pulverizer or concrete crackers, are also used to reduce the structure to manageable components which can be easily handled and removed from the site. Wood shears and plate shears also represent specialized cutting devices useful in particular demolition or debris removal situations depending on the type of scrap. Also, a grapple is often utilized where handling of debris or work pieces is a primary function of the equipment. Historically, all of these pieces of equipment represent distinct tools having significant independent capital cost. Consequently, the demolition industry has tended to develop one type of tool that can be used for as many of these applications as possible.
[0005] For illustrative purposes, the following discussion will be directed to metal shears. One type of metal shear is a shear having a fixed blade and a movable blade pivoted thereto. The movable blade is pivoted by a hydraulic cylinder to provide a shearing action between the blades for severing the work pieces. Examples of this type of shears can be found in prior U.S. Pat. Nos. 4,403,431; 4,670,983; 4,897,921; 5,926,958; and 5,940,971 which are assigned to the assignee of this application and which are herein incorporated in their entirety by reference.
[0006] FIG. 1 illustrates a prior art, multiple tool attachment adapted to be attached to demolition or construction equipment, such as a backhoe (not shown). The multiple tool attachment is adapted to connect one of a series of tools or tool units to the demolition equipment. The tool attached in FIG. 1 is a metal shear 10 . The shear 10 includes a first blade 12 connected to an upper jaw 13 and a second blade 14 connected to a lower jaw 15 , wherein the jaws 13 , 15 are pivotally connected at a hub or main pin 16 to a universal body 18 . The body 18 is referred to as universal because it remains common to a series of tools or tool units in the attachment system. The universal body 18 is comprised of sides 19 , a bearing housing 20 and a yoke 21 .
[0007] The upper jaw 13 and the lower jaw 15 pivot about the main pin 16 to form a movable jaw assembly 22 . At the end of the first blade 12 is a blade tip 24 . Details of the blade tip 24 are provided in FIGS. 3 and 4 wherein the blade tip 24 is comprised of a base 26 having a top side 28 , bottom side 30 and walls 32 , 34 therebetween. The base 26 of the blade tip 24 is a completely solid piece and the top side 28 of the base 26 is secured to a support 36 associated with the upper jaw 13 .
[0008] Directing attention to FIGS. 1 and 2 the second blade 14 has associated with it a guide channel 38 which accepts and provides lateral support to the blade tip 24 and the first blade 12 . To minimize the deflection experienced under load by the first blade 12 and the blade tip 24 , the tolerance for the guide channel 38 is fairly low.
[0009] In many applications, the first blade 12 and support 36 may be laterally displaced relative to the guide channel 38 such that upon entering the guide channel 38 the side of the blade tip 24 experiences rubbing and extensive wear during normal operation. This wear if not properly maintained can lead to the first blade 12 becoming jammed or stuck in the guide channel 38 . This condition is known as “stickers” in the industry. Stickers can develop when the clearance gap between the walls 32 , 34 of the tip 24 of the first blade 12 and the walls 40 , 42 of the guide channel 38 of the lower blade 14 become excessive enough to allow material to become wedged between these surfaces while shearing. Once the first blade 12 becomes stuck within the guide channel 38 , the shear 10 must oftentimes be decommissioned for repair. It is then necessary to build up the walls 32 , 34 of the tip 24 by welding to keep these gaps at a minimum. This process is very time consuming and costly and, depending on the material that the shear is processing, building up the tip could be required as often as once a week.
[0010] Therefore, a tip design is desired that may be easily repaired or replaced when worn to minimize the downtime of a shear or other equipment.
SUMMARY OF THE INVENTION
[0011] On embodiment of the subject invention is directed to a tip for demolition and construction equipment having a discrete base with a top side, a bottom side and walls therebetween. The base also has a mounting surface on the top side of the base adapted to be secured to a support. The base furthermore has a central portion with a cutting edge, whereby the cutting edge is defined at the lowermost portion of the bottom side of the base. A recess extends into at least one wall of the base and the recess defines a recess upper side, an inner wall and a recess contour. An insert has a top side, a bottom side and walls therebetween with a cutting edge defined at the lowermost portion of the bottom side of the insert and generally aligned with the cutting edge of the base. The insert has a profile which generally conforms to the recess contour. An insert is secured within each recess.
[0012] Another embodiment of the subject invention is directed to the inserts which are secured within each base recess.
[0013] Yet another embodiment of the subject invention is directed to demolition and construction equipment utilizing such a tip.
[0014] Yet another embodiment of the subject invention is directed to a method of securing inserts within a tip for demolition and construction equipment comprising the steps of providing a common bore through the insert and the walls of the base at each recess, positioning an insert within each recess, inserting a fastener therethrough; and securing the fastener against each insert within the recess.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is prior art and is a side view illustrating a metal shear incorporated into a universal body for a construction tool system;
[0016] FIG. 2 is prior art and is a plan view of the shear in FIG. 1 ;
[0017] FIG. 3 is prior art and is a front view of a blade tip;
[0018] FIG. 4 is prior art and is a side view of the blade tip shown in FIG. 3 ;
[0019] FIG. 5 is an enlarged portion of the encircled section in FIG. 1 , however, with the introduction of a blade tip in accordance with the subject invention;
[0020] FIG. 6 is an exploded perspective view of the tip illustrated in FIG. 5 ;
[0021] FIG. 7 is an exploded section view of the blade tip wherein one insert has a recess to accept a nut;
[0022] FIG. 8 is a side view of the base associated with the blade tip;
[0023] FIG. 9 is a profile of the insert associated with the blade tip;
[0024] FIG. 10 is a side view of one insert having an internally threaded bore to accept a bolt; and
[0025] FIG. 11 is a perspective view of an alternate embodiment of an insert which is indexable in accordance with the subject invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.
[0027] FIG. 5 illustrates a blade tip 100 secured to a support 105 such as the upper jaw 13 of a jaw assembly 22 used in an industrial shear. It should be appreciated that although this tip 100 will be discussed in the context of an industrial shear associated with demolition equipment, it should be appreciated that such a blade tip 100 can be implemented on any type of equipment that shears, cuts, cracks, crunches or processes any type of material by motion of the blade tip.
[0028] The blade tip 100 may be utilized, for example, as a shear tip, claw tooth, crusher tooth and any and all piercing/punching devices that currently exist or that may be developed. This tip has immediate applications for products such as shears, claws, grapples, crushers, crackers, rail breakers, multi-blade cutters, tree shears, ripper teeth, grinding teeth, shearing teeth and any mechanism that can utilize a disposable cutting part which is subjected to wear.
[0029] Directing attention to FIGS. 6-9 , the tip 100 is comprised of a discrete base 114 having a top side 116 , a bottom side 118 and walls 120 , 122 therebetween. The base 114 has a mounting surface 124 on the top side 116 wherein the mounting surface 124 is adapted to be secured to the support 105 ( FIG. 5 ). The base 114 has a central portion 126 with a cutting edge 128 whereby the cutting edge 128 is defined at the lowermost portion 130 of the bottom side 118 of the base 114 . A recess 132 extends into at least one wall 120 , 122 of the base 114 . The recess 132 defines a recess upper side 134 , a recess inner wall 136 and a recess contour 138 ( FIG. 8 ). A second insert 184 will be described and is secured within a second recess 182 .
[0030] Directing attention to insert 150 , the insert 150 has a top side 152 , a bottom side 154 and walls 156 , 158 therebetween. A cutting edge 160 is defined at the lowermost portion 162 of the bottom side 154 of the insert 150 and is generally aligned with the cutting edge 128 of the base 114 .
[0031] Directing attention to FIGS. 8 and 9 , the profile 164 of the insert 150 generally conforms to the contour 138 of the recess 132 . The recess contour 138 is triangular and the profile 164 of the tip 150 corresponds to this shape. The insert 150 is secured within the recess 132 . Directing attention to FIG. 7 , when the insert 150 is secured within the recess 132 , the cutting edge 160 of the insert 150 is in approximate alignment with the cutting edge 128 of the base 114 . This is also true for insert 184 within the recess 182 .
[0032] To provide additional support to the insert 150 within the recess 132 , the top side 152 of the insert 150 is positioned against the upper side 134 of the recess 132 .
[0033] Redirecting attention to FIGS. 6 and 7 , the base 114 further includes a socket 166 extending into the inner wall 136 of the recess 132 . The insert 150 further includes a projection 168 extending from the wall 158 wherein the projection 168 fits within the socket 166 to support the insert 150 within the recess 132 .
[0034] As illustrated in FIGS. 8 and 9 , the socket 166 and the projection 168 have matching shapes and are noncircular such that when the insert 150 is mounted within the recess 132 there is no relative rotation between the socket 166 and the projection 168 .
[0035] As illustrated in FIGS. 6 and 7 , a common bore 170 extends through the insert 150 , the base 114 and the insert 184 . A fastener 172 passes through the common bore 170 and secures the inserts 150 , 184 within their respective recesses 132 , 182 . The fastener 172 may be a threaded bolt having a bolt head 174 and a threaded shaft 176 . The bore 170 may include a counter bore 173 within the insert 150 to accept the bolt head 174 and, furthermore, the bore 170 within the base 114 may have threads (not shown) to accept the threaded shaft 176 .
[0036] While so far only a single recess 132 and a single insert 150 have been discussed in detail, a second recess 182 is associated with the opposite wall 122 of the base 114 and a second insert 184 is secured within the recess 182 in the same fashion as the insert 150 is secured within the recess 132 . When the fastener 172 has a bolt head 174 and a threaded shaft 176 , the bore 170 of the insert 178 may have a countersink 178 to accept the nut 186 to engage the threaded shaft 176 of the bolt 172 .
[0037] In the alternative, an insert 190 having all of the features of insert 184 with the exception of a countersunk portion of the bore to accept the nut 186 may itself have a threaded bore 185 to accept the threaded shaft 176 of the bolt 172 , thereby alleviating the need for the nut 186 and the corresponding countersunk portion within the insert 184 to accommodate the nut 186 .
[0038] FIG. 11 illustrates a perspective view of an insert 200 having a top side 216 , a bottom side 218 and an additional third side 220 with walls 222 , 224 therebetween. Extending from the wall 224 of the insert 200 is a projection 226 that is centered about a bore 228 extending therethrough such that the projection 226 and the contour of the first, second and third sides 216 , 218 , 220 are symmetric. As a result, with obvious modifications to the base 114 to accept the insert 200 , the insert 200 may be indexable such that multiple cutting edges 230 , 232 , 234 may be positioned at the lowermost portion 130 of the bottom side 118 of the base 114 and when one cutting edge becomes worn the insert 200 may be rotated such that a second cutting edge is exposed.
[0039] The invention is also directed to a method of securing an insert 150 within a tip 100 for demolition and construction equipment comprising the step of providing a common bore 170 through the insert 150 and the walls 136 , 137 of the base 114 at each recess 132 , 176 . Each insert 150 , 178 is positioned within its respective recess 132 , 176 . A fastener 172 is inserted within the common bore 170 and the fastener 172 is then secured against each insert 150 , 178 within their respective recess 132 , 176 .
[0040] It should be appreciated that under most circumstances the only maintenance for the tip 100 will be the replacement of the inserts 150 , 184 . However, it is possible to remove the base 114 from the support 36 to replace the entire tip 100 such that the tip 100 may be considered to be disposable. Furthermore, depending upon the application for which the tip 100 may be used, the material of the base 114 and the material of the tip 100 may be different.
[0041] As a result of the tip 100 in accordance with the subject invention, machine down time and the associated expense may be significantly reduced because worn tips may be quickly and easily replaced.
[0042] This invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.
|
A tip for demolition and construction equipment has a discrete base with at least one recess therein to accept a replaceable insert. The insert has a projection that fits within a mating socket within the base. A threaded bolt may extend through a common bore within the insert and base to secure the insert to the base. The tip may also include a second opposing insert which is held within a respective recess by a common bolt.
| 4
|
FIELD OF THE INVENTION
[0001] The present invention relates to a transition metal cluster catalyst and usage thereof in various reactions.
PRIOR ART
[0002] Recently, palladium and platinum particles have been used in organic synthetic reactions. Since conventional reactions using metal nano-particles are homogenous systems and consequently separation of metals from products is difficult, metals remain in products to remarkably increase load in environment, which is a big problem. Furthermore, it is another problem that, even if metals are recovered, the metal catalyst becomes wastes eventually.
[0003] Therefore, it is required to develop such catalysts as those without having the above problems, i.e. catalysts effective without using organic solvents from a viewpoint of environment pollution and catalysts easily recoverable and reusable.
[0004] To resolve the above problems, it has been examined to subjecting an insoluble carrier to support metal particles. For example, the present inventors developed a polymeric resin catalyst containing palladium particles and performed oxidation of alcohols, reduction of alkenes and dechlorination reaction of allyl chloride (Reference 1).
[0005] Reference 1: WO2002/072644
Problems to be Solved by the Invention
[0006] The polymeric resin catalyst containing palladium and platinum particles developed by the present inventors (Reference 1, Japanese Patent Application No. 2005-064911, Japanese Patent Application No. 2005-064913 etc.) is an excellent catalyst functional in water, recoverable and reusable. However, since the polymeric resin using is a modified resin, the catalyst is expensive, and also the catalyst needs a resin-supporting ligand. Then, the objective of the present invention is to develop a simple and inexpensive catalyst using a chain polymer without need of using a resin and a ligand, which is effectively functional in the absence of organic solvents.
[0007] Namely, the objective of the present invention is to provide a catalyst, which has enough catalytic activity as a transition metal particle catalyst including platinum family and the like, is easily separable from products, is reusable and is easily prepared.
Means to Solve the Problems
[0008] To prepare the transition metal cluster catalyst of the present invention, an insoluble complex is prepared by forming a complex between a polymer with nitrogen-containing group, such as pyridinium and ammonium group in the principal chain, and a later transition metal compound; and then reducing the complex with a reductant. It is believed that during the above process, the complex becomes unstable and is destroyed, then the metal fine particles are incorporated into the polymer. In other words, a chain polymer becomes a matrix, and a transition metal forms clusters and is incorporated into the insoluble complex. In the product, the fine metal clusters bridge polymers and are in turn stabilized by the chain polymers. Therefore, a stable and reusable metal cluster catalyst is generated.
[0009] Therefore, the present invention is a transition metal cluster catalyst, wherein transition metal clusters are supported by a polymer, which is obtained by reduction reaction of a complex of a transition metal and a polymer, wherein the complex is represented by a general formula (1):
[0000] (—NR 1 R 2 —R 5 —NR 3 R 4 —R 6 —) m M 1 n
[0000] wherein R 1 , R 2 , R 3 and R 4 represent independently an aryl group or an alkyl group, and NR 1 R 2 and NR 3 R 4 may form a pyridine ring, an acridine ring or a quinoline ring that may have substituent(s); R 5 represents an arylene group, an alkylene group, or mixture of these groups that may have substituent(s); R 6 represents a covalent bond or an alkylene group; M 1 represents a transition metal salt; m represents a number corresponding to molecular weight of the polymer; and n represents a number satisfying that m/n is from 1 to 10.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a photograph of the field emission scanning electron microscope of the catalyst.
[0011] FIG. 2 shows a photograph of the field emission scanning electron microscope of the catalyst.
[0012] FIG. 3 shows the EDS (electron dispersion x-ray analysis) spectrum of the catalyst observed by the field emission scanning electron microscope.
EFFECT OF THE PRESENT INVENTION
[0013] Organic solvents have been used for organic synthesis because of its prominent solubilizing agent for an organic compound. However, recently the use is severely restricted because of its effect as an environmental pollutant. Consequently, a reaction in the absence of an organic solvent or in the presence of water as a solvent is interfered because of hard solubility or insolubility of a common organic compound. However, the catalyst of the present invention is capable of effectively catalyzing various reactions in the presence of water as a solvent. Furthermore, conventional transition metal catalyst needs to be used in the absence of oxygen or in the presence of inert gas, whereas the catalyst of the present invention has the advantage in that it can be used in the atmosphere.
[0014] The transition metal cluster catalyst of the present invention is an extremely useful catalyst for oxidation, reduction, cross-coupling, Heck reaction and alkylation reaction. Particularly, since alkylation process using the transition metal cluster catalyst of the present invention needs not to use highly toxic alkyl halide as a nucleophilic reagent and may use a primary alcohol, the process is capable of realizing reaction system without generating halogens and is an excellent “green chemistry”-oriented process.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The transition metal cluster catalyst of the present invention is obtained by reduction reaction of a complex comprising a transition metal salt and a polymer, wherein the complex is represented by the general formula (1):
[0000] C1: (—NR 1 R 2 —R 5 —NR 3 R 4 —R 6 —) m M 1 n
[0000] wherein R 1 , R 2 , R 3 and R 4 represent independently an aryl group or an alkyl group, and NR 1 R 2 and NR 3 R 4 may form a pyridine ring, an acridine ring or a quinoline ring, and preferably a pyridine ring, which may have substituent(s). The aryl group is preferably phenyl group and the carbon number of alkyl group is preferably equal to or less than 20. The substituent is preferably an aryl group or an alkyl group, and the aryl group is preferably phenyl group. The carbon number of alkyl group is preferably equal to or less than 4.
[0016] R 5 represents an arylene group, an alkylene group, or mixture of these groups, which may have substituent(s). The alkylene group has preferably carbon number between 1 and 20, is more preferably linear, and is even more preferably an alkylene group represented by —(CH 2 ) n —, wherein the carbon number (n) is preferably equal to or less than 10 and more preferably between 1 and 6. The arylene group is preferably a phenylene group or a naphthylene group. The substituent is preferably an aryl group or an alkyl group, the aryl group is preferably a phenyl group, and the alkyl group has preferably carbon number equal to or less than 4.
[0017] R 6 represents a covalent bond or an alkylene group. The alkylene group has preferably carbon number between 1 and 20, is preferably linear, and is more preferably an alkylene group represented by —(CH 2 ) n —, wherein the carbon number (n) is preferably equal to or less than 10 and more preferably between 4 and 6.
[0018] M 1 represents a transition metal salt and is represented by MX t . M is a transition metal, preferably a later transition metal (iron group and platinum group), more preferably palladium, nickel, platinum, cobalt, rhodium or iridium, even more preferably palladium or platinum.
[0019] X includes a halogen atom, carboxylate group (—OCOR 7 , wherein R 7 is not restricted, but is preferably a hydrocarbon group, more preferably an alkyl group or an aryl group), a carbonate group (CO 3− ), a phosphate group (PO 4 3− ), a sulphate group (SO 4 2− ), and a nitrate group (NO 3− ). t is an integer leading MX t to divalent anion.
[0020] m represents a number corresponding to molecular weight of the polymer. The molecular weight of the polymer depends on synthetic conditions, but is generally between about 5,000 and 1,000,000. n represents a number satisfying the ratio m/n is between 1 and 10. The ratio m/n is preferably selected so that the charge number of the quaternary ammonium is stoichiometrically balanced with that of the transition metal salt.
[0021] The preferable example of the complex includes a compound represented by the general formula (2):
[0000]
[0000] wherein k is a number corresponding to R 5 , l is a number corresponding to R 6 , and m, n, M, X and t are as defined above, and the pyridine ring may contain substituent(s), or represented by the general formula (3):
[0000]
[0000] wherein k and l represent the number corresponding to R 5 , j is a number corresponding to R 6 , and m, n, M, X and t are as defined above, and the pyridine ring and the benzene ring may contain substituent(s).
[0022] The complex can be obtained, for example, by a reaction between a tertiary amine compound and a halogen compound to synthesize a polymer containing quaternary ammonium, and then by a reaction between the polymer and a transition metal salt.
[0023] The tertiary amine is represented by the following formula (4):
[0000] NR 1 R 2 —R 5 —NR 3 R 4 ,
[0000] wherein R 1 , R 2 , R 3 , R 4 , R 5 are as defined above.
[0024] The halogen compound is represented by the following formula (5):
[0000] X 1 —R 6 —X 2 ,
[0000] wherein X 1 and X 2 represent independently a halogen atom, preferably a chlorine atom or a bromide atom, and R 6 is as defined above.
[0025] These tertiary amine compounds are reacted with the halogen compound. A highly polar solvent is preferably used as a solvent and includes acetonitril, acetone, dimethylformamide, dimethylacetamide, t-butyl alcohol and the like.
[0026] The concentration of the reactants is between about 0.01 and 1 M, and preferably about 0.25 M.
[0027] The atmosphere of the reaction is any of air, nitrogen and argon.
[0028] The reaction temperature is selected between 0° C. and the reflux temperature of the solvent, and is preferably about 82° C. The reaction time is between about 1 and 144 hr, and preferably about 24 hr.
[0029] As a result of the reaction, a polymer containing a quaternary ammonium represented by the following formula (6) is obtained:
[0000] (—NR 1 R 2 —R 5 —NR 3 R 4 —R 6 ) m ,
[0000] wherein R1, R2, R3, R4, R5 are as defined above and the molecular weight is generally between about 5,000 and 1,000,000 under general reaction conditions.
[0030] Then the polymer is reacted with the above transition metal salt.
[0031] A highly polar solvent is preferably used as a solvent and includes water, methanol, ethanol, propanol, 2-propanol, t-butanol, chloroform and the like. Especially, water is preferably used.
[0032] The concentrations of the reactants are between about 0.001 and 0.1 M, and preferably about 0.01 M.
[0033] The atmosphere of the reaction is any of air, nitrogen and argon.
[0034] The reaction temperature is selected between −78° C. and 100° C., and is preferably around at room temperature. The reaction time is between about 1 sec and 7 days, and preferably about 1 hr.
[0035] After the reaction, the complex of formula (1) comprising the transition metal and the polymer is obtained as an insoluble product. The present complex is insoluble to water and the above organic solvent, and is able to recover and reuse. The recovery method includes filtration, centrifugation, recovery of the supernatant, and the like.
[0036] Then the complex is subjected to reduction reaction.
[0037] The reductant used to the reduction reaction includes a metal hydride reagent, a metal or ammonium salt of formic acid, a primary or secondary alcohol, and hydrogen, and a metal hydride reagent is preferably used among them.
[0038] A metal hydride reagent includes an alkali metal, alkali earth metal, or an ammonium salt of aluminum metal family (boron, aluminum and the like) hydride, and includes specifically NaBH 4 , LiBH 4 , LiAlH 4 and the like.
[0039] A metal or ammonium salt of formic acid includes preferably an alkali metal, alkali earth metal, or an ammonium salt of formic acid, and precisely formic acid and a metal or ammonium salt thereof such as formic acid, ammonium formate and sodium formate. A primary or secondary alcohol includes methanol, ethanol, propanol, 2-propanol, butanol, benzilalcohol, and the like.
[0040] The reduction reaction can be performed in the presence or absence of a solvent. For the reaction in the presence of a solvent, the solvent includes water, alcohols such as methanol, ethanol, 2-propanol, butanol, benzilalcohol, and preferably ethanol, tetrahydrofrane, methyltetrahydrofrane, tetrahydropyrane, and ethers such as diethylether, diisopropylether. The reaction mixture is added with a reductant at the temperature less than the melting temperature of a solvent, wherein the temperature is between 0 and 100° C. for water, between −78° C. and 150° C. for alcohols, and preferably 25° C.; is stirred for period between 0.1 sec and 72 hr, preferably about 6 hr, at the temperature between −78° C. and 150° C., preferably at 25° C.; and generates the desired cluster catalyst.
[0041] The transition metal cluster catalyst is stabilized in a state, wherein transition metal clusters with diameter between about 1 and 5 nm are supported by the polymers.
[0042] The catalyst of the present invention is effectively functional in oxidation reaction, reduction reaction, homo-coupling reaction, cross-coupling reaction, Heck reaction, alkylation reaction or the like, and particularly for α-alkylation reaction.
[0043] In the α-Alkylation reaction, any kinds of ketones containing α-hydrogen can be used as a substrate, and any kinds of primary alcohols can be used as a reagent.
[0044] An alkylated product at α-site of substrate ketone is produced by the reaction using alkali, alkali earth metal base, amines as a base, at the temperature between −78° C. and 200° C., in the absence of a solvent, in the presence of a highly polar solvent such as water, alcohol, dimethylformamide and the like or in the presence of a nonpolar solvent such as toluene, ether, hydrocarbon and the like.
[0045] The α-alkylation reaction is represented by the following reaction formula (7):
[0000] R 8 —CO—CH(R 9 )+HO—R 10 →R 1 —CO—C(R 9 ) 2 —R 10 ,
[0000] wherein R 8 , R 9 and R 10 are not restricted but each may represent hydrocarbon group, and R 9 is preferably a hydrogen atom.
[0046] In reduction reaction, for example, by allowing a compound with double bond or triple bond such as alkene or alkine to react with hydrogen, formic acid or salts thereof in the presence of alcohol at the temperature between −78° C. and 150° C., a corresponding alkane can be produced.
[0047] In oxidation reaction, for example, by allowing alcohols to react with an oxidant such as air, oxygen, hydrogen peroxide, t-butylhydroperoxide, dimethylsilylperoxide, or the like at the temperature between −78° C. and 150° C., a corresponding ketone, aldehyde or carboxylic acid can be produced.
[0048] In coupling reaction, for example, by allowing aryl halides, alkenyl halides or alkane halides to react in the presence of an organic metal reagent (organic boron, organic aluminum, organic zinc or organic zirconium) at the temperature between −78° C. and 200° C., a corresponding coupling compound can be produced.
[0049] In Heck reaction, for example, by allowing aryl halides, alkenyl halides or alkane halides to react with alkenes at the temperature between −78° C. and 200° C., a corresponding arylalkene, dialkene, or alkene can be produced.
[0050] The following Examples illustrate the present invention, but are not intended to limit the scope of the present invention.
Example 1
[0051] 4,4′-bipyridine (1.56 g; 10 mmol: Tokyo Chemical Industry, Co., Ltd.) and 1,4-bis(bromomethyl)toluene (2.64 g; 10 mmol: Aldrich) are dissolved in acetonitrile (50 mL) and water (50 mL) and the solution was stirred at 100° C. for 24 hr. After the reactant was cooled to a room temperature, it was subjected to an evaporator for removal of the solvent, was washed with chloroform (200 mL), acetone (200 mL) and chloroform (200 mL), was dried under reduced pressure. As the result, poly{(1,4-bipyridil)-co-[1,4-bis(bromomethyl)benzene]}(the following compound 1) was obtained (4.0 g, yield>99%). The analytical result is shown as follows:
[0052] CP-MAS 13 C NMR (232 MHz; solid) 148.1, 145.2, 135.1, 133.1, 127.3, 60.8; calcd. for C 18 H 16 Br 2 N 2 .2H 2 O: C, 47.39%; H, 4.42%; N, 6.14%. found: C, 47.98%; H, 4.24%; N, 6.27%.
[0053] The obtained aqueous solution (100 mL) dissolving palladium chloride (Furuya Metal Co., Ltd.)(4 mmol) and sodium chloride (80 mmol) was mixed with the aqueous solution (100 mL) of the obtained poly{(1,4-bipyridil)-co-[1,4-bis(bromomethyl)benzene]}(4 mmol; 1.68 g) at 25° C. The mixture generated precipitation. After the mixture was stirred for further 1 hr, the precipitation was filtrated, washed with water, and dried. As the result, an insoluble product was obtained (the following compound 2)(1.77 g; yield 87%). The analytical result is shown as follows:
[0054] CP-MAS 13 C NMR (232 MHz; solid) δ 148.9, 146.8, 135.0, 131, 1, 128.0, 64.4; IR (ATR) v 3471, 3117, 3055, 2920, 2851, 1636, 1611, 1436, 1421, 809, 768 cm −1 ; Anal. calcd. for C 18 H 16 Br 2 Cl 2 N 2 Pd.3H 2 O: C, 33.18%; H, 3.40%; N, 4.30%. found: C, 31.91%; H, 2.66%; N, 4.33%.
[0055] The obtained insoluble product (1.77 mmol; 900 mg) was dispersed in ethanol (75 mL), was slowly mixed with sodium boron hydride (Wako Pure Chemical Industry Lyd., 11.9 mmol) dispersed in ethanol (75 mL) at 25° C., and the mixture was changed to a black dispersion solution. The solution was stirred for further 6 hr, and the precipitates were filtrated, washed with water and dried. As the result, an insoluble product (the following formula, the catalyst of compound 3)(630 g; yield 81%) was obtained. The analytical result is shown as follows:
[0056] CP-MAS 13 C NMR (232 MHz; solid) δ 130.9, 128.8, 63.9, 56.8, 52.8, 42.1, 31.5, 15.5; IR (ATR) v 3471, 3117, 3054, 2920, 2851, 1636, 1436, 1236, 1090, 891 cm −1 ; Anal. calcd. for C 18 H 16 Br 2 N 2 Pd.3H 2 O: C, 37.24%; H, 3.82%; N, 4.82%. found: C, 37.51%; H, 3.72%; N, 5.08%.
[0057] The reaction of the present Example is shown by the following reaction formula (8):
[0000]
[0058] The obtained catalyst was examined by a field emission scanning electron microscope (JEOL Ltd., JSM-6700, Voltage 5 kV, Magnification ×2300). The photograph is shown in FIG. 1 . FIG. 1 shows a micrometer-scale configuration of the catalyst and exemplifies porosity with size of about 1 μm.
[0059] Measurement by field emission transmission electron microscopy (JEOL Ltd., JEM-2100F, Voltage 200 kV, Magnification ×250000) was performed. The photograph is shown in FIG. 2 . FIG. 2 shows that the black colored region is palladium, and a polymer is present at the border. It was observed that palladium clusters were dispersed on aggregated polymers.
[0060] Energy dispersive X-ray analysis (EDS) was performed by field emission scanning electron microscopy (JSM-6700). The result is shown in FIG. 3 . FIG. 3 exemplified that palladium clusters were generated, bromide anions were present on the polymer as anions, and a small amount of chlorides were contained.
[0061] The Pd clusters generated in the present Example have diameter of about 2 nm according to the observation by field emission transmission electron microscopy, have neutral charge according to the reaction mechanism of generating zero valent neutral clusters by reduction of divalent palladium, and are carried by the polymer.
Example 2
[0062] The catalyst obtained in Example 1 (10 mg), barium hydroxide monohydrate (63 mg), water (42 μL), 2-octanone (0.334 mmol), and 1-octanol (0.668 mmol) were stirred at 100° C. for 24 hr under air atmosphere, were added with ethyl acetate after cooling, and were centrifuged (4000 rpm, 5 min) to provide supernatant. The supernatant was concentrated, was purified by a column chromatography, and provided 7-hexadecanone at the yield of 83%. The catalyst recovered by the centrifugation was washed with water, was dried for 12 hr under 5 Pascal, and was reused for the same reaction to provide 7-hexadecanone at the yield of 90%. Further the same procedure provided 7-hexadecanone at the yield of 91%.
[0063] 1 H NMR (CDCl 3 ) 2.38 (t., J=7.6 Hz, 4H), 1.54-1.59 (m, 4H), 1.26-1.31 (m, 18H), 0.88 (t, J=6.7 Hz)
[0064] The reaction of the present Example is shown by the following reaction formula (9)
[0000]
Example 3
[0065] The catalyst obtained in Example 1 (10 mg), barium hydroxide monohydrate (63 mg), water (42 μL), 2-octanone (0.334 mmol), and 1-decanol (0.668 mmol) were stirred at 100° C. for 24 hr under air atmosphere, were added with ethyl acetate after cooling, and were centrifuged (4000 rpm, 5 min) to provide supernatant. The supernatant was concentrated, was purified by a column chromatography, and provided 7-octadecanone at the yield of 84%.
[0066] 1 H NMR (CDCl 3 ) 2.31 (t, J=8 Hz, 4H), 1.47-1.51 (m, 4H), 1.15-1.31 (m, 12H), 0.81 (t, J=7 Hz, 6H)
[0067] The reaction of the present Example is shown by the following reaction formula (10)
[0000]
Example 4
[0068] The catalyst obtained in Example 1 (10 mg), barium hydroxide monohydrate (63 mg), water (42 μL), 2-octanone (0.334 mmol), and benzyl alcohol (0.668 mmol) were stirred at 100° C. for 24 hr under air atmosphere, were added with ethyl acetate after cooling, and were centrifuged (4000 rpm, 5 min) to provide supernatant. The supernatant was concentrated, was purified by a column chromatography, and provided 1-phenyl-3-nonanone at the yield of 91%.
[0069] 1 H NMR (CDCl 3 ) 7.25-7.28 (m, 2H), 7.17-7.19 (m, 3H), 2.89 (t, J=7.3 Hz, 2H), 2.72 (t, J=7.3 Hz, 2H), 2.37 (t, J=7.3 Hz, 2H), −1.52-1.56 (m, 2H), 1.24-1.30 (m, 6H), 0.87 (t, 6.7 Hz, 3H)
[0070] The reaction of the present Example is shown by the following reaction formula (11):
[0000]
|
The present invention provides a catalyst, which has enough catalytic activity as a transition metal particle catalyst including platinum family and the like, is easily separable from products, is reusable and is easily prepared. To prepare the transition metal cluster catalyst of the present invention, an insoluble complex is prepared by forming a complex between a polymer with nitrogen-containing group, such as pyridinium and ammonium group in the principal chain, and a later transition metal compound; and then reducing the complex with a reductant. The transition metal forms clusters, which are stabilized by the polymers. Namely, the present invention is a transition metal cluster catalyst, wherein transition metal clusters are supported by a polymer, which is obtained by reduction reaction of a complex of a transition metal and a polymer with nitrogen-containing group. The transition metal cluster catalyst of the present invention is an extremely useful catalyst for oxidation, reduction, cross-coupling, Heck reaction, alkylation reaction and the like.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the benefits of priority of U.S. Provisional Patent Application No. 61/601,086, entitled “Support Frame for an Implement” and filed at the United States Patent and Trademark Office on Feb. 21, 2012; the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to frames and frame assemblies for supporting implements on vehicles and more particularly relates to frames and frame assemblies for supporting implements on small vehicles such as, but not limited to, all-terrain vehicles (“ATV” or “ATVs”) and utility-terrain vehicle (“UTV” or “UTVs”).
BACKGROUND OF THE INVENTION
[0003] All-terrain vehicles (“ATV” or “ATVs”), utility-terrain vehicle (“UTV” or “UTVs”), and other similar vehicles, are often equipped with implements such as plows to allow the vehicles to displace snow, dirt, soil, gravel, etc. Such implements are typically removably mounted to the vehicles via appropriate supporting frames or supporting frame assemblies.
[0004] Though several different configurations of supporting frames have been proposed and devised throughout the years, most supporting frames can be categorized either as front-mounted (i.e. mounted to the front of the vehicle) or as underside-mounted (i.e. mounted to the underside of the vehicle).
[0005] A front-mounted supporting frame is generally configured to be mounted near or at the front end of the vehicle. Hence, due to its frontal position, the front-mounted supporting frame typically allows the implement to be easily raised when not in use.
[0006] However, due to its frontal position, the front-mounted supporting frame is typically less effective at distributing the load that the implement transfers to the vehicle when in use. This is generally caused by the relatively large operating angle of the supporting frame with respect to the frame of the vehicle when the implement is in use.
[0007] The underside-mounted supporting frame mitigates some of the shortcomings of front-mounted supporting frames, and more particularly the load distribution problem mentioned above. Indeed, as the underside-mounted frame is mounted underneath the vehicle, typically between the front and rear wheels, the supporting frame defines a smaller operating angle with respect to the frame of the vehicle, and the load generated by the implement is thereby more evenly transferred to the frame of the vehicle.
[0008] However, despite the foregoing advantage, an underside-mounted supporting frame typically has less ground clearance than a front-mounted supporting frame since the frame cannot be raised as high as a front-mounted supporting frame. Indeed, in an underside-mounted supporting frame, the supporting frame ultimately abuts on the underside of the vehicle when it is raised by the winch.
[0009] There is therefore a need for an improved underside-mounted supporting frame which mitigates at least some of the aforementioned shortcomings.
SUMMARY OF THE INVENTION
[0010] At least some of the shortcomings of prior art support frames for implements are mitigated by a support frame which comprises a front section hingedly connected to a rear section and which is downwardly biased by a biasing assembly.
[0011] Hence, a support frame for an implement, in accordance with the principles of the present invention, generally extends longitudinally and generally comprises, at its rear end, a rear attachment mechanism for removably mounting the rear end of the support frame to the underside of the vehicle, and at its front end, an implement attachment assembly for supporting the implement.
[0012] The rear attachment mechanism typically allows the support frame to pivot with respect to the vehicle, thereby allowing the support frame to be raised and lowered as needed, typically by the winch of the vehicle. In typical though non-limitative embodiments of the support frame, the rear attachment mechanism is a latching mechanism that comprises one or more latches (e.g. two latches).
[0013] The support frame also comprises a rear section and a front section hingedly connected thereto. The hinge connection between the front and rear sections is configured to allow the front section to be pivotable between an operative position wherein the front section is substantially not pivoted with respect to the rear section, and an inoperative position wherein the front section is pivoted upwardly with respect to the rear section. Hence, the hinge connection between the front and rear sections generally allows only upward pivotal movements of the front section with respect to the rear section.
[0014] The support frame also comprises a biasing assembly or mechanism which downwardly biases the front section into the operative position.
[0015] Still, in accordance with the principles of the present invention, the downward bias of the biasing assembly can be overcome, typically by the winch of the vehicle, such as to allow the front section to pivot upwardly with respect to the rear section (i.e. in the inoperative position) in order to provide more clearance between the implement and the ground surface.
[0016] In typical though non-limitative embodiments of a support frame, the support frame is configured to support a plow.
[0017] Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:
[0019] FIG. 1 is a rear perspective view of a support frame in accordance with the principles of the present invention and equipped with a plow.
[0020] FIG. 2 is a side view of the support frame of FIG. 1 .
[0021] FIG. 3 is a front perspective view of the support frame of FIG. 1 , without the plow.
[0022] FIG. 4 is a fragmentary side view of the support frame of FIG. 1 .
[0023] FIG. 5 is a fragmentary side perspective view of the support frame of FIG. 1 .
[0024] FIG. 6 is another fragmentary side perspective view of the support frame of FIG. 1 .
[0025] FIG. 7 is a partial side view of the support frame of FIG. 1 .
[0026] FIG. 8 is another partial side view of the support frame of FIG. 1 .
[0027] FIG. 9 is a partial bottom perspective view of the support frame of FIG. 1 .
[0028] FIGS. 10A to 10C are sequential side views of the support frame of FIG. 1 , mounted to an ATV, during the raising of the support frame.
[0029] FIG. 11 is a front perspective view of another support frame in accordance with the principles of the present invention.
[0030] FIG. 12 is a fragmentary side perspective view of the support frame of FIG. 11 .
[0031] FIG. 13 is another fragmentary side perspective view of the support frame of FIG. 11 .
[0032] FIG. 14 is a partial bottom perspective view of the support frame of FIG. 11 .
[0033] FIG. 15 is a fragmentary partial bottom perspective view of the support frame of FIG. 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] A novel support frame for an implement will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.
[0035] Referring first to FIGS. 10A to 10C , an embodiment of a support frame 20 , in accordance with the principles of the present invention, is depicted mounted to a vehicle 10 . In FIGS. 10A to 10C , the vehicle 10 is an ATV. However, the vehicle 10 could be a UTV or any other similar small vehicles.
[0036] In the present embodiment, the support frame 20 is pivotally mounted to a mounting rod 16 located on the underside 14 of the frame 12 of the vehicle 10 . The mounting rod 16 can be either mounted to the underside 14 of the frame 12 or integral therewith. As it will be best understood below, this pivotal connection between the support frame 20 and the frame 12 allows the implement mounted to the support frame 20 to be lowered toward the ground in a working position (see FIG. 10A ), and raised from the ground in an non-working position (see FIGS. 10B and 10C ). In other embodiments, the support frame 20 could be mounted to the underside 14 of the vehicle 10 via different attachment mechanisms. However, these other attachment mechanisms must still allow the support frame 20 to pivot with respect to the frame 12 of the vehicle 10 .
[0037] Referring now to FIGS. 1 to 3 , the present embodiment of the support frame 20 is shown in greater details.
[0038] The support frame 20 generally has a front end 22 and a rear end 24 . The front end 22 is configured to support an implement. In the present embodiment, the implement is a plow 26 of typical configuration. In that sense, it is to be understood that the support frame 20 would typically be used to support a plow 26 . However, the support frame 20 is not limited to supporting a plow 26 and could therefore support other types of implements.
[0039] To properly secure the plow 26 to the front end 22 , the support frame 20 generally comprises an attachment plate 28 which is pivotally mounted to the support frame 20 , near or at the front end 22 . This attachment plate 28 comprises a base portion 30 , two lateral wing-shaped portions 32 and 34 extending laterally and upwardly from the base portion 30 , and a frontal portion 36 located at the forward extremity of the base portion 30 and of the lateral portions 32 and 34 .
[0040] As best shown in FIGS. 1 and 2 , the plow 26 is pivotally mounted to the frontal portion 36 such as to be pivotable along a substantially horizontal axis 37 (see FIG. 2 ). However, the frontal portion 36 comprises side stoppers 38 and 40 on which the two back ribs 42 and 44 of the plow 26 can respectively abut to limit the rearward pivotal movements of the plow 26 . To limit the forward pivotal movements of the plow 26 , a pair of springs 46 and 48 are respectively mounted between the back ribs 42 and 44 and the lateral portions 32 and 34 . The springs 46 and 48 generally allow the plow 26 to temporarily pivot forwardly when the plow 26 encounters an obstacle.
[0041] The attachment plate 28 is pivotally mounted to the support frame 20 such as to be pivotable along a substantially vertical axis 29 (see FIG. 1 ). The pivotal movements of the attachment plate 28 allow the angle of the plow 26 to be adjusted with respect to the general longitudinal direction of the support frame 20 . In the present embodiment, the angle of the plow 26 can be adjusted via the interaction of an actuatable spring-loaded locking lever 50 and a series of angularly disposed notches 52 formed at the rear extremity of the attachment plate 28 (see FIG. 1 ).
[0042] To adjust the angle of the plow 26 , the lever 50 is removed from its current notch 52 , the attachment plate 28 is pivoted until the desired angular notch 52 is aligned with the lever 50 , and then the lever 50 is inserted into the new notch 52 to lock the attachment plate 28 , and thus the plow 26 , in its new angular position.
[0043] Referring now to FIGS. 1 to 6 , the rear end 24 of the support frame 20 comprises a rear attachment mechanism 54 which is configured to pivotally engage the mounting rod (or rods) 16 located underneath the vehicle 10 (see FIGS. 10A to 10C ).
[0044] In the present embodiment, the rear attachment mechanism 54 is a latching mechanism and comprises two latches 56 and 58 mounted on each side of the support frame 20 near or at the rear end 24 . Latch 56 comprises a fixed side plate 60 and a hook-shaped member 62 pivotally mounted thereto. The member 62 is biased into a locked position, i.e. the position shown in the figures, by a biasing member such as a spring (not shown). Similarly, latch 58 comprises a fixed side plate 64 and a hook-shaped member 66 pivotally mounted thereto. The member 66 is also biased into a locked position, i.e. the position shown in the figures, by a biasing member such as a spring (not shown).
[0045] Understandably, as the latches 56 and 58 are pushed against the mounting rod 16 during the installation of the support frame 20 on the vehicle 10 , the mounting rod 16 will force the members 62 and 66 open. The biasing members will then force the members 62 and 66 in their locked position when the mounting rod 16 is fully inserted into the latches 56 and 58 (see FIGS. 10A to 10C ).
[0046] The members 62 and 66 can also be pivoted in an unlocked position by an unlocking actuating device 68 (e.g. a pedal that can be depressed by the user) operatively connected to the members 62 and 66 via a linkage assembly 70 and a laterally extending rod 72 fixedly connected to the members 62 and 66 .
[0047] As indicated above, the pivotal connection between the latches 56 and 58 and the mounting rod 16 allows the support frame 20 to be lowered and raised. This is typically done with the assistance of a winch 18 (and its cable 19 ) mounted at the front of the vehicle 10 (see FIGS. 10A to 10C ).
[0048] In other embodiments, the rear attachment mechanism could be different. Still, the rear attachment mechanism needs to allow the support frame 20 to pivot with respect to the frame 12 of the vehicle 10 in order for the support frame 20 to be lowered and raised.
[0049] In accordance with the principles of the present invention, the support frame 20 comprises a rear portion 74 and a front portion 76 pivotally mounted thereto. As it will be best understood below with reference to FIGS. 10A to 10C , the front portion 76 can pivot upwardly with respect to the rear portion 74 in order to provide greater ground clearance when the plow 26 is not in use.
[0050] In the present embodiment, the rear portion 74 and the front portion 76 are pivotally connected by a pair of hinges 78 and 80 which define a substantially horizontal rotation axis 79 (see FIG. 3 ). In other embodiments, the rear portion 74 and the front portion 76 could be pivotally connected by only one hinge or by more than two hinges.
[0051] Referring now to FIGS. 7 to 9 , from an operative position of the front portion 76 (see FIG. 7 ), the hinges 78 and 80 are configured to allow only upward pivotal movements of the front portion 76 with respect to the rear portion 74 , i.e. to an inoperative position (see FIG. 8 ). In that sense, the rotation axis 79 of the hinges 78 and 80 is located in the upper portion of the hinges 78 and 80 (see FIGS. 7 and 8 ).
[0052] The hinge 78 comprises complementary hinge members 82 and 84 which are respectively secured to the rear portion 74 and to the front portion 76 . In the present embodiment, the hinge member 84 is configured to abut on the rear portion 74 when the hinge 78 is closed and thus when the front portion 76 is in its operative position (see FIG. 7 ). Hence, hinge member 84 prevents the front portion 76 from pivoting downwardly with respect to the rear portion 74 . Hinge 80 similarly comprises complementary hinge members 86 and 88 which are respectively secured to the rear portion 74 and to the front portion 76 . Hinge 80 functions as hinge 78 .
[0053] Referring back to FIGS. 3 to 6 , to prevent the front portion 76 from freely pivoting upwardly with respect to the rear portion 74 , the support frame 20 comprises a biasing assembly 90 which normally biases the front portion 76 in its operative position, i.e. with the hinges 78 and 80 in closed position.
[0054] In the present embodiment, the biasing assembly 90 is mounted to the rear portion 74 and generally comprises a leaf spring 92 (i.e. a resilient member) which longitudinally extends between a rear supporting member or plate 94 , mounted to the rear portion 74 , and a front supporting member or plate 96 , mounted to the front portion 76 . Still, in the present embodiment, the extremities 91 and 93 of the leaf spring 92 are not secured to the rear supporting plate 94 and to the front supporting plate 96 . In fact, the extremities 91 and 93 of the leaf spring 92 respectively rest on the supporting plates 94 and 96 such that they are substantially free to slide on the supporting plates 94 and 96 when the front portion 76 is upwardly pivoted with respect to the rear portion 74 .
[0055] In the present embodiment, the leaf spring 92 is further pivotally mounted to a pair of supporting brackets 98 and 100 via a rod or shaft 102 which is pivotally mounted to the brackets 98 and 100 . As illustrated in FIG. 6 , in the present embodiment, the leaf spring 92 is secured to the shaft 102 with a fastener (e.g. a bolt and a nut). In other embodiments, the leaf spring 92 could be secured to the shaft 102 using other method such as, but not limited to, welding.
[0056] The brackets 98 and 100 are further secured (e.g. fastened, bolted, welded, etc.) to a middle or intermediate supporting member or plate 104 which is itself secured to the rear portion 74 of the support frame 20 . As shown in FIGS. 4 to 6 , the middle supporting plate 104 is longitudinally located between the rear supporting plate 94 and the front supporting plate 96 .
[0057] Understandably, in the present embodiment, the load supported by the leaf spring 92 when the front portion 76 is pivoted upwardly with respect to the rear portion 74 is at least partially transferred to the supporting brackets 98 and 100 , to the middle supporting plate 104 , and thus, to the rear portion 74 .
[0058] As best illustrated in FIGS. 4 and 5 , in the present embodiment, the brackets 98 and 100 also support, in their upper portion, a stopping member or plate (or stopper) 106 which is configured to abut on the underside 14 of the vehicle 10 when the support frame 20 is raised by the winch 18 (see also FIGS. 10B and 10C ). Still, in other embodiments, the stopping plate 106 could be mounted elsewhere on the rear portion 74 .
[0059] In other embodiments, the leaf spring 92 could be differently mounted to the rear portion 74 . For instance, in FIGS. 11 to 15 , the leaf spring 92 is pivotally mounted to a rod 110 , fixedly mounted to the rear portion 74 , via a mounting assembly 112 . The mounting assembly 112 comprises a top plate 114 and a bottom U-shaped bracket 116 fastened to each other (e.g. with bolts 118 and nuts 120 ).
[0060] Understandably, the biasing assembly 90 can have many different configurations.
[0061] Referring now to FIGS. 10A to 10C , the operation of the support frame 20 will be described in details.
[0062] As first shown in FIG. 10A , in use, the support frame 20 , in its operative position, is pivotally mounted to the frame 12 of the vehicle 10 , and more particularly to the mounting rod 16 located underneath the vehicle 10 , and the support frame 20 is lowered with the winch 18 such that the plow 26 engages the ground.
[0063] When the plow 26 is no longer needed, the support frame 20 is raised with the winch 18 in order to raise the plow 26 from the ground.
[0064] As the support frame 20 is raised, the stopping plate 106 ultimately ends up contacting the underside 14 of the vehicle 10 as best shown in FIG. 10B . Understandably, when the stopping plate 106 contacts the underside of the vehicle 10 , the rear portion 74 of the support frame 20 cannot be raised any more.
[0065] However, as best shown in FIG. 10C and in accordance with the principles of the present invention, since the front portion 76 of the support frame 20 is pivotally mounted to the rear portion 74 , the front portion 76 can be further raised as the winch 18 overcomes the downward bias of the biasing assembly 90 . Hence, as the winch 18 does overcome the downward bias of the biasing assembly 90 , the front portion 76 pivots upwardly with respect to the rear portion 74 which is blocked by the underside 14 of the vehicle 10 . This additional upward pivotal movement of the front portion 76 raises the plow 26 further upward, thereby increasing the ground clearance of the plow 26 with respect to the ground (see FIG. 10C ).
[0066] Understandably, as the plow 26 is needed again, the winch 18 will lower the support frame 20 first from its inoperative position (see FIG. 10C ) to its operative position (see FIG. 10B ), during which the downward bias of the biasing assembly 90 will close the hinges 78 and 80 , and then toward the ground (see FIG. 10A ).
[0067] By having a second pivoting point located between the rear end 24 and the front end 22 , and by allowing the front portion 76 to pivot upwardly with respect to the rear portion 74 , the support frame 20 in accordance with the principles of the present invention generally mitigates the problem of ground clearance of underside-mounted implement supporting frames.
[0068] Still, it will be understood that the location of the second pivoting point along the support frame 20 will be chosen such to take into account the configuration of the vehicle 10 and more particularly the position underneath the vehicle 10 where the rear end 24 of the support frame 20 will be mounted with respect to the front extremity of the vehicle 10 .
[0069] While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
|
A frame for supporting an implement (e.g. a plow) on a vehicle is disclosed. The support frame extends longitudinally and generally comprises, at its rear end, a rear attachment mechanism for removably mounting the support frame to the underside of the vehicle, and at its front end, a front attachment assembly for supporting the implement. The frame comprises a rear section and a front section hingedly connected together such that the front section can pivot upwardly with respect to the rear section. The support frame also comprises a biasing assembly or mechanism, generally comprising a resilient member engaging the front and rear sections, such as to downwardly bias the front portion. By overcoming the downward bias of the biasing assembly, the front section can be further raised with respect to the ground surface, thereby providing greater clearance.
| 4
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a semiconductor module such as a memory module. A “semiconductor module” herein refers to a module having one or more parts including a semiconductor package mounted on one substrate.
[0003] 2. Description of the Background Art
[0004] Information equipment such as a personal computer has a memory module mounted as a semiconductor module. A common and conventional memory module will now be described. First, in FIG. 9, a semiconductor package 1 mounted on a memory module is shown. Semiconductor package 1 includes a package body 2 and a plurality of leads 3 protruding in parallel, respectively from opposing side portions. A dimension of semiconductor package 1 is determined by an organization for standardizing a semiconductor package, JEDEC (Joint Electron Device Engineering Council), and a “TSOP” (Thin Small Out-line Package) of “400 mil” is one example. When semiconductor package 1 is an SDRAM (Synchronous Dynamic Random Access Memory), 54 pins are provided, pitch A between leads 3 is set to 0.8 mm, and width B per one lead 3 is set to 0.3 mm.
[0005] As shown in FIG. 10, a memory module 100 has semiconductor package 1 mounted on a surface of substrate 4 in a prescribed arrangement. On the surface of substrate 4 , in addition to semiconductor package 1 , a packaged parts 5 a , 5 b such as a resistance, and a buffer IC (Integrated Circuit) 6 for amplifying and timing a signal of the memory are also mounted. In order to make effective use of a limited area on substrate 4 , packages are often mounted on opposing surfaces of substrate 4 , as shown in FIG. 11. On both surfaces of substrate 4 , pads 7 are formed in positions corresponding respectively to leads 3 , which are electrically connected to pads 7 respectively. In an example shown in FIGS. 10 and 11, nine semiconductor packages 1 are mounted on one surface of substrate 4 of 133.35 mm long and 31.75 mm wide, which is a dimension determined in accordance with JEDEC standard. This means that, in total, eighteen semiconductor packages 1 are mounted on both surfaces.
[0006] As personal computers and the like are more sophisticated, an increase of memory capacity has been demanded. Accordingly, more semiconductor packages need to be mounted per one substrate. In an effort to achieve this, in Japanese Patent Laying-Open No. 4-276649, a technique to stack and mount a semiconductor package is proposed. According to the technique, as shown in FIG. 12, a semiconductor package 1 e having a longer lead is prepared in addition to semiconductor package 1 . As shown in FIGS. 13 and 14, a two-layered structure is provided on one surface of substrate 4 . That is, an inner pad 7 having a conventional arrangement and a pad 7 e arranged outside the former together form pads on the surface of substrate 4 . In the two-layered structure of the semiconductor packages, lead 3 of semiconductor package 1 located on a side close to substrate 4 (hereinafter, referred to as a “lower layer”) is connected to pad 7 , while a lead 3 e of semiconductor package 1 e overlying the former on a side far from substrate 4 (hereinafter, referred to as an “upper layer”) relative to semiconductor package 1 is connected to pad 7 e , going around the outside of lead 3 . In this case, however, a row of pad 7 e for upper layer semiconductor package le should be arranged parallel to, and outside, a row of pad 7 for lower layer semiconductor package 1 . Therefore, width of the area occupied on substrate 4 will be larger. Consequently, for example, though nine semiconductor packages could conventionally be arranged per one layer on one surface of substrate 4 , only eight semiconductor packages per one layer on one surface can be arranged, as can be seen in a memory module 101 shown in FIG. 15.
[0007] Further improved techniques are possible as described below. As shown in FIG. 16, a semiconductor package if is prepared, which is a 400 mil package having 54 pins in accordance with a conventional standard. Though pitch between leads 3 f is the same as a conventional example, width C per one lead 3 f is made smaller to 0.16 mm. This semiconductor package 1 f is provided as a lower layer. Separately, a semiconductor package 1 g is prepared having a lead 3 g that has the same length as lead 3 f when viewed from the top and has longer length than the same when viewed from the side. This package is provided as an upper layer. Width C per one lead 3 g of semiconductor package 1 g is also made smaller to 0.16 mm. Both packages are mounted, with one overlying the other, as shown in FIGS. 17 and 18. The pad of upper layer semiconductor package 1 g and the pad of lower layer semiconductor package 1 f are alternately arranged, and lead 3 g of semiconductor package 1 g is interposed between leads 3 f of semiconductor package 1 f respectively. Consequently, as can be seen in a memory module 102 shown in FIG. 19, nine packages can be arranged per one layer on one surface of substrate 4 , as in a conventional example.
[0008] In FIG. 20, an enlarged view of the vicinity of a root portion of the lead is shown. Generally, a plurality of leads protruding in parallel from a side portion of a package body of the semiconductor package are manufactured in the following manner. A package body 2 portion is formed with resin mold so as to partially cover a leadframe 14 integrally formed. Thereafter, as shown in FIG. 21, a punch region 13 set on a dambar 12 linking each lead in a portion protruding from the side portion of package body 2 is punched through, and thus each lead is separated. In an attempt to punch the region to completely remove dambar 12 linking each lead, a puncher may strike a lead portion and damage the lead, or useful life of the puncher may be shortened. Therefore, usually, punch region 13 is set to a size covering only a main portion of dambar 12 with a small clearance from the lead portion, not exactly covering both full ends of dambar 12 . Accordingly, as shown in FIG. 22, after punching, a dambar residual portion 8 will remain in the middle of lead 3 . Lead 3 is folded thereafter, to have a shape shown in FIG. 23. In FIG. 23, the semiconductor package is shown, disposed on substrate 4 . Here, the lead can be divided in three parts: a lead drawn-out portion 31 horizontally drawn from the side portion of package body 2 ; a lead extending-downward portion 32 hereinafter, referred to as a “lead downward portion”) extending down to the surface of substrate 4 ; and a lead foot portion 33 for contacting pad electrode 7 .
[0009] A side view of the techniques described with reference to FIGS. 16 to 19 is shown in FIG. 24. Width of the lead is made smaller in both upper and lower layers so that lead 3 g of upper layer semiconductor package 1 g passes a gap between leads 3 f of lower layer semiconductor package 1 f . In practice, however, as dambar residual portion 8 is present, the gap where lead 3 g can pass is narrow. Therefore, only a slight displacement of a position of either the upper or lower semiconductor package may cause a contact of lead 3 f with lead 3 g.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide a semiconductor module capable of increasing the mountable number of semiconductor packages per one layer on one surface of a substrate as well as avoiding contacts between leads due to a dambar residual portion.
[0011] In order to achieve the object above, a semiconductor module according to the present invention includes a substrate having a pad electrode on a surface, a lower layer semiconductor package mounted on the substrate, and an upper layer semiconductor package mounted on the substrate while arranged in a position substantially overlying the lower layer semiconductor package. The lower layer semiconductor package and the upper layer semiconductor package include a package body and a plurality of leads protruding in parallel respectively from opposing side portions of the package body and electrically connected to the pad electrode. The pad electrode having the lead of the upper layer semiconductor package connected and the pad electrode having the lead of the lower layer semiconductor package connected are alternately arranged. The lead includes a lead drawn-out portion horizontally drawn from a side portion of the package body, a lead downward portion extending from the lead drawn-out portion down to a surface of the substrate and a lead foot portion continuing to a tip end of the lead downward portion and contacting the pad electrode. The lead has a dambar residual portion protruding toward the lead adjacently protruding from the same package body in any position the middle between the lead drawn-out portion and the lead downward portion. An inner surface of the lead downward portion of the upper layer semiconductor package is positioned outside an outer surface of the lead downward portion of the lower layer semiconductor package. By adopting this structure, even if slight displacement of the relative positions of upper and lower layer semiconductor packages, with one overlying the other, may occur, contact of the lead of the upper layer semiconductor package with the dambar residual portion of the lower layer semiconductor package can be prevented.
[0012] In the present invention, preferably, when viewed two-dimensionally, the pad electrode is arranged in a staggered manner so that the pad electrode connected to the upper layer semiconductor package is located outside and the pad electrode connected to the lower layer semiconductor package is located inside, with a projection region onto the substrate of the package body serving as a center. By adopting this structure, while minimizing a material for the pad electrode, a connection portion to the lead can efficiently be arranged in a limited area.
[0013] In the present invention, preferably, a horizontal distance from the package body to the dambar residual portion in the upper layer semiconductor package is substantially equal to a horizontal distance from the package body to the dambar residual portion in the lower layer semiconductor package, and the lead downward portions of the upper layer semiconductor package and the lower layer semiconductor package extend diagonally relative to the substrate. By adopting this structure, contact between the lead downward portions can be prevented, even if the lead drawn-out portions are of the same length.
[0014] In the present invention, preferably, the lead has a section including the dambar residual portion, wider than other sections. By adopting this structure, a conventional punching apparatus can be used, obviating the need of a new punching apparatus.
[0015] The present invention preferably includes a structure in which a plurality of combinations of the upper layer semiconductor package and the lower layer semiconductor package are vertically stacked. By adopting this structure, larger number of semiconductor packages can be mounted in unit area of the substrate, and a semiconductor module of high density and high performance can be obtained.
[0016] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a plan view of a semiconductor package mounted on a semiconductor module in a first embodiment according to the present invention.
[0018] [0018]FIG. 2 is a side view of the semiconductor module in the first embodiment according to the present invention.
[0019] [0019]FIG. 3 is a partially enlarged plan view of the semiconductor module in the first embodiment according to the present invention.
[0020] [0020]FIG. 4 is a plan view of the semiconductor module in the first embodiment according to the present invention.
[0021] [0021]FIG. 5 is a partially enlarged side view of the semiconductor module in the first embodiment according to the present invention.
[0022] [0022]FIG. 6 is a partially enlarged side view of a semiconductor module in a second embodiment according to the present invention.
[0023] [0023]FIG. 7 shows a manufacturing process of a semiconductor package used in the semiconductor module in the second embodiment according to the present invention.
[0024] [0024]FIG. 8 is a side view of a semiconductor module in a third embodiment according to the present invention.
[0025] [0025]FIG. 9 is a plan view of a common and conventional semiconductor package.
[0026] [0026]FIG. 10 is a plan view of a first semiconductor module according to a conventional art.
[0027] [0027]FIG. 11 is a side view of the first semiconductor module according to the conventional art.
[0028] [0028]FIG. 12 is a plan view of a semiconductor package used in a second semiconductor module according to the conventional art.
[0029] [0029]FIG. 13 is a side view of the second semiconductor module according to the conventional art.
[0030] [0030]FIG. 14 is a partially enlarged plan view of the second semiconductor module according to the conventional art.
[0031] [0031]FIG. 15 is a plan view of the second semiconductor module according to the conventional art.
[0032] [0032]FIG. 16 is a plan view of a semiconductor package used in a third semiconductor module according to the conventional art.
[0033] [0033]FIG. 17 is a side view of the third semiconductor module according to the conventional art.
[0034] [0034]FIG. 18 is a partially enlarged plan view of the third semiconductor module according to the conventional art.
[0035] [0035]FIG. 19 is a plan view of the third semiconductor module according to the conventional art.
[0036] [0036]FIG. 20 is a first illustration representing a manufacturing process of a common and conventional semiconductor package.
[0037] [0037]FIG. 21 is a second illustration representing the manufacturing process of the common and conventional semiconductor package.
[0038] [0038]FIG. 22 is a third illustration representing the manufacturing process of the common and conventional semiconductor package.
[0039] [0039]FIG. 23 is a partially enlarged side view from a first direction, of the common and conventional semiconductor package.
[0040] [0040]FIG. 24 is a partially enlarged side view from a second direction, of the common and conventional semiconductor package.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] (First Embodiment)
[0042] Referring to FIGS. 1 to 4 , a structure of a semiconductor module in a first embodiment according to the present invention will be described. In the semiconductor module, a semiconductor package 1 f shown in FIG. 16 is provided as a lower layer while a semiconductor package 1 h shown in FIG. 1 is provided as an upper layer. Semiconductor package 1 h has a lead 3 h , of which width C is 0.16 mm. When viewed from the top, the lead of semiconductor package 1 h appears to be slightly longer than that of semiconductor package 1 f . Both of the above packages are mounted on a substrate 4 , as shown in FIGS. 2 and 3. When viewed in a direction of FIG. 2, lead 3 h appears to run outside lead 3 f . Note that a dambar residual portion is not illustrated in FIG. 2.
[0043] As shown in FIG. 3, semiconductor package if and semiconductor package 1 h are stacked with a displacement by 0.4 mm, which is half the lead pitch A=0.8 mm. A pad 7 f for semiconductor package If and a pad 7 h for semiconductor package 1 h are arranged alternately, and at the same time, are staggered so that pad 7 h is located outside pad 7 f , when viewed from the package body. A memory module 110 is shown in FIG. 4 in its entirety.
[0044] Pad 7 h and pad 7 f corresponding respectively to the upper and lower semiconductor packages are not arranged in parallel in two distant rows as shown in FIGS. 13 and 14 but arranged in an alternate combination in a staggered manner. Therefore, horizontal width of a region occupied on substrate 4 by a set of vertically stacked semiconductor packages is not as large as that shown in FIGS. 13 and 14. Thus, as shown in FIG. 4, as in a conventional example, nine semiconductor packages can be arranged per one layer on one side of one substrate 4 with a dimension determined in accordance with the conventional standard.
[0045] In addition, as shown in FIG. 5, assume that lead 3 h of upper layer semiconductor package 1 h has 3 portions, that is, a lead drawn-out portion 31 h , a lead downward portion 32 h and a lead foot portion 33 h , and that lead 3 f of lower layer semiconductor package if has 3 portions, that is, a lead drawn-out portion 31 f , a lead downward portion 32 f and a lead foot portion 33 f . Here, an inner surface 35 h of lead downward portion 32 h of lead 3 h is positioned outside an outer surface of lead downward 32 f of lead 3 f . Therefore, even if slight displacement of the relative positions of upper and lower layer semiconductor packages, with one overlying the other, may occur, contact of lead downward portion 32 h of lead 3 h with dambar residual portion 8 f of lead 3 f can be prevented.
[0046] (Second Embodiment)
[0047] A structure of a semiconductor module in a second embodiment according to the present invention will be described. The semiconductor module has semiconductor package if mounted as a lower layer and semiconductor package 1 h mounted as an upper layer on substrate 4 , basically in a similar manner to the first embodiment, except for the shape of a lead of each semiconductor package as shown in FIG. 6. Leads 3 f , 3 h have wide portions 10 f , 10 h respectively in the vicinity of the root when viewed from package body 2 . Dambar residual portions 8 f , 8 h are located in the middle of wide portions 10 f , 10 h respectively. Sides far from package body 2 of leads 3 f , 3 h are provided as narrow portions 11 f , 11 h . Width of the wide portion is 0.3 mm, which is the same as conventional lead width B, while width C of the narrow portion is 0.16 mm.
[0048] In addition to the effect described in the first embodiment, a portion of the lead is provided as a wide portion having the same width as the conventional lead width, whereby, the size of a region to be punched will be the same as in a conventional example (see FIG. 21), as shown in FIG. 7. Thus, a conventional punching apparatus can be used, obviating the need for a new punching apparatus. Moreover, large width at the root portion will increase the strength of the lead itself.
[0049] In the present embodiment, leads of each semiconductor package in both upper and lower layers are provided with wide portions and narrow portions. Meanwhile, only the lead of each semiconductor package in the upper layer may be provided with the wide and narrow portions while the lead of each semiconductor package in the lower layer may have the conventional width, that is, the same width as the wide portion.
[0050] (Third Embodiment)
[0051] Referring to FIG. 8, a semiconductor module in a third embodiment according to the present invention will be described. In the semiconductor module, based on the concept in the first and second embodiments, the number of combinations of upper and lower layer semiconductor packages are increased, and a plurality of those combinations are stacked vertically (a top-to-bottom direction in the drawing) to the main surface of the substrate. In an example of a combination mounted on one surface of substrate 4 as shown in FIG. 8, though two combinations, that is, a combination of semiconductor packages 1 h , 1 f and a combination of semiconductor packages 1 j , 1 i are stacked, three or more combinations may be stacked. Further, the semiconductor packages stacked on one surface do not always have to be a combination of upper and lower layers. For example, a stack in which semiconductor package 1 j of FIG. 8 is absent is possible.
[0052] Thus, larger number of semiconductor packages are mounted per unit area of a substrate, and a semiconductor module of high density and high performance can be obtained. For example, if the module is a memory module, the one with a large capacity can be obtained.
[0053] According to the present invention, even if slight displacement of the relative positions of upper and lower layer semiconductor packages, with one overlying the other, may occur, contact of the lead of the upper layer semiconductor package with the dambar residual portion of the lower layer semiconductor package can be prevented.
[0054] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
|
A semiconductor module includes a substrate having a pad electrode on a surface, a lower layer semiconductor package mounted on the substrate, and an upper layer semiconductor package mounted on the substrate while arranged in a position substantially overlying the former. The pad electrodes connected to the leads of these semiconductor packages are arranged alternately. The lead has a dambar residual portion. An inner surface of a lead downward portion of the upper layer semiconductor package is positioned outside an outer surface of a lead downward portion of the lower layer semiconductor package.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to a tool used to create a joint along the seam of a corner formed by two abutting dry wall panels which form an angle that is greater than ninety degrees.
Predominantly, in dry wall construction, corners are usually about ninety degrees. However, in some types of interiors, corner angles may be considerably greater and pose certain difficulties when closing the seam between the panels. Typically, dry wall seams are closed using a joint compound and joint tape that are worked into the seam area to fill the space between the panels to create a smooth appearing surface for receiving paint or any other suitable wall covering.
An experienced dry wall finisher can close a flat seam between panels, or a ninety degree corner, quickly and efficiently using tools presently available in the trade. However, no tools are available for specifically dealing with wide angle corners and, as a consequence, a great deal of time and effort is wasted in finishing this type of corner joint even by the most skilled workers. This leads to an increase in construction costs.
SUMMARY OF THE INVENTION
An object of the present invention is to improve tools used in closing wide angle corners in dry wall construction.
A still further object of the present invention is to provide a dry wall finishing tool which can be used to rapidly and efficiently close a wide angle corner formed by two abutting panels.
Another object of the present invention is to provide a dry wall tool that will enable someone less than a highly skilled worker to form a quality joint in a wide angle dry wall corner.
Yet another object of the present invention is to reduce the cost of dry wall construction.
These and other objects of the present invention are attained by means of a corner closing tool that includes a thin flexible blade having a top edge, two opposed side edges and a pair of bottom edges that meet at the center of the blade to create a point having an inside or included angle of between 140° and 160°. The blade is bent along a Y-shaped bend line lying along the central axis thereof to create two angularly offset wings that are slanted upwardly from the rear face of the blade towards its front face. The two wings form an interior angle of between 140° and 160°. In use, the blade is centered in a wide angled corner and pressed into conformity with the corner forming panels.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of these and other objects of the present invention, reference should be made to the following detailed description of the invention which is to be read in association with the following drawings wherein:
FIG. 1 is a perspective view showing the tool of the present invention being used to close a corner joint between two sheets of dry wall;
FIG. 2 is a front view of the tool shown in FIG. 1;
FIG. 3 is a side view of the tool;
FIG. 4 is a sectional view taken along line 4--4 in FIG. 2; and
FIG. 5 is an exploded view in perspective showing the parts of the tool.
DESCRIPTION OF THE INVENTION
Turning now to the drawings, there is illustrated a dry wall tool, generally designated 10, which is ideally well suited for use in closing the joint between two wallboard panels 11, 12 where the interior angle between the two panels is between 140° and 160°. This type of corner will herein be referred to as a wide angle corner. As noted above, the seam between the panels is first tightly packed with a joint compound and while the compound is still wet, a strip of suitable joint tape, which is generally paper, is placed in the compound along the length of the seam. The tape is worked into the compound to remove all wrinkles and a second layer of compound is placed over the strip and allowed to dry. Once dry, the joint compound is sanded smooth. If required, a finishing layer of compound may be placed over the smoothed surface which is again sanded before sealing and painting.
Ordinarily, when the seam is between two flat panels lying in the same plane, the compound and strip material can be worked with a flat faced blade to rapidly and efficiently finish the joint. Special tools are also available for finishing standard 90° corners. These special tools all take more or less the same form, wherein two perpendicularly aligned, flat-faced blades are joined together in a shape that complements the corner. No tools, however, are presently available for working wide angle corners, that is, corners having interior angles of between 140° and 160°.
The present tool includes a blade 13, a handle 14 and a blade stiffener 15. The blade preferably is formed from a single sheet of relatively thin, resilient steel having sufficient flexibility so that the blade will flex when pressed into a corner as shown in FIG. 2. The blade portion of the tool has a linear top edge 17 and a pair of opposed side edges 18 and 19 and two angularly offset bottom edges 20 and 21 which intersect at the central axis 23 of the tool to form a point 28. Each bottom edge forms an angle of between 70° and 80° with the axis of the blade so that the interior angle (A) between the edges is about between 140° and 160° with an angle of 150° being preferred.
The blade is bent along a Y-shaped bend line 30 having a center vertical leg 31 aligned with the axis 23 of the blade. The leg extends upward from the point 28 of the blade to about the mid-section of the blade. The legs 32 and 33 of the bend line diverge uniformly from the leg 31 and extend upwardly toward the top edge 17 of the blade before turning upwardly in a vertical direction at 34 and 35 (FIG. 5). The blade on both sides of the bend line is bent uniformly from the back face 36 toward the front face 37 of the blade to form a pair of symmetrical wings 40 and 41. As best seen in FIG. 4, an interior angle (B) of between 140° and 160° is formed by the two upraised wings, with an angle of 150° being preferred.
As can be seen, the bottom edges of the wings are swept upwardly from the point 28 toward the side edges 18, 19 while at the same time folding outwardly from the back face of the blade toward the front face. Accordingly, when the blade is flexed into a wide angle corner as shown in FIG. 1, the blade can be drawn in the direction of the arrow to either smooth the joint compound in the corner or to flatten the joint tape into the seam. The two bottom edges of the blade are bevelled slightly with the bevel sloping from the back face of the blade toward the front face to enhance the tool's ability to work the compound.
Stiffening member 15 is mounted along the top edge of the blade to provide added rigidity to this section. The member is formed from a single sheet of steel that is bent into a U-shaped configuration that complements the shape of the blade. The top edge of the blade is slipped into the open end of the stiffener and is held therein either by mechanically pressing the abutting surface into locking contact or spot welding them together.
Handle 14 has a base section 53 in which a slot 54 is formed. The stiffener and blade assembly are slidably received within the slot. Aligned rivet holes 57, 58 and 59 are provided in the blade, the stiffener and the base section of the handle, respectively. Rivets 60--60 are received in the holes and heads 61--61 are joined to the rivets to secure the three elements of the tool in assembly. The shank 62 of the handle extends outwardly from the blade and is contoured to provide a secure hand grip.
While the invention has been described in the specification and illustrated in the drawings with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the invention without departing from the scope of the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. It is intended that the invention not be limited to the particular embodiments illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling with the description of the claims.
|
A tool used to work joint compound into a wide angle corner formed by two abutting wallboard panels. The blade is formed of flexible sheet metal that is contoured so that it can be pressed into a wide angle corner to work joint compound into the corner seam and close the joint in a rapid and efficient manner.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage of International Application No. PCT/EP2013/074916 filed Nov. 28, 2013, and which claims priority to German Patent Application No. 10 2012 025 290.0 filed Dec. 21, 2012, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present disclosure relates generally to the field of vehicle brake systems. Concretely, an electrohydraulic vehicle brake system with an electromechanical actuator for actuating the brake system is described.
Electromechanical actuators have already been used for some time in vehicle brake systems, for example, for realising an electrical parking brake function (EPB). In the case of electromechanical brake systems (EMB), they replace the conventional hydraulic cylinders at the wheel brakes.
Owing to technical advances, the efficiency of the electromechanical actuators has continually increased. It was therefore considered to use such actuators also for implementing modern driving dynamics control systems. Such control systems include an antilock braking system (ABS), a traction control system (TCS) or an electronic stability program (ESP), also referred to as vehicle stability control (VSC).
WO 2006/111393 A, and corresponding to U.S. Pat. No. 8,540,324 B2, teaches an electrohydraulic brake system having a highly dynamic electromechanical actuator which performs the pressure modulation in the driving dynamics control operation. The electromechanical actuator described in WO 2006/111393 A is provided to act directly on a master cylinder of the brake system. Owing to the high dynamics of the electromechanical actuator, the hydraulic components of the brake system known from WO 2006/111393 A can be reduced to a single 2/2-way valve per wheel brake. To realise wheel-individual pressure modulations, the valves are then actuated individually or in groups in multiplex operation.
However, the minimising to only one valve per wheel brake also results in challenges, such as an undesired pressure equalisation when valves are opened simultaneously. A solution based on a highly dynamic control behaviour is specified for this in WO 2010/091883 A, and corresponding to US Patent Publication No. 2012/013173 A1.
WO 2010/091883 A discloses an electrohydraulic brake system having a master cylinder and a tandem piston accommodated therein. The tandem piston is actuable by means of an electromechanical actuator. The electromechanical actuator comprises an electric motor arranged concentrically with respect to the tandem piston, as well as a transmission arrangement which converts a rotational movement of the electric motor into a translational movement of the piston. The transmission arrangement is composed of a ball screw drive having a ball screw nut coupled in a rotationally fixed manner to a rotor of the electric motor and a ball screw spindle acting on the tandem piston.
A further electrohydraulic brake system having an electromechanical actuator acting on a master cylinder piston is known from WO 2012/152352 A, and corresponding to US Patent Publication No. 2014/197680 A1. This system can operate in a regenerative mode (generator operation).
BRIEF SUMMARY OF THE INVENTION
A regenerative electrohydraulic motor-vehicle brake system and a method for operating such a brake system are to be specified, which have an advantageous functionality in particular from the point of view of safety.
According to one aspect, a method is specified for operating a regenerative electrohydraulic motor-vehicle brake system having a master cylinder that can be supplied with hydraulic fluid from a reservoir, an electromechanical actuator for actuating a piston accommodated in the master cylinder, and a shut-off valve provided between the master cylinder and the reservoir. The method comprises the steps of actuating the electromechanical actuator with the shut-off valve being closed for generating a hydraulic pressure at a wheel brake that is fluidically connected to the master cylinder, and activating a regenerative braking operation including actuating the shut-off valve for opening same, wherein the master cylinder remains fluidically connected to the wheel brake and the electromechanical actuator is actuated in order to at least partially maintain the hydraulic pressure at the wheel brake.
It should be pointed out that the actuating of the electromagnetic actuator and the activating of the regenerative braking operation can take place substantially simultaneously or in a (for example temporally) fixed sequence. The activation step can in this case precede or else follow the actuating step. The activation step can in particular comprise the additional switching-on of an electrical generator. According to one implementation, the building-up of the hydraulic pressure is started before the braking effect of the regenerative braking operation has fully developed. Since a certain time can pass from the instant of the additional switching-on of the generator up to the development of the latter's braking effect, the regenerative braking operation can be activated before or simultaneously with the actuating of the electromagnetic actuator in order to obtain an assisting hydraulic braking effect.
The teaching presented here can be used with regard to the wheel brakes of a single vehicle axle. At the at least one other vehicle axle, a brake force by means of conventional hydraulic pressure build-up without generator assistance can take place.
The hydraulic pressure can be set with the shut-off valve being open and with the master cylinder fluidically connected to the wheel brake. Such a setting can be defined, for example, by the relationship between a first fluid volume conveyed by means of the electromechanical actuator in the master cylinder and a second fluid volume escaping into the reservoir via the shut-off valve. The relationship can change in the course of a braking procedure.
According to one implementation, the actuation of the electromechanical actuator with the shut-off valve being open and with the master cylinder fluidically connected to the wheel brake is effected in such a way that a damming-up effect is generated at a throttling point in a fluid connection between the master cylinder and the reservoir. The throttling point can be realised by inserting a throttling element into this fluid connection. The throttling element can be an element with fixedly preset or else adjustable throttling effect.
The sum of a first brake force fraction generated by means of the hydraulic pressure and a second brake force fraction generated by means of the regenerative braking operation (“generator braking force”) can correspond to a brake force requested by the driver. The brake force can be requested by the driver, for example, by actuation of the brake pedal. In this connection, there can be installed one or more sensors which detect a brake pedal actuation, and the output signal of which indicates the requested brake force.
A modulation of the brake force requested by the driver can be realized at least partly via a modulation of the first brake force fraction. Additionally or alternatively to this, a modulation of the brake force requested by the driver can be realized at least partly via a modulation of the second brake force fraction.
In one implementation the brake system further comprises a mechanical actuator for actuating the master cylinder piston. The mechanical actuator can comprise an actuating member coupled or couplable to a brake pedal. In a realisation of this kind, the electromechanical actuator can be actuated in such a way that a force transmission from the actuating member to the piston is prevented. For this purpose, a decoupling device can be provided. The force transmission from the actuating member to the piston can be prevented in different ways. For example, the electromechanical actuator can be actuated in such a way that a gap is maintained in a force transmission path between the actuating member and the piston.
Also provided is a computer program product with program code means for performing the method presented here when the computer program product runs on a processor. The computer program product can be comprised by a motor-vehicle control unit or motor-vehicle control unit system.
A further aspect is directed to a regenerative electrohydraulic motor-vehicle brake system. The brake system comprises a master cylinder that can be supplied with hydraulic fluid from a reservoir, an electromechanical actuator for actuating a piston accommodated in the master cylinder, a first shut-off valve provided between the master cylinder and the reservoir and a control unit or control unit system. The control unit or control unit system is configured to actuate the electromechanical actuator with the first shut-off valve being closed for generating a hydraulic pressure at a wheel brake that is fluidically connected to the master cylinder and to activate a regenerative braking operation including actuating the first shut-off valve for opening same, wherein the master cylinder remains fluidically connected to the wheel brake and the electromechanical actuator is actuated in order to at least partially maintain the hydraulic pressure at the wheel brake.
The piston accommodated in the master cylinder can be directly or indirectly actuated by the electromechanical actuator. For example, the electromechanical actuator can be arranged for direct action on the piston of the master cylinder. For this, it can be mechanically coupled or couplable to the piston. The piston can then be directly actuated by the actuator. Alternatively to this, the electromechanical actuator can cooperate with a cylinder/piston device of the brake system different from the master cylinder and the cylinder/piston device can be fluidically coupled on the outlet side to the piston of the master cylinder. A hydraulic pressure built up in the cylinder/piston device by actuation of the electromechanical actuator can then act on the piston of the master cylinder and hydraulically actuate the piston in the master cylinder. In this configuration, the master cylinder piston can be hydraulically actuated via the hydraulic pressure generated in the cylinder/piston arrangement and with the aid of the electromechanical actuator (indirect actuation).
According to one realisation, the brake system further comprises a throttling point in a fluid connection between the master cylinder and the reservoir. The throttling point be formed by any desired throttling element. According to a first realisation, the throttling point is formed by the first shut-off valve in the open state. In other words, the first shut-off valve can have a certain throttling effect in the open state. According to another realizing, a separate throttling element is provided additionally or alternatively to the first shut-off valve.
A first overall flow resistance between the master cylinder and the wheel brake fluidically connected thereto can be less than a second overall flow resistance between the master cylinder and the reservoir with the shut-off valve being open. This situation can be brought about, for example, by causing a throttling effect in the fluid connection between the master cylinder and the reservoir in a targeted manner
The brake system can have a mechanical actuator for actuating the master cylinder piston. The mechanical actuator in turn can comprise an actuating member coupled or couplable to a brake pedal. In this case, the electromechanical actuator can be actuable in such a way that a force transmission from the actuating member to the piston is preventable.
The brake system can further comprise an electrical machine which is operable as a generator for the regenerative braking operation. The braking energy can be recovered by means of this electrical machine. The recovered braking energy can be used in different ways.
The master cylinder can be fluidically connected to a plurality of wheel brakes. In the fluid connection between the master cylinder and each wheel brake there can be provided in each case at least one second shut-off valve, wherein the second shut-off valves are actuable in multiplex operation for realising a driving dynamics control. Thus, exactly one second shut-off valve (e.g. a 2/2-way valve) per wheel brake can be provided for the driving dynamics control.
According to a first variant, in the brake system presented here, the electromechanical actuator is configured to actuate the master cylinder piston in the context of a brake force boosting. The brake force to be boosted can in this case be exerted on the piston by means of the mechanical actuator. According to another variant, the electromechanical actuator is configured to actuate the piston for brake force generation. This variant can be used, for example, in the context of a brake-by-wire (BBW) operation, in which the brake pedal is (normally) mechanically decoupled from the master cylinder piston. In the case of a brake system designed for BBW operation, the mechanical actuator is used to actuate the piston, for instance, in the event of failure of a BBW component (i.e. in the event of an emergency braking)
Depending on the configuration of the vehicle brake system, the selective decoupling of the brake pedal from the master cylinder piston by means of a decoupling device can occur for different purposes. In the case of a brake system designed according to the BBW principle, apart from a “push-through mode” or an emergency braking operation (in which the brake pedal is coupled to the master cylinder piston via the mechanical actuator), permanent decoupling can be provided. In the case of a regenerative brake system, such a decoupling can take place at least in the context of a regenerative braking operation (generator operation). In other brake systems, the decoupling device and the simulation device can also be completely omitted.
To actuate the electromechanical actuator and optional further components of the vehicle brake system, the brake system can have suitable actuating devices. These actuating devices can comprise electrical, electronic or program-controlled assemblies and combinations thereof. For example, the actuating devices can be provided in a common control unit or in a system comprising separate control units (electronic control units, ECUs).
Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first embodiment of an electrohydraulic vehicle brake system;
FIG. 2 shows a second embodiment of an electrohydraulic vehicle brake system;
FIG. 3 shows a third embodiment electrohydraulic vehicle brake system;
FIG. 4 shows a fourth embodiment electrohydraulic vehicle brake system;
FIG. 5 shows a flow diagram which illustrates an embodiment of a method for operating the electrohydraulic vehicle brake system according to one of the preceding figures; and
FIGS. 6A and 6B show diagrams which illustrate the hydraulic pressure profile and the actuation of the electromechanical actuator.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a first embodiment of a hydraulic vehicle brake system 100 , which is based on the brake-by-wire (BBW) principle. The brake system 100 may (e.g. in the case of hybrid vehicles) be operated in a regenerative mode. For this purpose, there is provided an electrical machine 102 which provides a generator functionality and can be selectively connected to wheels and an energy store, e.g. a battery (not shown).
As illustrated in FIG. 1 , the brake system 100 comprises a master cylinder assembly 104 which can be mounted on a vehicle front bulkhead. A hydraulic control unit (HCU) 106 of the brake system 100 is functionally arranged between the master cylinder assembly 104 and four wheel brakes VL, VR, HL and HR of the vehicle. The HCU 106 is configured as an integrated assembly and comprises a large number of hydraulic individual components, as well as several fluid inlets and fluid outlets. Furthermore, a merely schematically represented simulation device 108 for providing a pedal reaction behaviour in service braking operation is provided. The simulation device 108 can be based on a mechanical or hydraulic principle. In the latter case, the simulation device 108 can be connected to the HCU 106 .
The master cylinder assembly 104 has a master cylinder 110 with a piston 140 accommodated displaceably therein. The piston is configured in the embodiment as a tandem piston with a primary piston 112 and a secondary piston 114 and defines in the master cylinder 110 two hydraulic chambers 116 , 118 separated from one another. The two hydraulic chambers 116 , 118 of the master cylinder 110 are connected to an unpressurised hydraulic fluid reservoir 120 via a respective connection in order to supply them with hydraulic fluid. Each of the two hydraulic chambers 116 , 116 is further coupled to the HCU 106 and defines a respective brake circuit I. and II. In the embodiment, there is provided for the brake circuit I. a hydraulic pressure sensor 122 , which could also be integrated into the HCU 106 .
The master cylinder assembly 104 further comprises an electromechanical actuator 124 as well as a mechanical actuator 126 . Both the electromechanical actuator 124 and the mechanical actuator 126 enable an actuation of the master cylinder piston and for this purpose act on an input-side end face of this piston, to be more precise of the primary piston 112 . The actuators 124 , 126 are configured in such a manner as to be able to actuate the master cylinder piston independently of one another (and separately or jointly).
The mechanical actuator 126 has a force transmission element 128 which is configured in the form of a rod and is able to act directly on the input-side end face of the primary piston 112 . As shown in FIG. 1 , the force transmission element 128 is coupled to a brake pedal 130 . It will be understood that the mechanical actuator 126 may comprise further components which are functionally arranged between the brake pedal 130 and the master cylinder 110 . Such further components can be both of a mechanical and a hydraulic nature. In the latter case, the actuator 126 is configured as a hydraulic-mechanical actuator 126 .
The electromechanical actuator 124 has an electric motor 134 and a transmission 136 , 138 downstream of the electric motor 134 on the drive side. In the embodiment, the transmission is an arrangement composed of a rotatably mounted nut 136 and a spindle 138 in engagement with the nut 136 (e.g. via rolling bodies such as balls) and movable in the axial direction. In other embodiments, toothed rack transmissions or other transmission types can be used.
In the present embodiment, the electric motor 134 has a cylindrical design and extends concentrically with respect to the force transmission element 128 of the mechanical actuator 126 . To be more precise, the electric motor 134 is arranged radially outside with respect to the force transmission element 128 . A rotor (not shown) of the electric motor 134 is coupled in a rotationally fixed manner to the transmission nut 136 , in order to set the latter in rotation. A rotary movement of the nut 136 is transmitted to the spindle 138 in such a manner that an axial displacement of the spindle 138 results. In this procedure, the end side, on the left in FIG. 1 , of the spindle 138 can come into abutment (optionally via an intermediate member) with the end side, on the right in FIG. 1 , of the primary piston 112 and consequently displace the primary piston 112 (together with the secondary piston 114 ) to the left in FIG. 1 . Furthermore, the piston arrangement 112 , 114 can also be displaced to the left in FIG. 1 by the force transmission element 128 , extending through the spindle 138 (configured as a hollow body), of the mechanical actuator 126 . A displacement of the piston arrangement 112 , 114 to the right in FIG. 1 is brought about by means of the hydraulic pressure prevailing in the hydraulic chambers 116 , 118 (upon release the brake pedal 130 and optionally upon motive displacement of the spindle 138 to the right).
In the variant of the master cylinder assembly 104 shown in FIG. 1 , the electromechanical actuator 124 is arranged in such a manner that it can act directly on the piston (to be more precise on the primary piston 112 ) of the master cylinder 110 to build up a hydraulic pressure at the wheel brakes. In other words, the piston 112 of the master cylinder 110 is mechanically actuated directly by the electromechanical actuator 124 .
In an alternative configuration of the master cylinder assembly 104 , the piston of the master cylinder 110 can be hydraulically actuated (not shown in FIG. 1 ) with the aid of the electromechanical actuator 124 . In this case, the master cylinder 110 can be fluidically coupled to a further cylinder/piston device cooperating with the electromechanical actuator 124 . Concretely, the cylinder/piston device coupled to the electromechanical actuator 124 can be, for example, fluidically coupled on the outlet side to the primary piston 112 of the master cylinder 110 in such a manner that a hydraulic pressure generated in the cylinder/piston device acts directly on the primary piston 112 and thus leads to an actuation of the primary piston 112 in the master cylinder 110 . The primary piston 112 is then, in a regulation owing to the hydraulic pressure acting, displaced in the master cylinder 110 to such an extent (displacement to the left in FIG. 1 ) until the hydraulic pressure generated in the master cylinder chambers 116 , 118 corresponds to the hydraulic pressure generated in the additional cylinder/piston device.
As shown in FIG. 1 , a decoupling device 142 is functionally provided between the brake pedal 130 and the force transmission element 128 . The decoupling device 142 enables a selective decoupling of the brake pedal 130 from the piston arrangement 112 , 115 in the master cylinder 110 , for example by interruption of the force transmission path. In the following, the functioning of the decoupling device 142 and of the simulation device 108 is explained in more detail. In this connection, it should be pointed out that the brake system 100 shown in FIG. 1 is based on the principle of brake-by-wire (BBW). This means that, in the context of a normal service braking, both the decoupling device 142 and the simulation device 108 are activated. Accordingly, the brake pedal 130 is decoupled from the force transmission element 128 (and thus from the piston arrangement 112 , 114 in the master cylinder 110 ), and an actuation of the piston arrangement 112 , 114 can take place exclusively via the electromechanical actuator 124 . In this case, the usual pedal reaction behaviour is provided by the simulation device 108 coupled to the brake pedal 130 .
In the context of the service braking, the electromechanical actuator 124 thus performs the brake force generating function. In this case, a brake force requested by depressing the brake pedal 130 is generated by the fact that the spindle 138 is displaced to the left in FIG. 1 by means of the electric motor 134 and as a result the primary piston 112 and the secondary piston 114 of the master cylinder 110 are also moved to the left. In this way, hydraulic fluid is conveyed from the hydraulic chambers 116 , 118 via the HCU 106 to the wheel brakes VL, VR, HL and HR.
The level of the brake force, resulting therefrom, of the wheel brakes VL, VR, HL and HR is set in dependence on a sensor-detected brake pedal actuation. For this purpose, a travel sensor 146 and a force sensor 148 are provided, the output signals of which are evaluated by a control unit (electronic control unit, ECU) 150 driving the electric motor 134 . The travel sensor 146 detects an actuation travel associated with an actuation of the brake pedal 130 , while the force sensor 148 detects an actuation force associated therewith. A drive signal for the electric motor 134 is generated by the control unit 150 in dependence on the output signals of the sensors 146 , 148 (and optionally of the pressure sensor 122 ).
Since the procedures in the case of a service braking have been explained in more detail, the emergency braking operation (“push-through” mode) will now be briefly outlined. The emergency braking operation is, for example, the consequence of the failure of the vehicle battery or of a component of the electromechanical actuator 124 . A deactivation of the decoupling device 142 (and of the simulation device 108 ) in the emergency braking operation enables a direct coupling of the brake pedal 130 to the master cylinder 110 , namely via the force transmission element 128 . The emergency braking is initiated by depressing the brake pedal 130 . The brake pedal actuation is then transmitted via the force transmission element 128 to the master cylinder 110 . Consequently, the piston arrangement 112 , 114 is displaced to the left in FIG. 1 . As a result, for the brake force generation, hydraulic fluid is conveyed from the hydraulic chambers 116 , 118 of the master cylinder 110 , via the HCU 106 , to the wheel brakes VL, VR, HL and HR.
According to a first embodiment, the HCU 106 has, with regard to the driving dynamics control operation (brake control functions such as ABS, TCS, ESP, etc.), a basically conventional structure with a total of 12 valves (in addition to valves used, for example, in connection with the activation or deactivation of the decoupling device 142 and the simulation device 106 ). Since the electromagnetic actuator 124 is then (optionally exclusively) actuated in the context of a brake force generation, the additional control functions are carried out in a known manner by means of the HCU 106 (and optionally a separate hydraulic pressure generator such as a hydraulic pump) A hydraulic pressure generator in the HCU 106 may, however, also be dispensed with. The electromechanical actuator 124 then additionally also performs the pressure modulation in the context of the control operation. A corresponding control mechanism is implemented for this purpose in the control unit 150 provided for the electromechanical actuator 124 .
As shown in FIG. 1 , the brake system 100 further comprises a valve 172 which is configured as a shut-off valve and can be integrated into the HCU 106 . The valve 172 is provided functionally between the hydraulic chamber 116 and the unpressurised hydraulic fluid reservoir 120 . In some embodiments, a further valve of this kind (not shown) can be functionally present between the other hydraulic chamber 118 and the reservoir 120 .
The valve 172 is used for the regenerative braking operation. If the regenerative braking operation is activated during a service braking, the generator 102 is additionally switched on in a known manner In order to be able to fully utilise the generator effect energetically, usually no hydraulic pressure is built up at the wheel brakes VL, VR, HL and HR of the wheels which are braked via the generator 102 . The hydraulic chambers 116 , 118 are for this purpose decoupled from the corresponding wheel brakes VL, VR, HL and HR via the HCU 106 .
During an actuation of the brake pedal 130 , the primary piston 112 and the secondary piston 114 in FIG. 1 then also have to be displaced to the left (typically by means of the electromechanical actuator 124 ) in order to provide sufficient axial clearance for an actuation of the brake pedal 130 . The hydraulic fluid displaced from the hydraulic chambers 116 , 118 is, however, unable to reach the wheel brakes VL, VR, HL and HR in order to be able to utilise the generator braking force to the maximum (i.e. in order not to build up any hydraulic pressure). For this purpose, the valve 172 between the hydraulic chamber 116 and the reservoir 120 (and/or the optionally provided valve between the hydraulic chamber 118 and the reservoir 120 ) are opened. The hydraulic fluid escaping from the hydraulic chambers 116 , 118 can thus reach the unpressurised reservoir 120 .
In the case of a further embodiment according to FIG. 2 , the special valves for the driving dynamics control operation (e.g. the TCS and ESP operation) may be dispensed with in the HCU 106 , except for four valves 152 , 154 , 156 , 158 . In the case of this other embodiment of the HCU 106 , recourse may thus be had to the valve arrangement having only four valves 152 , 154 , 156 , 158 (and the corresponding actuation) known from WO 2010/091883 A or WO 2011/141158 A (cf. FIG. 15). The hydraulic pressure modulation in the control operation then also takes place by means of the electromechanical actuator 124 . In other words, the electromechanical actuator 124 is actuated in this case not only for brake force generation in the context of a service braking, but also, for example, for the purpose of driving dynamics control (thus e.g. in the ABS and/or TCS and/or ESP control operation). Together with the actuation of the electromechanical actuator 124 , your wheel-individual or wheel-group-individual actuation of the valves 152 , 154 , 156 , 158 takes place in multiplex operation. In the implementation shown in FIG. 2 , no further valves for driving dynamics control purposes are present between the valves 152 , 154 , 156 , 158 and the master cylinder.
The multiplex operation may be a time multiplex operation. In this case, generally individual time slots can be preset. One or more of the valves 152 , 154 , 156 , 158 can be assigned in turn an individual time slot, which valves can be actuated once or more than once (for example by changing the switching state from open to closed and/or vice versa) during the corresponding time slot. According to one realisation, each of the valves 152 , 154 , 158 can be assigned exactly one time slot. One or more further valve arrangements (not shown in FIG. 2 ) can be assigned one or more further time slots.
In multiplex operation, for example, initially a plurality of or all of the valves 152 , 154 , 156 , 158 can be opened and simultaneously a hydraulic pressure can be built up at a plurality of or all of the assigned wheel brakes VL, VR, HL and HR by means of the electromechanical actuator 124 . When a wheel-individual target pressure is reached, the corresponding valve 152 , 154 , 156 , 158 then closes time-slot-synchronously, while one or more further valves 152 , 154 , 156 , 158 still remain open until the respective target pressure is reached at those too. In multiplex operation, the four valves 152 , 154 , 156 , 158 are therefore opened and closed individually per wheel or wheel group in dependence on the respective target pressure.
According to one embodiment, the valves 152 , 154 , 156 , 158 are realised as 2/2-way valves and configured, for example, as non-adjustable shut-off valves. In this case, therefore, no opening cross-section can be adjusted, as would be the case for example with proportional valves. In another embodiment, the valves 152 , 154 , 156 , 158 are realised as proportional valves with adjustable opening cross-section.
FIG. 3 shows a more detailed embodiment of a vehicle brake system 100 , which is based on the operating principle explained in connection with the schematic embodiment of FIGS. 1 and 2 . Identical or similar elements have been provided with the same reference symbols as FIGS. 1 and 2 , and their explanation is dispensed with in the following. For the sake of clarity, the ECU, the wheel brakes, the four valve units of the HCU assigned to the wheel brakes, and the generator for the regenerative braking operation have not been shown.
The vehicle brake system 100 illustrated in FIG. 3 also comprises two brake circuits I. and II., two hydraulic chambers 116 , 118 of a master cylinder 110 being respectively assigned again to exactly one brake circuit I., II. The master cylinder 110 has two connections per brake circuit I., II. The two hydraulic chambers 116 , 118 here lead to a respective first connection 160 , 162 , via which hydraulic fluid can be conveyed from the respective chamber 116 , 118 into the assigned brake circuit I., II. Furthermore, each of the brake circuits I. and II. can be connected via a respective second connection 164 , 166 , which leads into a corresponding annular chamber 110 A, 110 B in the master cylinder 110 , to the unpressurised hydraulic fluid reservoir (reference symbol 120 in FIG. 1 ) not shown in FIG. 3 .
Between the respective first connection 160 , 162 and the respective second connection 164 , 166 of the master cylinder 110 there is provided a respective valve 170 , 172 which is realised as a 2/2-way valve in the embodiment. The first and second connections 160 , 162 , 164 , 166 can be selectively connected to one another by means of the valves 170 , 172 . This corresponds to a “hydraulic short circuit” between the master cylinder 110 on the one hand and, on the other hand, the unpressurised hydraulic fluid reservoir (which is then connected to the hydraulic chambers 116 , 118 via the annular chambers 110 A, 110 B). In this state, the pistons 112 , 114 in the master cylinder 110 can be displaced by the electromechanical actuator 124 or the mechanical actuator 126 in a manner substantially free from resistance (“free travel clearance”). The two valves 170 , 172 thus enable, for example, a regenerative braking operation (generator operation). Here, the hydraulic fluid displaced from the hydraulic chambers 116 , 118 upon a conveying movement in the master cylinder 110 is then led not to the wheel brakes, but to the unpressurised hydraulic fluid reservoir, without a hydraulic pressure build-up (usually undesired in the regenerative braking operation) occurring at the wheel brakes. A braking effect is then obtained in the regenerative braking operation by the generator (cf. reference symbol 102 in FIGS. 1 and 2 ).
It should be pointed out that the regenerative braking operation can be implemented by axle. In the case of an axle-based brake circuit configuration, therefore, one of the two valves 170 , 172 can be closed and the other open in the regenerative braking operation.
The two valves 170 , 172 furthermore enable the reduction of hydraulic pressure at the wheel brakes. Such a pressure reduction may be desired in the event of failure (e.g. blocking) of the electromechanical actuator 124 or in the driving dynamics control operation, in order to avoid a return stroke of the electromechanical actuator 124 (e.g. in order to avoid a reaction on the brake pedal). For the pressure reduction also, the two valves 170 , 172 are transferred into their open position, whereby hydraulic fluid can flow out of the wheel brakes, via the annular chambers 110 A, 110 B in the master cylinder 110 , back into the hydraulic fluid reservoir.
Finally, the valves 170 , 172 also enable a refilling of the hydraulic chambers 116 , 118 as well. Such a refilling may be required during a braking procedure in progress (e.g. owing to so-called brake “fading”). For refilling, the wheel brakes are fluidically separated from the hydraulic chambers 116 , 118 via assigned valves of the HCU (not shown in FIG. 3 ). The hydraulic pressure prevailing at the wheel brakes is thus “locked in”. Thereupon, the valves 170 , 172 are opened. Upon a subsequent return stroke of the pistons 112 , 114 provided in the master cylinder 110 (to the right in FIG. 3 ), hydraulic fluid is then sucked out of the unpressurised reservoir into the chambers 116 , 118 . Finally, the valves 170 , 172 can be closed again and the hydraulic connections to the wheel brakes opened again. Upon a subsequent conveying stroke of the pistons 112 , 114 (to the left in FIG. 3 ), the previously “locked in” hydraulic pressure can then be further increased.
As shown in FIG. 3 , in the present embodiment both a simulation device 108 and a decoupling device 142 are based on a hydraulic principle. Both devices 108 , 142 comprise a respective cylinder 108 A, 142 A for receiving hydraulic fluid and a piston 108 B, 142 B accommodated in the respective cylinder 108 A, 142 A. The piston 142 B of the decoupling device 142 is mechanically coupled to a brake pedal (cf. reference symbol 130 in FIGS. 1 and 2 ) not shown in FIG. 3 . Furthermore, the piston 142 B has an extension 142 C extending in the axial direction through the cylinder 142 A. The piston extension 142 C runs coaxially with respect to a force transmission element 128 for the primary piston 112 and is arranged upstream of the latter in the actuating direction of the brake pedal.
Each of the two pistons 108 B, 142 B is biased into its starting position by an elastic element 108 C, 142 D (here in each case a helical spring). The characteristic of the elastic element 108 C of the simulation device 108 defines here the desired pedal reaction behaviour.
As further shown in FIG. 3 , the vehicle brake system 100 in the present embodiment comprises three further valves 174 , 176 , 178 , which are realised here as 2/2-way valves. It will be understood that individual ones of or all of these three valves 174 , 176 , 178 may be omitted in other embodiments in which the corresponding functionalities are not required. Furthermore, it will be understood that all of these valves may be part of a single HCU block (cf. reference symbol 106 in FIGS. 1 and 2 ). This HCU block may comprise further valves (cf. FIG. 4 below).
The first valve 174 is provided, on the one hand, between the decoupling device 142 (via a connection 180 provided in the cylinder 142 A) and the simulation device 108 (via a connection 182 provided in the cylinder 108 A) and, on the other hand, the unpressurised hydraulic fluid reservoir (via the connection 166 of the master cylinder 110 ). Arranged upstream of the connection 182 of the cylinder 108 A is the second valve 176 , which has a throttling characteristic in its let-through position. The third valve 178 , finally, is provided between the hydraulic chamber 116 (via the connection 116 ) and the brake circuit I., on the one hand, and the cylinder 142 A of the decoupling device 142 (via the connection 180 ), on the other hand.
The first valve 174 enables a selective activation and deactivation of the decoupling device 142 (and indirectly also of the simulation device 108 ). If the valve 174 is in its open position, the cylinder 142 A of the decoupling device 142 is hydraulically connected to the unpressurised hydraulic reservoir. In this position, the decoupling device 142 is deactivated in accordance with the emergency braking operation. Furthermore, the simulation device 108 is also deactivated.
The opening of the valve 174 has the effect that, upon displacement of the piston 142 B (as a result of an actuation of the brake pedal), the hydraulic fluid received in the cylinder 142 A can be conveyed into the unpressurised hydraulic fluid reservoir in a manner largely free from resistance. This procedure is substantially independent of the position of the valve 176 , since the latter also has a significant throttling effect in its open position. Thus, in the open position of the valve 174 , the simulation device 108 is also indirectly deactivated.
Upon a brake pedal actuation in the open state of the valve 174 , the piston extension 142 C overcomes a gap 190 towards the force transmission element 128 and consequently comes into abutment against the force transmission element 128 . After the gap 190 has been overcome, the force transmission element 128 is taken along by the displacement of the piston extension 142 C and thereupon actuates the primary piston 112 (and—indirectly—the secondary piston 114 ) in the brake master cylinder 110 . This corresponds to the direct coupling, already explained in connection with FIG. 1 , of brake pedal and master cylinder piston for the hydraulic pressure build-up in the brake circuits I., II. in the emergency braking operation.
By contrast, when the valve 174 is closed (and the valve 178 is closed), the decoupling device 142 is activated. This corresponds to the service braking operation. In this case, upon an actuation of the brake pedal, hydraulic fluid is conveyed from the cylinder 142 A into the cylinder 108 A of the simulation device 108 . In this way, the simulator piston 108 B is displaced against the counterforce provided by the elastic element 108 C, so that the usual pedal reaction behaviour arises. Simultaneously, the gap 190 between the piston extension 142 C and the force transmission element 128 is further maintained. As a result, the brake pedal is mechanically decoupled from the master cylinder.
In the present embodiment, the maintaining of the gap 190 takes place as a result of the fact that the primary piston 112 is moved, by means of the electromechanical actuator 124 , at least as quickly to the left in FIG. 3 as the piston 142 B is moved to the left owing to the brake pedal actuation. Since the force transmission element 128 is coupled mechanically or otherwise (e.g. magnetically) to the primary piston 112 , the force transmission element 128 moves together with the primary piston 112 upon actuation of the latter by means of the transmission spindle 138 . This carrying-along of the force transmission element 128 allows the gap 190 to be maintained.
The maintaining of the gap 190 in the service braking operation requires precise detection of the distance travelled by the piston 142 B (and thus of the pedal travel). For this purpose, a travel sensor 146 based on a magnetic principle is provided. The travel sensor 146 comprises a plunger 146 A which is rigidly coupled to the piston 142 B and to the end of which is attached a magnetic element 146 B. The movement of the magnetic element 146 B (i.e. the distance travelled by the plunger 146 B and piston 142 B) is detected by means of a Hall sensor 146 C. An output signal of the Hall sensor 146 C is evaluated by a control unit (cf. reference symbol 150 in FIGS. 1 and 2 ) not shown in FIG. 3 . Based on this evaluation, the electromechanical actuator 124 can then be activated.
Now to the second valve 176 , which is arranged upstream of the simulation device 108 and can be omitted in some embodiments. This valve 176 has a preset or adjustable throttling function. By means of the adjustable throttling function, for example a hysteresis or other characteristic for the pedal reaction behaviour can be obtained. Furthermore, by selective closing of the valve 176 , the movement of the piston 142 B (when the valves 174 , 178 are closed) and thus the brake pedal travel can be limited.
The third valve 178 enables in its open position the conveying of hydraulic fluid from the piston 142 A into the brake circuit I. or the hydraulic chamber 116 of the master cylinder 110 and vice versa. A conveying of fluid from the piston 142 A into the brake circuit I. enables, for example, a rapid braking (e.g. before the beginning of the conveying action of the electromechanical actuator 124 ), the valve 178 being immediately closed again. Furthermore, when the valve 178 is open, a hydraulic reaction (e.g. of a pressure modulation generated by means of the electromechanical actuator 124 in the driving dynamics control operation) on the brake pedal via the piston 142 B can be obtained.
In a hydraulic line leading to the connection 180 of the cylinder 142 A, there is provided a pressure sensor 148 whose output signal allows a conclusion to be drawn about the actuating force on the brake pedal. The output signal of this pressure sensor 148 is evaluated by a control unit (not shown in FIG. 3 ). Based on this evaluation, an actuation of one or more of the valves 170 , 172 , 174 , 176 , 178 for realising the above-described functionalities can then take place. Furthermore, the electromechanical actuator 124 can be actuated based on this evaluation.
In the brake system 100 shown in FIG. 3 , the HCU 106 shown in FIG. 1 can be used. An exemplary realisation of this HCU 106 for the brake system 100 according to FIG. 3 is shown in FIG. 4 . Here, a total of 12 (additional) valves are provided for realising the driving dynamics control functions, as well as an additional hydraulic pump. In an alternative embodiment, for the brake system 100 shown in FIG. 3 , the multiplex arrangement according to FIG. 2 (with a total of four valves in addition to the valves illustrated in FIG. 3 ) can also be used.
In the embodiments shown in FIGS. 1 to 4 , for the regenerative braking the generator 102 is additionally switched on and one or both of the valves 170 , 172 are opened in order to realise a “free travel clearance” for the primary piston 112 and the secondary piston 114 . Since, from the instant when the generator 102 is additionally switched on until a significant generator braking force is obtained, a certain period of time passes, it may be desirable in some situations (e.g. for rapid braking) to generate at least initially an assisting hydraulic pressure at the wheel brakes VL, VR, HL and HR and thus an assisting braking force. This can be done by actuating the electromechanical actuator 124 with closed valves 170 , 172 and open fluid connection between the master cylinder 110 (i.e. the hydraulic chambers 116 , 118 ) and the wheel brakes VL, VR, HL and HR.
Now the situation may arise where the driver further increases an initial deceleration request which, however, would be completely achievable with the generator braking force. In such a situation, there are consequently many boundary conditions. The vehicle brakes hydraulically, and the wheel brakes VL, VR, HL and HR are subjected to hydraulic pressure. A requested further increase of the braking force can be achieved (only) by means of the generator braking force. In this case, the prevailing hydraulic pressure at the wheel brakes VL, VR, HL and HR should if possible not change (for example not increase, so as not to lessen the generator effect). At the same time, for safety reasons, the fluid connection between the hydraulic chambers 116 , 118 and the wheel brakes VL, VR, HL and HR should remain open. For example, no valves should be switched in this fluid connection, since an incorrect switching of such valves in the HCU 106 could result in a loss of deceleration for the vehicle.
There exists therefore the need to at least be able to retain a hydraulic pressure at the wheel brakes VL, VR, HL and HR or ideally still change it, while simultaneously a free travel clearance takes place. According to the flow diagram 500 , illustrated in FIG. 5 , of an embodiment for operating the regenerative electrohydraulic brake system according to one of FIGS. 1 to 4 two steps are initiated for this purpose.
A first step 502 comprises actuating the electromechanical actuator 124 with the valves 170 , 172 being closed for generating a hydraulic pressure at at least one of the wheel brakes VL, VR, HL and HR. In this way, even before the beginning of the generator braking force, hydraulic pressure can be generated at the wheel brakes VL, VR, HL and HR with the regenerative braking operation activated for a rapid braking It is understood that, for generating this hydraulic pressure, the fluid connection between the hydraulic chambers 1116 , 118 of the master cylinder 110 and the wheel brakes VL, VR, HL and HR must be opened.
Following this step, with the regenerative braking operation activated, an actuation of at least one of the valves 170 , 172 for opening the same takes place. This corresponds to step 504 . During this, the hydraulic chambers 116 , 118 of the master cylinder 110 remain fluidically connected to the wheel brakes VL, VR, HL and HR. Furthermore, the electromechanical actuator 124 is actuated in such a way that the hydraulic pressure at the wheel brakes VL, VR, HL and HR is at least partially maintained. In this connection, it should be pointed out that the regenerative braking operation does not have to comprise all four wheel brakes VL, VR, HL and HR. Rather, the regenerative braking operation may be limited to the front axle (wheel brakes VL and VR) or the rear axle (wheel brakes HL and HR).
In step 504 the speed of the electric motor 134 is utilised to feed at least as much volume of hydraulic fluid from the hydraulic chambers 116 , 118 as flows out via one or both of the valves 170 , 172 into the reservoir 120 . In this connection, owing to the high dynamics of the electric motor 134 , a damming-up effect at a throttling point in the fluid connection between the master cylinder 110 and the reservoir 120 can be utilised. This damming-up effect has the effect that the hydraulic pressure built up at the wheel brakes VL, VR, HL and HR in step 502 is at least maintained or at least only slightly reduced, although the wheel brakes VL, VR, HL and HR are fluidically connected both to the master cylinder 110 and (via the open valve 170 and/or 172 ) to the unpressurised reservoir 120 . A substantial pressure drop at the wheel brakes VL, VR, HL and HR can thus be prevented. The hydraulic pressure at the wheel brakes VL, VR, HL and HR is set, with valve 170 and/or 172 open and fluid communication with the master cylinder 110 , by the relationship between a first fluid volume conveyed by means of the electromechanical actuator 124 in the master cylinder 110 and a second fluid volume escaping via the valve 170 and/or the valve 172 into the reservoir 120 .
The brake force acting as a whole on the vehicle is the sum of a first brake force fraction generated at the wheel brakes VL, VR, HL and HR by means of the hydraulic pressure and a second brake force fraction generated by means of the regenerative braking operation (generator braking force). This sum is set so that it corresponds to a brake force requested by the driver and sensor-detected at the brake pedal. A modulation of the brake force requested by the driver (e.g. an increase or a decrease) can be realized via a modulation of the first brake force fraction and/or a modulation of the second brake force fraction. For example, the electromechanical actuator 124 can be operated in such a way that, to maintain the hydraulic pressure at the wheel brakes VL, VR, HL and HR, exactly the same amount of hydraulic fluid is conveyed from the master cylinder 110 as is discharged into the unpressurised reservoir 120 . If, by contrast, more hydraulic fluid is conveyed from the master cylinder 110 , the hydraulic pressure (and thus the brake force produced by the wheel brakes VL, VR, HL and HR) increases and vice versa.
The throttling point can be realised in the fluid connection between the master cylinder 110 and the reservoir 120 in various ways. On the one hand, a throttling element with fixedly preset or variable throttling cross-section could be inserted into the return line to the reservoir 120 , in which the valve 170 and/or the valve 172 is arranged. In the present embodiments, such an additional component is dispensed with and instead the throttling effect of the valve 170 and/or of the valve 172 in the open state is used to generate the desired damming-up effect. The throttling effect resulting therefrom is chosen in such a way that an overall flow resistance between the master cylinder 110 and the wheel brakes VL, VR, HL and HR is less than an overall flow resistance between the master cylinder 110 and the reservoir 120 (with valve 170 and/or 172 being open).
The procedure proposed here has the advantage that, despite opening at least one of the valves 170 , 172 , an interruption of the hydraulic connection between the master cylinder 110 and the wheel brakes VL, VR, HL and HR (by closing corresponding valves of the HCU 106 ) is not necessary. This is desirable for safety reasons, since a communication error incorrectly not to switch the corresponding shut-off valves of the HCU 106 (e.g. the TCISO valves in FIG. 4 ) would result in a loss of deceleration. Furthermore, the solution presented here can, according to one implementation, be realised without additional components, since the inherent throttling effect of the open valve 170 and/or 172 can be utilised. The gap 190 between the actuation element 128 and the piston extension 142 C can also be maintained in an implementation of the technical teaching presented here. In other words, the brake pedal 130 can be mechanically decoupled from the master cylinder 110 .
A closing of the fluid connection between the master cylinder 110 and the wheel brakes VL, VR, HL and HR can be limited to those cases in which a refilling of the hydraulic chambers 116 , 118 with hydraulic fluid from the reservoir 120 has to take place.
FIGS. 5A and 5B illustrate, by way of example, the pressure profile with respect to time in the master cylinder 110 and at the wheel brakes VL, VR, HL and HR ( FIG. 6A ) as a result of an actuation of the electromechanical actuator 124 with valve 172 open and valve 170 closed ( FIG. 6B ). In this connection, it should be pointed out that a pressure drop in one of the two chambers 116 , 118 affects both brake circuits I., II. owing to the floating master cylinder pistons 112 , 114 .
As illustrated in FIG. 6A at the top, even before the instant t 1 the electromechanical actuator 124 , with valves 170 , 172 closed, was actuated in such a way that a hydraulic pressure of approximately 23 bar is applied to the wheel brakes VL, VR, HL and HR. Owing to the open fluid connection between the master cylinder 110 and the wheel brakes VL, VR, HL and HR, the same hydraulic pressure prevails in the master cylinder 110 (i.e. in the chambers 116 , 118 ). The hydraulic pressure illustrated in FIG. 6A served for a rapid braking in the context of a regenerative braking operation. The regenerative braking operation was activated by additionally switching on the generator 102 . This activation took place in close temporal association with the build-up of the hydraulic pressure illustrated in FIG. 6A .
At the instant t 1 , with the regenerative braking operation still activated, the valve 172 is then opened, while the valve 170 remains closed and the master cylinder 110 remains fluidically connected to the wheel brakes VL, VR, HL and HR. In order to avoid a hydraulic pressure loss at the wheel brakes VL, VR, HL and HR owing to the “fluidic short-circuit” with the unpressurised reservoir 120 , the electromagnetic actuator 124 is actuated, likewise at the instant t 1 , in a suitable manner in order to feed hydraulic fluid from the master cylinder 110 into the brake circuits I., II. This is illustrated in FIG. 6B by the corresponding feed travel of the transmission spindle 138 .
At the instant t 2 , the valve 172 is then closed again and the actuation of the electromechanical actuator 124 ends. Simultaneously, the fluid connection between the master cylinder 110 and the wheel brakes VL, VR, HL and HR remains open and the regenerative braking operation is activated. The brake force requested by the driver is therefore still realised by a first brake force fraction which is generated by means of the hydraulic pressure, and a second brake force fraction which arises from the generator braking force.
As illustrated in FIG. 6A , during the open period of the valve 172 , the brake pressure at the wheel brakes VL, VR, HL and HR can be modulated (here increased), in order to fulfil a corresponding driver's wish (here for increasing the brake force). Thus, in spite of the “fluidic short-circuit” between the wheel brakes VL, VR, HL and HR, no loss of hydraulic pressure occurs during the open period of the valve 172 . This proves that the electric motor 134 has sufficiently high dynamics, i.e. can be operated at sufficiently high rotational speed, to realise the required damming-up pressure at the open valve 172 . Thus, during the entire regenerative braking procedure illustrated in FIGS. 6A and 6B , the wheel brakes VL, VR, HL and HR remain fluidically connected to the master cylinder 110 via the HCU 106 . This is a desirable measure for safety reasons.
In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.
|
The invention relates to a technique for operating a regenerative electrohydraulic motor vehicle brake system comprising a master cylinder that can be supplied with a hydraulic fluid from a reservoir, an electromechanical actuator for actuating a piston accommodated in the master cylinder and a stop valve provided between the master cylinder and the reservoir. According to an aspect of this technique, the method comprises the step of controlling the electromechanical actuator when the stop valve is closed to generate a hydraulic pressure on a wheel brake that is fluidically connected to the master cylinder. The method further comprises the step of activating a regenerative brake operation and of controlling the stop valve to open, the master cylinder remaining fluidically connected to the wheel brake and the electromechanical actuator being controlled to maintain the hydraulic pressure on the wheel brake at least to some extent.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 61/791,737, filed Mar. 15, 2013, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
The present disclosure relates generally to methods of assessing asphaltene inhibitor/dispersant efficiency in crude oil applications.
BACKGROUND
Crude oil from geological formations commonly contains solids, typically as one or more of waxes, asphaltenes, sulfur, minerals (e.g., scale), and hydrates. When crude oil is transported via pipeline, e.g., from a geological formation to a wellhead or from a wellhead or a storage vessel to a refinery via pipeline, changes in the pressure, temperature, composition, etc. (or other parameters of the flowing crude oil) can lead to deposition of solids on the pipe walls and surfaces. The deposition of these solids from the crude oil onto the interior surfaces of the pipes can have a drastic and negative impact on the oil flow through these pipes.
Asphaltenes, in particular, make up one of the most polar fractions of crude oil, and often will precipitate and deposit on pipe surfaces upon an external stress, such as temperature, pressure and/or compositional changes in the oil (resulting from blending or physical/chemical processing). Asphaltene deposits can plug downhole tubulars, well-bores, choke off pipes and interfere with the functioning of separator equipment.
Traditionally, in the petroleum industry, the problems caused by the deposition of asphaltenes have been controlled by use of asphaltene inhibitors and/or dispersants. Assessment of inhibitor effectiveness has traditionally included down-hole processes, complicated and/or costly lab techniques or non-deposition based methods. Screening through such processes is generally slow and only allows for the screening of one or a few asphaltene inhibitors at a time, or possibly even irrelevant when precipitation-based methods are used. The depositions methods developed to date are too cumbersome and/or costly to make high throughput screening practical.
The asphaltene dispersancy test is currently the industry standard for asphaltene inhibitor evaluation and selection. The test, however, is a precipitation test and gives no information about deposition. Other available tests are expensive for even a single data point, require large quantities of crude oil, and/or take at least several hours to complete. Thus, there exists a need for a reliable, fast, and cost-effective method to assess asphaltene inhibitor efficacy.
SUMMARY
In one aspect, disclosed is a method of assessing asphaltene inhibitor/dispersant efficacy in a crude oil, the method comprising: a) weighing a first coupon; immersing the first coupon or a portion thereof into a first sample for a first selected time period, the first sample comprising an aliquot of the crude oil; adding a precipitant to the first sample within the first selected time period; removing the first coupon from the first sample at the end of the first selected time period; and drying and weighing the first coupon; b) weighing a second coupon; immersing the second coupon or a portion thereof into a second sample for a second selected time period, the second sample comprising an aliquot of the crude oil and an asphaltene inhibitor/dispersant; adding a precipitant to the second sample within the second selected time period; removing the second coupon from the second sample at the end of the second selected time period; and drying and weighing the second coupon; c) determining the weight of asphaltenes deposited on the first coupon and the weight of asphaltenes deposited on the second coupon; and d) determining the % asphaltene deposition inhibition via equation (1),
%
Inhibition
=
100
×
(
1
-
Weight
of
asphaltenes
deposited
on
the
second
coupon
Weight
of
asphaltenes
deposited
on
the
first
coupon
)
.
(
1
)
In certain embodiments, after the coupons are removed from respective samples and dried, the coupons are rinsed (e.g., with heptane), the rinsed coupons dried, and then weighed.
In certain embodiments, the volume of crude oil in the first sample ranges from 5-20 mL, and the volume of crude oil in the second sample ranges from 5-20 mL. The volume used for each sample is preferably equal.
In certain embodiments, the first selected time period ranges from 1 hour to 33 days, and the second selected time period ranges from 1 hour to 33 days. In a preferred embodiment, the first selected time period and the second selected time period are of the same or substantially the same duration.
In some embodiments, each of step a) and step b) individually comprise three sequential events: precipitant addition, soak time after precipitant addition, and drying time after soaking. The three events may have the following length: precipitant addition time, >0 min to 48 hours; soak time, 30 min to 30 days; and dry time, 1 hour to 48 hours. In certain embodiments, the events have the following length: precipitant addition time, 3 hours; soak time, 48 hours; and dry time, 24 hours. In some aspects, the same event occurring in each of steps a) and b) is of the same or substantially the same duration (e.g., the precipitant addition time is the same or substantially the same in each of steps a) and b)). For step a), it is to be understood that the events of precipitant addition and soak time occur in the first selected time period; and for step b), it is to be understood that the events of precipitant addition and soak time occur in the second selected time period.
In another embodiment, after the sequential steps of precipitant addition, soak time after precipitant addition, and drying time after soaking, the following sequential steps occur: rinsing of the coupons (e.g., with heptane), drying of the rinsed coupons, and weighing of the rinsed and dried coupons.
In certain embodiments, the volume of precipitant added to each of the first and second samples is determined by titration of the crude oil with the precipitant prior to assessing the asphaltene inhibitor/dispersant efficacy. In certain embodiments, the volume of precipitant added to each of the first and second samples corresponds to the Onset Volume±20%. In certain embodiments, the precipitant is added dropwise to each of the first and second samples over the first and second selected time periods. In certain embodiments, the precipitant is added in fractions to each of the first and second samples over the first and second selected time periods. In certain embodiments, the precipitant is added all at once to each of the first and second samples over the first and second selected time periods.
In certain embodiments, steps a) and b) are conducted in parallel such that the first and second selected time periods are of the same or substantially the same duration and occur together in real time.
In certain embodiments, the first sample and the second sample are each substantially closed to the atmosphere during the first and second selected time periods.
In certain embodiments, each of the first and second samples are stirred or agitated during at least a portion of the first and second selected time periods.
In certain embodiments, the asphaltene inhibitor/dispersant is selected from the group consisting of aliphatic sulphonic acids; alkyl aryl sulphonic acids; aryl sulfonates; lignosulfonates; alkylphenol/aldehyde resins and similar sulfonated resins; polyolefin esters; polyolefin imides; polyolefin esters with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin amides; polyolefin amides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin imides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; alkenyl/vinyl pyrrolidone copolymers; graft polymers of polyolefins with maleic anhydride or vinyl imidazole; hyperbranched polyester amides; polyalkoxylated asphaltenes, amphoteric fatty acids, salts of alkyl succinates, sorbitan monooleate, polyisobutylene succinic anhydride; and combinations thereof.
In certain embodiments, the precipitant is a liquid precipitant selected from the group consisting of alkane solvents. In certain embodiments, the liquid precipitant is heptanes, hexanes, pentanes, or any combination thereof.
In certain embodiments, the precipitant is a gas precipitant selected from the group consisting of methane, ethane, propane, butane, carbon dioxide, nitrogen, argon, helium, neon, krypton, xenon, and any combination thereof.
In certain embodiments, each sample is heated to a temperature of −15° C. to +80° C. In some embodiments, each sample may be heated to a temperature of −15° C. to +300° C. In certain embodiments, each sample is under a pressure of atmospheric to 20,000 psi. In some embodiments, each sample is under a pressure of atmospheric to 30,000 psi. In certain embodiments, each sample is at ambient temperature and pressure.
In certain embodiments, each sample further comprises one or more constituents selected from the group consisting of paraffin inhibitors, corrosion inhibitors, scale inhibitors, emulsifiers, water clarifiers, dispersants, emulsion breakers, hydrogen sulfide scavengers, gas hydrate inhibitors, biocides, pH modifiers, surfactants, brine, water, and solvents.
In certain embodiments, the coupons are carbon steel coupons, iron coupons, stainless steel coupons, glass coupons, coupons comprised of synthetic or natural polymers, coupons comprised of any metal, coupons comprised of any mineral, coupons comprised of wood, or any combination thereof. In a preferred embodiment, the coupons are carbon steel or stainless steel.
In certain embodiments, the coupons are cylindrical coupons, rectangular prism coupons, spherical coupons, or hexagonal prism coupons.
In certain embodiments, the method is carried out on-site at an oil field.
In another aspect, disclosed is a method of assessing a solvent efficacy for remediating asphaltene deposition, comprising: a) providing a coupon having asphaltene deposit, said coupon optionally provided by the precipitation/soaking procedure described herein; b) weighing the coupon; c) immersing the coupon in a solution comprising at least one solvent, wherein the coupon is immersed for a selected time period; d) removing the coupon from the solution at the end of the selected time period, and drying and weighing the coupon; and e) determining the % asphaltene deposition removal via equation (2),
%
Removal
=
100
×
(
1
-
Weight
of
asphaltenes
on
coupon
after
immersing
Weight
of
asphaltenes
on
coupon
before
immersing
)
.
(
2
)
In certain embodiments, after the coupon is removed from the solution and dried, the coupon is rinsed, the rinsed coupon dried, and then weighed. In other embodiments, the coupon may be removed and the deposit may be isolated for further analysis using other analytical methods to qualify and quantify the deposit.
In certain embodiments, the solvent is selected from aromatic solvents such as toluene, xylene, benzene, and HAN (heavy aromatic naphtha). In certain embodiments, any solvent in which asphaltenes are soluble can be used, or any combination thereof. In addition, the solvents can be used in conjunction with a variety of dispersants (surface active agents).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an exemplary setup useful for assessing the efficacy of asphaltene inhibitors/dispersants at preventing and/or reducing deposition of asphaltenes.
DETAILED DESCRIPTION
Disclosed herein are methods for assessing the efficacy of asphaltene inhibitors/dispersants at preventing and/or reducing deposition of asphaltenes from a liquid (e.g., crude oil). The efficiency of asphaltene inhibitors/dispersants is assessed by comparing the mass of asphaltenes deposited on a coupon in the presence and absence of inhibitors/dispersants. Also disclosed herein are methods for designing a cleaning program to remediate an asphaltene deposition problem in the field. A deposition test can be conducted in multiplicate using untreated (oil), and the resulting asphaltene deposit coated coupons can be used in a second experiment aimed at assessing the cleaning power of a variety of solvent-dispersant/cleaner packages.
The disclosed methods provide several advantages over currently available screening methods. Specifically, the methods are inexpensive, convenient, and reliable compared to currently available technologies. The methods can be used to rapidly screen a large number of samples, and have the flexibility to account for changing field parameters on a case by case basis (e.g., the effects of gas composition, shear rate, and temperature). The methods can be used to collect a multitude of data points in a short time period (e.g., 4 hours) and require a minimal volume of liquid per data point (e.g., 5-20 mL of crude oil).
1. Definitions
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present invention. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.
The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “and” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of” and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.
“Asphaltene inhibitor/dispersant,” as used herein, refers to a chemical or composition that prevents or reduces asphaltene precipitation from a crude oil and/or deposition of asphaltene on surfaces in contact with a crude oil, or a chemical used to help in the removal of an asphaltene deposit already formed on a surface.
“Deposition,” as used herein, refers to the coating of agglomerated materials on the surface of a material, such as an interior wall of a pipe or tubing.
“Precipitant,” as used herein, refers to a liquid or gas that triggers asphaltene destabilization from crude oil.
“Precipitation,” as used herein, refers to the agglomeration of solids which may remain suspended in the bulk fluid fraction, or settle down by gravity, but do not physically attach to any surface.
For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the number 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.
2. Method of Assessing Asphaltene Inhibitor/Dispersant Efficacy
In one aspect, disclosed herein are methods for assessing the efficacy of asphaltene inhibitors/dispersants at preventing and/or reducing deposition of asphaltenes from a liquid (e.g., crude oil). The efficiency of asphaltene inhibitors/dispersants is assessed by comparing the mass of asphaltenes deposited on a coupon in the presence and absence of inhibitors/dispersants. The deposition may be triggered by addition of a precipitant to the liquid sample.
In general, to conduct an efficiency test of an asphaltene inhibitor/dispersant with a particular crude oil, a coupon is immersed in one container containing crude oil and a stir bar, and another coupon is immersed in a second container containing crude, a stir bar, and the asphaltene inhibitor/dispersant to be evaluated. A liquid precipitant or gas precipitant is then added to the crude oil in each container in order to trigger asphaltene deposition on the coupon surface.
At the end of the experiment, the asphaltene tarred coupons are removed from the crude/precipitant mixture, dried, and weighed. Optionally, the coupons are rinsed and dried before being weighed. The amount of asphaltenes precipitated at the surface of the coupon is determined by comparing the weight of the coupon before the experiment to the weight at the end of the experiment. The weight of asphaltenes collected on the coupon surface for a treated oil (i.e., oil dosed with an asphaltene inhibitor/dispersant) is compared with that of an untreated oil. From these two values, the inhibitor/dispersant efficiency is assessed using the following formula:
%
Inhibition
=
100
×
(
1
-
Weight
of
asphaltenes
deposited
from
treated
sample
Weight
of
asphaltenes
deposited
from
blank
)
The amount of asphaltene deposited onto the coupon depends upon the efficacy of the asphaltene inhibitor. An efficient and effective asphaltene inhibitor will result in less asphaltene mass deposited from the treated samples and result in a higher % inhibition number from the equation above. In turn, an ineffective or non-efficient or poor asphaltene inhibitor will result in an amount of asphaltene amount or weight deposited to the coupon that is closer to the weight of the control coupon (i.e., the coupon that has been placed in the container with no asphaltene inhibitor).
During the experiment, the precipitant can be added in any selected fashion (e.g., drop wise, all at once, or in several fractions over the duration of the experiment). A suitable amount of precipitant to be added to the crude oil during the experiment can be determined by titration of the oil with the precipitant prior to starting the experiment. The amount of precipitant necessary to initiate asphaltene precipitation (called Onset Volume) is used as a guideline for the total amount of precipitant to be added to the oil during the deposition test. Generally, a volume of precipitant corresponding to the Onset Volume±20% will be used during the deposition test.
The duration of the experiment can be conducted over any selected time period. In certain embodiments, the time ranges from minutes to days (e.g., 1 hour to 33 days). Preferably, the experiment includes the sequential steps of precipitant addition, soaking after precipitant addition, and drying. The three events may have the following length: precipitant addition, >0 min to 48 hours (e.g., 3 h); soak time, 30 min to 30 days (e.g., 48 h); and dry time, 1 hour to 48 hours (e.g., 24 h). In some aspects, the same events in each of steps a) and b) are of the same or substantially the same duration (e.g., the precipitant addition time is the same or substantially the same in steps a) and b); preferably the soak time is the same or substantially the same in steps a) and b); and the drying time following the soak time may be the same or substantially the same in steps a) and b)).
For step a), it is to be understood that the events of precipitant addition and soak time occur in the first selected time period; and for step b), it is to be understood that the events of precipitant addition and soak time occur in the second selected time period.
In another embodiment, after the sequential steps of precipitant addition, soak time after precipitant addition, and drying time after soaking, the following sequential steps occur: rinsing of the coupons (e.g., with heptane), drying of the rinsed coupons, and weighing of the rinsed and dried coupons.
In certain embodiments, the deposition tests on treated and untreated samples are conducted simultaneously in parallel to limit experimental errors. In some embodiments, the containers of crude oil with the immersed coupons are kept closed to the atmosphere as well as possible during the entire addition of precipitant to avoid evaporation and loss of crude or precipitant.
The tests can be conducted at any selected temperature, agitation, and pressure to simulate field conditions. In certain embodiments, the tests are conducted at ambient temperature and pressure. In certain embodiments, the tests are conducted at non-ambient temperature and pressure. In certain embodiments, the tests are conducted at −15 to +80° Celsius; atmospheric to 20,000 psi; shear 0 to 10000 Pascals. In some embodiments, the tests are conducted at −15 to +300° Celsius; atmospheric to 30,000 psi; shear 0 to 10000 Pascals.
Suitable liquid precipitants include alkane solvents (e.g., heptanes, hexanes, pentanes or any liquid alkane, branched, cyclic or linear).
Suitable gas precipitants include methane, ethane, propane, butane, carbon dioxide, nitrogen, argon, helium, neon, krypton, and xenon.
Suitable asphaltene inhibitors/dispersants that can be evaluated include, but are not limited to, aliphatic sulphonic acids; alkyl aryl sulphonic acids; aryl sulfonates; lignosulfonates; alkylphenol/aldehyde resins and similar sulfonated resins; polyolefin esters; polyolefin imides; polyolefin esters with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin amides; polyolefin amides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin imides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; alkenyl/vinyl pyrrolidone copolymers; graft polymers of polyolefins with maleic anhydride or vinyl imidazole; hyperbranched polyester amides; polyalkoxylated asphaltenes, amphoteric fatty acids, salts of alkyl succinates, sorbitan monooleate, and polyisobutylene succinic anhydride.
FIG. 1 shows an exemplary device configuration useful for assessing the efficacy of asphaltene inhibitors/dispersants at preventing and/or reducing deposition of asphaltenes from a liquid (e.g., crude oil). The setup may be used to test the inhibitor/dispersant at atmospheric pressure and temperature, or may be adapted to be a pressurized and temperature controlled apparatus. As shown, the setup 100 includes a syringe pump 110 used to inject an exact same amount of precipitant at an exact same time to each of the vials 140 . The setup further includes syringes 120 containing a precipitant to be added to the vials 140 . The precipitant is added to the vials via tubing 130 (e.g., PEEK tubing). The vials 140 each include a vial cap 143 that holds a test coupon 145 , which is immersed in a crude oil-precipitant mixture 147 . The vials are each equipped with a stir bar, which is controlled by a stir plate 150 that controls the shear inside the vials. The setup may be adapted to test more or less samples from that depicted by using additional or fewer syringes and vials, for example.
3. Method of Assessing Cleaning Program to Remediate an Asphaltene Deposition
In another aspect, disclosed is a method of assessing a solvent efficacy for remediating asphaltene deposition. The method can be used to design a cleaning program to remediate an asphaltene deposition problem in the field.
In one exemplary embodiment, a deposition test would be conducted in multiplicate using untreated (oil), and the resulting asphaltene deposit coated coupons used in a second experiment aimed at assessing the cleaning power of a variety of solvent-dispersant/cleaner packages. The asphaltene coated coupons can be immersed in agitated cleaner solutions and the kinetics of dissolution assessed for each solvent in order to pick the best possible solvent for the remediation job.
In certain embodiments, the solvent is selected from aromatic solvents such as toluene, xylene, benzene, and HAN (heavy aromatic naphtha). In certain embodiments, the solvent may be any solvent in which asphaltenes are soluble, or a combination thereof. In addition, the solvents can be used in conjunction with a variety of dispersants (surface active agents).
4. Examples
The foregoing may be better understood by reference to the following examples, which are intended for illustrative purposes and are not intended to limit the scope of the invention.
EXAMPLE
The following example describes an actual experiment that was conducted with the disclosed method using a setup according to FIG. 1 . All data and results were collected and obtained via the procedure described. The objective of the experiment described was to evaluate and compare the performance of four Inhibitors (A, B, C, and D), when used to treat a sample of crude oil from the Gulf of Mexico (GOM crude oil).
Equipment & Materials
The following equipment and materials were used: Analytical Balance; Multicapacity delivery syringe pump; Multi-position magnetic stirrer (10-channel); Dropper pipette; Cylindrical glass vials with customized caps (quantity: 10); Syringes (quantity: 10); Attachable syringe needles with PEEK tubing (quantity: 10); Small magnetic stir bars (quantity: 10); Metal coupons (quantity: 10); GOM oil sample (130 mL); Heptane (excess); and Inhibitors (A, B, C, and D).
Experimental Procedure
Prior to performing the experiment, the precipitant onset volume for the oil sample designated for testing was determined, using heptane solvent as the liquid precipitant. The measured onset volume was approximately 51% dilution with heptane for the GOM oil sample. The test sample components were then determined based on this value.
To prepare the test equipment for this experiment, the mass of ten clean steel coupons was measured and recorded for each. The syringes to be used for heptane delivery were then assembled using PEEK tubing and needle attachments, followed by withdrawing 17 mL heptane into each syringe. Any visible air was removed from all syringes to ensure accurate and uniform volume delivery, and then all ten syringes were secured onto the pump rack.
The test samples were prepared by first distributing 13 mL GOM crude oil to each of ten glass sample vials, followed by injection of Inhibitor to the appropriate vials, as indicated in Table 1.
TABLE 1
Inhibitor Treatment of Samples
Sample No.
Inhibitor (1000 ppm)
1
Untreated
2
Untreated
3
Inhibitor A
4
Inhibitor A
5
Inhibitor B
6
Inhibitor B
7
Inhibitor C
8
Inhibitor C
9
Inhibitor D
10
Inhibitor D
After Inhibitor dosing was completed, a magnetic stir bar was added to each sample vial, followed by the attachment of each metal coupon to the inside of the appropriate vial cap. The coupon-cap assemblies were then carefully affixed onto the corresponding sample vials, allowing the coupons to become submerged into the sample fluid. Once the caps were tightly secured, the sample vials were positioned onto the 10-channel magnetic stirrer, followed by activation of the stirrer (approx. 180 rpm). The PEEK tubing of the pre-filled syringes was then inserted into the cap of each sample vial, and adjusted to ensure uniform positioning and airtight. To initiate the experimental run, the syringe pump was programmed to deliver a volume of 17 mL (per syringe), at a rate of 3 mL per hour, resulting in a heptane addition time of 5.67 hours.
Once heptane delivery was completed, the assembly was left for an additional 144 hours, allowing the coupons to soak in the sample fluid with continued agitation (approx. 180 rpm). After completion of the soak period, the stir agitation was halted and each coupon-cap assembly was cautiously removed from the sample vials, avoiding any contact between coupons and the vial wall. The coupons were then detached from the vial caps, and allowed to air-dry for 24 hours. Once dry, each coupon was individually rinsed with heptane solvent, using a dropper pipette. The coupons were rinsed in a drop-wise manner until no visible oil discoloration was present in the wash solvent, then allowed to dry for 5 minutes. The mass of each coupon was then measured and recorded.
Data and Results
To determine the mass of deposit obtained on each coupon, the initial coupon mass was subtracted from the final coupon mass. Inhibition was determined using Equation 1, where the denominator is the mean of the deposit mass obtained on both untreated sample coupons. The results are reported below in Table 2. Each condition was run in duplicate for repeatability evaluation.
%
Inhibition
=
100
×
(
1
-
Mass
of
asphaltenes
deposited
on
coupon
from
treated
sample
Mean
mass
of
asphaltenes
deposited
on
coupon
from
untreated
sample
)
(
Equation
1
)
TABLE 2
Mass Results of Asphaltene Deposits on Coupons
Sample No.
Inhibitor (1000 ppm)
Deposit Mass (g)
Inhibition (%)
1
Untreated
0.0145
NA
2
Untreated
0.0112
NA
3
Inhibitor A
0.0085
33.85
4
Inhibitor A
0.0094
26.85
5
Inhibitor B
0.0066
48.64
6
Inhibitor B
0.0068
47.08
7
Inhibitor C
0.0079
38.52
8
Inhibitor C
0.0081
36.96
9
Inhibitor D
0.0049
61.87
10
Inhibitor D
0.0050
61.09
CONCLUSION
Based on the results obtained, the most effective Inhibitor for the GOM oil sample was Inhibitor D, which resulted in greater inhibition than all other samples for both duplicate test samples. The results also indicate that Inhibitor A is the least effective Inhibitor for the GOM oil sample, since both samples treated with this Inhibitor displayed the least inhibition of all other treated samples. The results do indicate that all coupons of samples treated with an Inhibitor obtained less asphaltene deposit (mass) than the coupons of untreated samples. Thus, the disclosed method is useful for assessing asphaltene inhibitor/dispersant efficiency in crude oil applications.
Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and whole values) subsumed therein.
Furthermore, the invention encompasses any and all possible combinations of some or all of the various embodiments described herein. Any and all patents, patent applications, scientific papers, and other references cited in this application, as well as any references cited therein, are hereby incorporated by reference in their entirety. It should also be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
|
Methods of assessing asphaltene inhibitor/dispersant efficiency are disclosed. Also disclosed are methods of assessing solvent/dispersant/cleaner efficacy for remediating asphaltene deposition. The methods are useful in facilitating the production, transportation, storage, and separation of crude oil and natural gas, and more particularly, for preventing the undesired deposition of asphaltene from crude oil.
| 2
|
FIELD OF THE INVENTION
[0001] The field of the present invention is communication systems, and particularly, coherent detection with digital signal procession.
[0002] The ever increasing bandwidth demand has been driving communication systems to higher capacities. Therefore, there is a strong motivation to enhance spectral efficiency to increase the total capacity. Employing optical orthogonal frequency division multiplexing (O-OFDM) modulation to transmit signals can realize high-spectral efficiency and long distance transmission. To achieve high receiver sensitivity with coherent detection based on digital signal procession, the bandwidth of the analog to digital converter (ADC) and the sample rate may be high. Usually, the ADC bandwidth may have two times of the bit rate of the signal, and the sampling rate may be four times of the bit rate. For example, if each subcarrier of the OFDM signal is 25 Gbaud Quadrature Phase Shift Keyed (QPSK), the ADC bandwidth should be 50 GHz and the sample rate should be 100 GSa/s to obtain optimum results. However, an ADC with these specifications may not available. Therefore it would be advantageous to reduce the ADC bandwidth and sample rate while maintaining the same performance.
SUMMARY OF THE INVENTION
[0003] Aspects of the present invention employ optical orthogonal frequency division multiplexing (O-OFDM) to transmit signals realizing high-spectral efficiency over long distances.
[0004] In one aspect of the present invention include apparatus and methods for transmitting and receiving signals in communication systems. A multicarrier generator generates a multicarrier signal. An optical demultiplexer separates the multicarrier signal into separate multicarrier signals. At least one QPSK modulator modulates signals from the separate multicarrier signals. An optical multiplexer combines the QPSK modulated signals into a multiplexed signal. The multiplexed signal is then transmitted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 illustrates a schematic diagram of a transmitter and receiver according to aspects of the present invention.
[0006] FIG. 2 illustrates a schematic diagram of digital signal procession for a coherent receiver according to aspects of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0007] Aspects of the present invention employ optical orthogonal frequency division multiplexing (O-OFDM) to transmit signals realizing high-spectral efficiency over long distances.
[0008] FIG. 1 illustrates a schematic diagram of a transmitter and receiver according to aspects of the present invention. A laser 101 generates a continuous lightwave. The laser 101 may be a distributed feedback type laser diode DFB-LD, which may have a wide line width. For a 100 Gbit/s QPSK, a line width smaller than 2 MHz is sufficient. Although line widths greater than 2 MHz may also be sufficient. Alternatively, the laser source 101 may be a tunable external laser with a narrow line width and low phase noise which may be preferred for high level modulation format signals. A multicarrier generator 102 receives the lightwave and generates a multicarrier signal. This multicarrier signal may be generated by a few different schemes. For example, a cascade modulator may be driven by a sinusoidal wave source and cascaded phase modulators. There may be over ten subcarriers with a frequency spacing f. To separate the optical subcarrier and, subsequently route them to different ports, an optical demultiplexer may be employed 103 . This optical demultiplexer 103 may be an array waveguide grating, optical fiber Bragg grating, or other optical demultiplexer as known in the art. Each subcarrier from the respective output ports of the optical demultiplexer 103 may be modulated by using an optical I/O modulator 104 . In particular, the optical I/O modulator 104 generates QPSK signals. These QPSK signals may have a non-return-to-zero or return-to-zero pulse shape. This signal may be a polarization or multiplexed signal. This optical I/O modulator 104 may be driven by four individual data (In phase Quadrature Phase for X polarization and I Q for Y polarization). The baud rate of I or Q signals may preferably be f Gbaud/s.
[0009] An optical multiplexer 105 with a 3 dB bandwidth of −f GHz combines the signals transmitted from the optical I/O modulator 104 . This optical multiplexer 105 may be a regular WDM filter, a WDM coupler or array waveguide grating (AWG) or other optical filter to combine all of the channels. An optical amplifier 106 may be used to compensate any fiber loss. This optical amplifier 106 may be an Erbium doped fiber amplifier, Raman amplifier or other amplifier used to provide gain. The multiplexed signal may then be transmitted over a fiber 107 . The fiber 107 may be any transmission fiber. On the receiver side, coherent detection based on digital signal procession is used. The coherent detection technique employs the use of an optical local oscillator 108 , a 90 degree hybrid 109 , four balanced receivers, ADC chips and ASIC chips for digital signal procession. The frequency of the optical local oscillator 108 is preferably the same as the frequency of the subcarrier. The local oscillator 108 may be a distributed feedback laser (DFB) or an external cavity laser with a linewidth preferably smaller than a few MHz. The 90 degree hybrid 109 may be a regular optical 90 degree hybrid to demultiplex the I and Q signal. A digital coherent detection receiver 110 includes balanced or unbalanced photodiodes, high speed ADC and other electrical components such as ASIC, FEC, and the like.
[0010] FIG. 2 illustrates a schematic of digital signal procession (DSP) for a coherent receiver with post filter and maximum likelihood sequence estimation (MLSE). A compensation module 200 may correct an I/O imbalance of the received signal. A dispersion compensating unit 201 may compensate for chromatic dispersion. Sampling unit 202 resamples the signal. Subsequently, each bit is sampled twice. Through the use of adaptive equalizers 203 , a polarization demultiplexer generates polarization demultiplexed signals. An offset module 204 compensates for a frequency offset of the demultiplexed signals in order to improve the quality of communication. Phase module 205 phase compensates the demultiplexed signal. A filter 206 post filters the phase compensated signal. The filter 206 may be a 2 tap filter. MLSE, which may be two state, is applied to the filtered signals, finally a bit error rate is calculated.
[0011] It should be understood that the methods and devices of the present invention may be executed employing machines and apparatus including simple and complex computers. Moreover, the architecture and methods described above can be stored, in part or in full, on forms of machine-readable media. For example, the operations of the present invention could be stored on machine-readable media, such as magnetic disks or optical disks, which are accessible via a disk drive (or computer-readable medium drive). Alternatively, the logic to perform the operations as discussed above, could be implemented in additional computer and/or machine readable media, such as discrete hardware components as large-scale integrated circuits (LSI's), application-specific integrated circuits (ASIC's), firmware such as electrically erasable programmable read-only only memory (EEPROM's); and the like. Implementations of certain embodiments may further take the form of machine-implemented, including web-implemented, computer software.
[0012] While aspects of this invention have been shown and described, it will 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 in the spirit of the following claims.
|
Aspects of the present invention include apparatus and methods for transmitting and receiving signals in communication systems. A multicarrier generator generates a multicarrier signal. An optical demultiplexer separates the multicarrier signal into separate multicarrier signals. At least one QPSK modulator modulates signals from the separate multicarrier signals. An optical multiplexer combines the QPSK modulated signals into a multiplexed signal. The multiplexed signal is then transmitted.
| 7
|
This application is a division of application Ser. No. 838,295, filed Mar. 10, 1986, now U.S. Pat. No. 4,733,152.
BACKGROUND OF THE INVENTION
This invention relates to reciprocation pumps and control circuits for them.
In one class of reciprocating pump, a piston continuously reciprocates in a cylinder to directly force a liquid from the cylinder, alternately pulling liquid into the cylinder through an inlet port from a reservoir and pushing it from the cylinder through an outlet port to the destination of the liquid.
In some uses of this class of pump, the pumps are designed to reduce pulsation in the flow of fluid. One such use is liquid chromatography. It is desirable in liquid chromatography that liquid which is pumped through a chromatographic column flow at a constant flow rate through the column so that different molecular species in the effluent from the column are eluted at times that are reproducible from run to run. Pulses in which the liquid flows at unpredictable rates reduce this reproduciblity.
In one type of prior art pump of this class, the pressure at the outlet port of the pump is measured by a pressure sensor. A feedback signal from the pressure sensor controls the speed of the pump motor to cause the pump motor to react to changes in pressure in the chromatographic column and thus maintain a more constant rate of flow of the fluid. One pump of this type is described in U.S. Pat. No. 3,985,467, issued Oct. 12, 1976 to Peter Lefferson.
This type of pump has a disadvantage when used in liquid chromatography in that it maintains pressure constant against varying pressure loads but may cause the rate of flow of fluid through the chromatographic column to vary, even in applications where is is desirable to maintain the rate of flow of liquid constant.
In another type of prior art pump of this class, the piston is driven at a constant rate while expelling liquid from the pump into the chromatographic column, but when returning on a fill stroke to draw fluid into the pump from the reservoir, the motor is driven at an increased and substantially constant speed to draw the fluid into the pump more rapidly.
During the forward stroke of piston in this type of prior art pump, the piston moves at a higher than normal rate until the pressure in the pump cylinder equals the pressure that existed near the end of the liquid expelling forward stroke of the piston and just before the piston began a refill stroke. After the pressure in the cylinder reaches the pressure during constant flow rate pumping before the start of the refill stroke, the outlet valve is opened and the piston continues forward at a constant rate. This type of pump is described in U.S. Pat. No. 4,131,393 issued Dec. 26, 1978, to Haaken T. Magnussen Jr. and 4,180,375 issued Dec. 25, 1979 to Haaken T. Magnussen Jr.
This type of pump has several disadvantages such as for example: (1) the opening of the valve at the pressure of the last part of the previous cycle results in an increased time during which no liquid leaves the outlet port over that time needed to fill the cylinder; and (2) the constant speed of the motor during refill and pump up does not reduce the time before fluid leaves the pump as soon as it could.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a novel pump.
It is a further object of the invention to provide a novel method for pumping fluid in a manner that maintains a constant rate of flow of fluid through a chromatographic column spaced from the outlet of the pump.
It is a still further object of this invention to provide a pumping technique in which the speed of the motor is constant during a second portion of a pumping stroke until a refill portion of a cycle is initiated and then continuously increasing in speed during refill and until after a first portion of the pumping stroke controlled in time duration.
It is a still further object of this invention to drive a pump motor for a reciprocating pump at a constant rate during a first portion of a cycle with a feedback circuit and at an accelerating rate during a second portion controlled by a timer and an open loop control circuit.
It is a further object of the invention to maintain average rate of flow constant.
It is a still further object of this invention to provide a reciprocating pump for a chromatographic system in which the pump refill time is maintained as short as possible and liquid is pumped in such a manner as to prevent cavitation but increase the rate of flow of fluid temporarily to maintain as constant as possible from cycle to cycle the average amount of liquid pumped through the liquid chromatographic column.
It is a still further object of the invention to cause a smooth acceleration of pumping for a time after a refill stroke to reduce the danger of cavitation but maintain the flow rate at the column as constant as possible.
In accordance with the above and further objects of the invention, the speed of a motor which drives a direct displacement reciprocating pump is controlled by first and second related signals. These signals are related so that a high constant rate of pumping controlled by the first signal results in a long time of acceleration of the pumping action later under the control of the second signal to more quickly average the flow rate to the preset flow rate of the liquid after a refill portion of a pump cycle.
The first signal provides a linear feedback control on the pumping motion of a piston during a time period in which the rate of flow of liquid from the pump is equal to a present rate of flow and the piston moves at a preset velocity. The second signal is a nonlinear positive feedback signal which accelerates the motor linearly through an open loop to pull liquid from the liquid reservoir as fast as possible without cavitation and to provide liquid without cavitation to the outlet port of the pump at a rate to replace, in the conduit to the chromatographic column, the liquid necessary to bring the average rate of flow back to the preset value with little interruption to fill the cylinder. Thus, the piston is driven in a continuously varying rate except for a portion of a pump cycle.
A second feedback loop, within which the first and second signals operate, measures the flow rate from the pump and corrects the preset rate of flow current source to maintain the average flow rate over a pump cycle constant.
From the above description, it can be understood that the pump of this invention has several advantages such as: (1) the time during which no liquid is pumped through the outlet port is low; (2) it is relatively uncomplicated because the acceleration time of the motor is time limited rather than distance limited; (3) it is able to accommodate a wide range of flow rates without cavitation; (4) it maintains an accelerating velocity during a first part of each pumping stroke related to the required liquid to be replaced; and (5) it repeatedly monitors rate of flow and corrects the input signal outside of the feedback loop to aid in maintaining average flow constant.
SUMMARY OF THE DRAWINGS
The above noted and other features of the invention will be better understood from the following detailed description when considered with reference to the accompanying drawings in which:
FIG. 1 is a block diagram of a chromatographic system utilizing an embodiment of the invention;
FIG. 2 is a block diagram of a control system for a high pressure pump in the chromatographic system of FIG. 1 in accordance with an embodiment of the invention;
FIG. 3 is a block diagram of a motor circuit for a pump in accordance with the embodiment of FIG. 2;
FIG. 4 is a schematic circuit diagram of a portion of the motor control circuit of FIG. 3;
FIG. 5 is a schematic circuit diagram of another portion of the motor control circuit of FIG. 3;
FIG. 6 is a schematic circuit diagram of still another portion of the motor control circuit of FIG. 3;
FIG. 7 is a schematic circuit diagram of still another portion of the motor control circuit of FIG. 3;
FIG. 8 is a schematic circuit diagram of another portion of the motor control circuit of FIG. 3;
FIG. 9 is a block diagram of a portion of the circuit of FIG. 2;
FIG. 10 is a block circuit diagram of one portion of the block diagram of FIG. 9;
FIG. 11 is a schematic circuit diagram of a portion of the block diagram of FIG. 10;
FIG. 12 is a schematic circuit diagram of another portion of the block diagram of FIG. 10;
FIG. 13 is a schematic circuit diagram of a portion of the block diagram of FIG. 9;
FIG. 14 is a schematic circuit diagram of still another portion of the block diagram of FIG. 9;
FIG. 15 is a schematic circuit diagram of still another portion of the block diagram of FIG. 9;
FIG. 16 is a schematic circuit diagram of still another portion of the block diagram of FIG. 9;
FIG. 17 is a schematic circuit diagram of another portion of the embodiment of the motor control circuit of FIG. 2;
FIG. 18 is a block diagram of still another portion of the block diagram of FIG. 2;
FIG. 19 is a block diagram of another portion of the block diagram of FIG. 2;
FIG. 20 is a block diagram of a portion of the block diagram of FIG. 18;
FIG. 21 is a block diagram of another portion of the block diagram of FIG. 18;
FIG. 22 is a schematic circuit diagram of a portion of the block diagram of FIG. 20;
FIG. 23 is a schematic circuit diagram of a portion of the block diagram of FIG. 22.
FIG. 24 is a schematic circuit diagram of another portion of the block diagram of FIG. 22;
FIG. 25 is a schematic circuit diagram of still another portion of the block diagram of FIG. 20;
FIG. 26 is a block diagram of still another portion of the block diagram of FIG. 22;
FIG. 27 is a block diagram of still another portion of the block diagram of the motor control system of FIG. 2;
FIG. 28 is a schematic circuit diagram of a portion of the block diagram of FIG. 26;
FIG. 29 is a schematic circuit diagram of still another protion of the block diagram of FIG. 26;
FIG. 30 is a sectional view, partly schematic of a pump in accordance with an embodiment of the invention; and
FIG. 31 is a schematic circuit diagram of an average rate of flow circuit.
DETAILED DESCRIPTION
In FIG. 1, there is shown a block diagram of a chromatographic system 10, having a low pressure system 12, a high pressure pumping system 14, a high pressure pump control system 16, a chromatographic column, and injector system 18 and a detector and collector system 20. The high pressure pumping system 14 communicates with the low pressure system 12 to receive solvents therefrom and with the chromatographic column and injector 18 to supply the influent thereto for detection and at times collection by the detector and collector system 20.
To control the high pressure pumping system 14, the high pressure pump control system 16 is electrically connected to the low pressure system 12 from which it receives signals relating to flow rate of the influent to the chromatographic column and injector system 18 and is electrically connected to the high pressure pumping system 14 to maintain that flow rate as constant as possible.
The low pressure system 12, the chromatographic column and injector system 18 and the detector and collector system 20 are not part of this invention except insofar as they cooperate with the high pressure pumping system 14 and the high pressure pump control system 16 to provide a constant flow rate of solvents through the chromatographic column and injector system 18.
The low pressure system 12 includes a low pressure pumping and mixing system 24 and a general system controller 22. The general system controller 22 contains flow rate information and, in some configurations, gradient information as well as information for injecting samples into the chromatographis column or providing data acquisition and processing functions in conjunction with the detector and collector system 20. The general system controller 22 is not part of the invention except insofar as it provides signals to the high pressure pump control system 16 to control the flow rate from the high pressure pumping system 14.
In FIG. 2, there is shown a block diagram of the high pressure control system 16 having a motor circuit 30, a flow rate circuit 32, a first flow rate control system 34, a second flow rate control system 36 and an average flow rate control loop circuit 47. The first flow rate control system and the second flow rate control system each apply signals to the flow rate control circuit through conductors 62 and 64, one of them applying generally linear signals during at least a portion of each cycle of operation of the motor circuit and the other applying nonlinear signals through conductor 64.
The linear and nonlinear signals control a pulse-width-modulator within the flow rate circuit 32 which ultimately controls the speed of the motor circuit 30 to maintain the flow rate of the fluid through the chromatographic column and injector system 18 (FIG. 1) as nearly constant as possible. The linear and nonlinear signals are related, with the nonlinear signals being larger or smaller in relation to the linear signal and for this purpose the first flow rate control system and second flow rate control system are electrically connected through a conductor 556 in a manner to be described hereinafter. The average flow rate control loop circuit 47 periodically measures output liquid flow during each cycle of the pump and changes the signal on conductor 46 representing the preset flow rate to maintain an average flow rate equal to the preset flow rate.
To provide a substantially linear signal during at least a portion of the motor circuit 30, the first flow rate control system 34 includes a linear flow rate control circuit 38 and a first compensation circuit 40. The first compensation circuit 40 receives signals from the motor circuit 30 to provide certain correction signals to the linear flow rate control circuit 38 to which it is connected. The linear flow rate control circuit 38 receives signals from the system controller 22 (FIG. 1) on a conductor 46 indicating the desired rate of flow and supplies a resulting signals to the flow rate circuit 32 which includes corrections made in response to the motor circuit 30 and from the first compensation circuit 40.
To provide a signal to the flow rate control circuit 32 to accelerate the pump motor, the nonlinear flow rate control system 36 includes a nonlinear flow rate control circuit 42 and a second and positive feedback compensation circuit 44 (hereinafter second compensation circuit). The nonlinear flow rate control circuit 42 receives signals from the motor circuit 30 to which it is electrically connected and applies signals through an electrical connection to the flow rate circuit 32 as modified by signals from the second compensation circuit 44.
With this arrangement, the high pressure pump system 16 maintains the flow rate through the column relatively constant at the programmed rate to cause the time at which peaks are detected to be reproducible because of pulses of fluid of different rates occurring at different times in the column rather than constantly eluting the molecular species from the column. Generally, the high pressure pump control system 16 controls the pump motor through the motor circuit 30 in such a way as to maintain the average flow of fluid at the preset rate and minimize rapid fluctuations in flow rate such as might be caused by a refill stroke of a piston pump or the like.
In FIG. 3, there is shown a block diagram of the flow rate circuit 32 and the motor circuit 30. The flow rate control circuit 32: (1) receives a signal on conductor 62 during a portion of a pump cycle which is the output of a servo loop and has a substantially linear relationship with the desired pumping rate; and (2) a signal on conductor 64 which is a ramp nonlinearly corrected in slope to relate to the preset average flow rate. Both signals contain some corrections which are directed to establishing a rate of pumping which permits a single piston reciprocating pump to approach constant flow through a chromatographic column across a period of time.
The flow rate circuit 32 is electrically connected to the motor circuit 30 through a conductor 66 to apply to the motor circuit 30 periodic pulse-width-modulated signals in which the pulse width (duty cycle) is related to the speed at which the piston is intended to move to: (1) reduce flow rate pulsations in the chromatographic column by maintaining the average rate of flow of influent to the column is as constant as possible; and (2) change the piston speed to reduce the time that the pump is not forcing fluid through its outlet port. The speed of the piston is controlled to avoid cavitation or changes in the flow rate that are so sudden as to disrupt the rate of flow through the chromatographic column and injector system 18 (FIG. 1).
To provide a speed of piston movement for constant flow rate of the influent to the chromatographic column and injector system 18 (FIG. 1), the motor circuit 30 includes a motor 50, a brake circuit 52, a refill inception detector circuit 54, a tachometer disc and sensors system 58, and an overcurrent sensor circuit 60. The motor 50 is driven by power applied through the conductor 66 from the flow rate control circuit 32 and drives the piston of the pump (not shown in FIG. 3) through its outlet shaft 56.
To slow the pump, dynamic braking is under some circumstances applied to the motor through the brake circuit 52 in response to control signals on a conductor 70 indicating the time of application of the brake. The brake circuit 52 transmits signals through a conductor 72 to the first compensation circuit 40 (FIG. 2) which is used to adjust the motor speed at the end of a motor acceleration portion of a cycle to reduce drive power to the motor.
To aid in coordinating the pump motor control circuit within the second compensation circuit 44 (FIG. 2), the refill inception detector circuit 54 transmits a signal on conductor 76 for application to the first compensation circuit 40 (FIG. 2) at the end of a liquid delivery stroke to initiate a refill portion of a cycle. This signal aids in timing the start and termination of motor acceleration.
To generate signals indicating the volume of fluid pumped and motor speed, the tachometer disc and sensors system 58 generates signals for application through conductor 78 to the linear flow rate control circuit 38 (FIG. 2) and the average flow rate control loop circuit 47 (FIG. 2). The overcurrent sensor circuit 60 detects currents which exceed a preset value in the motor circuit, usually indicating binding or a bearing fault, so as to avoid damage to the pump.
In FIG. 4, there is shown a schematic circuit diagram of the flow rate circuit 32 having a comparator circuit shown generally at 80 and a driver circuit shown generally at 82, with the comparator circuit 80 receiving a ramp signal on conductor 64 from the second flow rate control system 36 (FIG. 2), a linear signal on conductor 62 from the first flow rate control circuit 34 (FIG. 2) and an overcurrent protection signal on conductor 84 from the second flow rate control system 36 (FIG. 2).
These signals result in an positive-going variable width 13 KHz (kilohertz) pulse train being applied by the comparator through a conductor to the drive circuit 82 inversely related to how steep the ramp circuit applied to conductor 64 is, and directly related to the amplitude of the signal applied to 62, which determines the duty factor of the pulse train.
The motor driver circuit 82, during the time duration it receives the pulse train from the comparator 80, applies a variable voltage across conductor 66A and 66B, resulting in power being applied to the motor 50 (FIG. 3) during a time controlled by the pulse-width-modulator 32 and consistent with the pulse train applied by the comparator 80.
To compare the ramp signal on conductor 64 with the servo input signal on conductor 62, the comparator circuit 80, is a LM 311 voltage comparator sold by National Semiconductor, 2900 Semiconductor Drive, Santa Clara, Calif. 25051, and described in its 1985 catalogue "Linear Integrated Circuits", having pin 1 electrically connected to the driver circuit 82, pin 2 electrically connected to conductor 62 through a 10K resistor 92 to receive the servo input signals, pin 3 electrically connected to conductor 64 to receive the ramp, a pin 4 electrically connected to a source 94 of a negative 12 volts and to the electrical common through a 1 uf (microfarad) capacitor 96, pin 6 electrically connected to conductor 84 to receive an overcurrent signal from the second flow rate control system 36 (FIG. 2) and pin 8 electrically connected to a source 98 of a positive 12 volts. An equivalent circuit would be a simple comparator having an inverter on its output connected to one input of a two input AND gate and conductor 84 connected to the other input.
The comparator 86 has its noninverting input terminal electrically connected to conductor 62 through the resistor 92 and its inverting input terminal electrically connected to conductor 64. A first rail is electrically connected to the source 94 of a minus 12 volts and to electrical common through the capacitor 96 and its other rail electrically connected to the source 98 of a positive 12 volts. The output of the comparator from pin 1 is electrically connected to the driver circuit 82 to apply a signal thereto corresponding to the time in which the ramp voltage applied on conductor 64 is less than the level on conductor 62.
The driver circuit 82, includes a MTP12N05 MOSFET transistor 102, a MR2400F diode 104 (all manufactured by Motorola Corporation), and a source 106 of a positive 32 volts. The gate of the transistor 102 is electrically connected: (1) to the output of the comparator 86 through a 33 ohm resistor 108; (2) to a source 112 of a negative 8 volts through a 820 ohm resistor 110; (3) to the overcurrent sensor circuit 60 (FIG. 3) through the reverse resistance of a 1N5245B Zener diode 114; and (4) to a source 98 of a positive 12 volts through the resistor 110.
The source of the transistor 102 is electrically connected to the overcurrent sensor circuit 60 (FIG. 3) through a conductor 118. To provide noise filtering for the comparator 86, the source 98 of a positive 12 volts is electrically connected to electrical common through two 1 uf capacitors 120 and 122 in parallel with each other and to the source 112 of a negative 8 volts through a 1 uf capacitor 116, with a source of negative volts 112 also being electrically connected to the gate through the resistor 110 to provide biasing directly to the gate. A 0.2 uf capacitor 174 is connected across conductors 66A and 66B to filter lower frequencies.
Conductor 118 is essentially grounded for power supply purposes and the drain is electrically connected through the forward resistance of the diode 104 to the source 106 of a positive 32 volts and to conductor 66A so that, the positive 32 volts is connected at all times to one end of the armature of the motor 50, (FIG. 3) conductor 66B on the other armature and being electrically connected through a current limiting inductor 124 to the anode of the diode 104 and the drain of the transistor 102. The capacitance across the motor is essentially 2 uf. The motor is a Pitman 13000 series DC motor and the inductor is substantially 200 uh (microhenries).
With this circuit arrangement, when the transistor 102 is conducting as a result of the positive pulse at its gate, current flows from the source 106 of a positive 6 volts through the motor, the inductor 124 and the transistor 102 to ground through conductor 118, and when the positive pulse is not applied, the current is maintained by inductor 124 through diode 104 and, the motor and back through the inductor unless the motor is operating to generate current for dissipation in the brake circuit 52 (FIG. 3) to be described hereinafter.
With this arrangement, when the linear feedback circuit indicates that the motor speed falls below its preset speed, the pulse width is increased linearly and when the nonlinear feedback circuit indicates the need for acceleration to equalize the flow, the width of the pulse is increased provide a correction of motor speed in a velocity feedback loop during a portion of a pump cycle prior to refill. The nonlinear feedback circuit provides an acceleration signal prior to the constant flow portion of the deliver for a longer time as the flow rate during the last portion of delivery increases and a shorter time as it decreases.
In FIG. 5, there is shown a schematic circuit diagram of the brake circuit 52 (FIG. 3) having an input logic circuit 130, a drive circuit 132, and a shunt circuit 134. The input logic circuit 130 receives a signal on conductor 70 from the second flow rate correction circuit 36 (FIG. 2) and causes the drive circuit 132 to form a conducting path in the shunt circuit 134 across the armature of the motor to provide dynamic braking. The input logic circuit 130 also applies output signals through conductor 72 to the second compensation circuit 44 (FIG. 2) and to conductor 62 to the flow rate control circuit 32 (FIG. 3).
To provide a signal causing dynamic braking, the input logic circuit 130 includes a NAND gate 136, input conductor 70 and output conductor 72 and 62. The NAND gate 136 has one of its inputs electrically connected to a source 138 of a positive 8 volts and its other input electrically connected to the input 70 through a 10K resistor 140 to receive signals from the second flow rate correction system 36 (FIG. 2) indicating braking action. The output of the NAND gate 136 is electrically connected to conductor 72 to provide a positive output signal when braking action is to occur and to conductor 62 through the 1N5060 diode 142 to turn off drive pulses from the flow rate control circuit 32.
To energize the dynamic brake, the drive circuit 132 includes first and second NPN transistors 150 and 152 and a diode 154. The anode of the diode 154 is electrically connected to the output of the NAND gate 136 and its cathode is electrically connected to the base of the transistor 150 through a 4.7K (kilohm) resistor 156 and to electrical common through a 4.7K resistor 158. The emitter of transistor 150 is electrically connected to the base of transistor 152 and to electrical common through a 470 ohm resistor 160 and the emitter of transister 152 is directly connected to electrical common. The collector of the transistors 150 and 152 are each electrically connected to the input to the shunt circuit 134 through two 39 ohm resistors 162 and 164 electrically connected in series. The transistors 150 and 152 are 2N3704 and D44C8 transistors manufactured by G.E. Corporation and described in the catalogue and the diode 154 is a type 1N914 diode.
To form a conducting path for current generated by the pump motor when it is being driven by inertia and thus to provide dynamic braking, the shunt circuit 134 includes a D45H8 PNP transistor 170, and a 1N5060 diode 172. The transistor 170 has its base electrically connected to the output of the drive circuit 132, its emitter electrically connected to its base through a 220 ohm pull-down resistor 173 and its collector electrically connected through the diode 172 to its emitter and to conductor 74B through a resistor 176.
The emitter of the transistor 170 is electrically connected to conductor 66A so that, when the motor operates as a generator for dynamic braking, a path is formed between conductors 66A and 66B through the motor and transistor 170 when transistor 170 is saturated and provides an open circuit when the motor is driven as a motor.
In FIG. 6, there is shown a schematic circuit diagram of the refill inception detection circuit 54 (FIG. 3), having an optical sensor 180, a rotatable flag 182 on the cam shaft, and a comparator 184. The flag 182 shown in fragmentary schematic form, rotates with the cam shaft on it in a location to be detected by the optical sensor 180, which transmits a positive going pulse in response to a signal indicating the start of the refill cycle to the noninverting input terminal of the comparator 184. The comparator 184 signals the second flow rate control system 36 (FIG. 2) indicating the start of the refill cycle in response to the detected signal.
For this purpose, the comparator 184 has its noninverting input terminal electrically connected to electrical common through a 2.2K resistor 186 and to the output of the optical sensor 180. The inverting input terminal of the comparator 184 is electrically connected to conductor 76B, to electrical common through a 100 ohm resistor 188 and to a source 112 of a negative 8 volts through a 1.5K resistor 190 so that a reference potential is established, above which a signal is provided through conductor 76A indicating a refill cycle. The comparator 184 has positive and negative 8 volt rails at 138 and 112.
The optical sensor 180 has a light emitting diode, with its anode electrically connected to electrical common and its cathode electrically connected to a source of negative 8 volts through a 1.5K resistor 192 and has a light sensitive transistor therein with its collector electrically connected to the noninverting input terminal of the comparator 184 and its NPN emitter junction electrically connected to the source 112 of a negative 8 volts.
In FIG. 7, there is shown a schematic circuit diagram of the overcurrent sensor circuit 60 (FIG. 3) having a current sensing network 202, a reference network 204 and a comparator circuit 206. The sensing network 202 senses the motor current and the reference network 204 provides part of the reference with both values being compared in the comparator circuit 206 to provide an output signal disabling the flow rate control circuit 32 (FIG. 3 and FIG. 4) when the motor current is too high indicating a jammed condition of the pump or the like.
To sense the current through the pump, the current sensing network 202 includes three 0.1 ohm resistors 210, 212, and 214 respectively connected in parallel between a conductor 216 and a conductor 218. Conductor 216 is electrically connected to conductor 118 to receive motor current and conductor 218 is electrically connected to the electrical common so that the current flow through the motor on conductor 118 causes a voltage drop in the sensing network 202, which voltage drop occurs between conductors 216 and 218.
To provide a reference potential, the reference network 204 is electrically connected: (1) through 86.6K resistor 240 to 4.7K resistor 234 and thence to the source of a positive 8 volts; (2) to conductors 216 and 218; and (3) to the comparator circuit 206 through conductors 220 and 222. Conductor 216 is electrically connected through a conductor 200 to the anode of the Zener diode 114 (FIG. 4) of the flow rate control circuit 32 (FIG. 2, 3, and 4) to receive current therethrough and to conductor 220 through a 1K resistor 224. Conductor 218 is electrically connected to conductor 222 through a 4.75K resistor 226 and to a source 112 of a negative 8 volts potential through a 309K resistor 228. With this circuit arrangement, conductor 222 is maintained at a potential above the electrical common by the sources of potential 138 and resistors 234 and 240.
To compare the potential on conductors 220 and 222 for the purpose of indicating an overcurrent, the comparator circuit 206 includes the comparator 230 which is manufactured and sold by National Semiconductor Corporation (2900 Semiconductor Drive, Santa Clara, Calif. 95051) type 311 having its inverting input terminal at pin 3 electrically connected to conductor 220 and its noninverting input terminal at pin 2 electrically connected to conductor 222 to provide a comparison of the voltages therein.
During an overcurrent, the output at pin 7 of the comparator goes from 8 to common potential. The removes positive potential from resistor 240 and negative potential from sources 112 through resistor 278 causes the comparator to latch up and disable the motor drive circuit.
At the end of the pulse cycle, a reset pulse on pin 6 at 296 resets the comparator from a clock in the second positive feedback and compensation circuit 44 to enable the comparator and drive circuit 32.
The output of the comparator 230 at pin 7 is electrically connected to: (1) the source 138 through the resitor 234; (2) a conductor 84 through 680 ohm resistor 239; (3) the reverse resistance of the 8.2 IN5237 volt Zener diode 237 and the foreward resistance of diode 238; and (4) input conductor 222 through a 86.6K resistor 240. The conductor 84 (FIG. 4) is electrically connected to the pulse width modulator 86 (FIG. 4) so that conductor 84 provides signals to disable the flow rate circuit 32 (FIGS. 2, 3 and 4) by de-energizing the comparator 86 upon a current overload condition.
In FIG. 8, there is shown a schematic circuit diagram of the tachometer disc and sensor system 58 (FIG. 3) having a first and a second optical sensor 250 and 252 respectively, rotatable disc 254 and first and second 270 ohm resistors 258 and 260 respectively. The first and second optical sensors sense indicia indicating the rotation of the pump on disc 254 which is mounted to the output shaft of the pump motor. The optical sensors 250 and 252 are located in quadrature with respect to the indicia so as to indicate the amount of rotation of the motor and its direction in a manner in the art.
With this arrangement, the optical sensors provide signals indicating the amount of rotation and direction of the motor by rotation of the disc in one direction as well as position of the piston in part of a delivery stroke by sensing indicia at equispaced distances along the disc 254. This type of circuit is described in U.S. copending application No. 713,328 to Robert W. Allington et al, assigned to the same assignee as this application and filed Mar. 18, 1985.
To sense indicia on disc 254 the first optical sensor 250 includes a light emitting diode having its anode electrically connected to the electrical common and its cathode electrcially connected to the source 112 of a negative 8 volts through the resistor 258. To provide electrical signals indicating the amount of electrical rotation of the disc 254, the first optical sensor 250 includes a light sensitive element separated from the light emitting diode by the disc 254 to have light blocked or transmitted to it as the disc 254 rotates.
The light sensitive element has its collector electrically connected to the linear flow rate control circuit 38 (FIG. 2) and nonlinear flow rate control circuit 42 (FIG. 2) and average flow rate control loop circuit 47 (FIG. 2) circuit 47 through a conductor 262 and has its emitter electrically connected to the source 112 of a negative 8 volts to provide electrical signals to a conductor 262 indicating the amount of rotation of the pump.
The second light sensor 252 has a light emitting diode in it with its anode electrically connected to the electrical common and its cathode electrically connected to the source 112 of a negative 8 volts through the 270 ohm resistor 260. It has a light sensitive element separated from the light emitting diode 252 by the rotatable disc 254 so as to sense indicia upon it.
The light sensitive element has its collector electrically connected to the linear and nonlinear flow rate control circuit 38 and 42 (FIG. 2) through a conductor 264 and average flow rate control loop circuit 47 (FIG. 2) and has its emitter electrically connected to the source 112 of a negative 8 volts so as to provide electrical signals to conductor 264 indicating the amount of rotation of the disc 254 with the signals on conductors 262 and 264 indicating the amount of rotation and the direction of rotation.
In FIG. 9, there is shown a block diagram of the nonlinear flow rate control circuit 42 (FIG. 2) having a quadrature detector 270, a frequency to voltage converter 272, a multivibrator circuit 274, an exponential amplifier circuit 276 and a ramp generator 278. The quadrature detector 270 is electrically connected to conductors 262 and 264 to receive signals from the tachometer disc and sensor system 58 (FIGS. 3 and 8) and apply a signal indicating the amount of rotation in one direction to a conductor 290/frequency to voltage converter 272 which generates a signal representing in amplitude the rate of rotation of the motor for application to a conductor 280.
Conductor 280 is electrically connected to the exponential amplifier circuit 276 and the output from the exponential amplifier circuit 276 and from the multivibrator circuit 274 are connected to the ramp generator 278 to generate a ramp which varies in slope in a manner related to the motor speed.
To receive correcting signals, the second compensation circuit 44 (FIG. 2) is connected to the ramp generator 278 through a conductor 282 and to select the flow rate operating range of the frequency to voltage converter control signal is applied to the frequency to voltage converter 272 from the linear flow rate control circuit 38 (FIG. 2) through a conductor 284 to select a flow rate range.
In FIG. 10, there is shown a block diagram of the quadrature detector 270 (FIG. 9) having a pulse output conductor 290, a direction circuit 292 and a tachometer sensor input circuit 294. The tachometer sensor input circuit 294 is electrically connected to conductors 262 and 264 to receive signals from the first and second optical sensors 250 and 252 (FIG. 8) respectively, which sensors generate pulses at the same frequency as the motor rotates but 90 degrees out of phase. The output of the tachometer sensor input circuit 294 applies both sets of pulses to the direction circuit 292 which selects oly those pulses which indicate a forward movement of the pump piston or plunger for application to the output at conductor 290. This circuit is explained in the aforementioned patent application.
The tachometer sensor input circuit 294 includes a first channel 296 and a second channel 298 with the first channel 296 being electrically connected to the first optical sensor 250 through conductor 262 to recieve signals therefrom and electrically connected to the direction circuit 292 through a conductor 300 and the second channel 298 being electrically connected to the second sensor 252 (FIG. 9) through the conductor 264 to receive signals therefrom and to the direction circuit 292 through a conductor 302 to supply signals thereto. The first channel 296 is identical to the first channel 298 except that they receive signals from different sources and supply to the direction circuit 292 through different conductors.
In FIG. 11, there is shown a schematic circuit diagram of the first channel 296 (FIG. 10) within the tachometer sensor input circuit 294 (FIG. 10) having a first operational amplifier 304 and a second operational amplifier 306. The amplifiers 304 and 306 are type LM353 amplifiers each having one rail connected to a source 138 of a positive 8 volts and the other rail electrically connected to a source 112 of a negative 8 volts.
To provide amplification and low pass noise filtering, amplifier 304 has its noninverting input terminal electrically connected to the electrical common and its inverting input terminal electrically connected to: (1) conductor 262 through a 470 ohm resistor 308 and to a source 138 of a positive 8 volts through the resistor 308, a 27K resistor 310 and a variable 50K resistor 312 so as to permit adjustment of the input to operating current of the light sensor connected to conductor 262. The output of amplifier 304 is electrically connected to: (1) its inverting input terminal through a 56K resistor 314 and 150 pf (picofarad) capacitor 316 electrically connected in parallel; and (2) to the noninverting input terminal of the amplifier 304 through a 47K resistor 318.
To provide Schmidt trigger action, amplifier 306 has its output electrically connected to: (1) conductor 300 through a 4.7K resistor 320, a source 138 of a positive 8 volts through the resistor 320 and the forward resistance of a 1N273 diode 322; (3) and the electrical common through the reverse resistance of a 1N273 diode 324; (4) to its noninverting input terminal through a 1.2M resistor 326 and to the electrical common through the resistor 326 and a 47K resistor 328.
In FIG. 12, there is shown a schematic circuit diagram of the direction circuit 292 (FIG. 10) having a divide-by-two circuit 330, an up-down counter circuit 332 and an input gating circuit 334. The input gating circuit 334 is electrically connected to conductors 300 and 302 to receive signals processed by channels 1 and 2 from the first and second sensors 250 and 252 respectively (FIG. 8) and has its output electrically connected to the up-down counter circuit 332 which caused by backward movement of counts pulses proportional to the motor, by counting backwards from 15 and requiring recounting of those pulses in the forward direction for application to the divide-by-two circuit 330 and eventually to output conductor 290 to the frequency to voltage converter 272 (FIG. 9).
The input gating circuit 334 includes four exclusive OR gates 336, 338, 340 and 342 and one NOR gate 344. Conductor 300 is electrically connected to one input of each of the exclusive OR gates 338 and and conductor 302 is electrically connected to another input of the two input exclusive OR gates 338 and 342 and to: (1) an input of the exclusive OR gate 342 through a 150K resistor 346; and (2) to the electrical common through the resistor 346 and a 120 pf capacitor 348. The output of exclusive OR gate 338 is electrically connected to: (1) one of the two inputs of the exclusive OR gate 336; (2) the input of the NOR gate 344 through a 27K resistor 350; and (3) the electrical common through the resistor 350 and a 120 pf capacitor 352.
The output of the exclusive OR gate 342 is electrically connected to one of the two inputs of the exclusive OR gate 340, the other input being electrically connected to a source 138 of a positive 8 volts. The output of the exclusive OR gate 336 is electrically connected to a source 138 of a positive 8 volts. The output of the exclusive OR gate 336 is electrically connected to the up-down counter circuit 332 through a conductor 354 and the output of the OR gate 340 is electrically connected to the up-down counter circuit 332 through a conductor 356 to provide signals corresponding to the first and second sensor thereto modified so that signals received from the first sensor before the second count up and signals received by the second sensor before the first sensor count down.
The up-down counter circuit 332 includes a type 4029 up-down counter 360 and a type 4002B NOR gate 362. Conductor 354 is electrically connected to pin 15 of the counter 360 to cause it to count up and conductor 356 is electrically connected to pin 10 of the counter 360 to cause it to count down and to one of the four inputs of the NOR gate 362, the output of which is electrically connected to pin 5 to inhibit counting upon receiving a signal on conductor 356 passing through the NOR gate 362.
Pins 2, 14 and 11 of the counter 360 are each electrically connected to: (1) a different one of the other three inputs of the NOR gate 362; and (2) a different one of the 10K resistor 364, 22K resistor 366 and 39K resistor 368. The other end of the resistors 364, 366 and 368 are each electrically connected to: (1) pin 6 of the counter 360 through an 82K resistor 370; and (2) the electrical common through a 1K resistor 372. Pins 8 and 4 of the counter 360 are grounded and pins 16, 13, 12, 9 and 3 are electrically connected to the source 138 of a positive 8 volts to determine the output voltage of the counter. Pins 1 and 7 are electrically connected to conductors 374 and 376 to provide output positive 8 volt pulses as the counter counts in binary notation upwardly in response only to signals caused by rotation of the motor in the direction which enables the piston to force fluid from the cylinder of the pump. The counter counts downwardly in response to reverse rotation but is inhibited from counting past zero.
To divide the binary signals applied on conductors 374 and 376 in two, the divide-by-two circuit 330 includes a type 4013B divider 374 having pins 3 and 11 electrically connected to conductor 376 and pin 13: (1) electrically connected to conductor 374 and to pin 10 through a 2.7K resistor 380; and (2) to the electrical common through resistor 380 and a 0.01 uf capacitor 382. Pins 9 and 14 of the divider 378 are each electrically connected to the source 138 of a positive 8 volts, pin 1 is electrically connected to conductor 290 to provide a frequency output representing the rate of flow of effluent from the pump, pins 2 and 5 are electrically connected together and pins 4, 6, 8 and 7 are each electrically connected to the electrical common.
In FIG. 13, there is shown a schematic circuit diagram of a frequency to voltage converter 272 (FIG. 9) having an analog switch 390, an LM2907 frequency to voltage converter 392 and a gain adjustment circuit 394.
The frequency to voltage converter may be any suitable type, many of which are known in the art but in the preferred embodiment it is an integrated circuit sold by National Semiconductor under the disignation LM2907. Pin 1 of that unit is electrically connected to conductor 290 to receive pulses from the tachometer disc and sensor system 58 (FIG. 3 and 8) through a 22K resistor 396. This circuit is part of a tachometer that produces an output voltage porportional to motor speed.
The conductor 290 is also electrically connected to the electrical common through the resistor 396 and a 22K resistor 398 and to the system controller 22 (FIG. 1) through a 10K resistor 402 and a conductor 400 where it may be used by the system to indicate the progress of the chromatographic run. The frequency to voltage converter 392 has pin 11 electrically connected: (1) through a source 138 of a positive 8 volts and a 47K resistor 404 for biasing; and (2) through a 0.47 uf capacitor 406 and a 15K resistor 408 to the electrical common in parallel to short out noise. Pins 7 and 12 are electrically connected to a source 112 of a negative 8 volts and to the electrical common through a 1 uf capacitor 410, pins 8 and 9 electrically connected to a source 138 of a positive 8 volts and to the electrical common through a 1 uf capacitor 412.
To accommodate changes in pumping speed, the frequency to voltage converter 392 has pin 2 electrically connected to: (1) the electrical common through an 820 pf capacitor 414; and (2) one lead of 4016 analog switch 390 through an 820 pf capacitor 416. The gate of the analog switch 390 is connected to conductor 418 to receive a low range signal and the other level is electrically connected to the electrical common.
The switch 390 doubles the gain of the frequency to voltage converter by doubling capacitance by switching capacitor 416 in parallel with 414 to provide low range operation at a high scale with an additional multiplier to be described hereinafter upon receiving a signal on conductor 418.
To control the gain of the voltage conversion provided by frequency to voltage converter 392, the gain control circuit 394 includes a first 5K potentiometer 424 and a second 5K potentiometer 426 with the potentiometer 426 being connected at one end to a source 138 of a positive 8 volts and at the other end to a source 112 of a negative 8 volts, its variable tap being electrically connected through a 10 megaohm resistor 427 to: (1) pin 10 through a switch which may be opened or closed; (2) and pin 3 of the frequency to voltage converter 392; (3) pin 5 through a 0.022 uf capacitor 428 and a 0.33 uf capacitor 430; and 4 and to the tap of the potentiometer 424 through a 30.9K resistor 432.
The potentiometer 424 is electrically connected at one end to a conductor 280 and to pin 5 of the frequency to voltage converter 392 and at its other end to the electrical common through a 10K resistor 436 and directly to pin 5 of the frequency to voltage converter and to pin 5 of the voltage to frequency converter through the capacitor 430. Conductor 280 applies the voltage corresponding to the rate of flow of fluid to the exponential amplifier circuit 276 (FIG. 9) through conductor 280 and to the first compensation circuit 40 (FIG. 2). Conductor 280 is electrically connected to the source 94 of a negative 12 volts through a 604 ohm resistor 440.
With this arrangement, the amplitude of the voltage output may be adjusted by potentiometer 424 and 426 to provide a voltage which varies in relation to the rate of flow of fluid as measured by the tachometer. This voltage is applied to the first compensation circuit 40 (FIG. 2) for application to the linear flow rate control circuit 38 (FIG. 2) and to the exponential amplifier circuit 276 (FIG. 9) through conductor 280 to control the nonlinear flow control circuit 42 (FIG. 2).
In FIG. 14, there is shown a schematic circuit diagram of the multivibrator circuit 274 (FIG. 9) having a conventional astable multibrator 450 which may be of any conventional designation but in the preferred embodiment is a National Semiconductor 55 multivibrator connected as shown to provide a suitable frequency during a portion of the time normally required for a full piston stroke of the pump. The function of the multivibrator circuit is to reset the overload circuit and the ramp generator.
To provide the proper frequency, the miltivibrator circuit 274 includes: (1) 3 capacitors 452, 454 and 456 having values of 1 uf, 0.01 uf and 2200 pf respectively; (2) 2 resistors 458 and 460 having values of 680 ohms and 39.2 ohms respectively; and (3) a 10K potentiometer 462 with pins 4 and 6 of the multivibrator 450 being electrically connected to one end of the potentiometer 462, pin 7 being electrically connected to: (1) to the other end of the potentiometer 462 through the resistor 460; (2) pins 6 and 2 of the multivibrator 450 through the resistor 458; and (3) to the electrical common through the capacitor 456. The electrical common is also electrically connected to pin 1, to pin 5 through the capacitor 454 and to pins 4 and 8 through the capacitor 452.
To reset the ramp generator 278 (FIGS. 9 and 16) and to the flow rate control circuit 32 (FIGS. 2, 3 and 4) the output, of the multivibrator 450 is electrically connected to conductor 470 to apply a positive pulse thereto. To provide a signal to the ramp circuit to initiate a ramp, the multivibrator 274 includes a source 112 of a negative 8 volts electrically connected to conductor 470 through a 3.9K resistor 472 and a 1.82K resistor 474 with output conductor 476 being electrically connected to resistor 472 and 474 to change from a negative to a positive value upon receiving a signal from the multivibrator 450. conductor 476 is electrically connected to the ramp generator 278 (FIGS. 9 and 16) to reset it as described hereinafter in connection with FIG. 16. (FIG. 9).
To provide a turn-off signal on conductor 84 to the flow rate circuit 32 (FIGS. 2, 3 and 4) conductor 84 (FIGS. 4 and 14) is electrically connected to conductor 470 through a 680 ohm resistor 478, the reverse resistance of CR106 zener diode 480 and the forward resistance of a 1N914 diode 482.
To reset the overcurrent sensor 60, (FIGS. 3 and 7) conductor 296 to the overcurrent sensor 60 is electrically connected through a 680 ohm resistor 484 and through the forward resistance of a 1N914 diode 486 to conductor 470 to apply a positive potential thereto, permitting the flow rate circuit 32 (FIGS. 2, 3 and 4) to operate.
In FIG. 15, there is shown a schematic circuit diagram of the exponential amplifier circuit 276 (FIG. 9) having a first PNP 2N3702 transistor 490, a second PNP 2N4061 transistor 492, an adjustment circuit 496 and a bias circuit 494. The transistor 490 has a lower input impedance than transistor 492 and conducts approximately ten times the current through transistor 492. Thus, transistor 492 follows the potential on conductor 280, and provides an exponential drop between the emitter and base of transistor 492. The two transistors cancel their temperature coefficients. The first transistor 490 receives an input signal from the frequency to voltage converter 272 (FIGS. 9 and 13) on conductor 280 indicating the speed of pumping and varies the emitter bias of the transistor 492 to cause an exponential amplification of the signal from the frequency to voltage converter 272 for application through a conductor to the ramp generator circuit 278 (FIG. 9).
To provide emitter biasing to the first and second transistors 490 and 492, the emitters of each of these transistors is electrically connected to a source 98 of a positive 12 volts through a 1.18K resistor 502 and to a second such source through the 1.18K resistor 502 and a 33 ohm resistor 500.
To vary the emitter potential of the second transistor 490 in a manner related to the input amplitude on conductor 280 from the frequency to voltage converter 272 (FIGS. 9 and 13) so as to provide an exponential transfer function, the base of the transistor 490 is electrically connected to: (1) the electrical common through a 47.5 ohm resistor 508; (2) to input conductor 280 through a 1.40K resistor 504; and (3) to a source 106 of a positive 32 volts through a 45.3K resistor 506. The collector of the transistor 490 is electrically connected to a source 112 of a negative 8 volts so that it will draw current through the emitter biasing circuit from the source 98 of a positive 12 volts and through the resistor 502 in proportion to the input signal on conductor 280 and thus cause a drop in the positive potential on the emitter of the transistor 492 as the current increases.
To provide a further adjustment on a sawtooth waveform to be controlled by the transistors 490 and 492, the adjustment circuit 496 includes a 1.18K resistor resistor 510, a 100K resistor 512 and a 5K potentiometer 514. To establish biasing, one end of the potentiometer 514 is electrically connected to a source 138 of a positive 8 volts and the other end is electrically connected to a source 112 of a negative 8 volts, with the movable tap being electrically connected to the base of the transistor 492 through a 100K resistor 512. The base of the transistor 492 is also electrically connected to the electrical common through a 1.18K resistor 510 to provide biasing. The collector of the transistor 492 is connected to conductor 520 to provide an exponentially decreasing amplification of the signal received on conductor 280.
To provide a continuous bias on conductor 520, the bias circuit 494 includes a 150K resistor 516 and a 500K potentiometer 518. The resistor 516 and potentiometer 518 are electrically connected between a source 98 of a positive 12 volts and the conductor 520 to permit adjustment of the voltage drop for application of a current to the ramp generator 278.
In FIG. 16, there is shown a schematic circuit diagram of the ramp generator 278 (FIG. 9). To form a ramp which varies in slope in a manner related to the output from the exponential amplifier 276 (FIGS. 9 and 15) for application to the flow rate circuit 32 (FIGS. 2 and 4) the ramp generator circuit 278 includes a type TL011C current mirror 530 made and sold by Texas Instruments, a 2N3710 NPN transistor 532, a 2N4403 PNP transistor 534, and a 910 pf capacitor 536. The current mirror 530 has its input electrically connected to conductor 520 to receive the output of the exponential amplifier circuit 276 (FIGS. 9 and 15) and its output electrically connected to conductor 64 to apply current which decreases as the motor speed increases from a high output impedance source with a gain of 1 to draw current from capacitor 536 across to generate a negative going ramp from the capacitor.
The common of the current mirror 530 is electrically connected to the collector of diode connector transistor 532 through which it conducts current. The emitter of the transister 532 is electrically connected to a source 112 of a negative 8 volts to control the bias on current mirror 530. The 2.7K resistor 538 keeps the voltage at its collector of the transistor 532 relatively constant at about 7.3 volts regardless of the operation of the current mirror 530.
To form a ramp from the output of the current mirror 530, conductor 64 is electrically connected to its output and to one plate of the capacitor 536, the other plate of which is electrically connected to the emitter of transistor 534. With this arrangement, the current flowing from the output of the current mirror 530 charges capacitor 536 to form a ramp potential on conductor 64.
To reset capacitor 536, the transistor 534 has its collector electrically connected to conductor 64 and its base electrically connected to the multivibrator circuit 274 (FIGS. 9 and 14) through conductor 476 so that when the multivibrator provides a negative pulse at the end of a ramp, transistor 534 becomes conducting to discharge capacitor 536. When transistor 534 becomes nonconducting at the end of the negative pulse at its input, the capacitor 536 receives a high impedance between one plate in conductor 64 and low impedance on the other to be in condition to charge and form a ramp potential on conductor 64 as current flows through the current mirror 530.
The current mirror 530 may be any conventional circuit which results in a complementary current flow from its input. In the preferred embodiment, this is a commercial integrated circuit designated TL011c and sold by Texas Instrument.
In FIG. 17, there is shown a schematic circuit diagram of the linear flow rate control circuit 38 (FIG. 2) having a reference voltage to current converter 540, a summing node 542, a switch 544, and a servoamplifier circuit 546. The reference voltage to current converter 540 receives a signal indicating the desired constant flow rate of the influent to the chromatographic column on conductor 46 and converts it to a current for application to the summing node 542 where it is summed with a feedback signal. Upon being gated by the gate 544, this signal is applied to the main servoamplifier circuit 546 where it is subtracted from certain other correction signals for application through conductor 62 to the flow rate circuit 32 (FIGS. 2, 3 and 4).
To provide a feedback signal during the delivery portion of a pumping stroke, the summing node 542 receives: (1) a current set to represent the desired flow rate from resistor and low pass filter 540; and (2) a current from conductor 548 (FIG. 19) fed back from the motor circuit 30 (FIG. 2) representing the effluent as corrected by the first compensation circuit 40 (FIG. 2) in a manner to be described hereinafter.
This current is gated by the analog gate 544 under the control of a signal on conductor 550 to the inverting terminal of the servoamplifier 546 where it is summed with a signal from the first compensation circuit 40 (FIG. 2) through a conductor 598.
The main servoamplifier 546 receives a signal from the second compensation circuit 44 (FIG. 2) through a conductor 554 and the difference between the two signals is applied to conductor 62. Conductor 62 at different times receives compensation circuits on conductors 556 to provide servo gain and certain compensations such as for compressibility of the fluids, logic signals on conductor 558, a refill gain correction signal on conductor 560, and a gain from the braking circuit on conductor 562.
To process the set point voltage on conductor 46 and apply to summing node 542, the reference voltage to current converter 540 includes a 10K resistor 570, a 0.1 uf capacitor 572, and a 187K resistor 574. The resistor 570 is electrically connected at one end to conductor 46 and at its other end to the electrical common through the capacitor 572 and the summing node 542 through the resistor 574.
The switch 544 is a type 4016 integrated circuit switch sold by the aforementioned National Semiconductor although any suitable electronically operated switch may be used. The switch 544 is electrically connected to be controlled by the first compensation circuit 40 (FIG. 2).
To compare the signal on conductor 548 fed back from the motor tachometer, with the signal on conductor 46 indicating the desirable flow rate, the servoamplifier circuit 546 includes an LM 353 differential amplifier 580 sold by National Semiconductor, four resistors 582, 584, 586 ad 590, a 22 pf capacitor 592, and a 1N914 diode 594. The resistors are a 470 ohm resistor 582, a 10K resistor 584, a 47K resistor 586 and a 220 ohm resistor 590. The resistor 582 is electrically connected at one end to the output of the switch 544 and at its other end to: (1) the inverting input terminal of the amplifier 580 to supply a signal thereto representing the flow rate error signal; and (2) conductor 598 electrically connected to the first compensation circuit 40 (FIG. 2); and (3) to the output of the differential amplifier 580 through the capacitor 592.
The output of the amplifier 580 is electrically connected to conductor 62 through the resistor 590 and the amplifier has a source 138 of a positive 8 volts connected as one rail at pin 8 and a source 112 of a negative 8 volts connected as a second rail at pin 4. The noninverting input terminal of the amplifier is electrically connected to: (1) the electrical common through the resistor 586; (2) conductor 554 to receive the feedback pumping rate signal; and (3) a conductor 596 through the forward resistance of the diode 594 and the resistor 584 for placing the pump in the stop mode. Conductor 596 receives a signal from a start circuit under the control of the system controller 22 (FIG. 1).
In FIG. 18, there is shown a block diagram of the first compensation circuit 40 (FIG. 2) as it is electrically connected to the linear flow rate control circuit 38 (FIGS. 2 and 17). The first compensation circuit 40 includes a summing node compensation circuit 600 and a servoamplifier compensation circuit 602 each electrically connected to the linear flow rate control circuit 38 at different locations, with the summing node compensation circuit 600 being electrically connected to the summing node 542 (FIG. 17) and the servoamplifier compensation circuit 602 being electrically connected to the servoamplifier inverting input at 598 and at its output as shown at 556, 558, 560 and 562 (FIG. 17).
With this arrangement, the speed of the motor is corrected by the range of fluid that is flowing, the measured average flow of the influent into the chromatographic column and for certain factors such as the braking gain, refill gain, servo gain and liquid compensation or for braking values at the input to the servoamplifier.
In FIG. 19, there is shown a schematic circuit diagram of the summing node compensation circuit 600 (FIG. 18) having a range selection circuit 608 and coupling circuit shown generally at 604. The range selection circuit 608 may energize either a high or low voltage levels current to be applied to the coupling circuit 604 which receives the variable amplitude voltage from the frequency to voltage converter 272 (FIGS. 9 and 13) on conductor 280 and converts it to a current applied through conductor 548 to the summing node. The magnitude of the current depends on whether a high or low range is selected. While a range selection circuit 608 is shown connected to conductor 630, in the preferred embodiment, a signal from the microprocessor is used to energize the transister 610 and open switch 640. In this specification, a high signal is applied to terminals 628 to select a one-tenth scale set point and corresponding feedback signals and terminals 626 or 418 from a low range in which the signals are subject to less attenuation by a factor of 10.
To provide a larger or smaller current depending on the selection of a high or low range, the range selection circuit 608 includes a 2N3704 NPN transistor 610, a 2N3704 NPN transistor 612 and seven resistors which are respectively a 2.2K resistor 614, a 2.2K resistor 616, a 230 ohm resistor 618, a 2.43K resistor 620, 1K resistor 622, and a 22K resistor 624.
To provide a low range current, the transistor 610 has its emitter electrically connected to a source 112 of a negative 8 volts, its base electrically connected to: (1) a source 94 of a negative 12 volts through the resistor 622; and (3) a source 138 of a positive 8 volts through resistors 618 and 620 in series and has its collector electrically connected to: (1) a contact 626 within the range selection circuit 608 for a low range current; (2) the base of transistor 612 through resistor 624; and (3) a source 138 of a positive 8 volts through the resistor 616.
The emitter of the transistor 612 is electrically connected to a source 112 of a negative 8 volts and its collector is electrically connected to a source 138 of a positive 8 volts through the resistor 614. The range selection circuit 608 has a movable contact which connects a source of positive potential to either the low range switch 626 or the high range switch 628, the low range switch placing a voltage on conductor 630 and the high range switch placing a voltage on conductor 632.
The conductor 630 is electrically connected through conductor 418 to the frequency to voltage converter 272 (FIGS. 9 and 13) to ground the capacitor 410 (FIG. 13), thus increasing the amplitude of the output potential.
To convert potential to current for application to the summing node 542 (FIG. 17) through conductor 548, the coupling circuit 604 includes an analog switch 640, a 0.047 uf capacitor 642, three resistors and a 5K potentiometer 652. The three resistors are an 11.5K resistor 646, a 49.9K resistor 648 and a 4.7K resistor 650. Conductor 280 from the output of the voltage to frequency converter 272 (FIGS. 9 and 13) is electrically connected to: (1) the input of the switch 640 through the potentiometer 652 and the resistor 648; and (2) electrical common through the resistor 650 and the capacitor 642. The gate of switch 640 is electrically connected to conductors 630 and 418 and its output is electrically connected to electrical common through the resistor 448 and the capacitor 642.
In FIG. 20, there is shown a block diagram of the servoamplifier compensation circuit 602 (FIG. 18), having a braking gain circuit 660, a refill gain circuit 662, a servo gain and compensation circuit 664, a delivery logic circuit 666, and an acceleration time generator circuit 668. Each of these circuits generates signals relating to the timing of the acceleration of the pump motor and applies the signal to the linear flow rate control circuit 38 (FIGS. 2 and 17) through a plurality of analog switches. The analog switches are 670, 672 and 674.
For this purpose, the acceleration time generator circuit 668 applies signals to the delivery logic circuit 666 and to conductor 550 through one conductor and to the switch 672 through another conductor. The switch 670 is controlled by a signal on conductor 72 from the brake circuit 52 (FIGS. 3 and 5) to apply a brake gain through conductor 560 and a servo gain from the servo gain and compensation circuit 664 through conductor 558 by opening switch 674. The refill gain is applied from the refill gain circuit 662 upon being opened by a signal from the acceleration time generator circuit 668 indicating a refill cycle.
In FIG. 21, there is shown a schematic circuit diagram of the braking gain circuit 660, the refill gain circuit 662, and the servo gain and compensation circuit 664 and their associated switches 670, 672 and 674 (FIG. 20). The braking gain circuit 660 is controlled by switch 670, the refill gain circuit 662 is controlled by switch 672 and the servo gain and compensation circuit 664 is controlled by the switch 674 to which they are connected to apply currents through conductor 598 to the flow rate control circuit 38 (FIGS. 2 and 17) to change the speed of the motor in accordance with corrections required for braking, refill and servo gain and compensation.
The braking gain circuit 660 includes a 4.7M resistor 680 electrically connected at one end to the output switch 670 and at its other end to conductor 598 to attenuate the signal on conductor 598 during a braking cycle. Switch 670 has its gate input electrically connected to conductor 72 from the brake circuit 52 (FIG. 3) and its input electrically connected to the conductor 558. The analog switch controls the gain and applies an attenuated voltage of the servo amplifier. The level of the set point signal on conductor 46 is level shifted by the 7.5K resistor 677, the negative source 112 and the 2.05K resistor 675 to be applied to conductor 816 when switch 673 is opened.
The refill gain circuit 662 includes a 68K resistor 682 and a 1.2M (megohm) resistor 684. The resistor 682 is electrically connected to the electrical common at one end and connected to the one lead of the switch 672 and the resistor 682 is electrically connected at one end to conductor 598 to apply a signal to the linear flow rate control circuit 38. Switch 672 has its gate electrically connected to conductor 560 to the delivery logic circuit 666 (FIG. 20) and the second drain electrically connected through conductor 686 to the second compensation circuit 44 (FIG. 2).
To control servo gain and thus to provide servo stability, the servo gain and compensation circuit 664 includes an analog switch 688, two 3.3M resistors 690 and 692, a 180K resistor 694, a 0.22 uf capacitor 696 and a 0.047 uf capacitor 698. One lead of the switch 688 is electrically connected through the resistor 690 and the capacitor 696 in series to conductor 598 to apply a compensation signal thereto. The other lead of the switch 688 is electrically connected to: (1) the capacitor 696 through resistor 694; (2) one lead of the switch 694; (3) conductor 598 through the resistor 692 and the capacitor 698 in series.
To control the servo gain and compensation circuit, the switch 674 has its gate electrically connected to the delivery logic circuit 666 (FIG. 20) through conductor 700 (FIG. 20). With this arrangement, signals from the delivery logic circuit 666 are applied to the gate of switch 674 to close this switch and carry signals from resistors 692 and 694 and switch 688 providing the required compensations.
The refill gain circuit 662 (FIG. 20) upon receiving a signal on conductor 566 from the acceleration time generator circuit 668 indicating a refill cycle provides a feedback path for the servo amplifier through a resistive network including resistors 682, 684 and 685 to conductor 598 and the servo gain and compensation circuit 664 closes an additional feedback path for the servo amplifier through a resistance network including a signal applied to switch 688 on conductor 702.
In FIG. 22, there is shown a block diagram of the acceleration timer generator circuit 668 (FIG. 20) having an acceleration timer 710 and an acceleration timer output circuit 712. The acceleration timer 710 is electrically connected to conductor 76 to receive a refill inception signal, conductor 418 to receive a signal indicating the compressibility of the fluid being pumped and a signal on conductor 46 indicating the set flow rate.
The acceleration timer 710 processes these signals and applies a signal to the acceleration timer output circuit 712 and two conductors 550 and and 556 to speed up the motor at the end of fluid delivery at an accelerating rate to make up for fluid flow that will be lost during a time period before delivery commences again.
The acceleration timer 710 receives a signal indicating the start of the refill cycle and causes a time limit on motor acceleration while there is no flow so that the cylinder is filled across the period of time controlled by the timer. The motor may also be caused to accelerate in a forward stroke in a manner controlled by the acceleration timer 710 if the forward stroke starts during this time period. The time is increased as the flow rate increases.
In FIG. 23, there is shown a schematic circuit diagram of the acceleration timer 710 having a monostable multivibrator 714, a 2N4403 PNP transistor 716 and an analog switch 718. The multivibrator 714 is type 555 sold by National Semiconductor Corporation identified above but any monostable multivibrator may be used provided it is designed to have satisfactory parameters in a manner known in the art.
To provide an output signal to conductor 724 related to the motor acceleration, the acceleration timer 710 has a time duration circuit 720, a connection to lead 418 which carries a signal indicating the compressiblity of the fluid being pumped and an output conductor 724, all of which are electrically connected to the multivibrator 714 so that the amplitude adjustment circuit 720 provides correction amplitude for high or low range, calibration and compression of liquids.
To trigger the monostable multivibrator 714, conductor 76A from the output of the comparator 184 (FIG. 6) drives conductor 724 high at inception of the refill stroke and goes low at the end of the signal and a short time later. It is differentiated by capacitor 762 to trigger the multivibrator to high and maintaining lead 724 high until the timer drops low under the control of capacitor 150 and current through transistor 716 to remove potential from conductor 724.
To permit adjustment of the signal on conductor 744 electrically connected to the collector of the transistor 716, the emitter of the transistor is electrically connected to a source 138 of a positive 8 volts through a 16.5K resistor 746 and a 10K potentiometer 748. The transistor 716 is a type 2N4403 and the adjustment of the potentiometer 748 adjusts the current applied to conductor 744 through its collector so as to permit adjustment of the acceleration time of the motor.
Conductor 744 is electrically connected to pins 6 and 7 and to the source 112 of a negative 8 volts through a 1 uf timing ramp capacitor 150, the source 112 being electrically connected to pin 1 and pins 4 and 8 being electrically connected to the source 138 of a positive 8 volts, whereby the time duration of the output pulse width from the multivibrator 714 is adjusted. Pin 5 of the multivibrator 714 is electrically connected to electrical common through a 0.01 uf capacitor 752 and pin 3 is electrically connected to conductor 724 through the forward resistance of a diode 1N914 754 to apply the output to conductor 724. The multivibrator 714 is triggered on by the tailing edge of a signal applied through conductors 76A and 76B from the refill initiator.
To trigger the multivibrator 714, the trigger circuit 722 includes a 1N914 diode 760, a 0.22 uf capacitor 762, a 1N273 diode 764, a 47K resistor 766 and a 3.74K resistor 768. Conductor 76B is electrically connected to conductor 76 through the resistor 768. Conductor 76B is electrically connected to conductor 76 through the resistor 768 and to pin 2 of the multivibrator 714 through the capacitor 762. Pin 2 is also electrically connected to the source 138 of a positive 8 volts through the resistor 766 and the forward resistance of the diode 764. Conductor 76A is electrically connected to conductor 724 through the forward resistance of diode 760 and to the cathode of the diode 754 so that, a pulse differentiated by capacitor 762 and resistor 47K triggers the multivibrator 714 to apply a potential to conductor 724.
In FIG. 24, there is shown a schematic circuit diagram of the acceleration timer output circuit 712 (FIG. 22) which receives a signal on conductor 724 to establish acceleration across a predetermined period of time and supplies signals to conductors 686 to close switch 672 (FIG. 21) and apply compensation from the refill gain circuit 662 (FIGS. 20 and 21) and conductor 550 to open switch 544 (FIG. 17) to disconnect potential from the summing node 542 (FIG. 17) to the servoamplifier 580 (FIG. 17).
To generate a signal for conductor 556, the output circuit includes a first LM 311 comparator 770 having its inverting input terminal electrically connected to conductor 724 and its noninverting input terminal electrically connected to: (1) electrical common through a 2.43K resistor 772; and 2 to a source 112 of a negative 8 volts through a 4.7K resistor 774. The comparator 770 has one rail electrically connected to a source 138 of a positive 8 volts and the other rail electrically connected to a source 112 of a negative 8 volts. Its inverted output terminal is electrically connected to conductor 556 and to a source 112 of a negative 8 volts through a 10K resistor 776.
To apply a signal to switch 544 (FIG. 17), the acceleration timer output circuit 712 (FIG. 22) includes a 2N3704 NPN transistor 780 having its base electrically connected to: (1) conductor 724 through a 15K resistor 782; and (2) to a source 112 of a negative 8 volts through a 2.2K resistor 784. The emitter of the transistor 780 is electrically connected to the source 112 of a negative 8 volts and to a source 138 of a positive 8 volts through a 1 uf capacitor 786. The source 138 of a positive 8 volts is electrically connected to the collector of the transistor 780 through a 4.7K resistor 788 and the collector of the transistor 780 is electrically connected to conductor 550 through a 22K resistor 790. Conductor 550 is connected to electrical common through a 0.1 uf capacitor 792.
In FIG. 25, there is shown a schematic circuit diagram of the delivery logic circuit 666 (FIG. 20) having three NAND gates 800, 802 and 804, respectively, and a differential amplifier 806. The differential amplifier 806 has its noninverting input terminal electrically connected to conductor 556 to receive the output from the main servoamplifier 546 (FIG. 17) through a 10K resistor 810 and a 68K resistor 812 in series. The inverting input terminal of the differential amplifier 806 is electrically connected to: (1) conductor 816 to receive a level shifted set point signal during braking; and (2) the electrical common through a 47K resistor 818 and through a 0.1 uf capacitor 820 in parallel to slow the motor when it is near its constant speed point.
The noninverting input terminal of the differential amplifier 806 is electrically connected to the electrical common through a 220 pf capacitor 822 and through the resistor 812 and a 0.1 uf capacitor 824. With this arrangement, the differential amplifier 806 transmits a negative going signal to one input of the two-input NAND gate 804 during braking. The other input of the NAND gate 804 and conductor 700 are electrically connected to the output of a flip-flop comprising NAND gate 802, one input of the NAND gate 802 being electrically connected to conductor 550 and its other input electrically connected to the output of NAND gate 800.
Conductor 550 goes to a low potential at the start of refill, setting the flip-flop composed of NAND gates 800 and 802. The output of NAND gate 802 is electrically connected to one input of the NAND gate 800 and the other input is electrically connected to: (1) a source 138 of a positive 8 volts through a 4.7K resistor 830 and the forward resistance of a 1N914 diode 832; (2) the source 138 of a positive 8 volts through the resistor 830 and a 220K resistor 834; and (3) the output of differential amplifier 806 through the resistor 830, a 0.001 uf capacitor 838 and a 10K resistor 840 in series in the order names. At the end of the braking period, the servo amplifier output voltage on lead 556 drops below the level shifted setpoint voltage on lead 816. This produces a negative transition at the output of differential amplifier 806 which resets flip-flop 800 and 802 through resistor 840, capacitor 838 and resistor 830. The output of the differential amplifier 806 is electrically connected to one of the two inputs of the NAND gate 804 so as to provide a low output signal for braking only when the flop-flop including NAND gates 800 and 802 is set and the output of differential amplifier 806 is high.
In FIG. 26, there is shown a block diagram of the second compensation circuit 44 having a refill acceleration compensation circut 850, a sample and hold amplifier circuit 852 and a servo voltage multiplier and offset circuit 854. The refill acceleration compensation circuit 850 receives signals on conductor 46 indicating the flow rate and on conductor 418 from the compensation circuit and applies a signal to the ramp generator 278 (FIG. 9 and 16) through conductor 282 when a switch 856 is closed by a signal on conductor 700.
To apply a speed-up signal to the servo amplifier, conductor 700 is electrically connected to gate 858 to open this gate and apply the servo gain and compensation to the servo voltage multiplier and offset circuit 854. Upon receiving a signal indicating fluid delivery on conductor 862 from the delivery logic circuit 666 (FIG. 20), the switch 864 is closed to store the servo feedback signal from the output of the servo amplifier in the sample and hold amplifier circuit 852. The sample and hold amplifier circuit 852 is connected to the serve voltage multiplier and offset circuit 854 to be corrected and to apply the signal through gate 858 to the input 554 of the servoamplifier for acceleration.
In FIG. 27, there is shown a schematic circuit diagram of the refill acceleration compensation circuit 850 having a first analog switch 852, a second analog switch 854 and a 2N3704 NPN transistor 857. The transistor 857 applies a signal through switch 864 to conductor 282 to correct for the acceleration compensation with a compressibility correction being applied to its base. To apply an acceleration offset to the transistor 857 conductor 46 carrying the set point signal is electrically connected to: (1) the base of transistor 857 through a 10K resistor 868; (2) to the analog switch 854 through the resistor 868; (3) to a source 94 of a negative 12 volts through a 1K potentiometer gate 70, a 500 ohm resistor 872 and a 1K resistor 874 in series in the order named.
With this arrangement, the potentiometer gate 870 may be adjusted to provide different base current to the transistor 857. The emitter of the transistor 856 is electrically connected to a source of a negative 8 volts 112 and its collector is electrically connected to the source of the switch 864 through a 46.4K resistor 880 to provide a signal to the output conductor 282 upon receiving a signal on conductor 700. To provide compressibility compensation, conductor 418 is electrically connected to the switch 864 through a 1.8M resistor 882.
To provide a signal to conductor 520 to modify the rate of acceleration which commences at the start of refill when a low range signal is received on conductor 626 by the switches 852 and 854, conductor 46 is electrically connected to the source of the one level of switch 852 through: (1) the resistor 858 and a 24.9K resistor 884; (2) through the resistor 868, a 2.7K resistor 886 and the resistor 884. Conductor 46 is connected to the electrical common through the resistor 868 and a 649 ohm resistor 888.
In FIG. 28, there is shown a schematic of the sample and hold amplifier circuit 852 having a switch 890, a storage capacitor 892 and an operational amplifier 894. The switch 890 is electrically connected to the output of the servoamplifier through conductor 556 and to conductor 282 to receive a signal during the delivery portion of the pumping cycle. The switch 890 has one lead electrically connected to: (1) one plate of the 0.22 uf storage and noise filtering capacitor 892 through a 680K resistor 896 and a 3.3M resistor 898; (2) to the noninverting terminal of the amplifier 894 through the resistors 896 and 898; (3) to the electrical common through a 1 uf storage and noise filtering capacitor 900; and (4) to a source 138 of a positive 8 volts through the 22M resistor 902. The capacitor 892 is a 0.22 uf capacitor having one of its plates connected to the output of the switch 890 and its other connected to electrical ground. The capacitors 892 and 900 store a voltage representing the drive signal to the pump motor during the delivery portion of the pumping.
The output of the operational amplifier 894 is electrically connected to its inverting input terminal and to a conductor 904 from the servo voltage multiplier and offset circuit 854 (FIG. 26). With this circuit arrangement, a value of potential equivalent to the drive signal to the motor stored on capacitors 892 and 900 and applied with an offset to conductor 904 to the servo voltage multiplier and offset circuit 854.
In FIG. 29, there is shown a schematic circuit diagram of the servo voltage multiplier and offset circuit 854 (FIG. 26) having an operational amplifier 910, a first potentiometer 912, an analog switch 914, and a second potentiometer 916. The potentiometer 916 is electrically connected at one end to a source 138 of a positive 8 volts and at the other end to a source 112 of a negative 8 volts to permit selection of a potential to be applied to the source of switch 914 and the potentiometer 912 is electrically connected at one end to conductor 904 of the sample and hold amplifier circuit 852 (FIGS. 26 and 28) through a 1K resistor 918.
The potentiometer 916 is a 10K potentiometer and the potentiomenter 912 is a 2K potentiometer. The other end of the potentiometer 912 is electrically connected through a 6.19K resistor 920 and a 100K resistor 922 to the inverting input terminal of the operational amplifier 910. The inverting input terminal of the operational amplifier 910 is also electrically connected to conductor 558 through a 100K resistor 924 to receive a signal from the output of the servoamplifier.
The output of the amplifier 910 is electrically connected through a 220 ohm resistor 926 to one side of the resistor 922 and through a 22 pf capacitor 928 to the other end of the resistor 922 and to the inverting input terminal of the amplifier 910. The noninverting input of the amplifier 910 is electrically connected to the electrical common so that the input signal from the output of the main servoamplifier on conductor 558 is applied to the inverting input terminal of the amplifier 910. The output of the amplifier 910 is applied to one end of the servo voltage multiplier where its magnitude is adjusted by the servo offset and servo voltage multiplier potentiometers and by the signal on conductor 904 for application through the switch 914 and conductor 554 to the input of the servoamplifier, thereby providing a feedback circuit which incorporates a sample and hold circuit and certain corrections.
When switch 914 closes and connects the wiper of potentiometer 912 to conductor 554, a negative signal from the sample and hold circuit at 904 is applied through the main servoamplifier 580 (FIG. 17) and inverted in amplifier 910. The signal is transmitted from conductor 904 on the output of the amplifier 894 (FIG. 28) in the sample and hold amplifier circuit 852 (FIGS. 26 and 28), through the potentiometer 912 and conductor 554 to the noninverting input of servoamplifier 580 (FIG. 17) and to the inverting input of operational amplifier 910. The amplifier 910 includes equal input and feedback resistors 922 and 924 establishing a potential at 927 on the output of the inverter 910 connecting resistors 920, 922 and 926 which is inverted but equal to the potential at 558.
The servoamplifier 580 (FIG. 17) is a high gain amplifier and causes the potential at 554 to be close to zero. Because amplifier 910 is a part of a negative 1 gain inverter, point 927 is the inverted value of the output of the servoamplifier at 558. Since the potential at the wiper of potentiometer 912 is not far from zero volts, being not far from the potential at 554, the potential at 927 is a multiple of the potential at 904 established by the voltage divider including the resistance from the wiper to the point 927 and from the wiper to point 904. The voltage at 927 is a multiple of the sample and hold voltage which is equivalent to the motor drive signal during delivery and the output signal at 558 is the inverted value of the potential at 927 to represent a multiple of the motor drive signal during delivery.
During acceleration, 686 goes high to close 914 connecting it to potentiometer 916. The offset on 916 is set to cause the servoamplifier to go negative when switch 914 closes. Voltages on 554 to servoamplifier, when switch 914 is closed, reaches a balance depending on potentiometer setting 912. With the arrangement, the servoamplifier generates a signal to cause acceleration of the motor until terminated by the acceleration time generator circuit, causing the total volume of fluid per stroke to tend to equalize and thus reduce pulsations of current through the chromatographic column. The acceleration is related to the signal on conductor 558 reflecting the sample and hold voltage stored during delivery.
In FIG. 30, there is shown a schematic sectional view of a pump 14 (FIG. 1) having a cam 950, a cam follower 952, and a pump head 954. The cam 950 is mounted to the output shaft of the motor 50 (FIG. 3) for rotation thereby. The cam follower 952 is mounted to move in the direction of the pump head 954 and the direction of the output shaft as the cam rotates to provide a reciprocating motion for a piston within the pump head 954.
The pump head 954 includes an outlet port 956 and an inlet port 958, closed by pressure-activated valves so that when the piston is moved inwardly in response to the cam follower 952, fluid is drawn into the cylinder 960, the outlet port 956 being closed and the inlet port 958 being open. Similarly, when the piston is moved forwardly, fluid is forced from the outlet port 956 and fluid is blocked from entering or leaving the inlet port 958 by check valves therein. The high pressure pump itself and the electric motor are not part of the invention themselves except that the rotatable masses thereof are sufficient to provide a flywheel effect to the pump itself. This and other flywheel implements reduce the effect of friction and increases repeatability. Bearings are selected for low friction.
In FIG. 31, there is shown a schematic circuit diagram of a circuit 1000 for presetting a liquid flow rate from the pump to adjsut the amplitude of the current on conductor 46 having a keyboard 1002, a clock source 1004, an updating circuit 1006, and a current source 1003. The current 46, of course, may be set by any analog circuit including a manual potentiometer in a manner known in the art.
In the preferred embodiment, it is set by a software program utilizing an 8031 microcomputer of the type manufactured by Intel, containing 128 bytes of RAM, a serial port and two counter/timers. An EPROM in the unit contains instruction codes for controlling the pump. The software program for monitoring the current 46 to maintain a constant average flow rate as follows:
__________________________________________________________________________MCS-S1 MACRO ASSEMBLER HPLC RECIP PUMP, 11.059 CRYSTAL AND SERIALINSTALLEDL00 OBJ LINE SOURCE__________________________________________________________________________03B9 22 763 RET ;TO MISS ONE IN TIMING ALSO 764 ; 765 ; CALCULATIONS FOR THE SECONDARY ADJUSTMENTS BASED ON EACH RATE 766 ; JUMPED TO BY INTERRUPT 767 ; BASEC CONTROL EQUATION IS: 768 ; 769 ; DAC --ADJUST1=(DAC --OLD*833.3*TIME)/(PULSES*FL OW --BIN) 770 ; DAC --OLD = DAC --ADJUST1 OF LAST READING 771 ; 772 ; WHERE SOME ADDED CONVERSION FACTORS ARE NEEDED 773 ; AND PULSES 100 OR 300 AND TIME IS MEASURE, BUT NOT 774 ; ACTUALLY STORED IN A REGISTER 775 ; ADDITIONALLY, THE VALUES ARE LIMITED TO A ADJUSTMENT 776 ; OF 2% AT .5 ML LINEARLY INCREASING TO 25% AT .01 ML 777 ; 778 ;03EA C0D0 779 CALC: PUSH PSW ;PUSH RS0 AND RS1 WITH PSW03EC D2D3 780 SETB RSO03EE D2D4 781 SETB RS103FO 902001 782 MOV DPTR, #CO --1 ;LOAD IN TIMER VALUE03F3 E0 783 MOVX A,@DPTR03F4 FD 784 MOV R5,A03F5 E0 785 MOVX A,@DPTR03F6 FE 786 MOV R6,A03F7 7F00 787 MOV R7,#00H03F9 900306 788 MOV DPTR #NUMBER --OF --TIMES03FC E0 789 MOVX A,@DPTR03FD 04 790 INC A03FE F0 791 MOVX @DPTR,A ;PUT NUMBER BACK03FF 203805 792 JB A100 --PULSES,CHK --150402 B40507 793 CONE A,#05H,KEEP --COUNTING0405 8014 794 SJMP RESET --COUNTER0407 B40F02 795 CHK --15; CJNE A,#0FH,KEEP --COUNTING040A 800F 796 SJMP RESET --COUNTER040C 203806 797 KEEP --COUNTING: JB A100 --PULSES,LOAD --ONLY --100040F 71E0 798 ACALL LOAD --OTHER --COUNTSA0411 71C3 799 ACALL LOADEROF3000413 800E 800 SJMP KEEP --COUNT0415 71E0 801 LOAD --ONLY -- 100: ACALL LOAD --OTHER --COUNTSA0417 71CD 802 ACALL LOADEROF1000419 8008 803 SJMP KEEP --COUNT041B 7400 804 RESET --COUNTER: MOV A,#00H041D F0 805 MOVX @DPTR,A041E 121770 806 LCALL INIT --ADJUST ;LOCATED RIGHT AFTER KRUN0421 A1BE 807 AJMP CLEAR --OUT ;GET OUT OF HERE0423 7AFF 808 KEEP --COUNT: MOV R2,#0FFH ;LOAD IN 65535 (FFFF)0425 7BFF 809 MOV R3, #0FFH0427 7C00 810 MOV R4,#00H0429 B1D4 811 ACALL BINSUB ;SUBT 65535-COUNT --VALUE042B AA20 812 MOV R2,20H042D AB21 813 MOV R3,21H ;MULT BY 2560042F 7C00 814 MOV R4,#00H0431 7D00 815 MOV R5,#00H0433 7EOA 816 MOV R6,#0AH0435 7F00 817 MOV R7,#00H03A4 C24F 708 TO --MAIN: CLR START --UP ;IF MADE IT THROUGH, THEN IS STARTED UP03A6 0201CB 709 LJMP MAIN 710 ; 711 ; 712 ; THE FOLLOWING SUBROUTINES (GUASI --INT,NO --PRESS --UPDA,LOADEROFXXX, AND 713 ; CALC ALL BELONG TO THE THE FLOW RATE ALORITHM, QUASI --NT IS USED WHEN THE 714 ; INTERRUPTS HAVE BEEN DISABLED AND AFTER RENABLING, THE INTERRUPT BIT FOR 715 ; EXTERNAL IS SET. IT PULLS A "FAKE" INTERRUPT TO MAINTAIN THE ALGO. 716 ; ALSO, THE SUBROUTINES ADJUST --REF, TAKE --CARE --HIGH, AND TAKE --CARE LOW 717 ; ARE USED IN THE ALGORITHM AT DIFFERENT TIMES 718 ;03A9 209605 719 QUASI --INT: JB P1.6,CALL --CALC103AC D23C 720 SETB GATED ;GATE OFF PRESSURE03AE D23A 721 SETB GATED1 ;MESSAGE TO OTHER LOOPS TO03BO 22 722 RET ;START INITIAL ALGORITHM MODE03B1 61EA 723 CALL --CALC1: AJMP CALC ;RETURN IS IN CALC 724 ; 725 ; 726 ; REAL INTERRUPTS FROM EXTERNAL JUMP TO THIS SPOT 727 ;03B3 209606 728 NO --PRESS -- JB P1.6,CALL --CALC UPDA:03B6 D23C 729 SBTB GATED ;SET TO GATE OFF PRESSURE03B8 D23A 730 SETB GATE1 ;USED IN MAIN, RAPID, AND AGAIN03BA 8002 731 SJMP SKIDOO03BC 71EA 732 CALL --CALC: ACALL CALC ;NOT A REFILL PULSE BUT A TIMER PULSE03B5 D083 733 SKIDO0: FOP DPH03C0 D082 734 FOP DFL03C2 32 735 RETI 736 ; 737 ; THESE ROUTINES LOAD THE TACH COUNTER (CO --2) 738 ; 73903C3 902002 740 LOADEROF300: MOV DPTR,#CO --203C6 742B 741 MOV A,#2BH ;LOAD 299 SINCE FIRST PULSE LOADS IN 742 ;THE COUNT VALUE AND SO IS MISSED03C6 F0 743 MOVX @DPTR,A ;03C9 7401 744 MOV A,#01H ;03C8 F0 745 MOVX @DPTR,A03CO 22 746 RET03CD 902002 747 LOADEROF100: MOV DPTR,# CO --203D0 7463 748 MOV A,#063H ;LOAD IN 99 FOR SAME REASON AS 30003D2 F0 749 MOVX @DPTR,A03D3 7400 750 MOV A,#00H03D5 F0 751 MOVX @DPTR,A03D6 22 752 RET03D7 902000 753 LOAD --other -- MOV DPTR,#CO --C COUNTS:03D8 74BA 754 MOV A,#OEAH ;LOAD DO --C WITH 17,69803BC F0 755 MOVX @DPTR,A ;TIMERS LINKED TO 32 BITS03DD 7445 756 MOV A,#45H03DF F0 757 MOVX @DPTR,A03EO 902001 758 LOAD --OTHER -- MOV DPTR,#CO --1 COUNTSA:03E3 74FD 759 MOV A,#OFDH ;SO CO --1 COUNTS AT,01SEC03E3 F0 760 MOVX @DPTR,A ;DOWN FROM 6553303E6 74FF 761 MOV A,#OFFH ;65533 SINCE FIRST PULSE LOADS03E8 F0 762 MOVX @DPTR,A ;VALUE AND IS MISSED AND SEEMS0437 B1E8 818 ACALL BINMUL0439 AA23 819 MOV R2,23H043B AB24 820 MOV R3,24H043D AC25 821 MOV R4,25H043F 203816 822 JB A100 --PULSES,ONLY --1000442 7D46 823 MOV R5,#46H ;ADD 1282=502H (RNDING IN NEXT)0444 7E05 824 MOV R6,#05H ;12/2/85 ADD 1350=546H0446 7F00 825 MOV R7,#00H0448 B1C1 826 ACALL BINADD044A AA20 827 MOV R2,20H044C AB21 828 MOV R3,21H ;***12/2/85 CNG REF TO 833.3***044E AC22 829 MOV R4,22H0450 7D8C 830 MOV R5,#06CH ;DIVBY 2563=A034=(300*7500/878)0452 7E0A 831 MOV R6,#0AH ;WHERE 7500 IS 2000UL REF WORD0454 7F00 832 MOV R7,#00H ;*12/2/85 (300*7500/833.3)=27000456 8014 833 SJMP CALL --DIVIDER ;2700=A8CH0458 7DC2 834 ONLY --100: MOV R5,#0C2H ;ADD 427 FOR ROUNDING (854/2)045A 7B01 835 MOV R6,#01H ;427=1ABH045C 7F00 836 MOV R7,#00H ;**12/2/85 450=1C2H=(900/2)045E B1C1 837 ACALL BINADD0460 AA20 838 MOV R2,20H0462 AB21 839 MOV R3,21H0464 AC22 840 MOV R4,22H0466 7D84 841 MOV R5,#084H0468 7E03 842 MOV R6,#03H ;DIVBY 854=356H=(100*7500/878)046C 7F00 843 MOV R7,#00H ;**12/2/85 900=384H=(100*7500/833. 3)046D D1AD 844 CALL --DIVIDER: ACALL BINDIV046E AA20 845 MOV R2,20H ;GET RESULT0470 AB21 846 MOV R3,21H0472 AC22 847 MOV R4,22H0474 205206 848 JB CALIBRATED,DIVOTHER0477 AD46 849 MOV R5,FLOW --BIN ;MULTIPLY BY FLOWRATE BINARY FORM (0 TO 187 5 BINARY FOR 0 TO 500 UL/MIN)0479 AE47 850 MOV R6,FLOW --BIN+1047B 8004 851 SJMP DIV --NORM047D AD5F 852 DIVOTHER: MOV R5,FLOW --BIN --CAL ;IF CALIBRATED, USE THIS #047F AE60 853 MOV R6,FLOW --BIN --CAL+10481 7F00 854 DIV --NORM: MOV R7,#00H0483 B1E8 855 ACALL BINMUL0485 AA23 856 MOV R2,23H ;ADD 50 FOR DIVISION ROUNDING0487 AB24 857 MOV R3,24H0459 AC25 858 MOV R4,25H048B 7D32 859 MOV R5,# 50048D 7B00 860 MOV R6,#00048P 7F00 861 MOV R7,#000491 B1C1 862 ACALL BINADD0493 AA20 863 MOV R2,20H ;DIVIDE BY 1000495 AB21 864 MOV R3,21H0497 AC22 865 MOV R4,22H0499 7D64 866 MOV R5,#064H049B 7E00 867 MOV R6,#00H049D 7F00 868 MOV R7,#00H049F D1AD 869 ACALL BINDIV04A1 AA20 870 MOV R2,20H04A3 AB21 871 MOV R3,21H04A5 AC22 872 MOV R4,22H04A7 AD59 873 MOV R5,DAC --ADJUST104A9 AE5A 874 MOV R6,DAC --ADJUST1+104AB 7F00 875 MOV R7,#00H04AD B1E8 876 ACALL BINMUL ;MULTIPLY OLD BY CURRENT#04AF 7F00 877 MOV R7,#00H04B1 AA23 878 MOV R2,23H04B3 AB24 879 MOV R3,24H04B5 AC25 880 MOV R4,25H04B7 7D00 881 MOV R5,#00H04B9 7E05 882 MOV R6,#05H04BB 7F00 883 MOV R7,#00H04BD B1C1 884 ACALL BINADD ;ADD 1280 FOR ROUNDING04BF AA20 885 MOV R2,20H ;DIVIDE BY 2560 BY MOVING OVER04C1 AB21 886 MOV R3,21H ;ONE BYTE WHEN STORING04C3 AC22 887 MOV R4,22H04C5 7D00 888 MOV R5,#00H04C7 7E0A 889 MOV R6,#0AH04C9 7F00 890 MOV R7,#00H04CB D1AD 891 ACALL BINDIV04CD AA20 892 MOV R2,20H04CF AB21 893 MOV R3,21H04D1 AC22 894 MOV R4,22H04D3 900300 895 MOV DPTR,#DAC --OLD04D6 E559 896 MOV A,DAC --ADJUST104D8 F0 897 MOVX @DPTR,A04D9 A3 898 INC DPTR04DA E55A 899 MOV A,DAC --ADJUST1+104DC F0 900 MOVX @DPTR,A04DD AD59 901 MOV R5,DAC --ADJUST104DF AE5A 902 MOV R6,DAC --ADJUST1+104E1 8A59 903 MOV DAC --ADJUST1,R2 ;MOV NEW IN DAC --ADJUST04E3 8B5A 904 MOV DAC --ADJUST1+1,R304E5 B1D4 905 ACALL BINSUB ;SUBT NEW FROM OLD04E7 4069 906 JC BEELOW ;CARRY THEN ADJUST IS BELOW REF04E9 7A75 907 MOV R2,#75H ;USE 102+885/FLOW --BIN AS LIMIT04EB 7B03 908 MOV R3,#03H04ED 7C00 909 MOV R4,#0004EF AD46 910 MOV R5,FLOW --BIN04F1 AE47 911 MOV R6,FLOW --BIN+104F3 7F00 912 MOV R7,#0004F5 1206AD 913 LCALL BINDIV04F8 AA20 914 MOV R2,20H04FA AB21 915 MOV R3,21H04FC AC22 916 MOV R4,22H04FE 7D66 917 MOV R5,#1020500 7E00 918 MOV R6,#000502 7F00 919 MOV R7,#000504 1205C1 920 LCALL BINADD0507 AD20 921 MOV R5,20H0509 AE21 922 MOV R6,21H050B AF22 923 MOV R7,23H050D 900300 924 MOV DPTR,#DAC --OLD0510 E0 925 MOVX A,@DPTR ;LOAD OLD NUMBER TO MAKE 2% LIM0511 FA 926 MOV R2,A0512 A3 927 INC DPTR0513 E0 928 MOVX A,@DPTR0514 FB 929 MOV R3,A 00H0515 7C00 930 MOV R4,#00H0517 1205E8 931 LCALL BINMUL051A AA23 932 MOV R2,23H ;DIVIDE BY 100051C AB24 933 MOV R3,24H ;ADD 50 FIRST FOR ROUNDING051E AC25 934 MOV R4,25H0520 7D32 935 MOV R5,#500522 7E00 936 MOV R6,#00H0524 7F00 937 MOV R7,#00H0526 B1C1 938 ACALL BINADD0528 AA20 939 MOV R2,20H052A AB21 940 MOV R3,21H052C AC22 941 MOV R4,22H052E 7D64 942 MOV R5,#1000530 7E00 943 MOV R6,#000532 7F00 944 MOV R7,#000534 D1AD 945 ACALL BINDIV0536 A820 946 MOV R0,20H ;STORE IN TWO PLACES0538 A921 947 MOV R1,21H053A AA20 948 MOV R2,20H053C AB21 949 MOV R3,21H053B AC22 950 MOV R4,22H0540 AD59 951 MOV R5,DAC --ADJUST10542 AE5A 952 MOV R6,DAC --ADJUST1+10544 7F00 953 MOV R7,#00H0546 B1D4 954 ACALL BINSUB ;SUBSTRACT NEW FROM 2+% VALUE0548 4002 955 JC TIMES --102 ;IF CARRY THEN USE 2+% VALUE054A 806A 956 SJMP DACCY054C 8859 957 TIMES --102: MOV DAC --ADJUST1,R0054B 895A 958 MOV DAC --ADJUST1+1,R1 ;LOAD IN 2+% VAL0550 8064 959 SJMP DACCY0552 7A75 960 BEELOW: MOV R2,#75H0554 7B03 961 MOV R3,#03H0556 7C00 962 MOV R4,#00H0556 AD46 963 MOV R5,FLOW --BIN055A AE47 964 MOV R6,FLOW --BIN+1055C 7F00 965 MOV R7,#00H055E 1206AD 966 LCALL BINDIV0561 AD20 967 MOV R5,20H0563 AE21 968 MOV R6,21H0565 AF22 969 MOV R7,22H0567 7A62 970 MOV R2,#980569 7B00 971 MOV R3,#00H056B 7C00 972 MOV R4,#00H056D 1205D4 973 LCALL BINSUB0570 AD20 974 MOV R5,20H ;MULT BY 98-885/FLOW --BIN0572 AB21 975 MOV R6,21H ;WILL DIVIDE BY 100 TO GET A0574 7F00 976 MOV R7,#00H ;2+PERCENT LIMIT TO CHECK WITH0576 900300 977 MOV DPTR,#DAC --OLD0579 E0 978 MOVX A,@DPTR057A FA 979 MOV R2,A057B A3 980 INC DPTR057C B0 981 MOVX A,@DPTR 1750 ADJUSTER: ;THIS SUBROUTINE PREPARES THE TIMER (8253) 1751 ;FOR THE NEXT PART OF THE CONTROL ALGORYTHM 1752 17530B38 7A40 1754 MOV R2,#40H ;WAIT 40,000 CYCLES BEFORE CHECK0B3A 7B9C 1755 MOV R3,#90H ;EQUIVALENT TO .08 SEC0B3C DAFE 1756 ZEROSA: DJNZ R2,ZEROSA0B3E DBFC 1757 DJNZ R3,ZEROSA0B40 30B311 1758 JNB R3,3,NOADJUST ;IF STILL GATED, DISREGARD0B43 C23A 1759 CLR GATED1 ;GATE INTERRUPT HAS BEEN HANDELED0B45 20640C 1760 JB PREP --HEAD,NOADJUST ;NOADJUSTMENTS FOR PREP0B48 307D09 1761 JNB MICROL,NOADJUST ;OR FOR HIGH FLOWS0B4B E531 1762 MOV A,FLOW --RATE+10B4D B40502 1763 CJNE A,#05H,CHK --FURTHER ;ADJUSTS UP TO 499 UL/MIN0B50 8002 1764 SJMP NOADJUST0B52 4001 1765 CHK --FURTHER JC OK0B54 22 1766 NOADJUST: RET0B55 E531 1767 OK: MOV A,FLOW --RATE+1 ;READJUST FOR NEXT UPDATES0B57 B40103 1768 CJNE A,#01H,IS --LOWER ;IS IT LESS THAN 100UL0B5A 020B5F 1769 JMP NO --SET0B5D 4004 1770 IS --LOWER: JC SET --IT --HI ;IF IS, USE 100 PULSES0B5F C238 1771 NO --SET: CLR A100 --PULSES0B61 8010 1772 SJMP LOAD --3000B63 D238 1773 SET --IT --HI: SETB A100 --PULSES0B65 1203D7 1774 LCALL LOAD -- OTHER --COUNTS0B68 1203CD 1775 LCALL LOADEROF1000B6B 900306 1776 MOV DPTR,#NUMBER --OF --TIMES0B6E 7400 1777 MOV A,#00H ;CLEAR THIS0B70 F0 1778 MOVX @DPTR,A0B71 800C 1779 SJMP SET --CLOCK --COUNT0B73 1203D7 1780 LOAD --300: LCALL LOAD --OTHER --COUNTS0B76 1203C3 1781 LCALL LOADEROF3000B79 900306 1782 MOV DPTR,#NUMBER --OF --TIMES0B7C 7400 1783 MOV A,#00H ;0B7E F0 1784 MOVX @DPTR,A0B7F D296 1785 SET --CLOCK --COUNT: SETB P1.60B81 22 1786 RET 1787 ; 1788 ; 1789 ; 1790 ; 1791 ; BRANCH ON KEYBOARD ENTRY 1792 ;0B82 12168E 1793 KEYBD: LCALL BOP0B85 900801 1794 MOV DPTR,#DISPLAY --CONTROL0B88 7440 1795 MOV A,#40H ;READ KEYBOARD0B8A F0 1796 MOVX @DPTR,A0B8B A3 1797 INC DPTR0B8C EO 1798 MOVX A,@DPTR0B8D 23 1799 RL A0B8E 547E 1800 ANL A,#01111110B ;MASK ACTIVE KEYS0B90 F8 1801 MOV R0,A ;SAVE COPY0B91 900B9D 1802 MOV DPTR,#ADTABLE0B94 04 1803 INC A0B95 93 1804 MOVC A,@A+DPTR ;CREATE RETURN ADDRESS057D FB 982 MOV R3,A057E 7C00 983 MOV R4,#00H0580 B1E8 984 ACALL BINMUL0582 AA23 985 MOV R2,23H ;DIVIDE BY 1000584 AB24 986 MOV R3,24H ;ADD 50 FIRST FOR ROUNDING0586 AC25 987 MOV R4,25H0588 7D32 988 MOV R5,#50058A 7E00 989 MOV R6,#00H058C 7F00 990 MOV R7,#00058E B1C1 991 ACALL BINADD0590 AA20 992 MOV R2,20H0592 AB21 993 MOV R3,21H0594 AC22 994 MOV R4,22H0596 7D64 995 MOV R5,#1000598 7E00 996 MOV R6,#00059A 7F00 997 MOV R7,#00059C D1AD 998 ACALL BINDIV059E A820 999 MOV R0,20H ;STORE IN TOW PLACES05A0 A921 1000 MOV R1,21H05A2 AA20 1001 MOV R2,20H05A4 AB21 1002 MOV R3,21H05A6 AC22 1003 MOV R4,22H05A8AD59 1004 MOV R5,DAC --ADJUST105AA AE5A 1005 MOV R6,DAC --ADJUST1+105AC 7F00 1006 MOV R7,#00H05AE B1D4 1007 ACALL BINSUB ;SUBSTRACT NEW FROM 2% VALUE05B0 4004 1008 JC DACCY ;IF CARRY THEN USE OLD VALUE05B2 8859 1009 MOV DAC --ADJUST1,R005B4 895A 1010 MOV DAC --ADJUST1+1,R105B6 7959 1011 DACCY: MOV R1,#DAC --ADJUST105B8 901000 1012 MOV DPTR,#ANALOG --LO05BB 1214DC 1013 LCALL DAC505BE D0D0 1014 CLEAR OUT: POP PSW ;RETURN RBANK SELECTS05C0 22 1015 RET ;RETURN TO INT HANDLE 1016 ;OR TO CALLING SUBROUTINE 1017 ;IF NOT AN ACTUAL INTERRUPT 1018 1019 1020 1021 ; 1022 ; 1023 ;********** BINARY NUMBER MATH ROUTINES ********** 1024 ; 1025 ;W+X=Y W-X=Y W/X=YZ W*X=YZ 1026 ; 1027 ;05C1 E51A 1028 BINADD: MOV A,01AH05C3 251D 1029 ADD A,01DH05C5 F520 1030 MOV 20H,A05C7 E51B 1031 MOV A,1BH05C9 351E 1032 ADDC A,1EH05CB F521 1033 MOV 21H,A05CD E51C 1034 MOV A,1CH05CF 351F 1035 ADDC A,1FH05D1 F522 1036 MOV 22H,A__________________________________________________________________________
In addition to a source which may be adjusted by a potentiometer and the use of a computer as is done in the preferred embodiment, a hardward circuit may be used as shown in FIG. 1 in which a keyboard 1002 initiates clock pulses from a source 1004 and a value into the updating circuit 1006. A source of pulses from the tachometer is applied through conductor 400 to the updating circuit and the number of tachometer pulses in one cycle of the pump are counted sequentially and compared with an idealized number, with the current course being increased if the number lags so that the computer averages the amount of flow across a cycle of the pump to maintain a constant average flow rate by admusting the current source in addition to the other adjustments hereinbefore described.
To monitor the tachometer pulses, the updating circuit includes first and second counters 1010 and 1012, first and second digital-to-analog converters 1014 and 1016 and a comparator 1018. The counter 1010 has counted into it from the clock 1004 the clock pulses in a cycle of the pump before being reset and the clock rate is set to equal the number of tachometer pulses which should be received in one pump cycle. The counter 1012 is reset by the same pulse that resets the counter 1010 but counts the tachometer pulses as they actually occur. Digital-to-analog converter 1014 generates an analog voltage equivalent to the counts in counter 1010 and digital-to-analog converter 1016 generates an analog signal equivalent to the counts of counter 1012. The comparator 1018 compares the analog outputs from the digital-to-analog converters 1014 and 1016 and adjusts the current source 1003 with the signal so as to maintain a signal on conductor 46 which will compensate for deviations of flow from the pump from cycle to cycle.
Before operating the pump, it is calibrated to avoid cavitation while the motor accelerates from the start of a refill cycle to pull fluid into the pump until a predetermined period of time has elapsed from the start of the acceleration. This is accomplished by adjusting potentiometers 916 and 912 (FIG. 29), 514 (FIG. 15) and 857 (FIG. 27) while pumping water and monitoring the pressure output from stroke to stroke to detect cavitation. The values, which affect the acceleration, when properly set reduce the cavitation and variation in flow rate with pressure variations and may be maintained for maximum operation of the pump.
Once the pump is calibrated, it is operated by setting a flow rate, priming the pump, filling its cylinder and expelling fluid. In expelling the fluid, near an end portion of the stroke, the pump is run at a constant speed until it reaches the end of the expulsion stroke, at which time a refill signal is generated and the piston begins a refill stroke in a return direction. When it reaches a start of the refill stroke, the pump motor begins to accelerate at the controlled rate and continues to accelerate for a predetermined amount of time related to the operating conditions, at which time it slows to the preset rate for constant flow.
In setting a flow rate in the preferred embodiment, the flow rate is keyed into the keyboard and a software circuit retains it, generating a set point signal for application to an analog voltage generator of a conventional type. The analog set point signal controls the flow rate.
The preset flow rate is compared with tachometer pulses generated during the forward stroke of the piston of the pump and, if the average pumping rate is below that preset, the voltage on conductor 46 is increased.
Although a computer is used for this function in the preferred embodiment, it can be accomplished by a hardware circuit such as that shown in FIG. 31 in which a count representing an ideal tachometer rate is set into a counter 1010 (FIG. 31) and converted to a digital-to-analog signal in the digital-to-analog converter 1014. The tachometer pulses as they are counted on conductor 400 are also converted to an analog signal in digital-to-analog converter 1016 and the analog signals are compared to adjust the current source so that a basic linear feedback circuit related to liquid influent flow into the chromatographic column and injector system 18 (FIG. 1) is provided.
Of course, the current for conductor 46 may be set by a simple source of potential and variable resistor or by any other technique in which a current directly proportional to the flow rate is provided. This current will, in general, control through a linear circuit the flow rate regardless of how it is obtained and exert a tendency to maintain it constant as influent to the chromatographic column.
During a refill cycle and the first part of the cycle forcing fluid out of the pump, the motor 50 (FIG. 3) receives a signal from the nonlinear flow rate control circuit 42 (FIG. 2 and 9) having a time duration controlled by a timer and initiated at a point during the refill cycle and continuing for a time thereafter related to rate of flow which has been set for flow into the chromatographic column. The time of acceleration is related to the charge on capacitor 150 (FIG. 5) which is modulated by transistor 716 (FIG. 23) in response partly to the signal on conductor 46 (FIG. 23) from the set point value. The amount of acceleration is related to the closed loop servo signal which was last driving the pump, that value being obtained by a sample and hold circuit electrically connected to the output of the servo amplifier to store the signal during the last part of a pumping cycle when the pump is pumping at a constant rate under closed loop control of a motor speed rotation signal. The sample and hold amplifier circuit (FIGS. 26 and 28) stores a signal on a capacitor 900 and 892 (FIG. 28). The rate of acceleration is adjusted by offset and multiplication values during calibration by adjusting potentiometers 916 and 912. The signal from potentiometer 912 is applied as a closed loop control signal to the amplifier 580 (FIG. 17) in which the feedback signal has been closed by analog switch 914 and the amplifier 910.
With this arrangement, the pump is maintained during a portion of a pumping cycle at a constant speed under a tachometer feedback circuit using analog circuitry and a digital control which adusts the constant current control for the flow rate. During the refill cycle, the motor is accelerated continuously while the piston is controlled by a cam to accelerate and decelerate to zero and then accelerate again, with the motor acceleration terminating at a time controlled by a timer to reduce pulsations in flow to a minimum.
From the above description, it can be understood that the pump of this invention has several advantages, such as: (1) the time during which no liquid is pumped through the outlet port is low; (2) the pump is relatively uncomplicated because the acceleration time of the motor is time-limited rather than distance limited; (3) the pump is able to accomodate a wider range of flow rates without cavitation; (4) the pump maintains an accelerating velocity during the return portion while refilling coming to a stop at the end and accelerating upwardly under constant positive driving of a motor through a cam, with the motor receiving a continuous accelerating voltage so as to reduce noise which might otherwise be caused by inertial effects as the motor speed is changed; (5) the average flow rate is continuously monitored and adjusted by adjusting a current input signal representing the preset flow rate of fluid; and (6) the flow rate remains constant as pressure varies.
Although a preferred embodiment of the invention has been described with some particularity, many modifications and variations are possible in the preferred embodiment without deviating from the invention. Therefore, it is to be understood that, with the scope of appended claims, the invention may be practiced other than as specifically described.
|
To provide smooth constant flow from a pump, a chromatographic system comprises: a chromatographic column having an inlet; a pump for supplying fluid to the inlet of the chromatographic column; a power means for the pump motor; positive and negative feedback loop means for controlling said power means; means for energizing and said positive and negative feedback control means; said negative feedback control means receiving a signal from said means for measuring flow rate and including means for comparing said signal with said corrected flow rate reference signal while said second feedback loop is energized to generate an error signal controlling said power means; and said positive feedback control means applying an acceleration voltage to said motor from a time a preset period after the initiation of a return stroke of said piston until after a timed duration.
| 5
|
FIELD OF THE INVENTION
[0001] The present invention relates to a mold steel and a mold thereof, and particularly relates to a mold steel excellent in hardness and corrosion resistance, and a mold thereof.
BACKGROUND OF THE INVENTION
[0002] In recent years, plastic products with which hard glass fiber is mixed for attaining high strength have increased. In injection molding of such plastic products, wear of a mold is actualized. When the mold wears, surface quality of the products is deteriorated by transfer thereof to the products. The products deteriorated in the surface quality are unmarketable and discarded. It is therefore important that the mold does not wear, and in order to ensure wear resistance, high hardness is required for the mold.
[0003] Conventionally, the hardness of the mold used for the injection molding of the plastics with which the hard glass fiber is mixed is mainly from 45 to 55 HRC (from the viewpoint of workability, the mold tempered to a state where the hardness is lower than the above is used in some cases).
[0004] In the mold for molding the plastic product, flow passages for temperature adjustment are generally provided in the inside thereof, and cold water, hot water, vapor or the like is allowed to flow through the flow passages to perform temperature control of the mold. However, in the mold with low corrosion resistance, the flow passages are narrowed with rust, and it becomes unable to ensure a predetermined flow rate (the cold water, the hot water, the vapor or the like), resulting in interfering with the temperature control. Further, when the rust is more increased, the flow passages are clogged with the rust, and the flow passages become useless. Furthermore, in the mold with low corrosion resistance, a crack is generated with a rust part as a starting point, and development thereof causes breakage of the mold or leakage of the cold water, the hot water, the vapor or the like from the crack penetrating to a design surface, which sometimes has an adverse influence on the resin product. In addition, a surface of the mold is sometimes corroded by a gas generated from the resin to be molded. When the corroded part is transferred to the product, the surface quality thereof is deteriorated. For such reasons, high corrosion resistance is required for the mold.
[0005] Additionally, during use thereof as the mold, thermal stress or mechanical stress is repeatedly applied thereto. In order to avoid breakage thereof under such a severe use environment, fineness of crystal grains is required for the mold.
[0006] The mold for plastic injection molding which is required to have the hardness and the corrosion resistance (also including parts constituting a part of the mold) is generally produced through steps of melting→refining→casting→homogenizing heat treatment→hot working→intermediate heat treatment→annealing→machine work 1 (rough machining)→quenching→tempering→machine work 2 (finish machining)→mirror polishing or texturing.
[0007] In addition, surface modification (such as PVD, CVD, nitriding, shot blasting or shot peening) is applied in some cases, as needed.
[0008] In this production process, (1) no precipitation of grain boundary carbides after the hot working, (2) good annealability and (3) no precipitation of pearlite during the quenching are required for a mold steel.
[0009] In the hot working, the steel is in a state of a γ single phase, and all of carbon and carbide forming elements are solid-soluted in a matrix. During cooling after the hot working, the solid solubility of the elements is decreased by a reduction in temperature, and the carbides are sometimes precipitated in γ grain boundaries. The grain boundary carbides precipitated after the hot working cannot be removed by subsequent heat treatment (annealing, quenching or tempering). The grain boundary carbides become foreign matter dispersed in the matrix, which is an obstacle for obtaining a uniform and smooth surface by the mirror polishing. Furthermore, the grain boundary carbides also become starting points of breakage due to repeated stress during use thereof as the mold. Therefore, “(1) difficulty in precipitation of grain boundary carbides” is required.
[0010] When the annealability is poor, complicated annealing conditions over a long time are necessary for softening, which causes an increase in material cost. It is therefore required that softening to a state capable of performing the above-mentioned machine work 1 is achieved by simple heat treatment, that is, “(2) good annealability”.
[0011] Also pearlite precipitated during the quenching cannot be removed by the subsequent tempering. Pearlite becomes foreign matter dispersed in the matrix, which is an obstacle for obtaining the uniform and smooth surface by the mirror polishing. Furthermore, pearlite also becomes starting point of breakage due to repeated stress during use thereof as the mold. Therefore, “(3) difficulty in precipitation of pearlite” is required.
[0012] Conventionally, JIS SUS420J2 has been frequently used in a mold or parts thereof requiring corrosion resistance and a high hardness of about 52 HRC. The components thereof are 0.4% of C, 0.9% of Si, 0.4% of Mn, 0.2% of Ni, 13% of Cr and 0.015% of N. The SUS420J2 satisfies the condition of (2) good annealability described above, and is softened to 87-96 HRB only by simple annealing treatment of cooling it from 850-950° C. to 650° C. at 15-60° C./Hr, followed by natural cooling.
[0013] However. SUS420J2 does not satisfy the above-mentioned conditions of (1) and (3).
[0014] In particular, even when quench-cooled from a quenching temperature of 1,030° C. at a high rate of 50° C./min, the precipitation of pearlite cannot be avoided.
[0015] The quench-cooling rate in the inside of the mold is generally from 10 to 40° C./min (in a temperature range of 550 to 850° C. at which pearlite is precipitated), and therefore, the precipitation of pearlite becomes unavoidable in the inside of the mold of SUS420J2 to increase a risk of breakage during use thereof as the mold.
[0016] To the above-mentioned problem, high N stainless steel in which the components of SUS420J2 are largely changed is sometimes used. In this steel, the above-mentioned problem of (1) is avoided by decreasing the C content. The N content is increased, thereby compensating for a decrease in strength due to decreasing the C content. Also, in this steel, the above-mentioned problem of (3) is avoided by increasing the Mn content or the Ni content together with decreasing the C content. However, as a result of such component adjustment, quenchability is excessively increased, and therefore, the above-mentioned condition of (2) cannot be achieved. As a result, cost of the annealing or the machine work 1 (rough machining) is increased, or the time of delivery is forced to be delayed. Further, a γ memory effect is developed during the quenching because of its poor annealability, and coarse grains during the hot working are taken over also during the quenching, resulting in easy generation of cracks during use as the mold.
[0017] As described above, the mold for plastic injection molding requires (1) no precipitation of grain boundary carbides after hot working, (2) good annealability and (3) no precipitation of pearlite during quenching, in addition to the high hardness and the high corrosion resistance. However, no mold steel and mold that satisfy these characteristics have hitherto been provided.
[0018] The following Patent Documents 1 to 7 disclose steels containing 10.5 to 12.5% of Cr, which is within the range of the present invention. However, all of these steels are not steels for plastic injection molding molds, and different from the present invention in use thereof, as shown below. Furthermore, these steels are different also in essential elements and characteristics under consideration.
[0019] Patent Document 1 discloses a free-cutting tool steel having 40 to 47 HRC. However, the steel described in Patent Document 1 is different from the present invention in that it is silent on the plastic injection molding mold with the high hardness and the high corrosion resistance, that S is essentially added for free-cutting, and that the hardness level is lower than that of the present invention. Assuming this steel to be applied to the plastic injection molding mold, it is easily presumed that predetermined mirror finishing properties cannot be ensured due to an influence of the free-cutting component, and that wear resistance thereof is poor.
[0020] In addition, an example of containing Cr in a range of 7.05 to 15.0% is not disclosed, and therefore, an effect of containing Cr in the above range is not demonstrated. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0021] Patent Document 2 discloses a free-cutting tool steel having 45 to 63 HRC. However, the steel described in Patent Document 2 is also different from the present invention in that it is silent on the plastic injection molding mold with the high hardness and the high corrosion resistance, that S is essentially added for free-cutting, and that the hardness level is lower than that of the present invention. Assuming this steel to be applied to the plastic injection molding mold, it is easily presumed that predetermined mirror finishing properties cannot be ensured due to an influence of the free-cutting component. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0022] Patent Document 3 discloses an alloy steel for hot working. However, the steel described in Patent Document 3 is silent on the plastic injection molding mold with the high hardness and the high corrosion resistance, and basic components are C, Si, REM and N in some cases. It is therefore easily presumed that quenching is not attained, and moreover, that the corrosion resistance is not obtained. In addition, for Cr as a selective element, an example of containing Cr within a range of 2.5 to 13.0% is not disclosed, and therefore, an effect of containing Cr within the above range is not demonstrated. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0023] Patent Document 4 discloses a steel for a die-casting die having a carbide area ratio of 5.5 to 30% and having excellent erosion resistance. However, the steel described in Patent Document 4 is different from the present invention in that Ni is not essential and is added in an amount of as low as 0.2% (Example), even if added, which does not demonstrate an effect of the high Ni content, and that although Mo+0.5W is essential, it is added in an amount of as large as at least 1.95% (Example), which does not demonstrated an effect of the low Mo content. In addition, an extremely large amount of C is contained because carbides are formed in large amounts. When the steel is applied to the plastic injection molding mold, it is easily presumed that the mirror finishing properties and the corrosion resistance are deteriorated due to an influence of the carbides, and that breakage due to the carbides serving as starting points is generated. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0024] Patent Document 5 discloses a spring steel wire having a diameter of 4.5 to 20 mm. However, the steel wire described in Patent Document 5 is different from the present invention in that it is silent on the plastic injection molding mold, and that V is not essential.
[0025] Even when V is selectively added, it is added in an amount of as large as 0.5% (Example), which does not demonstrated an effect of the low V content. Needless to say, the steel wire having a diameter of 4.5 to 20 mm cannot be applied to the mold. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0026] Patent Document 6 and Patent Document 7 disclose oil well stainless steel pipes. The stainless steel pipes described in these Patent Documents are different from the present invention in that these are silent on the plastic injection molding mold, and that Ni, Mo and V are not essential. Furthermore, the content of Si is as low as 0.31% or less (Example), which does not demonstrate an effect of the high Si content. The amount of Ni selectively added is as high as at least 1.63% (Example), which does not demonstrate an effect of the low Ni content. The amount of Mo selectively added is as high as at least 0.75% (Example), which does not demonstrate an effect of the low Mo content. Needless to say, the steel pipes cannot be applied to the mold. There is also no attention to the annealability or the precipitation of the grain boundary carbides and pearlite.
[0027] On the other hand, the following Patent Document 8 and Patent Document 9 disclose high Cr steels for plastic injection molding molds. However, in the steels described in these Patent Documents, the amount of Cr added is as high as 12.5% or more, and therefore, the steels are different from the present invention.
[0028] In addition, Patent Document 10 discloses a plastic injection molding mold steel which overlaps with the present invention in the amount of Cr added. However, the present invention is directed to the component ranges of Si, Mn and Ni which are not disclosed as Examples in Patent Document 10, and finds effects not obtained by the technique disclosed in this Patent Document.
Patent Document 1: JP-A-57-73171 Patent Document 2: JP-A-57-73172 Patent Document 3: JP-A-58-113352 Patent Document 4: JP-A-2007-197784 Patent Document 5: JP-A-2007-314815 Patent Document 6: JP-A-2008-297602 Patent Document 7: JP-A-2009-167476 Patent Document 8: JP-A-8-253846 Patent Document 9: JP-T-2004-503677 Patent Document 10: JP-T-2010-539325
SUMMARY OF THE INVENTION
[0039] The present invention has been made in view of circumstances as described above, and an object thereof is to provide a mold steel having difficulty in precipitation of grain boundary carbides, good annealability and difficulty in precipitation of pearlite, when a mold is produced, and having high hardness, excellent corrosion resistance and fine prior austenite crystal grains, when it has been formed into a mold; and a mold thereof.
[0040] Namely, the present invention relates to the following items (1) to (8).
[0000] (1) A mold steel having a composition including, in terms of mass %:
[0041] 0.220%≦C≦0.360%;
[0042] 0.65%≦Si<1.05%;
[0043] 0.43%≦Mn≦0.92%;
[0044] 0.43%≦Ni≦0.92%;
[0045] 0.67%≦0.5Mn+Ni≦1.30%;
[0046] 10.50%≦Cr<12.50%;
[0047] 0.05%≦Mo<0.50%;
[0048] 0.002%≦V<0.50%;
[0049] 0.001%≦N≦0.160%; and
[0050] 0.300%≦C+N≦0.420%,
[0051] with the remainder being Fe and unavoidable impurities.
[0052] Usually, in the mold steel, components shown below are contained as unavoidable impurities in the following ranges.
[0053] P≦0.05%, S≦0.006%, Cu≦0.30%, Al≦0.10%, W≦0.30%, O≦0.01%, Co≦0.30%, Nb≦0.004%, Ta≦0.004%, Ti≦0.004%, Zr≦0.004%, B≦0.0001%, Ca≦0.0005%, Se≦0.03%, Te≦0.005%. Bi≦0.01%, Pb≦0.03%, Mg≦0.02%, REM≦0.10%, etc.
[0000] (2) The mold steel according to (1), further including, in terms of mass %, at least one of:
[0054] 0.30%<W≦5.00%; and
[0055] 0.30%<Co≦4.00%.
[0000] (3) The mold steel according to (1) or (2), further including, in terms of mass %, at least one of:
[0056] 0.004%<Nb≦0.100%;
[0057] 0.004%<Ta≦0.100%;
[0058] 0.004%<Ti≦0.100%; and
[0059] 0.004%<Zr≦0.100%.
[0000] (4) The mold steel according to any one of (1) to (3), further including, in terms of mass %:
[0060] 0.10%<Al≦1.20%.
[0000] (5) The mold steel according to any one of (1) to (4), further including, in terms of mass %:
[0061] 0.30%<Cu≦3.0%.
[0000] (6) The mold steel according to any one of (1) to (5), further including, in terms of mass %:
[0062] 0.0001%<B≦0.0050%.
[0000] (7) The mold steel according to any one of (1) to (6), further including, in terms of mass %, at least one of:
[0063] 0.006%<S≦0.050%;
[0064] 0.0005%<Ca≦0.2000%;
[0065] 0.03%<Se≦0.50%;
[0066] 0.005%<Te≦0.100%;
[0067] 0.01%<Bi≦0.50%; and
[0068] 0.03%<Pb≦0.50%.
[0000] (8) A mold including the mold steel according to any one of (1) to (7).
[0069] In the present invention, the “mold” includes not only a mold body but also mold parts such as a pin used by being assembled to it. Further, the “mold” includes a mold including the steel of the present invention, to which surface treatment is performed.
[0070] The present invention as described above is characterized in that precipitation of grain boundary carbides and pearlite is suppressed by decreasing the C content, decreasing the Cr content, increasing the Mn content, increasing the Ni content and adding Mo to SUS420J2.
[0071] According to such a present invention, hardness, corrosion resistance and annealability are ensured to the same as those of SUS420J2, and moreover, the precipitation of the grain boundary carbides and pearlite can be suppressed.
[0072] In SUS420J2, the carbides to be precipitated are Cr-based carbides, and therefore, in order to suppress the precipitation of the carbides, it is effective to decrease the Cr content. On the other hand, however, when the Cr content is excessively decreased, the corrosion resistance or the annealability is deteriorated.
[0073] Then, in the present invention, the precipitation of the grain boundary carbides and pearlite has been suppressed while ensuring the good annealability by satisfying 10.50%≦Cr<12.50% without excessively decreasing the Cr content, and adding Mn, Ni and Mo in appropriate amounts under this Cr content.
[0074] In the present invention, in order to compensate for a decrease in the hardness due to a decrease in the C content, the N content has been increased. Further, an effect of compensating for the hardness by secondary hardening of Mo has been provided by addition of Mo.
[0075] Also, the annealability which is the same as that of SUS420J2 has been ensured by not excessively increasing the Mn, Ni and Mo contents, and the corrosion resistance which is the same as that of SUS420J2 has been ensured by decreasing the C content, not excessively decreasing the Cr content, and increasing the Ni and Mo contents.
[0076] In the present invention, further, austenite crystal grain boundaries are pinned with the carbides during the quenching, and in order to maintain fine crystal grains, the V content has been increased. This is for the purpose of compensating for a decrease in Cr-based carbides due to decreasing of the C and Cr contents during the quenching with V-based carbides. A part of V solid-soluted during the quenching exerts an effect of compensating for the hardness by the secondary hardening.
[0077] The present invention described above is suitable particularly as a plastic injection molding mold steel or a rubber molding mold steel including injection molding. However, the present invention is also suitable as a steel for a mold such as a cold press forming mold, a hot stamp mold for steel plates or a tableting pestle mold for solidifying a drug powder to tablets.
[0078] According to the present invention, a mold steel and a mold can be provided, in which when the mold is produced, difficulty in precipitation of grain boundary carbides, good annealability and difficulty in precipitation of pearlite are satisfied, and when the mold has been obtained, the mold has high hardness and excellent corrosion resistance and has fine prior austenite crystal grains.
BRIEF DESCRIPTION OF THE DRAWING
[0079] FIG. 1 is a graph showing an influence of the Si content on machinability.
[0080] FIG. 2 is a graph showing an influence of the Si content on thermal conductivity.
[0081] FIG. 3 is a graph showing an influence of the Mn content on pearlite precipitation.
[0082] FIG. 4 is a graph showing an influence of the Mn content on annealability.
[0083] FIG. 5 is a graph showing an influence of the Mn content and the Ni content on pearlite precipitation.
[0084] FIG. 6 is a graph showing an influence of the Mn content and the Ni content on annealability.
[0085] FIG. 7 is a graph showing an influence of the Mo content on delta ferrite precipitation.
DETAILED DESCRIPTION OF THE INVENTION
[0086] The reasons for the limitation of the respective chemical components in the present invention are described below.
[For Chemical Components of Above-Described Item (1)]
[0087] 0.220%≦C≦0.360%
[0088] In the case of C<0.220%, it is difficult to stably obtain the high hardness (45 HRC or more) necessary for ensuring the high wear resistance. In the case of 0.360%<C, the corrosion resistance or weldability is deteriorated. Furthermore, in the case of 0.360%<C, the grain boundary carbides or pearlite is easily precipitated. In addition, in the case of 0.360%<C, residual austenite during the quenching is increased, resulting in a difficulty to adjust the hardness or the size in the tempering.
[0089] The preferred range of the C content is 0.230%≦C≦0.350% in which a balance of various characteristics is excellent, and it is 0.230%<C≦0.290% when the N content is large and 0.290%≦C≦0.350% when the N content is small.
[0090] 0.65%≦Si<1.05%
[0091] In the case of Si<0.65%, machinability during the machine work is deteriorated. Furthermore, in the case of Si<0.65%, there is also a disadvantage that unevenness of carbide distribution in a metal structure in an annealed state is increased.
[0092] On the other hand, in the case of 1.05%≦Si, the thermal conductivity is largely decreased. In order to enhance the productivity of injection molding, it is necessary to shorten the hardening time of plastic injected into a mold, and for that purpose, a mold material having a high thermal conductivity is required. Si has an action to discharge C from a steel, and therefore, in the case of 1.05%≦Si, the grain boundary carbides or pearlite is easily precipitated. Also, delta ferrite is easily generated. When delta ferrite remains, an adverse influence is exerted on mirror polishing properties, and it may act as a starting point of breakage of the mold. The higher the temperature is, the more easily delta ferrite is precipitated. In order to avoid delta ferrite, therefore, a high Cr content and high Si content steel is forced to be subjected to homogenizing heat treatment or hot working at low temperature. By lowering the temperature, it becomes difficult to decrease segregation, which exerts an adverse influence on the mirror polishing properties or texturability.
[0093] The preferred Si content range is 0.68%≦Si≦1.02% in which a balance of these characteristics is excellent, and more preferably 0.72%≦Si≦50.98%.
[0094] FIG. 1 shows an influence of the Si content on the machinability.
[0095] A material containing 0.32% of C, 0.67% of Mn, 0.71% of Ni, 12.2% of Cr, 0.22% of Mo, 0.24% of V, and 0.040% of N as basic components and varied in the Si content was softened to 97 HRB or less by annealing in which the material was cooled from 915° C. to 650° C. at 15° C./Hr, followed by natural cooling. This component system is lower in the C content and the Cr content than SUS420J2, and the carbides are contained in smaller amounts. Therefore, when compared in the same Si content of 1%, the component system has better machinability than SUS420J2. In the case of 0.65%≦Si, the machinability thereof is equivalent to or better than that of the SUS420J2 system. Therefore, in the present invention, the Si content is specified as 0.65%≦Si.
[0096] FIG. 2 shows an influence of the Si content on the thermal conductivity.
[0097] A material containing 0.32% of C, 0.67% of Mn, 0.71% of Ni, 12.2% of Cr, 0.22% of Mo, 0.24% of V and 0.040% of N as basic components and varied in the Si content was quenched from 1,030° C., and tempered at 505° C. Thereafter, the thermal conductivity thereof was measured at room temperature. This component system is lower in the C content and the Cr content, but higher in the Mn content and the Ni content than SUS420J2. Therefore, influences of the increased contents and decreased contents are cancelled, and the thermal conductivity thereof is close to that of SUS420J2. In the case of 1.05%≦Si, the thermal conductivity thereof is more deteriorated than that of SUS420J2. Therefore, in the present invention, the Si content is specified as Si<1.05%.
[0098] 0.43%≦Mn≦0.92%
[0099] In the case of Mn<0.43%, the effect of stabilizing austenite to suppress the precipitation of pearlite is small. Furthermore, in the case of Mn<0.43%, a risk of the precipitation of delta ferrite is increased.
[0100] On the other hand, in the case of 0.92%<Mn, the annealability is deteriorated. Furthermore, in the case of 0.92%<Mn, the thermal conductivity is also largely decreased. In addition, in the case of 0.92%<Mn, residual austenite during the quenching is increased, resulting in a difficulty to adjust the hardness or the size in the tempering.
[0101] The preferred range of the Mn content is 0.46%≦Mn≦0.90% in which a balance of various characteristics is excellent, and more preferably 0.50%≦Mn≦0.88%.
[0102] In the case of the high Cr content steel, addition of Ni is very effective for the stabilization of austenite (the suppression of the precipitation of pearlite). However, addition of a large amount of Ni causes a significant increase in cost. Therefore, an increase in material cost is suppressed by using Mn which is an element stabilizing austenite like Ni and inexpensive.
[0103] FIG. 3 shows an influence of the Mn content on the critical cooling rate for the pearlite precipitation.
[0104] For a material containing 0.31% of C, 0.93% of Si, 0.72% of Ni, 12.3% of Cr, 0.23% of Mo, 0.22% of V and 0.039% of N as basic components and varied in the Mn content, when the cooling rate from 1,030° C. was varied, the lowest cooling rate at which the precipitation of pearlite was stopped was evaluated as the critical cooling rate. The lower the critical cooling rate is, the more hardly pearlite is precipitated. This is therefore preferred.
[0105] As shown in FIG. 3 , the critical cooling rate decreases with an increase in the Mn content, and reaches 10° C./min at a Mn content of 0.43%. The quenching rate in the inside of the mold is generally from 10 to 40° C./min in a temperature range of 550 to 850° C. in which pearlite is precipitated. Therefore, when the critical cooling rate for the pearlite precipitation is 10° C./min, a risk of generating pearlite in actual quenching in the mold is extremely decreased. Therefore, in the present invention, the Mn content is specified as 0.43%≦Mn.
[0106] FIG. 4 shows an influence of the Mn content on the annealability.
[0107] When a material containing 0.31% of C, 0.93% of Si, 0.72% of Ni, 12.3% of Cr, 0.23% of Mo, 0.22% of V and 0.039% of N as basic components and varied in the Mn content was cooled from 915° C. to 650° C. at 15° C./Hr, followed by natural cooling, the hardness of the material was shown to the Mn content. When the hardness is 97 HRB or less, the material is preferred because of its softness and easy mechanical workability. The hardness increases with an increase in the Mn content to reach 97 HRB at a Mn content of 0.92%. Therefore, in the present invention, the Mn content is specified as Mn≦0.92%.
[0108] 0.43%≦Ni≦0.92%
[0109] In the case of Ni<0.43%, the effect of stabilizing austenite to suppress the precipitation of pearlite is small. Furthermore, a risk of the precipitation of delta ferrite is increased.
[0110] On the other hand, in the case of 0.92%<Ni, the annealability is deteriorated. Furthermore, the thermal conductivity is also largely decreased. In the case of 0.92%<Ni, residual austenite during the quenching is increased, resulting in a difficulty to adjust the hardness or the size in the tempering. Effects of Ni are similar to those of Mn.
[0111] The preferred range of the Ni content is 0.45%≦Ni≦0.90% in which a balance of various characteristics is excellent, and more preferably 0.48%≦Ni≦0.88%.
[0112] 0.67%≦0.5Mn+Ni≦1.30%
[0113] In order to achieve both the annealability and the quenchability at high levels, the value of 0.5Mn+Ni is specified as described above. In the case of 0.5Mn+Ni<0.67%, the annealability is satisfactory, but the quenchability is insufficient. Furthermore, in the case of 0.5Mn+Ni<0.67%, a risk of the precipitation of delta ferrite is also increased.
[0114] On the other hand, in the case of 1.30%<0.5Mn+Ni, the quenchability is satisfactory, but the annealability is insufficient. In the case of 1.30%<0.5Mn+Ni, residual austenite during the quenching is increased, resulting in a difficulty to adjust the hardness or the size in the tempering.
[0115] FIG. 5 shows a state of precipitation of pearlite during the quenching at 10° C./min. A material contained 0.32% of C, 0.91% of Si, 12.2% of Cr, 0.23% of Mo, 0.23% of V and 0.038% of N as basic components, and the Mn content and the Ni content were varied. Regions where pearlite was precipitated by cooling from 1,030° C. at 10° C./min were expressed by “x”, and regions where pearlite was not precipitated were expressed by “∘”. A boundary between both is 0.5Mn+Ni=0.67%, and in the case of more than this, a risk of the precipitation of pearlite in the actual quenching in the mold can be considerably decreased. Therefore, 0.5Mn+Ni is specified as 0.67%≦0.5Mn+Ni.
[0116] FIG. 6 shows a state of softening in the annealing at 15° ° C./Hr. A material contained 0.32% of C, 0.91% of Si, 12.2% of Cr, 0.23% of Mo, 0.23% of V and 0.038% of N as basic components, and the Mn content and the Ni content were varied. Regions where the hardness exceeded 97 HRB in the annealing of cooling from 915° C. at 15° C./min were expressed by “x”, and regions where the hardness was 97 HRB or less were expressed by “∘”. A boundary between both is 0.5Mn+Ni=1.30%, and in the case of less than this, the material can be softened by simple annealing. Therefore, 0.5Mn+Ni is specified as 0.5Mn+Ni≦1.30%.
[0117] As described above, 0.5Mn+Ni is a very useful index in the case of studying a balance of the quenchability and the annealability.
[0118] 10.50%≦Cr<12.50%
[0119] In the case of Cr<10.50%, the corrosion resistance is deteriorated. Furthermore, in the case of Cr<10.50%, the annealability is also deteriorated.
[0120] On the other hand, in the case of 12.50%≦Cr, the grain boundary carbides or pearlite is easily precipitated. Furthermore, delta ferrite is also easily precipitated. In addition, in the case of 12.50%≦Cr, the thermal conductivity is largely decreased. In the case of 12.5%≦Cr, residual austenite during the quenching is increased, resulting in a difficulty to adjust the hardness or the size in the tempering.
[0121] The preferred range of the Cr content is 10.70%≦Cr≦12.45% in which a balance of various characteristics is excellent, and more preferably 10.90%≦Cr≦2.40%.
[0122] 0.05%≦Mo<0.50%
[0123] In the case of M<0.05%, the effect of suppressing the precipitation of pearlite is poor. Furthermore, in the case of M<0.05%, contribution of the secondary hardening is small, and when tempered at high temperature, it becomes difficult to stably obtain a hardness of 45 HRC or more.
[0124] On the other hand, in the case of 0.50%≦Mo, the annealability is deteriorated. In addition, delta ferrite is easily precipitated.
[0125] The preferred range of the Mo content is 0.07%≦Mo≦0.46% in which a balance of various characteristics is excellent, and more preferably 0.09%≦Mo≦0.43%.
[0126] FIG. 7 shows an influence of the Mo content on the area ratio of delta ferrite.
[0127] A material contained 0.23% of C, 1.04% of Si, 0.45% of Mn, 0.44% of Ni, 12.47% of Cr, 0.46% of V and 0.004% of N as basic components, and the Mo content was varied. The material was heated at 1,280° C. corresponding to the temperature of homogenization for decreasing the segregation, and quenched by rapid cooling. The area ratio of delta ferrite in a structure thereof was evaluated.
[0128] As shown in FIG. 7 , when the Mo content is decreased, delta ferrite is hardly precipitated. When the Mo content is 0.50% or less, the area ratio is zero. In the present invention, therefore, the Mo content is specified as Mo<0.50%.
[0129] 0.002%≦V<0.50%
[0130] In the case of V<0.002%, the effect of maintaining the fine austenite crystal grains during the quenching is poor, and a risk that the mold is broken during use by a reduction in toughness is increased. Furthermore, in the case of V<0.002%, there is almost no contribution of the secondary hardening. It is therefore difficult to stably obtain a hardness of 45 HRC or more, when tempered at high temperature.
[0131] On the other hand, in the case of 0.50%≦V, not only the effect of maintaining the fine crystal grains is saturated, but also an increase in cost is caused. In addition, carbonitrides of V are easily precipitated to rather cause the mold to be easily cracked. In the case of 0.50%≦V, delta ferrite is easily precipitated.
[0132] The preferred range of the V content is 0.005%≦V≦0.45% in which a balance of various characteristics is excellent, and more preferably 0.008%≦V≦0.40%.
[0133] 0.001%≦N≦0.160%
[0134] In the case of N<0.001%, the effect of increasing the hardness is poor, and it is difficult to stably obtain a hardness of 45 HRC or more. Furthermore, N has a great influence on the solid solution temperature of V-based carbides. The lower the N content is, the lower the temperature at which the V-based carbides are solid-soluted is. In the case of N<0.001%, therefore, the effect of maintaining the fine austenite crystal grains during the quenching is also poor.
[0135] On the other hand, in the case of 0.1609<N, the effect of increasing the strength or maintaining the fine crystal grains is saturated. Furthermore, in the case of 0.160<N, the time and cost of refining required for addition of N are increased to cause an increase in material cost. Additionally, in the case of 0.160%<N, the carbonitrides of V are easily precipitated to cause the mold to be easily cracked.
[0136] The preferred range of the N content is 0.003%≦N≦0.155% in which a balance of various characteristics is excellent, and more preferably 0.005%<N≦0.150%.
[0137] 0.300%≦C+N≦0.420%
[0138] In the case of C+N<0.300%, the effect of increasing the hardness is poor, and it is difficult to stably obtain a hardness of 45 HRC or more. Furthermore, the V-based carbides are decreased during the quenching, and therefore, the effect of maintaining the fine austenite crystal grains is also poor.
[0139] On the other hand, in the case of 0.420%<C+N, the effect of maintaining the fine crystal grains is saturated. In addition, in the case of 0.420%<C+N, the V-based carbonitrides are increased to cause the mold to be easily cracked. In the case of 0.420%<C+N, residual austenite increases during the quenching, resulting in a difficulty to adjust the hardness or the size in the tempering.
[0140] The preferred range of the C content+the N content is 0.303%≦C+N≦0.415% in which a balance of various characteristics is excellent, and more preferably 0.306%≦C+N≦0.410%.
[For Chemical Components of Above-Described Item (2)]
[0141] In the steel of the present invention, Cr is contained in a large amount, so that the softening resistance thereof is low. When the tempering temperature is high, it is difficult to ensure a hardness of 45 HRC. In such a case, W or Co may be selectively added to ensure the strength. W increases the strength by precipitation of its carbide. Co increases the strength by solid dissolution into a matrix, and at the same time, also contributes to precipitation hardening through changes in carbide morphology. Specifically, it is only required to contain at least one (one element) of:
[0142] 0.30%<W≦5.00%; and
[0143] 0.30%<Co≦4.00%.
[0144] Both the elements cause saturation of the characteristics and a significant increase in cost, when the contents thereof exceed the predetermined amounts.
[For Chemical Components of Above-Described Item (3)]
[0145] When the quenching heating temperature is increased or the quenching heating time is prolonged by unexpected equipment troubles, etc., there is a concern that various characteristics may be deteriorated due to coarsening of the crystal grains. For such cases, Nb, Ta, Ti and Zr are selectively added, and coarsening of the austenite crystal grains can be suppressed by fine precipitates formed by these elements. Specifically, it is only required to contain at least one of:
[0146] 0.004%<Nb≦0.100%;
[0147] 0.004%<Ta≦0.100%;
[0148] 0.004%<Ti≦0.100%; and
[0149] 0.004%<Zr≦0.100%.
[0150] All of the elements excessively form carbides, nitrides or oxides thereof to cause a decrease in the impact value or the mirror polishing properties, when the contents thereof exceed the predetermined amounts.
[For Chemical Components of Above-Described Item (4)]
[0151] Similarly, in order to suppress coarsening of the austenite crystal grains,
[0152] 0.10%<Al≦1.20% can be contained. Al combines with N to form AlN, which has an effect of suppressing transfer of crystal grain boundaries (namely, grain growth) of austenite and is effective for maintenance of the fine grains.
[0153] Also, Al forms a nitride in the steel and contributes to precipitation strengthening, so that it also has an action of increasing the surface hardness of a steel material subjected to nitriding treatment. Use of an Al-containing steel material is effective for the mold in which nitriding treatment is performed for pursuing the higher wear resistance.
[0154] However, the content of Al exceeding the predetermined amount causes a decrease in the thermal conductivity or the toughness.
[For Chemical Components of Above-Described Item (5)]
[0155] In recent years, a mold tends to be increased in size by an increase in size of parts or integration thereof. The large mold is hardly cooled. For this reason, when the large mold of a steel material with low quenchability is quenched, ferrite, pearlite or coarse bainite is precipitated during the quenching to deteriorate various characteristics. The steel of the present invention has considerably high quenchability, and therefore, there is a little concern about such deterioration. However, in case the extremely large mold is treated by a quenching plan of weak cooling intensity. Cu can be added to further increase the quenchability. Specifically, it is only required to contain:
[0000] 0.30%<Cu≦3.0%.
[0156] Cu has also an effect of increasing the hardness by age precipitation. When the content of Cu exceeds the predetermined amount, segregation becomes remarkable to cause deterioration in the mirror polishing properties or the texturability.
[For Chemical Components of Above-Described Item (6)]
[0157] As a measure for improving the quenchability, addition of B is also effective. Specifically,
[0158] 0.0001%<B≦0.0050%
[0000] is allowed to be contained
[0159] B loses the effect of improving the quenchability, when BN is formed. It is therefore necessary that B is present alone in the steel. Specifically, B may be prevented from combining with N by forming a nitride with an element having stronger affinity with N than B. Examples of such elements include the elements described in the above-described item (3). The elements described in item (3) have an effect of fixing N, even when present at an impurity level, but are sometimes added within the ranges specified in item (3), depending on the N content. Even when B combines with N in the steel to form BN, in the case where excessive B is present in the steel, it increases the quenchability.
[0160] B is also effective for improvement of the machinability. In the cases of improving the machinability, it is only required to form BN. BN is similar to graphite in properties, and decreases machining resistance and at the same time improves chip breakability. When B and BN are present in the steel, the quenchability and the machinability are improved at the same time.
[For Chemical Components of Above-Described Item (7)]
[0161] In order to improve the machinability, it is also effective to selectively add S, Ca, Se, Te, Bi and Pb. Specifically, it is only required to contain at least one of:
[0162] 0.006%<S≦0.050%;
[0163] 0.0005%<Ca≦0.2000%;
[0164] 0.03%<Se≦0.50%;
[0165] 0.005%<Te≦0.100%;
[0166] 0.01%<Bi≦0.50%; and
[0167] 0.03%<Pb≦0.50%.
[0168] All of the elements cause saturation of the machinability, deterioration in the hot workability, and a decrease in the impact value or the mirror polishing properties, when the contents thereof exceed the predetermined amounts.
EXAMPLES
[0169] For 20 kinds of steels shown in Table 1, difficulty in precipitation of grain boundary carbides, annealability, difficulty in precipitation of pearlite, grain size during quenching, quenching tempering hardness and corrosion resistance were examined.
[0170] All of 5 kinds of Comparative Steels are used for use requiring hardness or corrosion resistance. Comparative Steel 1 is JIS SUS420J2, Comparative Steel 2 is JIS SUS403, Comparative Steel 3 is JIS SUH1, Comparative Steel 4 is JIS SUH600, and Comparative Example 5 is a steel sold on the market.
[0171] Materials of the 20 kinds of steel shown in Table 1 were each produced by the following procedure. First, molten steel was cast into a 50 kg ingot, and thereafter subjected to homogenizing treatment at 1,240° C. for 12 hours. Then, it was formed into a rod shape having a rectangular cross-section of 60 mm×45 mm. Subsequently, normalizing by heating at 1,020° C. and rapid cooling, and tempering by heating at 620° C. were performed. Further, after heating at 860° C. or 915° C., slow cooling was conducted at 15° C./Hr, thereby performing annealing. Test specimens were cut out from this rod steel and used for various examinations.
[0000]
TABLE 1
Chemical Components (mass %)
C
Si
Mn
Ni
Cr
Mo
V
N
C + N
0.5Mn + Ni
Others
Invention Steel 1
0.318
0.93
0.65
0.65
12.33
0.23
0.23
0.040
0.358
0.975
Invention Steel 2
0.321
0.92
0.65
0.65
12.35
0.24
0.35
0.015
0.336
0.975
Invention Steel 3
0.269
0.92
0.65
0.65
12.34
0.23
0.23
0.090
0.359
0.975
Invention Steel 4
0.272
0.94
0.65
0.65
12.36
0.23
0.35
0.065
0.337
0.975
Invention Steel 5
0.311
0.66
0.44
0.91
10.51
0.06
0.003
0.009
0.320
1.130
W: 3.94
Invention Steel 6
0.290
0.71
0.53
0.87
10.81
0.11
0.011
0.021
0.311
1.135
Co: 2.02
Invention Steel 7
0.248
0.76
0.73
0.73
11.11
0.16
0.024
0.073
0.321
1.095
Nb: 0.03
Invention Steel 8
0.304
0.68
0.82
0.82
11.32
0.21
0.06
0.030
0.334
1.230
Al: 0.23
Invention Steel 9
0.337
0.86
0.91
0.44
11.48
0.26
0.17
0.048
0.385
0.895
Cu: 0.98
Invention Steel 10
0.348
0.91
0.59
0.50
11.64
0.31
0.29
0.057
0.405
0.795
Ti: 0.04, B: 0.004
Invention Steel 11
0.359
0.97
0.64
0.63
11.80
0.36
0.11
0.003
0.362
0.950
S: 0.013
Invention Steel 12
0.240
1.04
0.77
0.77
11.94
0.41
0.41
0.081
0.321
1.155
W: 2.96, Co: 1.03
Invention Steel 13
0.221
0.83
0.87
0.54
12.07
0.45
0.48
0.099
0.320
0.975
Ta: 0.02, Zr: 0.02
Invention Steel 14
0.227
0.74
0.44
0.46
12.21
0.49
0.44
0.114
0.341
0.680
Bi: 0.18
Invention Steel 15
0.292
0.81
0.90
0.84
12.49
0.33
0.38
0.127
0.419
1.290
Bi: 0.10, Pb: 0.15
Comparative Steel 1
0.400
0.90
0.40
0.20
13.00
0.01
0.002
0.015
0.415
0.400
Comparative Steel 2
0.120
0.35
0.75
0.20
12.00
0.01
0.002
0.013
0.133
0.575
Comparative Steel 3
0.470
3.20
0.45
0.20
9.30
0.01
0.002
0.012
0.482
0.425
Comparative Steel 4
0.170
0.35
0.75
0.20
12.00
0.45
0.25
0.075
0.245
0.575
Nb: 0.40
Comparative Steel 5
0.250
0.28
0.60
1.40
13.30
0.35
0.35
0.110
0.360
1.700
<Difficulty in Precipitation of Grain Boundary Carbides>
[0172] Using a block of 15 mm×15 mm×25 mm cut out from the above-mentioned material as a test specimen, evaluation was performed by an experiment simulating a hot working process in a factory. Grain boundary carbides are precipitated during cooling to 800° C. after hot working. Therefore, the block of the test specimen was heated at 1,180° C. simulating the hot working, and cooled to 800° C. at 5° C./min, followed by rapid cooling to freeze the state of the carbides.
[0173] Thereafter, the above-mentioned test specimen was corroded, and the grain boundary carbides were colored. A structure thereof was observed under an optical microscope at 1,000 magnifications. When the grain boundary carbides were remarkably observed, the difficulty in precipitation was determined to be unacceptable and indicated by “x”. When the grain boundary carbides were slightly observed, the difficulty in precipitation was indicated by “Δ”. When grain boundary carbides were not almost observed, the difficulty in precipitation was determined to be acceptable and indicated by “∘”.
[0174] The results thereof are as shown in Table 2. Comparative Steel 1 in which C and Cr are contained in large amounts is evaluated as “x”. Comparative Steel 3 in which the C content is high but the Cr content is as low as about 9% is evaluated as “Δ”, and the others are evaluated as “∘”. In Comparative Steel 1, precipitation of the grain boundary carbides becomes remarkable also in an actual mold production process, and there is a concern about deterioration of mirror polishing properties or cracking during use of the mold. Also in Comparative Steel 3, when the cooling rate after the hot working is further low or when the austenite grain size is further large, there is a concern that the grain boundary carbides are considerably precipitated.
[0175] On the other hand, for the other steels including Invention Steels, the grain boundary carbides are judged to be hardly precipitated also in actual molds. That is, a risk of deterioration in the mirror polishing properties or cracking is considered to be low.
[0000]
TABLE 2
Examination Items
Presence or Absence of
Presence or Absence
Precipitation of Grain
of Precipitation
Grain
Corrosion
Overall
Boundary Carbides
Annealability
of Pearlite
Size
Hardness
Resistance
Judgment
Invention Steel 1
∘
∘
∘
∘
∘
∘
∘
Invention Steel 2
∘
∘
∘
∘
∘
∘
∘
Invention Steel 3
∘
∘
∘
∘
∘
∘
∘
Invention Steel 4
∘
∘
∘
∘
∘
∘
∘
Invention Steel 5
∘
∘
∘
∘
∘
∘
∘
Invention Steel 6
∘
∘
∘
∘
∘
∘
∘
Invention Steel 7
∘
∘
∘
∘
∘
∘
∘
Invention Steel 8
∘
∘
∘
∘
∘
∘
∘
Invention Steel 9
∘
∘
∘
∘
∘
∘
∘
Invention Steel 10
∘
∘
∘
∘
∘
∘
∘
Invention Steel 11
∘
∘
∘
∘
∘
∘
∘
Invention Steel 12
∘
∘
∘
∘
∘
∘
∘
Invention Steel 13
∘
∘
∘
∘
∘
∘
∘
Invention Steel 14
∘
∘
∘
∘
∘
∘
∘
Invention Steel 15
∘
∘
∘
∘
∘
∘
∘
Comparative Steel 1
x
∘
x
∘
∘
∘
x
Comparative Steel 2
∘
∘
∘
x
x
∘
x
Comparative Steel 3
Δ
x
x
∘
∘
x
x
Comparative Steel 4
∘
∘
∘
x
x
∘
x
Comparative Steel 5
∘
x
∘
x
∘
∘
x
<Annealability>
[0176] Using the above-mentioned block of 15 mm×15 mm×25 mm as a test specimen, evaluation was performed by an experiment simulating an annealing process in a factory. The test specimen was heated at 860° C. (Comparative Steel 2, Comparative Steel 3 and Comparative Steel 4) or 915° C. (the other steels) and kept for 120 minutes. Thereafter, it was cooled to 650° C. at 15° C./Hr, followed by natural cooling. Then, the HRB hardness of the test specimen was measured, and it was confirmed whether or not softened to the hardness at which the machine work could be easily performed. When the hardness was 97 HRB or less, the annealability was determined to be acceptable and indicated by “∘”. When the hardness is more than 97 HRB, the annealability was determined to be unacceptable and indicated by “x”.
[0177] The results thereof are as shown in Table 2. Comparative Steel 3 and Comparative Steel 5 exceed 97 HRB in the hardness after the annealing, and are not sufficiently softened. They are therefore evaluated as “x”. In Comparative Steel 3, contribution of solid solution hardening was large because of its high Si content, and the hardness thereof was high even after the annealing. Comparative Steel 5 did not form the structure containing spherical carbides and ferrite, but formed bainite, because of it high Ni content and good annealability. Therefore, the hardness thereof was high.
[0178] For Comparative Steel 3 and Comparative Steel 5, also during the actual mold production, there is a high possibility of shortening the tool life in rough machining of the mold, or decreasing the machining efficiency.
[0179] In contrast, for the other steels including Invention Steels, the hardness after the annealing is 97 HRB or less. It is therefore considered that such problems do not occur.
<Difficulty in Precipitation of Pearlite>
[0180] A test specimen of 4 mm (diameter)×10 mm was heated at 1,030° C., and thereafter cooled to 100° C. at 10° C./min. After cooling, a metal structure was observed at 400 magnifications to confirm the presence or absence of precipitation of pearlite. When pearlite was not precipitated, the difficulty in precipitation was determined to be acceptable and indicated by “∘”, and when pearlite was precipitated even slightly, the difficulty in precipitation was determined to be unacceptable and indicated by “x”.
[0181] The results thereof are as shown in Table 2. Comparative Steel 1 and Comparative Steel 3 are evaluated as “x”. The quench-cooling rate in the inside of the mold is generally from 10 to 40° C./min in a temperature range of 550 to 850° C. at which pearlite is precipitated, and therefore, the precipitation of pearlite becomes unavoidable in the inside of the mold using Comparative Steel 1 or Comparative Steel 3 to increase a risk of breakage during use thereof as the mold.
[0182] On the other hand, for the other steels including Invention Steels, pearlite was not precipitated, and also in the case when the mold is actually quenched, it can be judged that precipitation of pearlite does not occur.
<Grain Size During Quenching>
[0183] In actual mold quenching, the mold is sometimes kept for a time as long as about 5 hours. The grain size of austenite under such conditions was examined. Using the above-mentioned block of 15 mm×15 mm×25 mm as a test specimen, it was kept at 1,030° C. for 5 hours, and thereafter rapidly cooled to produce martensite. This structure was corroded to develop prior austenite crystal grain boundaries, and the grain size number was evaluated. When the grain size number was 5 or more, the grain size was determined to be acceptable and indicated by “∘”, and when the grain size number was less than 5, the grain size was determined to be unacceptable and indicated by “x”.
[0184] The results thereof are as shown in Table 2. In Comparative Steel 2 and Comparative Steel 4 which contain C in small amounts, carbides for suppressing transfer of austenite crystal grain boundaries are also decreased. Therefore, the results thereof are evaluated as “x”. In Comparative Steel 5, since a γ memory effect was developed during the quenching because of its poor annealability, the result thereof is evaluated as “x”. In the case of Comparative Steel 2, Comparative Steel 4 and Comparative Steel 5, there is a concern that also in the actual mold quenching, the crystal grains are coarsened to cause easy cracking during use thereof as the mold.
[0185] On the other hand, for the other steels including Invention Steels, the results thereof are evaluated as “∘”, and it is considered that coarsening of the crystal grains does not occur.
<Quenching Tempering Hardness>
[0186] The test specimen (in which martensite was produced) used in evaluation of the “Grain Size during Quenching” described above was tempered at 470-520° C. for 2 hours. The maximum hardness obtained in this tempering temperature range was evaluated. In order to ensure the wear resistance, the quenching tempering hardness is preferably 45 HRC or more. When the hardness was 45 HRC or more, it was determined to be acceptable and indicated by “∘”, and when the hardness was less than 45 HRC, it was determined to be unacceptable and indicated by “x”.
[0187] The results thereof are as shown in Table 2. In Comparative Steel 2 and Comparative Steel 4, a hardness of 45 HRC or more was not obtained because of their low C content, but all the other steels had a hardness of 45 HRC or more. That is, for Invention Steels, a hardness of 45 HRC or more necessary for ensuring the wear resistance was obtained. Needless to say, it is also possible to decrease the hardness by adjusting tempering conditions.
<Corrosion Resistance>
[0188] The test specimen used for evaluation of the above-mentioned “Quenching Tempering Hardness” was diverted as a test specimen. The test specimen after measurement of the hardness was subjected to mirror polishing and exposed to an environment of a humidity of 98% and a temperature of 50° C. for 24 hours, followed by visual observation of a rusting situation. When a dot-like corroded part was not generated, the corrosion resistance was determined to be acceptable and indicated by “∘”, and when the corroded part was generated even in one place, the corrosion resistance was determined to be unacceptable and indicated by “x”. In all of the steels evaluated, whole surfaces thereof were not corroded under these conditions, and a difference occurred between generation of dot-like local corroded parts and no generation thereof, because of their high Cr content.
[0189] The results thereof are as shown in Table 2. In Comparative Steel 3, the corrosion resistance is poor, because of its high C content and low Cr content, and the results thereof are evaluated as “x”. The other Comparative Steels and Invention Steels have high corrosion resistance, because of their high Cr content.
<Overall Judgment>
[0190] To summarize the above examination results, in Comparative Steel 1, it can be judged that the grain boundary carbides or pearlite is easily precipitated particularly in the large mold, and there is a problem of increasing a risk of deterioration in the mirror polishing properties or cracking.
[0191] Comparative Steel 2, Comparative Steel 3 and Comparative Steel 4 have a difficulty in any one of basic performances such as high hardness and high corrosion resistance. The other defects include the grain size for Comparative Steel 2, the annealability and the precipitation of pearlite for Comparative Steel 3, and the grain size for Comparative Steel 4.
[0192] Comparative Steel 5 has difficulties in the annealability and the grain size during the quenching, and there is a concern that the tool life or productivity in the machine work may be decreased, or that the mold obtained may be easily cracked. As described above, each Comparative Steel has problems in at least two items.
[0193] In contrast, 15 kinds of Invention Steels have no problems in all items. Invention Steels have the difficulty in precipitation of the grain boundary carbides, the annealability, the difficulty in precipitation of pearlite and fineness of the crystal grains while ensuring the basic performances such as high hardness and high corrosion resistance. Accordingly, also in the actual mold, it can be expected to exert high mirror polishing properties and difficulty in cracking, in addition to high hardness and high corrosion resistance.
[0194] As described above, in the steel of the present invention, in order to suppress the precipitation of the grain boundary carbides or pearlite, it was performed to decrease the C content, decrease the Cr content, increase the Mn content, increase the Ni content and add Mo, based on SUS420J2 (C: 0.4%, Mn: 0.4%, Ni: 0.2%, Cr: 13%, Mo: 0.01% and N: 0.015%). Furthermore, in order to compensate for a decrease in the hardness due to a decrease in the C content, the N content was increased. The addition of Mo has also an effect of suppressing the precipitation of pearlite or ensuring the secondary hardening amount. The annealability which is the same as that of SUS420J2 was ensured by not excessively increasing the Mn, Ni and Mo contents, and the corrosion resistance which is the same as that of SUS420J2 was ensured by decreasing the C content, and not excessively decreasing the Cr content. In addition, the austenite crystal grain boundaries were pinned with the carbides during the quenching, and in order to maintain the fine crystal grains, V was added. This is for the purpose of compensating for a decrease in Cr-based carbides due to decreasing of the C and Cr contents during the quenching with V-based carbides. A part of V solid-soluted during the quenching exerts an effect of compensating for the hardness by the secondary hardening. By such measures, when the mold is produced, the steel of the present invention has the difficulty in precipitation of the grain boundary carbides, the good annealability and the difficulty in precipitation of pearlite, and when the steel has been formed into the mold, it has high hardness and excellent corrosion resistance, and the prior austenite crystal grains are kept fine. It is therefore suitably applied to the mold for molding plastic products.
[0195] While embodiments of the present invention have been described in detail above, it should be understood that they have been presented by way of example only.
[0196] For example, it is also effective that the steel of the present invention is subjected to surface shot blast, nitriding treatment, PVD treatment, CVD treatment, plating treatment or other surface modification treatment and then used.
[0197] Also, the steel of the present invention can be applied to a powder or a plate used for mold production by powder or plate laminate shaping, and it is also possible to be used in a bar-like shape for weld repair of a main body or parts of the mold. Thus, embodiments in which various changes are made without departing from the gist of the present invention are possible.
[0198] The present application is based on Japanese Patent Application No. 2016-048581 filed on Mar. 11, 2016 and Japanese Patent Application No. 2017-39355 filed on Mar. 2, 2017, the contents of which are incorporated herein by reference.
|
The present invention relates to a mold steel having a composition including, in terms of mass %: 0.220%≦C≦0.360%; 0.65%≦Si<1.05%; 0.43%≦Mn≦0.92%; 0.43%≦Ni≦0.92%; 0.67%≦0.5Mn+Ni≦1.30%; 10.50%≦Cr<12.50%; 0.05%≦Mo<0.50%; 0.002%≦V<0.50%; 0.001%≦N≦0.160%; and 0.300%≦C+N≦0.420%, with the remainder being Fe and unavoidable impurities.
| 2
|
BACKGROUND OF THE INVENTION
[0001] The present invention is related to an ultrasonic scanning method and an ultrasound diagnostic apparatus, more particularly to an ultrasonic scanning method and an ultrasound diagnostic apparatus, which allow automatic control of the start of an interval scan and automatic control of the interval period between interval scans without attempting a preliminary interval scan, with no additional burden on the operator.
[0002] The ultrasound diagnostic apparatus of the Prior Art requires an operator to set the interval period of time of the interval scan prior to injecting a contrast agent to the subject, then to instruct the start of an interval scan at an appropriate timing while observing the ultrasound image generated by a scan using a weak ultrasound so as not to dissipate the contrast agent, thereafter the apparatus performs an interval scan using a sufficiently intense ultrasound to dissipate the contrast agent at a predefined interval period of time.
[0003] It is possible, however, that the operator sets such a short interval that the contrast agent cannot be sufficiently recovered, or an excessively longer period of time than as required to sufficiently recover the contrast agent. There has therefore been proposed an automated setting of the appropriate interval period of time of the interval scans by transmitting several times a sufficiently intense ultrasound to dissipate the contrast agent while varying the interval between scans (e.g., see patent reference no. 1).
[heading-0004] [Patent Reference 1] JP-A-2002-177269 ([0004], [0017])
[0005] In the Prior Art, there has been a problem that the operator is required to continue to carefully watch the ultrasound image so as to instruct the start of an interval scan at a timing presumed to be the optimal, resulting in an additional burden on the operator. Also, there has been a problem that a preliminary interval scan is required to be attempted in order to automate the interval period of time of an appropriate interval scan.
SUMMARY OF THE INVENTION
[0006] The object of the present invention therefore is to provide an ultrasonic scanning method and an ultrasound diagnostic apparatus, which allow automatic control of the start of an interval scan, and automatic control of the interval period of time of an interval scan without need of a preliminary interval scan, without an additional burden on the operator.
[0007] In a first aspect, the present invention provides an ultrasonic scanning method characterized by controlling an interval scan using a sufficiently intense ultrasound to dissipate a contrast agent, based on a dispersion value or mean brightness value of pixels of an entire image or part thereof, obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent.
[0008] The dispersion value or mean brightness value of pixels of an entire image or part thereof, obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent, may increase along with the in-flow of the contrast agent into the imaging area, and may decrease along with the contrast agent flew out from the imaging area.
[0009] In the ultrasonic scanning method in accordance with the first aspect above, the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent will be controlled by monitoring the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short interval period of time using a weak ultrasound so as not to dissipate the contrast agent, according to the change of dispersion or brightness value. This allows automated control of the start of an interval scan or automated control of the interval period of time of an interval scan without need to attempt a preliminary interval scan.
[0010] In a second aspect, the present invention provides an ultrasonic scanning method according to the abovementioned arrangement, characterized by controlling the start of an interval scan using a sufficiently intense ultrasound to dissipate the contrast agent, based on the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short period of time by use of the weak ultrasound so as not to dissipate the contrast agent.
[0011] The ultrasonic scanning method in accordance with the above described second aspect, the start of an interval scan using a sufficiently intense ultrasound to dissipate the contrast agent can be controlled by monitoring the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short interval period of time using a weak ultrasound so as not to dissipate the contrast agent, for detecting the change in the dispersion or mean brightness value indicative of the in-flow of the contrast agent into the imaging area. This allows automatic control of the start of an interval scan without an additional burden on the operator.
[0012] In a third aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by computing the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent as a monitor value, for performing a first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent when a monitor value exceeds a starting monitor value.
[0013] In the ultrasonic scanning method in accordance with the third aspect, the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent can be started, by monitoring the dispersion or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short interval period of time using a weak ultrasound so as not to dissipate the contrast agent, for detecting the increase of the dispersion or mean brightness value in excess of a start monitoring value indicative of the in-flow of the contrast agent into the imaging area. This allows automatic start of an interval scan without an additional burden on the operator.
[0014] In a fourth aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by computing the starting monitor value by multiplying a coefficient value by the monitor value at the time of the instruction by an operator.
[0015] In the ultrasonic scanning method in accordance with the fourth aspect as described above, after the contrast agent is injected to the subject, upon an instruction of stand-by by an operator at an appropriate timing while watching the ultrasound image generated by the scan using a weak ultrasound so as not to dissipate the contrast agent to thereby perform an automatic configuration of the starting monitor value, an interval scan will be triggered when the dispersion value or mean brightness value exceeds the starting monitor value. As the change of monitor value at or around the timing of stand-by instruction is slower than the change of monitor value around the start timing of an interval scan, there will not be a problem if the instruction is given a little earlier or later. This allows an interval scan to start automatically without need to an additional burden on the operator.
[0016] In a fifth aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by allowing the operator to set the starting monitor value.
[0017] In the ultrasonic scanning method in accordance with the fifth aspect as described above, after setting the starting monitor value and injecting the contrast agent to the subject by an operator, an interval scan will be started when the dispersion value or mean brightness value exceeds the starting monitor value. This dispenses with the need of giving an instruction to start by the operator at the starting timing of interval scan while closely watching the ultrasound image generated by the scan using a weak ultrasound so as not to dissipate the contrast agent, resulting in an automated start of an interval scan without an additional burden on the operator.
[0018] In a sixth aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by controlling an interval between two interval scans using a sufficiently intense ultrasound to dissipate the contrast agent, based on the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent.
[0019] In the ultrasonic scanning method in accordance with the sixth aspect above, the interval period of time of an interval scan using a sufficiently intense ultrasound to dissipate the contrast agent is controlled by monitoring the dispersion value or mean brightness value of pixels of the entire image or part thereof obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent, and by detecting the velocity of in-flow of the contrast agent into the imaging area based on the dispersion or mean brightness value. This may eliminate the concern about the setting of such a short interval that the contrast agent cannot be sufficiently recovered or an excessively longer interval than as required to sufficiently recover the contrast agent. In addition, there is no need to attempt to perform a preliminary interval scan.
[0020] In a seventh aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by computing the dispersion value or mean brightness value of pixels of the entire image or part thereof, obtained by scanning for every short period of time by use of the weak ultrasound so as not to dissipate the contrast agent as a monitor value, for performing a scan using a sufficiently intense ultrasound to dissipate the contrast agent when the monitor value having decreased at a previous scan using a sufficiently intense ultrasound to dissipate contrast agent exceeds a trigger monitor value.
[0021] In the ultrasonic scanning method in accordance with the seventh aspect as described above, a scan using a sufficiently intense ultrasound to dissipate the contrast agent is performed by monitoring the dispersion value or mean brightness value of pixels of an entire image or part thereof obtained by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent, and by detecting the recover of the contrast agent by virtue of the increase of the dispersion or mean brightness value having once decreased at the previous scan using a sufficiently intense ultrasound to dissipate the contrast agent. This allows automated and appropriate control of the interval period of an interval scan.
[0022] In an eighth aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by allowing the operator to set the trigger monitor value.
[0023] In the ultrasonic scanning method in accordance with the eighth aspect, the interval period of time of an interval scan can be adjusted intentionally by an operator setting a triggering monitor value.
[0024] In a ninth aspect, the present invention provides an ultrasonic scanning method according to the above arrangement, characterized by performing a scan using a sufficiently intense ultrasound to dissipate the contrast agent when the monitor value having decreased at the previous scan using a sufficiently intense ultrasound to dissipate the contrast agent does not exceed the trigger monitor value after a predetermined waiting period has elapsed.
[0025] In the ultrasonic scanning method in accordance with the ninth aspect, the predetermined waiting period of time is the maximum value of the period of time of an interval scan. In other words, a scan using a sufficiently intense ultrasound to dissipate the contrast agent can be necessarily performed once for a predetermined waiting period.
[0026] In a tenth aspect, the present invention provides an ultrasound diagnostic apparatus, including an ultrasonic probe, ultrasonic scanning means for scanning inside a subject by means of the ultrasonic probe, ultrasonic imaging means for generating an ultrasonic image based on data obtained by the scan, monitor value obtaining means for computing the dispersion value or mean brightness value of an entire image or part thereof generated by scanning for every short period of time by use of a weak ultrasound so as not to dissipate the contrast agent, controlling means for controlling an interval scan using a sufficiently intense ultrasound to dissipate the contrast agent based on the computed monitor value, and ultrasonic image display means for displaying an ultrasonic image generated by the interval scan.
[0027] The ultrasound diagnostic apparatus in accordance with the tenth aspect as described above may allow the ultrasonic scanning method according to the first aspect above to be preferably effectuated.
[0028] In an eleventh aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, in which the controlling means control the start of an interval scan using a sufficiently intense ultrasound to dissipate contrast agent, based on the monitor value.
[0029] The ultrasound diagnostic apparatus in accordance with the eleventh aspect may allow the ultrasonic scanning method according to the second aspect to be preferably effectuated.
[0030] In a twelfth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, in which the controlling means performs a first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent when a monitor value exceeds a starting monitor value.
[0031] The ultrasound diagnostic apparatus in accordance with the twelfth aspect may allow the ultrasonic scanning method according to the third aspect to be preferably effectuated.
[0032] In a thirteenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, further comprising starting monitor value computing means for computing the starting monitor value by multiplying a coefficient value by the monitor value at the time of an instruction by an operator.
[0033] The ultrasound diagnostic apparatus in accordance with the thirteenth aspect as described above may allow the ultrasonic scanning method according to the fourth aspect to be preferably effectuated.
[0034] In a fourteenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, further comprising operating means for the operator to set the starting monitor value.
[0035] The ultrasound diagnostic apparatus in accordance with the fourteenth aspect may allow the ultrasonic scanning method according to the fifth aspect to be preferably effectuated.
[0036] In a fifteenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, characterized by the controlling means controlling an interval period between two interval scans using a sufficiently intense ultrasound to dissipate the contrast agent, based on the monitor value.
[0037] The ultrasound diagnostic apparatus in accordance with the fifteenth aspect may allow the ultrasonic scanning method according to the sixth aspect to be preferably effectuated.
[0038] In a sixteenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, characterized by the controlling means performing a scan using a sufficiently intense ultrasound to dissipate the contrast agent when the monitor value having decreased at a previous scan using a sufficiently intense ultrasound to dissipate the contrast agent exceeds a trigger monitor value.
[0039] The ultrasound diagnostic apparatus in accordance with the sixteenth aspect as described above may allow the ultrasonic scanning method according to the seventh aspect to be preferably effectuated.
[0040] In a seventeenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, further comprising operating means for the operator to set the trigger monitor value.
[0041] The ultrasound diagnostic apparatus in accordance with the seventeenth aspect as described above may allow the ultrasonic scanning method according to the eighth aspect to be preferably effectuated.
[0042] In an eighteenth aspect, the present invention provides an ultrasound diagnostic apparatus according to the above arrangement, characterized by the controlling means performing a scan using a sufficiently intense ultrasound to dissipate the contrast agent when the monitor value having decreased at the previous scan using a sufficiently intense ultrasound to dissipate the contrast agent does not exceed the trigger monitor value after a predetermined waiting period has elapsed.
[0043] The ultrasound diagnostic apparatus in accordance with the eighteenth aspect may allow the ultrasonic scanning method according to the ninth aspect to be preferably effectuated.
[0044] In accordance with the ultrasonic scanning method and ultrasound diagnostic apparatus of the present invention, the start timing and interval of the interval scan may be automatically controlled corresponding to the situation of imaging.
[0045] Namely, the ultrasonic scanning method and ultrasound diagnostic apparatus in accordance with the present invention may allow automatic control of the start of an interval scan without an additional burden on the operator or automatic control of the interval period of time of an interval scan without attempt to perform a preliminary interval.
[0046] Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 shows a schematic block diagram of an ultrasound diagnostic apparatus in accordance with the first preferred embodiment of the present invention;
[0048] FIG. 2 shows a schematic diagram illustrating the computing area of monitor value;
[0049] FIG. 3 shows a flowchart illustrating the protocol of an interval scan processing in the ultrasound diagnostic apparatus in accordance with the first preferred embodiment of the present invention;
[0050] FIG. 4 shows a schematic diagram illustrating the start timing and interval of interval scan in a situation in which the contrast agent rapidly flows in to the imaging area;
[0051] FIG. 5 shows a schematic diagram illustrating the interval period of interval scan in a situation in which the contrast agent hardly flows in to the imaging area.
DETAILED DESCRIPTION OF THE INVENTION
[0052] In the following, preferred embodiments in accordance with the present invention will be described with reference to the accompanying drawings.
[0053] FIG. 1 shows a schematic block diagram of an ultrasound diagnostic apparatus 100 in accordance with the first preferred embodiment of the present invention.
[0054] This ultrasound diagnostic apparatus 100 includes an ultrasonic probe 1 , a transceiver unit 2 for driving the ultrasonic probe 1 to scan a subject with the ultrasound to output received signals, a signal processing unit 3 for generating an ultrasonic image data based on the received signals, a DSC (Digital Scan Converter) 4 for generating display image data based on the ultrasonic image data, a display unit 5 for displaying an image based on the display image data, an operating console 6 for an operator to input an instruction, a monitor value computing unit 7 for computing a dispersion value or mean brightness value as a monitor value based on the ultrasonic image data, and a controller unit 8 for controlling the operation of the entire apparatus.
[0055] As shown in FIG. 2 , an operator can set a monitor value computing area A on a B mode image G prior to an interval scan processing. The entire B mode image G can be set as the monitor value computing area A.
[0056] FIG. 3 shows a flowchart illustrating the protocol of an interval scan processing in the ultrasound diagnostic apparatus 100 .
[0057] In parallel to the interval scan, it is assumed that the ultrasound diagnostic apparatus 100 generates sequentially B mode images (for example, a frame rate between 50 and 10) by scanning for every short period of time (for example, 20 ms to 100 ms) using a weak ultrasound so as not to dissipate the contrast agent, to compute a dispersion or mean brightness value of the monitor value computing area A in the latest B mode image as the monitor value.
[0058] In step K 1 , the operator can set either a starting monitor value and trigger monitor value, or set the computing method of the starting monitor value and trigger monitor value. The value or computing method of those starting monitor value and trigger monitor value may be identical or different. In this example a computing method is set such that “start monitor value=trigger monitor value is substituted with a value Vs=V×□, or the value that is the monitor value V multiplied by □ when the stand-by instruction is given by the operator”.
[0059] In step K 3 , the operator will set the maximum transmission interval Ts.
[0060] In step K 4 , the operator will inject the contrast agent to the subject.
[0061] In step K 5 , the controller unit 8 proceeds the process to step K 8 if the start monitor value and trigger monitor value is set, or proceeds the process to step K 6 if the computing method of start monitor value and trigger monitor value is set.
[0062] In step K 6 , the controller unit 8 will wait until a stand-by instruction is given by the operator, and will proceed to step K 6 when the stand-by instruction is given.
[0063] The operator will direct a stand-by instruction at an appropriate timing while watching the B mode image G by the weak ultrasound. In this example, the stand-by instruction assumes to be given at the time tb, as shown in FIG. 4 .
[0064] In step K 7 , the controller unit 8 will compute the starting monitor value and triggering monitor value Vs from the monitor value Vb at the time tb (or immediately thereafter), as shown in FIG. 4 .
[0065] In step K 8 , the controller unit 8 will proceed to step K 9 if the most current monitor value V is not equal to or more than the start monitor value Vs, otherwise proceed to step K 10 if equal to or more than the start monitor value Vs.
[0066] In step K 9 , the process will go back to step K 8 if the elapsed time T is not equal to or more than a waiting time Tw, otherwise proceed to step K 12 if equal to or more than the waiting time Tw.
[0067] At this point the elapsed time T is indicative of the elapsed time from the beginning of the interval scan process prior to the first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent, and is indicative of the elapsed time since the immediately preceding scan using a sufficiently intense ultrasound to dissipate the contrast agent when the first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent has been performed. The waiting time Tw is initially set to a sufficiently long time (for example, 60 seconds) prior to the first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent, and will be set to the maximum transmission interval Ts after the first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent will have been performed.
[0068] In step K 10 , the ultrasound diagnostic apparatus 100 will perform a scan using a sufficiently intense ultrasound to dissipate the contrast agent.
[0069] In step K 11 , the waiting time Tw will be set to the maximum transmission interval Ts. Then the process will return to step K 8 .
[0070] In step K 12 , the controller unit 8 will terminate the process if the operator indicates “terminate”, or will proceed to step K 10 if the operator does not indicate “terminate”.
[0071] FIG. 4 shows a situation in which the contrast agent flows rapidly in to the imaging area.
[0072] After instructing a stand-by, if the monitor value V exceeds the start monitor value Vs, first scan of the interval scan using a sufficiently intense ultrasound to dissipate the contrast agent will be performed. Then each time the monitor value, which has been decreased along with the dissipation of the contrast agent due to the intense ultrasound, is rapidly recovered beyond the trigger monitor value Vs, another scan using a sufficiently intense ultrasound to dissipate the contrast agent will be performed. Thus the interval time of the interval scan Ti will become shorter (for example, Ti=100 ms).
[0073] FIG. 5 shows a situation in which the contrast agent does not almost flow in to the imaging area.
[0074] Since the monitor value, which has been decreased by the dissipation of the contrast agent due to the intense ultrasound is not recovered beyond the triggering monitor value Vs after having elapsed the maximum transmission interval Ts, a scan using a sufficiently intense ultrasound to dissipate the contrast agent will be performed at almost every maximum transmission interval Ts (for example, Ts=2s).
[0075] Many widely different embodiments of the invention may be constructed without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
|
An ultrasonic system and method for automatic control of the start of an interval scan without a burden on an operator and automatic control of interval period in an interval scan without performing a preliminary interval scan, an interval scan will be controlled using a sufficiently intense ultrasound to dissipate a contrast agent, by monitoring a dispersion or mean brightness value of pixels in an entire image or part thereof obtained by scanning for every short period of time with a weak ultrasound so as not to dissipate the contrast agent.
| 0
|
FIELD OF THE INVENTION
This invention is directed to the construction of a secondary, lithium battery.
BACKGROUND OF THE INVENTION
Lithium ion or secondary lithium batteriers are known. See: Linden, D., Ed., Handbook of Batteries 2 nd Edition , McGraw Hill Inc., New York, N.Y. (1995), Chapter 36; and Besenhard, J. O. Ed., Handbook of Battery Material , Wiley-VCH Verlag GmbH, New York, N.Y. (1999). These batteries are the state of the art power sources for portable electronic devices, such as: laptop computers, cellular phones, and the like. While these batteries have enjoyed an excellent safety record, efforts to improve their safety continues.
The safety concern arises from the threat of, for example, cell rupture arising from a thermal runaway situation. The cell's components, electrolyte and lithium containing electrodes, are packaged in a sealed metal can. In thermal runaway, heat is generated within the cell that could raise the temperature of the electrolyte and lithium electrodes above their ignition temperature. See: Hatchard, T. D. et al, “Importance of Heat Transfer by Radiation in Li-ion Batteries during Thermal Abuse,” Electrochemical and Solid State Letters , vol. 3, no. 7, pages 305-308 (2000), incorporated herein by reference.
Thermal runaway may arise from several different situations, but those of concern here arise from “abuse” (or “thermal abuse”). Abuse is qualified by several standard tests including the “nail penetration” test, the “crush” test, and the “short circuit” test. See, for example, UL1642—Standard for Lithium Batteries (Underwriters Laboratories Inc., 1st Edition 10/1985 and 2nd Edition 11/1992); and “Guideline for Safety Evaluation on Secondary Lithium Cells,” Japan Storage Battery Association, Tokyo, Japan (1995), both are incorporated herein by reference. In the first two mentioned tests, the cell is physically damaged thereby bringing about contact of the anode and cathode (a short circuit) which leads to thermal runaway. In the latter test, the anode and cathode are externally electrically coupled (a short circuit) which leads to thermal runaway.
In the short circuited battery, a localized heat spot begins forming within the cell. This heat accelerates the chemical reactions (between anode and cathode via electrolyte) going on within the cell which creates an escalating heat producing situation (the heat production is also rapid, e.g. seconds) that should be avoided because of the potential adverse consequences. The potential adverse consequences and the importance of heat transfer out of a cell is known. See: Hatchard, Ibid . In Hatchard, a label on the exterior of the package (can) is used to improve the heat transfer from the can. The label is used to regulate the internal temperature of the can.
In a conventional secondary lithium cell (either cylindrical or prismatic), the microporous separator membrane between the anode and cathode is wrapped several times around the exterior of the wound anode, cathode, separator, prior to its insertion into the package (can). These additional wraps of the separator act as an insulator (thermal and electrical). The electrode comprises an electrode active mix and a current collector. The current collector for the negative electrode (anode) is a copper foil. The current collector for the positive electrode (cathode) is an aluminum foil. The cans are made of iron-based materials (e.g. steel) or aluminum. In a conventional cylindrical cell, for example, an 18650 (18 mm diameter and 65 mm long), the electrode closest to the interior surface of the can is the negative electrode (anode), having a copper foil current collector, the can body which is made of the iron-based material is the negative terminal of the battery, while the lid of the can is the positive terminal. In the conventional prismatic cell, two constructions are recognized. First, the negative electrode (i.e. copper current collector) is closest to the interior surface of the can (i.e. iron-based). Second, the positive electrode (i.e. aluminum current collector) is closest to the interior surface of the can (i.e. aluminum).
SUMMARY OF THE INVENTION
The instant invention is directed to a secondary lithium battery. The battery includes a negative electrode, a positive electrode, a separator sandwiched between the electrodes, an electrolyte impregnating the separator and being in a fluid communication with the electrodes, and a metal package adapted for containing the electrodes, the separator, and the electrolyte. One of the electrodes is in thermal contact with the package.
DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a cross-section view of a prior art cell.
FIG. 2 is a cross-sectional view of a cell made according to the present invention.
FIG. 3 is an exploded view of a cell made according to the present invention.
FIG. 4 is a graphical illustration of the performance (voltage and temperature) of a prior art cell and an inventive cell as a function of time.
DETAILED DESCRIPTION OF THE INVENTION
With regard to electrodes, electrolytes, and separators referred to herein, each is of conventional design or construction. Such information is known to the skilled artisan. For example, see: Linden, D., Ed., Handbook of Batteries 2 nd Edition , McGraw Hill Inc., New York, N.Y. (1995), Clip 36, and Besenhard, J. O., Ed., Handbook of Battery Materials , Wiley-VCH Verlag GmbH (1999), e.g., § 2.6, 2.7, and the like, both are incorporated herein by reference.
The instant invention is disclosed with reference to a cylindrical cell for convenience, but it is not so limited and may be applied to prismatic cells as well.
Referring to the drawings wherein like numerals indicate like elements as shown in FIG. 1, a prior art cell 10 comprising a can 12 being closed by lid 14 . A separator 16 is wrapped around a “jelly roll” and is in contact with the interior surface of can 12 . A seam 18 , created by overlapping the separator 16 upon itself as the battery is wound, is secured by a conventional piece of tape 20 .
In FIG. 2, the instant invention is illustrated. Cell 30 consists of a can 12 sealed with a lid 14 . The metal sheet 32 , typically a copper foil (i.e., the current collector) upon which the negative electrode material or electrode active mix (not shown, but conventional) has been spread in conventional manner, is in thermal contact (e.g., direct physical contact) with the interior surface of can 12 .
Referring to FIG. 3, the inventive cell 30 is illustrated in an exploded view. Jelly roll 36 is made in a conventional fashion with the exception that negative electrode 38 is longer than separator 40 or positive electrode 42 . Thus, when the jelly roll is completely wound, the copper current collector 32 of the negative electrode 38 is visible. This jelly roll 36 is inserted into can 12 , so that collector 32 of electrode 38 is in thermal contact with the interior surface of the can 12 . Tab 44 may be welded, in a known manner, to can 12 and thereby provides good electrical contact, just as tab 46 may be welded to lid 14 to provide good electrical contact. In a prismatic cell, a copper current collector would be in contact with the can or an aluminum current collector would be in contact with the can.
The current collector 32 is an excellent heat conductor, so that heat generated in the interior of the jelly roll 36 may be efficiently transferred to the exterior surface of the metal can 12 .
The improvement in heat transfer is best understood with reference to FIG. 4 . In FIG. 4, the performance (voltage and temperature) of the prior art cell and inventive cell is illustrated. The left-hand vertical axis indicates voltage (volts) as a function of time (seconds on the horizontal axis). The right-hand vertical axis illustrates temperature (centigrade) as a function of time (seconds on the horizontal axis).
The prior art cell's performance is illustrated with lines 50 , 52 and 54 . Line 50 illustrates the voltage as a function of time after the cell has suffered nail penetration (e.g., test method UL1642). Line 52 illustrates the temperature at the center of the jelly roll as a function of time. Line 54 illustrates the temperature at the exterior surface of the can as a function of time. Note, that as the voltage 50 drops, both temperature lines rise, but the interior temperature 52 rises more sharply in comparison to the exterior temperature 54 . The difference between lines 52 and 54 shows that heat does not dissipate well from the cell. Remember FIG. 1, where separator 16 , a plastic insulator, is in contact with can 12 .
The inventive cell's performance is illustrated with lines 60 , 62 , and 64 . Line 60 is the voltage, line 52 is the interior temperature, and line 64 , the exterior temperature. Note that the difference between lines 62 and 64 is smaller than the difference shown with the prior art cell. The small temperature difference of the inventive cell shows that heat is dissipated better from the cell when the current collector is in thermal contact with the can.
The present invention may be embodied into others specific forms without departing from the attributes thereof and, accordingly, reference should be made to the pending claims rather than to the foregoing specification as indicating the scope of the invention.
|
The instant invention is directed to a secondary lithium battery. The battery includes a negative electrode, a positive electrode, a separator sandwiched between the electrodes, an electrolyte impregnating the separator and being in a fluid communication with the electrodes, and a metal package adapted for containing the electrodes, the separator, and the electrolyte. One of the electrodes is in thermal contact with the package.
| 7
|
TECHNICAL FIELD
The present invention relates to flashlights and, more particularly, to a compact flashlight that may be coupled to various objects, such as a key ring, a book, or a hat, and that includes an improved switch configuration and a battery holder that allows for relatively easy battery installation and replacement.
BACKGROUND
A flat tire on a dark, lonely road. A blown fuse or tripped circuit breaker on a dark, stormy night. The desire to find a dropped object on the floor of a darkened theater. Many individuals have experienced one or more of these events. During these events, it many times seems inevitable that a flashlight is either unavailable or cannot be found. Moreover, if a flashlight is available or found, its batteries may be depleted. Thus, in recent years many manufacturers have developed and marketed compact flashlights that can be carried in, for example, a persons pocket or purse.
Many of the compact flashlights that are presently known include a light emitting diode (LED) that is powered from one or more small batteries. The LED and batteries are housed within a relatively small, compact housing that can easily fit in most pockets and/or purses. In addition, many presently known compact flashlights include a ring or other type of extension that allows the flashlight to be coupled to a key ring.
The presently known compact flashlights are convenient, safe, and relatively easy to use. Nonetheless, most suffer certain drawbacks. For example, while the rings and extensions allow for coupling to a key ring, most do not allow the flashlight to be coupled to other devices. Moreover, many of the rings and extensions do not include locks or other devices to inhibit accidental opening and detachment from the ring or extension. Furthermore, most compact flashlights presently do not include rotatable structures that allow the flashlight to be pointed in various directions, while resting on a surface.
In addition to the configurational drawback described above, it is noted that many of the present compact flashlights do not provide a convenient way to change the batteries. Indeed, if the batteries can be changed at all, in many instances this requires that the housing be disassembled and reassembled following battery replacement. This operation can be tedious, time confusing, difficult, and can also result in a loss of parts.
Yet another drawback of many presently known compact flashlights is the switches that are used to turn the LED on and off. In many cases, the switches are either permanent-type on/off switches, or momentary-type on/off switches. The permanent-type on/off switches are typically quite small, and can be difficult to operate. In addition, when the flashlights are assembled, precise positioning of the components within the housing, including the switch, is needed for proper operation. Thus, if the batteries are replaced, when the housing is reassembled the switch may fail, or may not operate properly upon reassembly of the housing.
Hence, there is a need for a compact flashlight that can be coupled to a key ring, as well as various other devices, and that includes a locking mechanism that inhibits accidental opening and detachment from the ring or extension, and/or is structurally configured to allow the flashlight to be pointed in numerous directions while resting on a surface, and/or allows for ease of battery replacement, and/or includes one or more switches that are easy to operate. The present invention addresses one or more of these needs.
BRIEF SUMMARY
The present invention provides a compact flashlight that can be coupled to a key ring, as well as various other devices, and that includes a locking mechanism that inhibits accidental opening and detachment. The compact flashlight is configured to allow the flashlight to be pointed in numerous directions while resting on a surface. The compact flashlight also provides for easy battery replacement, and includes a plurality of switches that are easy to operate.
In one embodiment, and by way of example only, a flashlight includes a housing assembly, a light, a battery holder, and a switch. The housing assembly has at least one aperture formed therein. The light is mounted at least partially within the housing assembly and extends at least partially through the housing assembly aperture. The battery holder is rotationally mounted on the housing assembly and is rotatable between at least an open position and a closed position. The first switch is disposed on the housing assembly and is configured to move between an activate position and a deactivate position, to thereby electrically energize and de-energize, respectively, the light when one or more batteries are installed in the battery holder.
In another exemplary embodiment, a flashlight includes a housing assembly, a light, a battery holder, a switch, and a clip. The housing assembly has at least one aperture formed therein. The light is mounted at least partially within the housing assembly and extends at least partially through the housing assembly aperture. The battery holder is disposed within the housing assembly and is adapted to receive one or more batteries therein. The switch is disposed on the housing assembly and is configured to move between at least an activate position and a deactivate position, to thereby electrically energize and de-energize, respectively, the light from the battery when one or more batteries are installed in the battery holder. The clip is rotationally coupled to the housing assembly and has at least a closed position and an open position. The clip includes a first jaw, a second jaw, and a spring. The first jaw has at least an inner surface and an outer surface. The second jaw is rotationally coupled to the first jaw and has at least an inner surface and an outer surface and is adapted to rotate relative to the first jaw. The spring is coupled between the first and second jaws and is configured to bias the clip toward the closed position, whereby at least a first portion of the first jaw inner surface engages at least a first portion of the second jaw inner surface.
In yet another exemplary embodiment, a flashlight includes a housing assembly, a light, a battery holder, a first switch, and a second switch. The housing assembly has at least one aperture formed therein. The light is mounted at least partially within the housing assembly and extends at least partially through the housing assembly aperture. The battery holder is disposed within the housing assembly and is adapted to receive one or more batteries therein. The first switch is movably disposed on the housing assembly and is configured to move between at least an activate position and a deactivate position, to thereby electrically energize and de-energize, respectively, the light from the battery when one or more batteries are installed in the battery holder. The second switch is movably disposed on the housing assembly and is configured to move between at least (i) an on position, in which the second switch engages the first switch and moves it to its activate position, and (ii) an off position, in which the second switch is disengaged from the first switch.
These and other features and advantages of the preferred flashlight will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a compact flashlight according to an exemplary embodiment of the present invention;
FIGS. 2 and 3 are a top and bottom views, respectively, of the compact flashlight shown in FIG. 1 ;
FIGS. 4 and 5 are sides views of the compact flashlight shown in FIG. 1 ;
FIGS. 6 and 7 are end views of the compact flashlight shown in FIG. 1 ;
FIGS. 8 and 9 are cross section views of the compact flashlight shown in FIG. 1 ;
FIG. 10 is a simplified schematic representation of a light circuit incorporated into the compact flashlight of the compact flashlight shown in FIG. 1 ;
FIGS. 11 and 12 are top and bottom views of the compact flashlight shown in FIG. 1 , with a battery holder in the open position;
FIG. 13 is a perspective view of a portion of the structure used to implement the battery holder;
FIG. 14 is a side view of the compact flashlight illustrating the rotation of the clip;
FIG. 15 is a side view of the compact flashlight depicting the clip in more detail;
FIG. 16 is a perspective view of the compact flashlight showing it being clipped to a keyring;
FIG. 17 is a perspective view of the compact flashlight showing it being clipped to a hat; and
FIG. 18 is a side view of the compact flashlight showing it resting on a surface and directed in a desired direction.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A perspective view of a particular preferred embodiment of a compact flashlight 100 is shown in FIG. 1 , and includes a housing assembly 102 , and a clip assembly 104 . The housing assembly 102 houses various components, many of which are described more fully below, and is preferably sized and dimensioned to fit within a conventional pant pocket, purse, or other relatively small carrying device. The clip assembly 104 is rotationally coupled to the housing assembly 102 and is used to couple the flashlight 100 to one or more devices. For example, as shown in FIG. 16 , the clip 104 may be used to couple the flashlight 100 to a keyring 1602 . The housing assembly 102 and the clip assembly 104 , and the components that make up each assembly, will now each be described in detail, beginning first with the housing assembly 102 .
Turning now to FIGS. 2–7 , which depict top, bottom, side, and end views of the flashlight 100 , in combination with FIG. 1 , it is seen that the housing assembly 102 includes an upper housing section 106 , and a lower housing section 108 . The upper 106 and lower 108 housing sections are coupled together by, for example, a plurality of fasteners 302 (see FIG. 3 ), though it will be appreciated that these sections could also be coupled together using other means such as, for example, an adhesive, or a snap-fit.
The upper 106 and lower 108 housing sections are configured such that when each are coupled together, the housing assembly 102 includes an aperture 110 formed in a first end 112 of the housing assembly 102 (see FIG. 1 ). With reference now to FIG. 8 , the upper 106 and lower 108 housing sections also preferably each include a mount collar 802 a, 802 b on respective inner surfaces 804 , 806 thereof A light 808 , which is preferably a light emitting diode (LED), is mounted within the housing assembly 102 and is supported within the housing via the mount collars 802 a, 802 b. The light 808 , when mounted within the housing assembly 102 , preferably extends only partially through the aperture 110 , and is thus recessed within the housing assembly 102 . This preferred configuration, in which the light 808 is recessed within the housing assembly 102 , helps protect the light 808 from external, potentially damaging hazards. It will be appreciated, of course, that this is merely exemplary a particular preferred configuration, and that the light 808 could extend beyond the perimeter of the housing assembly 102 .
With continued reference to FIG. 8 , and as was previously noted, it is seen that, in addition to the light 808 , various other components are housed within, and mounted on, the housing assembly 102 . These components include one or more batteries 810 , a pair of switch contacts 812 a, 812 b, a first switch 814 , and a second switch 816 . The batteries 810 , which in the depicted embodiment are two lithium coin-type batteries, are used to supply power to the light 808 when either of the switches 814 , 816 is activated. It will be appreciated that the type of battery used may vary, and that lithium coin-type batteries is merely exemplary of a particular preferred embodiment. No matter the particular type or number of batteries, and as will be described in more detail further below, the batteries 810 are preferably mounted in a rotatable battery compartment that allows ready access to, and removal and/or replacement of, the batteries 810 . As may be seen, when the light 808 and batteries 810 are properly mounted within the housing assembly 102 , the light 808 is electrically coupled in series between the batteries 810 and one of the switch contacts 812 a.
The switch contacts 812 a, 812 b are which are formed of any one of numerous electrically conductive materials such as, for example, nickel-plated phosphorus, bronze, nickel-plated steel, gold-plated steel, and brass, are mounted within the housing assembly 102 and include a fixed switch contact 812 a, and a movable switch contact 812 b. The fixed switch contact 812 a is preferably, though not necessarily, non-movable, and is configured to be electrically coupled to the batteries 810 when the batteries 810 are properly mounted and disposed within the housing assembly 102 . The movable switch contact 812 b, as the term used herein connotes, is selectively movable. In particular, the movable switch contact 812 b is selectively movable between a contact position and a non-contact position. In the non-contact position, which is the normal position, the movable switch contact 812 b is electrically isolated from the fixed switch contact 812 a. Conversely, in the contact position, the movable switch contact 812 b is electrically coupled to the fixed switch contact 812 a.
The movable switch contact 812 b may be configured in any one of numerous ways to implement the above-described functionality. However, in the depicted embodiment this is accomplished by coupling one end of the moveable switch contact 812 b to the first switch 814 and another end of the movable switch contact 812 b to the housing assembly 102 . The movable switch contact 812 b is also configured such that when it and the light 808 are properly disposed within the housing assembly 102 , the light 808 is electrically coupled to the movable switch contact 812 b.
With the above-described switch contact configuration, and as is shown more clearly in schematic form in FIG. 10 , the batteries 810 , the light 808 , and the switch contacts 812 a, 812 b form a series electrical circuit 1000 . Thus, when the movable switch contact 812 b is moved to the contact position, it is electrically coupled to the fixed switch contact 812 a, thereby closing the circuit 1000 and allowing the batteries 810 to supply current to the light 808 , which causes the light 808 to illuminate. As will now be described, the movable switch contact 812 b is moved between the contact and non-contact position by operation of either the first 814 or second 816 switches.
Returning once again to FIG. 8 , and with additional reference to FIGS. 1 and 2 , it was previously noted that the housing assembly 102 includes two switches, a first switch 814 , and a second switch 816 . The first switch 814 , which is referred to hereinafter as a momentary switch 814 , is coupled to the housing assembly upper section 106 in a cantilever fashion and is movable between a deactivate position and an activate position. The momentary switch 814 is configured to be self-biased toward the deactivate position and, in response to a small force, to move to the activate position. As was just noted, the momentary switch 814 is also coupled to the movable switch contact 812 b. When the momentary switch 814 is in the deactivate position, which is the position shown in FIG. 8 , the movable switch contact 812 b is in its non-contact position, and is electrically isolated from the fixed switch contact 812 a . Conversely, when the momentary switch 814 is in its activate position, it moves the movable switch contact 812 b to its contact position, electrically coupling the fixed 812 a and movable 812 b switch contacts together, closing the electrical circuit 1000 , and causing the light 808 to illuminate.
The second switch 816 , which is referred to hereinafter as the on-off switch 816 , is slidably disposed within the housing assembly upper section 106 . Similar to the momentary switch 814 , the on-off switch 816 is movable between two positions, an on position and an off position; however, unlike the momentary switch 814 , the on-off switch 816 is not biased toward either position. Rather, the on-off switch 816 is configured such that, once it is moved to either the on or off position, it will remain in that position until it is moved to the other position. In particular, and as will now be described, when the on-off switch is moved to the on position, it engages the momentary switch 814 and moves the momentary switch to its activate position, thereby illuminating the light 808 .
The on-off switch 816 and momentary switch 814 are shown in the off position and the deactivate position, respectively, in FIG. 8 . If it is desired to keep the light 808 energized for an extended period, or for any period of time for that matter, without having to continuously apply pressure manually to the momentary switch 814 , then the on-off switch is moved to the on position. When this occurs, as is shown most clearly in FIG. 9 , the on-off switch 816 engages the momentary switch 814 , moving it to the activate position. As was noted above, when the momentary switch 814 is in the activate position, it moves the movable switch contact 812 b into electrical contact with the fixed switch contact 812 a, which causes the light 808 to illuminate. As was also noted above, the on-off switch will remain in the on position until it is manually moved to the off position.
It was previously noted that the batteries 810 are preferably mounted in a rotatable battery compartment. Turning now to FIGS. 11 and 12 , and with reference to FIG. 1 as necessary, the battery holder will be described in more detail. As shown in FIGS. 11 and 12 the battery holder 1102 is rotationally mounted on the housing assembly 102 and is movable between an open position, which is shown in FIGS. 11 and 12 , and a closed position, which is shown in FIG. 1 . The battery holder 1102 may be rotationally mounted using any one of numerous types of devices, but in the depicted embodiment is rotationally mounted using a non-illustrated sleeve that surrounds one of the fasteners 302 . No matter the particular manner in which the battery holder 1102 is rotationally mounted, it is seen in FIGS. 1 , 11 , and 12 that when the battery holder 1102 is in the open position, it extends away from the housing assembly 102 , exposing the batteries 810 . Conversely, when the battery holder 1102 is in the closed position, the battery holder 1102 is disposed at least partially within the housing assembly 102 , such that the batteries 810 are enclosed therein. A more detailed description of the battery holder 1102 will now be provided.
In the depicted embodiment, the battery holder 1102 includes a pivot arm 1104 , and a battery mount structure 1106 . The pivot arm 1104 includes a first end 1108 , a second end 1110 , an outer surface 1112 , and an inner surface 1114 . The pivot arm first end 1108 is rotationally mounted to the housing assembly 102 . The pivot arm second end 1110 has a tab 1116 formed thereon that cooperates with the upper housing section 106 to hold the battery holder 1102 in the closed position. In particular, and as shown in FIG. 12 , the tab 1116 has a post 1202 formed on its underside that cooperates with a similarly configured post 1118 formed on the upper housing section 106 to hold the battery holder 1102 in the closed position in a snap-fit manner. The pivot arm outer surface 1112 is configured such that when the battery holder 1102 is in the closed position, as shown in FIG. 1 , the outer surface 1112 is substantially flush with the housing assembly 102 .
The battery mount structure 1106 extends from the pivot arm 1104 inner surface and, as was alluded to above, is disposed within the housing assembly 102 when the battery holder 1102 is in the closed position. The battery mount structure 1106 is used to hold one or more batteries 810 . To do so, as is shown most clearly in FIG. 13 , the battery mount structure 1106 includes a plurality of snap-fit posts 1302 that extend substantially perpendicularly therefrom. When the batteries 810 are disposed within the battery holder 1102 , the batteries 810 are held in place on the battery mount structure 1106 via the snap-fit posts 1302 , which are flexible enough to allow the batteries 810 to be easily installed, yet rigid enough to hold the batteries 810 in place once the batteries have been installed.
Returning once again to FIG. 1 , as was noted above, the flashlight 100 additionally includes the clip assembly 104 , which is rotationally mounted to the housing assembly 102 . The clip assembly 104 , as was previously noted, may be used to couple the flashlight 100 to one or more devices. Moreover, as will be explained further below, the clip assembly 104 may additionally be used to position the flashlight 100 on a surface and to point the light 808 in a desired direction. However, before describing each of these exemplary end-uses, a more detailed description of the structure of a particular preferred embodiment of the clip assembly 104 will first be provided. In doing so, reference should once again be made to FIGS. 1 , 8 , and 9 , as necessary.
With continued reference first to FIG. 1 , it is seen that the clip assembly 104 includes a clip 114 and a connection arm 116 . The clip 114 is rotationally coupled to the connection arm 116 , which is in turn rotationally coupled to the housing assembly 102 . It will be appreciated that the clip 114 and connection arm 116 may be rotationally coupled in any one of numerous ways. However, in the depicted embodiment, and as shown more clearly in FIGS. 8 and 9 , hinge pins 818 are used. The hinge pins 818 are configured such that the clip 114 and the connection arm 116 may rotate, each with one degree-of-freedom, relative to the connection arm 116 and the housing assembly 102 , respectively, as is shown in FIG. 14 . It will be appreciated that configuring the clip 114 and connection arm 116 to rotate as depicted and described herein is merely exemplary, and that either or both could be configured to rotate with multiple degrees-of-freedom.
With continued reference to FIG. 1 ,in combination with FIGS. 8 and 9 , it is seen that the clip 114 includes at least two jaws, an upper jaw 118 and a lower jaw 120 , and additionally includes a bias spring 820 (see FIG. 8 ). The upper 118 and lower 120 jaws are rotationally coupled to one another via, for example, another hinge pin 822 , and are configured to rotate relative to one another. More specifically, in the depicted embodiment, the lower jaw 120 is rotationally coupled to the upper jaw 118 , and is configured to rotate relative to the upper jaw 118 . The upper 118 and lower 120 jaws each include an inner surface 902 and 904 , respectively, and an outer surface 906 and 908 , respectively (see FIG. 9 ).
As may be readily appreciated, the clip 114 is movable between a closed position, which is shown in FIGS. 8 and 9 , and an open position, which is shown in FIG. 15 . In the closed position, the upper and lower jaw inner surfaces 902 , 904 , or at least portions thereof engage one another. In the depicted embodiment, the upper and lower jaw inner surfaces 902 , 904 each include a plurality of lands 1502 and grooves 1504 , one or more of which, as shown in FIG. 15 , mate with one another when the clip 114 is in the closed position. The depicted clip 114 is also configured such that the upper and lower jaw inner surfaces 902 , 904 each include a substantially semi-circular groove 910 , 912 . The grooves 910 , 912 are preferably located on the upper and lower jaw inner surfaces 902 , 904 so that when the clip 114 is in the closed position, as shown in FIGS. 8 and 9 , the grooves 910 , 912 form a substantially circular opening 914 through the clip 114 .
The bias spring 820 is coupled to the upper 118 and lower 120 jaws and is configured to bias the clip 114 toward the closed position. Thus, in order to move the clip 114 to the open position, the bias force supplied by the bias spring 820 must first be overcome by an externally applied force. Preferably, the bias spring 820 is configured such that the bias force it supplies may be readily overcome manually. That is, the force exerted by the thumb and forefinger, for example, of a typical person may overcome the bias force, and move the clip 114 to the open position. As may be appreciated, once the externally applied force is removed, the clip 114 will snap toward the closed position.
In some instances it may not be desirable for the clip 114 to be readily, or easily, moved from the closed to the open position. Thus, the clip 114 additionally includes a lock 122 . In the depicted embodiment, the lock 122 , which in the depicted embodiment is a metal ring, is rotationally coupled to the clip upper jaw 118 , and is movable between a locked position, shown in FIGS. 1–9 , and an unlocked position, which is shown in FIG. 15 . With continued reference to FIG. 15 , it is seen that a lock groove 1506 is formed in the upper jaw 118 , and is configured to releasably engage the lock 122 when in the locked position. The lock 122 is further configured to engage the lower jaw 120 , when in the locked position, to thereby prevent rotation of the lower jaw 120 relative to the upper jaw, and thus prevent moving the clip 114 to the open position.
It was previously noted that the clip assembly 104 may be used to couple the flashlight 100 to various devices, and or dispose the flashlight 100 on various surfaces. For example, and as shown in FIGS. 16–18 , respectively, the clip assembly 104 may be used to couple the flashlight 100 to a keyring 1602 , to clip the flashlight 100 to a hat 1702 , or to dispose the flashlight 100 on a surface 1802 and point the housing assembly 102 in a desired direction to thereby illuminate a desired object or area.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
|
A compact flashlight is configured such that it can be coupled to a key ring, as well as various other devices, and includes a locking mechanism that inhibits accidental opening and detachment from the ring or other device. The compact flashlight is further configured to allow the flashlight to be pointed in numerous directions while resting on a surface, and further allows for ease of battery replacement. The compact flashlight additionally includes a plurality of switches that are easy to operate, and includes both a momentary switch and an on-off switch.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and to apparatus for preparing a substitution liquid.
2. Description of the Related Art
The term "substitution liquid" is used to designate a liquid for injection into the vascular circuit of a patient suffering, for example, from severe burns or having lost large quantities of blood or else a patient subject to blood purification treatment by hemofiltration or by hemodiafiltration, prescribed after temporary or permanent loss of renal function.
The invention is particularly applicable to treatment of this type since the quantity of substitution liquid required during a hemofiltration or a hemodiafiltration session may be very large (with some patients, as much as 30 liters for a four-hour session).
A substitution liquid must be sterile and pyrogen-free, i.e. it must be free from any pathogen and from any substance that could give rise to a febrile reaction in the patient. In addition, it must be isotonic relative to blood, i.e. it must have the same electrolytic concentration as blood. The relative proportions of cations and anions resulting from the dissociation of the electrolytes in the substitution liquid are adjusted as a function of patient requirements, depending on whether the patient's electrolytic equilibrium needs to be maintained or to be re-established.
Finally, a substitution liquid must contain at least those blood electrolytes which play an essential role in the metabolism, i.e., when dissociated in the form of cations and anions: sodium, potassium, calcium, and magnesium as cations, and chlorides and bicarbonates as anions, with the bicarbonates being essential to perform the buffer agent function.
The characteristics of a substitution liquid as recalled above, namely its sterility, its pyrogen-free nature, its isotonia relative to blood, and its specific electrolytic composition, mean that preparing a substitution liquid is difficult and requires special precautions.
In hospitals, it is common practice to use substitution liquids of standard composition prepared industrially by specialized suppliers. These liquids suffer from the drawback of being expensive. In addition, when they contain bicarbonates, they present storage difficulties that are not fully resolved at present, due to a combination of two factors. The first of these factors is that bicarbonates are unstable and decompose spontaneously and continuously into carbon dioxide when they are not confined in gastight manner. The second of these factors is that the bags used for packaging the substitution liquids are generally gas permeable. As a result, if it is desirable to use a substitution liquid having a precise concentration of bicarbonate, then the liquid must be used very soon after it has been packaged, and this constitutes a constraint on the user.
U.S. Pat. No. 4,702,829 describes apparatus for preparing a substitution liquid specifically for use during hemodiafiltration treatment, which apparatus mitigates these drawbacks in part. In that patent, proposals are made to prepare a substitution liquid on the basis of a dialysis liquid manufactured in a dialysis liquid generator, with dialysis liquids generally having substantially the same composition as standard substitution liquids but being neither sterile nor pyrogen-free. The apparatus described in that patent comprises a branch on the dialysis circuit, which branch includes two sterile filters between which a circulation pump is disposed.
In addition to being unsuitable for responding to a very specific requirement, that apparatus suffers from the drawbacks inherent to using expensive filters that must be changed regularly and whose possible clogging must always be detected in time.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for preparing a substitution liquid which is not specific to a particular treatment, which is simple, and which is relatively cheap to implement.
Another object of the invention is to provide apparatus enabling the method to be implemented.
Another object of the invention is to provide such apparatus which is particularly adapted to treatment by hemodiafiltration.
According to the invention, these objects are achieved by a method for preparing a substitution liquid, the method being characterized in that it consists in causing a sterile and pyrogen-free first liquid and a second liquid to flow over opposite sides of a semipermeable membrane in an exchanger, said liquids containing at least some of the electrolytes of blood including at least one buffer agent or at least one precursor of a buffer agent, at least some of the electrolytes being at different concentrations in the two liquids upstream from the exchanger, the substitution liquid being constituted by the first liquid downstream from the exchanger.
This method has the advantage of enabling a first sterile and pyrogen-free liquid to be enriched with determined electrolytes in determined proportions and without risk of contamination by means of a second liquid that need be neither sterile nor pyrogen-free, with the first liquid advantageously being selected from standard solutions having simple electrolytic composition which are readily available and cheap.
According to a characteristic of the invention, the second liquid is used downstream from the exchanger as a dialysis liquid.
This disposition is particularly advantageous in hemodiafiltration treatment since it enables a substitution liquid and a dialysis liquid to be prepared simultaneously using common preparation means.
According to another characteristic of the invention, one of the liquids is heated upstream from the exchanger so that downstream from the exchanger the first liquid has a temperature which is close to that of the human body.
When the heated liquid is the second liquid, then the exchanger, which is provided primarily for ion transfer, is also used as a heat exchanger. This disposition is particularly advantageous when the source of the second liquid is a dialysis liquid generator, since such generators usually include means for heating the liquid.
The present invention also provides an apparatus for preparing a substitution liquid, the apparatus being characterized in that it comprises an exchanger comprising two chambers separated by a semipermeable membrane, a first chamber having an inlet connected to a source of a first liquid which is sterile and pyrogen-free, and an outlet for connection to a receptacle (a patient or a supply of extemporaneous liquid), a second chamber having an inlet connected to a source of a second liquid, and an outlet for optional connection to a dialyzer, said liquids containing at least some of the electrolytes of blood and including at least one buffer agent or precursor for a buffer agent, at least some of the electrolytes being at different concentrations in the two liquids upstream from the exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention appear from reading the following description made with reference to the accompanying drawings, in which:
FIG. 1 is a diagram of apparatus of the invention for preparing a substitution liquid; and
FIG. 2 is a diagram showing the combination of hemodiafiltration apparatus together with apparatus of the invention for preparing substitution liquid.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus shown in FIG. 1 for preparing substitution liquid comprises an exchanger 1 having first and second chambers 2 and 3 separated by a semipermeable membrane 4 and connected to a first circuit and to a second circuit for conveying respective flows of liquids whose natures are specified below.
The first circuit comprises two portions 5 and 6 situated respectively upstream and downstream from the exchanger 1 relative to the liquid flow direction through said first circuit. The upstream portion 5 of the first circuit comprises a supply 7 for a first liquid connected via a duct 8 to an inlet 9 of the first chamber 2 of the exchanger 1. A peristaltic pump 10 is disposed on this portion of the first circuit to cause the first liquid to flow from the supply 7 towards the exchanger 1, and to adjust its flow rate. A flow meter 11 is disposed downstream from the exchanger 1 for accurately measuring the flow rate of the liquid injected into a patient 12.
In a simplified variant of the apparatus of the invention, the first circuit does not include the pump 10, nor does it include a flow meter 11. Rather the flow of the first liquid is driven by gravity, due to the supply 7 being placed higher than the patient 12. The duct 8 is then provided with a valve for adjusting the flow rate of the first liquid.
The downstream portion 6 of the first circuit includes a duct 13 having one end connected to an outlet 14 of the first chamber 2 of the exchanger 1 and having a cannula at its other end for insertion into a vein of the patient 12. Where applicable, this second end may also be connected to an extemporaneous supply of substitution liquid. The duct 13 passes through a degassing chamber 28. As a safety measure, an antibacterial filter 15 may be placed in the duct 13 upstream from the degassing chamber 28.
A heater member 23 is disposed in the downstream portion 6 of the first circuit to raise the liquid injected into the patient 12 to a temperature close to 37° C. when the flow rate of this liquid is greater than about 1 liter/hour (beneath this flow rate, it is acceptable to inject a patient with liquid at ambient temperature).
The second circuit also comprises two portions 16 and 27 respectively situated upstream and downstream from the exchanger 1 relative to the direction of liquid flow in said second circuit. The upstream portion 16 of the second circuit comprises a supply 17 for a second liquid, connected via a duct 18 to an inlet 19 of the second chamber 3 of the exchanger 1. A peristaltic pump 20 is disposed on this second portion of the circuit to cause the second liquid to flow from the supply 17 towards the exchanger 1, and to adjust its flow rate.
In a simplified variant of the apparatus of the invention, no pump is provided in the upstream portion 16 of the second circuit and the second liquid is caused to flow under gravity, with the supply 17 being placed higher than the patient 12. The duct 18 is then provided with a valve to adjust the flow rate of the second liquid.
In a variant apparatus of the invention, the heater member 23 is no longer disposed in the downstream portion 6 of the first circuit, but in the upstream portion 16 of the second circuit, with the first liquid then being heated by the second liquid in the exchanger 1.
The downstream portion 27 of the second circuit includes a duct 21 having one end connected to an outlet 22 of the second chamber 3 of the exchanger 1, and having its other end opening out into a wastewater drain circuit.
As can be seen in FIG. 1, the upstream portions 5 and 16 and the downstream portions 6 and 27 of the first and second circuits are connected to the exchanger 1 so that the first and second liquids flow therethrough in the same direction. This disposition, which is not the most favorable disposition for interchange between the two liquids (which interchange is specified below), nevertheless has the advantage of the hydraulic pressure gradients on either side of the membrane having the same sign. As a result, even if the membrane 4 of the exchanger 1 is a high permeability membrane, the risk of the second liquid ultrafiltering into the first circuit is small.
To eliminate this risk, which is unacceptable given that the first liquid must not be polluted under any circumstances, a head loss device 29 is placed in the first circuit downstream from the exchanger 1 so as to maintain a permanent positive transmembrane pressure between the chamber 2 and the chamber 3 in the exchanger 1. This head loss device may be adjustable and may be controlled by a control unit 25 to maintain the transmembrane pressure substantially constant, with control being as a function of the pressures that exist in the first and second circuits respectively inside the exchanger 1.
The control unit 25 also serves to control the pump 10 as a function of a substitution liquid flow rate QL determined by the clinician and as a function of the measured flow rate of the first liquid as provided by the flow meter 11, with control ensuring that the flow rate of the substitution liquid actually injected into the patient 12 is substantially equal to QL, in spite of any ultrafiltration which may take place inside the exchanger 1 (which depends on the nature of the membrane 4). The control unit 25 also adjusts the amount of heating produced by the heater unit 23 as a function of the flow rate of the substitution liquid. Under certain conditions of use of this first apparatus, defined relative to the ratio of the flow rates through the exchanger 1 and by the characteristics of the exchanger 1 (nature and area of the membrane 4), it may also be advantageous to provide for the control unit 25 to adjust the flow rate of the pump 20 as a function of the flow rate of the pump 10, for example if the ion transfers inside the exchanger 1 are to be controlled accurately, as described below.
The operation of the apparatus described above is based on the principle whereby two liquids containing electrolytes at different concentrations exchange ions when they are put into contact via a semipermeable membrane, with each type of ion migrating by diffusion through the membrane from the side of the membrane where ion concentration is higher towards the side of the membrane where ion concentration is lower, and the exchange of ions continues until concentrations on both sides of the membrane are in equilibrium.
It is important to observe that depending on the respective flow rates of the first and second liquids through the exchanger 1 and depending on the characteristics of the exchanger 1 (the nature and the area of its membrane 4), the rate of ion transfer inside the exchanger, whose uniformity guarantees that a substitution liquid is prepared having a determined electrolytic concentration, depends to a varying extent on the ratio of the flow rates through the exchanger. Given the range of flow rates QL that are usually prescribed, it will be advantageous, within the bounds of possibility, to select an exchanger 1 and a second liquid flow rate in such a manner that the ion transfer rate is not influenced by or is little influenced by any variation in the flow rate of the first liquid. If this cannot be done, then the pump 20 is servo-controlled to the pump 10 so that the ratio of their respective flow rates remains substantially constant, in accordance with the disposition mentioned above.
In accordance with the invention, the first liquid is a sterile and pyrogen-free solution which preferably has an electrolytic composition that is simple. The second liquid is a solution which need be neither sterile nor pyrogen-free, and its electrolytic composition is determined as a function of the electrolytic composition of the first liquid, of the flow rates of the liquids through the first and second circuits, and of the specific requirements of the patient 12, in such a manner that the substitution liquid per se, i.e. the liquid which flows in the downstream portion 6 of the first circuit, constituted by the first liquid enriched with ions and optionally heated by the second liquid, has an electrolytic composition, an ion concentration, and a temperature all appropriate to the patient. In principle, a standard composition is used for the first liquid, thereby making it easy to obtain on the market. The second liquid whose preparation does not require special precautions and is within the competence of ordinary pharmacy within hospitals, is advantageously the result of diluting concentrated saline solutions or salts in the solid state in distilled water.
By way of example, the following three pairs of liquids may be used in apparatus of the invention:
EXAMPLE 1
The first liquid is a solution of sodium chloride at a concentration substantially equal to that in blood. The second liquid contains the principal elecrolytes of blood, i.e., dissociated in the form of cations and anions: sodium, potassium, calcium, and magnesium as cations; and chlorides and bicarbonates as anions, with the bicarbonates serving above all as a buffer agent (and below the term "bicarbonate" is used as being generic over all of the bicarbonates in question). Instead of having this particular buffer agent, the second liquid could contain precursors of the buffer agent, such as acetate or acetate plus lactate, which precursors are transformed into bicarbonate by the human body. If the second liquid contains bicarbonates, a sufficient quantity of acetic acid is added thereto to prevent the calcium and magnesium ions causing the bicarbonate ions to precipitate. The concentration of sodium ions and chloride ions in the second liquid is identical to that in the first liquid so that no significant diffusion of these ions takes place through the membrane 4.
With these two liquids, diffusion transfers through the exchanger take place essentially from the second liquid to the first liquid.
EXAMPLE 2
The first liquid is a solution of chlorides of sodium, calcium, and magnesium. The second liquid contains the main electrolytes of blood, including bicarbonate as a buffer agent, but not including calcium and magnesium ions, thereby avoiding the problem of undesirable precipitation of bicarbonate ions due to calcium ions and magnesium ions being present in the second liquid. Since the concentration of calcium and magnesium ions in the second liquid is zero, these ions diffuse through the exchanger from the first liquid into the second. In order to obtain a desired concentration of calcium and magnesium ions in the substitution liquid, it is therefore necessary to choose a first liquid in which the concentration of calcium and magnesium ions is greater than the desired concentration in order to compensate for losses by diffusion.
EXAMPLE 3
The first liquid is a solution of sodium bicarbonate. The second liquid contains the main electrolytes of blood other than bicarbonate. In similar manner to that observed in Example 2, since the concentration of bicarbonate ions in the second liquid is zero, these ions diffuse in the exchanger from the first liquid into the second. In order to obtain a desired concentration of bicarbonate in the substitution liquid, it is therefore necessary to select a first liquid in which the bicarbonate concentration is greater than the desired concentration in order to compensate for diffusion losses.
The above-described apparatus for preparing a substitution liquid operates as follows. Once the first and second liquids have been respectively selected and prepared, the supplies 7 and 17 and the exchanger 1 are installed on a support (not shown) of the apparatus. Similarly, the first and second circuits are installed connecting the upstream and downstream portions 5, 16, and 6, 27 of these circuits to the exchanger 1 and to the supplies 7 and 17. Before connecting the ducts 8 of the first circuit to the first liquid supply 7, the first circuit and the first chamber 2 of the exchanger 1 to which it is connected are washed with a liquid that is sterile and pyrogen-free, after which the first circuit and the chamber 2 are initially filled (i.e. are "primed") with the same liquid. Advantageously, the liquid used for washing and for priming is the first liquid.
Once the desired flow rate QL of substitution liquid has been entered into the control unit 25, it causes the pump 10 to operate in such a manner as to ensure that the flow rate through the pump 10 is substantially equal to QL. If the pump 20 is to be servo-controlled to the pump 10, then the control unit 25 also controls rotation of the pump 20 so that the exchange rates through the exchanger are substantially constant. Once the initial fill of liquid in the first circuit has been completely expelled by the first liquid, and once the second liquid has completely filled the second circuit and has begun to flow out through the duct 21, then the liquid which leaves via the cannula connected to the end of the first circuit is the desired substiution liquid. The cannula can then be inserted into a vein of the patient 12 and injection may begin. On the basis of the information provided by the flow meter 11, which the control unit 25 compares with the desired flow rate QL for the substitution liquid, the rate of rotation of the pump 10 is adjusted so that the real flow rate is equal to the desired flow rate. The control unit 25 also controls operation of the heater unit 23 and adjusts the amount of heating provided thereby as a function of QL.
FIG. 2 shows a second apparatus for preparing substitution liquid in association with hemodiafiltration apparatus. In this figure, the reference numerals used in FIG. 1 are used again to designate corresponding items of this second apparatus of the invention.
This apparatus for preparing substitution liquid differs from the preceding apparatus essentially in that the downstream portion 27 of the second circuit, instead of having its free end opening out into a wastewater disposal system, is connected to an inlet 30 of a first chamber 31 of a dialyzer 32 whose outlet 33 is connected to a conventional dialysis circuit (shown in part) which includes, in particular, a pump 34 for circulating the dialysis liquid. In the hemodiafiltration apparatus shown in FIG. 2, it is thus the liquid coming from the second liquid supply 17 which is used as the dialysis liquid after it has passed through the exchanger 1.
The second chamber 35 of the dialyzer 32 which is separated from the first chamber 31 by a semipermeable membrane 36 has an inlet 37 connected to an artery line 38 on which a blood circulation pump 39 is disposed, and an outlet 40 connected to a vein line 41 opening out in the degassing chamber 28.
In this second embodiment of apparatus for preparing substitution liquid as shown in FIG. 2, the second circuit does not include a pump for the second liquid, with the second liquid being caused to flow by the pump 34 of the hemodiafiltration apparatus.
The pumps 10 and 34 operate independently from each other. An advantageous characteristic of this apparatus lies in the fact that, given the flow rates generally used for the dialysis liquid and for the substitution liquid, there exist exchangers having characteristics such that any variation in the substitution liquid flow rate, even over a relatively wide range, does not have any influence on the ion transfer rate through the exchanger for a given flow rate of dialysis liquid.
In other words, starting from liquids having respective determined compositions upstream from the exchanger 1, and operating at a given dialysis liquid flow rate, the respective compositions of the liquids downstream from the exchanger 1 (dialysis liquid, substitution liquid) do not change significantly regardless of the flow rate selected for the substitution liquid over a fairly large given range of flow rates. For example, in an exchanger fitted with a membrane having an area of about 0,5 m 2 , of the type known under the trade name Cuprophan, and operating at a dialysis liquid flow rate substantially equal to 500 ml/min, substantially 100% equilibrium occurs between the liquids in the exchanger 1 providing the flow rate of the substitution liquid lies in a range running from about 0 to about 50 ml/min.
Compared with the apparatus described with reference to FIG. 1, this apparatus also has a variant in which the connections of the upstream and downstream portions 5, 16 and 6, 27 of the first and second circuits with the exchanger 1 are crossed, so that the liquids flow in counterflow through the chambers 2 and 3 of the exchanger 1, thereby enhancing ion transfers through the membrane 3. Although such a counterflow disposition theoretically increases the risk of backfiltering compared with the same-direction parallel-flow disposition shown in FIG. 1, other things remaining equal, the actual risk in the present case is low insofar as firstly the respective pressures in the blood circuit and in the dialysis circuit of a hemodiafiltration circuit are conventionally adjusted so that positive transmembrane pressure exists between the dialyzer chamber containing blood and the dialyzer chamber containing dialysis liquid, and secondly in the installation shown in FIG. 2, the pressure in the blood circuit and the pressure in the substitution liquid circuit are substantially equal, said circuit being in communication via the degassing chamber 28 so that here again, when the hemodiafiltration apparatus is in operation, positive transmembrane pressure exists between the chamber 2 containing the substitution liquid and the chamber 3 containing the dialysis liquid in the exchanger 1.
The compositions of the first and second liquids used to prepare the substitution liquid in this second apparatus are no different from those described above. In contrast, the concentrations of the electrolytes respectively contained therein are adjusted so that the liquid leaving the second chamber 3 of the exchanger 1 has the characteristics of a dialysis liquid. This adjustment of concentrations as a function of the transfer rate through the exchanger 1 for the purpose of producing both a substitution liquid and a dialysis liquid of determined composition and electrolyte concentration is achieved by applying conventional laws for ion transfers through the semipermeable membranes.
In this second apparatus for preparing a substitution liquid, the second liquid is advantageously prepared continuously and is heated in a dialysis liquid generator 42 which includes the heater member 23 and which forms a portion of the hemodiafiltration apparatus with which the apparatus of the invention is associated. In order to ensure that the liquid injected into the patient 12 and that the second liquid downstream from the exchanger 1 which is used as the dialysis liquid are both at about 37° C., the heater member 23 raises the second liquid to a temperature higher than 27° C. in order to enable it to heat the first liquid in the exchanger 1 and to compensate for heat losses that take place in the first and second circuits.
The operation of this apparatus does not differ significantly from that described above with reference to the apparatus shown in FIG. 1.
It should be observed that once the first liquid circuit is connected to the supply 7 and once this circuit has been connected to the blood circuit (ducts 38, 41, and chamber 35 of dialyzer 32) via the degassing chamber 28, the first liquid may be used as a washing liquid and as a priming liquid both for the first liquid circuit and for the blood circuit.
The present invention is not limited to the embodiments described above, and it may be subjected to modifications and to variants.
|
The invention is directed to an apparatus and method for transforming a sterile pyrogen-free liquid into a substitution liquid using an exchanger. The method includes the steps of flowing first and second liquids over opposite sides of a semipermeable membrane, the first liquid being sterile and pyrogen-free. Both liquids contain at least some electrolytes of blood including at least a buffer agent or a precursor of a buffer agent. At least some of the electrolytes have different concentrations in the two liquids. When purifying blood by hemodiafiltration, this method has the particular advantage that, rather than discarding the second liquid, it can be used for hemodiafiltration.
| 0
|
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor integrated circuit device, and more particularly to a package for a semiconductor element (or die) having a plurality of electrodes to be applied with substantially the same voltage.
A semiconductor integrated circuit device is assembled by mounting a semiconductor element in a package and wiring electrodes of the semiconductor element with lead terminals provided on the package and connected to external leads which are in turn attached to the package. The semiconductor element provides a large number of active elements such as transistors and diodes and passive elements such as resistors and capacitors within one semiconductor chip which are interconnected by a metal layer deposited thereon in accordance with the required circuit function.
Due on the increasing commercial demands to semiconductor integrated devices for additional functions and enhancement of signal processing capability, the number of active and passive elements formed in one semiconductor chip, (that is, the integration density) is being increased, resulting in the increase in size of the semiconductor chip. Further, in order to operate at a high speed of signal processing, the amplitude of the signals processed by the integrated circuit device is lowered. In other words, a noise margin is reduced.
The increase in integration density or in size of the semiconductor chip enlarges the length of wiring layer and causes a potential shift of an actuating voltage such as a power supply voltage or the ground potential. Such a potential shift may cause a mulfunction of the circuit. In more detail, the integrated circuit device receives the power voltage along with the signals to be processed to actuate the active and/or passive circuit elements. The power voltage is generally supplied to one electrode of the semiconductor chip through one external lead provided on the package. This electrode is connected to the circuit elements requiring the power voltage via a wiring layer deposited on the semiconductor chip. The increase in the integration density increases the number of wirings for interconnecting circuit elements. That is, the wiring density is increased. Consequently, the wiring layer for connecting the electrode on the chip for receiving the power voltage (hereinafter called "power voltage electrode") to the circuit elements is compelled to become narrow and thin. In addition, the increase in size of the semiconductor chip elongates the length of the wiring layer, resulting in increase of the impedance of the wiring layer. As a result, a voltage different from that at the power voltage electrode is actually supplied to the circuit elements. In other words, the potential shift occurs. This potential shift causes a malfunction of circuit because the noise margin is small for the purpose of high processing speed. The same phenomena sometimes occur in the wiring layer for ground potential.
The aforementioned potential shift can be suppressed by providing a plurality of power voltage electrodes on the semiconductor chip. For instance, four power voltage electrodes are provided on the respective four edges of the semiconductor chip of a rectangular shape. In this manner, the circuit elements can receive the power voltage from the nearest power voltage electrode depending upon the disposed positions of the respective elements within the semiconductor chip. Accordingly, the lengths of the wiring layers connecting the power voltage electrodes to the circuit elements are shortened, resulting in the decrease in impedances of the wiring layers.
However, the formation of a plurality of the power voltage electrodes causes the increase in number of external leads. For instance, the provision of four power voltage electrodes necessitates four external leads. In other words, three extra external leads may additionally be required as compared to the conventional devices. An increase in number of the external leads enlarges the package, resulting in an expensive device. If the integrated circuit chip having a plurality of power voltage electrodes is mounted within a package whose external leads are predetermined in number, the number of external lead terminals for receiving signals to be processed and for deriving processed signals is reduced. Consequently, it is actually impossible to increase the integration density and/or the number of functions.
SUMMARY OF THE INVENTION
It is, therefore, one object of the present invention to provide a semiconductor integrated circuit device providing a package suitable for a semiconductor element having a plurality of electrodes to be applied with the substantially same voltage.
Another object of the present invention is to provide a semiconductor integrated circuit device, in which the substantially same voltage is supplied to a plurality of electrodes of a semiconductor element through one or more external leads, the number of which is less than the number of electrodes.
A semiconductor integrated circuit device according to the present invention comprises a package including a stem body having a central portion on one surface. An annular conductive layer is formed on the stem body and surrounds the central portion. At least one first external leads is formed on the stem body and electrically connected to the annular conductive layer and a plurality of second external leads are electrically isolated from the annular conductive layer. A semiconductor element having a first group of electrodes and a second group of electrodes is mounted on the central portion of the stem body. First connection paths electrically connect the first group of electrodes of the semiconductor element to the annular conductive layer, and second connection paths electrically connect each of the electrodes in the second group of electrodes of the semiconductor element to each of the second external leads. The number of electrodes in the first group connected to the annular conductive layer is greater than the number of first external leads.
The semiconductor element provides a plurality of electrodes electrically connected to the annular conductive layer to suppress the aforementioned potential shift, and therefore, it is preferable to supply the actuating voltage such as the ground potential or the power supply voltage thereto. The annular conductive layer is electrically connected to the first external lead, the number of which is smaller than that of the electrodes connected to the annular conductive layer. Accordingly, the annular conductive layer takes a voltage substantially equal to that supplied to the first external lead. As a result, the voltage of the annular conductive layer is supplied through the first connection paths to the plurality of electrodes of the semiconductor elements. Thus, by providing the annular conductive layer, a plurality of electrodes of the semiconductor element are supplied with the substantially same voltage, respectively, through one external lead or leads which are less in number than the electrodes.
It is preferable to use a package formed by integrally combining a plurality of insulative sheets as a package for the semiconductor integrated circuit device according to the present invention. In such a package, at least one conductive layer can be formed on the respective insulative sheets, so that a plurality of conductive layers separated from one another are formed in the package. Therefore, the package having the annular conductive layer electrically connected to the first external lead and electrically insulated from the second external leads can be easily manufactured without any short-circuit. Moreover, two or more annular conductive layers electrically insulated from each other can be formed in the package of this type. Therefore, two or more actuating voltages can be supplied to two or more annular conductive layers, respectively. In other words, the potential shifts of all the acutuating voltages are suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will become more apparent by reference to the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an internal perspective view showing a first preferred embodiment of the present invention;
FIG. 2 is an internal perspective view showing a second preferred embodiment of the present invention;
FIG. 3 is a cross-sectional view showing a third preferred embodiment of the present invention;
FIG. 4A is a plan view of a fourth preferred embodiment of the present invention with a cap removed, and
FIG. 4B is a cross-sectional view taken along a line A--A' in FIG. 4(A); and
FIG. 5A is a partial cross-sectional view showing a first example of modification of the fourth preferred embodiment shown in FIGS. 4A and 4B, and FIG. 5B is a partial cross-sectional view of a second example of modification of the same.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first preferred embodiment of the present invention will be described with reference to FIG. 1. The illustrated semiconductor integrated circuit device 100 is assembled by mounting a semiconductor element 1 in a package 30 provided with a plurality of external leads 25-1, 25-2, . . . 25-5 and a hermetically sealing metal lid 70. Thus, the semiconductor element 1 is separated from an external atmosphere.
The semiconductor element or chip 1 has a rectangular semiconductor body of, for example, silicon, and a large number of active and passive elements (not shown) formed therein. In order to supply signals to be processed to the chip 1 and to derive processed signals from the chip 1, there are provided a large number of electrodes 2. Furthermore, the chip 1 has electrodes supplied with a power supply voltage (hereinafter called "power supply electrode") for activating the respective circuit elements formed therein. At least one power supply electrode is provided along each of four edges of the chip 1 in order to suppress the aforementioned potential shift. In this embodiment, four power supply electrodes 2-1 to 2-4 are provided. It is to be noted that the power supply electrode 2-4 is not shown because of the partly cut away illustration.
The package 30 has a ceramic base 10 formed by superposing four unsintered alumina ceramic sheets 10-1 to 10-4 and integrally combining them through sintering. On the first ceramic sheet 10-1 is formed a tungsten metallized layer 12 called "island layer". The metallized layer 12 has an approximately rectangular shape of 7.6 mm×8.0 mm which is larger than the area of the semiconductor chip 1. The width, length and thickness of the sheet 10-1 are 15.1 mm, 60.1 mm and 1 mm, respectively. The semiconductor chip 1 is mounted on the layer 12 with brazing material 14 such as a gold-silicon eutectic alloy so that their centers may substantially coincide with each other. Alternatively, a gold layer is formed on the island 12 by plating, and thereafter the chip 1 is mounted on the layer 14 by annealing to produce a gold-silicon eutectic alloy layer 14 between the chip 1 and the gold layer. The second ceramic sheet 10-2 has a hole 15 of 8.4 mm×8.4 mm in size and the thickness of 0.64 mm. The third and fourth ceramic sheets 10-3 and 10-4 also have a hole 18 of 10.4 mm×10.4 mm in size and a hole 26 of 12.0 mm×12.0 mm in size, respectively. The thicknesses of the third and fourth sheets 10-3 and 10-4 are 0.3 mm and 0.5 mm, respectively. The centers of the respective holes 15, 18 and 26 and the center of the island 12 substantially coincide with one another. The width and length of the respective sheets 10-2 to 10-4 are equal to those of the sheet 10-1.
The ceramic sheet 10-2 provides a large number of connection terminals 16 on its surface exposed by the hole 18. Among the connection terminals 16, is included four connection terminals 16-1 to 16-4 which are connected to the power supply electrodes 2-1 to 2-4 via bonding wires 13-1 to 13-4 made of gold or aluminium. Here, the wire 13-4 and the terminal 16-4 are omitted from illustration. The other connection terminals 16 are also connected to the electrodes 2 via bonding wires 13. The respective connection terminals 16 are made of a metallized layer of tungsten. The connection terminal 16-1 connected to the power supply electrode 2-1 is led out to the outside of the base 10 through an internal wiring layer 17-1 formed between the sheets 10-2 and 10-3. However, as will be apparent from FIG. 1, other connection terminals 16-2 to 16-4 connected to the other power supply electrodes 2-2 to 2-4 are not directly led out, but are led out through an annular conductive layer 19 which will be explained thereafter. The remaining connection terminals 16 connected to the electrodes 2 other than the power supply electrodes 2-1 to 2-4 are lead out to the outside of the base 10 through other internal wiring layers 17, respectively. However, FIG. 1 shows only the internal wiring layer 17-1 extending from the connection terminal 16-1 and a part of another internal wiring layer 17-2 extending from another connection terminal 16 other than the terminals 16-2 to 16-4. The respective internal wiring layers 17 are also made of metallized layers of tungsten and formed simultaneously with formation of the connection terminals 16.
The ceramic sheet 10-3 is provided with the aforementioned annular conductive layer 19 on its surface portion exposed by the hole 26 and opposite to its contacting surface with the sheet 10-2. This annular conductive layer 19 is also formed as a metallized layer of tungsten. On the side surface of the sheet 10-3 formed by the hole 18, three tungsten metallized layers 20-1 to 20-3 are selectively formed. Here, the metallized layer 20-3 is not shown because it is formed on the side surface opposite to that on which the layer 20-1 is formed. These metallized layer 20-1 to 20-3 are extended from the annular conductive layer 19 to the connection terminals 16-2 to 16-4 to attain the electrical connection therebetween, respectively. This annular conductive layer 19 is further connected via a through-hole 22 provided in the sheet 10-3 to the internal wiring layer 17-1 leading out from the connection terminal 16-1 to the outside. Accordingly, the connection terminals 16-2, 16-3 and 16-4 connected to the power supply electrodes 2-2, 2-3 and 2-4 are led out to the outside of the base 10 through the annular conductive layer 19 and the internal wiring layer 17-1. The internal wiring layer 17-1 is connected to a tungsten metallized layer 23-1 formed on the side of the ceramic base 10. The metallized layer 23-1 is extended to a part of the bottom surface of the base 10. Other internal wiring layers 17 (containing the layer 17-2) are also respectively connected to tungsten metallized layers 23 (three layers 23-2 to 23-4 along with the layer 23-1 being shown) which are formed from the side of the ceramic base 10 to its buttom surface. External leads 25 (five leads 25-1 to 25-5 being shown) are connected to the metallized layers 23 by brazing material 24 such as a silver-copper eutectic alloy or a tin-lead alloy solder.
A power supply voltage to the integrated circuit device 100 is supplied to the external lead 25-1. The lead 25-1 is electrically connected to the power supply electrode 2-1 via the internal wiring layer 17-1, the connection terminal 16-1 and the bonding wire 13-1. The lead 25-1 is further connected to the other power supply electrodes 2-2 to 2-4 via the through-hole 22, the annular conductive layer 19, the metallized layer 20-1 to 20-3, the connection terminals 16-2 to 16-4 and the bonding wires3-2 to 3-4. Therefore, the power supply voltage applied to one external lead 25-1 is supplied to four electrodes 2-1 to 2-4 of the semiconductor chip 1, respectively. In other words, a plurality of electrodes of the semiconductor chip 1 is supplied with the substantially same voltage through one external lead 25-1.
The annular conductive layer 19 surrounds the semiconductor chip 1. Accordingly, even if the position of the respective power supply electrodes or the number of the power supply electrodes is changed, the annuar conductive layer 19 and the respective power supply electrodes are electrically connected with each other without any electrical short circuit to other electrodes. The annular conductive layer 19 is formed on the third ceramic sheet 10-3, and the connection terminals 16 and the internal wiring layers 17 are formed on the second ceramic sheet 10-2. Hence, there is no interference between the configurations of the conductive layers on the sheets 10-2 and 10-3.
The connection terminals 16-2 to 16-4 (the terminal 16-4 being not shown) may be connected to the annular conductive layer 19 by the bonding wires in place of the metallized layers 20. It is also possible to connect the connection terminals 16-2 to 16-4 to the annular conductive layer 19 via through-holes, respectively. The connection terminal 16-2 and the annular conductive layer 19 may be connected with each other via a metallized layer formed on the side surface of the sheet 10-3 or a bonding wire in place of the through-hole 22. The voltage drops between the terminals 16-1 to 16-4 and the electrodes 2-1 to 2-4 caused by the impedance of the bonding wires 13 are decreased by using two or more bonding wires, respectively. When there is a margin in the number of external lead terminals, two external lead wires could be connected to the annular conductive layer 19.
The fourth ceramic sheet 10-4 has a tungsten metallized layer 27 on its surface opposite to the sheet 10-3. A seal ring 29 made of an alloy of Fe, Ni and Co is connected to the metallized layer 27 by a silver-copper eutectic brazing material 28. The hermetic seal is effected between the seal ring 29 and the metal lid 70, and thereby the semiconductor chip 1 can be shielded from the external atmosphere.
The semiconductor integrated circuit device 100 shown in FIG. 1 is formed in the following way. At first, four unsintered alumina ceramic sheets 10-1 to 10-4 are prepared. The first sheet 10-1 is subjected to the tungsten metallization to form the island layer 12. The tungsten metallization is effected by selectively printing with ink containing tungsten. The thickness of the metallized layer is 20 to 30 μm. After making the hole 15 or before doing it in the second sheet 10-2, the tungsten metallization is attained to form the connection terminals 16 and the internal wiring layers 17 on the sheet 10-2, respectively. In the process of preparation of the third sheet 10-3, a small hole for the through-hole 22 and three large holes for the side surface metallized layers 20 are picked in the sheet 10-3, and the tungsten powder is then packed in the small hole. Next, the annular conductive layer 19 is formed by the tungsten metallization, and simultaneously, the tungsten ink is poured into the respective large holes. Thereafter, stamping of the hole 18 is effected. After the hole 26 is made in the fourth sheet 10-4, the tungsten metallized layer 27 is formed. The layer 27 may be formed before making the hole 26. The unsintered alumina ceramic sheets 10-1 to 10-4 processed in the above-described manner are registered and stacked with each other. Thereafter, the respective metallized layers 23 extending from the side surface of the base 10 to a part of the bottom surface are formed to make contact with the respective wiring layers 17. Subsequently, the heat treatment is carried out at 1500° C. to 1600° C. for about ten hours to sinter the respective ceramic sheets 10-1 to 10-4. Consequently, the ceramic base 10 having predetermined metallized conductor layers is formed.
In order to connect the respective external leads 25 and the seal ring 29, the nickel plating is effected at least on the metallized layers 23 and 27. The external leads 25 and the seal ring 29 are then bonded to the metallized layers 23 and 27 by means of silver-copper eutectic alloy material 24 and 28, respectively. The temperature upon this brazing is about 850° C. For the purpose of, for example, the prevention of oxidation, a nickel layer (2 to 4 μm) and a gold layer (2 μm) are plated on all the exposed conductor surfaces.
Thereafter, the semiconductor element 1 is mounted on the island layer 12 in the above-mentioned manner, and the respective electrodes 2 of the chip 1 are connected to the connection terminals 16 by bonding wires 13, respectively. The method of bonding could be either thermocompression bonding or supersonic bonding. Finally, the metal lid 70 is placed on the seal ring 29 and the hermetic seal therebetween is completed.
In place of the metal lid 70, a ceramic cap could be employed. In this case, the ceramic cap is bonded on the fourth sheet 10-4 by low melting point glass, for instance, solder glass having a 380° C. melting point. Alternatively, the lid 70 may be bonded on the metallized layer 27 by low melting point solder, for example, gold-tin eutectic alloy.
The integrated circuit device 100 illustrated in FIG. 1 has one annular conductive layer (i.e. the layer 19). In semiconductor integrated circuit devices, it is often required to suppress not only the potential shift of the power supply voltage but also that of the ground potential. A semiconductor integrated circuit device which satisfies this requirement is illustrated in FIG. 2. In FIG. 2, the same constituents as those shown in FIG. 1 are denoted by like reference numerals to omit further explanations thereof.
The semiconductor chip 1 shown in FIG. 2 further has four electrodes 2-5 to 2-8 supplied with the ground potential (hereinafter called "ground electrode"). On the other hand, one external lead 25-6 is provided for supplying the ground potential. In order to apply the ground potential from one external lead 25-6 to four ground electrodes 2-5 to 2-8, a second annular conductive layer 40 is provided. This annular conductive layer 40 is formed on the first ceramic sheet 10-1 simultaneously with the formation of the island layer 12 by the tungsten metallization, and it surrounds the perpheries of the semiconductor chip 1 and the island layer 12. Accordingly, the second annular conductive layer 40 is isolated from the first annular conductor layer 19 by the second and third sheets 10-2 and 10-3.
Four ground electrodes 2-5 to 2-8 of the semiconductor chip 1 are connected to four connection terminals 16-5 to 16-8 through bonding wires 13-5 to 13-8, respectively. These connection terminals 16-5 to 16-8 are formed on the second sheet 10-2 simultaneously with the other connection terminals 16. The bonding wire 13-8 and the connection terminal 16-8 are not shown in FIG. 2 because of the partly cut away illustration. The annular conductive layer 40 has four projected portions 40-1 to 40-4 in order to obtain the electrical connections to the connection terminals 16-5 to 16-8. The projected portions 40-1 to 40-4 and the connection terminals 16-5 to 16-8 are connected with each other through four metallized layers 42-1 to 42-4 not (the layer 42-4 being shown), respectively. The metallized layers 42-1 to 42-4 are formed on the side surface of the sheet 10-2. The through-holes may be used to connect the annular conductive layer 40 and the connection terminals 16-5 to 16-8. Accordingly, the connection terminals 16-5 to 16-8 are supplied with a potential substantially equal to that supplied to the second annular conductive layer 40, respectively.
Among four ground connection terminals 16-5 to 16-8, only one ground connection terminal 16-7 is directly led out to the outside of the base 10 through an internal wiring layer 17-3 which is formed simultaneously with the other internal wiring layers 17. The internal wiring layer 17-3 is connected to the side surface metallized layer 23-6 of the base 10, to which a grounding external lead 25-6 is connected by silver-copper eutectic brazing material 24. Consequently, the ground potential is applied to all of the four ground electrodes 2-5 to 2-8 by grounding the external lead 25-6. In other words, the substantially same potential is applied to a plurality of electrodes of the semiconductor chip 1 through one external lead, respectively.
The power supply electrodes 2-1 to 2-4 of the semiconductor chip 1 are applied with the power supply voltage from one external lead 25-1 through the first annular conductor layer 19, respectively. It is to be noted that the connection terminal 16-1 is connected to the annular conductive layer 19 by a side surface metallized layer 44 in place of the through-hole 22 in FIG. 1.
Also in the second preferred embodiment shown in FIG. 2, modifications similar to those described in connection to the first preferred embodiment in FIG. 1 are possible. The semiconductor chip often requires the power supply voltage or the ground potential in order to bias its semiconductor body. In this case, it is preferable to supply a bias voltage to the semiconductor body of the chip 1 from the island layer 12. Accordingly, the island layer 12 may be connected to the annular conductive layer 40 or the connection terminals 16-1 to 16-4 by use of a metallized layer.
Thus, in the semiconductor circuit device 200 shown in FIG. 2, the ground potential and the power supply voltage are applied to the respective grounding electrodes 2-5 to 2-8 and to the respective power supply electrodes 2-1 to 2-4 from one ground external lead 25-6 and one power supply external lead 25-1, respectively.
The first and second annular conductive layers 19 and 40 are formed by the tungsten metallization and have a thickness of 20 to 30 μm, respectively, as illustrated hereinbefore. For this reason, resistances of these annular conductive layers 19 and 40 may be increased due to the enlargement of their lengths caused by the increase in size of the semiconductor chip 1. As a result, the voltage drops across the annular conductive layers 19 and 40 become large. A semiconductor integrated circuit device having an improvement in resistance of the annular conductive layer is illustrated in FIG. 3. In this figure, the constituents identical to those shown in FIG. 2 are denoted by like reference numerals to omit further descriptions thereof.
The semiconductor integrated circuit device 300 shown in FIG. 3 is of the so-called plug-in type or pin grid array type, in which a plurality of external leads 25 are led out from the bottom of the ceramic base 10 in columns of four. More particularly, the internal wiring layers 17 extending from the respective connection terminals 16 are connected to metallized layers 51 formed on the bottom surface of the base 10 via through-holes 50, respectively. External leads 25 are vertically connected to the bottom surface metallized layers 51 by a brazing material 24 of silver-copper eutectic alloy or tin-lead solder.
In order to lower the resistance of the annular conductive layer 19 applied with the power supply voltage, a metallic member 55 made of copper and having an annular shape is mounted on the annular conductor layer 19 with brazing material 56. Consequently, the thickness of the annular conductive layer 19 is made thicker, resulting in a low resistance. Silver-copper eutectic brazing material is selected as the brazing material 56, and therefore the metallic member 55 is mounted in the same step of connecting the external leads 25. As an alternative, the connections can be made with low melting point brazing material 56 such as a tin-lead solder.
For the purpose of lowering the resistance of the annular conductive layer 40 supplied with the ground potential, an additional alumina ceramic sheet 10-5 is interposed between the ceramic sheets 10-1 and 10-2, and the annular conductive layer 40 is formed on this ceramic sheet 10-5. In the embodiment shown in FIG. 2, the annular conductive layer 40 is covered with the sheet 10-2, and therefore its thickness cannot be made thick. Accordingly, the ceramic sheet 10-5 having a hole 60 of the size slightly larger than that of the island layer 12 and smaller than the hole 15 of the ceramic sheet 10-2, is interposed between the ceramic sheets 10-1 and 10-2. The annular conductive layer 40 is formed on a surface portion of the sheet 10-5 which is not covered with the sheets 10-1 and 10-2. Further, a layer of a brazing material 61 is coated over the annular conductive layer 40 to reduce the resistance of the layer 40. By selecting silver-copper eutectic alloy for the brazing material 61, the coating of the brazing material layer 61 can be formed simultaneously with the step of connecting the external leads 25 by the brazing material 24 of silver-copper eutectic alloy. More particularly, five unsintered ceramic sheets 10-1 to 10-5 which are selectively subjected to the tungsten metallization are superposed, and these ceramic sheets are integrally combined by sintering. A silver-copper eutectic alloy frame having the approximately same shape as the annular conductive layer 40 is stamped out from a silver-copper eutectic alloy plate, and the stamped frame is superposed on the annular conductive layer 40. By making use of the heat-treatment for connecting the external leads 25 to the bottom surface metallized layers 51, the stamped frame of silver-copper eutectic alloy is melted to coat the layer 40 with the brazing material 61. A low melting point brazing material such as a tin-lead solder may be employed for the brazing materials 61 and 24. Likewise, in place of the copper frame 55, the coating of the brazing material may be formed on the annular conductive layer 19. On the contrary, a copper frame may be attached on the annular conductor layer 40.
The semiconductor integrated circuit device 300 in FIG. 3 has the following additional difference as compared to the device shown in FIG. 2. That is, the respective electrodes 2 of the semiconductor chip 1 are not connected through bonding wires to the respective connection terminals 16 but are connected through a tape carrier 65. The tape carrier 65 has a plurality of copper foils selectively formed on an insulator sheet made of polyimide or the like. The tape carriers 65 are also applicable to the semiconductor integrated circuit devices shown in FIGS. 1 and 2.
Thus, the semiconductor integrated circuit device 300 shown in FIG. 3 further improves the potential shifts of the power supply voltage and the ground potential caused by the impedances of the annular conductor layers 19 and 40.
FIGS. 4A and 4B show a fourth preferred embodiment of the present invention. The semiconductor integrated circuit device often necessitates two kinds of power supply voltages V 1 and V 2 (V 1 ≠V 2 ) besides the ground potential. To that end, the semiconductor integrated circuit device 400 shown in FIGS. 4A and 4B is provided with an additional annular conductive layer 80 around the annular conductive layer 19. The annular conductive layers 19 and 80 are applied with the power supply voltages V 1 and V 2 , respectively. The V 1 voltage annular conductor layer 19 is connected via three through-holes 82 to 84 to three connection terminals 16-12 to 16-14, respectively. These connection terminals 16-12 to 16-14 are respectively connected to the V 1 voltage electrodes 2-12 to 2-14 of the semiconductor element 1 through the bonding wires 13. One connection terminal 16-13 is connected via an internal wiring layer 17-13 to a side surface metallized layer 23-13 of the base body 10. A V 1 voltage external lead 25-13 is connected to the side surface metallized layer 23-13 with brazing material 24. Accordingly, the V 1 power supply voltage is applied to three electrodes 2-12 to 2-14 through one external lead 25-13, respectively.
The V 2 voltage annular conductive layer 80 is connected via three through-holes 85 to 87 to three connection terminals 16-15 to 16-17, respectively. These connection terminals 16-15 to 16-17 are respectively connected to the V 2 voltage electrodes 2-15 to 2-17 through the bonding wires 13. The connection terminal 16-15 is connected through an internal wiring layer 17-15 to a side surface metallized layer 23-15 to which a V 2 voltage external lead 25-15 is connected. Accordingly, the V 2 power supply voltage is applied to three electrodes 2-15 to 2-17 through one external lead 25-15, respectively.
The semiconductor integrated circuit device 400 shown in FIGS. 4A and 4B may have the grounding annular conductor layer 40 in accordance with the teaching in FIG. 2, and further the resistance of the respective annular conductor layers can be lowered according to the teaching in FIG. 3. If only one power supply voltage is applied to the semiconductor chip 1, the external lead 25-15 electrically connected to the annular conductive layer 80 may be used as a ground terminal.
Two annular conductor layers 19 and 80 may be disposed on the different planes from each other to reduce the area of the entire package. To this end, an additional alumina ceramic sheet 10-6 having the annular conductive layer 80 formed on its top surface is interposed between the ceramic sheets 10-3 and 10-4 as shown in FIG. 5A and 5B. In this case, the connection between the annular conductor layer 80 and the connection terminals 16-15 to 16-17 is performed by making use of side surface metallized layers (one layer 90 being shown in FIG. 5A) or through-holes (one through-hole 95 being shown in FIG. 5B) penetrating through the other annular conductive layer 19 as insulated therefrom as shown in FIG. 5B. The connection between the annular conductor layer 19 and the connection terminal 16-13 (not shown in FIGS. 5A and 5B) also utilize side surface metallized layers or through-holes.
It is apparent that the present invention should not be limited to the above-described embodiments and many modifications can be made without departing from the spirit of the present invention. For instance, the present invention can be applicable to the semiconductor integrated circuit device of the QIP (Quadle In-line Package) type or the SIP (Single In-line Package) type. In addition, the materials of the insulator base 10, external leads 25, the lid 70, the respective metallized layer, etc. are not limited to those shown in the above-described embodiments.
As described in detail above, according to the present invention, the number of electrodes of the semiconductor chip for power supply use and/or for grounding use can be increased without increasing the number of external leads of the package.
|
The present invention relates to a semiconductor device including a package for carrying a semiconductor element or chip having a plurality of components, such as transistors, diodes, etc. to which substantially the same voltage is to be applied. The voltage may be supplied to a plurality of electrodes distributed on the semicnductor element. Excessive voltage drop between the components and external leads of the device is inhibited by providing a package with at least one low resistance conductive layer about the periphery of the device which is electrically connected to an external lead of the device and to a plurality of electrodes on the semiconductor element.
| 7
|
FIELD OF THE INVENTION
The invention relates to the field of computer buses and specifically to the field of controllable terminators for computer buses.
BACKGROUND OF THE INVENTION
In a computer system, the processor, the memory, and the input/output (I/O) devices communicate with one another by way of a bus. A bus is a series of conductors, each of which is capable of transmitting signals which represent either data to be transferred between devices on the bus or control information, such as device addresses, which determine when and to where the data being transferred by the bus is to be transferred. The signals transferred on the bus typically take the form of rapidly changing bi-stable voltage levels. These voltage levels are placed on the conductors by bus drivers incorporated into each device which communicates with the bus. For optimum signal power transfer between devices and minimum signal reflection, the bus must be terminated in such a way that the impedance of the bus matches the impedance of the bus drivers. The bus impedance should be held approximately constant.
Generally, bus terminators take the form of modular devices. The bus terminator is physically inserted onto the bus to provide termination and physically removed from the bus to remove termination, for example, when the bus is to be extended. Such changing of the bus termination requires physical access to the bus, which in turn requires the opening of the enclosures protecting the devices and bus.
The present invention permits a bus terminator to be connected to and disconnected from a bus electrically and without being physically moved.
Another feature of the invention is that when the terminator is disconnected from the bus, its internal power supply is reduced substantially.
SUMMARY OF THE INVENTION
The invention relates to a controllable terminator for a computer bus which is capable of being electrically connected to and disconnected from the bus by means of a control signal.
The terminator includes a voltage regulator portion, a control portion and a series of bus terminating resistors, each of which is connected through a transistor switch for connecting each of the resistors to the regulated voltage. The voltage regulator portion includes a power-down circuit to turn the voltage regulator portion off, using the same control signal which disconnects the terminating resistors.
The control portion uses a single external signal voltage level both to cause the series of bus terminating transistor switches to switch and to cause the voltage regulator portion to turn on and off for reduced power consumption. In one embodiment, the control portion includes a comparator to determine the voltage level at which switching is to take place.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the invention will be more readily understood in view of the accompanying specification and drawings in which:
FIG. 1 is a diagram of a computer system utilizing a bus terminator known to the prior art;
FIG. 2 is a block diagram of an embodiment of the invention;
FIG. 3 is a schematic diagram of an embodiment of the invention shown in FIG. 2; and
FIG. 4 is a schematic diagram of an embodiment of the switching portion of the embodiment of the invention shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a computer system 10 includes a series of devices 10 each communicating with a processor 14 and one another over a bus 12. Each end of the bus 12 terminates at a terminator 16.
Referring now to FIG. 2, in brief overview, an embodiment of the controllable terminator 90 of the invention can be roughly separated into a control portion 92, a voltage regulator portion 94 and a switching portion 96. The control portion 92 controls the connection of the bus 12, through a series of resistors 98, to the voltage regulation portion 94 by means of a series of switches 100 connected between the resistors 98 and the voltage regulation portion 94. In the embodiment shown, the control portion 92 includes a disconnect comparator 102 which produces a control voltage on its output terminal 104 in response to a disconnect control signal applied to one of its input terminals 106. When the disconnect control signal is high, the output signal of the comparator 102 opens the series of switches 100 and turns off the voltage regulator 106 of the voltage regulator portion 94. When the disconnect control signal is low, the voltage regulator portion 94 is activated and the switches 100 are closed, connecting the bus 12 to the voltage regulation portion 94 through the resistors 98. Thus the disconnect control signal permits the controllable terminator 90 to be connected or removed electrically from the bus 12 and the power supply 116, without being physically removed from the system.
Referring now also to FIG. 3, the voltage regulator portion 94 includes a voltage differential amplifier 120 which has a first input terminal 122 connected to a bandgap reference 124. In the embodiment shown the bandgap reference 124 is set to 2.85 V, but other voltage references may be used to produce other voltage levels. A second input terminal 126 of the differential amplifier 120 is connected to the regulator output 127 through the transistor switch 130. Differential amplifier 120 works with transistor 140 and switchable current source 150 in order to control the conduction of power transistor 142 and thereby hold the regulator's output voltage constant in a manner well known in the art. Current source 150, which provides the bias current to power transistor 142 is connected to the power supply terminal 116 through transistor switch 144.
When transistor 144 is on, the current supply 150 provides bias current to the power transistor 142, subject to the degree of control provided by differential amplifier 120 and transistor 140. Conversely, when transistor 144 is off, the base current of transistor 142 is interrupted turning it off and causing both the regulator's output voltage to fall to zero volts and the internal power consumption to drop to substantially zero. The turning on and off of transistor 144 is controlled by the control portion 92 of the terminator 90 and will be discussed in more detail below.
The switching portion 96 of the terminator 90 includes a series of terminating resistors 98, each associated with a bus line 172 and the series of switching transistors 100, each associated with a respective resistor 98. A high control voltage applied to the base of each transistor 100 causes each to conduct, connecting its respective bus line 172 to the voltage regulator portion 94 through the resistors 98. Conversely, a low control voltage turns off each transistor 100, electrically disconnecting each bus line 172 from the voltage regulator and causing each bus connection 172 to appear as a high impedance to the bus 12.
The control portion 92 includes a voltage divider 160 which includes two resistors 162,164 connected between the power supply 116 and ground 112. The resistors 162,164 are selected so as to provide a defined voltage level to a first input terminal 168 of the disconnect comparator 102. In the embodiment shown, the power supply connected to terminal 116 is set for 4.75 V, the divider 160 establishes a threshold of 1.4 V at the first terminal 168 of the comparator 102. A voltage level applied to a second input terminal 108 of the comparator 102 is the disconnect control signal to connect or disconnect the terminator 90 from the bus 12.
In the embodiment shown, when the voltage of the disconnect signal at the second input terminal 106 of the disconnect comparator 102 is below 1.4 V, the signal on the output terminal 104 of the disconnect comparator 102 goes high. This signal is inverted by invertor 170 and applied to the base of transistor 144, turning it on. This permits current from the current source 150 to be applied to the base of power transistor 142 turning it on and permitting the feedback loop consisting of transistors 140, 142 and differential amplifier 120 to regulate the voltage level. At the same time, the high signal on the output terminal 104 of disconnect comparator 102 is applied to the base of transistors 100 and 130, turning them on. The purpose of transistor 130 is to provide a voltage offset in the regulator feedback loop matching the voltage drop across each conducting transistor 100. The offset allows the regulator to hold the voltage of all terminating resistors 98 exactly equal to the regulator's reference voltage, with any variable voltage drop across transistor switches 100 cancelled by the voltage drop across transistor 130.
Conversely, when the signal voltage on the second input 108 of the disconnect comparator 102 goes above the voltage level on the first input 170, the output signal on the output terminal 104 of the disconnect comparator 102 goes low. This low signal is inverted to high by invertor 170 causing transistor 144 to shut off the voltage regulation portion 92 of the controllable terminator 90.
At the same time, the low output signal of the disconnect comparator 102 shuts off transistor 130 breaking the feedback loop to the comparator 102 from the power supply 116. The same signal which controls the voltage regulator portion 94 is also applied to the base of each transistor 100 causing each of the transistors 100 to turn off, electrically disconnecting each of the bus lines 172 from the terminator 90.
Additionally, each bus line 172 includes a voltage clamp which includes a transistor 178 and current source 174 connected through a diode 176 to ground 112. The base of clamp transistor 178 is connected between the current source 174 and diode 176, while the emitter of the transistor 178 is connected to the bus line 172. If the signal on the bus line 172 undergoes ringing and attempts to become negative because of signal reflection, transistor 178 conducts, clamping the voltage on the bus line 172 at zero volts.
It should also be noted that sensors producing signals indicative of over current 180 and overheating 182 are also incorporated in the circuit and provide input signals to a NOR gate 190. If either of these signals are present, the output signal from the NOR gate 190 goes low shutting off transistor 142 and thereby shutting off power to the terminator 90.
One embodiment of the controllable terminator 90 is constructed as a single chip integrated circuit having thin film resistors 98. In such an integrated circuit it is possible to trim the resistors 98 which would normally have a production tolerance of ±10% to within ±2.5% without increasing the control required in the manufacturing process. This is accomplished by the use of an additional circuit in the switching portion 96 of the controllable terminator 90. An embodiment of such a trimming circuit is shown in FIG. 4.
In this embodiment, each of the resistors 98 in the terminator 90 have been replaced by a transistor-resistor network 98'. In FIG. 4 only two transistor-resistor networks 98' have been shown for clarity, although each bus line 172 is connected to one. Each network 98' is constructed of three resistors 200, 202, 204 and two transistors 206, 208. In the embodiment shown, the first resistor 200 has a nominal value of one hundred eighteen ohms while the second and third resistors 202, 204 have nominal values of 1.15 k ohms and 2.3 k ohms, respectively. The transistors 206, 208 are configured such that when the switching transistor 100 is turned on by the signal from the disconnect comparator output terminal 104, transistors 206, 208 also turn on. This results in resistors 202 and 204 being connected in parallel with resistor 200, lowering the resistance experienced by the bus line 172.
A zener diode 220 is also connected between the base of each transistor 206, 208 and ground 112. During fabrication, the resistance of the entire network 98' is determined and may be adjusted by pulsing a high current through one or both of the zener diodes 220, shorting them to ground 112. The result of the shorting of a zener diode 220 to ground 112 is that the base of its respective transistor 206 or 208 is also grounded, permanently shutting off the transistor 206 or 208. The shutting off of transistor 206 removes resistor 202 from the network 98' thereby increasing the resistance of the network 98'. Similarly, the shutting off of transistor 208 removes resistor 204 from the network 98' further increases the resistance of the network 98'. By selectively removing one or both of the zener diodes 220, the total network resistance may be adjusted to a close tolerance. Since each thin film resistor in a network 98' is well matched by its corresponding resistor in another network 98' on the same integrated circuit chip, only one measurement need be made on one network 98' to determine the total resistance of all networks 98' in the terminator 90.
Thus, the network 98' permits the adjustment of the total resistance experienced by the bus line 172.
In the network 98' the switching of the transistor 206 of the transistor-resistor network 98' connects and disconnects the resistor 202 from the parallel configuration. The switching of the transistor 206 is determined by the presence of the zener diode 220 connected between the base of the transistor 206 and ground. Thus, a method of adjusting the total resistance of the resistor network 98' circuit includes the steps of measuring the resistance of the network and selectively removing the zener diodes 220 in the networks 98'. The step of selectively removing the zener diodes 220 is here performed by the application of a breakdown current to the selected zener diode 220 to be removed.
Correspondingly, since all network resistors 200, 202, 204 are matched within a chip, the trimming of one resistor network to a specific resistance trims all resistor networks on that chip. Therefore only one zener diode 220 need be fabricated on the chip for each resistor 202, 204, in the network 98', not one zener diode 220 for each resistor 202, 204 for each network 98'. That is, in the embodiment shown, only two zener diodes 220 (one for resistors 202 and one for resistors 204) are fabricated on the chip, regardless of how many networks 98' are fabricated on the chip. Thus trimming one network 98' trims all networks 98' in the terminator 90 and no decrease in manufacturing tolerance is required for the thin film resistors 98 in order to assure that the specification of each terminator resistance is met. It is understood that other modifications or embodiments are possible which will still be within the scope of the appended claims. These and other examples of the concept of the invention illustrated above are intended by way of example and the actual scope of the invention is to be determined solely from the following claims.
|
A controllable bus terminator, for providing a switchable termination on a bus having a plurality of conductors, wherein the controllable bus terminator includes a voltage regulator, a plurality of resistive networks each of the resistive networks having a first terminal and a second terminal wherein the second terminal of each of the resistive networks provides an output terminal of the bus terminator. The bus terminator further includes a plurality of electrically controllable switches, each of the switches having a first port coupled to the voltage regulator and a second port coupled to the first terminal of a corresponding one of the resistive networks wherein each of the switches couple the corresponding resistive network to the voltage regulator when the corresponding switch is in a first state and wherein each of the switches disconnect the corresponding resistive network from the voltage regulator when the corresponding switch is in a second state.
| 8
|
RELATED APPLICATION DATA
[0001] This application is related to Provisional Patent Application Ser. Nos. 60/955,533 filed on Aug. 13, 2007, and 60/956,550 filed on Aug. 17, 2007, and priority is claimed for this earlier filing under 35 U.S.C. §119(e). The Provisional Patent Application is also incorporated by reference into this utility patent application.
TECHNICAL FIELD OF THE INVENTION
[0002] A system and method for a mobile IP-based system, including an IP-based mobile communication system having a home network, foreign network and a mobile node.
BACKGROUND OF THE INVENTION
[0003] IP-based mobile system includes at least one Mobile Node in a wireless communication system. The term “Mobile Node” includes a mobile communication unit, and, in addition to the Mobile Node, the communication system has a home network and a foreign network. The Mobile Node may change its point of attachment to the Internet through these other networks, but the Mobile Node will always be associated with a single home network for IP addressing purposes. The home network has a Home Agent and the foreign network has a Foreign Agent—both of which control the routing of information packets into and out of their network.
[0004] The Mobile Node, Home Agent and Foreign Agent may be called other names depending on the nomenclature used on any particular network configuration or communication system. For instance, a “Mobile Node” encompasses PC's having cabled (e.g., telephone line (“twisted pair”), Ethernet cable, optical cable, and so on) connectivity to the wireless network, as well as wireless connectivity directly to the cellular network, as can be experienced by various makes and models of mobile terminals (“cell phones”) having various features and functionality, such as Internet access, e-mail, messaging services, and the like.
[0005] And, a home agent may be referred to as a Home Agent, Home Mobility Manager, Home Location Register, and a foreign agent may be referred to as a Foreign Agent, Serving Mobility Manager, Visited Location Register, and Visiting Serving Entity. The terms Mobile Node, Home Agent and Foreign Agent are not meant to be restrictively defined, but could include other mobile communication units or supervisory routing devices located on the home or foreign networks. Foreign networks can also be called serving networks.
Registering the Mobile Node
[0006] Foreign Agents and Home Agents periodically broadcast an agent advertisement to all nodes on the local network associated with that agent. An agent advertisement is a message from the agent on a network that may be issued under the Mobile IP protocol (RFC 2002) or any other type of communications protocol. This advertisement should include information that is required to uniquely identify a mobility agent (e.g. a Home Agent, a Foreign Agent, etc.) to a mobile node. Mobile Nodes examine the agent advertisement and determine whether they are connected to the home network or a foreign network.
[0007] If the Mobile Node is located on its home network, information packets will be routed to the Mobile Node according to the standard addressing and routing scheme. If the Mobile Node is visiting a foreign network, however, the Mobile Node obtains appropriate information from the agent advertisement, and transmits a registration request message to its Home Agent through the Foreign Agent. The registration request message will include a care-of address for the Mobile Node. A registration reply message may be sent to the Mobile Node by the Home Agent to confirm that the registration process has been successfully completed.
[0008] The Mobile Node keeps the Home Agent informed as to its current location by registering a “care-of address” with the Home Agent. The registered care-of address identifies the foreign network where the Mobile Node is located, and the Home Agent uses this registered care-of address to forward information packets to the foreign network for subsequent transfer onto the Mobile Node. If the Home Agent receives an information packet addressed to the Mobile Node while the Mobile Node is located on a foreign network, the Home Agent will transmit the information packet to the Mobile Node's current location on the foreign network using the applicable care-of address.
Authentication, Authorization and Accounting (“AAA”)
[0009] In an IP-based mobile communications system, when a mobile node travels outside its home administrative domain, the mobile node may need to communicate through multiple domains in order to maintain network connectivity with its home network. While connected to a foreign network controlled by another administrative domain, network servers must authenticate, authorize and collect accounting information for services rendered to the mobile node. This authentication, authorization, and accounting activity is called “AAA”, and AAA servers on the home and foreign network perform the AAA activities for each network.
[0010] Authentication is the process of proving one's claimed identity, and security systems on a mobile IP network will often require authentication of the system user's identity before authorizing a requested activity. The AAA server authenticates the identity of an authorized user and authorizes the mobile node's requested activity. Additionally, the AAA server will also provide the accounting function including tracking usage and charges for use of transmissions links between administrative domains.
[0011] Another function for the AAA server is to support secured transmission of information packets by storing and allocating security associations. Security associations refer to those encryption protocols, nonces, and keys required to specify and support encrypting an information packet transmission between two nodes in a secure format. The security associations are a collection of security contexts existing between the nodes that can be applied to the information packets exchanged between them. Each context indicates an authentication algorithm and mode, a shared or secret key or appropriate public/private key pair, and a style of replay protection.
[0012] The current registration and authentication protocols are not efficient because they require the re-transmission of registration and authentication request messages in certain time-out situations. The re-transmission of the registration and authentication request messages may be unnecessary in these situations, and such a re-transmission of these messages may result in multiple request messages being transmitted onto the network when only one request message was needed.
SUMMARY OF THE INVENTION
[0013] The invention consists of a new registration and authentication protocol for between a Mobile Node and a Home Agent. The new protocol will use a novel messaging sequence to request registration, authentication and authorization of the Mobile Node when it is located on a foreign network, and the novel protocol will avoid some of the standard registration and authentication protocol messages in order to eliminate the problems associated with re-transmission errors.
[0014] The initial sequence of messaging in the protocol will be conducted between the Mobile Node, Foreign Agent, foreign AAA server and home network AAA server, before a registration request is allowed to be sent to the Home Agent. The initial registration request message is transmitted to the Home Agent only after the successful completion of the initial message sequence between the other components on the network. The home agent will exchange messages with its home agent AAA server to confirm authentication and authorization on the home network, and if successful, the home agent will respond to the registration request with a response that is sent back to the Mobile Node on the foreign network. The invention can be implemented using a new protocol application or using modified messages from prior registration applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The objects and features of the invention will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements and in which:
[0016] FIG. 1 is a mobile IP-based communication system as used in the present invention;
[0017] FIG. 2 is a message sequence for registration and authentication protocol used in the prior art.
[0018] FIG. 3-4 are message sequences for the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In FIG. 1 , the overall architecture of the IP-based mobile system is shown with a Mobile Node 64 , a home network 10 and a foreign network 40 . As shown in FIG. 1 , the home network 10 and the foreign network 40 are coupled to the Internet represented by the cloud 35 . The home network 10 has a central buss line 20 coupled to the Home Agent 28 via communication link 24 . The buss line 20 is coupled to the AAA server 17 via communication link 22 . The home network 10 is coupled to the Internet 35 via communication link 30 . A communications link is any connection between two or more nodes on a network or users on networks or administrative domains.
[0020] The foreign network 40 has a central buss line 50 coupled to the foreign agent 58 via communication link 54 . The buss line 50 is coupled to the AAA foreign network server 47 via communication link 52 . The foreign network 40 is coupled to the Internet 35 via communication link 37 . Mobile Node 64 is shown electronically coupled to the foreign network 40 via the wireless communication link 66 of transceiver 60 . Transceiver 60 is coupled to the foreign network 40 via communication link 62 . The Mobile Node 64 can communicate with any transceiver or Access Network coupled to the foreign network 40 .
[0021] The terms Home Agent and Foreign Agent may be as defined in the Mobile IP Protocol (RFC 2002), but these agents are not restricted to a single protocol or system. In fact, the term Home Agent, as used in this application, can refer to a Home Mobility Manager, Home Location Register, Home Serving Entity, or any other agent at a home network 10 having the responsibility to manage mobility-related functionality for a Mobile Node 64 . Likewise, the term Foreign Agent, as used in this application, can refer to a Serving Mobility Manager, Visited Location Register, Visiting Serving Entity, or any other agent on a foreign network 40 having the responsibility to manage mobility-related functionality for a Mobile Node 64 .
[0022] In the mobile IP communications system shown in FIG. 1 , the Mobile Node 64 is identified by a permanent IP address. While the Mobile Node 64 is coupled to its home network 10 , the Mobile Node 64 receives information packets like any other fixed node on the home network 10 . When mobile, the Mobile Node 64 can also locate itself on foreign network 40 . When located on foreign network 40 , the home network 10 sends data communications to the Mobile Node 64 by “tunneling” the communications to the foreign network 40 .
[0023] The Mobile Node 64 keeps the Home Agent 28 informed of its current location, or foreign network association, by registering a care-of address with the Home Agent 28 . Essentially, the care-of address represents the foreign network 40 where the Mobile Node 64 is currently located. If the Home Agent 28 receives an information packet addressed to the Mobile Node 64 while the Mobile Node 64 is located on a foreign network 40 , the Home Agent 28 will “tunnel” the information packet to foreign network 40 for subsequent transmission to Mobile Node 64 .
[0024] The Foreign Agent 58 participates in informing the Home Agent 28 of the Mobile Node's 64 current care-of address. The Foreign Agent 58 also receives information packets for the Mobile Node 64 after the information packets have been forwarded to the Foreign Agent 58 by the Home Agent 28 . Moreover, the Foreign Agent 58 serves as a default router for out-going information packets generated by the Mobile Node 64 while connected to the foreign network 40 .
[0025] The Mobile Node 64 participates in informing the Home Agent 28 of its current care-of address. When the Mobile Node 64 is visiting a foreign network 40 , the Mobile Node 64 obtains appropriate information regarding the address of the foreign network 40 and/or the Foreign Agent 58 from an agent advertisement. After obtaining this information, the Mobile Node 64 transmits the registration request to the Foreign Agent 58 , which prepares the registration request message for forwarding to the Home Agent 28 .
[0026] Mobile IP protocols require that the mobile node register the care-of address with the Home Agent 28 on the home network 10 after movement to a new foreign network 40 . As part of the registration process, the Mobile Node 64 issues a registration request in response to power-up on the foreign network 40 or receipt of an agent advertisement. A registration request message can be sent to the home network 10 that includes a care-of address for the Mobile Node 64 . A registration reply is issued by the home network 10 to acknowledge receipt of the registration request, confirm receipt of the care-of address for the Mobile Node 64 , and indicate completion of the registration process.
[0027] The care-of address identifies the foreign network 40 where the Mobile Node 64 is located, and the Home Agent 28 uses this care-of address to tunnel information packets to the foreign network 40 for subsequent transfer to the Mobile Node 64 . After registration is completed, the Home Agent 28 receives this communication and “tunnels” the message to the Mobile Node 64 on the foreign network 40 . The Foreign Agent 58 accepts the re-directed communication and delivers the information packet to the Mobile Node 64 through the transceiver 60 . In this manner, the information packets addressed to the Mobile Node 64 at its usual address on the home network 10 is re-directed or forwarded to the Mobile Node 64 on the foreign network 40 . The Foreign Agent 58 may also serve as a router for “outbound” information packets generated by the Mobile Node 64 while connected to the foreign network 40 depending on the delivery style chosen.
[0028] FIG. 2 shows the message sequence using a known protocol (RF 4004) for the registration and authentication of the Mobile Node 64 on a foreign network. In step 210 , the registration request RRQ is transmitted from the Mobile Node 64 to the Foreign Agent 58 . The registration request RRQ message is received and a new registration message AMR is formed by the Foreign Agent 58 , and, at step 220 , that message is transmitted from the Foreign Agent 58 to the AAAF server 47 on the foreign network. The AMR message is transmitted from the AAAF server 47 to the AAAH server 17 at step 230 , where a new registration request message HAR is generated and transmitted from the AAAH 17 to the Home Agent 28 at step 240 .
[0029] The Home Agent 28 analyzes this HAR message before responding to that message with a registration response message HAA, which is transmitted back to the AAAH server 17 at step 250 . The AAAH server 17 forms a new registration response message AMA at the AAAH server 17 and transmits that new registration response message AMA to the AAAF server 47 at step 260 . The AAAF server 47 forwards the registration response message AMA to the Foreign Agent 58 at step 270 , where a new registration response message RRP is formed. The Foreign Agent 58 transmits the new registration response message RRP to the Mobile Node 64 at step 280 .
[0030] This known protocol uses three different registration messages and three different registration response messages, all transmitted sequentially in eight steps between five components. Delays may occur at any stage in the protocol sequence, and if the registration request or registration response messages are delayed to a substantial degree, the Mobile Node 64 may re-issue its registration request under the assumption that the prior registration request was lost or failed transmission. This re-issue and re-transmission of the registration request may be unnecessary, and could cloud the networks with registration messages that should not otherwise have been issued and transmitted. The present invention eliminates the possibility for such problems by simplifying the request and response message sequence for registration and authentication.
[0031] FIG. 3 shows the message sequence using the present invention for the registration and authentication of the Mobile Node 64 on a foreign network. In step 310 , the registration request RRQ is transmitted from the Mobile Node 64 to the Foreign Agent 58 . The registration request RRQ message is received and a new registration message AMR is formed by the Foreign Agent 58 , and the AMR message is transmitted from the Foreign Agent 58 to the AAAF server 47 on the foreign network at step 320 . The AMR message is transmitted from the AAAF server 47 to the AAAH server 17 at step 330 .
[0032] Instead of allowing the request messages to be communicated directly to the Home Agent, the initial message sequence first requires the AAAH 17 to analyze the request message AMR and then prepare a response message AMA that is transmitted from the AAAH 17 to AAAF 47 at step 340 . The AAAF 47 transmits the response message AMA to the Foreign Agent 58 at step 350 . The initial message sequence is finalized with the receipt of that AMA message at step 350 .
[0033] After confirmation that the registration request has been approved and authenticated by the AAAH 17 through the AMA response message received by the Foreign Agent, the Foreign Agent forwards the registration request RRQ message initially received from the Mobile Node 64 directly to the Home Agent 28 at step 360 . The Home Agent transmits an AMR request message to the AAAH 17 at step 370 based on the receipt of the request message RRQ, and the AAAH 17 responds to the AMR request message with the transmission of a registration response AMA message at step 380 . With the receipt of the AMA message at step 380 , the Home Agent 28 confirms the ability to register the Mobile Node 64 .
[0034] After authentication and registration at the Home Agent 28 , the Home Agent 28 transmits a registration response message RRP to the Foreign Agent 58 at step 390 , and the Foreign Agent 58 forwards this registration response message to the Mobile Node 64 at step 395 . With the receipt of the registration response message RRP by the Mobile Node 64 , the registration and authentication protocol is completed. This protocol uses a reduced number of different message formats (four formats) compared to the prior art protocol, which assists in the reduction in the possibility that delays would occur and these delays would initiate re-transmissions of the registration request message.
[0035] FIG. 4 shows the message sequence using the present invention for the registration and authentication of the Mobile Node 64 on a foreign network. In step 405 , the initial message sequence is designated by the EAP Authentication communicated between the Mobile Node 64 , Foreign Agent 58 , LAAA 147 (corresponds to AAAF 47 ), and the HAAA 17 . This EAP Authentication 405 allows the Mobile Node 64 to be authenticated by the HAAA 17 through an initial sequence of messages. Instead of allowing the request messages to be communicated directly to the Home Agent, the initial message sequence first requires the AAAH 17 to analyze the request message and confirm authentication back to components on the foreign network 40 .
[0036] After step 405 , the registration request RRQ is transmitted from the Mobile Node 64 to the Foreign Agent 58 at step 410 . After confirmation that the registration request has been approved and authenticated by the AAAH 17 through the EAP Authentication 405 , the Foreign Agent forwards the registration request RRQ message initially received from the Mobile Node 64 directly to the Home Agent 28 at step 420 . The Home Agent transmits an AMR request message to the AAAH 17 at step 430 based on the receipt of the request message RRQ, and the AAAH 17 responds to the AMR request message with the transmission of a registration response AMA message at step 440 . With the receipt of the AMA message at step 440 , the Home Agent 28 confirms the ability to register the Mobile Node 64 .
[0037] After authentication and registration at the Home Agent 28 , the Home Agent 28 transmits a registration response message RRP to the Foreign Agent 58 at step 450 , and the Foreign Agent 58 forwards this registration response message to the Mobile Node 64 at step 460 . With the receipt of the registration response message RRP by the Mobile Node 64 , the registration and authentication protocol is completed. This protocol uses a reduced number of different message formats (four formats) compared to the prior art protocol, which assists in the reduction in the possibility that delays would occur and these delays would initiate re-transmissions of the registration request message.
|
The invention consists of a new registration and authentication protocol for between a Mobile Node and a Home Agent. The new protocol uses a novel messaging sequence to request registration, authentication and authorization of the Mobile Node when it is located on a foreign network, and the novel protocol will avoid some of the standard registration and authentication protocol messages in order to eliminate the problems associated with re-transmission errors.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 10 2011 121 260.8, filed Dec. 15, 2011, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The technical field relates to a method for assisting the driver of a motor vehicle, as well as to a motor vehicle for implementing the method.
BACKGROUND
[0003] So-called assistance systems can be used for assisting drivers of a motor vehicle. These can intervene in the driving dynamics of the motor vehicle in a manner relevant to safety and/or influence a behavior of the driver of the motor vehicle, in particular by issuing warnings. Known are systems that evaluate driver alertness based on a prescribed desired behavior and a determined actual behavior of the driver. DE 10 2010 048 273 A1 relates to a method and driver assistance system for initiating a vehicle action as a function of alertness. The method here encompasses determining a vehicle position on a digital roadmap of a navigation system. In addition, a local vehicle environment is acquired in the form of environmental sensor data by at least one first vehicle sensor device, a local environmental map is generated from the environmental sensor data, and the vehicle position on the digital roadmap is reconciled with the local environmental map, wherein this yields a localized vehicle position that is detailed in terms of environmental information. A movement of the vehicle is then ascertained by at least one second vehicle sensor device, and the course of a road is identified from the digital roadmap of the navigation system based on the vehicle position, and an actual traveling route is finally determined from the localized vehicle position and movement of the vehicle, and the actual traveling route is compared with the desired traveling route, which is determined at least by the course of the road. Comparing the actual and desired traveling routes makes it possible to deduce the alertness of a driver and an alertness status value is assigned. After the alertness status value has been compared to a prescribed threshold value and found to deviate by a predetermined amount, the vehicle action is initiated. DE 10 2009 005 730 A1 relates to a method for monitoring the alertness of the driver of a motor vehicle involving the following steps: Determining an actual viewing direction, i.e., the direction in which the driver is looking, determining a desired viewing direction, i.e., the direction in which the driver should be looking to safely drive the motor vehicle, evaluating the actual viewing direction based on the desired viewing direction to ascertain the alertness or inattentiveness of the motor vehicle driver, determining an allotted timeframe within which an inattentiveness on the part of the motor vehicle driver can be tolerated, determining the duration of inattentiveness if an inattentiveness on the part of the motor vehicle driver has been ascertained, and comparing it to the allotted timeframe, alerting the driver if the duration has been exceeded, wherein the method is characterized in that the desired viewing direction and/or allotted timeframe are determined as a function of the position of a turn signal, information about the course of the road ahead of the motor vehicle, and/or information from a lane departure warning system.
[0004] Therefore it may be desirable to enable the highest possible level of safety at the lowest possible error rate by assisting the driver of a motor vehicle through alertness recognition, even for the various driving styles of potentially different drivers. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
[0005] According to various exemplary embodiments, provided is an error counter that is advantageously activated when the actual driver behavior of the driver deviates from his or her desired driver behavior. This also holds true at a specific frequency for a conventional driving style. The evaluation parameter is advantageously determined as a function of a change in the error counter over time, so that a change in the driver behavior of the driver can advantageously be ascertained, in one example, because he or she is fatigued or another activity that demands his or her attention has begun. The evaluation parameter is advantageously compared with the lower threshold, and the reaction is initiated as a function thereof only if the lower threshold has been exceeded. The reaction advantageously acts either directly on the behavior of the driver, so that the latter in one example refocuses his or her attention on his or her driving once again, and/or on the behavior of the motor vehicle, in one example for adapting to typical driver traits, such as driving styles, especially to adjust safety-relevant systems to the diminished alertness. Maximum safety is advantageously also enabled for various driving styles of potentially different drivers, while keeping the error rate as low as possible. The error rate can here be understood as the frequency of erroneously issued driver warnings and/or performed interventions and/or changes by/to driver assistance systems.
[0006] One exemplary embodiment of the method according to the present disclosure includes an upper threshold that is advantageously also prescribed. A determination is advantageously made of whether the evaluation parameter lies between the upper threshold and lower threshold. This can advantageously be regarded as a criterion for the deviating actual driver behavior on the part of the driver, but does not allow an inference of a loss in alertness. Involved here in one example, is a common deviation in the behavior of a driver, for example because the latter prefers a sporty driving style, and/or his or her ability is subject to fluctuation. In this case, the desired driver behavior parameter can advantageously be adjusted in such a way as to provide a greater correlation between the actual driver behavior and desired driver behavior. This advantageously makes it possible to achieve an adaptation to the altered driver behavior of the driver.
[0007] Another exemplary embodiment of the method includes a first threshold value that is advantageously adapted to the altered or deviating driver behavior. The driver of the motor vehicle can be regarded as part of a so-called man-in-the-loop control system, in one example, for controlling the longitudinal dynamics and/or transverse dynamics of the motor vehicle via inputs at a man-machine interface, in one example, a steering wheel and/or torque interface. In one example, a typical control task has to do with establishing a braking point before an obstacle and/or traffic signals based upon which the advantages will be exemplarily explained. Different drivers here exhibit varying qualities, which manifest themselves in the control quality. The drivers can here apply the brakes at a high level of deviation around the prescribed braking point, meaning often do so somewhat sooner or somewhat later. Adapting the first threshold advantageously enables an adaptation to the control quality of such a man-in-the-loop control system. An adaptation can advantageously be made to drivers who drive very accurately or inaccurately.
[0008] Another exemplary embodiment of the method includes that only the amount by which the desired driver behavior parameter differs from the actual driver behavior parameter is included in ascertaining driver alertness. As a result, deviations in both directions can advantageously be acquired. In one example, driver errors going in both directions are encountered given a loss in alertness, for example a braking point that is clearly too late or too early, a speed that is clearly too high, or a speed that is clearly too low, which can advantageously also be acquired through value computation, and are incorporated into the evaluation parameter.
[0009] Another exemplary embodiment of the method includes that a desired driving trajectory can advantageously be determined by means of driver assistance systems and/or navigation systems that are present anyway. A deviation in driving trajectory can advantageously be used as a criterion for a loss in alertness. In one example, this case can involve directional stability during straight line travel and/or cornering behavior. Alternatively or additionally, the braking point can advantageously be used while approaching the car in front, maintaining a distance from the car in front and/or stopping in front of traffic signs, for example, traffic signals, and thus be included in the evaluation parameter. In like manner, this can be accomplished by prescribing an acceleration, in one example, when entering into a curve, exiting a curve, driving through a curve, adjusting a distance from the car in front and/or leaving a traffic sign, for example a stop sign and/or traffic signals, such as intersection lights. In one example, a reaction time to a traffic signal light can be used to prescribe the desired driver behavior.
[0010] Another exemplary embodiment of the method includes that the viewing direction of the driver can be prescribed as the desired driver behavior. An early or late change in the view or viewing direction that is included in the evaluation parameter via the advantageous evaluation over time can advantageously provide information about the alertness of the driver of the motor vehicle.
[0011] Another exemplary embodiment of the method includes that the time and/or duration of the blinker can advantageously also provide information about the alertness of the driver of the motor vehicle, and be included in the evaluation parameter. In one example, forgetting to turn on the blinker can provide information about the alertness of the driver.
[0012] Another exemplary embodiment of the method includes that drivers of motor vehicles usually exhibit characteristic peculiarities when shifting the manual transmission of a motor vehicle. Shifting points that change or deviate from the desired driver behavior can advantageously also be used to calculate the evaluation parameter.
[0013] Another exemplary embodiment of the method includes that motorists usually follow the speed limits dictated by traffic signs by correspondingly braking or accelerating the vehicle. Given a diminishing alertness, the degree of compliance changes, in one example, toward faster speeds or slower speeds than prescribed by traffic rules. This circumstance can advantageously be included in the evaluation parameter. In one example, different drivers exhibit varying deviations relative to the prescribed speeds, for example drive basically somewhat slower or basically somewhat faster than prescribed. An adaptation can advantageously be made to this offset if accompanied by an evaluation parameter between the upper threshold and lower threshold. In cases where the deviations are only slight or arise only occasionally, the evaluation parameter advantageously remains under the lower threshold, so that no adaptation takes place.
[0014] Another exemplary embodiment of the method includes that in a motor vehicle with partially automated and/or automated operation, in particular a mode of operation that no longer requires that the driver of the motor vehicle have his or her hands on the steering wheel and/or feet on the pedals, driver reactions are still necessary, for example to respond to warnings or a so-called dead man's switch. These reactions can advantageously also be adapted with regard to the premises of the respective driver, and included in the evaluation parameter.
[0015] Another exemplary embodiment of the method includes that the driver can advantageously be warned as a function of the evaluation parameter, in one example, to restore his or her alertness again and/or induce him or her to take a break. Driving safety can advantageously be elevated in this way.
[0016] Another exemplary embodiment of the method includes that the upper threshold can advantageously be used to warn the driver. Alternatively or additionally, a warning threshold deviating from the upper threshold can also be established, wherein the driver is warned once the evaluation parameter has exceeded the warning threshold.
[0017] Another exemplary embodiment of the method includes that the motor vehicle advantageously exhibits additional assistance systems, which intervene in the driving dynamics of the motor vehicle and/or issue warnings to the driver. For example, these can be driving dynamics controllers, side slip angle controllers, longitudinal dynamics controllers, crash consequence alleviation systems, longitudinal controllers, distance controllers and/or the like. These systems have their own warning thresholds and/or intervention thresholds, wherein an actual state of the motor vehicle is usually compared with a desired state, and the intervention is made in the driving dynamics and/or a warning is issued to the driver based on an existing deviation that exceeds corresponding premises. To this end, existing warning thresholds and/or intervention thresholds of the respective driver assistance system can be adjusted as a function of the evaluation parameter, in particular so as to enable a faster and better response to the ascertained diminished alertness of the driver. Driving safety can advantageously be elevated in this way.
[0018] Another exemplary embodiment of the method includes that the warning threshold and/or intervention threshold can advantageously also be adjusted as a function of the upper threshold that is present anyway, or, as an alternative, advantageously be adjusted independently of the upper threshold as a function of the adjustment threshold.
[0019] The various aspects of the present disclosure is also achieved by means of a motor vehicle. The motor vehicle is set up, designed, constructed and/or outfitted with software for implementing a method described above. This yields the advantages described above.
[0020] A person skilled in the art can gather other characteristics and advantages of the disclosure from the following description of exemplary embodiments that refers to the attached drawings, wherein the described exemplary embodiments should not be interpreted in a restrictive sense.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
[0022] FIG. 1 shows a flowchart for a method for assisting the driver of a motor vehicle.
DETAILED DESCRIPTION
[0023] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
[0024] FIG. 1 shows a schematic progression of a method for supporting the driver of a motor vehicle. In 1 , a desired driver behavior is ascertained for the driver of a motor vehicle. The desired driver behavior is described by a driver behavior parameter.
[0025] In one example, the desired driver behavior parameter is determined based on driver assistance systems already present in the motor vehicle anyway, especially driving dynamics controllers and/or navigation systems. In one example, this further takes place as a function of a given situation, for example straight line travel on a freeway, cornering on a country road, city driving, traffic flow, e.g., a traffic jam and/or free-flowing traffic and/or the like. In particular, a situation analysis is performed. For example, a division into situational classes can take place, which is kept available in a memory device of the motor vehicle, and can be called up as needed. In one example, the desired driver behavior can be provided with an initial value at the start of a driving cycle of the motor vehicle. In particular, the desired driver behavior involves a driving trajectory, a braking point, an acceleration, a viewing direction, a point and/or duration for turning on a blinker in the motor vehicle, a shifting point and/or shifting time for changing gears in the motor vehicle, a speed, in one example, a speed that depends on a traffic regulation, a driver reaction by the driver during the partially automated and/or automated operation of the motor vehicle and/or the like.
[0026] In 3 , an actual driver behavior is determined for the driver of the motor vehicle, in one example, through measurement, for example, via sensors. Further, the actual driver behavior is compared with the desired driver behavior in the 3 . Depending on the actual driver behavior, an actual driver behavior parameter that describes the later is determined
[0027] In a first comparison 5 , a deviation of the actual driver behavior from the desired driver behavior, i.e., of the actual driver behavior parameter from the desired driver behavior parameter, is determined, and this deviation is compared with a first threshold value. In one example, the deviation involves the amount by which the desired driver behavior parameter differs from the actual driver behavior parameter. The difference between the actual driver behavior parameter and desired driver behavior parameter is calculated, wherein the amount of this difference yields a deviation parameter, which is compared with the first threshold during the first comparison 5 .
[0028] In a case where the deviation parameter exceeds the first threshold value, the sequence branches into 7 . An error counter is raised in 7 .
[0029] In a case where the deviation parameter remains below the first threshold value, the sequence branches into 9 , in which the error counter is lowered.
[0030] The blocks 7 and 9 both converge into 11 .
[0031] A change in the error counter over time is determined in 11 . To this end, an evaluation parameter describing this change over time is determined.
[0032] The block 11 converges into a second comparison 13 .
[0033] The second comparison 13 prescribes an upper threshold value for the evaluation parameter. In a case where the evaluation parameter exceeds the upper threshold value, the sequence branches into 15 .
[0034] Based on 15 , it can be ascertained that the driver of the motor vehicle is unable to perform his or her driving task. The block 15 can advantageously be used to warn the driver. Alternatively or additionally, other assistance systems, for example lane departure warning systems, driving dynamics controllers and/or the like can be adjusted with the block 15 . In one example, warning and/or intervention thresholds for intervening in the driving dynamics of the motor vehicle and/or warning the driver of the motor vehicle can be changed, especially lowered, thereby enabling a response by the driver assistance systems that is faster and adjusted to the diminishing alertness of the driver. Alternatively or additionally, another comparison can be provided before or after the second comparison 13 , which compares the evaluation parameter with a warning threshold and branches to subsequently warning the driver and/or with an adjustment threshold and branches to subsequently adjusting the warning thresholds and/or intervention thresholds of the assistance systems.
[0035] The block 15 branches back to 1 , so that the method is implemented cyclically, wherein the error counter can be cyclically raised or lowered in blocks 7 , 9 . If necessary, a cycle time can exhibit a sensible length, e.g., 5-10 seconds.
[0036] In a case where the evaluation parameter lies below the upper threshold value, the second comparison 13 branches into a third comparison 17 .
[0037] The third comparison 17 stipulates a lower threshold value, and compares the evaluation parameter with it. In a case where the evaluation parameter lies below the lower threshold value, the third comparison branches into 19 . The block 19 determines that the driver is able to perform his or her driving task, and also converges into 1 .
[0038] In a case where the evaluation parameter exceeds the lower threshold value, the third comparison 17 branches into 21 . The block 21 adjusts the desired driver behavior parameter of 1 . This advantageously makes it possible to reduce the deviation parameter, wherein an adaptation can advantageously be made to the respective, in one example, sporty or defensive, driver behavior exhibited by the driver of the motor vehicle. Alternatively or additionally, the first threshold value can be adjusted for the deviation parameter of the first comparison 5 . As a result, the method can advantageously be adjusted to a control quality of a so-called man-in-the-loop control circuit. The first threshold value can be reduced for especially precisely driving motorists. The first threshold value can advantageously be raised for somewhat less precisely driving motorists.
[0039] Alternatively or additionally, the desired driver behavior parameter and/or the first threshold value can also be adjusted and/or initialized and/or reset as a function of an operator parameter or operator input of the motor vehicle driver. In one example, the latter can enter that he or she feels fit and/or can prescribe various driver traits, especially sporty or defensive and/or the like.
[0040] In particular, the actual driver behavior parameter is acquired by means of environmental sensors and/or digital maps, wherein in one example, a situation analysis is performed, during which the anticipated desired driver behavior parameter is determined Driver assistance systems already present in the motor vehicle anyway, in particular autonomous longitudinal and/or transverse controllers, can advantageously be used to supply data for ascertaining the desired driver behavior parameter, especially planned trajectories and/or speed presets, in particular also when these assistance systems have been deactivated, wherein the latter advantageously continue to supply data in the background.
[0041] Given sustained deviations between the desired driver behavior parameter and actual driver behavior parameter, i.e., a sustained deviation parameter, it can alternatively or additionally be assumed that the driver of the motor vehicle exhibits another driving style. This can advantageously be recognized by means of the evaluation parameter, if the latter lies between the upper and lower threshold value, at which the advantageous adaptation takes place. The evaluation parameter denotes a change over time, and through comparison with the lower threshold value and/or upper threshold value and/or warning threshold and/or adjustment threshold can be used to advantageously react and potentially issue danger warnings and/or readjust or adapt the driver assistance systems.
[0042] In order to evaluate the desired driver behavior by comparison to the actual driver behavior, in one example, a reaction time of the driver can be evaluated based upon events transpiring in road traffic. In particular, it is possible to determine when the driver himself or herself starts to apply the brakes after environmental sensors have detected the braking of another vehicle, in particular a vehicle in front. The deviation parameter can advantageously be ascertained here as well. In one example, if the driver always reacts very late and abruptly to changing situations, the adaptation can advantageously take place, during which a so-called baseline can be adjusted.
[0043] Alternatively or additionally, the viewing direction of the driver can also be evaluated, in one example, via an inwardly directed camera, wherein a comparison is made with the traffic situation, making it possible to determine a desired viewing direction for the driver as a desired behavior parameter. In particular, the system expects that, when a vehicle in front brakes, the driver also looks forward. In particular, when vehicles that have just started to move over to their own lane are being passed at a higher speed, it can also be evaluated whether the driver is here directing his view toward the side lane. Viewing directions that deviate from this desired driver behavior can advantageously be included in the evaluation parameter.
[0044] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims and their legal equivalents.
|
A method for assisting the driver of a motor vehicle is provided. The method includes prescribing a desired driver behavior parameter that describes a desired driver behavior, determining an actual driver behavior parameter that describes an actual driver behavior, and determining a deviation parameter that describes a deviation between the desired driver behavior parameter and the actual driver behavior parameter. The method also includes prescribing a first threshold value for the deviation parameter, raising an error counter if the deviation parameter exceeds the first threshold value, and lowering the error counter if the deviation parameter falls below the first threshold value. The method includes determining an evaluation parameter that describes a change in the error counter over time, prescribing a lower threshold value for the evaluation parameter, and initiating a reaction that affects the behavior of the motor vehicle and/or driver if the evaluation parameter exceeds the lower threshold value.
| 6
|
FIELD OF THE INVENTION
[0001] The invention pertains to devices for collecting vital sign and other data from a subject and, more particularly, to a computer pointing device having built-in and attachable measurement sensors for collecting vital sign data and a system for processing, storing, and dispersing the information collected.
BACKGROUND OF THE INVENTION
[0002] Many people suffer from medical conditions that require periodic monitoring of a health-related parameter related to their bodies. For example, diabetics typically measure blood glucose levels several times throughout the day. Hypertensive people monitor their blood pressure to ensure that it stays within a safe range. Other physical conditions may require periodic monitoring of other physical parameters.
[0003] While many devices exist for use by individuals to self-monitor a required parameter, the accuracy of the monitoring may be less than optimum. This may be due to factors such as inaccuracy inherent in inexpensive, “home” type monitoring equipment or, in other cases, lack of skill by the individual in performing the measurements. In addition, record keeping, that is recording the readings obtained from measurements is sometimes inadequate. When record keeping is poor, a physician or other trained licensed medical personnel may not have the necessary historical data to diagnose or evaluate the medical condition of the individual or to prescribe treatment of a medical condition.
[0004] In addition, even when an individual keeps good records of accurate measurements, getting that data to more than one medical practitioner becomes problematic. Even as we enter the age of paperless medical records, there is rarely any way for an individual to enter data directly into the system where it may readily be disseminated to multiple practitioners and/or institutions.
DISCUSSION OF THE RELATED ART
[0005] U.S. Pat. No. 7,335,163 for COMBINED COMPUTER MOUSE AND BLOOD PRESSURE SPHYGMOMANOMETER, issued Feb. 26, 2008 to Phillip L. Lam et al. provides a device that combines a well-known computer accessory with a blood pressure measurement system. Measurements made with the LAM et al. mouse may be recorded directly in a computer or other electronic device to which the mouse is electrically connected. The blood pressure data may be stored and averaged or otherwise analyzed by the attached computer using software.
[0006] This patent neither teaches nor suggests the novel computer pointing device having medical monitoring features and the attending system of the present invention.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention there is provided a computer pointing device commonly called a mouse that, in addition to functioning as a computer mouse of the prior art, combines a sphygmomanometer, a thermometer, and at least a glucometer. A built-in USB or similar interface allows other stand-alone measurement devices to be connected to the novel mouse, the measurements made by the devices being processed along with blood pressure and/or blood glucose readings from the novel mouse.
[0008] A general purpose computer or a dedicated computer-like appliance is connected to the mouse and receives, stores, and processes data relating to measurements made by the mouse or an attached device. Data may be transmitted from the computer to a central data facility where it may be made available to authorized medical personnel and/or institutions.
[0009] It is, therefore, an object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse.
[0010] It is another object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse having a data port allowing attachment of external measurement devices.
[0011] It is an additional object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse having a data port implemented as a USB port.
[0012] It is a further object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse that may be connected to a local controller in the form of a computer or dedicated appliance.
[0013] It is a still further object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse wherein medical data collected thereby may be stored and/or analyzed at a local controller.
[0014] It is yet another object of the invention to provide a medical data collection device incorporated into a form such as a computer mouse wherein medical data from a local controller may be transmitted to a remote site and may available to authorized medical practitioners or other authorized users of such data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0016] FIG. 1 a is a front, perspective, schematic view of a computer pointing device having a sphygmomanometer included within;
[0017] FIG. 1 b is a detailed perspective view of a tunnel portion of the mouse of FIG. 1 a;
[0018] FIG. 1 c is a front, perspective, schematic view of the computer pointing device of FIG. 1 a with exterior cover removed;
[0019] FIG. 2 is a rear, perspective, schematic view of the computer pointing device of FIG. 1 ;
[0020] FIG. 3 is a side, perspective, schematic view of a glucometer adapted to be attached to the computer pointing device of FIG. 2 ;
[0021] FIG. 4 is a simplified system block diagram of a local portion of the system of the invention;
[0022] FIG. 5 is screen shot of a typical display of data gathered by the computer pointing device of FIG. 1 a at a computer system attached thereto; and
[0023] FIG. 6 is a simplified, pictorial representation of the data collection, storage, and dispersal system in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The present invention provides an apparatus for collecting vital sign information from a human subject incorporated in a computer pointing device such as a computer “mouse”. The mouse is adapted to communicate with a computer or other electronic appliance adapted to receive data representative of a physical parameter collected from the mouse, store the data, optionally perform mathematical manipulation or analysis of the data, and to transmit raw and/or processed data to a remote site.
[0025] Referring first to FIGS. 1 a , 1 b , and 1 c , there are shown a front, perspective, schematic view of a computer mouse 100 having a built-in sphygmomanometer, not specifically identified, a detailed perspective view of a tunnel 108 portion of the mouse of FIG. 1 a , and a front, perspective view of computer mouse 100 but with an outer cover removed, respectively. Mouse 100 resembles a well known mouse of the prior art with the exception of an opening 102 in a housing 104 forming a portion of the upper portion 106 of mouse 100 . Opening 102 defines the outer end of a substantially cylindrical tunnel 108 within housing 104 that is sized and configured to circumferentially surround a finger, not shown, of a user of mouse 100 .
[0026] The inner wall of substantially cylindrical tunnel 108 includes an inflatable structure 110 (e.g., an airbag) that is adapted to selectively expand inwardly to impose pressure on a finger inserted into substantially cylindrical tunnel 108 . Inflatable structure 110 is connected to a mechanism 112 that selectively inflates and deflates inflatable structure 110 upon command thereto. This mechanism typically consists of a small electrically-driven compressor or pump 114 connected to inflatable structure by tubing 116 or another suitable conduit, not shown. Such mechanisms are believed to be well known to those of skill in the art and are not further described herein.
[0027] Mouse 100 features such as a tracking element, not shown, and one or more switches 118 .
[0028] A cable 120 connects mouse 100 to a computer or other appliance 122 ( FIG. 4 )
[0029] It is well known to those of skill in the art to use a sphygmomanometer to also measure pulse rate and such a feature is included in the sphygmomanometer forming a part of mouse 100 . In addition, additional sensors, not specifically identified, in or proximate tunnel 108 may be used to read body temperature, pulse oxygen levels, skin resistance, or other measureable body parameters. An EEG subsystem could also be provided. Consequently, the invention is not limited to the particular body parameters chosen for purposes of disclosure but is intended to include any additional body parameters measureable at the finger of a user of mouse 100 . Possible additional auxiliary sensors include, but are not limited to serum cholesterol, blood lipids, urine sugar and A1C hemoglobin.
[0030] Referring now also to FIG. 2 , there is shown a rear, perspective, schematic view of mouse 100 . An optional scrolling wheel 124 is disposed on a side of mouse 100 . It will be recognized that switches 118 and scrolling wheel 124 form no part on the invention and are included only to illustrate features often found on computer pointing devices such as mouse 100 . Consequently, the invention is not changed by the absence or presence of features such as, but not limited to switches 118 and scrolling wheel 124 .
[0031] A USB connector 126 is disposed on a rear edge of mouse 100 . USB connector 126 is adapted to optionally receive auxiliary measurement devices, for example a glucometer 128 ( FIG. 3 ). As the medical condition of each potential user of the system of the present invention may vary, the inclusion of USB connector 126 allows a user to add measurement devices pertinent to his or her medical condition and consequent need for particular data measurements.
[0032] Referring now also to FIG. 3 , there is shown a perspective, schematic view of a glucometer 128 having a USB connector 130 adapted to be received in USB connector 126 on mouse 100 . Glucometer 128 is similar to stand alone glucometers of the prior art, not shown, and is equipped with a slot to receive a test strip 134 . Test strip 134 forms no part of the invention and is included only to show a typical operating configuration of glucometer 128 . Glucometer 128 may further optionally contain one or more controls (typically buttons) 136 to performs any necessary setup function, for example but not limited to matching a control number, not shown, of a particular batch, not shown, of test strips 134 to glucometer 128 when required. Glucometer 128 may optionally be provided with a display 132 .
[0033] While glucometer 128 is shown for purposes of disclosing auxiliary measuring devices attachable to mouse 100 via USB connector 126 , it will be recognized that other measurement devices may be contemplated. The invention is not, therefore, considered limited to the auxiliary glucometer 128 chosen for purposes of disclosure. Rather, the invention includes any and all auxiliary instruments designed to measure a human body parameter.
[0034] Referring now also to FIG. 4 , there is shown a simplified schematic system block diagram of a local portion of the overall system of the present invention, generally at reference number 150 . Mouse 100 having a USB connector 126 is shown adjacent a plurality of auxiliary measurement devices 152 a , 152 b . . . 152 n . While devices 152 a , 152 b , . . . 152 n are shown schematically as having a built-in USB connector 160 a , 160 b . . . 160 n adapted for selective interconnection to USB connector 126 on mouse 100 , it will be recognized that auxiliary measurement devices 152 a , 152 b , . . . 152 may be in other form factors, not shown, that may be interconnected to USB port 126 of mouse 100 by a cable, not shown, having a compatible USB connector, not shown, at a distal end thereof. A desired one of auxiliary measurement devices 152 a , 152 b , . . . 152 n is selectively plugged into USB connector 126 of mouse 100 as shown by arrow 162 . Glucometer 128 ( FIG. 3 ) is an example of auxiliary measurement devices 152 a , 152 b . . . 152 n.
[0035] Cable 120 of mouse 100 is shown connected to computer 122 . As used herein in, the term computer is intended to apply to any general purpose computer or dedicated electronic appliance having the capability to interconnect to mouse 100 and an appropriate communications interface 154 . Computer 122 is assumed to include all internal and external systems, sub-systems, operating system(s), application software, and peripheral devices, none of which is specifically identified, necessary to perform any necessary control or computational processes. For example, computer 122 may include an additional human interface such as a keyboard and a monitor, neither specifically identified.
[0036] A communications interface 154 is provided to communicate data from computer 122 to a remote site. For purposes of disclosure it is assumed that all electronic communication is via a communications link 156 to the Internet, shown schematically at reference number 158 .
[0037] Referring now to FIG. 5 , there is shown a typical screen displayed on the monitor, not specifically identified, of computer system 122 , generally at reference number 170 . A number of data display areas are shown on screen 170 . Screen 170 has a number of display areas dedicated to presentation on a single aspect of the data gathered at local system 150 , primarily by mouse 100 and ancillary measurement instruments attached thereto by USB connector 126 .
[0038] For example, display regions 172 and 174 display, respectively a waveform associated with ventricular and arterial blood pressures. Controls 176 and 178 , associated with display regions 172 , 174 respectively, control the display parameters thereof.
[0039] A time scale 180 displays the time (in seconds) during which the waveforms in display regions 174 , 174 have been acquired. A control 182 allows selection of a specific time period to be displayed.
[0040] An optional comment field 186 is provided for adding descriptive information to the data stored from a particular measurement Control 188 is provided to allow addition of comment 186 .
[0041] Temperature 190 , pulse 192 , and blood sugar 194 readings are displayed in respective display regions at the right hand side of screen 170 .
[0042] Other controls, not specifically identified, believed to be well known to those of skill in the art are provided to control various display parameters and functions.
[0043] It will be recognized that numerous display layouts may be conceived and provided to display measurements at local system 150 . Consequently, the invention is not considered limited to the specific layout or to the data elements displayed on screen 170 provided for purposes of disclosure. Rather, the invention includes any screen layout and mix of measured values.
[0044] Referring now also to FIG. 6 , there is shown a simplified, pictorial diagram of the system for acquiring, storing, transmitting, and dispersing information in accordance with the invention, generally at reference number 200 .
[0045] A central facility 202 contains processors 204 , bulk data storage units 206 , and communications controllers 208 . Central facility 202 is adapted to receive and store uploaded data from numerous user local systems 150 , only one of which is shown, via communications links 156 and 210 from each of the local systems 150 .
[0046] Secure data communication is maintained on communications links 156 , 210 by a security device, shown schematically at reference number 212 and associated with communications links 156 and 210 . Data security device 212 may be implemented using a wide range of different protocols and security arrangements believed to be well known to those of skill in the electronic communication arts. For purposes of disclosure, data security device 212 provides a secure sockets layer (SSL) security protocol, specifically and AES-256 bit implementation, to ensure the security of data to and from a local system 150 and the communications controller 208 at central facility 202 . SSL is believed to be widely understood by those of skill in the art and, consequently, is not further discussed herein. However, the invention is not considered limited to the SSL method used for purposes of disclosure. Rather, the invention includes the use of either no data security system or any known or yet to be implemented data security system.
[0047] Data, not shown, from each local system 150 is transmitted to central data management facility 202 where it is stored (e.g., warehoused) with other data for each identified user. Uploaded data for each individual may be processed, for example, averaged or otherwise statistically analyzed. It is envisioned that either raw data or, in order to conserve storage space, various summaries of the data may be stored.
[0048] Authorized Data Consumers (ADCs), typically medical practitioners 214 a , research facilities such as university research facility 214 b , outpatient clinics 214 c , government agencies, for example, Medicare administration 214 d , are able to communicate with remote data management facility 202 and, when properly authorized, obtain data for one or more individuals for whom data has been uploaded, stored, summarized and possibly analyzed.
[0049] It is anticipated that the system of the invention would be a privately run service to which individuals could subscribe. All or portions of local system 150 could be either purchased outright by a subscriber or leased from the entity providing the service.
[0050] Persons wishing to store data would subscribe and obtain necessary portions of local system 150 . Each person would be responsible for determining what medical data was to be gathered, with what frequency measurements should be made, time of measurements, etc. Such determinations would presumably be made in consultation with competent, probably licenses, medical professionals.
[0051] Subscription fees may be determined by the number, frequency, and/or complexity of tests performed at local system 150 . Additional charges could be imposed based upon the amount of data being stored or other similar factors.
[0052] ADCs 214 a . . . 214 n may, upon proper authorization, be allowed free access to the data. In alternate embodiments, ADCs 214 a . . . 214 n may be charged either a subscription fee or a pay per use charge to obtain information from central data management system 202 .
[0053] System 200 is advantageous in that individuals may monitor certain medical parameters at home using reliable equipment that is as close to fool proof as possible. Features in either local or remote software may be provided to flag suspicious readings so that they may be repeated if they fail to meet a predetermined criteria. If repeated measurements are suspect, the user may be directed to a medical professional (e.g., doctor's office, clinic, etc.) to have a reading verified.
[0054] The ability to routinely monitor health related values from home alleviates the need for frequent trips to a doctor's office, emergency room, clinic, etc., thereby freeing those resources for more critical care related utilization. Further, it saves significant amounts of time for the user who avoids the time overhead and expense of transportation (public or private).
[0055] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0056] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
|
A computer pointing device commonly called a mouse that, in addition to functioning as a computer mouse of the prior art, combines a sphygmomanometer and a thermometer. A glucometer or other specialized measurement devices may be attached via a built-in USB or similar interface. Data (e.g., blood glucose readings) from such attached instruments may be processed along with blood pressure, temperature, pulse, etc. A general purpose computer or a dedicated computer-like appliance is connected to the mouse and receives, stores, and processes data relating to measurements made by the mouse or an attached device. Data may be transmitted from the computer to a central data facility where it may be made available to authorized medical personnel and/or institutions.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Non-Provisional application Ser. No. 10/778,572, filed Feb. 13, 2004, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] Current natural gas reserves are often situated far from world markets. Although it is possible to transport the natural gas, in many cases it is preferred to convert the natural gas fields in situ into more readily transportable products such as synthetic fuels, methanol or dimethyl ether. The conversion processes generally consume very large amounts of oxygen and produce excess steam. Background for this field is to be found in “Oxygen Facilities for Synthetic Fuel Projects”, by W. J. Scharle et al., Journal of Engineering for Industry, November 1981, Vol 103, pp. 409-417, in “Fundamentals of Gas to Liquids” January 2003, The Petroleum Economist Ltd, and in EP-A-0748763.
[0003] It is not always possible to construct an air separation unit close to the site of the conversion process, for example for environmental or economic reasons. In this case, the steam generated is sent via a pipeline to the air separation unit site and there it is expanded in a turbine coupled to the main compressor of the air separation unit.
[0004] However, the cost of such steam pipelines is prohibitive since the steam has to be maintained at a high temperature to prevent condensation.
[0005] In some cases, there may be a number of processes, each producing excess energy in the form of steam or another hot gas. There may be insufficient energy available on the site of the process to justify exporting that energy and the steam or other hot gas may be vented to the atmosphere. Furthermore, the individual processes may each produce a different grade of steam, such that the two grades of steam cannot be sent to a single steam turbine.
SUMMARY
[0006] It is an object of the present invention to provide a process for separating air using the energy generated by a process remote from the air separation unit.
[0007] This invention provides an integrated process and gas treatment process wherein at least one first pressurized gas derived from a first process at a first site is expanded. Using the work generated by the expansion of at least one pressurized gas, a first gas compressor at the first site is driven, operates, and removes compressed gas from the first gas compressor. At least part of the compressed gas from the first gas compressor is sent to a gas treatment unit located at a remote second site. At least part of the compressed gas sent from the first site to the second site is treated in the gas treatment unit. At least one fluid from the gas treatment unit is removed and at least part of the fluid removed from the gas treatment unit is sent to the first site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:
[0009] FIG. 1 illustrates one embodiment of the current invention, which includes an integrated process and air separation unit;
[0010] FIG. 2 illustrates a second embodiment, which includes an air separation unit integrated with two integrated processes; and
[0011] FIG. 3 illustrates a third embodiment with an integrated process and air separation unit.
[0012] The figures are not to scale.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The term “partly pressurized” implies that the oxygen or nitrogen streams may for example be pumped to a pressure less than their required pressure and then vaporised at the second site before entering the pipelines. Compressors at the first site subsequently compress the nitrogen and oxygen to their required final pressures, if needed.
[0014] FIG. 1 shows an integrated process and air separation unit. The integrated process unit 31 is located at a first site 1 and may for example be a GTL unit, for example comprising a Fischer Tropsch unit, a methanol production unit, a DME production unit, a fuel combustion unit such as a gas turbine or any unit producing directly or indirectly steam or another hot gas.
[0015] The term “process unit” implies that a process takes place at some location and at some time within the unit. However, the unit itself does not necessarily operate according to a process, which is globally exothermic.
[0016] The steam or other hot gas 39 is expanded in a turbine 33 (which may form part of process unit 31 ) located at the first site 1 and work from the turbine is transferred via coupling to an air compressor 5 . In this example, the air compressor 5 compresses only air 7 to be sent to the air separation unit 21 . The compressed air 19 is compressed to a pressure above 8 bars, preferably above 12 bars and is sent to the air separation unit 21 at a second site 2 at least 1 km away. It is nevertheless conceivable that compressed air from the air compressor 5 could also be sent elsewhere, i.e., to another air separation unit.
[0017] Compressed air may also be sent to the air separation unit 21 from an air compressor 25 located at the second site 2 .
[0018] Air to be separated in the air separation unit 21 is purified in a purification unit at the second site and all the air streams sent to the air separation unit 21 at the second site from the purification unit at the second site are at pressures less than 50 bars.
[0019] A product gas 37 (which may be replaced by a product liquid) coming from the air separation unit is also sent to another pipeline running at least substantially parallel to the air pipeline over at least part of its length, thereby saving civil engineering costs. This gas, which may be nitrogen, oxygen or argon, is unpressurized, partly pressurized or pressurized. Where the gas is unpressurized or partly pressurized, it may be compressed in a compressor 47 coupled to the turbine 33 at the first site. The gas may then be used at the first site and may for example be used in the process.
[0020] FIG. 2 shows an air separation unit 21 integrated with two integrated processes. The first process unit 31 is as described above with reference to FIG. 1 . The further process unit 31 A is located at a third site 3 , at least 1 km from the second site, where the air separation unit 3 is located and, preferably, at least 1 km from the first site. However, the further unit 31 A may be adjacent to the first site.
[0021] The further process unit 31 A may operate according to the same process as the first unit 31 or according to a different process.
[0022] The unit 31 A produces steam or another hot gas 39 A, which is expanded in turbine 33 A. Gases 39 and 39 A may both be steam but the gas 39 A may be steam having the same or different properties, i.e., the same or a different pressure as the gas 39 and/or the same or a different temperature as the gas 39 .
[0023] Air compressor 5 A driven by turbine 33 A supplies air 19 A only to the air separation unit via pipeline. The air 7 A compressed by compressor 5 A is compressed to a pressure above 8 bars, preferably above 12 bars.
[0024] Additionally, as in FIG. 1 , there may a dedicated air compressor at the second site 2 .
[0025] Preferably, the pipelines 19 , 19 A, and the compressors 5 and 5 A supply the air to the second site 2 at substantially the same pressure so that only a single purification unit within the air separation unit 21 is necessary. This may mean that the compressors 5 and 5 A compress the air to substantially the same pressure, if the pressure losses within the pipelines are substantially the same. Alternatively, the compressors 5 and 5 A may compress the air to different pressures but the air arrives at the air separation unit at substantially the same pressure from both pipelines due to a judicious choice of the pipeline diameters and/or lengths and/or the use of an expansion means, such as a valve.
[0026] If several purification means are provided, the air supplied by the compressors 5 and 5 A may arrive at the second site at different pressures (due to different pressures at the compressor outlets and/or different pressure drops within the pipeline systems). In this case, the air pressures may be selected or modified at the second site to correspond to pressures of different columns of the air separation unit. For example, one air stream may be purified at the pressure of the high pressure column of the air separation unit whereas another air stream may be purified at the pressure of an intermediate or low pressure column of the air separation unit.
[0027] A product gas 37 A coming from the air separation unit is also sent to another pipeline running substantially parallel to the air pipeline for air 19 A over at least part of its length. This gas, which may be nitrogen, oxygen or argon, is unpressurized, partly pressurized, or pressurized. Where the gas is unpressurized or partly pressurized, it may be compressed in a compressor coupled to the turbine 33 A at the third site. The gas may then be used at the third site, for example in the process or another process.
[0028] Alternatively, the pipeline for air 19 A may run substantially parallel to the pipeline for air 19 over at least a part of its length or may feed into that pipeline 19 (or vice versa depending on where the sites 1 , 2 , 3 are).
[0029] Similarly, the pipeline for gas 37 A may run substantially parallel to the pipeline for gas 37 over at least a part of its length or may feed into that pipeline 37 (or vice versa depending on where the sites are) if the gases have substantially the same purity or can be mixed to form a mixture having a required composition.
[0030] At least one fluid produced by the air separation unit may be sent to the first or third site or both.
[0031] The third site 3 may be contiguous with the second site 2 , less than 1 km from the second site, or at least 1 km from the second site, and/or the third site 3 may be contiguous with the first site 1 , less than 1 km from the first site, or at least 1 km from the first site.
[0032] The air separation unit may be of any known type. Ideally, there should be no air compressor 25 located at the second site to produce air for the air separation unit. All the feed air should come from other sites. One example of an air separation process well suited to this application is that of FIG. 1 of EP-A-0504029, where all the air is compressed to a high pressure using a single compressor.
[0033] It will be appreciated that a first stream of air may be compressed using work from a first expansion step (such as a steam turbine expansion) and a second stream of air may be compressed using work from a second expansion step (such as a gas turbine expansion), the first and second air streams may be mixed, possibly after pressure equalisation and sent from the first site to the second site.
[0034] FIG. 3 shows an integrated process and air separation unit.
[0035] The integrated process unit 31 is located at a first site 1 and may for example be a GTL unit, for example comprising a Fischer Tropsch unit, a methanol production unit, a DME production unit, a fuel combustion unit such as a gas turbine or any unit producing directly or indirectly steam or another hot gas.
[0036] The term “process unit” implies that a process takes place at some location and at some time within the unit. However the unit itself does not necessarily operate according to a process, which is globally exothermic.
[0037] The steam or other hot gas 39 is expanded in a turbine 33 (which may form part of process unit 31 ) located at the first site 1 and work from the turbine is transferred via coupling to an air compressor 5 . In this example, the air compressor 5 compresses only air 7 to be sent to the air separation unit 21 . The compressed air 19 is compressed to a pressure above 8 bars, preferably above 12 bars and is sent to the air separation unit 21 at a second site 2 at least 1 km away. It is nevertheless conceivable that compressed air from the air compressor 5 could be sent elsewhere, for example to another air separation unit.
[0038] Compressed air is sent to the air separation unit 21 from an air compressor 25 located at the second site 2 . The air compressor 25 is driven by a turbine 33 B, which expands gas 32 B from a process unit 31 B at the second site. Air to be separated in the air separation unit 21 is purified in a purification unit at the second site and all the air streams sent to the air separation unit 21 at the second site from the purification unit at the second site are at pressures less than 50 bars.
[0039] A product gas 37 (which may be replaced by a product liquid) coming from the air separation unit is also sent to another pipeline running at least substantially parallel to the air pipeline over at least part of its length, thereby saving civil engineering costs. This gas, which may be nitrogen, oxygen or argon, is unpressurized, partly pressurized or pressurized. Where the gas is unpressurized or partly pressurized, it may be compressed in a compressor 47 coupled to the turbine 33 at the first site. The gas may then be used at the first site and may for example be used in the process.
[0040] It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.
|
Integrated air separation units with a petrochemical process. This invention provides an integrated process and gas treatment process wherein at least one first pressurized gas derived from a first process at a first site is expanded. Using the work generated by the expansion of at least one pressurized gas, a first gas compressor at the first site is driven, operates, and removes compressed gas from the first gas compressor. At least part of the compressed gas from the first gas compressor is sent to a gas treatment unit located at a remote second site. At least part of the compressed gas sent from the first site to the second site is treated in the gas treatment unit. At least one fluid from the gas treatment unit is removed and at least part of the fluid removed from the gas treatment unit is sent to the first site.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a latch mechanism used in manually moving and locking various objects.
2. Description of Related Art
In an image forming apparatus, a user often needs to gain access to the various components within the image forming apparatus for repairing, replacing, cleaning, or other service related matters. Thus, image forming apparatus are preferably constructed in a modular configuration in which components are latched into position but are capable of being unlatched for access to the components.
SUMMARY OF THE INVENTION
The present invention describes a latch mechanism which may be used wherever a large motion and large force is required in a small area by use of manual power. However, the latch mechanism will be described as applied to just one possible structure having heavy components which need to be moved manually, i.e. components of an image forming apparatus. Also, the latch mechanism allows the components being secured to be unlocked and separated so that a user may access the components and the parts in between and inside each component.
The latch mechanism in one possible configuration comprises a first member, a second member pivotably connected to the first member, and a handle connected to the second member. A latch mechanism selectively maintains a first component in a fixed position relative to a second component. The latch mechanism include a first member for selective attachment to the first component; and a second member for selective attachment to a second component and pivotally attached to the first member. The first and second members assume a locked position when the first and second members are substantially aligned and assume an unlocked position when the first and second members are traverse to each other. A handle is pivotally connected to the second member. A link member is pivotally connected at one end to the second member and pivotally connected at an opposite end to the handle. The link member assumes a first position when the handle is moved to a corresponding first handle position to have the link member positioned overcenter with respect the first and second members to brace the first and second members in a locked position. The link member also assumes a second position when the handle is moved to a corresponding second handle position to move the link member traverse or undercenter to the second member to allow the first and second members to pivot relative to each other. The link member maintains the first and second members in the locked position until the handle is moved from the first handle position to the second handle position. A link member, which is attached to the second member and the handle, aids in locking the two members and reducing the pivotal movement between the two members. Furthermore, a ball joint is attached to one end of the first member and a bracket is attached to one end of the second member. The ball joint allows the latch mechanism to pivot along the X axis, and the bracket allows the link mechanism to pivot along the X and Y axes. A spring arrangement may also be added which pulls the link member toward a locked position.
Furthermore, in an image forming apparatus, if a user moves the pre-fuser transport into proper position before disengaging or re-engaging the xerographic towers and other components, there is a chance that this could cause damage to the prefuser transport. Therefore, a locking mechanism has been designed to require movement of the pre-fuser transport before unlatching other components such as the xerographic towers.
This invention provides a latch mechanism which may be used wherever a large motion and a large force is required in a small area by manual power.
This invention separately provides a latch mechanism which locks one or more components together securely.
This invention separately provides a latch mechanism which allows the device to unlock and lock components very quickly.
This invention separately provides a lock mechanism which reduces the likelihood of the prefuser transport and the xerographic towers from colliding due to user's failing to follow proper procedures.
This invention separately provides a lock mechanism which may be cheaply made and may be implemented in an image forming apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be described in relation to the following drawings, in which reference numerals refer to like elements, and wherein:
FIG. 1 is a top view of the image forming apparatus wherein the modular components and the latch mechanism are in a locked position.
FIG. 2 is a front view of the image forming apparatus wherein the modular components and the latch mechanism are in a locked position.
FIG. 3 is a right view of the image forming apparatus wherein the modular components and the latch mechanism are in a locked position.
FIG. 4 is a top view of the image forming apparatus wherein the modular components and the latch mechanism are in a full open position.
FIG. 5 is a front view of the image forming apparatus wherein the modular components and the latch mechanism are in a full open position.
FIG. 6 is a perspective view of the latch mechanism.
FIG. 7 is a top view of the latch mechanism in a full closed position.
FIG. 8 is a top view of the latch mechanism in a semi-open position with the first handle in a locked position and the second handle in an open position.
FIG. 9 is a top view of the latch mechanism in a full open position with the first handle and the second handle in an open position.
FIG. 10 is a top view of the locking mechanism.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1, 2 and 3 show the top, front and right view, respectively, of an image forming apparatus 100 , conventionally having modular sections, in a locked position by a latch mechanism 140 . It should be appreciated that the present invention may be used in various exemplary embodiments having various configurations, however, an explanation will be given with respect to one of many exemplary embodiments as shown in the figures discussed below.
As shown in the exemplary embodiment in FIGS. 1, 2 and 3 , the image forming apparatus 100 is conventionally configured in modular sections having a left xerographic tower 114 , a photoreceptor 118 and a right xerographic tower 122 . Conventionally, a recording medium enters the image forming apparatus 100 and moves from the left xerographic tower 114 to the photoreceptor 118 and is finally received by the right xerographic tower 122 . Each modular component ( 114 , 118 and 122 ) contains various components which assist in forming the image on a recording medium.
When a user wishes to get access within the image forming apparatus 100 shown in FIGS. 1-3, the modular components must be separated, as shown in FIGS. 4 and 5, so that the user can access the individual components within the image forming apparatus to replace, clean, fix or to perform other service related matters. A device is necessary to enable the modular components to come apart, or be separated from one another, and then placed back into a locked position. Once the modular components are placed in a locked position, it is critical that these members stay in a stationary or fixed position relative to each other, and return to their original position. Therefore, the present invention, as illustrated in FIG. 6, shows one exemplary embodiment of a latch mechanism 140 which enables the modular components to come apart and become separated from one another and also enables the modular components to move back into a locked position. This advantage along with other advantages will become more apparent during the description of the latch mechanism 140 as described below.
FIG. 6 illustrates one exemplary embodiment of a latch mechanism 140 . The latch mechanism 140 has a first member 142 and a second member 144 which are connected by a pivotable attachment member 146 which in the exemplary embodiment is a screw type device, however the pivotable attachment member 146 may be a clamp, hinge or other like members. In the exemplary embodiment, the first member 142 is pivotably attached to the right xerographic tower 122 . The first member 142 has a ball joint 148 attached at one end, but in the exemplary embodiment the ball joint 148 is attached to the end which is attached to the right xerographic tower 122 . The ball joint 148 allows the first member 142 to pivot along the X axis. The other end of the first member 142 is connected to the second member 144 and is also able to pivot along the X axis due to the pivotable attachment member 146 . In the exemplary embodiment, the second member 144 has a slot portion 150 which is able to receive the first member 142 , and also allows the first member 142 to move along the X axis.
The second member 144 is pivotably connected at the other end to a U-shaped bracket 152 . The second member 144 , and accordingly the members attached to the second member, are able to rotate along the Y axis. The U-shaped bracket is attached to an outer frame 154 portion of the image forming apparatus 100 . The U-shaped bracket 152 is attached to the second member 144 in such a manner, so that the second member 144 is able to freely rotate along the Y axis. This feature allows the user to move the right xerographic tower 122 and a pre-fuser transport (not shown) in an upward direction to gain access to the two components.
The first member 142 has a first handle 160 . In the exemplary embodiment the first handle 160 extends upwards, along the Y-axis, and is attached to the first member 142 . The second member 144 has a second handle 162 . The second handle 162 extends along the X axis, and has curved shape. It should be appreciated that the present invention may operate with one handle, but in the exemplary embodiment the latch mechanism 140 has two handles 160 and 162 . The handles 160 and 162 allow the user to move the latch mechanism 140 which accordingly moves the modular components apart as shown in FIGS. 4 and 5. Furthermore, as shown in FIG. 6, the handles 160 and 162 have a gripping member 164 attached to the handles 160 and 162 to allow the user to grip the handles with greater ease. Also, a safety cover 165 may surround the latch mechanism 140 so that user's hand or other objects do not get caught within the components of the latch mechanism 140 .
The present invention also includes a first structure, 180 located on the second handle 162 and extending upwardly, and a second structure 182 located on the bracket 152 and also extending upwardly. An elastic spring 184 is connected between the first and second structures 180 and 182 , and applies a force which pulls the second handle clockwise toward a locked position.
To unlock the latch mechanism 140 , various steps and procedures may be performed, but a description will be given according to one possible configuration of the latch mechanism 140 . FIG. 7 shows the latch mechanism. 140 in a locked position with the first and second handles 160 and 162 in a locked position. FIG. 8 shows the latch mechanism in a semi-open position with the first handle 160 in a locked position and the second handle 162 moved to an unlocked position. FIG. 9 shows the latch mechanism 140 in an open position with the first handle 160 and the second handle 162 in an open position.
A detailed explanation of the operation of the latch mechanism 140 will be given with respect to one of the exemplary embodiments as illustrated in FIGS. 7-9. In FIG. 7, the latch mechanism 140 is in a locked position, therefore allowing almost no pivotable movement. In the locked position, the first and second members 142 and 144 are substantially aligned end to end, thus forming a brace for preventing movement of the modular components. The latch mechanism 140 is held in a locked by a link member 166 which is pivotally attached to the second handle 162 by a first pivoting member 170 and pivotally attached to the second member 144 by a second pivoting member 174 . The link member 166 is over center of the second member 144 when the latch mechanism 140 is in a locked position, thus maintaining the first and second members 142 and 144 in their end to end alignment. The end of the link member 166 opposite to the end connected to the second handle 162 is connected to a slotted portion 168 on the top portion or located within the slot portion 150 of the second member 144 . When the second handle 162 is rotated, the link member 166 is able to translate along the slotted portion 168 and also pivot with respect to the first pivoting member 170 . However, in the locked position, the pivoting member 174 is pressed against one end of the slotted portion 168 , thus bracing the link member 166 between the first pivoting member 170 and the second pivoting member 174 . When the link member 166 is in the locked position, the first and second members 142 and 144 can not pivot relative to each other because the handle 162 , and thus adjust the end 171 of the link member 166 maintains its position. Furthermore, the elastic spring 184 pulls the handle 162 , and thus adjusts the end of 171 of the link member 166 towards a locked position.
FIG. 8 shows the latch mechanism 140 in a semi-open position. In this position, the second handle 162 is pivoted outwards or counterclockwise. Because the link member 166 is pivotably connected to the second handle 162 by the first pivoting member 170 , the first end portion 171 of the link member 166 which is connected to the second handle 162 is pivoted in a clockwise direction. The second pivoting member 174 at the second end portion 176 is moved along the slot portion 168 towards the outer frame 154 . In this position, the first and second members 142 and 144 are no longer braced and are capable of pivotal movement relative to each other.
FIG. 9 shows the latch mechanism 140 in a full open position with both the handles 160 and 162 and the first and second members 142 and 144 in an open position. After the second handle 162 is rotated counterclockwise until the second handle 162 is no longer able to rotate, the user is able to pull the first handle 160 to rotate the first member 142 in a clockwise direction and the second member 144 in a counterclockwise direction. As shown in FIG. 9, the first and second members 142 and 144 form a V-shape when in the full open position. It should be appreciated that the latch mechanism 140 could be configured so that the latch mechanism 140 is able to open in the opposite direction. The outer frame 154 is a static structure, thus, when the first handle 160 is being pulled to an open position, the first member 142 pulls the right xerographic tower 122 toward the outer frame 154 . As shown in FIG. 4 when the latch mechanism 140 is in an open position, the modular components 114 , 118 and 122 are pulled towards the outer frame and are separated from one another.
One of the advantages of the present invention is that the latch mechanism 140 allows the user to consume very little energy or power in order to separate the modular components or to lift the right xerographic tower along with the pre-fuser transport. The latch mechanism 140 is a manually operated two handle device and allows the user to quickly unlock and lock the modular components in less than 11 seconds. It should be noted that the latch mechanism 140 is not only useful in moving components in an image forming apparatus, but may be used wherever a large motion and large force is required in a small area with manual power. The second handle 162 is primarily used to move to link member 166 from a locked position to an unlocked position, and moves the modular components a small distance. The first handle's 160 primary purpose is to move the modular components to an unlocked position and separate the modular components from one another.
One of the problems with engaging and disengaging the xerographic towers 114 and 122 and the photoreceptor is that if the user does not follow proper procedural steps the xerographic towers 114 and 122 and the photoreceptor may collide and damage the components. Therefore, a locking mechanism 200 has been designed to solve this problem. The locking mechanism 200 , as shown in FIG. 10, generally comprises a locking fork 202 , a pivotably attachable member 204 , a pivoting pinion shaft key 206 and a spring 210 .
The locking mechanism 200 may be implemented in any type of rotary motion device to lock one or more members into a locked position. However, a description of the locking mechanism 200 will be given in relation to lock the latch mechanism 140 , which is in a locked position until the user has moved the pre-fuser transport.
The pivoting pinion shaft key 206 is attached to the second handle 162 of the latch mechanism 140 . The pivoting pinion shaft key 206 has a plurality of teeth 212 which surround the outer circumference of the pivoting pinion shaft key 206 . The locking fork 202 is pivotally attached to the second member 144 by the pivotably attachable member 204 . On one end of the locking fork 202 is a spring 210 and on the opposite end is an opening 214 . The end having the spring 210 also has a plurality of teeth 216 which are configured to engage and lock with the teeth 212 of the pivoting pinion shaft key 206 . The teeth 216 located on the fork 202 are designed to fully conform to the teeth 212 of the pivoting pinion shaft key 206 at any point of rotation of the fork 202 and pivoting pinion shaft key 206 assembly.
The end of the fork 202 opposite to that of the spring 210 has an opening 214 which is able to receive a cable 220 . The cable 220 connects the fork 202 to the pre-fuser transport (not shown). When the pre-fuser transport is moved into proper position, the cable 220 pulls the fork 202 in a clockwise direction, thus disengaging the teeth 212 of the pivoting pinion shaft key 206 from the teeth 216 of the fork 202 . Until the prefuser transport is moved, the teeth 216 of the fork 202 mesh against the teeth 212 of the pinion shaft key 206 , thus preventing pivotal movement of the handle 162 . However, once the prefuser transport is moved, the teeth 216 disengage from the teeth 212 . Therefore, the user is able to move the second handle 162 to open up the latch mechanism 140 . Unless the pre-fuser is moved into proper position, a user can not accidentally open the latch mechanism 140 and damage the prefuser transport. Furthermore, the spring 210 applies a locking force between the fork 202 and the pivoting pinion shaft key 206 producing a normally locked condition.
The pinion shaft key 206 is made from gear stock which is cheap and relatively durable. The locking member 200 allows a cheap locking device to be implemented to lock one or more devices in position.
While this invention has been described in conjunction with the exemplary embodiments outlined above, it is evident that may alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary 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.
|
A locking mechanism selectively prevents rotational movement of a handle relative to a frame. The locking mechanism includes a fork member having first and second ends and pivotally attached to the frame member at a pivot located between the first and second ends; a first locking device located at the first end of the fork member; a second locking device located on the handle and engaging the first locking device on the first end of the fork member for preventing rotational movement of the handle; an elastic member for biasing the first and second locking devices into engagement; and an attachment mechanism located at the second end of the fork member. A tension force on the attachment mechanism pivots the fork member about the pivot member to disengage the first and second locking devices and allow the handle to rotate relative to the frame.
| 8
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to door opening systems. In particular, this invention pertains to a door opening system which allows displacement by any part of the body of a user against the system to automatically unlatch and open the door. More in particular, this invention relates to a door opening system where a broad surface planar member extends in a transverse direction across the door to be opened and displacement in a unitary direction causes automatic unlatching of the door and rotation of the door in an opening mode. Still further, this invention relates to a door opening system which is mounted on opposing transverse ends to the door to be opened and to a latch lever which is actuated by movement of the planar member. Further, this invention pertains to a door opening system which includes a planar member having a predetermined contour for clearing both automatic closing devices and interference tolerances for a door knob on an inner door.
2. Prior Art
In general, door opening systems for aiding in the opening of a door are known in the art. However, some of these prior systems provide for a bar member of complicated mechanical design having a combination of elements which is expensive to manufacture and provides increased labor costs in construction.
In some of these prior art door opening systems, the opening mechanism is provided by a bar member passing in a transverse direction across the door to be opened. Such bar mechanisms do not provide a broad surface area which may be displaced in a unitary direction by any part of the body of a user to provide the necessary opening motion.
In other prior systems, the door opening mechanism is not of a predetermined contour to permit interface of the prior door opening system with automatic closing devices which are common and generally related to storm or screen doors upon which the door opening system is to be mounted.
Still further, other prior art door opening systems do not provide cut out relief sections to allow clearance of door knobs and other door hardware relating to standard construction doors.
SUMMARY OF THE INVENTION
A door opening system for releasably actuating a door latch having a displaceable latch lever and rotatably displacing a door in one motion of a user. The door opening system includes a planar member extending in a transverse direction across the door adjacent and substantially parallel to a plane of the door. Additionally, the door opening system includes a mechanism for actuating the door latch for displacing the latch lever. The actuating means is fixedly secured to the planar member and the latch lever is positionally located in contact relation therewith.
It is an object of the subject invention to provide a door opening system which aids and maintains a convenient mode of operation in the opening of door members.
Another object of this invention is to provide an improved door opening system which is utilized specifically in doors having automatic closing devices.
It is another object of this invention to provide an improved door opening system which allows the user in one motion to release the latch holding the door in a closed mode and to further rotatably displace the door to an open position.
It is a still further object of this invention to provide a safety device for users wherein during an emergency situation, the user only has to move against the door system to provide an opening mode of operation.
Another object of this invention is to provide a broad surface door opening system which protects the glass or screens formed in the door to be opened.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of the door opening system showing the system mounted to an outer door;
FIG. 2 is a sectional view of the door opening system taken along the section line 2--2 of FIG. 1; and,
FIG. 3 is a perspective view of the door opening system showing the particular component associated therewith.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1-3, there is shown door opening system 10 for aiding a user upon entry and exit through screen or storm door 12. In general, homes or other edifices have a combination of inner door 14 and an exterior screen or storm door 12 as shown in FIG. 1. A standard combination screen and storm door 12 is provided with pneumatic, hydraulic, or other type automatic closing devices 16 well known in the art, and not part of the inventive concept as is herein described. Automatic closing devices 16 generally are mounted on one end to door jam 18 and on a second end 20 to an inner surface of screen or storm door 12. As seen in FIG. 1, automatic closing device 16 extends in a transverse direction 22 and is rotationally actuatable about axis line 24 in order to permit storm door 12 to be rotated in a normal opening and closing condition. It is to be understood that door opening system 10 is applicable to existing doors 12 as may be mounted on new doors being manufactured.
Due to the fact that automatic closing devices 16 tend to provide for a closing force applied to doors 12 to which such are secured, an operator must maintain a counteracting force in order to displaceably open doors 12. As will be seen in following paragraphs, door opening system 10 provides a broad surface which allows opening of door 12 in one motion by the operator. Further, the broad surface provided by system 10 allows the operator to hold door 12 in an open position during entrance or exit while providing a minimum probability of any entanglement with hardware elements attached to door 12. Still further, system 10 allows the user to open and close doors 12 while not coming into contact with either the screens or window pane portions of doors 12. Thus, any impact loading provided by the user in the opening of doors 12 is directed against door opening system 10 and not to doors 12 per se. Door opening system 10 also provides for an emergency exit opening system whereby a user who must egress through door 12 in an expeditious manner merely displaces system 10 in one motion with a responsive opening of door 12. Utilization of door opening system 10 minimizes any necessary manipulation of latches or other locks for opening doors 12 since the displacement of system 10 by any portion of the human body results in a responsive opening of door 12.
In overall concept, door opening system 10 is utilized for releasably actuating door latch 26 which is any one of a standard number of latch mechanisms well known in the art. Door latch 26 as is the standard case, includes displaceable latch lever 28 which is contacted by the movement of system 10 for opening door latch 26 and allowing door 12 to be opened in one motion of the user. One of the basic components of door opening system 10 is planar member 30 extending in both transverse direction 22 and vertical direction 32. As can be seen in FIGS. 1 and 2, planar member 30 extends in transverse direction across door 12 in a manner such that system 10 lies adjacent and substantially parallel to a plane of door 12. Of importance, inner face 34 of planar member 30 is provided with a broad surface area in order to allow the user to have a wide contact force area for displacement of system 10. The broad surface area is of importance in that such does protect screen or storm door 12 from impact and allows initial force loading to be applied to system 10 without the necessity of the user impacting or otherwise touching door 12.
Planar member 30 is generally mounted approximately one-half the vertical distance of the extension of door 12. With a broad surface area to be contacted by the user, such allows operators of varying heights to easily accomplish the opening procedure.
As can be seen from FIGS. 1 and 3, planar member 30 is generally U-shaped in contour and includes slot 36 formed therethrough. Slot 36 passes in transverse direction 22 and generally extends from first end 38 in an open contour fashion as is more specifically seen in FIG. 3. In this manner, there is formed first leg 40 and second leg 42 extending in transverse direction 22. Legs 40 and 42 in combination with slot 36 provide a tolerance opening within which automatic closing device 16 may be inserted without contacting or otherwise disrupting attachment of planar member 30 to door 12.
Planar member 30 may be formed of a wood composition. Additionally, indicia or other designs may be incorporated on inner surface 34 to provide a pleasing design. In the alternative, planar member 30 may be formed of a plastic material of differing colors having indicia formed thereon or may be provided in a transparent material such that the inner surface of storm or screen door 12 may be visible therethrough. Additionally, planar member 30 may be formed of a metal composition such as aluminum or some like material.
As can be seen from FIGS. 1, 2 and 3, hinge members 46 are secured to an inner surface at door 12 and to an outer surface 44 of planar member 30. In general, hinge members 46 are L-shaped in contour and secured to planar member 30 through screws, bolts or other like fastening mechanisms 48. Hinge members 46 are rotationally displaceable about axis line 50 extending in vertical direction 32. In this manner, it is seen that planar member 30 is rotationally displaceable about a vertically directed axis line. Each of hinge members 46 are mounted respectively to first leg 40 and second leg 42 of planar member 30 near or on first end 38. In installation, it must be remembered that hinge members 48 are to be vertically alignable each with respect to the other in order that the entire planar member 30 be rotational in a horizontal plane about axis pivot lines 50 of each of hinge members 46.
Door system 10 further includes actuating means 52 for interfacing with latch lever 28 to displace such. Actuating mechanism 52 is fixedly secured to planar member 30 and releasably captures latch lever 28. Latch lever 28 is positionally located to permit contact relation with actuating mechanism 52. Actuating mechanism or latch receiving frame member 52 includes opening 54 within which latch lever 28 is received in transverse direction 22. As can be seen, latch receiving frame member 52 includes opposingly displaced side walls 56 and 58 which act as guideways for insert of latch lever 28. Frame member 52 includes base element 60 having bolts, screws or other fastening systems 62 passing through outer surface 44 of planar member 30 in order to positionally locate in secured fashion actuating mechanism 52 to planar member 30.
Door opening system further includes recess section 64 extending in vertical direction 32 formed within second end 66 of planar member 30. Recess 64 is formed for the purpose of providing an opening within which a door knob may be inserted without interfering with planar member 30. Thus, when door 14 is placed in a closed position, a door knob associated therewith will not contact planar member 30 to inadvertently open outer or screen door 12.
In general practice, latch lever 28 is located vertically above or below the door knob of inner door 14. The vertical displacement of door latch lever 28 and the inner door knob is of consequence such being to avoid interference between latch lever 28 and the door knob when doors 14 and 12 are in a mutually closed position. Cut out or recess section 64 provides sufficient clearance for inner door knob to pass therethrough without contacting planar member 30.
Although this invention has been described in connection with specific forms and embodiments thereof, it will be appreciated that various modifications other than those discussed above may be resorted to without departing from the spirit or the scope of the invention. For example, equivalent elemental structures may be substituted for those specifically shown and described, certain features may be used independently of other features, and in some cases, elements may be reversed, all without departing from the spirit or the scope of the invention as defined in the appended claims.
|
A door opening system for permitting ingress and egress through a door utilizing a displaceable impact loading in one motion of a user. The door opening system includes a broad surface planar member which extends in a transverse direction across the door to be opened. The planar member has a mechanism for actuating a door latch mounted to a rear surface thereof. By displacing the planar member in a unitary direction, the actuating mechanism which interfaces with a latch lever displaces the latch lever and removes the lever from a catch member. Thus, the door is unlatched and continued motion or displacement by the body of the user against the planar member causes an opening of the door.
| 4
|
BACKGROUND OF THE INVENTION
[0001] The invention relates to a pen/pencil/marker holder in combination with a bookmark/placesaver, which optionally includes a magnifying lens.
[0002] Readers often wish to underline or mark passages or to jot notes in margins. They would value the convenience of having a device to store a pen or highlighter with books they are reading.
[0003] A reader would also find a bookmark useful for marking the page he has finished reading. Even more useful would be a bookmark which acts as a placesaver, indicating the very passage which one has completed.
[0004] A device which combines these functions would be especially useful. Combination pen holders/bookmarks have been disclosed in the prior art, for example, Fred P. Gonot, Jr. et al., U.S. Pat. No. 4,162,800; Kip H. Dopps, U.S. Pat. No. 4,706,995; John R. Knight, U.S. Pat. No. 5,095,846; Linda S. Leake, U.S. Pat. No. 5,501,171; and Douglas E. Rigvey, U.S. Pat. No. 5,881,434. However, none of these are especially easy to use, and several could damage the spines or pages of the books with which they are used. In particular, U.S. Pat. No. 4,162,800 discloses a bookmark/holder which functions like a giant rubber band, having slits or openings for a pen. The elastic portion could damage pages, and the pen, which is poorly secured, could easily be lost. None of them disclose a placesaver.
SUMMARY OF THE INVENTION
[0005] The present invention has a strip of material, with an optional elastic segment, the ends of which are wrapped around the cover of a book and fastened together with complementary Velcro™ strips. An optional telescoping strip with Velcro™ allows the present invention to be used on large books. A pocket for holding one or more pens or markers is mounted on the front section of the strip. A ribbon of material is attached to the front section of the strip. The ribbon is used as a bookmark. Threaded onto the ribbon is a placesaver arrow, which can be used to indicate the passage of the book which the reader last read. An optional magnifier can be mounted onto the arrow.
[0006] It is an object of the present invention to provide a utilitarian, yet attractive, combination pen holder and bookmark/placesaver, which gives a reader easy access to and storage of writing instruments, as well as a device for relocating the page of the book, as well as the last passage, that he has read.
[0007] It is yet another object of the invention to provide a combination pen holder and bookmark/placesaver which is easy to install and is easy to use.
[0008] A further object of the invention is to provide a combination pen holder and bookmark/placesaver which is adjustable, depending on the size of the book.
[0009] Other objects of the invention will become obvious when the embodiment is more fully described in the specifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a perspective view showing the combination pen holder and bookmark/placesaver of the present invention.
[0011] [0011]FIG. 2 is a perspective view of an open book, showing the bookmark/placesaver portion in use.
[0012] [0012]FIG. 3 is a perspective view showing the combination penholder and bookmark/placesaver of the present invention, showing the elastic portion and also the Velcro™ strips and circles.
[0013] FIGS. 4 A- 4 B are details showing the optional adjustable telescoping Velcro™ strip.
[0014] [0014]FIG. 5 is a detail showing the optional magnifier attached to the placesaver arrow.
[0015] FIGS. 6 A- 6 D show the method of using the combination pen holder and bookmark/placesaver of the present invention. In FIG. 6A, the open strip of material has been laid on the inside of a book cover, and the bookmark/placesaver has been inserted to point to a passage in the book. In FIG. 6B, the bookmark ribbon has been pulled down and the book has been closed. In FIG. 6C, the lower portion of the invention has been folded over the front cover of the book. In FIG. 6D, the upper portion of the device has been pulled over and affixed to the lower portion. Two pens have been inserted into the holding pocket, and the flap is ready to be closed.
DESCRIPTION OF PREFERRED EMBODIMENT
[0016] Referring to the drawings, the combination pen holder and bookmark/placesaver of the present invention is referred to generally as the device 1 . The device 1 has been wrapped around the cover 2 of a book 3 , and the book 3 has been closed. Two writing instruments 4 a , 4 b , which can be pens, pencils, markers, highlighters, or other such implements, have been stored in the pocket 5 of the device 1 . A flap 6 which can be closed over the writing instruments 4 a , 4 b has been attached to top strap 7 , by sewing or other means. Velcro™ circles 8 a , 8 b can be used to keep the flap 6 closed. The pocket 5 is fastened to the bottom strap 9 with Velcro™ strips 10 a (not shown), 10 b . A ribbon 11 , which functions as a bookmark, is attached to the top strap 7 , by sewing or other means. The device 1 is shown and described in more detail infra.
[0017] The bookmark ribbon 11 and the placesaver arrow 12 are shown in FIG. 2. The ribbon 11 has been inserted through openings 13 a , 13 b in the extension 14 of the placesaver arrow 12 . The pointer 15 , the end of the placesaver arrow 12 , is placed next to the portion of the text 16 which the reader wishes to “mark” (i.e., he has just finished the passage or he will return to the passage when he resumes reading). The stiff insert 17 has been pushed into the crease 18 between the pages of the book 3 to keep the placesaver arrow 12 from moving around. The end of the ribbon 11 can be pulled down to dangle past the bottom edge of the book 3 ; the ribbon will move freely through the openings 13 a , 13 b of the placesaver arrow 12 .
[0018] As shown in FIG. 3, the device 1 is assembled in a unitary fashion. The pocket 5 , the flap 6 , the top strap 7 , and the bottom strap 9 are generally made from a fabric material, which can be selected from patterned fabrics for added attractiveness. These pieces can also be made from sturdier materials, such as leather or plastic.
[0019] A piece of flat elastic 19 connects the top strap 7 and the bottom strap 9 , allowing the reader to slightly stretch the elastic strip 19 and thereby snugly attach the device I to a book cover when mating the Velcro™ strips 10 a , 10 b . A second partitioned pocket 20 a , 20 b can be created by adding additional material and sewing a divider seam 21 . The partitioned pocket 20 a , 20 b can hold two pens, while the main pocket 5 holds one large writing instrument or other implement.
[0020] The ribbon 11 shown is typically made from fabric material. The placesaver arrow 12 is generally made of the same material as the pocket 5 , the flap 6 , the top strap 7 , the bottom strap 9 , such as fabric, leather or plastic. The stiff insert 17 is made of plastic. The extension 14 and the arrow 12 may be reinforced with additional material or plastic.
[0021] FIGS. 4 A- 4 B show an optional feature to make the device 1 adjustable for use with a larger book. A telescoping strip 22 covered with an additional Velcro™ strip 10 c can be inserted into a slit 23 formed at the free end of bottom strap 9 . The telescoping strip 22 can be slid out to add length to the Velcro™ strip 10 b on the bottom flap 9 , thereby allowing improved mating with the Velcro™ strip 10 a on top strap 7 , particularly when the reader is using the device 1 with a large book.
[0022] [0022]FIG. 5 shows a optional magnifier, which can be used to enhance the usefulness of the placesaver arrow 12 . A side of a rectangular magnifier 24 , made from plastic or glass, can be attached to the extension 14 of the placesaver arrow 12 , ordinarily by sewing or gluing. A protective flap 25 , comprising a long rectangular piece of material, is also attached to the extension 14 , under the magnifier 24 . The Velcro™ closure 26 a on the end of the protective flap 25 mates with a Velcro™ closure 26 b on the extension 14 , allowing the reader to fold the protective flap 25 over the magnifier 24 , to prevent scratching its surface. The reader can pull back the protective flap 25 and use the magnifier 24 to read small type.
[0023] As shown in FIG. 6A, the reader has laid the length of the device 1 over the inside of a book cover 2 . He has used the bookmark ribbon 11 to mark a page and has used the placesaver arrow 12 to mark a place in the text 16 .
[0024] In FIG. 6B, the book 3 has been closed. The bookmark ribbon 11 marks the page.
[0025] In FIG. 6C, the bottom strap 9 has been folded over the front of the book cover 2 .
[0026] In FIG. 6D, the top strap 7 , with the pocket 5 , has been folded over the bottom strap 9 , pulled tight, and secured thereto with Velcro™ strips 10 a (not shown), 10 b . Pens 4 a , 4 b have been inserted into the pocket 5 .
|
A bookmark/placesaver in combination with a holder for writing implements is disclosed. The holder portion includes a strip of material with complementary mating elements. The strip of material is wrapped around the front cover of a book and the mating elements are attached. An optional lengthening element allows the device to be used on large books. A bookmark with a placesaver allows the reader to mark a page and passage of a book. An optional magnifier can be included on the placesaver.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of International Application No. PCT/US2008/008027, filed 26 Jun. 2008, which claims the benefit of U.S. Provisional Application No. 60/966,022, filed 24 Aug. 2007.
TECHNICAL FIELD
Embodiments of the invention relate generally to the liquefaction of gases, and more specifically liquefaction of natural gas, particularly the liquefaction of gases in remote locations.
BACKGROUND
Because of its clean burning qualities and convenience, natural gas has become widely used in recent years. Many sources of natural gas are located in remote areas, great distances from any commercial markets for the gas. Sometimes a pipeline is available for transporting produced natural gas to a commercial market. When pipeline transportation is not feasible, produced natural gas is often processed into liquefied natural gas (which is called “LNG”) for transport to market.
In the design of an LNG plant, one of the most important considerations is the process for converting the natural gas feed stream into LNG. Currently, the most common liquefaction processes use some form of refrigeration system. Although many refrigeration cycles have been used to liquefy natural gas, the three types most commonly used in LNG plants today are: (1) the “cascade cycle,” which uses multiple single component refrigerants in heat exchangers arranged progressively to reduce the temperature of the gas to a liquefaction temperature; (2) the “multi-component refrigeration cycle,” which uses a multi-component refrigerant in specially designed exchangers; and (3) the “expander cycle,” which expands gas from feed gas pressure to a low pressure with a corresponding reduction in temperature. Most natural gas liquefaction cycles use variations or combinations of these three basic types.
The refrigerants used may be a mixture of components such as methane, ethane, propane, butane, and nitrogen in multi-component refrigeration cycles. The refrigerants may also be pure substances such as propane, ethylene, or nitrogen in “cascade cycles.” Substantial volumes of these refrigerants with close control of composition are required. Further, such refrigerants may have to be imported and stored imposing logistics requirements. Alternatively, some of the components of the refrigerant may be prepared, typically by a distillation process integrated with the liquefaction process.
The use of gas expanders to provide the feed gas cooling thereby eliminating or reducing the logistical problems of refrigerant handling has been of interest to process engineers. The expander system operates on the principle that the feed gas can be allowed to expand through an expansion turbine, thereby performing work and reducing the temperature of the gas. The low temperature gas is then heat exchanged with the feed gas to provide the refrigeration needed. Supplemental cooling is typically needed to fully liquefy the feed gas and this may be provided by additional refrigerant systems, such as secondary cooling loops. The power obtained from cooling expansions in gas expanders can be used to supply part of the main compression power used in the refrigeration cycle. Though a typical expander cycle for making LNG can operate at the feed gas pressure, typically under about 5,516 kPa (800 psia), a high pressure primary cooling loop had been found to be particularly promising. See, for example, WO 2007/021351. It has also been discovered that adding external cooling to such a primary cooling loop provides additional advantages in many situations. See PCT/US08/02861.
Because expander cycles result in a high recycle gas stream flow rate and resulting high cooling load, introducing inefficiencies for the primary cooling (warm) stage, gas expander processes such as described above further cool the feed gas after it has been pre-cooled using a refrigerant in a secondary cooling unit. For example, U.S. Pat. No. 6,412,302 and U.S. Pat. No. 5,916,260 present expander cycles which describe the use of nitrogen as refrigerant in the sub-cooling loop. The primary (warm-end) expander cooling loop operates at low pressure and therefore limits the fraction of the feed gas cooling load provided by this primary loop. Consequently, a nitrogen (or nitrogen-rich) refrigerant is required in the sub-cooling loop. WO 2007/021351 (above) uses a portion of the flash gas derived from the feed gas in the final separation unit. Thus, generally, an element in expander cycle processes is the requirement for at least one second refrigeration cycle to sub-cool the feed gas before it enters the final expander for conversion of much, if not all, remaining gaseous feed to LNG.
Though this process performs comparably to alternative mixed external refrigerant LNG Production processes, including mixed expander-refrigerant processes, it has been of interest to improve the efficiency of the process of expander cycles for making LNG. In particular it has been of interest to use less fuel and reduce the power generation equipment required, especially for hard to reach locations, such as offshore or in environmentally severe onshore locations.
Other potentially relevant information may be found in International Publication No. WO2007/021351; Foglietta, J. H., et al., “Consider Dual Independent Expander Refrigeration for LNG Production New Methodology May Enable Reducing Cost to Produce Stranded Gas,” Hydrocarbon Processing, Gulf Publishing Co., vol. 83, no. 1, pp. 39-44 (January 2004); U.S. App. No. US2003/089125; U.S. Pat. No. 6,412,302; U.S. Pat. No. 3,162,519; U.S. Pat. No. 3,323,315; and German Pat. No. DE19517116.
SUMMARY OF THE INVENTION
The invention is a process for liquefying a gas stream, particularly one rich in methane, said process comprising: (a) providing said gas stream at a pressure of from 600 to 1,000 psia as a feed gas stream; (b) providing a refrigerant at a pressure of less than 1,000 psia; (c) compressing said refrigerant to a pressure greater than or equal to 1,500-5,000 psia to provide a compressed refrigerant; (d) cooling said compressed refrigerant by indirect heat exchange with a cooling fluid; (e) expanding the refrigerant of (d) to cool said refrigerant, thereby producing an expanded, cooled refrigerant at a pressure of from greater than or equal to 200 psia to less than or equal to 1,000 psia; (f) passing said expanded, cooled refrigerant to a first heat exchange area; (g) compressing the gas stream of (a) to a pressure of from greater than or equal to 1,000 psia to less than or equal to 4,500 psia; (h) cooling said compressed gas stream by indirect heat exchange with an external cooling fluid; and, (i) passing said compressed gas stream through the first heat exchange area to cool at least a part thereof by indirect heat exchange, thereby forming a compressed, further cooled gas stream.
In a preferred embodiment, the feed gas stream in (g) is compressed to 1,500 to 4,000 psia (10342 to 27579 kPa), more preferably 2,500 to 3,500 psia (17237 to 24132 kPa), for optimization of overall power requirements for the gas, methane-rich gas, or natural gas, liquefaction.
In another embodiment of the present invention a system for treating a gaseous feed stream is provided. The system includes: a gaseous feed stream; a first refrigeration loop having a refrigerant stream, a first compression unit, and a first cooler configured to produce a compressed, cooled refrigerant stream; a second compression unit configured to compress the gaseous feed stream to greater than 1,000 psia (8,274 kPa) to form a compressed gaseous feed stream; a second cooler configured to cool the compressed gaseous feed stream to form a compressed, cooled gaseous feed stream, wherein the second cooler utilizes an external cooling fluid; and a first heat exchange area configured to further cool the compressed, cooled gaseous feed stream at least partially by indirect heat exchange with the compressed, cooled refrigerant stream to produce a sub-cooled, compressed, cooled gaseous feed stream.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of one embodiment for producing LNG in accordance with the process of this invention where the feed gas stream 10 is compressed in accordance with the invention prior to being cooled by the primary cooling loop 5 which optionally may use a portion of the feed gas 11 , before the compression, as the primary cooling loop 5 refrigerant, and a portion of the expanded, cooled feed gas 10 d is used as a refrigerant in a secondary cooling loop 6 .
FIG. 2 is a preferred embodiment where the secondary cooling loop 6 is a closed loop using nitrogen gas, or a nitrogen-rich gas, or a portion of the flash gas 17 from a gas-liquid separation unit 80 .
FIG. 3 represents the respective cooling curves for heat exchanger 50 at conventional low feed gas pressure ( FIG. 3A ) and the invention process elevated feed gas pressure ( FIG. 3B ).
DETAILED DESCRIPTION
Embodiments of the present invention provide increased efficiencies by taking advantage of elevating the pressure of the feed gas stream for subsequent heat exchange cooling in both a primary cooling loop and one or more secondary cooling loops. Additional benefit or improvement of the elevated pressure results when a portion of the cooled, elevated feed pressure stream is extracted and used as the refrigerant in a sub-cooling loop. In the prior art, the feed gas is provided typically at a pressure less than about 800 psia (5516 kPa). To enhance cooling the feed gas may be combined with one or more cooling streams of the secondary cooling loops, particularly where such cooling stream, or streams, consists of recycled feed gas or fractions or portions thereof. However, in doing so, the feed stream and provided cooling stream must typically be at the same pressure so as to allow piping, joints and flanges to be economically sized and constructed with characteristics suitable to the larger volume feed gas stream and to minimize the number of streams passing through each heat exchange area. Operating the primary heat exchange at this low pressure limits the thermodynamic performance since an ideal matching of the cooling curve of the feed gas to the warming curve of the primary refrigerant cannot be achieved. Further, since the pressure of the primary refrigerant stream is fixed by the primary heat exchanger cold end temperature, the refrigerant stream condition cannot be changed to better match the cooling curve of the feed stream.
The improved embodiments of the present invention involve operating the feed gas and/or the secondary cooling stream at elevated pressures and employing heat exchangers capable of high-pressure operation (e.g., printed circuit heat exchangers manufactured by the Heatric Company, now part of Meggitt Ltd. (UK)). Operation at the elevated pressures allows reduction of the refrigeration load, or cooling requirement, in the primary heat exchange unit and allows a better match of the composite cooling curves in it. As shown below in data Table 1 the cooling load for the feed gas stream 10 b from the inlet to exchanger 50 to the exchanger 55 outlet at 10 d is reduced by 16% as the pressure is increased from 1,000 psia (6895 kPa) to 3,000 psia (20,684 kPa). As noted, operating at high pressure allows a shift of the cooling load from the high pressure primary cooling loop 5 to the ambient cooling units 35 and 37 that require no compression. Further, as shown in FIGS. 3A and 3B , the cooling curves are better matched at the higher pressure 3000 psia (20684 kPa) in FIG. 3B and pinched at the lower pressure of 800 psia (5516 kPa) in FIG. 3A for cooling the feed gas stream 10 b in exchanger 50 to provide cooled stream 10 c . This results in significant improvement in the overall performance of the process of WO 2007/021351.
FIG. 1 illustrates one embodiment of the present invention in which a high pressure primary expander loop 5 (i.e., an expander cycle) and a sub-cooling loop 6 are used. In this specification and the appended claims, the terms “loop” and “cycle” are used interchangeably. In FIG. 1 , feed gas stream 10 enters the liquefaction process at a pressure less than about 1,200 psia (8274 kPa), or less than about 1,100 psia (7584 kPa), or less than about 1,000 psia (6895 kPa), or less than about 900 psia (6205 kPa), or less than about 800 psia (5516 kPa), or less than about 700 psia (4826 kPa), or less than about 600 psia (4137 kPa). Typically, the pressure of feed gas stream 10 will be about 800 psia (5516 kPa). Feed gas stream 10 generally comprises natural gas that has been treated to remove contaminants using processes and equipment that are well known in the art. Optionally, after being passed through an external refrigerant cooling unit 35 , typically at ambient cooling temperature, a portion of feed gas stream 10 is withdrawn to form side stream 11 , thus providing, as will be apparent from the following discussion, a refrigerant at a pressure corresponding to the pressure of feed gas stream 10 , namely any of the above pressures, including a pressure of less than about 1,200 psia (8274 kPa).
The refrigerant for the primary expander loop 5 may be any suitable gas component, preferably one available at the processing facility, and most preferably, as shown, is a portion of the methane-rich feed gas stream 10 . Thus, in the embodiment shown in FIG. 1 , a portion of the feed gas stream 10 is used as the refrigerant for expander loop 5 . The embodiment shown in FIG. 1 utilizes a side stream that is withdrawn from feed gas stream 10 before feed gas stream 10 is passed to a compressor, the side stream 11 of feed gas to be used as the refrigerant in expander loop 5 may be withdrawn from the feed gas stream 10 before the feed gas stream 10 a has been passed to the initial cooling unit 35 . Thus, in one or more embodiments, the present method is any of the other embodiments herein described, wherein the portion of the feed gas stream 11 to be used as the refrigerant is withdrawn prior to the heat exchange area 50 , compressed, cooled and expanded, and passed back to the heat exchange area 50 to provide at least part of the refrigeration duty for that heat exchange area 50 .
Thus side stream 11 is passed to compression unit 20 where it is compressed to a pressure greater than or equal to about 1,500 psia (10,342 kPa), thus providing a compressed refrigerant stream 12 . Alternatively, side stream 11 is compressed to a pressure greater than or equal to about 1,600 psia (11,032 kPa), or greater than or equal to about 1,700 psia (11,721 kPa), or greater than or equal to about 1,800 psia (12,411 kPa), or greater than or equal to about 1,900 psia (13,100 kPa), or greater than or equal to about 2,000 psia (13,789 kPa), or greater than or equal to about 2,500 psia (17,237 kPa), or greater than or equal to about 3,000 psia (20,684 kPa), thus providing compressed refrigerant stream 12 . As used in this specification, including the appended claims, the term “compression unit” means any one type or combination of similar or different types of compression equipment, and may include auxiliary equipment, known in the art for compressing a substance or mixture of substances. A “compression unit” may utilize one or more compression stages. Illustrative compressors may include, but are not limited to, positive displacement types, such as reciprocating and rotary compressors for example, and dynamic types, such as centrifugal and axial flow compressors, for example.
After exiting compression unit 20 , compressed refrigerant stream 12 is passed to cooler 30 where it is cooled by indirect heat exchange with ambient air or water to provide a compressed, cooled refrigerant 12 a . The temperature of the compressed refrigerant stream 12 a as it emerges from cooler 30 depends on the ambient conditions and the cooling medium used and is typically from about 35° F. (1.7° C.) to about 105° F. (40.6° C.). Where the ambient temperature is in excess of 50° F. (10° C.), more preferably in excess of 60° F. (15.6° C.), or most preferably in excess of 70° F. (21.1° C.), the stream 12 a is optionally passed through a supplemental cooling unit (not shown), operating with external coolant fluids, such that the compressed refrigerant stream 12 a exits said cooling unit at a temperature that is cooler than the ambient temperature. The external refrigerant cooled compressed refrigerant stream 12 a is then expanded in a turbine expander 40 before being passed to heat exchange area 50 . Depending on the temperature and pressure of compressed refrigerant stream 12 a , expanded stream 13 may have a pressure from about 100 psia (689 kPa) to about 1,000 psia (6895 kPa) and a temperature from about −100° F. (−73° C.) to about −180° F. (−118° C.). In an illustrative example, stream 13 will have a pressure of about 302 psia (2082 kPa) and a temperature of −162° F. (−108° C.). The power generated by the turbine expander 40 is used to offset the power required to re-compress the refrigerant in loop 5 in compressor units 60 and 20 . The power generated by the turbine expander 40 (and, any of the turbine expanders to be used) may be in the form of electric power where it is coupled to a generator, or mechanical power through a direct mechanical coupling to a compressor unit.
As used in this specification, including the appended claims, the term “heat exchange area” means any one type or combination of similar or different types of equipment known in the art for facilitating heat transfer. Thus, a “heat exchange area” may be contained within a single piece of equipment, or it may comprise areas contained in a plurality of equipment pieces. Conversely, multiple heat exchange areas may be contained in a single piece of equipment.
Upon exiting heat exchange area 50 , expanded refrigerant stream 13 a is fed to compression unit 60 for pressurization to form stream 13 b , which is then joined with side stream 11 . It will be apparent that once expander loop 5 has been filled with feed gas from side stream 11 , only make-up feed gas to replace losses from leaks is required, the majority of the gas entering compressor unit 20 generally being provided by stream 13 b . The portion of feed gas stream 10 that is not withdrawn as side stream 11 is passed to heat exchange area 50 where it is cooled, at least in part, by indirect heat exchange with expanded refrigerant stream 13 and becomes a cooled fluid stream that may comprise liquefied gas, cooled gas, and/or two-phase fluid.
Thus the portion of feed gas stream 10 not withdrawn as side stream 11 is passed to a compressor, such as a turbine compressor 25 , and then subjected to optional cooling with one or more external refrigerant units 37 to remove at least a portion of the heat of compression. There the feed gas stream 10 a is compressed to a pressure greater than or equal to about 1,000 psia (6895 kPa), thus providing a compressed feed gas stream 10 b . Alternatively, side stream 10 a is compressed to a pressure greater than or equal to about 1,500 psia (10342 kPa), or greater than or equal to about 2,000 psia (13789 kPa), or greater than or equal to about 2,500 psia (17237 kPa), thus providing compressed feed gas stream 10 b . The pressure need not exceed 4,500 psia (31026 kPa), as noted earlier, and preferably not exceed 3,500 psia (24132 kPa). Compressed feed gas stream 10 b then enters heat exchange area 50 where cooling is provided by streams from primary cooling loop 5 , secondary cooling loop 6 , optionally, as shown, with flash gas stream 16 .
After exiting heat exchange area 50 , feed gas stream 10 c is optionally passed to heat exchange area 55 for further cooling. The principal function of heat exchange area 55 is to sub-cool the feed gas stream. Thus, in heat exchange area 55 feed gas stream 10 c is preferably sub-cooled by a sub-cooling loop 6 (described hereinafter) to produce sub-cooled fluid stream 10 d . Sub-cooled fluid stream 10 d is then expanded to a lower pressure in expander 45 , thereby cooling further said stream. A portion of fluid stream 10 d is taken off for use as the loop 6 refrigerant stream 14 . The portion of fluid stream 10 d not taken off forms stream 10 e which is optionally passed to an expander 70 to additionally cool sub-cooled fluid stream 10 e to form principally a liquid fraction and a remaining vapor fraction. Expander 70 may be any pressure reducing device, including, but not limited to a valve, control valve, Joule-Thompson valve, Venturi device, liquid expander, hydraulic turbine, and the like. The largely liquefied sub-cooled stream 10 e is passed to a separator, e.g., surge tank 80 where the liquefied portion 15 is withdrawn from the process as LNG having a temperature corresponding to the bubble point pressure. The remaining vapor portion (flash vapor) stream 16 is used as fuel to power the compressor units and may be optionally used as a refrigerant in sub-cooling loop 6 , as illustrated in FIG. 1 . So, prior to being used as fuel, all or a portion of flash vapor stream 16 may optionally be passed from surge tank 80 to heat exchange areas 50 and 55 to supplement the cooling provided in those heat exchange areas. The flash vapor stream 16 may also be used as the refrigerant, or to supplement the refrigerant, in refrigeration loop 5 , not shown.
The refrigerant stream 14 of sub-cooling loop 6 is led through heat exchange area 55 to provide part of the heat removal duty and exits as stream 14 a , which in turn is provided to heat exchange area 50 for further heat removal duty. The thus warmed stream exits as stream 14 b which is compressed in compressor unit 90 , and then cooled in cooling unit 31 , which can be an ambient temperature air or water external refrigerant cooler, or may comprise any other external refrigerant unit(s). This compressed, cooled stream 14 b is then added to feed gas stream 10 a , thus completing loop 6 .
Referring now to FIG. 2 , sub-cooling loop 6 is a closed loop utilizing nitrogen, or nitrogen-containing gas as refrigerant stream 14 . Stream 14 can typically be provided from bottled sources, or from other contiguous air separation and treatment processes, and will be provided typically at a temperature of about 60° F. (15.6° C.) to about 95° F. (35° C.) and a pressure of about 800 psia (5516 kPa) to about 2,500 psia (17237 kPa). Gaseous stream 14 d is provided to expander 41 and exits expander 41 as gaseous stream 14 typically having a temperature from about −220° F. (−140° C.) to about −260° F. (−162° C.) (e.g. about −242° F. (−52° C.)) and a pressure of about 50 psia (345 kPa) to about 550 psia (3792 kPa). Stream 14 can be provided to heat exchange areas 55 and 50 as illustrated. The warmed stream 14 b , after passing through the exchange areas, is then compressed in compression unit 90 and cooled in external refrigerant cooling unit 31 , which can be of the same type as ambient temperature cooler 37 , so as to be approximately at the original temperature and pressure of stream 14 s for merging with or comprising stream 14 c . After cooling, the re-compressed sub-cooling refrigerant stream 14 b becomes stream 14 c , and is passed to heat exchange area 50 where it is further cooled by indirect heat exchange with expanded refrigerant stream 13 , sub-cooling refrigerant stream 14 a , and, optionally, flash vapor stream 16 a before returning to expander 41 as stream 14 d.
Alternatively, in FIG. 2 , a portion of flash vapor 16 is withdrawn through line 17 to fill sub-cooling loop 6 . Thus, a portion of the feed gas from feed gas stream 10 after liquefaction is withdrawn (in the form of flash gas from flash gas stream 16 ) for use as the refrigerant by providing into the secondary expansion cooling loop, e.g., sub-cooling loop 6 . It will again be apparent that once sub-cooling loop 6 is fully charged with flash gas, only make-up gas (i.e., additional flash gas from line 17 ) to replace losses from leaks is required. In sub-cooling loop 6 , stream 14 is drawn through heat exchange areas 55 to become stream 14 a and 50 to become stream 14 b . The sub-cooling refrigerant stream 14 b (the flash vapor stream) is then returned to compression unit 90 where it is re-compressed to a higher pressure and is warmed further. After exiting compression unit 90 , the re-compressed sub-cooling refrigerant stream 14 b is cooled in one or more external refrigerant cooling units (e.g., an ambient temperature cooler 31 , as above). After cooling, the re-compressed sub-cooling refrigerant stream is passed to heat exchange area 50 where it is further cooled by indirect heat exchange with expanded refrigerant stream 13 , sub-cooling refrigerant stream 14 a , and, optionally, flash vapor stream 16 . After exiting heat exchange area 50 , the re-compressed and cooled sub-cooling refrigerant stream is expanded through expander 41 to provide a cooled stream which is then passed through heat exchange area 55 to sub-cool the portion of the feed gas stream to be finally expanded to produce LNG. The expanded sub-cooling refrigerant stream exiting from heat exchange area 55 is again passed through heat exchange area 50 to provide supplemental cooling before being re-compressed. In this manner the cycle in sub-cooling loop 6 is continuously repeated. Thus, in one or more embodiments, the present method is any of the other embodiments disclosed herein further comprising providing cooling using a closed loop (e.g., sub-cooling loop 6 ) charged with flash vapor resulting from the LNG production (e.g., flash vapor 16 ).
EXAMPLES
The below presented tables and description depict performance curves and comparisons developed using an Aspen HYSYS® (version 2006) process simulator, a computer aided design program from Aspen Technology, Inc., of Cambridge Mass. The enthalpy values are calculated using the HYSYS process simulator. The enthalpy values are negative because of the enthalpy reference basis used by HYSYS. In HYSYS, this enthalpy reference basis is the heat of formation at 25° C. and 1 atm (ideal gas).
Table 1 illustrates the cooling load reduction for expander loop 5 and subcooling loop 6 when the cooling loads are compared from operating the feed gas at 1,000 psia (6895 kPa) versus 3,000 psia (20684 kPa), as discussed above.
Tables 2 and 3 below illustrate flow rate, pressures, and power consumption data using the invention process where the feed gas pressure at the entry to the primary heat exchange (e.g., 50 ) was varied from 1,000 psia (6895 kPa) to 5,000 psia (34474 kPa) while keeping the temperature at the cold end of the primary heat exchanger 50 (at 10 c ) constant. The feed gas rate is kept constant and just enough fuel (for the embodiments in FIG. 1 or FIG. 2 ) is separated to provide a fuel source for power production. The feed gas used in this illustrative case is predominantly methane (e.g., about 96%) with about 4% nitrogen. A nitrogen rejection unit (not shown) for the LNG withdrawn from separation unit 80 will be typically in use.
The data of Table 2 and Table 3 illustrate the benefits of the invention on process performance. The flow rate through the primary loop 5 decreases monotonically as the pressure of the feed gas stream 10 b to the heat exchange unit is elevated. This results in a reduction in the primary loop compression horsepower requirement. However, this reduction is partially offset by the increased compression requirement for both the feed gas 10 a and the sub-cooling loop refrigerant in loop 6 , to the elevated pressure. Consequently, the total horsepower (representing the installed compression power) and the net horsepower for the cycle (representing the installed turbine power) do not track the monotonic decrease in the primary loop power requirement. As the pressure of the feed gas increases, the contribution of the feed gas compression to the total compression power requirements becomes increasingly significant, eventually becoming the dominant incremental contributor so as to increase unacceptably the total compression power requirements. On the other hand, at lower feed gas pressures, the composite effect of the increased cooling requirement and the heat exchange inefficiency result in a high compression requirement in primary loop 5 . As a consequence the total power requirement is higher. Accordingly optimum performance has been found unexpectedly to be in the ranges described and claimed in this application.
Further, as shown in Table 2 (below), the refrigerant flow rate through the primary loop 5 is reduced by more than a factor of two as the heat exchange pressure is increased from 1,000 psia (6895 kPa) to 5,000 (34474 kPa) psia. Table 3 shows a similar trend. The reduced flow rate enables the use of compact equipment that is particularly attractive for offshore gas processing applications.
The performance benefits of the invention, as shown by the data in Tables 2 and 3, show that the optimum performance was attained when the primary heat exchanger 50 was operated at a feed gas pressure between 2,000 psia (13789 kPa) and 4,000 psia (27579 kPa). However, there can be variations in the optimal heat exchange unit or feed gas pressure for a given process configuration, based on feed gas composition, feed gas supply pressure prior to compression, refrigerant composition, and the refrigerant pressure in loop 5 , all of which can be determined empirically by those skilled in the art and informed by the description above. For the illustrative example provided, the optimum mode (least total compression power) was determined to be operation at about 2,750 psia (18961 kPa). The primary loop operating pressure for this illustrative example was fixed at 3,000 psia (20684 kPa).
TABLE 1
Cooling Load Reduction Using High Pressure
Total
% Feed
% Feed Load
Stream Condition
Cooling
Load from
from
Enthalpy
Load
Expander
Ambient
Stream
Press.
Temp.
(BTU/lb)/
(BTU/lb)/
Cooling
Cooling
definition
(psia/kPa)
(° F./° C.)
(kJ/kg)
(kJ/kg)
Loops
(Water/Air)
Inlet Feed
1000/6895
95/35
−1879/−4371
321/747
Gas (stream
10)
Exchanger 50
1000/6895
60/15.6
−1901/−4422
299/696
93
7
Inlet (stream
10b) (low
pressure)
Exchanger
3000/20684
60/15.6
−1949/−4536
251/582
78
22
Inlet (stream
10b) (elevated
pressure)
Exchanger 55 Outlet
−240/−151
−2200/−5118
stream 10d
The foregoing application is directed to particular embodiments of the present invention for the purpose of illustrating it. It will be apparent, however, to one skilled in the art, that many modifications and variations to the embodiments described herein are possible. All such obvious modifications and variations are intended to be within the scope of the present invention, as defined in the appended claims.
TABLE 2
Example Case: Natural Gas 1 using feed gas as sub-cooling loop refrigerant (FIG. 1 Configuration)
Primary Loop
Subcool
Primary Loop
Subcool Loop
Feed Gas
Total
Net
Feed
Flow
Loop Flow
Compression
Compression
Compression
Compression
Expander
Compression
Pressure
Mmscfd/
Mmscfd/
Power
Power
Power
Power
Power
Power
Psia/kPa
kg-mole/hr
kg-mole/hr
khp/MW
khp/MW
khp/MW
khp/MW
khp/MW
khp/MW
5000/34474
950/47334
212.1/10564
120.8/90
62.1/46.3
66.8/49.8
267.4/199.4
53.30/39.7
214.1/159.7
4500/31026
977/48669
216.8/10798
124.2/93
61.5/45.9
61.0/45.5
264.4/197.2
53.16/39.6
211.2/157.5
4000/27579
1010/50303
222.5/11082
128.3/96
61.0/45.5
54.8/40.9
261.9/195.3
53.23/39.7
208.7/155.6
3500/24132
1052/52394
229.3/11420
133.8/100
60.5/45.1
48.2/35.9
260.0/193.9
53.73/40.1
206.3/153.8
3000/20684
1103/54934
237.6/11834
140.3/105
59.8/44.6
40.9/30.5
258.7/192.9
54.53/40.7
204.2/152.2
2500/17237
1180/58769
247.9/12347
149.9/112
60.0/44.7
32.9/24.5
260.5/194.3
56.42/42.1
204.1/152.2
2000/13789
1298/64646
261.1/13004
164.2/122
60.1/44.8
23.8/17.8
265.9/198.3
60.01/44.7
205.9/153.5
1500/10342
1550/77197
279.1/13900
193.3/144
59.9/44.7
13.2/9.9
284.1/211.9
69.19/51.6
214.9/160.3
1250/8618
1728/86062
291.0/14493
213.4/159
59.7/44.5
7.0/5.2
297.8/222.1
75.95/56.6
221.9/165.4
1000/6895
2112/105187
306.3/15255
255.1/190
58.7/43.8
0.0/0.0
331.5/247.2
91.34/68.1
240.2/179.1
TABLE 3
Example Case: Natural Gas 2 using nitrogen as sub-cooling loop refrigerant (FIG. 2 Configuration)
Primary Loop
Subcool
Primary Loop
Subcool Loop
Feed Gas
Total
Net
Feed
Flow
Loop Flow
Compression
Compression
Compression
Compression
Expander
Compression
Pressure
Mmscfd/
mmscfd/
Power
Power
Power
Power
Power
Power
psia/kPa
Kg-mole/hr
kg-mole/hr
khp/MW
khp/MW
khp/MW
khp/MW
khp/MW
khp/MW
5000/34474
1417/70573
1061/52843
198/148
93.9/70.0
110.3/82.3
424/316
94.2/70.3
329.8/245.9
4500/31026
1448/72117
1075/53540
203/151
95.4/71.2
100.6/75.0
420/313
94.3/70.3
326.0/243.1
4000/27579
1487/74059
1092/54387
208/155
97.3/72.5
90.4/67.4
418/311
94.8/70.7
322.7/240.6
3500/24132
1534/76400
1112/55383
215/160
99.5/74.2
79.4/59.2
415/310
95.6/71.3
319.6/238.3
3000/20684
1592/79289
1135/56528
223/166
102.2/76.2
67.4/50.3
414/309
97.0/72.3
317.0/236.4
2500/17237
1675/83423
1163/57923
234/175
105.5/78.7
54.1/40.4
416/310
99.5/74.2
316.0/235.6
2000/13789
1799/89598
1199/59716
251/187
109.6/81.7
39.2/29.2
421/314
104.0/77.6
316.9/236.3
1500/10342
2010/100107
1247/62106
277/207
115.4/86.1
21.7/16.2
436/325
112.4/83.8
323.4/241.2
1000/6895
2487/123864
1313/65393
334/249
123.7/92.2
0.0/0.0
479/357
132.8/99.0
346.1/258.1
|
The described invention relates to processes and systems for treating a gas stream, particularly one rich in methane for forming liquefied natural gas (LNG), the process including: (a) providing a gas stream; (b) providing a refrigerant; (c) compressing the refrigerant to provide a compressed refrigerant; (d) cooling the compressed refrigerant by indirect heat exchange with a cooling fluid; (e) expanding the refrigerant of (d) to cool the refrigerant, thereby producing an expanded, cooled refrigerant; (f) passing the expanded, cooled refrigerant to a first heat exchange area; (g) compressing the gas stream of (a) to a pressure of from greater than or equal to 1,000 psia to less than or equal to 4,500 psia; (h) cooling the compressed gas stream by indirect heat exchange with an external cooling fluid; and heat exchanging the compressed gas stream with the expanded, cooled refrigerant stream.
| 5
|
TECHNICAL FIELD
[0001] The invention relates to the purification process for human growth hormone (hGH) in commercial scale by using hydrophobic interactive chromatography, which effectively separates clipped hormone moieties formed during the production of growth hormone by DNA recombinant techniques.
BACKGROUND OF THE INVENTION
[0002] Human Growth Hormone (hGH) is a pituitary derived protein with a number of important biological functions, including protein synthesis, cell proliferation and metabolism. hGH is a 191 amino acid residue polypeptide of approximately 22 kDa. Recombinant human growth hormone (hGH) has been expressed in E.coli both as intracellular as well as secretary protein. A series of chromatographic and/or non-chromatographic methods are then used to obtain the pure protein. It is reported that the region between 140-150 amino acid residues in human growth hormone is sensitive to a number of proteases. This leads to a proteolytically cleaved form of protein whose physical properties are indistinguishable from that of intact molecule. This variant form of hGH can arise during the purification process and its removal poses a major challenge in the production of therapeutic grade growth hormone protein. To enable the use of hGH for therapeutic purpose, it is necessary to remove the clipped molecules.
[0003] Prior art describes techniques, which are different from the present invention in many aspects such as process parameters, equipments used, priority of separation of target moiety, use of number of phases, use of solvents, type of impurity separated. A few prior art documents disclose techniques, which are more useful as analytical techniques rather than as industrial processes of separation.
[0004] U.S. Pat. No. 4,332,717 disclose the use of hydrophobic interaction chromatography for purifying human growth hormone. This patent purifies hGH extracted from the human pituitary glands and is not related to recombinant hGH or its purification. Hence, the impurities arising in this process are different from the one present in the recombinant hormone. Besides use of different media and different columns, the process uses different pressure conditions, different temperature conditions and different binding and elution buffer. The elution gradients are also different. It also describes the use of blue sepharose or agarose in separation and does not teach use of organic and aqueous mixture for elution, which is one of the essential features of the present invention.
[0005] Following references relate to purification of growth hormone obtained by recombinant DNA techniques. In the literature, there are known a few patents like U.S. Pat. No. 4,861,868, which describes the method for producing a recombinant porcine Growth Hormone; U.S. Pat. No. 4,705,848, U.S. Pat. No. 4,694,073, U.S. Pat. No. 4,731,440, U.S. Pat. No. 5,064,943, U.S. Pat. No. 4,975,529, U.S. Pat. No. 5,023,323, U.S. Pat. No. 5,109,117 and U.S. Pat. No. 6,410,694 deal with solubilization and naturation methods as an essential feature, but these are outside the scope of the present invention.
[0006] U.S. Pat. No. 6,022,858 is related to the formulation of hGH wherein the hGH is pre-treated with Zn and optionally with lysine or calcium ions, after which benzyl alcohol is added to it and the pH adjusted to 2-9.
[0007] U.S. Pat. No. 5,734,024 teaches a method for determination of biological activity of recombinant hGH and is good for analytical purposes.
[0008] U.S. Pat. No. 5,182,369 teaches a method where the operations are carried out at a pH less than 6.5 and two-step precipitation is the essential feature. However, process conditions that employ acidic pH may lead to aggregation or acid hydrolysis of proteins and are a disadvantage.
[0009] U.S. Pat. No. 6,451,347 describes a purification method for hGH, wherein complexation with metal ions such as Zn ions is carried out which is not a feature of the present invention. This patent describes the variants arising from the degradation of hGH and not the clipped moieties.
[0010] U.S. Pat. No. 6,451,987 emphasizes the use of cation exchanger for purification of peptides including hGH, but does not mention the separation of the clipped hormone moiety from the intact hGH molecule
[0011] U.S. Pat. No. 6,437,101 teaches a technique wherein aqueous biphasic extraction without the use of chaotropic agents is employed. The process is cumbersome and hence not easy to perform.
[0012] Patents referred in the document by patent numbers are to be construed to have been included by reference so far as the text of the said patents is concerned.
[0013] Even today the real problem in such purification is separation of clipped molecules resulting from mega target molecule. These clipped moieties remain bundled together due to certain other linkages present in the molecule.
[0014] Non-patent prior art documents comprises of following three published papers on use of hydrophobic interaction chromatography for separation of hGH variants, including clipped variant.
[0015] Pavlu and Gellerfors, Bioseparation (1993), 3: 257-265 disclose hydrophobic interaction chromatography of a recombinant human growth hormone, Genotropin.
[0016] Gellerfors et al., Acta Pediatr Scand (Suppl) (1990), 370: 93-100 teaches separation and identification of growth hormone variants by high performance liquid chromatography techniques.
[0017] Wu et al., J. Chromatogr. (1990), 500: 595-606 disclose Application of high-performance hydrophobic interaction chromatography to the characterization of DNA derived human growth hormone.
[0018] The techniques disclosed in all these references make use of a surfactant Brij (Polyoxyethylene 23 lauryl ether) in mobile phase B and peaks corresponding to clipped molecule appear after the main peak These papers disclose use of acetonitrile percentage of 0.5% in mobile phase A and 5% in mobile phase B along with 0.075% Brij. Brij 35 was used to improve recovery of the product from 70% to 99%. Brij 35, being a detergent helps in lowering the interaction of the protein with the matrix thereby and improving recovery. Interestingly, the peak of target molecule precedes the peak of variants. These papers essentially describe HPLC techniques and are better used for analytical purposes rather than for industrial production purposes. The main drawback of these methods is that the use of detergents like Brij is not favoured in industrial scale since its removal from the protein containing solution may be difficult.
[0019] The present invention makes use of organic solvents in much higher proportions and eliminates the use of Brij. Further it is noticed that the peak corresponding to variant precedes the peak of target molecule.
[0020] Prior art mentions resolution between clipped and intact molecules at analytical level loadings of approximately 50-150 μg semi-purified protein per 3.3 ml column volume. In the present invention resolution is achieved at a loading of 1 mg semi-purified protein per ml column volume.
[0021] The limitation of the prior art is the use of a non-ionic surfactant, Brij 35 to enhance the process recovery at an analytical level. This presence of non-ionic surfactant may be undesirable at preparative level, as it is difficult to remove surfactants that remain bound to protein molecules. The claimed process circumvents the need to use surfactant for improving process recovery by using higher amounts of organic solvent in the eluant that can be easily removed by tangential flow filtration or gel filtration chromatography.
OBJECTS OF THE INVENTION
[0022] The main object of the invention is to describe a process for purification of human growth hormone that can effectively separate the clipped molecules from the target molecule.
[0023] Another object of the invention is to provide a process for purification of human growth hormone that effectively removes the clipped molecules first thereby enabling better control over production of target molecule.
[0024] Yet another objective of the present invention is to describe a process for purification of human growth hormone that can be used for multiple purposes such as analytical method for hGH, isolation of the hGH as well as industrial purification of hGH.
[0025] Still another objective of the invention to provide a purification process that can be effectively carried out in the pH range of 8.0 to 9.0.
[0026] Still yet another objective of the present invention is to develop a process for purification of human growth hormone that does not make use of any detergents or surfactants.
SUMMARY OF THE INVENTION
[0027] The invention relates to a novel process for purification of hGH obtained by recombinant technique using hydrophobic interactive chromatography. The invention further relates to the use of polymeric hydrophobic beads as solid support and mixture of aqueous buffers and organic solvents as an eluant to separate target hGH molecule from clipped hormone moieties present as impurities and finally desalting by gel filtration and lyophilizing to obtain purified hGH.
[0028] The features of the present invention will become more apparent from the following description of the inventive concept and the description of the preferred embodiments.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
[0029] The following table describes chromatographic separation conditions for semi-purified hGH with respect to each figure.
[0000]
FIG. #
Chromatography
Buffer A
Buffer B
Sample details
1
Column: Resource
20 mM Sod-
20 mM Sod-
Sample: 1.0 mg
PHE (1.0 ml)
Phosphate/0.4M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
50% Acetonitrile
2
Column: Resource
20 mM Sod-
20 mM Sod-
Sample volume: 1.0 ml
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
40% Acetonitrile
3
Column: Resource
20 mM Sod-
20 mM Sod-
Sample volume: 1.0 ml
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
30% Acetonitrile
4
Column: Resource
20 mM Sod-
20 mM Sod-
Sample 1 mg
PHE (1.0 ml)
Phosphate/0.4M
Phosphate, pH 8.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 8.0
50% Acetonitrile
5
Column: Resource
20 mM Sod-
20 mM Sod-
Sample 1.0 mg
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 7.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 7.0
50% Acetonitrile
6
Column: Resource
20 mM Sod-
20 mM Sod-
Sample 1.0 mg
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 6.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 6.0
50% Acetonitrile
7
Column: Resource
20 mM Sod-
20 mM Sod-
Sample: 1.0 mg
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
50% Methanol
8
Column: Resource
20 mM Sod-
20 mM Sod-
Sample: 1.0 mg
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
40% Methanol
9
Column: Resource
20 mM Sod-
20 mM Sod-
Sample 1.0 mg
PHE (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection 280 nm
Amersham
K 2 HPO 4 , pH 9.0
30% Methanol
10
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 8.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 8.0
50% Methanol
11
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 7.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 7.0
50% Methanol
12
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 6.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 6.0
50% Methanol
13
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
50% isopropanol
14
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
40% isopropanol
15
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
30% isopropanol
16
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 8.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 8.0
50% isopropanol
17
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 7.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 7.0
50% isopropanol
18
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg of ion-
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 6.0/
exchange purified
Amersham
K 2 HPO 4 , pH 6.0
50% isopropanol
sample
Detection: 280 nm
19
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
25% Acetonitrile/
25% methanol
20
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
25% Acetonitrile/
25% isopropanol
21
Column: Resource
20 mM Sodium
20 mM Sodium
Sample: 1 mg
Phenyl (1.0 ml)
Phosphate/0.4 M
Phosphate, pH 9.0/
Detection: 280 nm
Amersham
K 2 HPO 4 , pH 9.0
25% isopropanol/25%
Methanol
22
Column: Resource
20 mM Sod-
20 mM Sod-
Sample: GH, IEX
PHE (1.0 ml)
Phosphate, pH 8.0/
Phosphate, pH 8.0/
fractions, Sample
Amersham
0.4 M K 2 HPO 4
50% Acetonitrile
volume: 1.0 ml,
Detection 280 nm
23
Column: Resource
20 mM Tris/0.4 M
20 mM Tris, pH 9.0/
Sample: 1.0 mg
PHE (1.0 ml)
K 2 HPO 4 , pH 9.0
50% Acetonitrile
Detection 280 nm
Amersham
24
Column: Sephacryl
9 mM sodium
Detection: 280 nm
S-200 HR
phosphate, pH 8.0
(Amersham)100 ml
bed volume
25
Column: Resource
20 mM Sod-
20 M Na—P, pH 8.0
Sample: 1 mg,
PHE (1.0 ml)
Phosphate/0.4 M
Detection 280 nm
Amersham
K 2 HPO 4 , pH 8.0
26
Column: Phenyl
20 mM Sod-
20 M Na—P/50%
Sample: 1 mg,
Sepharose FF (1.0 ml),
Phosphate/0.4 M
acetonitrile, pH 8.0
Detection 280 nm
Amersham
K 2 HPO 4 , pH 8.0
27
Column; Source 15
10 mM NH4Cl/10 mM
20 mM NH 4 Cl, pH
Sample: Cu-IDA
Q, Amersham
Tris, pH 8.0/3%
8.0/7.5% EtOH/
purified hGH having
EtOH
500 mM NaCl
clipped molecule
Detection: 280 nm
Fractions: 1 ml
System used: FPLC at
1 ml/min flow rate
Analyses: 10 μl of
each fraction
analysed on a SDS-
PAGE gel followed
by silver staining
28
Column: Superdex
20 mM Tris, pH 8.0/
Sample: hGH having
75 HR 10/30,
5% Glycerol/150 mM
clipped molecule -
Amersham
NaCl
denatured in 6 M urea
and reduced with 50 mM
DTT for 2 hrs at
RT
Detection: 280 nm
Fractions: 1 ml
System used: FPLC at
0.5 ml/min flow rate
Analyses: 10 μl of
each fraction
analysed on a SDS-
PAGE gel followed
by silver staining
29
Column: HiTrap 1 ml
20 mM Sodium
20 mM Sodium
Sample: hGH having
columns of Phenyl
phosphate, pH 7.0/
phosphate, pH 7.0
clipped molecule
Sepharose FF (high
0.5 m (NH 4 ) 2 SO 4
Detection: 280 nm
sub)/Butyl
Fractions: 1 ml
Sepharose FF/
System used: AKTA
Phenyl Sepharose HP/
Explorer at 1 ml/min
Octyl Sepharose FF
flow rate
DETAILED DESCRIPTION OF THE INVENTION
[0030] In accordance with the object, the present invention discloses a purification technique for hGH. E. coli cells containing recombinant human growth hormone (hGH) gene were grown under standard conditions in a 1 L shake flask. After 8-10 hrs of induction, cells were harvested by centrifuging for 15 min at 4-8° C. The supernatant was discarded and the cell pellet was suspended in Lysis buffer containing 20-50 mM Tris, pH 7.0-9.0 and 100-500 mM NaCl. Cells were disrupted using ultrasonication for 30 min. Temperature during disruption was maintained at 4 to 8° C. by keeping the samples on ice.
[0031] The crude lysate was clarified by centrifugation at 16,000 rpm for 1 hr at 4° C. After centrifugation the pellet was discarded and to the clear supernatant, imidazole was added to give a final concentration of 20 -40 mM. This was loaded onto a 10 ml column of Chelating sepharose beads charged with NiSO 4 . The column was equilibrated at a flow rate of 5-20 ml/min with buffer containing 20 -50 mM Tris pH 7.0-9.0, 100-500 mM NaCl, 20-40 mM Imidazole. Unbound material washed away using the equilibration buffer and after the absorbance at 280 dropped to baseline, elution of bound proteins was carried out using elution buffer containing 20-50 mM Tris pH 7.0-9.0, 100-500 mM NaCl, 200-500 mM Imidazole. Protein concentration in the elution was measured, made to 5-10 mg/ml concentration and kept for enzymatic digestion at 4-10° C. Digestion was carried out for 15-24 hrs and stopped by adding 2 M solution of K 2 HPO 4 , pH 7-9.0 to a give a final concentration of 0.2-0.4M. The digested sample was loaded onto a Phenyl Sepharose FF column (column vol.=15 ml) equilibrated with buffer containing 20-50 mM Tris, 0.2-0.4 M K 2 HPO 4 , pH 7.0-9.0 at a flow rate of 5-10 ml /min−Bound protein eluted with water and the peak fraction collected. This was loaded onto Q Sepharose FF column (column vol=10 ml) equilibrated with 20-50 mM Tris pH 7.0-9.0. The elution was done using a 15-30 column volume linear gradient of 0% A to 30% (v/v) of buffer “A” containing 0.5-2M NaCl. The major peak at 280 nm containing human growth hormone was collected and a solution of 2 M K 2 HPO 4 was added to achieve a final concentration of 0.2-0.6M.
[0032] This sample was analyzed varying pH, equilibrating buffers and eluants conditions using Hydrophobic Interaction Chromatography.
[0033] According to the invention, there is provided a process for the purification of human growth hormone from its clipped moieties of hGH molecule, by using hydrophobic interaction chromatography technique, the said process comprising steps of:
a. loading the sample on the column in presence of high inorganic salt concentration, b. equilibrating the column loaded with sample with an—aqueous buffer, c. eluting the equilibrated column of step(b) with linear gradient of aqueous buffer and organic solvent mixture, d. collecting and combining eluted fractions corresponding to hGH peak, concentrating the combined fractions, e. desalting and lyophilizing the concentrated fractions of step(d) by filtering on Sephacryl S-200 gel equilibrated with disodium hydrogen phosphate solution of pH 6.0-9.0, and f. obtaining purified human growth hormone.
[0040] The process utilizes semi purified human growth hormone as a sample for purification.
[0041] The column used is hydrophobic resin is a cross-linked polystyrene divinyl benzene polymer resin having attached hydrophobic ligand selected from a group consisting of ether, isopropyl, butyl, octyl and phenyl.
[0042] The hydrophobic ligand is preferably phenyl group.
[0043] The inorganic salt is selected from a group consisting of ammonium sulfate, disodium hydrogen phosphate, dipotassium hydrogen phosphate or sodium chloride, preferably disodium hydrogen phosphate and most preferably dipotassium hydrogen phosphate.
[0044] The inorganic salt concentration used is in the range of 0.2-0.6 M, more preferably 0.3-0.4 M.
[0045] The buffer used for equilibrating the column is a mixture of aqueous disodium hydrogen phosphate and dipotassium hydrogen phosphate. The pH of the equilibrating buffer ranges between 6.0 and 9.0, preferably in the range of 8.0 to 9.0.
[0046] The buffer used for eluting protein is a mixture of disodium hydrogen phosphate or tris buffer and an organic solvent.
[0047] The pH of eluting buffer preferably ranging between 8.0 and 9.0
[0048] The organic solvent used for eluting protein is selected from the group consisting of C 1 to C 4 alcohol, acetonitrile and mixtures thereof.
[0049] The organic solvent in the eluting mixture ranges between 40-70% v/v, more preferably 40% -50% v/v.
[0050] The temperature for chromatography separations is preferably in the range of 20-30° C., more preferably 22-24° C.
[0051] The growth hormone peak eluted from the above hydrophobic interaction chromatography step was concentrated and further desalted on a Sephacryl S-200 gel filtration column equilibrated with 2-10 mM disodium hydrogen phosphate of pH 7.0-9.0. Desalted fraction collected and lyophilized to obtain pure hGH.
[0052] It is known that 0.5 to 5% acetonitrile cannot separate the clipped moieties from the recombinant hGH. (Gellerfors P et al. Acta Pediatr Scand (Suppl) (1990) 370, 93-100, Separation and identification of growth hormone variants by high performance liquid chromatography techniques In the present invention, it was found that use of acetonitrile in the range of 50%±10% effectively separates the unwanted clipped molecules first and subsequently the target molecule can be effectively separated with the purity of >99.5%. pH also plays an important role in the efficiency of separation. When the experiments were performed, it was observed that when the pH is acidic there was no effective separation whereas when the pH was increased above neutrality the separation became more and more effective. It was observed that pH range of 8 to 9 yields optimum purification and hence the desirable quality product ( FIG. 1 , FIG. 2 ). After conducting series of experiments it is concluded that pH does play an important role in achieving resolution between the clipped and intact hGH molecules using Resource Phenyl chromatography. Separation is most efficient at pH 8-9. Decreasing the pH below 8.0 reduces resolution ( FIG. 3 ) so much that at pH 6.0 both molecules elute as a single peak. In all the chromatograms the peak on the left corresponds to clipped hGH and on the right is of intact hGH.
[0053] Applicant tried various other techniques to separate clipped molecules from intact hGH were tried as mentioned herein below:
1. Ion-exchange with both polymer as well as sepharose beads—using aqueous buffer as well as mixture of aqueous-organic solvents and detergents 2. Hydrophobic interaction chromatography using sepharose beads of different hydrophobicities 3. Gel filtration chromatography uses native as well as reduced-denatured conditions
[0057] A brief account of the details of conditions used for purification and the outcome features below.
Experimental Details
[0058] Ion-exchange chromatography: Ion exchange chromatography using Source 15 Q beads were tried to separate the intact from clipped hGH molecules using sodium chloride gradient for elution. ( FIG. 27 )
Observation: No separation of Clipped molecules from intact hGH is observed in the above chromatographic process in any of the factions analysed by SDS-PAGE gel. Gel filtration chromatography- Column: Superdex 75 HR 10/30, Amersham Buffer: 20 mM Tris, pH 8.0/5% Glycerol/150 mM NaCl Sample: hGH having clipped molecule—denatured in 6 M urea and reduced with 50 mM DTT for 2 hrs at RT Detection: 280 nm Fractions: 1 ml System used: FPLC at 0.5 ml/min flow rate Analyses: 10 ul of each fraction analysed on a SDS-PAGE gel followed by silver staining ( FIG. 28 ) Observation: No separation of Clipped molecules from intact hGH is observed in the above chromatographic process in any of the factions analysed by SDS-PAGE gel. Hydrophobic interaction Chromatography on Sepharose beads—( FIG. 29 ) Column: HiTrap 1 ml columns of Phenyl Sepharose FF (high sub)/Butyl Sepharose FF/Phenyl Sepharose HP/Octyl Sepharose FF Buffer A: 20 mM Sodium phosphate, pH 7.0/0.5 m (NH 4 ) 2 SO 4 Buffer B: 20 mM Sodium phosphate, pH 7.0 Sample: hGH having clipped molecule Detection: 280 nm Fractions: 1 ml System used: AKTA Explorer at 1 ml/min flow rate Observation: No separation of Clipped molecules from intact hGH is observed in the above chromatographic process The following examples are illustrative of the invention but not to be construed to limit the scope of the present invention. The present invention has been described in terms of its specific embodiments and certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of present invention.
EXAMPLES
Example 1
[0079] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 1 ). Highly pure form of human growth hormone was obtained. (Purity: >99.5%, Yield: 85%)
Example 2
[0080] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/40% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 2 ). Highly pure form of human growth hormone was obtained. (Purity: >99.5%, Yield: 85%)
Example 3
[0081] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/30% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule did not resolve from intact molecule ( FIG. 3 ).
Example 4
[0082] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 8.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 8.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 4 ). Highly pure form of human growth hormone was obtained. (Purity: >99.5%, Yield: 85%)
Example 5
[0083] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 7.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 7.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE ( FIG. 5 ). (Purity: >80%, Yield: 35%)
Example 6
[0084] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 6.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 6.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule did not resolve from intact molecule ( FIG. 6 ).
Example 7
[0085] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/50% Methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 7 ). Highly pure form of human growth hormone was obtained. (Purity: >99.5%, Yield: 85%)
Example 8
[0086] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/40% Methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 8 ). Highly pure form of human growth hormone was obtained. (Purity: >99.5%, Yield: 85%)
Example 9
[0087] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/30% Methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule did not resolve from intact molecule ( FIG. 9 ). (Purity: >95%, Yield: 45%)
Example 10
[0088] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 8.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 8.0/50% methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 10 ). Highly pure form of human growth hormone was obtained. (Purity >98%; Yield 80%)
Example 11
[0089] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 7.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 7.0/50% methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 11 ). (No purity achieved)
Example 12
[0090] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 6.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 6.0/50% methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 12 ). (No purity achieved)
Example 13
[0091] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/50% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 13 ). Highly pure form of human growth hormone was obtained (Purity >99%; Yield 85%).
Example 14
[0092] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/40% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 14 ). Highly pure form of human growth hormone was obtained (Purity >98%; Yield 80%).
Example 15
[0093] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/30% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 15 ) (Purity >95%; Yield 60%).
Example 16
[0094] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 8.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 8.0/50% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 16 ) (Purity not achieved).
Example 17
[0095] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 7.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 7.0/50% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 17 ) (no purity achieved).
Example 18
[0096] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 6.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 6.0/50% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 18 ) (no purity achieved).
Example 19
[0097] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/25% acetonitrile/25% methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 19 ). Highly pure form of human growth hormone was obtained (Purity >99%; Yield 80%).
Example 20
[0098] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/25% acetonitrile/25% isopropanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 20 ). Highly pure form of human growth hormone was obtained (Purity >99%; Yield 85%).
Example 21
[0099] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/25% isopropanol/25% methanol. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 21 ). Highly pure form of human growth hormone was obtained (Purity >99%; Yield 85%).
Example 22
[0100] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a Resource Phenyl column (procured from Amersham Biosciences) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 9.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE according to the method of Laemlli. The gel was run at 25 mA for 45 min and thereafter silver stained to visualize the protein bands ( FIG. 22 ). The clipped hGH molecule eluted ahead of the intact GH molecules and is resolved as seen from the gel picture.
Example 23
[0101] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Tris/0.4 M K 2 HPO 4 , pH 9.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Tris, pH 9.0/50% acetonitrile. Fractions of 1 ml were collected and analysed by SDS-PAGE. The clipped hGH molecule eluted ahead of the intact GH molecules ( FIG. 23 ). Highly pure form of human growth hormone was obtained (Purity: >99.5%, Yield: 85%).
Example 24
[0102] Resource PHE purified protein fraction was loaded to a 100 ml bed volume of Sephacryl S-200 HR column equilibrated with 9 mM disodium hydrogen phosphate buffer, pH 8.0. Column was eluted with the same buffer at 0.4 ml/min. Protein peak, detected at 280 nm was collected and lyophilised. Pure hGH (>99.5%) was obtained with a yield of >95% ( FIG. 24 ).
Example 25
[0103] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Resource Phenyl column (30×6.4 mm) equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 8.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 , pH 8.0. Fractions of 1 ml were collected and analysed by SDS-PAGE. ( FIG. 25 ). No resolution of clipped molecules and intact hGH molecules are obtained.
Example 26
[0104] To the ion-exchange purified fraction of hGH, K 2 HPO 4 is added to a final concentration of 0.4 M. This was injected onto a 1 ml Phenyl Sepharose FF column equilibrated with 20 mM Na 2 HPO 4 /0.4 M K 2 HPO 4 , pH 8.0. Bound proteins were eluted with a 20 ml linear gradient of 20 mM Na 2 HPO 4 /50% acetonitrile, pH 8.0. Fractions of 1 ml were collected and analysed by SDS-PAGE. ( FIG. 26 ). No resolution of clipped molecules and intact hGH molecules are obtained.
|
Adding enough organic solvent to hydrophobic interactive chromatography elution buffer eliminates the need to also add detergent to the buffer when separating poly-peptides. For example, adding about 50% acetonitrile to detergent-free elution buffer enaibls one to separate full-length human growth hormone from its various truncated forms, to obtain hGH with a purity of >99.5%. This technique is useful to purify polypeptide where detergent to contamination in the resulting polypeptide is undesirable.
| 2
|
FIELD OF THE INVENTION
The present invention relates to test sets and more particularly to equipment for testing coin trunk circuits.
BACKGROUND OF THE INVENTION
The typical method of testing a coin trunk circuit is to connect a coin telephone to the trunk circuit, originate various coin and non-coin telephone calls and monitor the central office response to such call originations. However, use of coin telephones for coin trunk testing is cumbersome, inefficient and can result in inaccurate test results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a coin trunk test set is provided for use with both a hand test telephone having first and second terminals, and central office coin circuits including a battery feed source, a reverse battery source, a ringing generator, a coin collect power supply, a coin refund power supply, a coin ground detector and a coin trunk circuit having first and second terminals.
The coin trunk test set includes first sensible indicating means connected between the first terminal of the coin trunk circuit and the first terminal of the hand test telephone. The second terminal of the hand test telephone is connected to the second terminal of the coin trunk circuit.
The first sensible indicating means is operative in response to connection of the battery feed source to the coin trunk circuit to provide a path for battery feed current. The first sensible indicating means is operative in response to the battery feed current to provide a steady first sensible signal of a first characteristic. The first soluble indicating means is further operative in response to connection of the reverse battery source to the coin trunk circuit to provide a path for reverse battery current. The first sensible indicating means is operative in response to the reverse battery current to provide a steady first sensible signal of a second characteristic.
The coin trunk test set further includes second sensible indicating means, connected to the first terminal of the hand test telephone, and first switching means, connected between the second sensible indicating means and ground.
The first switching means is operative to electrically connect the second sensible indicating means to ground. The second sensible indicating means is operative in response to connection of the ringing generator to the coin trunk circuit to provide a path for ringing current. The second sensible indicating means is operative in response to the ringing current to provide a periodic second sensible signal. The first sensible indicating means is also operative to provide a path for the ringing current and it is operative in response to the ringing current to provide periodic first sensible signals of first and second characteristics.
The coin trunk test set further includes second switching means connected between the second terminal of the hand test telephone and ground. The second switching means is operative to electrically connect the second terminal of the hand test telephone and the coin trunk circuit to ground.
The coin trunk test set further includes third sensible indicating means connected between the second terminal of the hand test telephone and the first switching means. The first switching means is further operative to connect the third sensible indicating means to ground. The third sensible indicating means is further operative in response to connection of the coin collector power supply to the coin trunk circuit in a first arrangement to provide a path for coin collect current. The third sensible indicating means is operative in response to the coin collect current to provide a third sensible signal.
The coin trunk test set further includes fourth sensible indicating means connected between the second terminal of the hand test telephone and the first switching means. The first switching measn is further operative to connect the fourth sensible indicating means to ground. The fourth sensible indicating means is further operative in response to connection of the coin return power supply to the coin trunk circuit in a first arrangement to provide a path for the coin return current. The fourth sensible indicating means is operative in response to the coin return current to provide a fourth sensible signal.
The first and second sensible indicating means are operative in response to connection of the coin collect power supply to the coin trunk circuit in a second arrangement to provide a path for coin collect current. The first sensible indicating means is operative in response to the coin collect current to provide the steady first sensible signal of a second characteristic, and the second sensible indicating means is operative in response to the coin collect current to provide a steady second sensible signal. The first and second sensible indicting means are operative in response to connection of the coin return power supply to the coin trunk circuit in a second arrangement to provide a path for coin refund current. The first sensible indicating means is oeprative in response to the coin refund current to provide the steady first sensible signal.
DESCRIPTION OF THE DRAWING
The single FIGURE of the accompanying drawing is a schematic diagram of the coin trunk test set of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawing, the coin trunk test set of the present invention is shown as being connectable between hand test telephone 300 and central office circuits 100.
Central office coin circuits 100 include battery feed coil 110, coin ground detector 120, 50 V DC power supply 130, ringing generator 140, coin collect power supply 150, coin refund power supply 160 and coin trunk circuit 170. This trunk circuit is connected between battery feed coil 110 and tip and ring leads T-co and R-co, respectively. Coin trunk circuit 120 is also connectable to coin ground detector 170, 50 V DC power supply 130, ringing generator 140, coin collect power supply 150 and coin refund power supply 160.
Coin trunk test set 200 includes the parallel combination of light emitting diodes (LED) 210r and 210g connected to resistor 220 which is further connected to ring lead R-ts1. The parallel combination of line LEDS 210r and 210g is further connected to ring lead R-ts2. Coin refund lamp 230 is connected to the cathode of diode 231 and coin collect lamp 240 is connected to the anode of diode 241. The cathode of this diode is connected to the junction of fault and re-ring lamp 250, the anode of diode 231 and coin/non-coin switch contact 260a. Fault and re-ring lamp 250 is further connected to ring lead R-ts2. Lamps 230 and 240 are further connected to each other, to tip lead T-ts2 and the junction of resistors 270 and 280. Resistor 270 is further connected to coin/non-coin switch contacts 260b which are further connected to coin/non-coin switch contacts 260a and sleeve lead SL-1. Resistor 280 is further connected to thermistor 290 which is connected to tip lead T-ts1.
The coin trunk test set is used to test the coin trunk for detection of coin deposit, application of line current, application of coin refund and coin collect voltages, application of coin voltage on both tip and ring leads, application of ringing current and application of 50 V DC touch call disabling voltage.
Battery feed coil 110, ringing generator 140, coin ground detector 120, 50 V DC power supply 130, coin collect power supply 150, coin refund power supply 160, coin circuit 170 and hand test telephone 300 are all old and well known.
In order to use the coin trunk test set, it is connected between hand test telephone 300 and the central office coin circuits 100. Then, the tip, ring and sleeve leads, T-ts1, R-ts1 and SL-1, of the coin trunk test set are connected to the tip, ring and sleeve leads, T-co, R-co and SL-co, respectively, of the central office. Sleeve lead SL-co is further connected to ground. Also, coin test set tip and ring leads, T-ts2 and R-ts2, are connected to hand test telephone 300 and switch 111 is closed to connect battery feed coil 110 to -50 V.
The test person then closes a talk-monitor switch on hand test telephone 300 to initiate testing of the coin trunk. Current then flows from battery feed coil 110, through coin trunk circuit 170, coin trunk test set 200 and hand test telephone 300.
Negative current flows into coin trunk test set 200 via ring lead R-ts1 and then through green line LED 210g. It then passes through hand test telephone 300 and returns to ground via tip lead T-ts1 and T-ts2, resistor 280, thermistor 290, tip lead T-ts1 and T-co, coin trunk circuit 170 and battery feed coil 110. Thus green line LED 210g is lit in reponse to line current flowing through coin trunk 170, coin trunk test set 200 and hand test telephone 300.
Coin/non-coin switch contacts 260a and 260b are initially in the non-coin or open position. Hand test telephone 300 is then used to dial a coin-free call such as 911, 800 WATS or an operator call. Such a call will be completed if the coin trunk circuits are operating properly.
When a coin-required call is initiated, e.g., a seven digit called number, the central office must be provided with an indication that the required base rate coins have been deposited. The central office interprets a resistive ground on tip lead T-co as the indication that the base rate coins have been deposited. Switch contacts 260a and b are closed in order to provide this resistive ground on tip lead T-co.
The central office then closes switch 121 and opens switch 111. When switch 111 opens, battery feed coil 110 is disconnected from the -50 V DC battery feed and green line LED 210g is extinguished. Current then flows from the battery supply connected to coin ground detector 120, through coin ground detector 120, closed switch 121, tip leads T-co and T-ts1, thermistor 290, and resistors 270 and 280. Current then returns to ground via closed contact 260b and sleeve leads SL-1 and SL-co.
The coin-required call is then dialed with hand test telephone 300. If coin ground detector 120 is operating properly, the coin-required call will be processed. Coin ground detector 120 is then disconnected from coin trunk circuit 170.
Upon termination of the coin-required call, the central office applies coin-collect or coin-refund power to the coin trunk test set, depending on whether the call was chargeable or nonchargeable, respectively.
For a chargeable call, coin collect power supply 150 is connected to tip lead T-co via switch 151 and coin trunk circuit 170. This +110 V DC power supply causes positive current to flow to coin trunk test set 200 via coin trunk circuit 170 and the T-co and T-ts1 leads. This current then flows through coin collect lamp 240 via resistor 280 and thermistor 290. This current then returns to ground via diode 241, closed coin contact 260a and sleeve leads SL-1 and SL-co. Coin collect lamp 240 then flows as a result of such current flow, and it thus provides a visual indication of the validity of the coin collect operation.
Similarly, for a nonchargeable call, coin refund power supply 160 is connected to tip lead T-co via switch 161 and coin trunk circuit 170. This -110 V DC power supply causes negative current to flow to coin trunk test set 200 via coin trunk circuit 170 and the T-co and T-ts1 leads. This current then flows through coin refund lamp 230 via resistor 280 and thermistor 290. This current then returns to ground via diode 231, closed coin contact 260a and sleeve leads SL-1 and SL-co. Coin refund lamp 230 then flows as a result of such current flow and it thus provides a visual indication of the validity of the coin refund operation.
If coin collect or coin refund battery were to appear on both the tip and ring leads, a fault condition would exist. Under such conditions, current would flow to coin trunk test set 200 via coin trunk circuit 170 and both tip lead pair T-co/T-ts1 and ring lead pair R-co/R-ts1. If coin refund power supply 160 is so connected to both the tip and ring leads, negative current flows through green line LED 210g via resistor 220 and ring lead R-ts1. This negative current then flows through fault and re-ring lamp 250 and returns to ground via closed coin contact 260a and sleeve leads SL-1 and SL-co. Under such a fault condition, negative current also flows through refund lamp 230 via resistor 280, thermistor 290 and tip lead T-ts1. This negative current then returns to ground via diode 231, closed coin contact 260a and sleeve leads SL-1 and SL-co. Thus the coin refund lamp is lit in addition to the fault and re-ring lamp when coin refund battery appears on both the tip and ring leads.
Similarly, if coin collect power supply 150 is connected to both the tip and ring leads, positive current flows through red line LED 210r via resistor 220 and ring lead R-ts1. This positive current then flows through fault and re-ring lamp 250 and returns to ground via closed coin contact 260a and sleeve leads SL-1 and SL-co. Under this fault condition, positive current also flows through coin collect lamp 240 via resistor 280, thermistor 290 and tip lead T-ts1. This positive current then returns to ground via diode 241, closed coin contact 260a and sleeve leads SL-1 and SL-co. Thus the coin collect lamp is lit in addition to the falt and re-ring lamp when coin collect battery appears on both the tip and ring leads.
When a touch-call telephone is connected to the coin trunk circuit, the central office disables the touch-call pad during the time that an operator is also connected. This disablement is done to prevent fraudulent signaling via the touch-call pad. In order to disable the touch-call pad, the central office disconnects the -50 V DC battery feed from battery feed coil 110 and connects +50 V DC power supply 130 to coin trunk circuit 170 via switch 131. This +50 V DC potential then appears on ring lead R-co. Thus the voltage that normally appears on this lead is reversed in order to disable the touch-call pad and thereby prevent fraudulent signalling.
This voltage reversal is also tested by coin trunk test set 200. The +50 V DC potential on ring lead R-co causes current to flow through red line LED 210r via resistor 220 and ring lead R-ts1. This current then flows through hand test telephone 300 via tip and ring leads T-ts2 and R-ts2, and returns to ground via resistor 280, thermistor 290, tip lead pair T-ts1 and T-co, coin trunk circuit 170 and battery feed coil 110. Thus red line LED 210r glows in response to detection of the touch call pad disabling voltage from +50 V DC power supply 130.
When the central office re-rings a calling coin telephone, it connects ringing generator 140 to coin trunk circuit 170 by operating switch 141. This ringing generator provides a 90 volt, 20 cycle, AC signal which then appears on ring lead pair R-co and R-ts1. Current then alternately flows through red line LED 210r and green line LED 210g via resistor 220. This alternating current then flows through fault and re-ring lamp 250 and returns to ground via closed coin switch contacts 260a and sleeve lead pair SL-1 and SL-co. Thus fault and re-ring lamp 250 and red and green line LEDs, 210r and 210g, flash at the ringing current frequency in response to detection of re-ring current.
Thus the coin trunk test set of the present invention provides an efficient means of testing the central office coin circuits, including the battery feed coil, the coin ground detector, the touch-call pad reverse voltage, the ringing generator, the coin collect and coin refund power supplies and the coin trunk circuit.
It will be obvious to those skilled in the art that numerous modifications of the present invention can be made without departing from the spirit of the invention which shall be limited only by the scope of the claims appended hereto.
|
A test set which tests coin trunk circuits for both normal and abnormal operations. A pair of light-emitting diodes monitor battery feed and reverse current. A first set of switch contacts simulate coin deposit while a second set of switch contacts connect fault, re-ring, coin deposit and coin return monitoring lamps and circuit paths to the coin trunk circuit.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 10/346,833, filed Jan. 17, 2003 ABN which claims the benefit of U.S. Provisional Application 60/353,400, filed Jan. 31, 2002.
FIELD OF THE INVENTION
The present invention relates to a seal assembly for valves and in particular to a gate valve or pendulum valve seal assembly having a replaceable deformable seal ring, said assembly finding particular use in forming a seal between chambers in vacuum equipment employed in the semiconductor industry for chip manufacture.
BACKGROUND OF THE INVENTION
Integrated circuit (IC) chips are typically manufactured in multi-chambered vacuum equipment. Each chamber may contain a different environment, e.g. atmosphere, temperature, and pressure, than adjacent chambers. Chambers are typically isolated from each other by gate valves (or slit valves). Such valves may be utilized for moving semiconductor wafers from one chamber to another. In addition, pendulum valves may be employed to separate chambers from a vacuum source and for the feeding or exhausting of gases. In both gate valves and pendulum valves, sealing is affected by closing a sealing member, also referred to as a disk or door, portion of the valve. Generally, the door comprises a metal plate, sized and shaped for covering the opening within the valve, and a deformable seal, or O-ring, mounted on the sealing surface of the door, near its periphery. The deformable seal is typically made from an elastomeric or thermoplastic polymer.
During use in the manufacture of IC chips, the deformable door seal is exposed to high temperatures and to corrosive plasmas. The latter conditions, coupled with repeated opening and closing of the door, causes the deformable seal ring to deteriorate and, eventually need to be replaced. Deformable seal replacement has been problematic.
Early door designs featured a dovetail-shaped groove running along the periphery of the door sealing surface. The groove was used to hold a deformable O-ring seal or a modified O-ring (U.S. Pat. No. 5,482,297). However, in use, the deformable seal ring could undesirably pop out of the groove when the gate valve door was opened. It could also be difficult and time consuming to install a replacement seal ring within the groove without damaging the seal.
A more recent door design is disclosed in U.S. Pat. No. 6,089,543 wherein the gate valve door comprises a mounting member and a seal plate attached thereto, wherein a deformable seal ring is mounted onto the outer surface of the seal plate. In this design, the deformable seal ring is preferably bonded, by molding in place, onto the seal plate. When it is desired to replace a worn deformable seal ring, the seal plate/deformable seal assembly is readily detached from the mounting member and discarded. A new seal plate/deformable seal assembly is then attached to the mounting member. This design has the economic and environmental disadvantage of not re-using the old seal plate.
U.S. Pat. No. 5,579,718 discloses a slit valve door having a removable O-ring seal that is held in place within a groove that is partially formed by the door and partially formed by a removable wedge insert. However, it may be difficult to install the O-ring seal in this door groove without twisting the O-ring. Twisting can cause premature seal failure.
It is an object of the present invention to provide a valve door having a securely mounted deformable seal element which may be quickly replaced when desired, without the need for replacing a large portion of the door and without damaging the seal element.
SUMMARY OF THE INVENTION
The present invention is directed to a valve seal assembly for use in sealing an opening in a chamber employed in vacuum equipment, particularly in semiconductor manufacturing equipment.
Specifically an aspect of the invention is a valve seal assembly for use in vacuum chambers of semiconductor manufacturing equipment, said valve assembly comprising:
a) a door having a groove for receiving a seal ring, said groove formed on a sealing surface near a periphery of said door, and wherein a first portion of said groove is formed of a base, an outer sidewall and outer lip in said door; b) a securing means for holding a seal ring within said groove on said door, said securing means having an outer sidewall and lip which forms a second portion of said groove; c) fastening means for attaching said securing means to said door; and d) a deformable seal ring shaped and sized to complementarily fit within said groove, said seal ring comprising a first thin portion for complementarily engaging said first portion of said groove and a second thin portion for complementarily engaging said second portion of said groove, and said seal ring having a thick portion located between said first and second thin portions and sized to extend beyond said door lip.
BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is a plan view of an embodiment of the seal assembly of this invention.
FIG. 2 is a cross-section view of an embodiment of the seal assembly of this invention taken along lines 2 — 2 of FIG. 1 .
FIG. 3 is a cross-section view of another embodiment of the seal assembly of this invention taken along lines 2 — 2 of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a plan view of the valve door seal assembly 10 of this invention wherein a deformable seal ring 12 is mounted in a groove near the periphery of the sealing surface of door 14 and held in place by securing means 16 . By “sealing surface” is meant the surface of the door which covers the opening that is sealed when the valve is closed.
FIG. 2 shows, in cross-section along 2 — 2 , the door assembly of this invention. Seal ring 12 is reversibly mounted on the base 18 of a groove on the sealing surface of door 14 . The groove has an outer side wall 20 and an outer lip 22 for complementarily engaging a relatively thin outer portion 30 of deformable seal ring 12 . Securing means 16 has an outer side wall 24 and outer lip 26 for complementarily engaging a relatively thin inner portion 32 of deformable seal ring 12 . Seal ring 12 has a relatively thick portion 34 located between thin portions 30 and 32 . Thick portion 34 is generally parabolic-shaped and it is sized to extend above the lips of both door 14 and securing means 16 for sealing engagement with the surface (i.e. mating flange) surrounding the opening in the valve (not shown). The shape of seal ring 12 results in the requirement for only a relatively minor compressive force in order to form an effective seal under high vacuum. Much more force would be required if seal ring 12 were an O-ring.
Although securing means 16 is shown as a solid disk or wedge in the figures, one skilled in the art would readily recognize that the securing means could equally be a continuous ring, a non-continuous ring, or a series of brackets. Such alternate embodiments are contemplated in this invention. Securing means 16 is reversibly attached to door 14 by fastening means 28 .
Fastening means 28 may include bolts (as shown in FIG. 2 ), screws, pins, adhesives, etc. Such alternative embodiments are included in the present invention. The number and location of fastening means required to adequately attach securing means 16 to door 14 depends upon the shape and size of the securing means and may be readily determined by the skilled practitioner. Optionally, second seal 36 may be used with fastening means 28 ( FIG. 3 ) to form an airtight seal between the fastening means and the door. This ensures that a vacuum leak does not occur due to poor mating between door 14 , seal ring 12 and securing means 16 . Second seal 36 may be a washer, O-ring, square gasket, or the like.
Door 14 and securing means 16 can be fabricated from metals such as stainless steel, aluminum, or other non-deformable metal. The door and securing means may be made of the same material or of different material. Securing means 16 can also be made from polymers having either a modulus or a hardness much greater than that of the material used as the seal ring 12 . Polymers, useful for preparation of the securing means include, but are not limited to nylon, polyether ether ketone (PEEK), polyether sulfone (PES), polytetrafluoroethylene (PTFE), polyimide, or an organic or inorganic composite. Preferably the door and securing means are made of steel or aluminum, most preferably a stainless steel such as 316L, or anodized aluminum.
Seal ring 12 may be fashioned out of elastomer (preferably) or other deformable material such as a thermoplastic resin (e.g. copolymers of tetrafluoroethylene) that is thermally stable and inert to the plasma which is employed in the chip manufacturing equipment. Suitable elastomers include silicone rubber, nitrile rubber, hydrogenated nitrile rubber, EPDM, copolymers of ethylene and an alpha olefin having at least four carbon atoms, and fluoroelastomers, including perfluoroelastomers. For applications requiring seals that may be exposed to high temperatures, harsh chemicals or require very low extractables, a perfluoroelastomer is the preferred elastomer. By “perfluoroelastomer” is meant copolymers comprising copolymerized units of tetrafluoroethylene and copolymerized units of a perfluoro(alkyl vinyl ether) or a perfluoro(alkoxy vinyl ether). Such copolymers may also contain a minor amount (preferably less than 7 mole percent, based on the total number of moles of comonomers) of a cure site such as Br, I, CN, or H. Perfluoroelastomers have been extensively described in the prior art. See, for example, U.S. Pat. Nos. 4,035,565; 4,281,092; 4,529,784; 4,487,903; 5,789,489; 5,936,060; 6,140,437; 6,211,319 B1 and 6,281,296 B1.
Optional second seal 36 may be fashioned out of any of the materials mentioned above as suitable for seal ring 12 . However, since second seal 36 is never exposed to plasmas, it need not be made from expensive perfluoroelastomer or other plasma inert material.
Worn seal ring 12 may easily be replaced in the present invention by the steps of a) disengaging fastening means 28 , b) removing securing means 16 , c) replacing the worn seal ring with a new seal ring, d) repositioning securing means 16 and e) engaging fastening means 28 . The new seal ring easily slides into the groove without twisting.
Finite Element Analysis (FEA) studies of 1) the valve seal assembly of the present invention in the embodiment of a slit valve and 2) the door seal assembly of U.S. Pat. No. 5,579,718 indicate that the door seal of the present invention has a higher contact pressure against the mating flange (while under the same compressive load) than does the U.S. Pat. No. 5,579,718 door seal assembly. This results in better vacuum sealing performance for the seal assembly of the present invention.
The present valve seal assembly finds use in vacuum sealing applications, particularly in gate or slit valves and in pendulum valves utilized in the sealing of vacuum chambers in semiconductor chip manufacturing equipment. Besides the preferred embodiments of the invention illustrated in the drawings and described in detail above, the skilled artisan will readily understand that the invention is capable of alternative embodiments. For example, in order to provide space for thermal expansion of the seal ring, the groove sidewall radius, seal ring width and the undercut geometry of the securing means may be adjusted. Accordingly the invention should not be strictly limited in scope to the preferred embodiments.
|
The present invention is directed to a valve seal assembly for use in multi-chamber vacuum devices. The seal assembly comprises a door and a deformable seal ring running along the periphery of the door, wherein the seal ring is held in place by a reversibly mounted securing means such as a disk, ring or clamp.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to process and apparatus for spreading a chip web from a supply over a width corresponding to the width of the web on a substrate moving below the supply according to a web height distribution specified in the web transversely to the direction of travel of the web.
European Patent No. 0 063 162 describes a process for influencing the density distribution of a chip web to be spread as well as an apparatus for this purpose. From at least one partial flow over a part of its width according to a specified density distribution, a resulting partial amount is removed. By removing a partial amount from a continuous partial flow extending over the width, a desired density distribution is obtained at the site of removal. However, since a further mixing with uninfluenced partial flows takes place, the desired result of a uniform specified density distribution in the laid down web is difficult to obtain.
Also, European Patent No. 0 109 456, describes process and apparatus for equalizing the density distribution in an artifical wood board in which, as a function of the weight distribution measured over a delivery cross section of the bulk material delivered from a supply, a separation command is developed for the amount of bulk weight present in corresponding partial cross sections and deviating from a specified target density distribution for its separation. Such a process is also based on a supply which is delivered over the entire future web width via removal devices so that density fluctuations present in the supply over the entire width also influence the amount to be removed. Even when the amount to be removed is controlled according to the expected profile which is to be produced on the web substrate, it is entirely possible that as a result of inevitable non-uniformities in the supply, a new non-uniformity in the laydown profile of the chips occurs before laydown as a web. The delivery elements for the stored supply extend over the entire width of the future profile and cause unavoidable defects in the state of the art.
Also, by way of background, German Preliminary Published Application No. 2 942 163 describes process and apparatus for dividing a forwarded flow characterized in that the forward flow is continuously delivered to a flow divider and constant partial flows are forwarded along the flow divider while others are constantly forwarded through the flow divider. With such a process and apparatus, the amount of chips delivered to this flow divider are exactly divided but the defects present in the spreading material are also forwarded via a distribution chute.
SUMMARY OF THE INVENTION
The present invention is based on the objective of eliminating defects caused by delivery elements in the transverse distribution of a chip web and of conducting an inspection and control of such transverse distribution. By dividing the spreading material taken from the supply over the entire spreading width and by changes in direction of the individual particles, the defects caused by the removal devices are eliminated. A quasi-uniform orientation takes place of the chip particles coming in unevenly in a cascade so that a correct removal from the uniform chip flow can be initiated via a specified web distribution curve when the web is laid down.
With the arrangements of pairs of rakes which do not interfere with each other, an opening of the non-uniform chip flow is obtained since each particle of the chip flow is deflected at least once in its flow direction and, therefore, is guided towards a uniform mixing with the other particles. Such an apparatus, seen over the width, produces a completely uniform chip web on a substrate. It is assumed in this case that for the same bulk height, the bulk density is also constant when uniform material is used. When a specified bulk height which is comparable to a specified bulk density is to be produced, other measures may be taken.
A pickup device may be provided with a forwarding device. According to the invention, it is possible to return the partial amount present in the pickup device or, to distribute it uniformly over the spreading width. With the arrangement of a weir extending over the entire web width it is possible to uniformly deposit a web layer either underneath the web to be formed or on top of the formed web.
If a web obtained in this way is provided, according to the invention, with additional cover layers, at least one spreading roll is additionally provided below the last cascade. As a result, a slight separation of the chips in the transition zone to the cover layers is obtained. Braking the rate of travel and leveling of the chips is enhanced at the same time.
In a further embodiment of the invention, the pickup device has closable openings which are separated from each other by lands and which may be moved with a cooperating rake towards each other and also transversely to the direction of web travel.
In still another embodiment of the invention, the lands of the pickup device may be constructed as rakes.
A particularly advantageous embodiment includes two rakes provided above each other and above the pickup device. The rakes are movable with respect to each other in a direction transverse to the direction of web travel. As a result of this arrangement, the opening width in the pickup device can be most simply regulated which of necessity leads to a control of the picked up amount.
In order to examine the specified web height, a device is used in which a light beam emitted by a light source strikes the chip web over its width transversely to the forwarding direction. A video camera receives this light beam and forwards the information to a computer in which control information for the pickup device is derived. The light lines recorded over a web length corresponding to a board length are stored over the width of the web in the computer, and subsequently, the board surface is shown on a monitor in a color grid associated with the contours. As a refinement of this concept, especially when a change in the web surface is anticipated, not one but several light beams are emitted over the entire width of the web so that web height changes can be recorded by the same stationary videocamera.
BRIEF DESCRIPTION OF THE DRAWING
Novel features and advantages of the present invention in addition to those noted above will become apparent to those of ordinary skill in the art from a reading of the following detailed description in conjunction with the accompanying drawing wherein similar reference characters refer to similar parts and in which:
FIG. 1 is side elevational view of apparatus for spreading a chip web according to the present invention, with portions thereof in section to show interior details and certain control mechanisms diagramatically shown;
FIG. 2 is an elevational view of a rake distribution device, according to the present invention;
FIG. 3 is a partial side elevational view of the pickup device of FIGS. 1 and 2, according to the present invention; and
FIG. 4 is a front elevational view of the pickup device shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring in more particularlity to the drawing, FIG. 1 shows bulk material 2 being spread in the production of chip boards, waferboard and OSB boards. Bulk material is delivered from a chip supply (not shown) over a rake-like distribution device 1 onto pairs of rakes 5, 6, and 7 located in a housing 4 via distribution chute 3. The pairs of rakes consist of rods each having the same length arranged at a distance from each other and extending over the width of the web of bulk material being dispensed. Preferably, the rods of each rake are fastened at the upper ends thereof to a cross bar 8. The cross bars 8 also extend over the entire width of the housing 4 which is adapted to the width of the web.
The number and the inclination of the rakes shown in FIG. 1 merely represent an exemplified embodiment. Depending on the material to be blended, several cascades one above the other may also be provided. The pair of rakes 5 then forms the first cascade while the pairs of rakes 6 and 7 form the second cascade. According to the invention, the inclination of the pairs of rakes to each other is initiated by rotating the cross bars 8 from outside the housing 4.
In the embodiment of FIG. 1, two spreading rolls 9 are arranged below the last cascade. The function of rolls 9 is to change and brake the uniformly distributed material in its falling direction and/or obtain a slight separation of the chips when a chip board or an OSB board is produced consisting of several layers of chips and the present apparatus is used for the production of the center layer, for example.
In the production of a chip board consisting of several layers, the distribution devices of FIG. 1 may be arranged in series. For example, in the production of three-ply boards, the first and third housings would not include spreading rolls 9 while the second housing would include spreading rolls 9 at its discharge 10.
As shown best in FIG. 1, a pickup device 11 is provided on one rake of the pair of rakes 7 which functions to pick up excess spread material. The function of the pickup device is further explained in connection with FIGS. 2-4. The arrangement of the pickup device of FIG. 1 in front of the rake located the most downstream in the direction of the web forming on a substrate only represents an exemplified embodiment. The pickup device 11 may likewise be located behind the rake which is the most upstream in the direction of web travel, in this case the left rake of the pair of rakes 5.
A web receiving device 12 is shown below the housing 4 extending over the entire spreading width of the bulk material. The web receiving device 12 may be a conveyor belt extending over the width of the chip web or an overlapping flexible or rigid substrate or a combination of such web carriers. The web receiving device 12 moves in the direction of an arrow 13 so that the final web height 14 is obtained at the left end of the housing 4.
A light beam 15 is projected onto the surface of the web over the entire width of the web 16 and produces an image of the web height 14 in a video-camera 17. This image is delivered to a computer 18. When the web height 14 recorded over the width of the web agrees with the specified web height, it is not necessary to forward a control command 19 to an adjusting mechanism 20 (see FIG. 3) in the pickup device 11. A first monitor 21 connected to the computer 18 shows the progression of the web height over the width of a spread web and a second monitor 22 shows the resulting contours in a grid over the length of a finished chip board.
If instead of one light beam 15, according to the invention a number of light beams 15 may be emitted and projected onto the surface of the web by a stationary light source 23. The web surfaces may be recorded with a stationary videocamera 17. The light beams may be substantially different from each other in their height without resulting in diminished spreading accuracy.
Bulk material 2 entering the housing 4 of FIG. 2 extends over the rake-like distribution device 1 and is distributed via the distribution chute 3. The defects of part of the undeflected bulk material 2 remain until the end of the distribution chute. If one partial flow 25 containing these defects strikes the pair of rakes 5, it is divided by the right hand rake of the pair of rakes 5 into another partial flow 26 and the existing partial flow 25. The other partial flow 26 is subdivided again at the left hand rake of the pair of rakes 7. As a result, possible nonuniformities present at the distribution chute 3 are evened out. The partial flow 25 which might still contain distribution defects from the distribution chute 3 will arrive near the pickup device 11 which also extends over the entire width of the deposited web. Since the pickup device cooperates with the right hand part of the pair of rakes 7, in the exemplified embodiment of FIG. 2, the partial flow 25 is also divided at the pickup device. As a result, distribution defects arriving via the distribution chute 3 have now become so small that these defects can be seen as almost having disappeared. But if a greater accuracy is desired, even more cascade stages may be added as a function of the desired accuracy.
Corresponding to the control commands 19, openings 27 of the pickup device are selectively opened according to a double arrow 28 so that the excess amount of bulk material released from the supply (not shown) can flow into the pickup device 11.
As shown in FIG. 2, the pickup device 11 contains a distribution screw 29 which can carry away the incoming material. Instead of returning the released excess bulk material to the supply, a forwarding device 99 transversely movable back and forth may be employed, as shown in more detail in FIG. 3, in order to even out excess material 30 inside the pickup device. If the pickup device 11 in its lower part has an overflow 31 the excess material will then emerge and, depending on the arrangement of the pickup device, will be laid down downstream or upstream near the last cascade as a web base or a web addition.
FIGS. 3 and 4 illustrate the pickup device 11 with the plurality of spaced apart openings 27 and gates 7A that open and close the openings. The operator 20 is responsive to command signals and controls movement 28 of the gate. Lands 40 are formed between the openings 27.
|
Process and apparatus for spreading a chip web from a supply over a width corresponding to the web width on a substrate moving below the supply. Such spreading is accomplished according to a web height distribution specified in the web transversely to the direction of web travel. The apparatus includes a rake-like distribution device and a distribution chute arranged between the supply and the web laydown for the purpose of eliminating defects caused by delivery elements in the transverse distribution of the chip web. An arrangement of several rakes inclined toward one another functions to control the transverse chip distribution.
| 3
|
TECHNICAL FIELD
The subject invention relates to a process for preparing certain 2-alkyl-4-acyl-6-tert-butylphenol compounds, where the acyl substituent has a labile moiety, using a modified Friedel-Crafts reaction.
BACKGROUND OF THE INVENTION
Compounds useful as anti-inflammatory agents which are -alkyl-4-acyl-6-tert-butylphenol compounds, especially 4-acyl-2,6-di-tert-butylphenol compounds, and related derivative thereof, where the 4-acyl substituent has a terminally unsaturated moiety, are disclosed in U.S. Pat. No. 4,708,966 issued to Loomans, Matthews & Miller on Nov. 24, 1987; U.S. Pat. No. 4,847,303 issued to Loomans, Matthews & Miller on Jul. 11, 1989; and U.S. Pat. No. 4,949,428 issued to Dobson, Loomans, Matthews & Miller on Jul. 18, 1989. A process for making such compounds is disclosed in U.S. Pat. No. 4,982,006 issued to Hudec on Jan. 1, 1991.
Friedel-Crafts reactions of aromatic hydrocarbons with acyl halides in the presence of a catalyst such as anhydrous aluminum chloride to produce aromatic compounds having an acyl substituent are well-known. But when the acyl moiety has a labile portion, such as the terminal unsaturation of the compounds of interest herein, side reactions often occur resulting in poor yield and purity of the desired product.
The use of trifluoroacetic anhydride to aid the reaction of an aromatic compound and a carboxylic acid is known; see, e.g., Tedder, J.M., "The Use of Trifluoroacetic Anhydride and Related Compounds in Organic Syntheses", Chemical Reviews. Vol. 55 (1955), pp. 787-827; Galli, C., "Acylation of Arenes and Heteroarenes with in situ Generated Acyl Trifluoroacetates", Synthesis. April, 1979, pp. 303-304; Nishinaga, A., T. Shimizu, Y. Toyoda & T. Matsuura, "Oxygenation of 2,6-Di-tert-butylphenols Bearing an Electron-Withdrawing Group in the 4-Position", Journal of Organic Chemistry, Vol. 47 (1982), pp. 2278-2285. However, when the carboxylic acid reactant has a labile portion, such as a terminally unsaturated moiety, unwanted side reactions can occur, see, e.g., Tedder at page 800. Thus, the ability of such a reaction scheme to prepare 2-alkyl-4-acyl-tert-butylphenol compounds where the 4-acyl substituent has a terminally unsaturated moiety was unknown and unpredictable prior to the invention disclosed herein.
It is an object of the subject invention to provide a process for the preparation of certain 2-alkyl-4-acyl-6-tert-butylphenol compounds, where the acyl substituent has a certain terminally-unsaturated moiety.
It is a further object of the present invention to provide a process for the preparation of such compounds from the corresponding 2-alkyl-6-tert-butylphenol and carboxylic acid reactants with good yield.
It is a still further object of the present invention to provide a process for the preparation of such compounds which provides the compounds at high purity and high yield.
SUMMARY OF THE INVENTION
The subject invention relates to a process for the preparation of 2-alkyl-4-acyl-6-tert-butylphenol compound having the chemical structure: ##STR3## wherein -R is an aliphatic group having a terminally unsaturated moiety selected from --C.tbd.CH and --CH═C═CH 2 , and R' is selected from saturated, straight, branched or cyclic alkyl having from 1 to about 10 carbon atoms; the 2-alkyl-4-acyl-6-tert-butylphenol compound being produced in a reaction mixture comprising the corresponding 2-alkyl-6-tert-butylphenol: ##STR4## the corresponding carboxylic acid: RCOOH, and trifluoroacetic anhydride.
DETAILED DESCRIPTION OF THE INVENTION
The process of the subject invention comprises a modified Friedel-Crafts reaction among a 2-alkyl-6-tert-butylphenol, a carboxylic acid and trifluoroacetic anhydride according to the following reaction scheme: ##STR5##
In the above reaction, -R is -B-Y, wherein -Y is selected from --C.tbd.CH and --CH═C═CH 2 ; and --B--is a saturated, unsubstituted, straight or branched alkylene moiety having from 1 to about 12 carbon atoms. -Y is preferably --C.tbd.CH. -B- is preferably straight chain alkylene having from 1 to about 10 carbon atoms, more preferably from about 2 to about 6 carbon atoms, especially 3 carbon atoms.
In the above reaction, R' is saturated, unsubstituted, straight, branched or cyclic alkyl having from about 1 to about 10 carbon atoms. R' is preferably straight or branched alkyl having from 1 to about 8 carbon atoms; most preferably R' is tert-butyl.
In the above reaction, the carboxylic acid reactant has a pK a of greater than about 3.5, preferably greater than about 4.0.
The above reaction can be carried out in a wide variety of non-polar, liquid solvents which do not react with the above reactants or products, such as hydrocarbons (e.g., hexane, heptane), halogenated hydrocarbons (e.g., dichloroethane), benzene, toluene, acetonitrile, ethers, etc. However, the reactants and reaction products of the subject process are generally miscible as liquids at reasonable temperatures, and no solvent is needed. Therefore, a preferred method for carrying out the above reaction is without the use of a solvent. For large batches, a solvent may be desired to help dissipate the heat of reaction. Heptane and toluene are preferred solvents.
The order of combination of the three reactants is not critical. However, the admixing of trifluoroacetic anhydride with the carboxylic acids of interest is generally highly exo-thermic requiring external cooling. Also, the 2-alkyl-6-tert-butylphenol reactant is often solid at room temperature and must be kept molten during its addition to the trifluoroacetic anhydride/carboxylic acid mixture in order to achieve complete reaction.
A preferred method for carrying out the subject reaction is to dissolve the phenol compound in the carboxylic acid, and to add the trifluoroacetic anhydride slowly. The reaction proceeds spontaneously. When the trifluoroacetic anhydride is added, the resulting reaction is exothermic; external cooling may be used. The trifluoroacetic anhydride is preferably added at a rate such that the temperature of the reaction mixture is controlled as desired.
Another preferred method for carrying out the above reaction is to dissolve the phenol compound in the trifluoroacetic anhydride and to add the carboxylic acid slowly. The reaction proceeds spontaneously. When the carboxylic acid is added, the resulting reaction is exothermic; external cooling may be used. The carboxylic acid is preferably added at a rate such that the temperature of the reaction mixture is controlled as desired.
The temperature of the reaction mixture is preferably controlled at a temperature of from about -20° C. to about 100° C., more preferably from about 0° C. to about 60° C., more preferably still from about 20° C. to about 50° C.; most preferably from about 40° C. to about 45° C. After completion of addition of the third reactant, the reaction mixture is preferably stirred and allowed to cool slowly as the reaction is completed, preferably for less than 24 hours, more preferably for from about one-quarter hour to about 4 hours, more preferably still for from about one-half hour to about 2 hours.
The desired reaction will proceed under a wide range of molar ratios of the three reactants. The preferred molar ratio of the three reactants is about 1.0:1.0:1.0. It is preferred that the molar ratio of trifluoroacetic anhydride to carboxylic acid not be substantially greater than 1.0 because the excess trifluoroacetic anhydride will react with the desired reaction product thus reducing its yield. Excess carboxylic acid causes side reactions to occur; a slight excess helps drive the desired reaction to completion. An excess of the phenol reactant is often difficult to separate from the product during subsequent purification. It is preferable that none of the three reactants be incorporated in the reaction mixture in a molar excess of greater than about 30%, based on the total amount of each of the other two reactants incorporated in the reaction mixture; more preferably none is incorporated in the reaction mixture in a molar excess of greater than about 10%.
Under the above conditions, the quantity of desired product achieved from the subject reaction, based on the quantity of limiting reactant, is generally greater than 70%, typically greater than 85%, often greater than 95%. The product yield ultimately obtained is, of course, highly dependent on the purification steps which follow the above reaction step.
In order to obtain high purity product at high yield, the process of the subject invention preferably includes purification steps following the above reaction step comprising a step of crystallization from methanol/water. Preferably the crystallization from methanol/water follows a step of crystallization from hexane.
A highly preferred purification procedure comprises the following steps: (a) dissolving the above completed reaction mixture in hexane at an elevated temperature, preferably removing water-soluble and acidic impurities by extraction with a basic aqueous solution, and preferably contacting the resulting solution with activated charcoal to reduce color and separating out the charcoal; (b) crystallizing product from the hexane solution at a low temperature, separating and drying the product crystals; (c) dissolving the product crystals in methanol at an elevated temperature, and preferably contacting the methanol solution with activated charcoal to remove color and separating out the charcoal; and (d) crystallizing product from the methanol solution by adding water and lowering the temperature, separating and drying the product crystals.
In step (a) above, the completed reaction mixture is dissolved in hexane, preferably at a temperature of from about 50° C. to about 69° C., more preferably from about 65° C. to about 69° C. The weight ratio of hexane:reaction mixture is preferably from about 20:1 to about 5:1, more preferably from about 10:1 to about 5:1. If the resulting solution is not colorless, color can be removed by the addition of activated charcoal and mixing followed by filtration to remove the charcoal.
Before crystallizing product from the hexane solution in step (b) above, the hexane solution is preferably concentrated by evaporating off a portion of the hexane. Preferably the resulting concentrate has a ratio of hexane to reaction product of from about 10:1 to about 3:1, more preferably from about 8:1 to about 4:1. The preferred temperature for crystallizing product from the hexane solution is from about 25° C. to about O° C., more preferably from about 10° C. to about 0° C. The crystals are removed from the supernatant liquid, preferably by filtration, dried, preferably under vacuum and at a temperature of less than about 30° C.
In step (c) of the above process, the crystals from step (b) are dissolved in methanol, preferably at a temperature of from about 45° C. to about 65° C., more preferably from about 60° C. to about 65° C. The weight ratio of methanol to solids is from about 20:1 to about 3:1, preferably from about 10:1 to about 4:1. If the resulting solution is not colorless, color can be removed by the addition of activated charcoal and mixing followed by filtration to remove the charcoal.
In step (d), water is added to the methanol solution of step (c) and the resulting mixture is cooled, preferably to a temperature of from about 20° C. to about 0° C., more preferably from about 10° C. to about 0° C. The weight ratio of methanol:water is preferably from about 20:1 to about 3:1, preferably from about 10:1 to about 4:1. The product crystals are removed from the supernatant liquid, preferably by filtration. The crystals are dried, preferably in a vacuum oven at a temperature of less than about 45° C.
The following examples further describe and demonstrate the preferred embodiments within the scope of the subject invention. The examples are given solely for the purpose of illustration, and are not to be construed as limitations of the subject invention, since many variations thereof are possible without departing from its spirit and scope.
EXAMPLES 1-20
Table 1 below is a summary of the production of laboratory-scale (about 30 g product per batch) batches of 4-5'-hexynoyl)-2,6-di-tert-butylphenol produced by reacting 2,6-di-tert-butyl-phenol, 5-hexynoic acid and trifluoroacetic anhydride under various reaction conditions.
In Table 1, the Method number refers to the following procedures:
Method 1: The 5-hexynoic acid and trifluoroacetic anhydride are mixed together with ice cooling. The 2,6-ditert-butylphenol is then added all at once and the reaction mixture is stirred for the time indicated.
Method 2: The 2,6-di-tert-butylphenol and trifluoroacetic anhydride are mixed together at room temperature, and the 5-hexynoic acid is added rapidly. The reaction mixture is stirred for the time indicated.
Method 3: The 2,6-di-tert-butylphenol and 5-hexynoic acid are mixed at room temperature, and the trifluoroacetic anhydride is added at a controlled rate. After addition of the trifluoroacetic anhydride is completed, the reaction mixture is stirred for the indicated time.
Method 4: The 2,6-di-tert-butylphenol and 5-hexynoic acid are dissolved in a solvent. The superscript letter in parenthesis after the 4 indicates the solvent used: (a) hexane, (b) toluene, (c) acetonitrile with phosphoric acid, (d) acetonitrile. The trifluoroacetic anhydride is added at a controlled rate.
The Ratio indicated for each Example in Table 1 is the molar ratio of total amounts of 5-hexynoic acid:2,6-di-tert-butyl-phenol:trifluoroacetic anhydride added to the mixture.
The Temp. indicated for each Example in Table 1 is the maximum temperature reached by the reaction mixture during the reaction. For the Examples where the third reactant is added all at once or rapidly, the reaction temperature comes to the indicated peak temperature and then slowly cools throughout the reaction time. For the Examples of Methods 3 and 4 where the trifluoroacetic anhydride is added at a controlled rate, a temperature close to that indicated is maintained throughout the addition, and then the reaction mixture is allowed to cool slowly. Example 19 differs in that the 50° C. temperature is maintained throughout the 5-hour time of stirring by heating.
After completion of the reaction, the contents of the reaction mixture are analyzed to determine (1) the amount of 2,6-di-tert-butylphenol remaining, (2) the amount of 4-(5'-hexynoyl)-2,6-di-tert-butylphenol produced, and (3) other products of the reaction. The percent Conversion shown in Table 1 is 100 minus the percent of unreacted 2,6-di-tert-butyl-phenol (based on the starting amount of this reactant). The percent Selectivity shown in Table 1 is the percent of desired product to total products in the completed reaction mixture.
TABLE 1______________________________________ Con- Selec- Temp. Time version tivityExample Method Ratio (°C.) (hrs) (%) (%)______________________________________ 1 1 1.3:1.0:1.5 23 3 100 93 2 1 1.0:1.0:1.1 0 2.5 77 98 3 1 1.0:1.0:1.1 55 2.5 99 81 4 1 1.1:1.0:1.3 23 1.3 98 92 5 1 1.1:1.0:1.3 23 1.3 99 94 6 2 1.1:1.0:1.3 65 0.75 99 84 7 2 1.2:1.0:1.3 63 0.33 99 89 8 3 1.1:1.0:1.3 75 0.25 99 84 9 3 1.1:1.0:1.1 36 3 99 9610 3 1.1:1.0:1.0 78 0.25 98 9911 3 1.0:1.1:1.0 83 3 93 9612 3 1.0:1.1:1.0 102 1.5 96 8013 3 1.0:1.0:1.0 80 0.33 98 8614 3 1.0:1.0:1.0 68 1 99 8715 4.sup.(a) 1.0:1.0:1.0 62 0.5 97 9116 4.sup.(a) 1.0:1.0:1.0 50 1 98 8717 4.sup.(b) 1.0:1.0:1.0 23 22 84 8118 4.sup.(c) 1.0:3.0:3.7 31 2 100 9019 4.sup.(d) 1.1:1.0:1.0 50 5 86 9220 3 1.0:1.0:0.5 35 22 80 98______________________________________
EXAMPLE 21
Method 3 above is used to produce 4-(4'-pentynoyl)-2,6-di-tert-butylphenol by reacting 2,6-di-tert-butylphenol and 4-pen-tynoic acid and trifluoroacetic anhydride at a molar ratio of 1.0:1.0:1.0 at a maximum temperature of 36° C. with a reaction time of 2 hours after addition of the trifluoroacetic anhydride.
EXAMPLE 22
Method 3 above is used to produce 4-(4',5'-hexadienoyl)-2,6-di-tert-butylphenol by reacting 2,6-4,5-hexadienoic acid and trifluoroacetic anhydride at a molar ratio of 1.0:1.0:1.0 at a maximum temperature of 56° C. with stirring for 2 hours after addition of the trifluoroacetic anhydride.
EXAMPLE 23
Method 3 above is used to produce 4-(10,-undecynoyl)-2,6-di-tert-butylphenol by reacting 2,6-di-tert-butylphenol with 10-undecynoic acid and trifluoroacetic anhydride at a molar ratio of 1.0:1.0:1.0 at a maximum temperature of 45° C. with stirring for 2 hours after addition of the trifluoroacetic anhydride.
EXAMPLE 24
The following is an exemplary synthesis and purification of 4-(5'-hexynoyl)-2,6-di-tert-butylphenol using a process of the subject invention.
2,6-Di-tert-butylphenol (5496 g, Ethyl Corp.) is melted on a warm water bath and charged into a 50L three-neck, round-bottom flask equipped with an air driven stirrer, stir shaft, large Teflon stirring paddle, addition funnel, thermometer, and reflux condenser. The apparatus is assembled in a stainless steel cooling bath. To the gently stirred liquid is added 5-hexynoic acid (3288 g, Farchan Laboratories). Trifluoroacetic anhydride (5872 g, Halocarbon Inc.) is added through the addition funnel at such a rate to keep the reaction temperature at 40°-45° C. throughout the time of addition. After the addition, which requires about 1 hour, the resulting solution is stirred an additional hour at 30°-40° C. The reaction mixture is diluted with 52L of hexane, extracted twice with 20L of 5% potassium carbonate, once with 20L of water, and then treated with 400 g of Darco G-60 activated carbon at reflux for 15 minutes. The hot mixture is filtered through Celite, washed with 800 mL of hexane, and concentrated to a final volume of 36 L on a rotary evaporator. Crystallization with slow agitation at 0°-3° C. followed by filtration and drying in a vacuum oven at 40°-45° C. gives 5960 g of crude product. The crude product (5935 g) is dissolved in 29.6 L of methanol and treated at reflux for 15 minutes with 550 g of activated carbon. The hot mixture is filtered through Celite. Water (5830 mL) is added. Crystallization is accomplished with slow agitation in an ice bath. Filtration gives 5140 g of purified product, after drying in a vacuum oven at 40°-45° C. and 27-28 in Hg.
While particular embodiments of the subject invention have been described, it will be obvious to those skilled in the art that various changes and modifications to the processes disclosed herein can be made without departing from the spirit and scope of the invention. It is intended to cover, in the appended claims, all such modifications that are within the scope of this invention.
|
The subject invention relates to a process for the preparation of 2-alkyl-4-acyl-6-tert-butylphenol compound having the chemical structure: ##STR1## wherein -R is an aliphatic group having a terminally unsaturated moiety selected from --C.tbd.CH and --CH═C═CH 2 , and R' is selected from saturated, straight, branched or cyclic alkyl having from 1 to about 10 carbon atoms; the 2-alkyl-4-acyl-6-tert-butylphenol compound being produced in a reaction mixture comprising the corresponding 2-alkyl-6-tert-butylphenol: ##STR2## the corresponding carboxylic acid: RCOOH, and trifluoroacetic anhydride.
| 2
|
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention pertains to electric arc furnaces. More particularly, the present invention concerns gaseous atmospheres for electric arc furnaces. Even more particularly, the present invention concerns inert atmospheres for electric arc furnaces.
II. Prior Art
The manufacture of steel and alloys thereof, such as stainless steel, is well documented. There are a plurality of methods used to prepare iron and alloys thereof, such as steel, stainless steel as well as esoteric iron alloys. Steel, differs from pig iron and other forms of iron which are ordinarily manufactured, by a reduced carbon content. As is known to those skilled in the art to which the present invention pertains there are a plurality of methods currently known for the manufacture of steel. One such method is the open hearth method wherein pig iron, along with a certain amount of scrap iron, is deposited in a furnace hearth wherein a gas and air mixture is burned over the iron. The gas burned in the furnace generates a waste gas which are discharged up a chimney flue. However, before being discharged gases give off a considerable proportion of their heat to brick-lined heating chambers. The chambers, which are formed of refractory bricks, are, thus, heated to red hot temperatures. After the bricks reach the elevated temperature the gas flow is reversed and the mixture of gas and air is admitted through the heating chambers from which it absorbs heat. This preheating of the gas and air enables the combustion temperature of the flame to be considerably raised. The burning of the gas and air mixture above the pig iron causes an oxidation reaction to produce the steel.
Another method of steel manufacture is the Bessemer process. Yet another method is the oxygen steel-making process. Another form of steel manufacture, wherein mild steels of exceptionally high purity are manufactured, is the electric process. According to this process there is no air employed. In steel making with electric arc furnaces the requisite heat for the refining of the steel (sometimes pig iron) is supplied, not by the burning of gas or coal, but by an electric current. The heat is produced by an electric arc which is formed between a number of carbon electrodes and the surface of the molten bath. Rather than employing a combustive air for oxidizing the undesirable admixtures in the furnace, iron oxides are added, which give off their oxygen. In carrying out an electric arc steel manufacturing process an inert atmosphere is employed within the furnace.
The electric arc furnace operates on the principle of electric arc discharge. Ordinarily, this is allied to a gas discharge which takes place when electricity is passed through rearified gases. The arc discharge occurs when two carbon electrodes are brought into contact with each other and are then moved apart. Ordinarily, just before the carbon rods separate and direct material contact between them is broken, a high electric resistance is developed to the extent that the tips of the carbon electrodes begin to glow. This is associated with the emission of electrons which, because of the high emission temperatures, produces a high degree of ionization of the air. As a result of this ionization, the air in the immediate vicinity of the carbon tips becomes conductive to electricity, so that the current will continue to flow when the electrodes are no longer actually touching each other. The bombardment of electrons to which it is exposed causes the positive elctrode, in particular, to become white hot and a crater forms at its tip. In the actual arc itself, the gas molecules of the air dissociate. In electric furnaces, per se, the intense heat developed by the arc discharges utilized for the melting of metals. If the material to be melted is a poor conductor of electricity, the heat radiated by the arc formed between two carbon electrodes is used to melt it. On the other hand, if the material does conduct electricity, then the arc discharger may either be passed directly from the electrodes to the material or the electrodes may actually be buried in the material. In either case though, the considerable heat developed in the electrodes helps the current to generate heat in the material and thus attain the melting temperature. In the manufacture of steel, however, because it is a good conductor of electricity, the electrodes are placed above the material, i.e., the pig iron or steel.
Ordinarily, an inert atmosphere of nitrogen is employed in electric arc furnaces. By utilizing an atmosphere of rarified gas, having a higher heat retention content, it is reasoned that a longer electrode life with a decrease of energy input as well as a resulting higher quality molten metal and faster melt down time can be achieved. The present invention, as will subsequently be detailed, seeks to provide to improve inert atmospheres for conducting electric arc furnace manufacture of steel.
SUMMARY OF THE INVENTION
In accordance with the present invention an inert atmosphere for utilization in an electric arc furnace for the manufacture of copper or steel is selected from the group consisting of carbon dioxide, argon, carbon dioxide and argon or a mixture of nitrogen and carbon dioxide.
Where the mixture of carbon dioxide and argon is employed, the carbon dioxide is present in an amount ranging from about ten to about ninety percent, by volume, and the argon is present in an amount ranging from about ninety percent to about ten percent, by volume. Likewise, where the mixture of nitrogen and carbon dioxide is employed, the amount ranges from about ten to about ninety percent of nitrogen, by volume, and the carbon dioxide is present, in an amount, ranging from about ninety to about ten percent, by volume. Preferably, where a mixture of gases is employed each of the gases is present in a one to one volumetric ratio.
Where carbon dioxide is employed as the inert atmosphere, the gaseous carbon dioxide is admitted to the furnace to purge it of any other gases. After the furnace has been purged, this arc between the electrodes is increased as the current rises. The carbon dioxide atmosphere is maintained throughout the melt down process. The amount of gaseous carbon dioxide introduced is equal to that lost from leakage in the furnace.
The other gaseous systems are employed in precisely the same manner.
For a more complete understanding of the present invention reference is made to the following detailed description.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, electric arc furnaces for the manufacture of copper, steel and other iron alloys, employ an inert atmosphere therewithin selected from the group consisting of carbon dioxide, argon, a mixture of carbon dioxide and argon or a mixture of nitrogen and carbon dioxide. Each of the atmospheres can be utilized in the electric arc furnace with equal efficacy. Each of the atmospheres employed herein has a higher quality heat content, expressed in calories or BTU's than a conventional nitrogen atmosphere. Furthermore, each of the atmospheres has a less oxygen content than would ordinarily be present in a commercially available nitrogen atmosphere. The consequence of these two factors results in a longer electrode life, a decrease in the energy input prerequisite to maintain the temperatures within the furnace. Because of the reduced oxygen present there is a higher quality in the molten metal as well as a faster meltdown time.
For example, the normal heat content of a nitrogen atmosphere is expressed as Cp=6.5+0.001 T°K., as calories per degree (K.) per mole. On the other hand, a carbon dioxide system evidences a specific content of 10.34+0.001 T6°K. An argon system evidences a specific heat of 4.97 calories per degree (°K.) per mole. The carbon dioxide and argon system, of course, is determined on a percentage molar basis, and varies depending on the volumetric ratios of the gases employed. The nitrogen and carbon dioxide system also, evidences a higher heat value than normal nitrogen atmospheres. Generally, the specific heat value of the nitrogen and carbon dioxide system will vary according to the molar proportion employed.
Where carbon dioxide and argon, alone, comprise the atmosphere in which the electric arc furnace steel making process is conducted, the atmosphere is substantially one hundred percent of the pure gas.
Where the atmosphere consists essentially of carbon dioxide and argon, each of the elements is present, in a percentage ranging from about ten to about ninety percent, by volume. Preferably, the carbon dioxide is present in an amount ranging from about twenty-five to about fifty percent, by volume, and the argon is present in an amount ranging from about fifty to about seventy-five percent, by volume.
Where nitrogen and carbon dioxide is present, the nitrogen is present in an amount ranging from about ten to about ninety percent, by volume and the carbon dioxide is present in an amount ranging from about ten to about ninety percent, by volume. Preferably, the nitrogen and carbon dioxide are each present in an amount of about fifty percent, by volume.
In deploying each of the atmospheres, the same procedure is employed. Generally speaking the furnace is purged of any residual gases by the introduction thereinto of the selected gaseous atmosphere. The furnace is purged by flowing the selected atmosphere therethrough. Then, when the atmosphere comprises 100 percent of the selected inert gas in accordance herewith, the electrodes are brought into contact, and an electric current is then caused to flow to the electrodes. At the preselected current, the electrodes are then gradually moved apart.
As the electrodes are moved apart an arc is generated between the electrodes. Because of the conduction of the molten metal an arc is generated therebetween as well as to effectuate the further melting thereof to cause the refinement of the low grade steel.
As the melting process and refining process continues on, the atmosphere of the inert gas is maintained by the flow thereinto through any conventional means. The amount of atmosphere introduced into the furnace is equal to the amount which is lost through a leakage or the like.
As indicated hereinabove, because of the purity as well as the heat content of the atmosphere hereof, there is a longer electrode life and a faster meltdown time. Also, as a consequence hereof there is a decrease in the energy input necessary to maintain the heat values within the atmosphere as well as a higher quality molten metal.
It should be noted that the pure form of the gases, i.e. a one hundred percent argon atmosphere produces a higher grade of purity in the steel, as opposed to a gaseous mixture of argon and carbon dioxide. In order, the highest purity is derived from an argon atmosphere, followed by the argon-carbon dioxide atmosphere; next, the nitrogen and carbon dioxide atmosphere and finally the carbon dioxide atmosphere. Yet, everyone of these atmospheres produces a higher quality metal than a one hundred percent nitrogen atmosphere.
|
An inert atmosphere for electric arc furnaces is either carbon dioxide, argon, a mixture of carbon dioxide and argon or a mixture of nitrogen and carbon dioxide. The inert gas atmosphere is utilized in the manufacture of high alloy or stainless steels, as well as in the manufacture of copper.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to the cleaning of spinnerette jets of a solvent-spun fibre production plant.
In the manufacture of solvent-spun fibres, such as for example Teneel cellulose fibres (Teneel is a trade mark of Courtaulds Fibres Limited), a dope comprising wood pulp dissolved in an aqueous solution of amine oxide, is pumped through a series of filters to a plurality of spinning heads. Each spinning head comprises a plurality of very thin metal plates in which thousands of spinnerette jet holes are punched. The jet holes are typically of the order of 80μ and are of trumpet shape.
It is vitally important to prevent the jets becoming blocked and to this extent a tremendous reliance is placed on designing filters upstream of the jets to filter the dope. Nevertheless there comes a time when it is necessary to dismantle the spinning head and clean the spinnerette jets.
In the past, the Spinnerette jets have been cleaned by soaking the spinnerette plates in hot demineralised water to regenerate the cellulose. Most of the dope can be removed this way, however, a number of jet holes remain blocked. The remaining blocked holes are usually cleaned by a combination of the use of steam cleaning, high power ultrasonic washing with water and the use of trichlorethylene ultrasonic treatment, and extremely careful inspection. The trichlorethylene ultrasonic treatment is an important stage in the present processes, but it is a relatively toxic part of the process and there is the need to reduce dependency on the use of trichlorethylene for this part of the process.
There is, therefore, a need for a reliable method of cleaning which is less dependent on the skills of inspectors searching thousands of jet holes for blockages to detect blocked holes, and which will not damage the spinnerette plates.
An object of the present invention is to provide a safe and reliable method of cleaning spinnerette jets of a spinning head of a solvent-spun fibre manufacturing plant.
BRIEF SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided a method of cleaning and unblocking dope from jet holes in a spinnerette plate of a spinning head of a solvent-spun cellulose fibre manufacturing plant, the method comprising the steps of:
(a) scraping the bulk of the dope from the spinnerette plates,
(b) soaking the spinnerette plate in the same solvent as used to make the dope,
(c) causing the solvent to flow through the jet holes in a first direction,
(d) causing the solvent to flow through the jet holes in the reverse direction to that of the first direction,
(e) ultrasonically washing the solvent from the plates in hot demineralised water,
(f) steam cleaning to remove regenerated residual cellulose from the jet holes,
(g) ultrasonically washing the spinnerette plates in a cleaning agent which affects the physical properties of the regenerated cellulose rendering it more easy to dislodge the cellulose from the jet holes by the action of ultrasonic washing, and
(h) ultrasonically washing regenerated cellulose from the jet holes.
In the case where the dope comprises an aqueous solution of cellulose in amine oxide, and the solvent used in steps (b), (c) and (d) is hot amine oxide.
Preferably the cleaning agent is a chlorinated hydrocarbon such as trichlorethylene.
According to a further aspect of the present invention there is provided apparatus for cleaning and unblocking dope from spinnerette jet holes of a spinnerette which is used in the manufacture of solvent-spun fibres, the apparatus comprising a vessel in which the spinnerette to be cleaned is mounted, the vessel having a first pipe connected to the vessel on one side of the spinnerette, a second pipe connected to the vessel on the other side of the spinnerette, and a bypass pipe which interconnects the internal volume of the vessel one side of the spinnerette with the internal volume of the vessel on the other side of the spinnerette, a tank for receiving solvent for the dope, a source of supply of solvent for the dope, a first three way valve having a first port connected to the source of supply by a third pipe, a second port connected to the vessel by way of the first pipe and a third port connected to the tank by way of a fourth pipe, the first valve being selectively movable to a first position where the first valve connects the source of supply of solvent to the vessel by way of the first pipe or to a second position where the first valve connects the vessel to the tank by way of the second pipe, a second valve having a first port connected to the source of supply by way of a fifth pipe, a second port connected to the vessel byway of the second pipe and a third port connected to the tank by way of a sixth pipe, the second valve being selectively movable to a first position where the second valve connects the source of supply of solvent to the vessel by way of the sixth pipe or to a second position where the second valve connects the vessel to the tank by way of the second pipe, and a third valve in the bypass pipe and operable to open or close the bypass pipe.
Preferably a means is provided for ultrasonically washing solvent from the plates in hot demineralised water.
Preferably steam cleaning means are provided for removing regenerated cellulose from the jet holes.
In the case where spinnerette plates used for the manufacture of cellulose fibres, a washing means is provided for ultrasonically washing cellulose remnants from the plates with a cleaning agent which affects the physical properties of the regenerated cellulose rendering it more easy to dislodge the cellulose from the jet holes by the action of ultrasonic washing.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by way of an example with reference to the accompanying drawings in which:
FIG. 1 shows schematically a cross-sectional view through a spinning head of a solvent-spun fibre manufacturing plant showing the spinnerette plates which require to be cleaned,
FIG. 2 shows an enlarged view of three spinnerette jet holes of the spinning head of FIG. 1,
FIG. 3 shows schematically a block diagram flow chart of a method of cleaning the components of the spinning head shown in FIG. 1 in accordance with the present invention, and
FIG. 4 shows schematically apparatus for carrying out the solvent washing part of the method of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1 there is shown a spinning head 10 comprising a top housing 11 which is bolted to a bottom housing 12 and a spinnerette 15 which comprises six spinnerette plates 13, each of which has of the order of 3,000 spinnerette jet holes punched through the plates. The plates are about 1.4 mm thick. Each jet hole 14 (three of which are shown enlarged in FIG. 2) is 80μ diameter.
The spinnerette 15 has flanges 15a projecting normal to the plates 13 these flanges extend around the perimeter of the plates and act to support a perforated support plate 17 on which a single stainless steel 2-ply mesh filter 18 of 35μ to 37μ particle retention. The support plate 17 supports the filters 18 against the high pressure of the dope on the filters 18. Furthermore, the flanges 16 also provide local stiffness to assist the plates 13 from bowing under the pressure of dope exerted on the plates 13.
When the spinning head 10 is removed from the fibre production line for cleaning, the dope (typically an aqueous solution of wood pulp in amine oxide) congeals on the filters 18 and the plates 13 completely blocking the jet holes 14.
The spinning heads 10 must be disassembled whilst hot when the dope is still mobile to aid removal of the dope. Therefore the dirty components are kept hot in a heated enclosure 19 (see FIG. 3). The top housing 11 is separated from the bottom housing 12 and is scraped clean (step 20) and left to soak in hot demineralised water bath 21 (see FIG. 3) (typically 60° C.). During soaking, cellulose regenerates and shrinks; after a time the regenerated cellulose can be easily removed.
The support plate 17 is removed from the housing and it too is scraped to remove congealed dope and left to soak in hot (60° C.) demineralised water in bath 21.
The filter elements 18 are washed then thrown away.
Excess dope is very carefully scraped away from the plates 13 (step 20) but small amounts of dope congeal and remain blocking the jet holes 14 and cannot be removed by scraping.
After soaking, the top and bottom housings 11, 12 are steam cleaned using a steam gun 22. The components are then dried and then inspected at station 143.
The spinnerette 15 is mounted in a solvent washing rig 24 as shown in FIG. 4.
Referring to FIG. 4 the solvent washing rig 24 comprises a sealable vessel 25 having confronting flanges 26, 27. The spinnerette 15 is mounted in the vessel 25 with the flange 15(a) of the spinnerette clamped between the flanges 26, 27 to make a fluid tight seal. The lower part of vessel 25 has a solid rod 28 welded onto the face of flange 27 which prevents the spinnerette 15 being too tightly clamped.
The vessel 25 is provided with two pipes. 29, 30; one of the pipes 29 is connected to the vessel 25 at one side of the spinnerette 15 and the other pipe 30 is connected to the vessel at the other side of the spinnerette 15.
Hot amine oxide (110° C.) from a sump tank 31 is pumped by a pump 32 through pipes 33, 34 to two mechanically interconnected valves 35, 36.
Valve 35 has three connections; the first connects to the source of supply of hot amine oxide via pipe 33, the second connects to the vessel 25 through pipe 29 and the third connects to the tank 31 via pipe 37. The valve 35 has two operating positions. In the first position it connects pipe 33 to pipe 29; in the second position it connects pipe 29 to pipe 37.
Valve 36 has three connections; the first connects to the source of supply of hot amine oxide via pipe 34, the second connects to the vessel 25 through the pipe 30 and the third connects to the tank 31 through a pipe 38. The valve 36 has two operating positions. In the first position it connects pipe 34 to the vessel 25 via pipe 30; in the second position it connects pipe 30 to the tank 31 via pipe 38.
The vessel 25 is provided with a bypass pipe 39 interconnecting the volumes of the vessel 25 each side of spinnerette 15 via a valve 40.
In operation, the valve 35 is set to supply hot amine oxide to the vessel 25 through pipes 33 and 29 and the bypass valve 40 is opened. Valve 36 is set to connect pipe 30 to the sump tank 31 via pipe 38, Hot amine oxide is circulated through vessel 25 to soak the plates 13 without forcing a flow through the spinnerette jet holes 14. The plates are soaked in this way for about 15 to 30 minutes.
The valve 40 is then closed to cause the hot amine oxide to flow through the spinnerette jet holes in plates 13 to the sump tank 31.
After stopping the pump 32 the valve 35 is then set to connect pipe 34 to pipe 30 and valve 35 is set to connect pipe 29 to the sump tank 31 via pipe 37. Hot amine oxide is then circulated in the reverse direction through the spinnerette jet holes 14 to the sump tank.
After the spinnerette plates 13 have been thoroughly washed with hot amine oxide, the pump is stopped to allow hot AO to drain to the sump. The vessel 25 is opened and the spinnerette 15 is removed. The spinnerette is washed in a water ultrasonic bath 41. The plates 13 are then steam cleaned with a steam gun 22, dried and washed in trichlorethylene in the ultrasonic bath 42 (see FIG. 3). The spinnerette 15 is dried and inspected at station 43. The inspection station comprises a background lighting source over which the plates 13 to be inspected are placed. A skilled inspector checks to see if any of the jet holes 14 are still blocked and, if .necessary, dislodges the blockage with a fine probe (step 44) or returns the spinnerette to the steam cleaning stage 22 and ultrasonic cleaning in the trichlorethylene bath 42. When the spinnerette is pronounced clean at inspection it is then treated in a trichlorethylene ultrasonic bath 45 as a final polishing.
The spinning head is reassembled at station 46 using the cleaned housings 11, 12 and clean spinnerette 15 and support plate 17 and fresh filter gauze 18 and seals are used. The assembled spinning head 10 is then brought up to operating temperatures when needed for replacement in the fibre production plant by placing it in a heated enclosure 47.
|
A method and apparatus for cleaning and unblocking dope from jet holes (14) of a spinnerette plate (13) used in the manufacture of solvent-spun cellulose fibre. The method comprises the steps of soaking the spinnerette plates (12) in a solvent for the dope, flushing the solvent in a first direction through the jet holes (14) flushing the solvent in the reverse direction through the jet holes 14. The solvent is washed off in a water ultrasonic bath. The spinnerette plates are then steam cleaned and then ultrasonically cleaned in a cleaning agent which will dislodge remnants of cellulose from the spinnerette plates 13.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of U.S. application No. 09/788,365 entitled GAS INJECTION SYSTEM FOR PLASMA PROCESSING, filed on Feb. 21, 2001 now U.S. Pat. No. 7,785,417 which is a continuation application of U.S. application No. 09/223,273, filed Dec. 30, 1998 now U.S. Pat. No. 6,230,651, the entire content of each is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a system and a method for delivering reactants to a substrate in a plasma processing system for semiconductor substrates such as semiconductor wafers. More particularly, the present invention relates to a system and a method for delivering reactants via a gas injection system to maximize processing uniformity and efficiency.
BACKGROUND OF THE INVENTION
Vacuum processing chambers are generally used for etching or chemical vapor depositing (CVD) of materials on substrates by supplying process gas to the vacuum chamber and applying a radio frequency (RF) field to the gas. Showerhead gas injection and diffusive transport systems are commonly used to ensure even distribution over the substrate.
U.S. Pat. No. 4,691,662 to Roppel et al. discloses a dual plasma microwave apparatus for etching and deposition in which process gas is fed by conduits mounted on a side wall of a processing chamber, extending over a portion of the substrate. U.S. Pat. No. 5,522,934 to Suzuki et al. discloses a gas injector arrangement including a plurality of gas supply nozzles positioned in a plurality of levels in a direction substantially perpendicular to the substrate. The gas supply nozzles at upper levels extend further toward the center of the substrate than those at lower levels. The injection holes are located at the distal ends of the gas supply nozzles. These systems are effective in delivering the process gas to the region above the substrate. However, because the conduits extend over the substrate surface between the substrate and the primary ion generation region, as the ions diffuse from the generation region toward the substrate the conduits can cast shadows of ion nonuniformity onto the substrate surface. This can lead to an undesirable loss in etch and deposition uniformity.
Other approaches employ gas supply conduits which do not extend over the substrate surface. “Electron Cyclotron Resonance Microwave Discharges for Etching and Thin-film Deposition,” J. Vacuum Science and Technology A, Vol. 7, pp. 883-893 (1989) by J. Asmussen shows conduits extending only up to the substrate edge. “Low-temperature Deposition of Silicon Dioxide Films from Electron Cyclotron Resonant Microwave Plasmas,” J. Applied Physics, Vol. 65, pp. 2457-2463 (1989) by T. V. Herak et al. illustrates a plasma CVD tool including a plurality of gas injection conduits which feed separate process gases. One set of conduits is mounted in the lower chamber wall with gas delivery orifices located just outside the periphery of the substrate support and at the distal ends of the conduits. These conduit arrangements can cause process drift problems as a result of heating of the ends of the conduits.
“New Approach to Low Temperature Deposition of High-quality Thin Films by Electron Cyclotron Resonance Microwave Plasmas,” J. Vac. Sci. Tech, B, Vol. 10, pp. 2170-2178 (1992) by T. T. Chau et al. illustrates a plasma CVD tool including a gas inlet conduit mounted in the lower chamber wall, located just above and outside the periphery of the substrate support. The conduit is bent so that the injection axis is substantially parallel to the substrate. An additional horizontal conduit is provided for a second process gas. The gas injection orifices are located at the distal ends of the conduits. Injectors with the orifices located at the distal ends of the injector tubes may be prone to clogging after processing a relatively small batch of substrates, e.g., less than 100. This injector orifice clogging is detrimental as it can lead to nonuniform distribution of reactants, nonuniform film deposition or etching of the substrate, and shifts in the overall deposition or etch rate.
Various systems have been proposed to improve process uniformity by injecting process gas at sonic or supersonic velocity. For example, U.S. Pat. No. 4,270,999 to Hassan et al. discloses the advantage of injecting process gases for plasma etch and deposition applications at sonic velocity. Hassan et al. notes that the attainment of sonic velocity in the nozzle promotes an explosive discharge from the vacuum terminus of the nozzle which engenders a highly swirled and uniform dissipation of gas molecules in the reaction zone surrounding the substrate. U.S. Pat. No. 5,614,055 to Fairbairn et al. discloses elongated supersonic spray nozzles which spray reactant gas at supersonic velocity toward the region overlying the substrate. The nozzles extend from the chamber wall toward the substrate, with each nozzle tip having a gas distribution orifice at the distal end. U.S. Pat. No. 4,943,345 to Asmussen et al. discloses a plasma CVD apparatus including supersonic nozzles for directing excited gas at the substrate. U.S. Pat. No. 5,164,040 to Eres et al. discloses pulsed supersonic jets for CVD. While these systems are intended to improve process uniformity, they suffer from the drawbacks noted above, namely clogging of the orifices at the distal ends of the injectors, which can adversely affect film uniformity on the substrate.
U.S. Pat. No. 4,996,077 to Moslehi et al. discloses an electron cyclotron resonance (ECR) device including gas injectors arranged around the periphery of a substrate to provide uniform distribution of non-plasma gases. The non-plasma gases are injected to reduce particle contamination, and the injectors are oriented to direct the non-plasma gas onto the substrate surface to be processed.
U.S. Pat. No. 5,252,133 to Miyazaki et al. discloses a multi-wafer non-plasma CVD apparatus including a vertical gas supply tube having a plurality of gas injection holes along a longitudinal axis. The injection holes extend along the longitudinal side of a wafer boat supporting a plurality of substrates to introduce gas into the chamber. Similarly, U.S. Pat. No. 4,992,301 to Shishiguchi et al. discloses a plurality of vertical gas supply tubes with gas emission holes along the length of the tube. These patents relate to thermal, non-plasma CVD, and are thus not optimized for plasma processing.
As substrate size increases, center gas injection is becoming increasingly important for ensuring uniform etching and deposition. This is particularly evident in flat panel display processing. Typically, diffusive transport is dominant in the region above the substrate in these low pressure processing systems, while convective transport plays much less of a role. Near the injection orifices, however, convective transport can dominate diffusive transport because of the jet-like nature of the injected gas. Locating the injection orifices closer to the substrate therefore increases the convective transport in relation to the otherwise dominant diffusive transport above the substrate. Conventional showerhead gas injection systems can deliver gases to the center of the substrate, but in order to locate the orifices close to the substrate, the chamber height must be reduced which can lead to an undesirable loss in ion uniformity.
Radial gas injection systems may not provide adequate process gas delivery to the center of large area substrates typically encountered, for example, in flat panel processing. This is particularly true in bottom-pumped chamber designs commonly found in plasma processing systems. Without a means for center gas feed, etch by-products may stagnate above the center of the substrate, which can lead to undesirable nonuniform etching and profile control across the substrate.
The above-mentioned Fairbairn et al. patent also discloses a showerhead injection system in which injector orifices are located on the ceiling of the reactor. This showerhead system further includes a plurality of embedded magnets to reduce orifice clogging. U.S. Pat. No. 5,134,965 to Tokuda et al. discloses a processing system in which process gas is injected through inlets on the ceiling of a processing chamber. The gas is supplied toward a high density plasma region. This system employs microwave energy and is not optimized for radio frequency plasma processing. U.S. Pat. No. 5,522,934 to Suzuki et al. disclose a system where inert (rather than process) gas is injected through the center of the chamber ceiling.
In addition to the systems described above, U.S. Pat. No. 4,614,639 to Hegedus discloses a parallel plate reactor supplied with process gas by a central port having a flared end in its top wall and a plurality of ports about the periphery of the chamber. U.S. Pat. Nos. 5,525,159 (Hama et al.), 5,529,657 (Ishii), 5,580,385 (Paranjpe et al.), 5,540,800 (Qian) and 5,531,834 (Ishizuka et al.) disclose plasma chamber arrangements supplied process gas by a showerhead and powered by an antenna which generates an inductively coupled plasma in the chamber.
There is thus a need for optimizing uniformity and deposition for radio frequency plasma processing of a substrate while preventing clogging of the gas supply orifices and build up of processing by-products and improving convective transport above the wafer.
SUMMARY OF THE INVENTION
The invention provides a plasma processing system which includes a plasma processing chamber, a vacuum pump connected to the processing chamber, a substrate support supporting a substrate within the processing chamber, a dielectric member having an interior surface facing the substrate support, wherein the dielectric member forms a wall of the processing chamber, a gas injector extending through the dielectric member such that a distal end of the gas injector is exposed within the processing chamber, the gas injector including a plurality of gas outlets supplying process gas into the processing chamber, and an RF energy source which inductively couples RF energy through the dielectric member and into the chamber to energize the process gas into a plasma state to process the substrate. The system is preferably a high density plasma chemical vapor deposition system or a high density plasma etching system.
The RF energy source can comprise an RF antenna and the gas injector can inject the process gas toward a primary plasma generation zone in the chamber. The gas outlets can be located in an axial end surface of the gas injector. For instance, the gas outlets can include a center gas outlet extending in an axial direction perpendicular to the exposed surface of the substrate and a plurality of angled gas outlets extending at an acute angle to the axial direction. The gas injector can inject the process gas at a subsonic, sonic, or supersonic velocity. In one embodiment, the gas injector includes a planar axial end face which is flush with the interior surface of the dielectric window. In another embodiment, the gas injector is removably mounted in the dielectric window and/or supplies the process gas into a central region of the chamber. The gas outlets can have various configurations and/or spatial arrangements. For example, the gas injector can include a closed distal end and the gas outlets can be oriented to inject process gas at an acute angle relative to a plane parallel to an exposed surface of the substrate. In the case where the gas injector is removably mounted in the opening in the dielectric window, at least one O-ring provides a vacuum seal between the gas injector and the dielectric window. Various types of plasma generating sources can be used. For instance, the RF energy source can comprise an RF antenna in the form of a planar or non-planar spiral coil and the showerhead nozzle injects the process gas toward a primary plasma generation zone in the chamber.
The invention also provides a method of plasma processing a substrate comprising placing a substrate on a substrate support in a processing chamber, wherein an interior surface of a dielectric member forming a wall of the processing chamber faces the substrate support, supplying process gas into the processing chamber from a gas injector extending through the dielectric member such that a distal end of the gas injector is exposed within the processing chamber, the gas injector including a plurality of gas outlets supplying process gas into the processing chamber, and energizing the process gas into a plasma state by inductively coupling RF energy produced by the RF energy source through the dielectric member into the processing chamber, the process gas being plasma phase reacted with an exposed surface of the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a plasma processing system in accordance with the present invention;
FIGS. 2 a and 2 show gas distribution effects in an inductively coupled plasma reactor, FIG. 2 a showing the effects using a gas injection arrangement in accordance with the present invention and FIG. 2 ba showing the effects using a conventional gas ring arrangement;
FIGS. 3 a - c show details of a gas injector design in accordance with the invention, FIG. 3 a , showing a cross section of the gas injector, FIG. 3 b showing .a perspective view of the gas injector and FIG. 3 c showing an axial cross-sectional view of the gas injector;
FIG. 4 is a graph of local SiCl x emission from a 300 mm LAM TCP™ plasma reactor fitted with a gas injector providing top gas injection according to the present invention compared to the same reactor fitted with a gas ring providing side gas injection;
FIG. 5 is a graph of chlorine atom distribution from a 300 mm LAM TCP™ plasma reactor fitted with a gas injector providing top gas injection according to the present invention;
FIGS. 6 a - c are SEM (scanning electron microscope) images of etch profiles in polysilicon dense lines and FIGS. 6 d - f are SEM (scanning electron microscope) images of etch profiles in polysilicon isolated lines;
FIGS. 7 a - d are SEM (scanning electron microscope) images of etch profiles in polysilicon dense lines and isolated lines across a 300 mm wafer processed in a reactor operated fitted with a top gas injector in accordance with the invention; and
FIGS. 8 a - d are SEM (scanning electron microscope) images of etch profiles in polysilicon dense lines and isolated lines across a 300 mm wafer processed in a reactor and fitted with side gas injection.
FIG. 9 shows an alternate embodiment of a gas injector in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an improved gas injection system for plasma processing of substrates such as by etching or CVD. The injection system can be used to inject gases such as gases containing silicon, halogen (e.g., F, Cl, Br, etc.), oxygen, hydrogen, nitrogen, etc. The injection system can be used alone or in addition to other reactant/inert gas supply arrangements.
According to a preferred embodiment of the invention, a gas injection arrangement is provided for an inductively coupled plasma chamber. In the preferred arrangement, a gas injector is centrally located in an upper wall of the chamber and one or more gas outlets direct process gas into the chamber above a semiconductor substrate to be processed. The gas injector in accordance with the invention can improve etch uniformity, center-to-edge profile uniformity, critical dimension (CD) bias and/or profile microloading.
The gas outlets can be provided in a surface of the gas injector which is below, flush or above the surface of the upper chamber wall. For example, the gas injector can comprise a cylindrical member having gas outlets in an axial end thereof located between the upper wall and the exposed surface of the semiconductor substrate. In accordance with the invention, improved etch results can be achieved with a single gas injector located centrally in the upper chamber wall. However, more than one gas injector can be provided in the upper wall of the chamber, especially in the case where the plasma is generated by an antenna separated from the interior of the chamber by a dielectric layer or window.
The number of gas outlets and/or the angle of injection of gas flowing out of the gas outlets can be selected to provide desired gas distribution in a particular substrate processing regime. For instance, the number, size, angle of injection and/or location of the outlets within the chamber can be adapted to a particular antenna design used to inductively couple RF energy into the chamber, the gap between the upper wall and the exposed surface of the substrate, and etch process to be performed on the substrate.
FIG. 1 shows an embodiment of the invention wherein the gas injector is centrally mounted in a plasma etch reactor such as the TCP 9100™ made by LAM Research Corporation, the assignee of the present application. The etch reactor includes an antenna such as a planar coil mounted adjacent the exterior of a dielectric window and the substrate is supported on a chuck such as a cantilevered electrostatic chuck. According to the invention, instead of using a gas ring or showerhead to supply process gas into the chamber, the gas injector is mounted in an opening extending through the dielectric window. The vacuum processing chamber 10 includes a substrate holder 12 providing an electrostatic clamping force to a substrate 13 as well as an RF bias to a substrate supported thereon and a focus ring 14 for confining plasma in an area above the substrate while it is He backcooled. A source of energy for maintaining a high density (e.g. 10 11 -10 12 ions/cm 3 ) plasma in the chamber such as an antenna 18 powered by a suitable RF source and associated RF impedance matching circuitry 19 inductively couples RF energy into the chamber 10 so as to provide a high density plasma. The chamber includes suitable vacuum pumping apparatus connected to outlet 15 for maintaining the interior of the chamber at a desired pressure (e.g. below 50 mTorr, typically 1-20 mTorr). A substantially planar dielectric window 20 of uniform thickness is provided between the antenna 18 and the interior of the processing chamber 10 and forms the vacuum wall at the top of the processing chamber 10 . A gas injector 22 is provided in an opening in the window 20 and includes a plurality of gas outlets such as circular holes (not shown) for delivering process gas supplied by the gas supply 23 to the processing chamber 10 . A conical liner 30 extends from the window 20 and surrounds the substrate holder 12 .
In operation, a semiconductor substrate such as a wafer is positioned on the substrate holder 12 and is typically held in place by an electrostatic clamp, a mechanical clamp, or other clamping mechanism when He backcooling is employed. Process gas is then supplied to the vacuum processing chamber 10 by passing the process gas through the gas injector 22 . The window 20 can be planar and of uniform thickness as shown in FIG. 1 or have other configurations such as non-planar and/or non-uniform thickness geometries. A high density plasma is ignited in the space between the substrate and the window by supplying suitable RF power to the antenna 18 . After completion of etching of an individual substrate, the processed substrate is removed from the chamber and another substrate is transferred into the chamber for processing thereof.
The gas injector 22 can comprise a separate member of the same or different material as the window. For instance, the gas injector can be made of metal such as aluminum or stainless steel or dielectric materials such as quartz, alumina, silicon nitride, etc. According to a preferred embodiment, the gas injector is removably mounted in an opening in the window. However, the gas injector can also be integral with the window. For example, the gas injector can be brazed, sintered or otherwise bonded into an opening in the window or the gas injector can be machined or otherwise formed in the window, e.g. the window can be formed by sintering a ceramic powder such as Al 2 O 3 or Si 3 N 4 with the gas injector designed into the shape of the window.
FIGS. 2 a and 2 show gas distribution effects of different gas supply arrangements in an inductively coupled plasma reactor having a vacuum pump 17 connected to an outlet in the bottom of the processing chamber. In FIG. 2 a , the plasma reactor includes a gas injector in accordance with the present invention whereas the FIG. 2 arrangement includes a gas ring arrangement. In the FIG. 2 a arrangement, the gas injector is mounted in an opening in the window such that a lower end of the gas injector is flush with the inner surface of the window.
FIGS. 3 a - c show details of a gas injector design in accordance with the invention. As shown in the cross-sectional view of FIG. 3 a , the gas injector 22 includes a cylindrical body 40 having a flange 42 at an upper end thereof, a central bore 44 extending through the upper axial end, a plurality of gas outlets 46 extending between the bore and the exterior surface of the lower axial end, and O-ring grooves 48 , 50 . As shown in the perspective view of FIG. 3 b , the upper axial end of the gas injector includes a pair of flat surfaces 54 , 56 on opposite sides thereof. As shown in the axial cross-sectional view of FIG. 3 c , four gas outlets 46 open into the lower end of the bore 44 and the gas outlets 46 are spaced apart by 90°.
FIG. 4 is a graph of local SiCl x , emission from a 300 mm LAM TCP™ plasma. reactor fitted with a gas injector providing top gas injection according to the present invention compared to the same reactor fitted with a gas ring providing side gas injection. The reactor was operated at 10 mTorr reactor pressure, 800 watts power to the RF antenna, 150 watts power to the bottom electrode in the ESC, 100 sccm Cl 2 and 100 sccm Ar. As shown in the graph, the intensity of etch by-product distribution above the exposed surface of a 300 mm wafer is substantially more uniform with top gas injection.
FIG. 5 is a graph of chlorine atom distribution from a 300 mm LAM TCP™ plasma reactor fitted with a gas injector providing top gas injection according to the present invention. The reactor was operated at 10 mTorr reactor pressure, 800 watts power to the RF antenna, 150 watts power to the bottom electrode in the ESC, 100 sccm Cl 2 and 100 sccm Ar. As shown in the graph, the intensity of chlorine atom distribution above the exposed surface of the wafer is substantially uniform across a 300 mm wafer.
FIGS. 6 a - c are SEM (scanning electron microscope) images of etch profiles in polysilicon dense lines and FIGS. 6 d - f are SEM (scanning electron microscope) images of etch profiles in polysilicon isolated lines. The etch profiles are obtained from a 300 mm wafer processed in a 300 mm reactor operated at 10 mTorr and fitted with a top gas injector supplying 420 sccm total gas flow. FIG. 6 a shows the etch profile at the center of the wafer, FIG. 6 b shows the etch profile at a location intermediate the center and edge of the wafer and FIG. 6 c shows the etch profile at the edge of the wafer. Likewise, FIG. 6 d shows the etch profile at the center of the wafer, FIG. 6 e shows the etch profile at a location intermediate the center and edge of the wafer and FIG. 6 f shows the etch profile at the edge of the wafer. These SEM images show that the etch profile is substantially uniform across the 300 mm wafer.
FIGS. 7 a - d are SEM (scanning electron microscope) images of etch profiles in polysilicon across a 300 mm wafer processed in a 300 mm reactor operated at 10 mTorr reactor pressure and fitted with a top gas injector supplying 200 sccm total gas flow. FIG. 7 a shows the etch profile of dense lines at the center of the wafer and FIG. 7 b shows the etch profile of dense lines at the edge of the wafer. These SEM images show that the etch profile is substantially uniform across the 300 mm wafer. FIGS. 7 c and 7 d show etch profiles of isolated lines at the center and edge of the wafer. The delta CD (the difference between the width at the top and bottom of the line) is 68.75 nm at the center and 56.25 nm at the edge, the difference in delta CD at the center and edge being 12.5 nm or 0.0125 μm.
FIGS. 8 a - d are SEM (scanning electron microscope) images of etch profiles in polysilicon across a 300 mm wafer processed in a 300 mm reactor operated at 10 mTorr reactor pressure and fitted with side gas injection supplying 200 sccm total gas flow. FIG. 8 a shows the etch profile of dense lines at the center of the wafer and FIG. 8 b shows the etch profile of dense lines at the edge of the wafer. These SEM images show that the etch profile is not as uniform across the 300 mm wafer as in the case of top gas injection shown in FIGS. 7 a - d . FIGS. 8 c and 8 d show etch profiles of an isolated line at the center and edge of the wafer. The delta CD is 112.5 nm at the center and 62.5 nm at the edge, the difference in delta CD at the center and edge being 50 nm or 0.05 μM.
According to a preferred embodiment, the gas injector is a cylindrical member having a diameter of 1 inch and either 8 or 9 gas outlets in one end thereof. The 9 gas outlet arrangement is useful for a polysilicon etching process and the 8 gas outlet arrangement is useful for an aluminum etching process. In the 9 hole arrangement, one hole is provided in the center of the axial end of the gas injector and 8 holes are spaced 45° apart and located adjacent the outer periphery of the axial end. In the 8 hole arrangement, the center hole is omitted. In either case, the 8 holes can extend axially or they can be at an angle to the central axis of the bore extending part way through the gas injector. A preferred angle is 10 to 75°, more preferably 10 to 45° with about 30° being the most desirable angle of injection when the axial end face of the injector is flush with the inner surface of the window.
The most preferred mounting arrangement for the gas injector is a removable mounting arrangement. For instance, the gas injector could be screwed into the window or clamped to the window by a suitable clamping arrangement. A preferred removable mounting arrangement is one in which the gas injector is simply slidably fitted in the window with only one or more O-rings between the window and gas injector. For example, an O-ring can be provided in a groove around a lower part of the gas injector to provide a seal between the gas injector and the opening in the window. Another O-ring can be provided in a groove in an upper part of the gas injector to provide a seal between the gas injector and an exterior surface of the window.
The gas injector advantageously allows an operator to modify a process gas supply arrangement for a plasma etch reactor to optimize gas distribution in the reactor. For example, in plasma etching aluminum it is desirable to distribute the process gas into the plasma rather than direct the process gas directly towards the substrate being etched. In plasma etching polysilicon it is desirable to distribute the process gas into the plasma and direct the process gas directly towards the substrate being etched. Further optimization may involve selecting a gas injector which extends a desired distance below the inner surface of the window and/or includes a particular gas outlet arrangement. That is, depending on the etching process, the number of gas outlets, the location of the gas outlets such as on the axial end, as in FIG. 3 , and/or along the sides, as in FIG. 9 , of the gas injector as well as the angle(s) of injection of the gas outlets can be selected to provide optimum etching results. For example, the angle of injection is preferably larger for larger size substrates.
The gas injector can be used to plasma etch aluminum by injecting the process gas into the interior of the chamber such that the gas is not injected directly towards the substrate being processed. In a preferred embodiment, the gas injector does not include a central gas outlet in the axial end thereof. Instead, 4 or 8 gas outlets located around the periphery of the axial end are used to inject the gas at an angle of 30 to 60°, preferably 30 to 45° with respect to a direction perpendicular to the exposed surface of the substrate. As an example, the process gas can include 100 to 500 sccm of a mixture of Cl 2 and BCl 3 or Cl 2 and N 2 or BCl 3 , Cl 2 and N 2 .
The gas injector can also be used to plasma etch polysilicon by injecting the process gas into the interior of the chamber such that the gas is injected directly towards the substrate being processed. In a preferred embodiment, the gas injector includes a central gas outlet in the axial end thereof and 4 or 8 gas outlets located around the periphery of the axial end are used to inject the gas at an angle of 10 to 70°, preferably 30 to 60° with respect to a direction perpendicular to the exposed surface of the substrate. As an example, the process gas can include 100 to 500 sccm of a mixture of Cl 2 and HBr or Cl 2 only or HBr only.
In an inductively coupled plasma reactor wherein a spiral coil is used to generate plasma in the reactor, the most preferred location of the gas injector is in the center of the coil. Such a location avoids exposure of the gas injector to the toroidal zone of plasma formed by the coil. Thus, the gas outlets are located in a region of reduced electric field strength at which there is reduced plasma induced reactant decomposition. That is, there is less effect of the presence of a thin (e.g., <1 mm) plasma sheath surrounding the distal end of the gas injector which otherwise might cause electric field lines (created by the difference in potential between the plasma and grounded injector tubes) to be quite large and lead to locally enhanced deposition during etching or deposition which ultimately can clog outlets located in such regions. According to the invention, the gas injector is located beyond the enhanced electric field so as to reduce susceptibility to clogging, particularly during successive plasma processing of individual substrates such as semiconductor wafers.
In processing a semiconductor substrate, the substrate is inserted into the processing chamber 140 and clamped by a mechanical or electrostatic clamp to a substrate support. The substrate is processed in the processing chamber by energizing a process gas in the processing chamber into a high density plasma. A source of energy maintains a high density (e.g., 10 9 -10 12 ions/cm 3 , preferably 10 10 -10 12 ions/cm 3 ) plasma in the chamber. For example, an antenna 150 , such as the planar multiturn spiral coil, a non-planar multiturn coil, or an antenna having another shape, powered by a suitable RF source and suitable RF impedance matching circuitry inductively couples RF energy into the chamber to generate a high density plasma. However, the plasma can be generated by other sources such as ECR, parallel plate, helicon, helical resonator, etc., type sources. The chamber may include a suitable vacuum pumping apparatus for maintaining-the interior of the chamber at a desired pressure (e.g., below 5 Torr, preferably 1-100 mTorr). A dielectric window, such as the planar dielectric window 155 of uniform thickness or a non-planar dielectric window is provided between the antenna 150 and the interior of the processing chamber 140 and forms the vacuum wall at the top of the processing chamber 140 .
A gas supply supplying process gas into the chamber includes the gas injector described above. The process gases include reactive gasses and optional carrier gases such as Ar. Due to the small orifice size and number of gas outlets, a large pressure differential can develop between the gas injector and the chamber interior. For example, with the gas injector at a pressure of >1 Ton, and the chamber interior at a pressure of about 10 mTorr, the pressure differential is about 100:1. This results in choked, sonic flow at the gas outlets. If desired, the interior orifice of the gas outlets can be contoured to provide supersonic flow at the outlet.
Injecting the process gas at sonic velocity inhibits the plasma from penetrating the gas outlets. In the case of deposition of materials such as doped or undoped silicon dioxide, such a design prevents plasma-induced decomposition of gases such as SiH 4 and the subsequent formation of amorphous silicon residues within the gas outlets. The plasma processing system according to this embodiment provides an increased deposition rate and improved uniformity on the substrate, compared to conventional gas distribution systems, by concentrating the silicon-containing process gas above the substrate and by preferentially directing the process gas onto specific regions of the substrate.
The plasma generated by exciting the process gas is an electrically conductive gas which floats at an elevated electrical potential, i.e., the plasma potential. The plasma potential is largely determined by the capacitive coupling between the plasma and the RF-driven substrate electrode. Under typical conditions, the plasma potential can reach hundreds of volts. The gas injector generally remains at a lower potential (e.g., ground potential for a metallic injector) than the plasma. A thin sheath can form around a “plasma immersed” portion of the gas injector if the gas injector extends into the zone of plasma, in which case electric field lines created by the difference in potential between the plasma and the grounded gas injector would be perpendicular to the sheath. These electric fields can be very large as a result of bias power (applied by the substrate support) causing the plasma potential to oscillate with hundreds of volts of magnitude due to capacitive coupling with the RF powered substrate support. It is well known that external structural corners and edges, whether sharp or radiused, act to focus electric fields (See, for example, Classical Electrodynamics , by John David Jackson, John Wiley & Sons, New York, 1975, 2nd ed.). Regions with high electric fields within a plasma processor lead to enhanced gas dissociation. Thus, any tip or corner of the gas injector could lend to focus the local electric field, so that the electric field lines are concentrated around such geometric shapes and lead to enhanced local dissociation and subsequent deposition at such portions of the gas injector. Overtime, the deposition could clog the gas outlets and thus adversely affect process uniformity. According to the invention, the problem of clogging is solved by locating the gas outlets and preferably the entire gas injector outside the zone of plasma formation.
According to the invention, etch uniformity of metal such as aluminum, conductive semiconductor materials such as polysilicon and dielectric materials such as silicon dioxide including photoresist etch uniformity and selectivity to underlying materials using halogen and halocarbon based chemistries are improved. In contrast, conventional injection through a showerhead incorporated in or below a dielectric window can result in nonuniform etching across the substrate, e.g., “center fast resist etching”, which can lead to poor control of the etched features and profiles, and differences in features at the substrate center and edge. In addition, polymer formation on the TCP™ window or the showerhead can lead to undesirable particle flaking and contamination on the substrate. Other problems associated with showerhead arrangements include the additional costs associated with providing a sandwich type structure for delivering gas across the window, temperature control, the effects of gas/plasma erosion of the showerhead, ignition of plasma in the showerhead gas outlets or gap between the showerhead and the overlying window, lack of process repeatability, process drift, etc. In contrast, edge injection via a gas injection ring can result in “edge fast etching” and polymer deposition on the chamber walls. Photoresist to oxide selectivities are typically only 1-4 in these cases, where 5-10 would be desirable. The gas injector according to the invention can provide improvement in the uniformity of the resist etch rate (typically 6% 3 σ) with simultaneous resist to oxide selectivities of 5, preferably 10 or more. The present preferred injection design thus appears to provide a much more uniform flux of reactive intermediates and chemical radicals to the substrate surface, including both etch species, such as atomic chlorine and fluorine, and polymerizing species, such as CF, CF 2 , and CF 3 .
As the substrate size increases, so does the need for center fed gas. Injection systems supplying gas from gas ring arrangements cannot provide adequate process gas delivery to the center of large area substrates typically encountered in flat panel processing. This is particularly true in bottom-pumped chamber designs commonly found in plasma processing systems. In the case of plasma etching, without center gas feeding in accordance with the invention, etch by-products may stagnate above the center of the substrate in which case transport is essentially through diffusion alone. This can lead to undesirable nonuniform etching across the substrate. According to the invention, process gas is injected within the plasma region facing and in close proximity to, the center of the substrate. For instance, gas outlets of the gas injector can be located far enough below the inner surface of the window such that the gas outlets are immersed within the plasma. The gas outlets are preferably located such that there is adequate diffusion of the ions and neutral species in order to ensure a uniform etch or deposition rate. Accordingly, the gas injector can be located in a region where the azimuthal electric field induced by the TCP™ coil falls to zero, which minimises perturbations of the plasma generation zone. Furthermore, it is preferable that the gas injector is immersed a suitable distance such as no more than about 80% of the distance between the chamber ceiling and the substrate. This ensures that the ion diffusion from upper regions of the chamber have sufficient space to fill in the lower ion density immediately beneath the gas injector. This will minimize any “shadow” of the gas injector in the ion flux to the substrate.
Using the immersed gas injector allows for independent selection of the center gas feed location and the chamber aspect ratio. This facilitates efficient utilization of process gas and improves process gas delivery to the central region of large area substrates with minimal disturbance to plasma uniformity. This configuration is also advantageous because locating the gas outlets close to the substrate increases the convective transport relative to diffusive transport in the region immediately above the substrate. In addition to improving the delivery of the reactants, the gas injector facilitates efficient transport of etch by-products out of the substrate region, which can favorably impact etch uniformity and profile control, particularly in chemically driven applications such as aluminum etching.
According to an exemplary embodiment, the injection orifices are small enough that any plasma sheath formed around the gas injector is largely unaffected by the presence of the gas outlets. The total area of the gas outlets can be less than, greater than or the same as the cross-sectional area of the bore in the gas injector. The total area of the gas outlets preferably ensures that process gas be delivered from each gas outlet so as to be distributed evenly within the chamber. The injection to various regions above the substrate can be tailored by utilizing the same or different diameters for the various gas outlets.
The gas outlets can have any desired shape such as uniform diameter along the entire length thereof or other shape such as conically tapered, flared surfaces or radially contoured surfaces. The gas outlets can be oriented to inject the gas in any direction, including directly at the substrate, at an acute angle with respect to the substrate, parallel to the substrate or back toward the upper plasma boundary surface (at an oblique angle with respect to the longitudinal axis of the nozzle), or combinations thereof. It is desired to achieve a uniform flux of chemical radicals and reactive intermediate species onto the substrate surface to facilitate uniform etch and deposition rates across the large area substrate. If desired, additional gas injection arrangements can also be provided near the periphery of the substrate or from other chamber walls.
Preferably, no sharp corners exist at the distal end of the gas injector in order to reduce local electric field enhancement near the tip. However, there may be cases where such field enhancement can be advantageous.
The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.
|
A plasma processing system for plasma processing of substrates such as semiconductor wafers. The system includes a plasma processing chamber, a substrate support for supporting a substrate within the processing chamber, a dielectric member having an interior surface facing the substrate support, the dielectric member forming a wall of the processing chamber, a gas injector fixed to, part of or removably mounted in an opening in the dielectric window, the gas injector including a plurality of gas outlets supplying process gas into the chamber, and an RF energy source such as a planar or non-planar spiral coil which inductively couples RF energy through the dielectric member and into the chamber to energize the process gas into a plasma state. The arrangement permits modification of gas delivery arrangements to meet the needs of a particular processing regime. In addition, compared to consumable showerhead arrangements, the use of a removably mounted gas injector can be replaced more easily and economically.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of data analysis, and more specifically to identifying and/or compensating for influencers that can have an impact on a statistical outcome.
2. Background
Databases are often created as a by-product of normal operations such as health care, retail sales, and loan processing, and it is often possible to extract highly useful information by properly analyzing these databases. For example, medical researchers may obtain valuable insights into disease progression, adverse side effects of medications, or typical patient characteristics from hospital databases; buyers can identify important purchasing patterns from inventory or point-of-sale data; and bank analysts can develop fair and accurate criteria for screening loan applicants by examining the payment histories of previous borrowers.
Conventional techniques for analyzing such databases, however, are susceptible to errors that may be introduced by “confounders.” Confounders are factors whose significance has been overlooked by the data analyst, but nevertheless influence the outcome of interest. An excellent example of a confounder's impact on an outcome can be found in the following data, taken from “The Effectiveness of Adjustment by Subclassification in Removing Bias in Observational Studies for Causal Effects” by W. G. Cochran, Biometrics, v. 24, pp. 295–313 (1968).
Non-
Cigarette
Smoking status
smoker
smoker
Mortality rates
20.2
20.5
per 1000 person-years
Taking this data at face value could lead one to the incorrect conclusion that cigarette smoking is not harmful. A more in-depth analysis reveals, however, that the above results were confounded by age—it turns out that the nonsmokers represented in the database were significantly older than the cigarette smokers, with average ages of 54.9 years and 50.5 years, respectively. When the above mortality rates are adjusted for age, the results are as follows:
Non-
Cigarette
Smoking status
smoker
smoker
Age-adjusted mortality rates
20.2
29.5
per 1000 person-years
Analysts with an in-depth understanding of a particular subject matter may be able to recognize the impact of a confounder, and eventually track down the source of error. But analysts who do not recognize the presence of a confounder may reach an incorrect conclusion.
One prior art approach for avoiding the effects of confounders is to carefully design an experiment or scientific trial using a control group. A particular factor (e.g., receiving a particular drug) is then randomly varied among the participants, and the results are observed. This approach is commonly used in medical and scientific research to verify a hypothesis. Unfortunately, this approach is very expensive to implement, because it requires performing new experiments and data analysis to test each and every hypothesis, or risking that a flawed hypothesis will be accepted and perhaps acted on.
Another prior art approach for avoiding the effects of confounders is by using preexisting data (e.g., from an existing database), and obtaining the participation of an expert in the relevant domain (e.g., a medical doctor) and a statistician to compensate for confounders for each hypothesis proposed by a data analyst. This approach can provide high quality results, but makes inefficient use of the domain expert's time and the statistician's time, who may be asked similar questions by multiple data analysts. And due to the heavy involvement of the domain expert and statistician, this prior art approach is also expensive to implement.
The inventors have recognized the need to improve the existing situation, and to enable researchers to form and verify their hypotheses more easily, without relying so heavily on freshly obtained experimental data to verify each hypothesis, and without relying on close cooperation with domain experts and statisticians.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a method of identifying relationships between influencers and outcomes under a particular set of conditions. In this method, a model of information that characterizes relationships under many different conditions between influencers and outcomes is built. A query that specifies a set of conditions is inputted, and a relationship between the set of conditions specified in the query and a particular outcome that is represented in the model is determined. Based on the model, at least one potential influencer of the particular outcome is identified.
Another aspect of the invention relates to a method of identifying relationships between influencers and outcomes under a particular set of conditions. In this method, a model of information that characterizes relationships under many different conditions between influencers and outcomes is built. A query that specifies a set of conditions is inputted, and a relationship between the set of conditions specified in the query and a particular influencer that is represented in the model is determined. A relationship between the query and a particular outcome that is represented in the model is also determined. Based on the model, at least one potential influencer of the particular outcome is identified. This potential influencer is unaccounted for by the query.
Another aspect of the invention relates to a method of identifying relationships between influencers and outcomes under a particular set of conditions. In this method, a model of information that characterizes relationships under many different conditions between a plurality of nodes is built. In this model, at least some of the nodes represent influencers and at least some of the nodes represent outcomes. A query that relates to at least one of the nodes is inputted, and a relationship is determined between the query and the nodes of the model. Based on the model, a potential influencer of an outcome associated with the query is identified.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of a preferred embodiment of the present invention.
FIG. 2A is a pictorial representation of a first metadata model depicting relationships between influencers and outcomes.
FIG. 2B is a pictorial representation of a second metadata model depicting relationships between influencers and outcomes.
FIG. 3 is flowchart of a method for identifying potential confounders and reporting those confounders to a user.
FIG. 4 is flowchart of a method for identifying potential confounders and adjusting for the impact of those confounders.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a functional block diagram of a preferred embodiment of the present invention. The illustrated functions are preferably implemented using conventional computer hardware and peripherals. A user 10 provides inputs to the system via input interface 12 , and receives outputs from the system via output interface 11 . A query processor 13 accepts the user's input from the input interface 12 . The input interface 12 may be implemented using any of a variety of conventional techniques, such as graphical, command-line, or natural language interfaces. Inputted queries are submitted to the query processor 13 , which parses each query and submits the parsed query to the confounder compensation/identification process 14 (hereinafter “CCIP”). Parsed queries may be represented in a variety of ways, such as SQL select statements or natural language expressions. The CCIP 14 accepts the parsed query, implements a process to determine a result, and sends the result to the user 10 via the output interface 11 . The result may be presented using any suitable user interface technique, such as text, tabular or graphical displays, or combinations thereof.
Examples of the processes implemented in the CCIP 14 are described below. Preferably, the CCIP 14 has access to metadata 15 and to a raw data database 18 . The metadata 15 and the raw data database 18 may be, for example, relational database systems, computer file systems, or other systems that are capable of maintaining the required data.
Compensation for confounders relies heavily on metadata 15 . The metadata 15 may be generated by human experts in a particular field of study (aided by statisticians when necessary), by a computerized process that recognizes relationships within a body of raw data (using, for example, statistical techniques or artificial intelligence methods), or by a combination of human and computerized processes.
Preferably, the metadata 15 specifies whether a relationship exists between a plurality of influencers and outcomes. Optionally, the metadata 15 may also describe a characteristic of that relationship. The metadata 15 is preferably established so as to encode both expert domain information and statistical opinion information. Because this information is encoded into the metadata 15 , it can be subsequently extracted from the metadata 15 by an automated process (including, e.g., the processes described below). The metadata 15 can serve as a repository for the experts' knowledge concerning the various influencers and outcomes. Consulting this repository enables data analysts to obtain the benefit of this knowledge without actually consulting a live expert.
Once the metadata 15 has been established, it is stored in a suitable media (e.g., RAM, hard disks, etc.) for access by the processes described below. The mechanics of storing and accessing the metadata 15 may be implemented in any conventional manner, using any of a variety of conventional database programs running on conventional computer hardware (not shown).
FIG. 2A is an example (in the context of the health field) of a directed graph of relationships that may be used as the metadata 15 in the processes described herein. In the illustrated directed graph, nodes represent influencers and outcomes, and directed edges represent relationships. Although other representations are feasible, a directed graph representation is convenient for visual presentation during the development of the metadata model by domain and statistical experts because it assists visualization of the relationships that exist between the various influencers and outcomes. It can also be easily translated into a format that can be accessed by the CCIP 14 (shown in FIG. 1 ).
In the example shown in FIG. 2A , nodes 20 – 26 appear on the left side of the figure, and nodes 27 – 29 appears on the right side of the page. When a causal relationship exists between two nodes, a directed edge is shown as an arrow from the influencer to the outcome. When no such relationship exists between two nodes, no directed edge is shown between those nodes. In the illustrated example, nodes 20 – 26 are all influencers of one or more of the nodes 27 – 29 (for example, smoking status 23 increases the probability of lung cancer 27 ). Nodes 23 , 24 , and 25 are also outcomes, because they are affected by the state of the nodes 27 and 29 (e.g., lung cancer status 27 may cause a person to quit smoking, and move to a zip code with cleaner air). Nodes 27 and 29 are both influencers and outcomes, and node 28 is an outcome only. Of course, in the context of health, the relationships illustrated in FIG. 2A represent only a small subset selected from the potential universe of entries that could impact the various illustrated outcomes. Preferably, all factors known to have a significant impact on each of the outcomes should be included in the metadata 15 .
FIG. 2B is another example of a directed graph of relationships that that may be used as the metadata 15 in the processes described herein. FIG. 2B is similar to FIG. 2A , except that additional information about the strength of each relationship is included. In FIG. 2B , strong relationships are indicated by solid lines, medium relationships by dashed lines, and weak relationships by dotted lines.
FIG. 3 illustrates a “diagnostic” mode of operation, where the metadata is used to identify potential confounders and to report those confounders to the user. In step 32 , the metadata model is formed to define a set of relationships between the influencers and the outcomes. Examples of forming the metadata model are described above in connection with FIGS. 2A and 2B . This step is preferably implemented before the remaining steps (e.g., days or even months in advance).
In step 33 , the system accepts a query from the user (via the input interface 12 , shown in FIG. 1 ), and the influencers, outcomes, and relationships contained in that query are captured by the system. Queries from the user may take any number of forms. Some forms will identify only an influencer (e.g., “what are the bad effects of smoking?”) or only an outcome (e.g., “tell me the factors that influence lung cancer status”). Other queries may include both influencers and outcomes (e.g., “is there a relationship between rate of death and a subject's zip code?”). Still other queries may include the nature of the relationship between the influencers and the outcomes in an imprecise manner, either implicitly (e.g., “show me rates of death for smokers and non-smokers”) or explicitly (e.g., “does smoking increase the risk of lung cancer?”). Other queries may include the nature of the relationship between the influencers and the outcomes in a more precise manner (e.g., does smoking two packs of low-tar cigarettes a day increase the risk of lung cancer by a factor of four?”). In some cases, a query may involve more than one influencer or outcome (e.g., “what is the death rate of diabetics that also have skin cancer, as compared to the general population?”).
Queries may be accepted in step 33 in any desired format, including, for example, statements, questions, and lists of terms, as long as the query processor 13 (shown in FIG. 1 ) is programmed to handle the desired input format. Any suitable input interface 12 (shown in FIG. 1 ) may be used for inputting the query. One example is to provide a set of text-input fields on a computer-generated display, and to display an appropriate message (e.g., “to investigate the relationship between an influencer and an outcome, type one or more influencers in field A, an outcome in field B, then click “go”). Another example of a suitable user interface would be to select an influencer, an outcome, and a relationship from drop-down menus that are populated based on the contents of the metadata 15 . Similar arrangements can be readily envisioned for various different query types, including those described above. Queries may also be accepted from the user in plain English (or any other language) using natural-language recognition software. In this case, a user would be able to type (or speak) a complete statement of their query using any conventional user interface. Alternative user interfaces can be readily envisioned.
The end result of the query accepting step is a set of influencers, outcomes, and relationships. Depending on the particular query that was inputted by the user, this set may contain only influencers, only outcomes, or both influencers and outcomes. If relationships were also inputted by the user, these relationships would also be included in the set.
In step 34 , the terminology that was used in the inputted query is analyzed to determine which entries in the metadata are implicated by the query. In cases when the query uses the exact same terminology as the metadata, this step may be implemented by looking up the query terms in a table that contains all the metadata terms. When the identical terminology is not used, the query terminology must be analyzed to map the query terms onto the metadata terms before subsequent processing can occur. For example, if the metadata contains a relationship indicating links skin cancer and death, but the query used the terminology “how long do people with melanomas usually live?” The query term “melanoma” must be associated with “skin cancer” in the metadata, and the query terms “how long” and “live” must be associated with “death” in the metadata. This correspondence may be implemented, for example, using a thesaurus. More sophisticated language-recognition algorithms may also be used. In certain cases, an appropriate computation may be required to match the query terminology with the metadata. For example, if the metadata includes “age,” but the query relates to date of birth, subtraction would be appropriate. Similar conversions may also be required when the raw data is accessed. The end result of this step is the set of metadata concepts that were recognized in the query, referred to hereinafter as “recognized concepts.”
In step 35 the metadata is analyzed, preferably for each of the recognized concepts, to determine which things in the metadata influence the recognized concepts, and/or which things in the metadata are influenced by the recognized concepts. In the examples of FIGS. 2A and 2B , this may be accomplished by noting which nodes are linked to each of the recognized concepts by a directed edge. Any node in the metadata that has an influence on one of the recognized concepts (and has not already been accounted for in the query) is identified as a potential confounder. For example, if a query asks for the relationship between outdoor leisure and skin cancer for a particular age group, examination of the FIG. 2A metadata model would reveal that zip code and heredity are potential confounders of the “skin cancer” outcome. Optionally, when the strength of the relationships are encoded in the metadata (as shown in FIG. 2B ), the user may be provided with an option to set a threshold that would exclude relationships classified as “weak” or “medium” from being identified.
In step 36 , the impact of each of the identified potential confounders on the query is analyzed to determine whether, under the circumstances presented by the query, the potential confounder is likely to have an impact on the outcome. This step is preferably implemented by having the CCIP 14 access the raw data database 18 (both shown in FIG. 1 ) to determine whether the confounder is implicated by the subpopulation delineation called for by the query. The database may be accessed using conventional database accessing techniques such as SQL queries in conjunction with conventional statistical techniques.
The concept of subpopulation delineation can be understood in the context of the following example, where the query is “do females have a higher incidence of skin cancer than males”? In this example, age would be identified as a potential confounder for the outcome of “skin cancer” based on the metadata. Based on the query, the universe is divided into two subpopulations—males and females. If the age distribution in these two subpopulations is different, age is likely to have an impact on the outcome, and is accepted as a probable confounder. But if the age distribution in the two subpopulations is similar, then age is unlikely to have an impact on the outcome, and would not be a probable confounder (despite the fact that the metadata indicates a causal relationship may exist between smoking and death).
Note that step 36 is optional, and may be omitted. In this case, the potential confounders would be reported below in step 37 (instead of the probable confounders).
In step 37 , a response to the original query is reported to the user. Preferably, this response is based on an analysis of the raw data 18 by the CCIP 14 data (both shown in FIG. 1 ), and is responsive to the presented query. For example, for the query “how do the mortality rates for smokers and nonsmokers compare?”, the reported result could be something like “the mortality for smokers and nonsmokers are as follows . . . ”. In addition to the response to the original query, any probable confounders that were identified in step 36 are reported to the user (or, if step 36 was omitted, the potential confounders). For example, in cases where age impacts the mortality rate, a suitable message (e.g., “WARNING: you did not indicate an age range for the subjects, which would have a significant impact on the reported results”) would be presented to the user. Both the response to the query and the reporting of confounders are preferably presented to the user via output interface 11 (shown in FIG. 1 ) using any user interface technique appropriate for the data being displayed (e.g., pop-up display windows paragraphs of text, tabular displays, graphic displays, etc.).
Optionally, an additional level of detail may be provided when reporting a confounder. For example, if the inputted query was “show me the mortality rates for smokers and non-smokers,” and step 36 identified age as a probable confounder, the system could generate a message such as “WARNING: the results provided above do not account for age—the average age of the smokers in the examined database is 45, but the average age of non-smokers is 57.” The user could subsequently use this information to refine their query.
FIG. 4 illustrates a “statistical-analytic” mode of operation, where the metadata is used to actually adjust or correct a query. Steps 42 – 46 of this embodiment are similar to steps 32 – 36 of the embodiment described above in connection with FIG. 3 .
After steps 42 – 46 have been implemented (i.e., after all the probable confounders have been identified), processing proceeds to step 48 where, the actual impact of the probable confounders on the query is computed for the particular situation in question. This step is preferably implemented by having the CCIP 14 access the raw data database 18 (both shown in FIG. 1 ), using conventional database accessing techniques such as SQL queries in conjunction with conventional statistical techniques. For example, if the inputted query was “show me the mortality rates for smokers and non-smokers,” and age was identified as an probable confounder in step 46 , the CCIP 14 could interrogate the database using appropriate SQL queries for the age group in question to determine the actual impact of heredity on skin cancer. If the impact is sufficiently large, the probable confounder “heredity” would be recognized as an actual confounder under the particular set of circumstances delineated by the query.
Statistical techniques for determining the effects of probable confounders may be chosen on the basis of many factors, including computational and statistical resources available in the query processor 13 , the CCIP 14 , types of entities (e.g., continuous vs. discrete), relationships between a confounder and outcome, and the ability of an end user to understand the technique and its output. For many queries, the appropriate analysis involves comparing the distribution of probable confounders in two groups, such as “smokers” vs. “non-smokers.” For individual confounders, applicable techniques may include descriptive statistics, graphical summaries, or Student's t statistic comparing the means for each group. It may be necessary to consider groups of confounders, in which case multi-way analyses of variance may be appropriate. Propensity scores may also be used to analyze the relevant data, either alone or in conjunction with other statistical analysis techniques.
One example of the application of statistical techniques to the database analysis is age-normalization. For example, to determine whether smoking contributes to mortality for a particular subpopulation, the system can divide the subpopulation into a number of age groups (e.g., into five age groups), and compute the mortality rates for both the smokers and nonsmokers in each age group. The average of the five smoking numbers are then compared to the average of the five non-smoking numbers, and an age-adjusted mortality rate is determined. If the age-adjusted mortality rate differs from the non-adjusted mortality rate, this would indicate that age is an actual confounder for the particular circumstance presented by the query.
Once the actual impact of the confounder has been determined, the query is adjusted accordingly. For example, if the inputted query was “show me the mortality rates for smokers and non-smokers,” and age was identified as an probable confounder in step 46 , the system would first determine the impact of the confounder on the query (i.e., the impact of age), and then adjust the query to take the confounder into account. In this example, the query adjustment can be implemented by changing “mortality rate” to “age-adjusted mortality rate.” The specifics of adjusting the query to compensate for the confounders will depend on the form of the query, and may be implemented, for example, using a suitable language processor.
Once the appropriate adjustment to the query has been determined, processing proceeds to step 49 where the adjusted query is presented to the user together with the results for the adjusted query (via the output interface 11 shown in FIG. 1 ). In the current example, one appropriate presentation would be “the AGE-ADJUSTED mortality rates for smokers and non-smokers are as follows . . . ”. Preferably, any modifications that were made to the query are flagged to the user in a suitable manner (e.g., by highlighting them, using italics, or generating up a suitable explanatory message in a pop-up window).
The above-described embodiments can advantageously be used to either flag probable confounders, so that a data explorers can re-formulate their hypothesis, or to compensate for the effects of the confounders. It can also be used to reduce reliance on the expensive and time consuming process of obtaining fresh experimental data to validate each hypothesis, thereby making the data-explorer's efforts more productive. It can also help amortize the cost of domain and statistical knowledge across many data-explorers working in the same general field, because the metadata and processing steps allow reuse of the domain and statistical knowledge numerous times once it has been captured.
It should be noted that while the above-described embodiments have been explained in the context of health care, they are equally applicable in other fields, including, but not limited to, finance, retail sales, agriculture, etc. Moreover, while the present invention has been explained in the context of the preferred embodiments described above, it is to be understood that various changes may be made to those embodiments, and various equivalents may be substituted, without departing from the spirit or scope of the invention, as will be apparent to persons skilled in the relevant arts.
|
Systems and methods are disclosed for identifying and/or compensating for relationships between influencers and outcomes. First, a metadata model of information that characterizes relationships between influencers and outcomes is built. A query is accepted from a user, and an outcome of interest is determined based on the query. The model is subsequently relied on to flag influencers that might have an impact on an outcome of interest. The impact of these influencers on the outcome of interest is then analyzed with respect to specific conditions. When the impact is sufficiently large, the user is notified or an adjustment is made to the user's query.
| 8
|
CROSS-REFERENCE TO RELATED PROVISIONAL APPLICATION
The present application claims priority to U.S. Provisional Application 60/565,119, filed on Apr. 23, 2004, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates generally to material off-loading devices, and more specifically to spouts for off-loading harvested materials from agricultural harvesting equipment.
BACKGROUND
Agricultural harvesting equipment often includes some form of on-board grain or other harvested material storage. Typically, this on-board storage is only for temporary storage of material and needs to be periodically unloaded during a day's harvesting operation. In order to keep production efficiency as high as possible, this off-loading of material may be accomplished in the field without stopping the operation of the harvester. A truck or farm wagon (a discharge vehicle) may be pulled alongside the harvester to receive the material and the harvester may be equipped with a flexible spout that can be positioned above the discharge vehicle. Material can then be discharged from the on-board storage through the spout by an auger or similar device and into the discharge vehicle, while the harvester continues to collect additional material.
Loss of off-loaded material may occur when the spout is positioned too high above the discharge vehicle. Wind may blow material from the discharge stream and out of the discharge vehicle onto the ground. Also, vertical separation between the spout and the discharge vehicle may cause operator error in the alignment of the spout and the discharge vehicle. Discharge vehicles may vary in height, and the height of a discharge spout above the ground may vary between different models and brands of harvesters. It is desirable to provide improvements to the discharge spout to accommodate different height of vehicles and harvesters.
SUMMARY
The present invention relates to an extendable/retractable spout for use with an agricultural harvester. The spout permits the position of a lower end of the spout to be adjusted in height to match the height of a truck or wagon into which grain is being transferred. The present invention further relates to a harvester including an extendable/retractable spout that can be actuated remotely by an operator.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate several aspects of the present invention and together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows:
FIG. 1 is a perspective view of a prior art combine harvester.
FIG. 2 is a perspective view of a prior art harvester discharging grain into a farm wagon.
FIG. 3 is a perspective view of a grain discharge mechanism with an extendable spout according to the present invention.
FIG. 4 is a perspective view of the extendable spout of FIG. 3 , with the spout fully extended.
FIG. 5 is a perspective view of the extendable spout of FIG. 4 , with the spout fully retracted.
FIG. 6 is a side view of a distal end of the discharge mechanism of FIG. 3 , with an interface for the extendable spout according to the present invention.
FIG. 7 is a side view of the distal end of the discharge mechanism and interface of FIG. 6 , with a drive mechanism mount positioned above the interface.
FIG. 8 is a perspective view of the drive mechanism mount of FIG. 7 .
FIG. 9 is a closer view of the distal end of the discharge mechanism and the extendable spout of FIG. 3 , with an alternative tube mounting arrangement.
FIG. 10 is a perspective view of the drive mechanism of FIG. 9 .
FIG. 11 is a perspective view of a portion of the extendable spout of FIGS. 3 and 4 .
FIG. 12 is a side view of a pair of tubes for mounting to the side of the extendable spout of FIGS. 3 and 4 .
FIG. 13 is a closer perspective view of the tubes of FIG. 12 mounted to the side of the portion of the extendable spout of FIG. 11 .
DETAILED DESCRIPTION
Reference will now be made in detail to the exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 1 shows a prior art agricultural harvester 10 with a movable discharge auger 12 having a fixed spout 14 . Auger 12 can be moved sideways through an arc about a pivot point defined on an upper portion of harvester body 16 . Within harvester body 16 is a temporary on-board grain storage bin for holding grain or other harvested material collected by harvester 10 . An operator's position or cab 18 is located remotely from either auger 12 or spout 14 .
FIG. 2 is a view sideways from cab 18 of harvester 10 , with auger 12 positioned so that spout 14 is above a farm wagon 20 . Grain 22 is being discharged from harvester 10 into wagon 20 . A lower end of spout 14 is located a distance h above wagon 20 . This distance h may allow grain 22 falling from spout 14 to be scattered by wind and end up on the ground instead of in wagon 20 . As can be seen in FIG. 2 , auger 12 may be swung forward enough so that spout 14 is generally even with cab 18 , permitting an operator to see where spout 14 is located with respect to wagon 20 . However, distance h may create an optical illusion for the operator, and cause the operator to misalign spout 14 . Such misalignment may cause grain 22 to be discharged onto the ground.
Referring now to FIG. 3 , auger 12 extends as part of a discharge mechanism 28 which has an end 30 within the on-board grain storage bin of harvester 10 . At a distal or discharge end 24 of auger 12 is mounted an extendable and retractable spout 26 , which extends downward in place of spout 14 . As shown in FIG. 3 , extendable spout 26 is at a point of greatest extension, meaning that a lower end 32 of spout 26 is at a point closest to the ground. This lowering of end 32 permits an operator to reduce or eliminate the distance h that grain 22 must drop before entering within wagon 22 or a truck or similar grain transport.
Referring now to FIG. 4 , retractable spout 24 includes a drive mechanism 36 and a drive mechanism mount 34 mounted above distal end 24 of auger 12 . An interface 38 provides a transition for grain 22 to exit distal end 24 and enter an upper end 40 of a top most or upper nesting cone 42 . Spout 24 includes a bottom most or lower nesting cone 44 and one or more intermediate nesting cones 46 . Alongside cones 42 , 44 and 46 are telescoping tubes 48 . Tubes 48 are hollow and vary in diameter with a largest diameter tube 48 mounted adjacent cone 42 , and decreasing in diameter to the smallest diameter tube 48 mounted adjacent cone 44 . The higher mounted tubes 48 have a large enough inner diameter for the next lowest tube 48 to telescope within. As seen in FIG. 5 , spout 24 is shown in retracted position with cones 42 , 44 and 46 nesting within each other and tubes 48 telescoped within each other. An upper hollow tube mount 50 connects tubes 48 to mount 34 and has a large enough inner diameter to permit the largest tube 48 to telescope within. Note that in the extended position shown in FIG. 4 , the cones remain overlapped with each other to provide a generally continuous grain passage from auger 12 to lower end 32 .
Referring now to FIG. 6 , interface 38 includes an upper portion 56 configured to fit closely about auger 12 adjacent distal end 24 . While not needed to seal against auger 12 , a close fit is desirable to reduce grain loss or blow by during discharge. Below upper portion 56 is a tapered portion 54 leading to a lower grain exit 52 through which grain 22 flows to enter upper cone 42 . The size of upper portion 56 may be determined based on the size of auger 12 and distal end 24 and whatever opening is formed for grain at distal end 24 . Tapered portion 54 and grain exit 52 should be sized to provide adequate flow rates based on the expected maximum grain volume and characteristics. Any significant constriction of grain flow caused by tapered portion 54 may materially add to the weight of grain within auger 12 and cause back ups within auger 12 which may damage equipment or grain.
FIG. 7 shows mount 34 positioned above distal end 24 of auger 12 and also positioned above interface 38 . It may be desirable to have common fasteners such as fasteners 58 mounting both mount 34 and interface 38 to auger 12 , although this is not required. Referring now to also to FIG. 8 , a pair of tube mounting wings 60 may extend from sides 64 of mount 38 and provide openings 68 through which an upper end of tube mounts 50 extend. An upper mounting plate 62 provides a mounting surface for drive mechanism 36 . A u-shaped opening 66 is defined between sides 64 and upper mounting plate 62 for receiving auger 12 and distal end 24 .
As shown in FIG. 9 , an alternative mounting arrangement for tubes 50 may be included in mount 34 . In place of wings 60 , a pin or bar 74 may extend through sides 64 and engage openings in an upper portion of tube mounts 50 . Also shown in FIG. 9 are drive mechanism 36 mounted to upper plate 62 . Drive mechanism 36 includes a drum 70 and may also include a motor 72 mounted directly adjacent rum 70 . Cables 76 are attached to drum 70 and extend into tubes 50 and down tubes 48 to lower cone 44 , where they are attached. Drum 70 rotates to take up cable 76 and draw cones 42 , 44 and 46 into the retracted position shown in FIG. 4 . Motor 72 , as shown, is an electric motor coupled directly or through a geared transmission to drum 70 . Alternatively, a pneumatically driven motor may be used in place of electric motor 72 , or other means of rotating drum 70 may be substituted. It is desirable that any weight mounted adjacent distal end 24 of auger 12 be kept to a minimum and that the risk of contamination of grain also be minimized.
FIG. 10 shows drive mechanism 34 removed from mount 36 . A coupling 78 is positioned between and connects drum 70 to motor 72 . Drum 70 includes a pair of grooves 80 within which cables 76 may be attached. As cables 76 are rolled onto drum 70 to retract cones 42 , 44 and 46 , each cable 76 is kept separate from the other cable 76 within one of the grooves. A drum frame 86 is positioned about drum 70 .
Mounted on top of drum frame 86 are an electronic motor control or actuator 82 and a pair of limits stop switches 84 . Switches 84 cooperate with a position indicator 88 mounted to a threaded shaft coupled to drum 70 . As drum 70 rotates to extend or retract cables 76 , indicator 88 moves laterally along shaft 90 . When indicator 88 contacts either limit stop 84 , power to motor 72 is cut off by electronic controller or actuator 82 . While this limit indication and control arrangement is configured for use of an electric motor 72 , other similar arrangements may be configured to control alternative drive systems. Some form of limit stop arrangement is desirable as spout 24 is remotely actuated from cab 18 . Since the operator will preferably be positioned remotely from distal end 24 of auger 12 , the operator will not be able to closely monitor operation and position of spout 24 . With the limit stop arrangement shown (or an equivalent system), the operator will need only initiate movement of motor 72 and movement will be ended when spout 24 is either fully extended or retracted.
Referring now to FIG. 11 , cones 42 , 44 and 46 are preferably identically configured and include an upper wider end and a lower narrower end. Extending from an outer wall of a body 106 on either side are a pair of tube flange mounts 104 . Each of the tubes 48 and 50 include flanges for engaging flange mounts 104 and coupling the tubes to the cones. Upper end 100 and lower end 102 are preferably sized and configured so that one cone may nest within another cone without binding. Preferably, a gap or space will be provided between an inner wall of one cone's body 106 and an outer wall of the other cone's body 106 when the cones are fully nested, as shown in FIG. 4 . This will permit stray material such as grain or harvest waste to be tolerated without impairing operation (extension and retraction) of spout 24 .
In FIG. 12 , tubes 48 and 50 both include longitudinally extending slots 112 . Tube 50 includes a mounting flange 110 adjacent an upper end for engaging tube mount wings 60 . Alternatively, an opening could be provided for pin 74 to extend through. Adjacent a lower end of both tube 50 and tube 48 is a mounting flange 108 configured to engage tube flange mounts 104 of cones 42 , 44 and 46 , as shown in FIG. 13 .
Referring now to FIG. 13 , extending radially adjacent a top end of each tube 48 is a stop pin 114 . Each of the slots 112 in tubes 48 and 50 includes a closed lower end 116 . As cable 76 is extended from drum 70 , cones 42 , 44 and 46 are allowed to extend toward the extended position shown in FIG. 3 . Pins 114 ride within slots 112 and closed ends 116 prevent the nesting cones from extending top far below the next adjacent upper cone and disengaging from spout 24 . Openings 118 are provided in tube flange mounts 104 so that engagement of tubes 48 and 50 with cones 42 , 44 and 46 may be secured. Any fasteners extended through openings 118 will preferably be removable fasteners such as screws or bolts, so that spout 24 can be disassembled and reassembled for after-market installation, cleaning, repair or maintenance. Similarly, pin 112 is ideally removably mounted within tubes 48 so that the telescoping tubes may be disassembled and reassembled for after-market installation, cleaning, repair or maintenance.
The above specification, examples and data provide a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
|
An adjustable height spout for an agricultural harvester may be remotely actuated by an operator. The spout may be positioned to match a height of a receptacle into which grain from the harvester is being transferred. An agricultural harvester including an adjustable height spout which may be actuated remotely by an operator.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2008-0133808 filed in the Korean Intellectual Property Office on Dec. 24, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a secondary battery, and more particularly, to a secondary battery having a current interrupt device (CID) between the bottom of a case and a negative current collecting plate.
[0004] 2. Description of the Related Art
[0005] As generally known, a secondary battery can be recharged and discharged, unlike a primary battery. Secondary batteries may be classified into low-capacity batteries and high-capacity batteries.
[0006] For example, a low-capacity secondary battery includes unit batteries, and is mainly used for small portable electronic devices, such as cellular phones, laptop computers, and camcorders, whereas high-capacity batteries are used as the power supply for driving motors in hybrid electric vehicles and the like. A high-capacity secondary battery forms a battery module by connecting a plurality of unit batteries in the form of a pack, and is used as the power supply for driving motors in hybrid electric vehicles and the like.
[0007] Each of the unit batteries includes an electrode assembly including a positive electrode, a separator, and a negative electrode, a case for accommodating the electrode assembly, and a cap assembly coupled with the case to seal the case and having an electrode terminal electrically connected with the electrode assembly.
[0008] For example, in a cylindrical secondary battery, the positive and negative electrodes in the electrode assembly respectively include non-coating portions on which an active material is not coated, and the positive electrode non-coating portion and the negative electrode non-coating portion are positioned at opposite sides to each other.
[0009] A negative current collecting plate is attached to the negative electrode non-coating portion, and a positive current collecting plate is attached to the positive electrode non-coating portion. The negative current collecting plate is connected to the case and the positive current collecting plate is connected to the cap assembly to thus draw current to the outside.
[0010] When the negative current collecting plate is connected to the case, the case serves as a negative electrode terminal. When the positive current collecting plate is connected to the cap assembly, the cap assembly serves as a positive electrode terminal. The cap assembly and the case are coupled with each other in an insulation structure through a gasket.
[0011] The cap assembly includes a cap plate, a positive temperature device, a vent plate, an insulator, a middle plate, a sub-plate, and a connecting member that are sequentially provided from the outside. The connecting member electrically connects the positive current collecting plate and the middle plate. The vent plate and the sub-plate are connected to each other by welding, with the insulator and the middle plate interposed therebetween.
[0012] The vent plate forms a vent which is to be connected to the sub-plate, the vent and the sub-plate form a connection portion, and as the connection portion is formed by welding, they are easily broken and disconnected when the internal pressure of the battery rises, to thus cut off current. That is, the current interrupt device (CID) is formed between the vent plate and sub-plate of the cap assembly.
[0013] To this end, the vent plate is provided with notches so that the circumference of the vent has a smaller thickness than other portions of the vent plate have. However, such a cap assembly interrupts current while the vent is separated as the notches are ruptured by explosion in the event of an increase of the internal pressure of the battery.
[0014] In this manner, the current interrupt device cuts off current after explosion, so that the current interrupt device is not able to properly prevent the explosion of the battery. Moreover, the sub-plate forming the connection portion together with the vent is formed in a plate shape, and hence there is a large dispersion of an operating pressure, i.e., separation pressure, at which the connection portion of the sub-plate and the vent is disconnected.
[0015] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0016] The embodiments of the present invention provide a secondary battery which can effectively serve to prevent explosion since current is interrupted by the disconnection of a connection portion before explosion.
[0017] The embodiments of the present invention provide a secondary battery which can reduce the dispersion of the operating pressure of a disconnection portion since the connection portion can be designed so as to be disconnected under a predetermined operating pressure.
[0018] The embodiments of the present invention provide a secondary battery which improves reliability with respect to current interruption because a disconnected state of the connection portion is firmly maintained even when the internal pressure of the case decreases again as the connection portion between a bottom of the case and a negative current collecting plate is disconnected and the bottom of the case is broken outwardly.
[0019] A secondary battery according to one exemplary embodiment of the present invention includes: an electrode assembly including a positive electrode, a separator, and a negative electrode; a case including an end plate and at least one wall extending therefrom defining an inner cavity, the case housing the electrode assembly in the inner cavity; a cap assembly coupled to the case for sealing the case; a positive current collecting plate including a first side connected to the positive electrode in the case and a second side connected to the cap assembly; an insulator in the case adjacent the end plate; and a negative current collecting plate including a first side connected to the negative electrode and a second side adjacent the insulator and connected to the end plate at a connection portion of the end plate, wherein the end plate is curved convexly toward the inner cavity of the case.
[0020] The insulator may include: an external circumferential surface portion corresponding to an internal circumferential surface of the at least one wall of the case; a planar portion adjacent the negative current collecting plate; and a recessed portion curved concavely toward the inner cavity of the case and contacting the end plate, wherein an aperture extends between the planar portion and the recessed portion near a center of the insulator, and wherein the negative current collecting plate is connected to the end plate through the aperture.
[0021] The negative current collecting plate may further include a protruding portion extending toward and connected to the end plate through the aperture of the insulator at the connection portion.
[0022] A portion of the insulator may face the end plate and be curved. The portion of the insulator facing the end plate may contact the end plate and have a curvature corresponding to a curvature of the end plate.
[0023] The end plate may be invertible convexly away from the inner cavity of the case to provide a separating space between the end plate and the negative current collecting plate. The end plate may be invertible convexly away from the inner cavity of the case to disconnect the negative current collecting plate from the end plate when an internal pressure in the case is greater than a reference operating pressure.
[0024] The end plate may include at least one notch and be collapsible away from the inner cavity of the case at the at least one notch upon an increase of an internal pressure in the case.
[0025] The at least one notch may include at least one outer circumferential notch along at least a portion of an outer circumference of the end plate.
[0026] The at least one notch may include central notches arranged in a cross pattern at the connection portion of the end plate. The end plate may be configured to rupture away from the inner cavity at the central notches when the internal pressure in the case is greater than a rupturing pressure.
[0027] The at least one notch may further include at least one inner circumferential notch connecting the central notches in a circumferential direction.
[0028] A portion of the insulator may face the end plate and have a polyhedron shape. A portion of the end plate may face and contact the insulator and have a polyhedron shape.
[0029] According to another exemplary embodiment of the present invention, a secondary battery having a current interrupt device between a negative current collecting plate of the secondary battery and a case of the secondary battery includes: an electrode assembly including a positive electrode, a separator, and a negative electrode; a case including an end plate and at least one wall extending therefrom defining an inner cavity, the case housing the electrode assembly in the inner cavity; a cap assembly coupled to the case for sealing the case; a positive current collecting plate connecting the positive electrode to the cap assembly; an insulator adjacent the end plate; and a negative current collecting plate connected to the negative electrode and connectable to the end plate at a connection portion of the end plate, wherein the end plate is curved toward the inner cavity of the case and is connected to the negative current collecting plate when an internal pressure in the case is less than a reference operating pressure, and wherein the end plate is curved away from the inner cavity of the case and is configured to be disconnected from the negative current collecting plate when the internal pressure in the case is greater than the reference operating pressure.
[0030] In one embodiment, the end plate includes at least one notch and is collapsible away from the inner cavity of the case at the at least one notch when the internal pressure in the case is greater than the reference operating pressure.
[0031] As set forth above, according to one exemplary embodiment of the present invention, the bottom of the case is protruded inward and connected to the negative current collecting plate at the connection portion through an aperture of an insulator, and is configured such that the connection portion is disconnectable to interrupt current before an explosion of the case, thereby preventing explosion.
[0032] Since the bottom of the case is curved convexly toward the inside of the case and connected to the negative current collecting plate at the connection portion, the connection portion can be designed so as to be disconnected under a predetermined operating pressure, thus reducing the dispersion of the operating pressure of the connection portion.
[0033] Even when the internal pressure of the case decreases after the bottom of the case and the negative current collecting plate are disconnected and the bottom of the case is broken outwardly, the bottom of the case remains inverted concavely away from the inner cavity of the case, thus firmly maintaining a disconnected state of the connection portion. As a result, reliability with respect to current interruption is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a sectional perspective view of a secondary battery according to a first exemplary embodiment of the present invention.
[0035] FIG. 2 is an exploded sectional view of a current interrupt device of the secondary battery of FIG. 1 .
[0036] FIG. 3 is a bottom view of a case of the secondary battery of FIG. 2 .
[0037] FIG. 4 is a sectional view showing a connected state when a connection portion of a current interrupt device is connected.
[0038] FIG. 5 is a sectional view showing a disconnected state when the connection portion of the current interrupt device of FIG. 4 is disconnected.
[0039] FIG. 6 is a sectional view showing a cut away state after the current interrupt device of FIG. 4 is disconnected.
[0040] FIG. 7 is an exploded sectional view of a current interrupt device of a secondary battery according to a second exemplary embodiment of the present invention.
[0041] FIG. 8 is a bottom view of a case of the secondary battery of FIG. 7 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0042] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
[0043] FIG. 1 is a sectional perspective view of a secondary battery according to a first exemplary embodiment of the present invention. Referring to FIG. 1 , the secondary battery according to the first exemplary embodiment includes an electrode assembly 10 , a case 20 , a cap assembly 30 , a positive current collecting plate 40 , and a negative current collecting plate 50 . The case 20 accommodates the electrode assembly 10 and an electrolyte.
[0044] The electrode assembly 10 includes a positive electrode 11 , a separator 12 , and a negative electrode 13 . The electrode assembly 10 is formed by winding the positive electrode 11 , the negative electrode 13 , and the separator 12 of an insulating material disposed therebetween.
[0045] In one example, the electrode assembly 10 may be formed in a cylindrical shape. A sector pin 14 is disposed at the center of the cylindrical electrode assembly 10 . The sector pin 14 maintains the cylindrical shape of the spirally wound electrode assembly 10 .
[0046] The positive electrode 11 and the negative electrode 13 are made of a thin metal foil and form a current collecting body, and include respective coating portions 11 a and 13 a and non-coating portions 11 b and 13 b which are differentiable according to the application or absence of an active material. That is, the coating portions 11 a and 13 a have an active material applied thereto, and the non-coating portions 11 b and 13 b do not have an active material applied thereto.
[0047] The case 20 has a space in which the electrode assembly 10 is inserted, and may be formed in a cylindrical or rectangular shape which is open at one end. The case 20 is connected to the negative current collecting plate 50 , and serves as a negative electrode terminal in the secondary battery. The case 20 is made of a conductive metal, such as aluminum, an aluminum alloy, or nickel-plated steel.
[0048] A cap assembly 30 is coupled with the open end of the case 20 through a gasket 31 configured to seal the case 20 accommodating the electrode assembly 10 and the electrolyte. The cap assembly 30 of the present exemplary embodiment may be provided with a current interrupt device (not shown) or not, as illustrated in FIG. 1 .
[0049] Before a detailed description of the cap assembly 30 is provided, the positive current collecting plate 40 will be discussed. The positive current collecting plate 40 is connected to the non-coating portion 11 b of the positive electrode 11 at the cap assembly 30 side to connect the positive electrode 11 to the cap assembly 30 .
[0050] The cap assembly 30 includes a cap plate 32 and a sub-plate 33 . The cap plate 32 is connected to the positive current collecting plate 40 , and serves as a positive electrode terminal in the secondary battery. The cap plate 32 has a terminal 32 a protruding to the outside and a vent hole 32 b.
[0051] A positive temperature coefficient element 34 is installed between the cap plate 32 and the sub-plate 33 . The positive temperature coefficient element 34 forms or interrupts current flow between the cap plate 32 and the sub-plate 33 . That is, when a preset temperature is exceeded, the electrical resistance of the positive temperature coefficient element 34 increases to a virtually infinite level, thereby stopping the flow of charging or discharging current.
[0052] The sub-plate 33 is installed inside the cap plate 32 and connected to the electrode assembly 10 . That is, the sub-plate 33 is electrically connected to the positive current collecting plate 40 through a connection member 35 .
[0053] An insulating member 36 is provided on the positive current collecting plate 40 . The insulating member 36 covers the periphery of the positive current collecting plate 40 below a beading portion 21 . Hence, the positive current collecting plate 40 is electrically connected to the cap plate 32 through the connection member 35 and the sub-plate 33 .
[0054] After the cap assembly 30 is inserted into the case 20 , the cap assembly 30 is clamped and fixed to the case 20 . Hereupon, the beading portion 21 and a clamping portion 22 are formed, and the gasket 31 provides an airtight seal between the case 20 and the cap assembly 30 .
[0055] The negative current collecting plate 50 is connected to a non-coating portion 13 b of the negative electrode 13 on one side and connected to the case 20 on the other side. In order to construct a current interrupt device (CID) between the negative current collecting plate 50 and the case 20 , an insulator 60 is interposed between the negative current collecting plate 50 and a bottom 23 of the case 20 to thus electrically insulate the negative current collecting plate 50 and the bottom 23 of the case 20 .
[0056] The negative current collecting plate 50 is connected to the bottom 23 of the case 20 at a connection portion CP passing through the interposed insulator 60 . For example, the negative current collecting plate 50 may contact the bottom 23 of the case 20 at the connection portion CP. Upon an increase of the internal pressure of the case 20 , the negative current collecting plate 50 is separated from the bottom 23 of the case 20 at the connection portion CP to thus interrupt current.
[0057] FIG. 2 is an exploded sectional view of the current interrupt device of FIG. 1 . Referring to FIG. 2 , that is, the current interrupt device CID may be formed by the negative current collecting plate 50 and the bottom 23 of the case 20 that are mostly insulated through the insulator 60 and partly connected through the connection portion CP.
[0058] To form the current interrupt device CID, the bottom 23 of the case 20 is curved convexly toward the inside of the case 20 . Further, the bottom 23 of the case 20 is inverted convexly toward the outside of the case 20 and forms a separating space SS during a time from immediately after the bottom 23 of the case 20 is separated from the negative current collecting plate 50 at the connection portion CP due to an increase of the pressure in the case 20 until immediately before the bottom 23 of the case 20 is cut away (see FIGS. 4 and 5 ).
[0059] Before further describing the bottom 23 of the case 20 , the insulator 60 will be described in more detail. The insulator 60 includes an external circumferential surface portion 61 corresponding to the internal circumferential surface of the case 20 , a planar portion 62 supporting the negative current collecting plate 50 ; a recessed portion 63 formed concavely and tightly contacting the bottom 23 of the case 20 , and a through hole 64 penetrated at the center of the insulator 60 from the planar portion 62 to the recessed portion 63 .
[0060] The recessed portion 63 of the insulator 60 may be curved facing the bottom 23 of the case 20 on a cut surface directed toward the negative current collecting plate 50 from the positive current collecting plate 40 , i.e., on a vertical section of FIGS. 1 and 2 . Further, the recessed portion 63 is curved along the circumferential direction and forms an overall three-dimensional curved surface.
[0061] The negative current collecting plate 50 further includes a protruding portion 51 connected at the connection portion CP to the bottom 23 of the case 20 . The protruding portion 51 is connected to the bottom 23 of the case 20 through the through hole 64 of the insulator 60 . Therefore, the protruding portion 51 has a diameter D for insertion into the through hole 64 and a height H for reaching the bottom 23 of the case 20 through the through hole 64 .
[0062] Again, a portion of the bottom 23 of the case 20 that faces and contacts the recessed portion 63 of the insulator 60 is curved on a cut surface directed toward the negative current collecting plate 50 from the positive current collecting plate 40 , i.e., on a vertical section of FIGS. 1 and 2 .
[0063] Further, the bottom 23 of the case 20 is curved along the circumferential direction and forms an overall three-dimensional curved surface. Accordingly, the bottom 23 of the case 20 and the recessed portion 63 of the insulator 60 maintain a stable contact and coupling structure because they have curved surfaces in contact with each other.
[0064] The bottom 23 of the case 20 curved convexly toward the inside of the case 20 and the protruding portion 51 of the negative current collecting plate 50 are connected at the connection portion CP, so that current is interrupted between the negative current collecting plate 50 and the case 20 as the bottom 23 of the case 20 is separated from the connection portion CP upon an increase of the internal pressure of the case 20 .
[0065] The bottom 23 of the case 20 having an inward convex shape makes clear the connection to and disconnection from the protruding portion 51 , thereby reducing the dispersion of an operating pressure of the connection portion CP, which disconnects the connection portion CP at an internal pressure greater than a predetermined operating pressure. Also, the bottom 23 of the case 20 effectively serves to prevent explosion because it forms the separating space SS without explosion as it is disconnected from the connection portion CP.
[0066] FIG. 3 is a bottom view of the case 20 of FIG. 2 . Referring to FIGS. 2 and 3 , the bottom 23 of the case 20 is provided with at least one notch 24 having a thickness less than the circumferential thickness of the bottom 23 of the case 20 . The notch 24 prevents explosion more effectively since it is cut away upon an additional increase of the internal pressure of the case 20 in a state where current is interrupted by the disconnection of the connection portion CP.
[0067] For example, the at least one notch 24 includes one or more outer circumferential notches 241 which are formed along the outer circumference on at least part of the outer circumference of the bottom 23 of the case 20 . The outer circumferential notches 241 may be formed around the entire circumference of the bottom 23 of the case 20 (not shown), or may be divided by a predetermined length into two (e.g., one on both sides, as shown in FIG. 3 ) or more.
[0068] FIGS. 4 to 6 are sectional views showing operating states. FIG. 4 shows a state when the connection portion CP of the current interrupt device CID is connected, and FIG. 5 shows a state when the connection portion CP is disconnected. The outer circumferential notches 241 induce the inversion of the bottom 23 of the case 20 , which is convex toward the inside of the case 20 in a connected operating state, upon an increase of the internal pressure of the case 20 above a predetermined reference pressure, thereby facilitating inversion of the bottom 23 of the case 20 to an outwardly concave position in which the CID is in a disconnected state.
[0069] FIG. 6 shows a cut away state after the current interrupt device has disconnected current flow. Referring to FIG. 6 , even though the internal pressure is reduced due to the outer circumferential notches 241 inducing inversion of the bottom 23 of the case 20 , the separating space SS firmly maintains a disconnected state of the bottom 23 of the case 20 and the negative current collecting plate 50 , thereby improving reliability with respect to current interruption.
[0070] Referring again to FIG. 3 , the at least one notch 24 includes one or more central notches 242 which are formed in a cross pattern at the connection portion CP of the bottom 23 of the case 20 . The central notches 242 may be formed over the entire diameter of the bottom 23 of the case 20 (not shown), or may be formed in a cross pattern at a predetermined length at the center part of the bottom 23 of the case 20 as shown in FIG. 3 .
[0071] The central notches 242 are able to cut away the center part of the bottom 23 of the case 20 even if they are not inverted from the outer circumferential notches 241 . The central notches 242 firmly maintain a disconnected state of the bottom 23 of the case 20 and the negative current collecting plate 50 because they are directed toward the outside of the case 20 as they are cut away around the connection portion CP, i.e., at the center part of the bottom 23 of the case 20 .
[0072] The bottom 23 of the case 20 operated as described above may be provided with either the outer circumferential notches 241 or the central notches 242 at the bottom 23 of the case 20 , or may be provided with both the outer circumferential notches 241 and the central notches 242 , as shown in FIG. 3 .
[0073] When comparing the following second exemplary embodiment with the first exemplary embodiment, descriptions of identical or similar components will be omitted, and different components will be described.
[0074] FIG. 7 is an exploded sectional view of a current interrupt device in a secondary battery according to a second exemplary embodiment of the present invention. FIG. 8 is a bottom view of a case of the secondary battery of FIG. 7 .
[0075] Referring to FIGS. 7 and 8 , a current interrupt device CID 2 according to the second exemplary embodiment is provided within a through hole 64 of an insulator 260 , and where a recessed portion 263 of the insulator 260 and a bottom 223 of a case 220 face and contact each other is formed in a polyhedron. A polygonal line of the recessed portion 263 may be shown on a cut surface directed toward the negative current collecting plate 50 from the positive current collecting plate 40 , i.e., on a vertical section of FIG. 7 .
[0076] Further, the recessed portion 263 is formed in a curved line along the circumferential direction of the bottom 223 of the case 220 to form a plurality of curved surfaces divided at angulated parts of the polygonal line. Accordingly, the bottom 223 of the case 220 and the recessed portion 263 of the insulator 260 are in linear contact with each other at the angulated parts, and are in surface contact with each other at the other parts, thereby maintaining a stable contact and coupling structure.
[0077] The bottom 223 of the case 220 includes at least one notch 224 which further includes inner circumferential notches 243 which are formed in a circumferential direction between the central notches 242 and the outer circumferential notches 241 . The inner circumferential notches 243 may be formed in a singular number (not shown), or may be formed in a plural number having a pattern of concentric circles as shown in FIG. 8 .
[0078] Therefore, the inner circumferential notches 243 are formed by connecting the central notches 242 in the circumferential direction. The inner circumferential notches 243 enable the bottom 223 of the case 220 to be cut away between the center part and outer circumferential part of the bottom 223 of the case 220 even if the outer circumferential notches 241 are not inverted. The bottom 223 of the case 220 forms angulated parts at the at least one notch 224 , and comes into contact corresponding to the angulated parts formed on the recessed portion 263 .
[0079] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
|
A secondary battery having a current interrupt device (CID) between a negative current collecting plate and a case of the secondary battery. The secondary battery includes: an electrode assembly including a positive electrode, a separator, and a negative electrode; a case housing the electrode assembly; a cap assembly coupled to the case for sealing the case; a positive current collecting plate connected to the positive electrode and the cap assembly; an insulator in the case adjacent an end plate of the case; and a negative current collecting plate connected to the negative electrode and the end plate of the case, the end plate being curved convexly toward an inner cavity of the case.
| 7
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of international patent application no. PCT/EP00/06914, filed Jul. 19, 2000, designating the United States of America, the entire disclosure of which in incorporated herein by reference. Priority is claimed based on Federal Republic of Germany patent application no. DE 199 33 872.8, filed Jul. 23, 1999.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a method of producing microbore holes and to an apparatus for producing microbore holes. A method and an apparatus for producing microbore holes of the aforementioned type are known from published European Patent Application No. EP 884,128. According to this document, a substrate is arranged on an XY stage or table which can be positioned along X and Y coordinates in the desired treatment positions, whereby the bore hole coordinates of the borings to be introduced and additional information such as bore hole diameter are provided by a computing system. In order to enable the production of bore holes with diameters of 50 μm or less using a conventional CO 2 laser, the laser beam is converted to a beam having a small wavelength, using a tellurium crystal. Changing the diameter of the beam or the spot is not described.
[0003] Furthermore, it is problematic that when the laser power is increased to produce larger bore hole diameters, instead of a cylindrical bore hole a conical expansion of the bore hole can occur as a result of focusing the laser beam.
[0004] In addition, a method and an apparatus for treating substrates are known from U.S. Pat. No. 5,690,846, in which errors resulting from distortions and/or faulty alignments of the substrate can be compensated for by using a special computer method. There is no reference therein to influencing the diameter of the spot.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a new method of the aforementioned type so as to enable rapid and reliable production of bore holes having different diameters.
[0006] Another object of the invention is to provide a new apparatus of the aforementioned type with which bore holes having different diameters can be rapidly and reliably produced.
[0007] These and other objects are achieved in accordance with the present invention by providing a method of producing microbore holes in a multilayer substrate that is displaced below writing optics by an XY stage, wherein the writing optics generate a spot from a light beam source; the position of the light spot within a working field is changed simultaneously with substrate treating positions by a positioning unit comprising electronically controlled, movable mirrors; the position of the substrate is determined; signals corresponding to the substrate position are processed by a computer to obtain an actual position of the XY stage, and the diameter of the spot is changed by an expansion ratio determined by the computer, using variable beam expansion optics.
[0008] In accordance with another aspect of the invention, the objects are achieved by providing an apparatus for producing microbore holes in a multilayer substrate comprising writing optics for generating a light spot from a light beam source; an XY stage for moving the substrate to different treatment positions below the writing optics; the writing optics including a beam deflecting unit comprising electronically controlled, movable mirrors for changing the position of the light spot within a working field on the substrate simultaneously with the treatment positions; means for determining the position of the substrate, and a computer for processing signals corresponding to the substrate position to obtain an actual position of the XY stage, wherein the writing optics further comprise a variable beam expansion optics arranged in a light beam path between the light source the beam deflection unit; the variable bean expansion optics outputing a light beam having a diameter that is varied according to an expansion ratio determined by the computer.
[0009] In the method and apparatus of the invention, the light from a pulsed laser, for example UV light from a frequency-multiplied Nd:YAG laser or infrared light from a CO 2 laser, can be used to produce bore holes in materials used in the production of electronic printed circuit boards. The parameters of the light source and the optics used, such as the laser power, pulse duration, and size of the spot, are generally known to persons skilled in the art. Treatment systems of the current art basically comprise an XY stage that positions the substrate to be treated below an optical structure that is appropriate for the optical requirements. The optical structure performs two functions. First, it produces an intense pulsed laser spot for treating the substrate at the required position. Second, it determines the position by recognizing preset substrate marks from previous production steps. This step requires an image processing system comprising an electronic camera and a suitably equipped computer system that determines the desired positional information from the camera signals.
[0010] The overall precision of the position of the bore holes in the substrate relative to the preset marks is determined by the positional precision of the XY stage system, and the precision of spot positioning of both the optical beam forming system and the optical measuring system. In modern printed circuit boards constructed from a plurality of layers of conductors and insulation materials, material distortions occur during the individual production steps, making it necessary to adapt the bore hole patterns to the individual distortion of the base substrate. This in turn requires very high precision in the measuring and positioning of the XY stage system and the beam optics.
[0011] For economic reasons it is necessary to minimize as much as possible the overall treatment time as well as the time for each bore hole to be produced. Depending on the particular application or the technology of the printed circuit boards, bore hole diameters of a few tenths of a millimeter down to 50 μm should be maintained. Since the spot diameter of the laser beam is approximately 25 μm for typical UV laser treatment systems, bore hole diameters that deviate from this value must be created by lining up individual treatment steps, identified hereinafter as “passes.” The removal of material by multiple passes along a production line, suitably chosen and generally spiral-shaped, is referred to as “nibbling.” Although this method allows bore hole diameters to be produced in any size, it has the disadvantage of being very time-consuming.
[0012] Since the energy requirements per pass depend greatly on the material to be treated, an optimized treatment strategy is desirable. If sufficient energy is available for each laser pulse, the throughput is significantly increased if instead of the nibbling method a more suitable, larger spot diameter is chosen, and only one pass removes the required amount of material for the desired bore hole diameter. The basis of the novel method described here is that the spot diameter of the laser beam used for treatment may be varied within a very short time, thus producing bore images of different diameters in a single operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawings, in which:
[0014] [0014]FIG. 1 is a schematic representation of an illustrative embodiment of an apparatus according to the invention;
[0015] [0015]FIG. 2 is a schematic illustration of the light beam path in an apparatus for carrying out the invention;
[0016] [0016]FIG. 3 is a schematic illustration of the image processing component of an apparatus for carrying out the invention;
[0017] [0017]FIG. 4 is a schematic representation of the controllable beam expansion in the apparatus of FIG. 1, using galvanometer mirrors;
[0018] [0018]FIG. 5 is a schematic representation of an infinitely adjustable beam expansion unit which uses active mirror elements;
[0019] [0019]FIG. 6 is a schematic representation of the beam path for measuring and regulating the beam expansion using an active mirror;
[0020] [0020]FIG. 7 is a schematic representation of a variable beam positioning unit in the apparatus of FIG. 1, which uses piezo-driven adjustable mirrors;
[0021] [0021]FIG. 8 is a schematic representation of a variable beam positioning unit in the apparatus of FIG. 1, which uses acousto-optical deflectors;
[0022] [0022]FIG. 9 is a schematic representation of a variable beam positioning unit in the apparatus of FIG. 1, which uses galvanometer-driven adjustable mirrors; and
[0023] [0023]FIG. 10 is a schematic representation of the of the deflection unit control.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] A laser used as a light source, for example a frequency-tripled Nd:YAG laser, is designated by 1 in FIG. 1. The laser emits a brief, very powerful light pulse with a duration of approximately 10-20 ns and energy of approximately 10 −4 Joule as soon as a start signal from the control computer 16 arrives at the laser electronic system 18 . The light 20 emitted by the laser enters the variable beam expansion optics 2 . The diameter of the output beam 21 varies in accordance with the expansion ratio, which is determined by the control unit 17 of the computer 16 , as detailed in FIGS. 4, 5, and 6 .
[0025] The light entering the beam deflection unit 3 is conducted through two deflection units, in accordance with the control signals from the control unit 14 , as shown in FIGS. 7, 8, and 9 . As a result, the exiting beam 22 enters the lens 4 at modifiable angles of incidence that can be separately controlled in the X and Y directions. The lens images the incident light, which strikes as a flat wave, in a beam spot—hereinafter referred to as a “spot”—on the substrate 5 to be treated. The XY position at which the spot strikes the substrate 5 within the write window 23 depends on the angle of incidence in the lens and the focal length of the lens, as shown in FIG. 2. At small angles of deflection (α<8 mrad, see detail 24 in FIG. 2), a deflection (see detail 25 in FIG. 2) and thus a write window according to equation [1]
δx=α * F [1]
[0026] of approximately 2-4 mm can be achieved. The diameter (see detail 27 in FIG. 2) of the spot on the substrate depends on the diameter (see detail 26 , FIG. 2) of the incident light beam:
d= 1.21 * λ * F/D [2]
[0027] where
[0028] δx=spot position relative to the write window
[0029] α=angle of incidence
[0030] F=focal length of the lens
[0031] d=diameter of the spot
[0032] λ=wavelength of the light used
[0033] D=diameter of the incident beam
[0034] For small beam deflections a large spot is obtained on the substrate, and for large deflections the light is focused more tightly, and a smaller spot diameter and, thus, a smaller bore hole diameter on the substrate are obtained.
[0035] The substrate 5 to be treated is secured to the XY stage by appropriate measures such as vacuum suction or a clamping device. Two interferometer mirrors, an X mirror 7 and a Y mirror 10 , are situated on the XY stage at the same height as the substrate. By use of interferometer measuring heads, an X measuring head 9 and a Y measuring head 11 , the position of the XY stage at the time is measured at high resolution and speed. The signals from the interferometer system are fed to the XY stage positioning electronic system 13 and to the beam divergence control 14 . The positioning unit 13 controls the drive units of the XY stage to produce the line or course or movement specified by the computer 16 . Finally, an image recording and treatment unit 15 is provided. The image recording unit shown in FIG. 3 corresponds to a reflected light microscope which comprises a light source 29 , illumination beam path 30 , and lens 31 , as well as an electronic camera 32 and a field lens 33 arranged in front of the camera. The signals from the camera are supplied to the local image processing computer 34 . The beam path of the image recording is disposed parallel to the treatment beam path, so that by moving the XY stage the entire substrate can be placed below the camera lens 31 and is thus made available to the image processing computer for measurement purposes.
[0036] Components 13 through 18 are connected to one another by a heterogeneous bus system 19 . The image processing unit 15 and control unit 14 for beam divergence are connected to the central control computer 16 via a parallel data bus because of the larger data volumes to be exchanged.
[0037] The course of the treatment process according to the invention will now be described.
[0038] Substrate 5 , which is affixed to the XY stage 6 , is positioned below the write lens 4 in such a way that the bore hole coordinates lie within the write window 23 . If the XY stage 6 has approached the coordinates X stage , Y stage and the beam divergence unit 3 in conjunction with the lens 4 has a scan region of δx, δy according to equation [2], all bore holes having coordinates in the range of
X stage −δx<X bore hole <X stage +δx [3]
Y stage −δy<Y bore hole <Y stage +δy
[0039] can be treated. The control signals for the beam divergence 3 are calculated by the computer 16 from the target bore hole coordinates and the stage coordinates. Both sets of coordinate values, hereinafter referred to as “ticks,” are present in the base units of the interferometer. The size of these ticks depends on the working principle of the interferometer and the wavelength of the light used.
[0040] An HeNe laser, which emits light with a wavelength of approximately λHeNe 633 nm, is typically used. This results in a tick size of approximately λHeNe/16 40 nm, for example. After the positioning process is completed, the location of the XY stage has the following coordinates:
X stage actual =X stage, target +ε x [4]
Y stage actual =Y stage, target +ε y
[0041] where ε x and ε y denote the static position errors of the XY stage system.
X defl. =X bore hole −X stage, target −ε x [5]
Y defl. =Y bore hole −Y stage, target −ε y
[0042] The calculated values X defl. and Y defl. thus compensate for the position errors of the XY stage system. The result
X defl. =X bore hole −X stage, actual [6]
Y defl. =Y bore hole −Y stage, actual
[0043] is initially present as an integer value in tick units. To control the beam divergence, however, an analog voltage, for example in the range of 0-10 volts, is generally required, the voltage being obtained from a digital/analog converter unit which is charged by the computer. There is a fixed association or relationship of the input voltage of this component and the written value. The calculated values for the beam divergence, therefore, must be scaled. This scaling operation requires additional computing capacity when it is program-controlled in the computer.
[0044] If, in addition, there is a nonlinear relationship between the control voltage of the beam divergence unit and the divergence produced, the necessary computing operations can be performed only by a very fast, and thus expensive, computer. For this reason, the scaling operation preferably is carried out by a hardwired electronic component within the control system of the divergence unit 14 , as shown in FIG. 10.
[0045] [0045]FIG. 10 shows the components for controlling a beam divergence channel, where X and Y are configured identically. In a one-time preparation step, a scaling table is loaded into memory 73 . The computer writes the desired address to the forward/backward counter 72 , which functions as an input register, and writes the corresponding data to the access control 75 . In this phase the digital/analog converter 74 is deactivated. To carry out the scaling operations, the computer places the calculated X defl. and Y defl. values on the position counter, the outputs of which address memory 73 . The value read from memory is transmitted to the digital/analog converter 74 and thus determines the control voltage for the beam deflection unit 3 . For every possible input value, a scaled output value must be held in memory 73 .
[0046] The range of deflection values from equation [6] is limited by the optically possible deflection range. If one starts with an address capacity of 20 bits in memory 73 , 2 20 ≅1,000,000 values may be stored. For a tick size of 40 nm, there results a maximum deflection range of approximately 40 mm. Since the address range may be easily expanded, operating ranges over 100 mm are possible, and for all practical purposes are limited only by the optically possible range.
[0047] For large-surface substrates a low throughput is obtained with the aforementioned method, since the XY stage system must carry out a positioning process for each treatment field. To avoid this, the XY stage system is allowed to move continuously, in which case the dynamic error now must be compensated for. During continuous stage motion the laser spot must track the substrate motion in order to carry out multiple treatments at the same substrate site. If the XY stage system moves at velocities v x and v y , the laser beam must be tracked, and deflected as a function of time, as follows:
X defl. ( t )=X bore hole −X stage, actual at T0 =v x * t [7]
Y defl. ( t )=Y bore hole −Y stage, actual at T0 =v y * t
[0048] The deflection values are composed of a static portion that depends only on the coordinates of the bore hole to be produced and on the stage coordinates, which may be chosen, in addition to a component that is determined by the XY stage velocity at the time. In this mode of operation the XY stage 6 together with the substrate 5 moves at a velocity, not necessarily constant, along the Y axis, for example. The computer 16 calculates the required deflection values and compares them to the maximum possible values. As soon as these values are sufficiently small, i.e., when the bore hole coordinates appear in the treatment window, the static portion is calculated from equation [7] as follows
X start =X bore hole −X stage, actual at T0 [8]
Y start =Y bore hole −Y stage, actual at T0
[0049] and is loaded into the counter 72 . The dynamic error v * t is compensated for by counting the interferometer signals in the counter 72 . At a XY stage velocity of 100 mm/second, for example, in the Y direction, and an interferometer resolution, or tick size, of approximately 40 nm, about 2.5 * 10 6 count signals are delivered from the interferometer 11 to the Y counter 72 at an average time interval of approximately 400 ns. The output of this counter thus represents the continuously changing deflection value for the Y axis, and is scaled and used to control the beam deflection unit 3 . Since identically configured deflection controls are present for both axes of motion according to FIG. 10, the vectorial direction of motion is not limited.
[0050] Because the counter 72 , which is identical for the X and the Y directions, is designed as a forward/backward counter, both positive and negative dynamic errors can be compensated for. The type of motion of the XY stage system can therefore be freely chosen, and can be optimized for increased throughput.
[0051] In the foregoing description of the invention, it has been assumed that the bore hole coordinates represent fixed values. Since multilayer substrates in particular must pass through very different types of process steps during production, the dimensional stability of same is provided only to a limited extent. Because the positions of the bore holes at different locations are determined in relation to one another, specified position tolerances must not be exceeded. However, this would occur if the bore hole coordinates were held fixed, that is, independent of the substrate currently being treated.
[0052] If the material behavior were fully known and the process steps were not subject to variability, the bore hole coordinates could be corrected in advance. However, since process and material parameters are subject to variability, advance correction is practical only for appropriately small substrates. Because the residual errors are generally proportional to the substrate size in spite of advance correction, such a method is not acceptable for large substrates. Dynamic correction of the substrate distortions allows this limitation to be overcome.
[0053] The first step in this embodiment of the inventive method is measurement of the substrate. Markers or alignment marks whose target coordinates are known must be present on the substrate. These marks were created in the preceding treatment step, for example, and must be exposed, if needed, in order to be optically detectable by the camera system 15 . Depending on the number of available marks, different errors or distortions may be detected and compensated for.
[0054] Measurement of the substrate initially involves determination of the absolute coordinates of the marks in relation to the XY stage coordinate system. To this end, the XY stage 6 positions the substrate 5 in such a way that the alignment marks appear in the image field of the camera system 15 . The associated image processing computer determines the coordinates relative to the midpoint of the image field. The absolute coordinates are obtained by adding the screen coordinates, that is, the distance between scaled picture elements, and the XY stage coordinates are measured by the interferometer heads 9 and 11 . By measuring one mark, the XY stage coordinate system used can be displaced so as to be congruent with an imaginary coordinate system on the substrate. However, due to substrate distortion, this congruence can be assured only for the one measured mark. By measuring another mark and comparing the target position of same, possible twisting of the substrate
φ=(Y actual, mark 1 −Y actual, mark 2 )/(X actual, mark 1 −X actual, mark 2 ) [9]
[0055] in the direction of motion of the XY stage, and a longitudinal distortion
ξx=(X actual, mark 1 −X actual, mark 2 )/(X target, mark 1 −X target, mark 2 ) [10]
[0056] in one axis are determined. In equations 9 and 10, it is assumed that both marks are situated at the same height, that is, having identical Y coordinates, and on the left and right edge of the substrate. In general this is not an absolute prerequisite, in which case this method is not changed; however, the misalignments in the X and Y directions that are known at that time must be inserted in the equations.
[0057] If additional alignment marks are available, measurement of these marks determines the longitudinal distortion in the Y direction, analogous to equation 10 , or, by averaging, improves the accuracy of measurement. After the first step involving parameterization of the contact error and detection of the substrate distortion is concluded, these effects are compensated for during the treatment process.
[0058] Particularly for substrates that contain multiple printed panels, a distinction is made between global contact errors and local parameters that may be determined separately for each panel. The global contact errors are compensated for by translation and rotation of the XY stage coordinate system. To compensate for the local distortion effects and optionally for the rotation or translation of individual panels that appears relative to the overall substrate, the bore hole coordinates must be transformed separately for each panel:
X bore hole =G xx * X design +G xy * Y design +G zz [11]
Y bore hole =G yz * X design +G yy * Y design +G yz
[0059] The numerical values of the transformation parameters G ij are calculated from the measured distortion parameters.
[0060] The essence of the method according to a preferred embodiment is that after all relevant distortion parameters have been detected, the bore hole coordinates that are present in ideal design coordinates are transformed into a real coordinate system during the treatment phase, and the variation of the parameters is taken into account for multiple purposes on a substrate, thereby minimizing the expense for memory space and the ensuing computing and comparison operations.
[0061] The throughput must be maximized to enable economic operation of a production unit according to this invention; that is, the treatment time per boring must be minimized. The material required to be removed to produce the boring depends on the energy density on the substrate surface. For a relatively weak laser, the laser beam must be tightly focused to achieve appreciable removal; that is, the diameter of the hole for a one-time operation of the laser must be small in relation to the hole diameter required by the design. The combination of treatment steps is very time-intensive, and may be avoided if the spot diameter can be adapted to the bore hole diameter. In another preferred embodiment of the invention, the size of the spot may be varied quickly by modifying the beam expansion. FIG. 4 shows a basic schematic of the arrangement for stepwise modification of the beam diameter. The arrangement comprises expansion lenses arranged in pairs, the distance between the lenses corresponding to the sum of their focal lengths, so that a parallel ray bundle undergoes a fixed expansion as follows:
[0062] F1/F2=D1/D2 [12]
[0063] where
[0064] F1=focal length of the entry lens
[0065] F2=focal length of the exit lens
[0066] D1=beam diameter at entry
[0067] D2=beam diameter at exit
[0068] Switching the beam path provides a plurality of fixed expansions for selection. Switching is performed by the galvanometer mirrors 35 and 36 . Auxiliary mirrors are necessary to enable parallel mounting of the pair of expansion lenses.
[0069] An additional optical system is used to allow infinitely variable expansion, as shown in FIG. 5. The system comprises two active mirror elements 41 and 42 . The incident parallel beam diverges after reflection on the convex mirror 42 . After reflection on the concave mirror 41 , the beam is once again parallel under the following condition:
a=f 3+ f 4 [13]
[0070] where
[0071] a=distance from the mirror
[0072] f3=focal length of the concave mirror
[0073] f4=focal length of the convex mirror
[0074] D3=beam diameter for mirroring
[0075] D4=beam diameter after variable expansion For the ratio of the beam diameters in front of and behind this arrangement, the following equation, analogous to [12], applies:
f3/f4=D3/D4 [14]
[0076] By appropriate choice of the angle of incidence, the laser beam may be caused to undergo multiple reflections on the mirror pair. Since the beam diameter is expanded upon each pass according to equation [14], the total effect on the laser beam increases exponentially. The resulting overall expansion is as follows:
D out =D in * (f3/f4) N [15]
[0077] where
[0078] D out =beam diameter after variable expansion
[0079] D in =beam diameter before variable expansion
[0080] N=number of multiple reflections
[0081] When N =8, for example, is reached, an expansion of approximately 10%, that is, D3/D4=f3/f4 1.1, is sufficient to achieve a twofold overall expansion. An infinitely variable choice of beam diameter, and thus the size of the spot on the substrate, is made possible in conjunction with the beam expansion graduated to a power of 2, as shown in FIG. 4. Switching, i.e., changing the beam diameter, is performed on the one hand by changing the control signal for the galvanometer rotating mirror in the arrangement shown in FIG. 4, so that the laser beam is conducted through another lens pair. On the other hand, in a parallel procedure the control voltage of the active mirror pair is modified as shown in FIG. 5.
[0082] The focal length of an active mirror is a function of the applied voltage, as well as a number of material factors and the chosen operating conditions. To obtain a stable and, in particular, reproducible operating procedure, a control loop may be used to check the control voltages of the active mirrors. FIG. 6 shows the beam path used to measure the beam expansion through the active mirrors. Starting with a light source such as a semiconductor laser 43 , a parallel ray bundle is produced using a pinhole aperture 44 , a collimator lens 45 , and a circular aperture 46 . This ray bundle is split by a beam splitter 47 into a reference beam and a measurement beam. The measurement beam is conducted through the mirror 47 parallel to the exit beam, and then through the active mirrors 41 and 42 . The measurement beam passes through the mirror arrangement twice, since after exiting, the beam is sent back through two auxiliary mirrors 49 and 50 . If the active mirrors are controlled correctly, the measurement beam exits the mirrors parallel to the axis of incidence and is shifted by a defined distance. Both of these parameters are recorded by imaging the measurement and reference beams on two sensors. The two beams are split by a beam splitter 52 . Both beams are imaged once via the auxiliary mirror 51 and the collimator lens 53 onto a line sensor 57 as points.
[0083] If the measurement beam is no longer parallel to the reference beam, the two picture elements are not congruent with the line sensor. The beams that have been uncoupled by the beam splitter 52 illuminate a semicircular screen 54 . This screen is imaged on another line sensor 56 by a lens 55 . The parallel shift of the measurement and reference beams may be determined from the profile of the output signal of this sensor. The measurement signals are preprocessed and act as actual value signals for the computer 58 , thus allowing the signals corresponding to the required target values to be calculated for the electronic control system.
[0084] The beam divergence will now be described. The described invention requires rapid and precise beam divergence. The methods described below are suitable for this purpose.
[0085] To perform the beam divergence required in this invention, the expanded laser beam is guided via two galvanometer mirrors arranged perpendicular to one another, as shown in FIG. 9. The actual value signals that reproduce the mirror position are used in the deflection control 14 in such a way that the mirrors 69 and 71 , with the assistance of the galvanometer drives 68 and 70 , are configured so that the static position error is compensated for and/or the mirror is tracked so that the dynamic position errors disappear. Galvanometer mirrors allow a large deflection region, but because of their structural shape they require a large distance from the write lens 4 .
[0086] If a smaller angle of deflection can be used, piezomirrors are suitable for ray deflection, as shown in FIG. 7. The piezodrives 60 and 62 tilt the respective scan mirrors 61 and 63 to obtain the required beam deflection. An ideal telecentric ray path may be achieved by use of two-axis piezomirrors.
[0087] Although piezomirrors perform positioning significantly faster, there is still a marked delay between the output of the required target position via the computer and reaching the corresponding actual position via the mirror. A distinctly lower positioning time results when the beam deflection is produced by acousto-optical deflectors, as shown in FIG. 8. For deflection, a diffraction grid is produced in crystals 64 and 66 by an acoustic wave. The angle of deflection is proportional to the spatial density of the diffraction grid, thereby allowing an infinitely variable adjustment to be made by changing the frequency of the control signal (approximately 100-200 MHz) supplied by transducers 65 and 67 , respectively. Since in this method only the filling time for the crystal, which is approximately 30 μs for a crystal size of about 20 mm, and a typical acoustic velocity of approximately 600 meters/second represent a time limitation, this device is optimally suited for rapid and precise beam deflection.
[0088] The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention my occur to persons skilled in the art, the invention should be construed broadly to include all variations falling within the scope of the appended claims and equivalents thereof.
|
A method of producing microbore holes in a multi-layer substrate ( 5 ), preferably a printed circuit board substrate, that is displaced below writing optics ( 4 ) by an XY stage ( 6 ), using the optics to generate a spot from a light source ( 1 ), preferably a laser. The method reduces the treatment time and preferably compensates for distortions in the substrate material. To this end, the position of the spot within a working field is changed simultaneously with the treatment positions by electronically controlled, movable mirrors. The position of the substrate is determined by an interferometer ( 9, 11 ), and the signals corresponding to the substrate position are processed by a suitable computer system ( 16 ) to obtain an actual position of the table system. The computer system ( 16 ) is preferably provided with all bore hole coordinates and additional information such as bore hole diameter, especially in tabular form.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] This invention relates generally to surgical instruments, and more particularly to retractor instruments and methods.
[0003] Minimal access surgery or percutaneous surgery utilizes a small skin incision approximately 10 mm long. A muscle-tissue dilator is then inserted through the incision in order to further expand the wound to about 24-32 mm in diameter to facilitate the insertion of surgical instrumentation and implants. The muscle-tissue dilator is a surgical retractor that reduces the need for large, open incisions, tissue scarring and pain.
[0004] Prior methods and devices for retracting incisions utilize a series of rigid tubes of varying diameters and lengths. Each tube is sequentially-sized of increasing diameter such that one can be fitted over the other and individually pushed through the incision, fascia, and muscle bed toward the surgical site of interest. The tubes cannot be pushed too deeply, as they may strike vital structures such as the spinal cord, nerves, or blood vessels. The potential for improper placement and manipulation of the tubes may be dangerous and commonly requires x-ray imaging during each successive tube placement to verify tube position. As only a portion at the end of the tube serves to pry open tissue during placement, strong muscle resistance acts to expulse the tube, which sometimes results in the necessity to reposition the tube. This process is prone to placement error, dangerous manipulation, increased radiation exposure, and additional surgical time. It would therefore be desirable to provide a retractor device and method which save time and do not require repetitive manipulation, avoid undue force in placement in the incision, require less x-ray (radiation) exposure to the patient and medical staff, and which will effectively retain a proper position in the incision.
SUMMARY OF THE INVENTION
[0005] A retractor for surgery includes a retractor body and an elongated and expandable structure attached to the retractor body. The expandable structure, when expanded, has an elongated open interior for the insertion of a portion of a surgical instrument. Drive structure is provided for expanding the expandable structure.
[0006] The expandable structure can have any suitable construction. In one aspect, the expandable structure is an elongated coil. The drive structure expands and retracts the diameter of the coil. The drive structure can be any suitable structure. In one aspect, the drive structure comprises gears which engage the coil at drive surfaces.
[0007] The expandable structure in another aspect comprises at least first and second portions. The drive structure moves the first and second portions relative to one another. The first and second portions can be curved or substantially C-shaped (semi-circular or elliptical) in cross-section.
[0008] The drive structure can be moveable within the retractor body or can be external to the retractor body and lockable in position to maintain retractor body securely in a desired position unless unlocked to resume opening or closure of retractor body. A K-wire can be provided to assist in positioning the device.
[0009] In another aspect, the expandable structure comprises retractor arms. The drive structure is operable to expand the retractor arms.
[0010] A retractor system for surgery comprises a retractor body having elongated and expandable structure attached to the retractor body. The expandable structure, when expanded, has an elongated open interior space for the insertion of a surgical instrument. Drive structure is operable to expand the expandable structure. At least one surgical instrument is positionable in the open interior space. These include bone drill bits, curettes, probes, endoscopes, cautery devices, as well as other instruments.
[0011] A method for retracting an incision includes the steps of providing a retractor comprising a retractor body with elongated and expandable structure attached to the retractor body. The expandable structure, when expanded, has an elongated open interior space for the insertion of a surgical instrument. Drive structure is provided for expanding the expandable structure. The retractor is inserted into the incision. The drive structure is then operated to expand the expandable structure. A surgical instrument can then be inserted at least in part through the open interior space of the expandable structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] There is shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention can be embodied in other forms without departing from the spirit or essential attributes thereof, wherein:
[0013] FIG. 1 is a perspective view of a retractor system according to the invention.
[0014] FIG. 2 is an exploded view of a retractor system according to the invention.
[0015] FIG. 3 is a perspective view of a retractor system in a closed position with transmission gear cover removed for visualization of the drive mechanism.
[0016] FIG. 4 is a perspective view of a retractor system in the open position.
[0017] FIG. 5 is a perspective view of a retractor according to the invention in an open position.
[0018] FIG. 6 is a cross-section taken along A-A in FIG. 5 .
[0019] FIG. 7 is a cross-section taken along B-B in FIG. 5 .
[0020] FIG. 8 is a perspective view of a retractor according to an alternative embodiment.
[0021] FIG. 9 is a cross-section of expandable structure according to an alternative embodiment.
[0022] FIG. 10 is a side elevation, partially broken away and partially in phantom, of drive structure in a first position.
[0023] FIG. 11 is a side elevation of drive structure in a second position.
[0024] FIG. 12 is a perspective view, partially broken away and partially in phantom, illustrating a retractor according to an alternative embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0025] There are shown in FIGS. 1-7 an embodiment of a retractor 30 having expandable structure 38 and drive structure 40 . The expandable structure 38 can have any suitable shape, but is at least in part elongated and, when in the open position, has an open interior space into which can -be positioned a surgical instrument. The expandable structure 38 shown in FIGS. 1-7 is an elongated coil, although other expandable structures are possible. The elongated coil 38 connects to the drive structure 40 such that the drive structure 40 is operable to expand the coil from a closed position, shown in FIG. 3 , to an open position shown in FIG. 4 .
[0026] The manner in which the drive structure 40 expands the expandable structure 38 can be varied. In the embodiment shown in FIGS. 1-7 , the elongated coil 38 includes slots 44 defining drive surfaces 48 . The drive structure 40 includes an elongated shaft 52 ( FIG. 2 ) having gears 56 having gear teeth 60 which engage the slots 44 . Suitable structure such as a drive head 64 is provided for engaging and rotating the shaft 52 . In this manner, the teeth 60 of gears 56 are moved within slots 44 and engage the drive surfaces 48 to expand the coil 38 from the closed position to the open position. In a reverse direction of rotation, the action of the drive structure 40 retracts the coil from the open position to the closed position. A cover 66 can be positioned over the drive shaft 52 to prevent tissues from entering the drive structure.
[0027] The device can be made by any suitable process. In one process, the elongated coil 38 is manufactured from a planar sheet of material. Locking tabs 68 are folded over the elongated shaft 52 between the gears 56 so as to secure the shaft 52 to the coil. The opposite end of the planar sheet is then rolled into a coil and the slots 44 engaged to the teeth 56 to hold the sheet in the coiled position. The cover 66 can then be positioned over the shaft 52 and tabs 68 .
[0028] Operation of the drive structure causes the coil 38 to unwind from the closed position shown in FIG. 3 to the open position shown in FIG. 4-7 . As shown in FIG. 4 , the expanded diameter defines an open interior space 76 into which a suitable surgical instrument can be inserted, such as bone drill bits, curettes, probes, suction, cautery, endoscope and other surgical instruments.
[0029] Other structure can be provided with the retractor. There is shown in FIGS. 1-2 a K-wire 70 which passes through a head 74 . The head 74 can rest or temporarily attach onto an edge 82 of the coil 38 when the coil 38 is in the closed position, as shown in FIG. 1 . The K-wire 70 , as is known in the art, has a positioning point 78 which is driven into the bone or soft tissue in order to guide the device and possibly other surgical devices. Expansion of the coil 38 after insertion permits the removal of the K-wire and/or head 74 as desired. The head 74 can have a suitable bore through which the K-wire 70 is mounted, such that the head 74 can be removed while the K-wire 70 remains in place to guide surgical instruments.
[0030] There is shown in FIG. 8 an alternative embodiment 100 in which drive structure 104 is provided and connected to expandable structure 108 . The expandable structure 108 is comprised of a first section 114 and second section 118 which are semi-cylindrical and mated. Operation of the drive structure, as by operation of a drive head 128 , causes rotation of the shaft 104 which causes the sections 114 , 118 to slide past one another from a closed position to an open position. Locking structure can be provided to prevent the ends of the sections 114 , 118 from moving past one another. These can be interlocking hooked portions or a groove and protrusion configuration.
[0031] There is shown in FIGS. 9-11 an alternative embodiment. In this embodiment, expandable structure 130 comprises a fixed internal tube 132 and mated sections 134 , 138 , which are generally semi-spherical in cross-section as shown. The sections 134 and 138 can move past one another. Protruding ends 140 prevent the sections 134 and 138 from becoming disengaged.
[0032] Drive structure is provided to drive the sections 134 and 138 of the expandable structure 130 apart from a closed to an open configuration. Any suitable drive'structure is possible. There is shown in FIG. 10 a drive structure having a drive wedge 162 and arms 170 . Operation of the wedge 162 is by a T-handle 166 which causes threads 168 to advance the drive wedge 162 and open drive arms 170 from the closed position shown in FIG. 10 to the open position shown in FIG. 11 . This action will cause the first section 134 to move away from the section 138 such that the expandable structure 130 moves from the open position to the closed position.
[0033] There is shown in FIG. 12 an alternative embodiment 200 . In this embodiment, a elongated body 204 has expandable structure comprising arms 208 . The arms 208 are joined to a screw block 210 by members 212 . The members 212 are pivotally connected at connections 216 to the drive block 210 and by pivotal connections 220 to the arms 208 . A drive handle 240 is provided and operated by a threaded member 246 . Rotation of the handle 240 , and thereby threads 246 , causes advancement of the screw block 210 and opening of the expandable arms 208 from the closed position shown in FIG. 12 to the open position shown by phantom lines in FIG. 12 . A K-wire 260 can be threaded through an opening 264 to assist in positioning of the device. The device can be removed while the K-wire 260 remains in place.
[0034] According to a method of the invention, a retractor according to the invention is positioned in an incision. Drive structure is operated to expand elongated expandable structure from a closed position to an open position. This expansion can incremental or be substantially continuous, such that the expandable structure can be expanded to any of a plurality of different dimensions. An open interior within the expandable structure provides the insertion of a surgical instrument. Also, an access port tube structure as can be positioned within or over the expandable structure to permit the retractor to be removed. The tube will retain the incision in the retracted position, and the problems of the prior art resulting from the insertion and removal of multiple differently dimensioned tubes can be avoided.
[0035] The retractor of the invention can be manufactured from various materials, including disposable plastics and metals. Also, the retractor can be made of a stainless steel which can be autoclaved and reused. The retractor and expandable structure can be provided in differing dimensions. In one embodiment, the expandable structure is between about 40 mm and 180 mm long and can expand from a closed position of about 4 mm to 8 mm diameter to an expanded dimension of about 24 mm to 32 mm diameter.
[0036] This invention can be embodied in other forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be had to the following claims rather than the foregoing specification as indicating the scope of the invention.
|
A retractor for surgery includes a retractor body and an elongated and expandable structure attached to the retractor body. The expandable structure, when expanded, has an elongated open interior for the insertion of a portion of a surgical instrument. Drive structure is provided for expanding the expandable structure. A retractor system and method for retracting an incision are also disclosed.
| 0
|
PRIORITY CLAIM
[0001] This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 60/457,823, filed Mar. 25, 2003, the contents of which are incorporated herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to reducing the incidence of collisions involving a vehicle, and in particular, to methods and systems for providing a vehicle operator with information relating to potential collisions.
[0004] 2. Description of the Related Art
[0005] Various vehicular collision avoidance systems have been developed in an effort to reduce accidents and better manage traffic flow. With some conventional systems, cars or trucks are equipped with radar, laser, or other detection systems, that are used to determine the location of the objects. The object location information is provided to the driver, often by depicting the information on a CRT or LCD display using direction vectors or the like. The driver is then theoretically able to use the object location information to determine the positions and relative motions of the objects and to avoid collisions with other vehicles.
[0006] Disadvantageously, the amount of object location-related information can be overwhelming to a driver. Thus, rather than helping the driver avoid a collision, often the driver either ignores the information, or is so distracted by the information that the driver becomes more collision-prone. Further, conventional collision detection displays are often expensive, complex, and can be unreliable in very hot or cold environments.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to methods and systems for providing a vehicle operator with information relating to potential collisions. In contrast to expensive and distracting collision display systems, one embodiment of the present invention utilizes a common vehicle control mechanism, such as a turn signal stalk, to warn the vehicle operator of a potential collision.
[0008] For example, in one embodiment objects in the vicinity of the vehicle are detected using a conventional detection sensor and collision prediction system, such as one based on a radio frequency (RF) radar, a laser radar (LIDAR), or using an imaging camera. By way of illustration, if an object, such as a car, is in an adjacent lane and is directly parallel to, or slightly behind or ahead of the vehicle, the vehicle might collide with the object if the driver attempts to change into that lane. If the detection sensor detects such an object, a collision prediction system inhibits the vehicle's turn signal stalk from being moved by the driver, thereby preventing the driver from signaling a lane change. The driver will thus be warned not to change lanes at this time. Once the detection sensor system determines the danger has passed, the driver will be allowed to appropriately signal a lane change.
[0009] An actuator coupled to the collision prediction system can be used to inhibit the movement of the turn signal stalk. The actuator may be, by way of example, a solenoid, that when activated inserts a plunger or the like into a corresponding bore, slot or notch in the base or mounting plate of the turn signal stalk, thereby preventing the movement of the turn signal stalk.
[0010] In another embodiment, rather than always preventing the turn signal stalk from moving in either an up or down direction when a collision risk exists on either side of the vehicle, the turn signal stalk movement is only inhibited from signaling movement in the direction of the object that is source of the collision risk. In yet another embodiment, rather then preventing movement entirely, the force or pressure that the driver needs to apply to move the turn signal stalk in the “risky” direction will be increased to thereby warn the driver.
[0011] Embodiments of the present invention can be used with other collision warning systems, including without limitations, collision warning displays and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other features of the invention will now be described with reference to the drawings summarized below. These drawings and the associated description are provided to illustrate example preferred embodiments of the invention and are not intended to limit the scope of the invention.
[0013] FIG. 1 illustrates one example embodiment of a vehicle system incorporating an embodiment of the present invention.
[0014] FIG. 2 illustrates an example embodiment of a turn signal movement inhibitor mechanism.
[0015] FIG. 3 illustrates an example embodiment of turn signal movement inhibitor process.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The present invention is directed to methods and systems for warning a vehicle operator of a potential collision. Advantageously, one embodiment of the present invention utilizes a common driver interface device, such as a turn signal control stalk, to warn the driver of a potential collision.
[0017] FIG. 1 illustrates one example of a vehicle system 100 incorporating an embodiment of the present invention. In this example, it will be assumed that the vehicle is a car, though in other embodiments the vehicle can be a truck, bus, boat, or the like. The car 100 includes a detection system 102 used to detect objects in the environment around all or portions of the car. For example, the detection system 102 can detect vehicles in lanes adjacent to the lane that the car 100 is in.
[0018] The detection system 102 can be active and/or passive. If the detection system 102 is active, the detection system 102 emits energy and detects the reflected or returned energy from objects, such as other cars. If the detection system 102 is passive, the detection system 102 does not radiate energy towards other objects, but instead detects objects by monitoring energy, such as infrared energy resulting from heat, emitted by the objects, or by detecting or capturing ambient light reflected by the objects. For example, the detection system 102 can include a radio frequency (RF) radar, a laser radar (LIDAR), an infrared sensor, and/or a camera. The detection system 102 can include multiple sensors, mounted on the front, rear, and/or sides of the vehicle 100 .
[0019] The detection system 102 is coupled to a collision prediction system 104 , which receives detection signals from the detection system 102 . In addition, the collision prediction system 104 receives information regarding vehicle speed and acceleration from conventional vehicle sensors or a vehicle computer. The collision prediction system 104 also receives information on the direction of motion of the car 100 using a compass, GPS or other well-known direction finding devices. Based on the detection signals, the car's speed, acceleration and direction, the collision prediction system 104 determines the physical relationship or placement of the detected objects relative to the car 100 , as well as the speed and acceleration of the car relative to the objects.
[0020] The collision prediction system 104 is coupled to a driver interface, in this example, to a turn signal inhibitor 106 , which is in turn coupled to a turn signal control, such as a turn signal stalk 108 . When the collision prediction system 104 determines that there is an object, such as another car, a truck, motorcycle, stationary object, or the like, in an adjacent lane and parallel to, or slightly behind or ahead of the vehicle, the collision prediction system 104 activates the turn signal inhibitor 106 . The turn signal inhibitor 106 prevents the driver from moving the turn signal stalk 108 in a direction that would signal movement in the direction of the object at issue.
[0021] For example, if another vehicle is adjacent to, and in the lane to the right of the car 100 , the turn signal inhibitor 106 would prevent the driver from pushing the turn signal stalk 108 in the downwards direction, as would normally be done to activate the right turn light to notify others that the driver intends to move into the right lane. Thus, the driver would be warned by his or her inability to so push the turn signal stalk that a collision might result if the driver changes into the right lane at this time. Once the risk of collision has passed, the turn signal inhibitor 106 would allow the turn signal stalk to be moved in the normal manner.
[0022] In another embodiment, rather then preventing movement entirely, the turn signal inhibitor 106 significantly increases the force needed to move the turn signal stalk 108 in the “risky” direction to thereby warn the driver that the car might collide with another object if the driver attempts to change into that lane. However, the driver would still be able to move the stalk 108 , albeit with increased force than would normally be needed. By way of example, a cam requiring a certain amount of force to turn, can engage the turn signal stalk 108 . Similarly, if the driver interface being used to warn the driver of a potential collision is a steering wheel, the force needed to turn the steering wheel in the dangerous direction can be increased using a pressure plate appropriately applied.
[0023] FIG. 2 illustrates an example embodiment of a turn signal movement inhibitor mechanism. The turn signal stalk 108 is mounted to a plate or fixture 202 , which is in turn moveably coupled to a steering wheel column. The fixture 202 includes a curved slot 204 opened on the top and bottom. Two actuators, including plungers or posts 206 , 208 are positioned beneath the slot 204 .
[0024] The posts 206 , 208 may form part of a solenoid or other actuator type, by way of example. A solenoid is an electromagnet tube that can be used to move a piece of metal linearly. In this example, each post 206 , 208 is a cylindrical permanent magnet. The magnetic posts 206 , 208 are moved in and out by changing the direction of the magnetic field in the solenoid. In this example, each post 206 , 208 can be separately raised into the slot 204 and withdrawn from the slot 204 . In other embodiments, rather than using a slot 204 , one or more bores, notches, or other engagement mechanisms can be used. In addition, rather than using posts, or other engagement devices, such as gears, hooks, or the like can be used to selectively and fixedly engage the fixture 202 .
[0025] In the illustrated example, in order to prevent the driver from signaling movement to the right, the movement of the turn signal stalk 108 in the downward direction is prevented by raising the post 206 into the slot 204 . The post 206 will then block the fixture 202 , and hence the turn signal stalk 108 , from rotating downward. Similarly, in order to prevent the driver from signaling movement to the left, the movement of the turn signal stalk 108 in the upward direction is prevented by raising the post 208 into the slot 204 . In order to prevent movement of the turn signal stalk 108 in either the upward direction or the downward direction, both posts 206 , 208 would be raised into the slot 204 . If there is no collision risk, both posts 206 , 208 can be lowered to allow the turn signal stalk 108 to be moved in either the upward direction or the downward direction.
[0026] FIG. 3 illustrates an example embodiment of turn signal movement inhibitor process 300 that can be used with the example systems and apparatuses illustrated in FIGS. 1 and 2 . Beginning at Start state 302 , the process 300 proceeds to state 304 . At 304 a sensor scans the vehicle vicinity for the purposes of determining if there are obstacles which may be potential collision risks. Proceeding to state 306 , a determination is made as to whether there is an obstacle in a lane to the left of, and in the vicinity of the vehicle. If there is such an obstacle, the process 300 proceeds to state 308 , where the turn signal stalk movement is inhibited from activating the vehicle's left turn signal light. Otherwise, the process 300 proceeds directly from state 306 to state 310 . At state 310 , a determination is made as to whether there is an obstacle in a lane to the right of, and in the vicinity of the vehicle. If there is such an obstacle, the process 300 proceeds to state 312 , where the turn signal stalk movement is inhibited from activating the vehicle's right turn signal light, then the process 300 proceeds to End state 314 . Otherwise, the process 300 proceeds directly from state 310 to End state 314 .
[0027] Thus, in contrast to expensive and distracting conventional collision display systems, embodiments of the present invention advantageously utilize a common vehicle control mechanism, such as a turn signal control, to efficiently warn the vehicle operator of a potential collision.
[0028] Various embodiments of the invention have been described above. Although this invention has been described with reference to these specific embodiments, the descriptions are intended to be illustrative of the invention and are not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.
|
An automobile collision warning system includes a sensor system configured to generate a sensor signal corresponding to at least a first sensed object in the vicinity of the automobile. A processor is coupled to the sensor system, wherein the processor is configured to determine if a potential collision risk exists based on the sensor signal and to generate a corresponding collision warning signal. A turn signal inhibition apparatus coupled to the processor configured to inhibit movement of a turn signal stalk in response to the collision warning signal, to thereby warn an automobile operator of the potential collision.
| 1
|
This application incorporates by reference and claims priority to U.S. patent application No. 10/839,864, subsequently issued as U.S. Pat. No. 6,928,059. This application also claims priority to two applications claimed as priority documents in the '864 application (U.S. Provisional Application 60/490,764 filed Jul. 29, 2003 and U.S. Provisional Application 60/468,325 filed May 6, 2003). This application incorporates by reference those two provisional applications. Finally, this application claims priority to co-pending U.S. provisional, application 60/640,278 filed Dec. 31, 2004 for Multipoint Protected Switching Ring and also incorporates that application by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to communication networks, and more particularly, to an apparatus and method for Ethernet equipment in a ring topology.
As Ethernet is deployed in Metro and Access networks, and services are offered on these networks, there is a desire to maintain SONET-like resiliency (i.e. recover from a fault in less than 50 ms). One common means of providing resiliency is with a ring topology. However, Ethernet switches will not work properly if there is a ring or loop in the topology. Protocols such as IEEE 802.1d Spanning Tree Protocol (STP) or IEEE 802.1w Rapid Reconfiguration were invented to detect and remove loops. However, they are slow and cannot achieve path restoral within 50 ms as desired.
To solve this problem, the IEEE is working on 802.17 Resilient Packet Ring (RPR). Others are looking at Multiprotocol Label Switching (MPLS) with Fast Reroute capabilities. Both of these approaches are quite complex. RPR requires a new Media Access Control (MAC) Layer, and MPLS requires extensive signaling. Because of the complexities, these approaches will drive up the cost of the nodes on the ring.
This invention introduces a new way (Protected Switching Ring or “PSR”) of providing protection for Ethernet deployed in a ring topology with resiliency that does not require a new MAC layer, and that can be built using low cost Ethernet chips and methods.
This invention differs from some previous inventions. One of interest is described in U.S. Pat. No. 6,430,151, granted on Aug. 6, 2002. PSR is similar to '151 in that:
Both are based on nodes arranged in a ring topology. Both aim to overcome the limitations of STP. Both describe making or breaking a ring based on the passage or blockage of test messages. Both have two classes of nodes on the ring, one of which is a controller or Master.
Some of the differences between PSR and the teachings of the '151 include:
'151 is composed of bridging nodes that do dynamic layer 2 learning, while PSR is composed of nodes that are configured to switch (add and/or drop) packets based on a VLAN tag. '151 patent has a single redundancy manager (RM), while PSR can support dual redundancy Ring Arbiters (RA). PSR can operate in the presence of a failed RA, thus providing a higher level of availability. The nodes in the '151 patent learn an association between ports and MAC addresses for ring traffic. When the topology changes, the RM of the '151 patent must send a “flush” message to tell the nodes to clear their databases. In contrast, the Ring Relay (“RR”) nodes in PSR always send messages (both data and control) around the ring in both directions, thus removing half of the propagation delay from the recovery time. In this way a flush command is not needed to redirect traffic on the ring, thus reducing the recovery time. '151 patent can cause packets to be duplicated during a restoral as there will be a ring upon restoral. Duplication of packets violates the IEEE 802.3 specifications. The state machines in PSR prevent this. Since nodes in PSR are not performing learning for ring traffic, there is less overhead and a higher packet rate can be sustained for a given amount of processing power.
Another approach to the problem is described in U.S. Pat. No. 4,354,267. The '267 patent describes a set of homogeneous layer 2 devices arranged in a ring. Each node in the '267 patent forwards packets around the ring, and the originator removes the packet.
Some of the differences between PSR and the teachings of the '267 patent include:
'267 patent assumes that data sent that is sent one way around the ring makes it all the way around. In layer 2 systems, each node may pick off packets addressed to it, so this assumption is not valid. '267 patent assumes that each node can repair a fault. See claim 1 in column 10 , starting at line 34, and claim 5 , in column 12 , starting at line 38 . In contrast, PSR concentrates the recovery mechanism in just two nodes.
SUMMARY
Normal 802.3 Ethernet requires a tree topology. If a ring or a loop exists, then packets will be forwarded around the ring indefinitely. STP was created to solve this problem by detecting and breaking any rings. If the ring is broken, then there is no possibility of-packets being propagated forever.
This invention shows how to virtually break the ring such that all nodes can communicate with each other, and how to remove the virtual break when a real failure occurs. This is accomplished by placing intelligent nodes on the ring that work together to virtually break and restore the ring.
In PSR, the nodes communicate between and among themselves to determine when and where a break occurs. The relevant state machines for a preferred embodiment of the present invention are contained within this disclosure.
This application extends and expands on the ability of PSR to handle unidirectional breaks in various ring topologies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of prior art.
FIG. 2 shows an example Protected Switching Ring in the Full Ring mode in normal operation.
FIG. 3 shows an example Protected Switching Ring in the Full Ring mode during a failure.
FIG. 4 shows an example Protected Switching Ring in the High Availability mode in normal operation.
FIG. 5 shows an example Protected Switching Ring in the High Availability mode during a failure.
FIG. 6 shows the state machine for a Ring Arbiter node in the Full Ring mode.
FIG. 7 shows the state machine for a Ring Relay node in the Full Ring mode.
FIG. 8 shows the state machine for the Ring Side of a Ring Arbiter node in the High Availability mode.
FIG. 9 shows the state machine for the Extension Side of a Ring Arbiter node in the High Availability mode.
FIG. 10 illustrates a unidirectional ring break.
FIG. 11 shows the “Dual Homing” embodiment providing User Ports 1140 with redundant links to the existing network.
FIG. 12 shows a “Dual Homing” embodiment providing User Ports 1231 , 1232 , and 1233 with redundant links to the existing network and showing the individual unidirectional links rather than bidirectional links in order to discuss a method of responding to a unidirectional break.
DETAILED DESCRIPTION
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in order to disclose selected embodiments. 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.
Overview
The Protected Switching Ring (PSR) enables building of partial or full ring topologies from low-cost Ethernet equipment, while providing for sub-50 millisecond recovery from equipment or link faults. PSR nodes support the transport of point-to-point port-switched connections across the ring topology. During normal, non-fault operation, one port in the ring will be blocked to user traffic, thus preventing a loop. In the event of a fault in the ring, the blocked port will be unblocked, allowing access to all nodes on the ring.
Two topologies using the present invention are described below. The first topology is the PSR Full Ring (“FR”) configuration that consists of a full ring of PSR nodes. Port-switch connections can be configured between any two subscriber ports on the ring. The second topology is the PSR High-Availability (HA) configuration. This configuration provides a partial-ring extension of a SONET or RPR ring, or a partial-ring addition to existing layer- 2 switching equipment. In either case, a path is engineered through the existing equipment to complete the path for the PSR protocol traffic and user data.
PSR nodes are designated as Ring Arbiters or Relays. Each ring contains two Ring Arbiters. The Ring Arbiters communicate with a “hello” protocol to coordinate the blocking or forwarding of user traffic. In a preferred embodiment, the PSR Ring Arbiter ports take on the role of Master or Slave on the ring according to their relative node priority. In a preferred embodiment the priority could be a unique identifier, such as a MAC address. In a highly preferred embodiment, the priority can be the concatenation of an operator-configurable priority with the MAC address (or other unique identifier) such that the priorities of two nodes would never be equal. In either of these preferred embodiments, the reception of a HELLO with the same priority would indicate a ring with only one arbiter, where that arbiter was receiving its own HELLOs.
In general, during normal fault-free operation of two Ring Arbiters, the Slave Ring Arbiter will block one of its ring ports in order to terminate the ring loop. A ring may contain one or more Relay nodes. The Relay nodes may be distributed in any fashion around the ring, although some benefit is provided by distributing approximately equal numbers of Relays on each “side” of a full-ring configuration.
In addition to the “hello” protocol, each node performs a “discovery” protocol that allows each node to know about all the other nodes on the ring. The discovery protocol is also used to detect persistent ring faults and to generate the associated alarms. Both protocols operate at layer 2 , employing reserved multi-cast MAC addresses.
IP connectivity between all ring nodes is accomplished over a control VLAN used only for that purpose. This allows Telnet and a UDP-based signaling protocol to operate between any nodes on the ring. (An explanation of Telnet is not critical to the understanding of the present invention but Telnet is a terminal emulation program used with TCP/IP networks that allows remote entry of commands that are treated as if input at the network device.) Bridging techniques are used to provide the connectivity for these IP-based applications; all user traffic is transported across the ring using port-switching. As such, all user traffic is point-to-point across the ring; traffic from a subscriber-port/VLAN on one node is connected to a subscriber-port/VLAN on another node.
An additional embodiment of the present invention addresses a partial failure of a network link so that the communication link is lost in only one direction. Yet, another embodiment uses a single arbiter to provide a high reliability connection of user ports to an existing network ring by creating a switching ring with the arbiter and two network ring access points.
Ring Nomenclature
When the PSR is configured, two ports are designated as the ring ports and may be called east and west ports. Also the node type is given to distinguish Ring Arbiter types and Relays (also called Ring Relays or Relay Nodes). The Ring Arbiter type may be High-Availability (HA) or Full-Ring (FR). The two Ring Arbiters on the ring must be of the same type. When speaking of a specific ring port, the partner port refers to the other port of the pair of ring ports on that Ring Arbiter or Ring Relay.
An additional distinction is made in the case of a HA Ring Arbiter. The port of the HA Ring Arbiter connected to the existing SONET or RPR ring is designated the “extension side” (ES) port. This port interfaces with the existing equipment for which we wish to extend a ring segment. The other Ring Arbiter port is referred to as the “ring side” port. It is connected to a string of one or more Ring Relays or directly to the other Ring Arbiter.
HELLO Protocol
Each PSR Ring Arbiter periodically issues a “HELLO” protocol packet out each ring port. In a preferred embodiment each PSR Ring Arbiter issues a “HELLO” protocol packet out each ring port every 10 milliseconds. The packet uses a special multicast MAC address as the destination address. The Relay nodes are configured to have the data plane pass the packet from one ring port to the other, so a Relay node adds only a small amount of delay as the packet moves from one Ring Arbiter to the other. The remote Ring Arbiter node will terminate the packet and send the packet to the control plane. The control plane uses the presence of the new packet and some control information to drive its state machine for the Ring Arbiter ports. The absence of a new HELLO message for 30 milliseconds constitutes a ring timeout. If the timeout persists for 1.5 seconds, a ringfailure is declared and the appropriate alarm is issued.
The significantly longer period used as a trigger for a ring failure keeps a short intermittent problem from being deemed ring failures though the problems may be handled by the declaration of ring timeouts. In one embodiment, the ring failure is detected by loss of Discovery messages, described below. One of skill in the art could implement the ring failure to be based on the absence of HELLO messages rather than Discovery messages. One of skill in the art would appreciate that the HELLOs are not processed at the RR nodes, whereas the Discovery messages are. HELLOs therefore propagate around the ring faster than Discovery messages. A timeout threshold for loss of HELLOs can be set lower than an equivalent threshold for Discovery messages.
A ring timeout causes the state machines to transition a Slave Ring Arbiter port to a FORWARDING state. This response ensures that any loss in connectivity due to a single failure across the ring will only persist for 50 milliseconds or less.
In a preferred embodiment the sequence number in the HELLO PDU is used at the receiving Ring Arbiter to distinguish the arrival of a new HELLO PDU. Those of skill in the art will recognize that other methods could be employed to detect the arrival of a new HELLO PDU. The Relay nodes do not process the HELLO PDUs; they only forward them between ring ports.
Discovery Protocol
The discovery protocol is an optional protocol that can be implemented in order to add functionality. Note since the discovery protocol is not a necessary requirement of the state machines for any of the Ring Arbiters, Protected Switching Rings in accordance with the teachings of the present invention could be implemented without implementing the discovery protocol.
The discovery protocol also uses a special multicast destination MAC, but runs every 500 milliseconds. The discovery PDU is originated by the Ring Arbiters, appended to by intervening Relay nodes, and terminated at the remote Ring Arbiter. As the discovery PDU traverses the path between Ring Arbiters, each node in the path appends its management IP address, egress port for the PDU, and node type to the PDU. Since the discovery messages are flowing in both directions on the ring, each node on the ring can see the path of nodes to each Ring Arbiter on each of its ring ports. For example in FIG. 2 , the Ring port 210 will receive a discovery message on one port directly from the RA 200 and will receive the other discovery message from the RA 225 after that discovery message passes through the ring port 220 . Thus after receiving the two discovery PDUs, each ring port knows the identity of all devices between the ring port and each RA.
Additionally, as each Ring Arbiter constructs the discovery message to send out a ring port, the Ring Arbiter adds the completed node list received at its partner port. This allows every node in the PSR to know all the IP addresses of the nodes in the ring.
In the event of a ring or node failure, the Relay nodes closest to the point of failure will originate the discovery message. In other words, if a relay fails to receive a discovery PDU from its upstream neighbor (due to a link or node failure), then the relay will create and send a discovery PDU in the downstream direction. All downstream nodes will detect that the Ring Arbiter is no longer the originator of the discovery message and declare a fault alarm. If a node either does not receive a Discovery message or receives a Discovery message without a Ring Arbiter as the originator, a ring failure is declared after 1.5 seconds. The fault is cleared when the node receives a Discovery message with a Ring Arbiter as the originator.
PSR Data Plane for User Traffic
User traffic may enter and leave the PSR at any Ring Arbiter or relay node. A PSR connection defines the entry and exit points for a full-duplex flow of user traffic across the ring. This flow is defined by a pair of port/VLAN ID/PSR Node Address tuples. The connection defines a path through the ring between 2 user ports, each residing on a PSR node, configured to carry the user traffic for specific or all VLAN IDs on that port.
As the user traffic enters the ring, a ring tag is added to the packet. The ring tag is a VLAN tag and is unique on the ring. The ring tag defines a given connection between two ring nodes. At the egress node of the PSR connection, the ring tag is removed from the frame before forwarding to the user port. In this way, the VLAN tags present in the user data are transparently transported across the ring. VLAN IDs used on one user port do not interfere with IDs used on another user port.
A PSR node is either an endpoint of a given connection or a transit node for that connection. A PSR node is an endpoint for a connection if one of its user ports is specified in the definition of the given connection. The node is a transit node if neither endpoint of the connection resides on the node. In either case, a switch table used by the data plane is configured on each PSR node to either terminate one end of a given connection or to act as a transit node for that connection. When a node is a transit node for a given connection, the node simply transfers frames from one ring port to the other, based on the ring tag, without modification. When a node is an endpoint node for a given connection, the data plane directs the data arriving on a ring port to the correct user port and removes the ring tag. Conversely, the node's data plane directs user packets from the given user port with the given VLAN ID to the ring ports, adding the correct ring tag in the process.
PSR Control Plane for Control Traffic
A PSR requires a mechanism to transport HELLO PDUs, discovery PDUs, and IP traffic for ring control applications between PSR nodes. While user traffic transport is transported using switching techniques, in a preferred embodiment the control functions are transported using bridging techniques. By using bridging techniques, full PSR node control connectivity is attained with all nodes appearing on the same IP subnet. This makes configuration much simpler.
One ring tag is reserved for PSR control traffic. The data plane uses learning procedures and forwarding table lookups to direct control traffic to the correct PSR node. Note that the use of learning procedures and forwarding table lookups for the direct control traffic imposes an overhead burden that is orders of magnitude smaller than the overhead needed to use learning techniques for user data traffic. In the preferred embodiment the HELLO and discovery messages use known multicast MAC addresses and thus do not add additional learned database entries to be forwarded. Flushing is not needed for the control traffic upon failure, recovery, or reconfiguration of the ring, as the new port entries are learned from bidirectional traffic after a short period of time.
While the use of bridging for control traffic is preferred, it is not required in order to implement the present invention. The present invention could be implemented to use switching techniques for data packets and some or all types of control traffic. Care must be taken in creating this variation that the control traffic described in this application as passing when data packets are blocked, must be allowed to pass.
Example Recovery for Full Ring
Fault Detection
FIG. 3 shows a full ring where the link 1325 fails between nodes 310 and 320 . This means that RA nodes 300 and 325 are unable to communicate with each other via the left hand side of the ring. Prior to the failure, assume that RA node 325 , the Slave Ring Arbiter, is blocking traffic on link 1330 (thus no counterclockwise communication on 1330 ) and forwarding traffic on link 1335 . Also, any user traffic arriving on link 1330 is discarded. So clockwise traffic on 1330 is discarded at the 1330 side of RA 325 . Communications to subscriber ports connected to RA 325 reach those ports through counterclockwise communication over link 1335 to RA 325 .
Assuming RA node 300 was the Master Ring Arbiter, when RA node 325 detects the loss of communication; RA node 325 will start forwarding traffic to the right hand side of the ring onto link 1330 and accepting user traffic arriving on link 1330 and relaying the traffic to link 1335 and to the subscriber ports of RA 325 . This will restore communications between all of the nodes on the ring. At this point, RA 325 is forwarding traffic on both ring ports. The ring port that is facing link 1335 is in MASTER FORWARDING state, and the ring port that is facing link 1330 is in SLAVE FORWARDING state.
Link Restoral
When link 1325 is restored, RA node 325 needs to block one of its ring ports to prevent a loop in the ring. When RA node 325 receives the first HELLO on link 1335 (due to the restoration of link 1325 ), RA node 325 will see that the partner port to the port that is facing link 1335 is in SLAVE FORWARDING state. RA node 325 will move the port that is facing link 1335 to the BLOCKING state. Assuming that the Ring ports of nodes 310 and 320 connected to link 1325 went to an OPER DOWN state during the failure, the TIMING state in the relay nodes 310 and 320 will prevent forwarding of traffic until the Slave Ring Arbiter has time to switch from MASTER FORWARDING to BLOCKING on the 325 side of the Ring Arbiter. OPER DOWN is an indication from the physical or transport layer that a link is not operational. It is normally based on the detection of loss or corruption of the incoming electrical or optical signal.
The advance to the TIMING state is triggered by the reception of a HELLO message. This TIMING state delay in the resumption of operation of relay nodes 310 and 320 prevents duplicate packets from reaching a given destination when the failed link is restored. To illustrate the value of this delay in the Ring Relay ports, consider a message coming to Ring Relay 305 to a subscriber port connected with Ring Relay 310 just before link 1325 is restored. Ring Relay 305 operating normally will send the same message onto link 1300 and link 1320 . The message traveling counterclockwise reaches Ring Relay 310 in a conventional way. The message traveling clockwise to Ring Relay 310 will pass through Ring Arbiter 325 onto link 1335 as the west Port is operating in MASTER FORWARDING. When link 1325 is restored, there is a path for a duplicate message to cross link 1325 to Ring Relay 310 . This potential is eliminated if the Ring Relay ports undergo a suitable delay between receipt of the first HELLO and the ultimate state of FORWARDING. Note that the HELLO messages from Ring Arbiter 300 to Ring Arbiter 325 and from Ring Arbiter 325 to Ring Arbiter 300 will pass over link 1325 as soon as it is restored as the HELLO messages are not blocked at any port in any state.
The preferred embodiments disclose using a timing delay to ensure that a port progressing from OPER DOWN to operational delays sending data packets long enough for the Slave arbiter to impose a virtual break. One of skill in the art will recognize that the use of the timer could be replaced by a control signal sent by the Slave arbiter after it has successfully imposed the virtual break. In either case, the port does not go to fully operational until after the virtual break has been imposed to preclude the creation of a ring for data packets.
Example Recovery for HA Ring
Fault Detection
FIG. 4 shows a HA ring under normal fault-free operation. The ES Slave port 1440 is in the BLOCKING state to prevent a ring loop. FIG. 5 shows a HA ring where the link 1520 , between nodes 510 and 520 , fails. As for the full ring case, the bidirectional failure of link 1520 means that the Ring Arbiter nodes 500 and 530 are unable to communicate over the left side (Ring Side) portion of the HA ring. Assuming Ring Arbiter node 530 is the Slave, its ES port (the facing link 1540 ) would be un-blocked when the failure is detected. Fault detection and subsequent un-blocking of the Slave Ring Arbiter port is fundamentally the same as for the full ring case described above.
Link Restoral
In a preferred embodiment, the HA ring favors the Ring Side once the fault is removed. Instead of leaving the Slave Ring Arbiter ES port (the port facing link 1540 ) in the forwarding state and blocking the Ring Side port (the port facing link 1530 ), the HA Slave Ring Arbiter 530 always returns to a FORWARDING state on the Ring Side segment and blocks the ES port.
The Ring Side segment of the HA ring is favored in order to minimize HA ring traffic on the existing SONET or RPR ring as this will cut some of the user traffic on the SONET ring segment between the Ring Access Equipment as one direction will be blocked (thus counterclockwise traffic from port 1440 will be blocked while clockwise traffic from 1400 will continue to travel on the SONET Ring.
Nomenclature for State Diagrams
In the following descriptions, “isMaster” is based on the last received HELLO. If no HELLO was ever received on the port, then isMaster is based on the partner's last HELLO. If no HELLOs have ever been received by either port, then isMaster is “true”. The Boolean variable “isSlave” is the logical negation of“isMaster”.
The term “PartnerHelloTimeout” indicates that the partner port's age timer has timed out. The designation “RxHello<Node” means a HELLO message has been received whose priority is less than that of the receiving node. This event would cause the receiving node to consider itself a Master.
Full Ring Mode—Ring Arbiter
FIG. 6 shows the state diagram for a RA node. Each of the two ports on an RA node runs a copy of this state machine.
Description of States
The state machine of FIG. 6 has the following states.
TABLE A Number State Description 600 PORT DOWN The port is operationally down or has just been initialized. Entered from any state. 610 BLOCKING The node is sending HELLOs, but not forwarding data traffic. 620 SLAVE TIMING Node knows that it is a Slave, but port is waiting for a timer to expire before moving to a forwarding state. 630 MASTER TIMING Node knows that it is a Master, but port is waiting for a timer to expire before moving to a forwarding state. 640 SLAVE The port on a Slave Node is forwarding packets FORWARDING 650 MASTER The port on a Master Node is forwarding packets FORWARDING
Description of State Transitions
The table below describes the transitions of the state machine shown in FIG. 6 .
Note the fd timer reference below runs using a time that is a small fraction of the time used for the age timers in the RA and Relay nodes. This ensures that the relays are timed for a period long enough after the expiration of the fd timer for the loop to be broken. For example, one embodiment uses a 10 millisecond timer for the RA and Relay nodes and the fd timer at just one “tick” (a single 10 millisecond delay). This 10 millisecond interval is a small fraction of the 30 millisecond interval used to detect a ring timeout when a new HELLO message does not arrive within that interval.
Note that the state machine for ring arbiters in the preferred embodiment does not wait indefinitely to see a HELLO as long as the ports of the ring arbiter are operationally UP. The goal is to let the parts of the network ring operate even if other portions of the network ring cannot operate.
TABLE B
Num
Event
Action
1610
port operationally down OR init
block user traffic,
cancel all timers
1615
port operationally up
start age timer
1620
age timer expires OR RxHello < Node
start fd timer
1625
fd timer expires
restart age timer,
forward user traffic
1630
RxHello > Node
start fd timer
1635
fd timer expires AND partner not SLAVE
restart age timer,
FORWARD
forward user traffic
1640
age timer expires OR RxHello < Node
restart fd, age timer
1645
RxHello > Node
restart fd timer
1650
Age timer expires OR RxHello < Node
restart age timer
1655
RxHello > Node AND partner not SLAVE
restart age timer
FORWARD
1660
RxHello > Node AND partner SLAVE
restart age timer
FORWARD
The following table shows the complete state transitions for the Full-Ring Arbiter as shown in FIG. 6 .
TABLE C
Current State
PORT
SLAVE
MASTER
SLAVE
MASTER
DOWN
BLOCKED
TIMING
TIMING
FORWARDING
FORWARDING
Event
600
610
620
630
640
650
Oper Down
N/A
PORT DOWN
PORT DOWN
PORT DOWN
PORT DOWN
PORT DOWN
Oper Up
BLOCKED
N/A
N/A
N/A
N/A
N/A
Age Timer
N/A
MASTER
MASTER
MASTER
MASTER
MASTER
Expires
TIMING
TIMING
TIMING
FORWARDING
FORWARDING
fd Timer Expires
N/A
N/A
N/A
MASTER
N/A
N/A
FORWARDING
fd timer Expires
N/A
N/A
SLAVE
N/A
N/A
N/A
AND Partner
TIMING
SLAVE
FORWARDING
fd Timer Expires
N/A
N/A
SLAVE
N/A
N/A
N/A
AND Partner not
FORWARDING
SLAVE
FORWARDING
RxHello < Node
N/A
MASTER
MASTER
MASTER
MASTER
MASTER
TIMING
TIMING
TIMING
FORWARDING
FORWARDING
RxHello ≧ Node
N/A
SLAVE
SLAVE
SLAVE
N/A
N/A
TIMING
TIMING
TIMING
RxHello ≧ Node
N/A
N/A
N/A
N/A
N/A
BLOCKED
AND Partner
SLAVE
FORWARDING
RxHello ≧ Node
N/A
N/A
N/A
N/A
SLAVE
SLAVE
AND Partner not
FORWARDING
FORWARDING
SLAVE
FORWARDING
In a preferred embodiment, every 10 milliseconds, the two ports are checked in the same order. The combination of variations in when the HELLOs were generated plus transit delays may cause one HELLO on one port to arrive before the other HELLO on the other port. In any case, since one port is checked before the other then the other, it always appears as though one HELLO arrives before the other. The order that the ports are checked does affect which Slave port is set to BLOCKING on the full ring.
One of skill in the art will recognize that any embodiment that does not check one port before the other would need to address the case of two HELLOs arriving essentially simultaneously at the two ports.
TABLE D Time Port A Input State Change Port B Input State Change 1 Port Down Port up 1615 to Port Down Port up 1615 to Blocking Blocking HELLOs generated by other RA and sent towards ports A and B of this RA. One HELLO arrives slightly before the other. 2 Blocking RxHello > node 1630 to Slave Blocking Timing 3 Slave Timing Blocking RxHello > node 1630 to Slave Timing 4 Slave Timing fd timer 1635 to Slave Timing expires and SLAVE partner not FORWARD SLAVE FORWARD 5 Slave forward Slave Timing [cannot advance to Slave Forward as partner is in Slave Forward] 6 Link breaks 7 Slave Forward Link breaks, 1650 to Master Slave Timing age timer Forwarding expires 8 Master Slave Timing fd timer 1635 to Forward expires and SLAVE partner not FORWARD SLAVE FORWARD 9 Master Slave Forward Forward 10 Link Restored 11 Master RxHello > Node 1660 to Slave Forward Forward and Blocking partner Slave Forward 12 Blocking RxHello > Node 1630 to Slave Slave Forward Timing This continues until a port goes down, a link goes down, or the node number of the other RA changes to become less than Node (normally this would take a reconfiguration from the operator or the substitution of another RA unit).
Full Ring Mode—Ring Relay
FIG. 7 shows the state machine for a Ring Relay node.
Description of States
The state machine of FIG. 7 has the following states.
TABLE E Number State Description 700 PORT DOWN The port is operationally down or has just been initialized. Entered from any state on an indication of the port going down due to a loss of signal or other similar alarm. 710 AWAITING Port is operationally up, but no HELLO HELLO has been received 720 TIMING The port is waiting for the fd timer to expire 730 FORWARDING Normal forwarding.
Description of State Transitions
The table below describes the transitions of the state machine shown in FIG. 7 .
TABLE F Number Event Action 1710 port operationally down block user traffic, OR init cancel all timers 1715 port operationally up start age timer 1720 age timer expires OR RxHello start fd timer 1725 fd timer expires forward user traffic
High Availability Mode—Ring Arbiter—Ring Side
FIG. 8 shows the state machine for the Ring Sides (RS) of a Ring Arbiter in HA mode.
Description of States
The state machine of FIG. 8 has the following states.
TABLE G Number State Description 800 PORT DOWN The port is operationally down or has just been initialized. Entered from any state. 810 BLOCKING The port is sending HELLOs, but is not forwarding data traffic. 820 SLAVE FORWARDING The port on a Slave Node is forwarding packets 830 MASTER The port on a Master Node is FORWARDING forwarding packets
Description of State Transitions
The table below describes the transitions of the state machine shown in FIG. 8 .
TABLE H Number Event Action 1810 port operationally down OR init block user traffic, cancel age timer 1815 port operationally up start age timer 1820 (age timer expires AND isMaster) Forward user traffic OR RxHello < Node 1825 (age timer expires AND isSlave) OR Forward user traffic RxHello > Node 1830 RxHello < Node No action 1835 RxHello > Node No action
High Availability Mode—Ring Arbiter—Extension Side
FIG. 9 shows the state machine for the Extension Side (ES) of a Ring Arbiter in HA mode.
Description of States
The state machine of FIG. 9 has the following states.
TABLE I Number State Description 900 PORT DOWN The port is operationally down or has just been initialized. Entered from any state. 910 BLOCKING The node is sending HELLOs, but not forwarding data traffic. 920 SLAVE FORWARDING The port on a Slave Node is forwarding packets 930 MASTER The port on a Master Node is FORWARDING forwarding packets
Description of State Transitions
The table below describes the transitions of the state machine shown in FIG. 9 .
TABLE J
Number
Event
Action
1910
port operationally down OR init
block user traffic, cancel
age timer
1915
port operationally up
start age timer
1920
(age timer expires AND isMaster)
forward user traffic
OR RxHello < Node
1925
(age timer expires AND isSlave)
forward user traffic
1930
RxHello < Node
continue forwarding user
traffic
1935
RxHello > Node AND
continue forwarding user
PartnerHelloTimeout
traffic
1940
RxHello > Node AND NOT
block user traffic, start
PartnerHelloTimeout
age timer
1945
RxHello > Node AND NOT
block user traffic, start
PartnerHelloTimeout
age timer
As shown in the sequence of events reported in the table below, the RS ports of the Arbiters are always forwarding, unless the ports are OPER DOWN. The point of interest is the state of the ES port of the Slave Arbiter. In essence, the ES Slave port is FORWARDING if there is a HELLO timeout on either the RS or ES.
TABLE K
Port Status
(before trigger)
500
500
530
530
TIME
RS
ES
RS
ES
Trigger
Reaction
1
800
900
800
900
500 initialized
500 RS goes Blocking,
500 ES Goes to Blocking
2
810
910
800
900
530 initialized
530 RS goes Blocking,
530 ES Goes to Blocking
3
810
910
810
910
500 receives HELLO from 530
500 RS state change 1820 to
and RxHello < node
Master Forwarding
500 ES state change 1920 to
Master Forwarding
4
810
910
830
930
530 received HELLO from 500
530 RS state change 1825 to Slave
and RxHello > node
Forwarding
530 ES does not leave Blocking
unless RS or ES has HELLO
timeout
5
820
910
830
930
Continues operation with the
virtual break in the HA ring at the
ES of the Slave (RA 500).
6
820
910
830
930
Break in link 1520 (ring side)
7
820
910
830
930
RxHellos stop coming on RS
500 RS no change
530 ES state change 1925 to Slave
Forwarding
8
820
920
830
930
All four ports forward traffic while
there is a physical break
9
820
920
830
930
Break fixed
10
820
920
830
930
RxHello received at 530 RS and > node
530 ES state change 1945 to
blocking
11
820
920
830
930
Continues operation with virtual
break.
12
820
910
830
930
Link break ES
13
820
910
830
930
HELLOs stop on ES side of both
530 ES notes that its age timer
RA units
expires and it isSlave and has state
change 1925 to Slave forwarding
14
820
920
830
930
All four ports forward traffic while
there is a physical break
15
820
920
830
930
Break fixed
16
820
920
830
930
530 ES receives RxHellos > node
530 ES moves along state
and not
transition 1945 to Blocking
PartnerHelloTimeout
17
820
910
830
930
Until next break, port down, or
switch in node numbers sufficient
to change Master/Slave
relationship.
ALTERNATIVE EMBODIMENTS
Unidirectional OPER DOWN Break on Full or High-Availability Rings
The control system described above assumes that a break in a network ring will be a bidirectional break as it connects both the clockwise and counterclockwise virtual breaks upon failure to receive a HELLO. This bidirectional response could cause a loop in the event of a unidirectional failure.
FIG. 10 , adds additional detail to the drawing shown in FIG. 2 . More specifically, the links are shown in their unidirectional components rather than as bidirectional links.
For example, when the network ring is fully operational, and the Slave Arbiter has imposed a virtual break on the west ring port, Master Arbiter 1000 can receive HELLOs from Slave Arbiter 1025 via link 11037 , Relay 1020 , link 11027 , Relay 1010 , and link 11012 . Likewise, Slave Arbiter 1025 can receive HELLOs from Master Arbiter 1000 via link 11010 , Relay 1010 , link 11025 , Relay 1020 , and link 11035 .
If link 11027 was cut but link 11025 was left in service, then the west port on Master Arbiter 1000 would soon stop receiving HELLOs from Slave Arbiter 1025 , while west port of Slave Arbiter 1025 continued to receive HELLOs from Master Arbiter 1000 . In the previously described embodiment, this unidirectional cut at link 11027 would not trigger the Slave Arbiter 1025 to unblock as it continues to receive HELLOs from Master Arbiter 1000 as these HELLOs can still travel across intact link 11025 . Thus Ring Relay 1020 as well as connected subscriber ports 1045 would be unable to send data to any node on the ring as Slave Arbiter 1025 is still blocking data. (Note: as link 11025 is intact, Ring Relay 1020 and subscriber ports 1045 can still receive data packets)
One alternative embodiment is to react to a port going to an OPER DOWN state by stopping the transmission of HELLOs and all data from that port in the opposite direction, effectively creating an imposed unidirectional break in the other direction. Hence when ring relay 1010 observes an OPER DOWN associated with link 11027 , Ring Relay 1010 would stop sending HELLOs and all data on link 11025 . After Slave Arbiter 1025 fails to receive HELLOs in an allotted time, the Slave Arbiter 1025 would remove the virtual break on its west side to allow data traffic from link 11035 to proceed towards link 11030 or the user ports 1060 and to allow traffic from link 11032 or user ports 1060 to proceed onto link 11037 , thus putting Ring Relay 1020 back into data communication with the other ring nodes.
Another Solution to Unidirectional Breaks on Full or High-Availability Rings
In some cases, the OPER state of a ring port may not be DOWN, event though a unidirectional failure is present. One example of this type of situation occurs when a leased TDM link (such as a T 1 , DS3, or OC-n) is interrupted by the service provider such that there is no physical layer fault. Likewise, a Gigabit Ethernet link with auto-negotiation disabled may not report link failure in the case of a unidirectional break. In either case, no data can traverse the link in one direction.
A more comprehensive solution to the risk of a unidirectional break is one that reacts to either an OPER DOWN or an extended break in the receipt of HELLO messages. In this embodiment a Ring Relay would respond to either an OPER DOWN on a receiver or a gap of more than a set time period without receiving a HELLO on a particular receiver to declare a link failure. For example, a gap of 30 milliseconds (three ticks of a ten millisecond clock) is used in one embodiment as the indication of too long a period without a HELLO on a receiver link.
After detecting either type of failure, a Ring Relay does the following:
Creates a bidirectional break by blocking data on the outgoing link on the same port as the receiver link deemed to have failed. (Note that the Ring Relay does not know whether the break discerned on the receiver link is a bidirectional break or a unidirectional break but handles all breaks as a unidirectional break. Thus the Ring Relay may impose a redundant break on a broken transmitter side link but this is harmless.)
Creates a break at the receive link that is deemed to have failed. This seems redundant but imposing a break on a broken link allows the imposed break to remain for a period after the real break is removed so that the Slave Arbiter has a chance to re-impose a virtual break before the imposed break is removed at the Ring Relay.
Sends flagged HELLO protocol packets on the outgoing link on the same port as the receiver link deemed to have failed. These flagged HELLO protocol packets serve two purposes. They serve as HELLO protocol packets so that other nodes do not experience (or maintain) the state of a HELLO timeout. These flagged HELLO protocol packets are distinguishable from normal Arbiter generated protocol packets and thus convey to the Slave Arbiter that a bidirectional break is being imposed and thus the Slave Arbiter needs to remove the virtual break.
Blocks HELLO messages from the transmit link on the partner port relative to the port with the detected failure on the receive link. Sends flagged HELLO messages on the transmit link on the partner port. Note that as Ring Relays are provided with generic control logic which does not need to be configured to indicate the direction of the Slave Arbiter, the Ring Relay operates without needing to know which direction is the Slave Arbiter and which direction is the Master Arbiter. Thus, upon detecting a failure, the Ring Relay sends flagged HELLO messages in both directions to ensure that the Slave Arbiter receives the indication that the Slave Arbiter needs to remove the virtual break.
In the example using FIG. 10 , when Ring Relay node 1010 experiences a HELLO timeout with no OPER DOWN on receiver link 11027 , Ring Relay node 1010 will block all user traffic onto link 11025 and from link 11027 to thus make a what might be a unidirectional break on 11027 into a bidirectional break. The Ring Relay 1010 will send out flagged HELLO messages on both link 11012 l and onto link 11025 with the “regenerate” flag set (the normal HELLO messages from Master Arbiter 1000 will be blocked at 1010 so only the flagged HELLO messages are placed onto transmit link 11025 ). The Slave Arbiter 1025 , will see the HELLO messages with the “regenerate” flag set, and unblock whichever side is currently blocked (east side port or west side port).
Since each node is regenerating upstream and downstream HELLO messages in the event of an upstream HELLO timeout, a node may be assured that it is directly attached to the segment with the unidirectional failure into its receiver if it experiences a persistent HELLO timeout. The node directly attached to the segment that is experiencing such a receiver failure is responsible for turning the unidirectional break into a bidirectional break and maintaining that break until the failure is cleared and the Slave Arbiter has been given time to re-impose the virtual break.
Note that each Ring Relay downstream from the node adjacent to the break may briefly experience a HELLO timeout before it receives the flagged HELLOs. During the brief period the downstream nodes may also impose a break. However, each node will remove the break once it sees the flagged HELLOs. Also, note that HELLO timeout period (30 ms) is longer than the maximum time to remove the break (10 ms), ensuring that excess virtual breaks do not propagate upstream during this brief period. To illustrate this point, if a unidirectional break that did not generate an OPER DOWN was incurred on link 11010 , then after 30 milliseconds, both Ring Relay 1010 and Ring Relay 1020 will note the absence of HELLO messages and take corrective action to impose a break and send flagged HELLO messages. However, when Ring Relay closest to the real failure (in this case Ring Relay 1010 ) sends out flagged HELLO protocol packets on link 11025 , these HELLO messages will be received by Ring Relay 1020 which will stop imposing a break on links 11027 and 11025 .
When a Ring Relay comes back after an OPER DOWN or a HELLO timeout failure, the Ring Relay resumes transmissions of normal HELLO messages first then there is an imposed delay (fd as discussed above) before removing the virtual breaks for data on both the receiver link deemed to have failed and the transmit link on that same port to avoid having a temporary loop before the Slave Arbiter has a chance to impose a virtual break.
The Master Arbiter must be modified to incorporate rules used by the Ring Relays as the Master Arbiter acts much like a Ring Relay with respect to reacting to a lack of HELLOs or an OPER DOWN on a receiver link for the Master Arbiter. More specifically, the Master Arbiter must be adapted to suppress transmission of user data and set the regenerate bit on transmitted HELLOs on a port that is experiencing HELLO timeouts or an OPER DOWN. In this case the Master Arbiter may surmise that the unidirectional break is present on its directly attached segment. If flagged or original HELLOs are received, the Master Arbiter transmits HELLOs with no regenerate flag set and passes user data as usual after a period of delay sufficient to allow the Slave Arbiter time to reinsert the virtual break and thus avoid a temporary loop. A Master Arbiter modified to act like a Ring Relay would respond to a failure by sending flagged HELLOs out both ports.
One minor difference between a Master Arbiter and a Ring Relay is that the Master Arbiter knows that the Slave Arbiter is both on the east side and on the west side of the Master Arbiter. In contrast as a Ring Relay does not ordinarily send HELLO messages through a Master Arbiter. the Slave Arbiter is only to one side of the Ring Relay, not both. In a preferred embodiment the Master Arbiter is configured to transmit flagged HELLOs just on the port with the receive link deemed to have failed. The partner port continues to send normal HELLOs
The following example uses the network loop shown in FIG. 10 but assumes that all links are initially working properly. When link 11012 fails through either an OPER DOWN or a problem that causes Master Arbiter 1000 to note that the west port is not receiving HELLOs, a Master Arbiter configured to send flagged HELLOs on link 11010 but continues to send normal HELLO messages on its partner port may not actually provide notice to Slave Arbiter 1025 of a problem as there may have been a bidirectional break rendering link 11010 inoperative. More specifically. when a bidirectional failure is experienced at links 11012 and 11010 , then the Master Arbiter would impose a virtual break on the west port (as it does not know whether the break is a unidirectional break link 11012 l only or a bidirectional break as generally it is not possible to perceive a break on a transmit link) but continue to send flagged HELLOs on transmit port 11010 . As these flagged HELLOs cannot reach Ring Relay node 1010 across broken link 11010 , Ring Relay node 1010 will also note the gap in HELLOs and will take steps to impose a virtual break on links 11012 and 11010 . When Ring Relay 1010 responds to the gap in HELLOs or OPER DOWN a portion of the response will include the sending of flagged HELLO protocol packets on link 11025 . These flagged HELLO protocol packets from Ring Relay 1010 ultimately reach the Slave Arbiter and trigger the removal of the virtual break at a port connected to Slave Arbiter 1025 .
The Slave Arbiter has two tasks. The first task is like other nodes, it converts sensed link failures (either OPER DOWN or HELLO Timeout) as a potential unidirectional break and imposes a break on the transmit link on the port with the perceived failure of its receive link. The Slave Arbiter has the second task of removing the imposed virtual break that is used to avoid looping after another bidirectional break exists in the network loop.
The methods of implementing these two tasks could be done in several different ways depending on a design choice to use common instructions for both Master Arbiter and Slave Arbiter in their response to what may be a unidirectional failure. Using common instructions for this aspect of operation is potentially useful as in the preferred embodiment an Arbiter contains the instruction set necessary to act as either a Master Arbiter or a Slave Arbiter.
Assuming that the design choice is made to use common instructions with the Master Arbiter, the sequence of events for a break detected by a Slave Arbiter is illustrated by the following examples using the components shown in FIG. 10 . In each example, the example starts with all links functioning (including link 11027 ) and with a virtual break imposed on the east port of Slave Arbiter 1025 (links 11030 and 11032 passing HELLOs but not user data).
First Case—Break on Incoming Link on Port Away from Virtual Break
Link 11035 experiences a failure that does not lead to an OPER DOWN but does lead to a HELLO timeout noted at Slave Arbiter 1025 . The Slave Arbiter acts like any other node to impose a bidirectional break at the failed port. The Slave Arbiter imposes a break on links 11035 and 11037 . If the Slave Arbiter is using common instructions with the Master Arbiter mode, then the Slave Arbiter would send flagged HELLOs instead of HELLOs on link 11037 despite the fact that this flagged HELLO is only of significance to the Slave Arbiter.
The recovery in this first case would start when the problem with link 11035 is corrected and normal HELLOs from Master Arbiter 1000 are again received at the Slave Arbiter on link 11035 . A Slave Arbiter using common instructions with a Master Arbiter would stop sending flagged HELLOs and would resume sending normal HELLOs. The Slave Arbiter would re-impose the virtual break so the virtual break is in place after the imposed bidirectional break is removed. After a delay of fd, the Slave Arbiter would remove the imposed bidirectional break.
Second Case—Bidirectional Break between Ring Nodes
Link 11025 experiences a failure that does not lead to an OPER DOWN but does lead to a HELLO timeout noted at Ring Relay node 1020 . The problem is actually bidirectional so that Ring Relay 1010 also experiences a HELLO timeout on link 11027 . As described above, Ring Relay node 1020 would create a bidirectional break on the port experiencing the receiver failure so that no data passes through that port but sends out flagged HELLOs onto link 11027 and listens for HELLOs on link 11025 . Ring Relay 1020 sends out flagged HELLOs on both link 1027 and link 11035 .
As Ring Relay 1010 is also experiencing a HELLO timeout on link 11027 , this Ring Relay imposes a bidirectional break on links 11027 and 11025 and sends out flagged HELLOs on links 11025 and link 11012 .
The Slave Arbiter would start the process described in the First Case of imposing a bidirectional break on links 11035 and 11037 in addition to the existing virtual break on the east port since the Slave Arbiter would have no way of knowing if the problem was in the link adjacent to the Slave Arbiter or upstream from there. The flagged HELLOs sent on link 11035 are received at Slave Arbiter 1025 which then removes the virtual break on links 11030 and 11032 as the receipt of a flagged HELLO indicates that a bidirectional break is being imposed by another node on the network ring. After a delay of fd, the Slave Arbiter would remove the imposed bidirectional break on links 11037 and 11035 . After this sequence of events the network ring would have an imposed bidirectional break on links 11025 and 11027 at Ring Relay 1020 and again at Ring Relay 1010 .
When the problem on links 11025 and 11027 are resolved, Ring Relay nodes 1010 and 1020 will stop sending flagged HELLO and then after a delay remove the imposed bidirectional breaks on links 11027 and 11025 . Slave Arbiter 1025 upon receipt of a normal HELLO from Master Arbiter 1000 will impose a virtual break on the port in Master Forwarding mode which in this situation should be the east port (links 11030 and 11032 ).
Third Case—Break on Outgoing Link on Port away from Virtual Break.
Link 11037 experiences a failure that does not lead to an OPER DOWN but does lead to a HELLO timeout noted at Ring Relay 1020 . As noted above, Ring Relay 1020 will impose a bidirectional break on links 11037 and 11035 and start sending flagged HELLOs on links 11035 and 11027 . (As the temporary imposition of additional bidirectional breaks by downstream nodes such as Ring Relay 1010 and Master Arbiter 1000 has already been explained above, it will be omitted in subsequent discussions). The Slave Arbiter will remove the virtual break at links 11030 and 11032 after receiving a flagged HELLO on link 11035 . When the problem with link 11037 is resolved, the Ring Relay 1020 will stop sending flagged HELLOs and will allow normal HELLOs originating from Master Arbiter 1000 to reach the Slave Arbiter 1025 on link 11035 . The response to the receipt of normal HELLOs instead of flagged HELLOs by the Slave Arbiter 1025 is to re-impose the virtual break on links 11030 and 11032 .
Fourth Case—Break on Incoming Link at Virtual Break
Link 11030 experiences a failure that does not lead to an OPER DOWN but does lead to HELLO timeout at Slave Arbiter 1025 . Although link 11030 has an imposed virtual break for data traffic. HELLOs are received at Slave Arbiter 1025 and the lack of HELLOs triggers a response. Functionally, a bidirectional break is imposed on links 11030 and 11032 (including the transmission of flagged HELLOs if the Slave Arbiter is configured to use the same code as the Master Arbiter), then after a short delay, the virtual break is removed from links 11030 and 11032 . One of skill in the art can recognize that the logic could be modified to simply leave the virtual break in place but note that the reason for the break has changed from the Slave Arbiter needing to impose a virtual break to the need to convert a potential unidirectional break into a bidirectional break.
After the problem on link 11032 is corrected, the Slave Arbiter receives normal HELLO messages from Master Arbiter 1000 and reverses the process by first imposing a virtual break on links 11030 and 11032 and then removing the imposed bidirectional break on links 11030 and 11032 . Again, one of ordinary skill in the art can see that this can be done by changing the reason for the break without adding and removing breaks.
Fifth Case—Break on Outgoing Link at Virtual Break
Link 11030 experiences a failure that does not lead to an OPER DOWN but does lead to a HELLO timeout at Ring Relay 1015 (and as discussed above, temporarily at Ring Relay 1005 and Master Arbiter 1000 ). To distinguish this example from the last case, assume that the problem is unidirectional such that link 11032 is operating properly and Slave Arbiter 1025 is receiving HELLOs on link 11032 . Ring Relay 1015 imposes a bidirectional break on links 11030 and 11032 and starts to send flagged HELLOs on links 11032 and 11020 . This bidirectional break imposed by Ring Relay 1015 is redundant to the virtual break already imposed by the Slave Arbiter as both block data but not HELLOs. The receipt of a flagged HELLO at link 11032 of Slave Arbiter 1025 indicates that another node has imposed a bidirectional break so the virtual break is removed from 11030 and 11032 by the Slave Arbiter. While the removal of a virtual break from links 11030 and 11032 has no practical effect, one can appreciate that the Slave Arbiter does not know whether the flagged HELLOs are coming from an immediately adjacent node (Ring Relay 1015 ) or a remote node (such as Ring Relay 1005 or Master Arbiter 1000 ). If the flagged HELLOs were coming from a remote node, then removal of the virtual break would make the adjacent node (in this case Ring Relay 1015 ) connected for data communication with the rest of the ring.
When the problem with link 11030 is corrected, Ring Relay 1015 will receive normal HELLO messages from Slave Arbiter 1025 . The receipt of normal HELLO messages will cause the Ring Relay to stop sending flagged HELLO messages. The receipt of a normal HELLO message at link 11032 of Slave Arbiter 1025 will cause the Slave Arbiter to re-impose a virtual break on links 11030 and 11032 . After a short delay, Ring Relay 1015 removes the bidirectional break from links 11030 and 11032 .
Separation of HELLO Message and Imposed Break Message
One of ordinary skill in the art can see that a flagged HELLO protocol packet as discussed above actually serves two purposes. First purpose is to provide a HELLO message to downstream nodes so that the HELLO timers do not see a gap in HELLOs. The second purpose is to convey a message to the Slave Arbiter that another node has imposed a bidirectional break so the Slave Arbiter can remove the virtual break. A modification to the disclosed embodiment would be to pass (and create if necessary) HELLO messages whenever the preferred embodiment calls for a flagged HELLO and to augment that with another control signal message that indicates that a device has imposed a bidirectional break. The Slave Arbiter would react to the control signal message to remove the virtual break. One of ordinary skill in the art will recognize that a system using a separate control signal in lieu of the field in the flagged HELLOs could communicate to the Slaver Arbiter the need to re-impose the virtual break either by ceasing to send a control signal to remove the virtual break or by sending a control signal to re-impose the virtual break.
While discussing the flagged HELLO message it is worth noting that flagged HELLO protocol packets are sometimes called regenerated HELLO protocol packets or regenerated HELLO messages as ring relays “regenerate” HELLOs when they do not receive them. However as not all of these flagged HELLO messages are actually “regenerated,” flagged is a better descriptor that regenerated. The term “flagged” should not be read as limiting the way of distinguishing one type of HELLO from another to setting a flag value, although that is a suitable solution. Any readily discernible difference between the normal HELLOs and the flagged HELLOs such that the Slave Arbiter can discern the information conveyed by the use of the flagged HELLO is sufficient.
Unidirectional Transmission of Flagged HELLOs
Another variation on the preferred embodiment differs at the Ring Relay in that the Ring Relay would send flagged HELLOs out the partner port of the port with the failure on the incoming link but the outgoing link on the port with the failure on the incoming link would continue to get whatever HELLOs were received by the Ring Relay. For example, using FIG. 10 with all links operating including 11027 , if Ring Relay 1020 stopped receiving HELLOs on incoming link 11037 , then Ring Relay 1020 would send flagged HELLOs out link 11027 but would not replace the HELLOs received on link 11025 with flagged HELLOs for transmission on link 11035 . This reduces the actions necessary at Ring Relay 1020 .
In order for this variation to reliably provide the flagged HELLOs to the Slave Arbiter 1025 , the Master Arbiter 1000 would need to be modified to respond to the receipt of a flagged HELLO from an incoming link by reflecting back a flagged HELLO on the corresponding outgoing link on that same port. In this case a HELLO timeout on link 11037 would lead to the creation of a flagged HELLO at Ring Relay 1020 which would be passed over link 11027 to Ring Relay 1010 and then over link 11012 l to Master Arbiter 1000 . Master Arbiter 1000 would respond by sending a flagged HELLO out link 11010 to Ring Relay 1010 then over link 11025 to Ring Relay 1020 and finally over link 11035 to Slave Arbiter 1025 . In the event that the problem at 11037 was part of a bidirectional problem involving link 11037 , then Slave Arbiter 1025 would not receive the flagged HELLO from Master Arbiter 1000 but would respond to a HELLO timeout and impose a bidirectional break on its own.
Rings without a Master Arbiter
In yet another embodiment, Master Arbiter 1000 shown in FIG. 10 (with link 11027 assumed to be working in this example) could be removed from the ring so that Ring Relay 1010 is connected directly to Ring Relay 1005 . In this embodiment, the Slave Arbiter 1025 would be the only source of normal HELLOs. Each ring relay could send out flagged HELLOs in just the direction with the incoming link having a problem. For example, if incoming link 11025 for Ring Relay 1020 experienced a HELLO timeout as part of a unidirectional failure, then Ring Relay 1020 could send flagged HELLOs (or some other control signal) out 11027 and the flagged HELLO would reach the Slave Arbiter. The Slave Arbiter would react to an OPER DOWN or a lack of HELLOs as described above. In this embodiment, there is no need for the Slave Arbiter to switch from sending HELLOs to flagged HELLOs (those with the control signal noting that the Slave Arbiter is imposing a bidirectional break on a port) as only the Slave Arbiter reacts to a difference between a HELLO and a flagged HELLO.
Dual Homing Using a Single Node Ring
FIG. 11 shows an application of a particular embodiment of the present invention that is referred to as “dual homing”. Dual homing allows a Slave Arbiter Node 1130 to provide protected access for User Ports 1140 to network via Ring Access Equipment nodes 1110 and 1120 using redundant links 1160 and 1170 .
In this alternative embodiment, the Slave Arbiter node 1130 would see its own HELLOs. As described in Table C, one side of 1130 (for example the west side of the Slave Arbiter connected to link 1160 ) would go to the SLAVE FORWARDING state and one side (for example, the east side of the Slave Arbiter connected to link 1170 ) would go to the BLOCKED state.
Now, in response to a fault on the Ring Access Equipment 1110 or the link 1160 , the east side of the Slave Arbiter 1130 would unblock, and the User Ports 1140 would continue to have access to the network. The network access for User Ports 1140 is therefore protected against faults in either the access links ( 1160 and 1170 ) as well as in the Ring Access Equipment nodes ( 1110 and 1120 ).
Unidirectional Break for Dual Homing Using a Single Node Ring
FIG. 12 is another view of a Dual Homing application. Dual homing allows a Slave Arbiter Node 1230 to provide protected access for User Ports 1231 , 1232 , and 1233 to network via Ring Access Equipment nodes 1210 and 1220 using redundant links. In order to discuss a unidirectional break, the redundant links are shown in using the various unidirectional components: 1260 , 1261 , 1270 , and 1271 .
Through the use of FIG. 12 , it is possible to discuss an embodiment of a dual homing ring experiencing a unidirectional break. In this embodiment the following rules are followed;
No OPER DOWN and receiving HELLOs on both ports: Impose a virtual break on one bidirectional port as discussed in connection with FIG. 11 to block data packets but not control messages such as HELLOs. Experiencing a HELLO timeout on both ports or a HELLO timeout on one port and an OPER DOWN on the other port (indication a problem in Ring Access Equipment 1210 or 1220 or a bidirectional break: Remove the virtual break from the port with the imposed virtual break so that user ports can have access to the network through either access point (if either is working)). Experiencing an OPER DOWN or a HELLO timeout on one port but not the other (indicating a unidirectional break):
On the port with a failed receiver (either OPER DOWN or no HELLOs) impose a bidirectional break so that the virtual break can be removed without causing a unidirectional loop. After the bidirectional break is imposed, then remove the virtual break. After the problem with the receiver is corrected, then impose the virtual break before removing the bidirectional break.
For example, consider the case where 1230 is initially imposing a virtual break on its east side (links 1270 and 1271 ). Upon a HELLO timeout on link 1261 , Slave Arbiter 1260 it would impose a bidirectional break on links 1261 and 1260 and remove the virtual break on links 1270 and 1271 . After the problem with link 1261 was corrected, the virtual break would be imposed on links 1270 and 1271 and the imposed bidirectional break on links 1260 and 1261 would be removed a short time later. One of ordinary skill in the art will recognize that the imposition of a virtual break could be done on the opposite port from the port which most recently had the virtual break without deviating from the teachings of the present application.
If the lack of HELLOs was on the side with the imposed virtual break then the Slave Arbiter 1230 would impose a bidirectional break on links 1270 and 1271 before removing the pre-existing virtual break on links 1270 and 1271 . Upon receipt of HELLOs on link 1270 , the process would be reversed with the imposition of a virtual break on links 1270 and 1271 before removing the bidirectional break on links 1270 and 1271 . One of ordinary skill in the art could modify to the control rules to simply maintain the imposed break if called for by the rules for virtual breaks or if called for by the rules for bidirectional breaks rather than imposing and removing redundant breaks.
There is no need for flagged HELLOs in this situation as the only device that makes use of the distinction between a normal HELLO and a flagged HELLO is the slave arbiter that is sending the HELLOs.
Use of a Control Message in Place of the fd Timer
The preferred embodiments disclose using a timing delay to ensure that a port progressing from OPER DOWN to operational delays removal of the bidirectional break long enough for the Slave Arbiter to impose a virtual break. Likewise a port that had experienced a HELLO timeout delays removing the bidirectional break long enough for the Slave Arbiter to impose a virtual break. One of skill in the art will recognize that the use of the timer could be replaced by a control signal sent by the Slave Arbiter after it has successfully imposed the new break before removing the previously existing break. Analogous to the regenerate flag in the flagged HELLO message, this control signal could be a flag set in the HELLO protocol packet sent by the Slave Arbiter.
One of skill in the art will recognize that alternative embodiments set forth above are not universally mutually exclusive and that in some cases alternative embodiments can be created that implement two or more of the variations described above.
Those skilled in the art will recognize that the methods and apparatus of the present invention have many applications and that the present invention is not limited to the specific examples given to promote understanding of the present invention. Moreover, the scope of the present invention covers the range of variations, modifications, and substitutes for the system components described herein, as would be known to those of skill in the art.
The legal limitations of the scope of the claimed invention are set forth in the claims that follow and extend to cover their legal equivalents. Those unfamiliar with the legal tests for equivalency should consult a person registered to practice before the patent authority which granted this patent such as the United States Patent and Trademark Office or its counterpart.
ACRONYMS
ES Extension Side
FR Full Ring
HA High Availability
IP Internet Protocol
MAC Media Access Control
MPLS Multiprotocol Label Switching
PDU Packet Data Unit
PSR Protected Switching Ring
RA Ring Arbiter
RPR Resilient Packet Ring
RR Ring Relay
RS Ring Side
TCP Transmission Control Protocol
UDP User Datagram Protocol
|
Normal 802.3 Ethernet requires a tree topology. If a ring or a loop exists, then packets will be forwarded around the ring indefinitely. If the ring is broken, then there is no possibility of packets being propagated forever. This invention shows how to quickly impose a virtual break in the ring such that all nodes can communicate with each other, and how to remove the virtual break when a real failure occurs. This is accomplished by placing intelligent nodes on the ring that work together to virtually break and restore the ring. An embodiment is disclosed that handles a unidirectional break in a communication link where the unidirectional break is not sensed as an OPER DOWN state. This abstract is provided as an aid to those performing prior art searches and not a limitation on the scope of the claims.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 918,550, filed June 23, 1978, which is a continuation-in-part of copending application Ser. No. 817,943, filed July 22, 1977, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates (a) to novel pyridinyl oxyphenoxy propanoic acids, salts and esters thereof and pyridinyloxyphenoxy propanols and esters and ethers thereof, and propionitriles, and the corresponding 2-((4-pyridinyl-2-thio)phenoxy) propanoate and propanol compounds, (b) to herbicidal compositions of such novel compounds and (c) to preemergent and postemergent methods of using such compounds for the control of grassy weeds in non-crop areas as well as in the presence of some specified valuable crops.
2. Description of the Prior Art
Belgian Pat. No. 834,495, issued Feb. 2, 1976, as well as the published German patent application equivalent thereto, viz., No. 2,546,251, published Mar. 29, 1976, describe 2-((4-pyridinyl-2-oxy)phenoxy)alkanoic acids, salts and esters having halo substitution in the 3 and/or 5 ring positions in the pyridine ring. Published Japanese patent application No. 129313/75, filed in Japan Oct. 29, 1975 teaches pyridyloxyphenoxypropanols and esters thereof, while published Japanese patent application No. 064,160/75, filed May 30, 1975, teaches pyridyloxyphenoxypropionitrile compounds. The patent disclosures do not teach or suggest, however, trifluoromethyl substitution at any position in the pyridine ring of such compounds. These prior art compounds are disclosed to be active herbicides useful in the control of grassy weeds.
SUMMARY OF THE INVENTION
The present invention is directed to novel pyridinyloxyphenoxy propanoic acids, salts and esters having trifluoromethyl substitution in the pyridine ring according to the following formula: ##STR1## wherein: T is oxygen or sulfur;
X is Cl, Br or CF 3 ;
Y is H, Cl, Br or CF 3 , provided at least one of X and Y is CF 3 ;
Z is ##STR2## R 1 is H, C 1 -C 8 alkyl, benzyl, chlorobenzyl or C 3 -C 6 alkoxyalkyl;
R 4 is C 1 -C 4 alkyl;
R 5 is H or C 1 -C 4 alkyl;
R 6 is C 1 -C 7 alkyl;
M is --NHR 2 R 3 R 7 , Na, K, Mg or Ca;
R 2 and R 3 are each independently selected from R 7 or --OCH 3 , provided both R 2 and R 3 cannot be simultaneously --OCH 3 and neither is --OCH 3 in --NHR 2 R 3 R 7 ; and
R 7 is H, C 1 -C 4 alkyl or C 2 -C 3 hydroxyalkyl.
The compounds of the above formula, hereinafter referred to for convenience as "active ingredients", have been found to be especially active as herbicides for the control of undesired vegetation, for example, grassy or graminaceous weeds. Accordingly, the present invention also encompasses compositions containing one or more active ingredients as well as preemergent and postemergent methods of controlling undesired plant growth, especially in the presence of valuable crops. Such methods comprise applying a herbicidally-effective amount of one or more active ingredients to the locus of the undesired plants, that is, the seeds, foliage, rhizomes, stems and roots or other parts of the growing plants or soil in which the plants are growing or may be found.
DETAILED DESCRIPTION OF THE INVENTION
The term "herbicide" is used herein to mean an active ingredient which controls or adversely modifies the growth of plants because of phytotoxic or other effects substantial enough to seriously retard the growth of the plant or further to damage the plant sufficiently to kill the plant.
By "growth controlling" or "herbicidally-effective" amount is meant an amount of active ingredient which causes a modifying effect and includes deviations from natural development, killing, regulation, desiccation, retardation, and the like.
The term "plants" is meant to include germinant seeds, emerging seedlings, rhizomes and established vegetation.
The terms "C 1 -C 4 alkyl" or "C 1 -C 7 alkyl", e.g., refer to different size alkyl groups which may be straight or branched.
The term "C 3 -C 6 alkoxyalkyl", for example, is meant to refer to an alkoxyalkyl group having three to six carbon atoms, the alkyl portion being straight or branched.
The active ingredients of the present invention are generally oils or crystalline solids at ambient temperatures which are soluble in many organic solvents commonly employed as herbicidal carriers. The active ingredients of the above formula wherein T is oxygen, X is CF 3 , Y is Cl or H, and Z is ##STR3## wherein R 1 is C 1 -C 8 alkyl constitute preferred embodiments of the present invention. The active ingredients of the above formula wherein T is oxygen, X is CF 3 , Y is Cl, Br, CF 3 or hydrogen, Z is ##STR4## wherein R 2 and R 3 are each independently hydrogen-OCH 3 , or C 1 -C 4 alkyl constitute additional preferred embodiments. Yet additional preferred embodiments are the present compounds wherein T is sulfur, X is CF 3 , Y is Cl, and Z is ##STR5## wherein R 1 is H or C 1 -C 8 alkyl.
The active ingredients, i.e., new compounds, of the present invention wherein T is oxygen are readily prepared by the reaction of 4-hydroxyphenoxy-2-propanoic acid or an ester thereof with a substituted pyridine having the requisite substitution in the 3- and/or 5-ring positions in addition to 2-halo substiturion. The pyridine compound used as starting material is itself prepared from a 2 halopyridine compound, generally the 2-chloro substituted compound, having trichloromethyl substitution in either or both of the 3- and 5-ring positions in addition to any desired chloro or bromo substitution at the 3- or 5-positions, if not occupied by a CCl 3 group, by reacting the pyridine compound with a fluorinating material such as antimony trifluoride whereupon the trichloromethyl group or groups are converted to trifluoromethyl groups, as well understood in the art.
The new compounds of the present invention wherein T is sulfur are similarly prepared by the reaction of 4-mercaptophenoxy-2-propanoic acid or an ester thereof with an appropriate substituted pyridine in substantially the same manner as described above.
The reaction between such a substituted pyridine and the said hydroxy- or mercapto-phenoxy propanoic acid is rather readily carried out in a polar solvent such as dimethyl sulfoxide to which has been added a small amount of aqueous or powdered sodium hydroxide. Reaction is usually carried out at a temperature in the range of about 70 to about 125° C. over a period of about 1 to 3 hours under ambient atmospheric pressure. The reaction mixture is then allowed to cool and is poured into a quantity of cold water and acidified with hydrochloric acid, whereupon the product precipitates and is separated and purified as may be required.
The propanoate esters of the present invention may be prepared in substantially the same manner as set forth above for the propanoic acids, using the requisite ester of 4-hydroxyphenoxy-2-propanoic acid or 4-mercaptophenoxy-2-propanoic acid to react with the appropriately substituted 2-halopyridine. Or, if desired, the appropriate propanoic acid of the invention is esterified by first converting to the acid chloride with thionyl chloride and then reacting the acid chloride with the appropriate alcohol, or, mercaptan, such as, ethyl mercaptan, propyl mercaptan or butyl mercaptan, according to generally accepted procedures or the classic method of reacting an alcohol and an acid in the presence of a little sulfuric acid may be followed.
It is also within the scope of the present invention to employ acid halides other than the acid chloride as a reactant. It is to be understood that the acid halides such as the acid bromide can be employed to give substantially the same results. The preparation of such acid bromides are known to those skilled in the art.
The propanoic acid compounds of the invention after conversion to the acid chloride may also be reacted with (a) ammonia to form the simple amide, (b) with an alkyl amine to form an N-alkyl amide or N,N-dialkyl amide, or (c) with a methoxy amine to form an alkoxy amide.
The simple amide serves as preferred starting material for the manufacture of the present nitriles, which are obtained upon reaction of the amide with phosphorous oxychloride.
The propanoate metal salts of the invention are prepared from the propanoic acid form of the compound by simply reacting the carboxylic acid with the requisite inorganic base, such as NaOH, KOH, Ca(OH) 2 or Mg(OH) 2 . The amine salts are prepared by reacting the propanoic acid compound with the requisite amine, for example, triethanolamine or trimethylamine.
The compounds according to the invention which are substituted propanols are prepared preferably from one of the above described esters of the propanoic acid form of the compound, such as the methyl ester, by reaction of the ester with sodium borohydride in a polar solvent medium such as methanol, reaction being carried out initially at a temperature below about 30° C. during an initial period of 1 to 2 hours after which the temperature is brought to about 50° to 60° C. and the solvent then stripped off. The reaction product is then admixed with water and extracted with a water-immiscible organic solvent. Removal of the solvent leaves an oily product.
Esterification of such alcohol is carried out according to methods generally known in the art in which, e.g., an acid chloride is reacted with the alcohol in solvent medium in the presence of a hydrogen chloride acceptor, such as triethylamine. The hydrochloride salt is filtered off and the solvent stripped, leaving an oily product.
Ethers of the alcohols of the invention are prepared by reacting the alcohol with, e.g., sodium hydride in a polar solvent such as dimethyl formamide at a temperature of about 35° to 60° C., after which an alkyl bromide is added to the reaction mixture and heated to 75° to 100° C. for one to two hours. The solvent medium is then stripped off under reduced pressure and the crude product is poured into cold water and final product taken up with water immiscible solvent such as heptane. The solvent, on being stripped off, leaves an oily product.
In an alternate process for making the present propanoic acid compounds, a salt, e.g., the sodium salt, of 4-methoxyphenol, or of 4 mercaptophenol, is dissolved in a solvent such as dimethyl sulfoxide and the requisite trifluoromethyl-substituted 2-chloropyridine is added to the solution of the methoxy phenol and reacted in the presence of a little aqueous sodium hydroxide at a temperature in the range of about 70° to 130° C. and over a time interval of about 30 to 45 minutes. The reaction mixture is then cooled somewhat and poured over ice. The solid product is filtered off and washed with water and taken up in a solvent mixture and reprecipitated therefrom. The methoxy group, if present, is then cleaved off the phenyl ring by refluxing the compound in 48% by weight HBr for about an hour and after purification, precipitated from acidic solution and recovered, as by filtration, and dried. The trifluoromethyl-substituted 2-pyridinyloxy phenol, or trifluoromethyl-substituted 2-pyridinylthiophenol, is then dissolved in a solvent such as dimethyl sulfoxide, anhydrous powdered sodium hydroxide is added thereto and reacted therewith for a few minutes at about 75° to 85° C. Then an ester, such as the ethyl ester, of 2-bromopropanoic acid is added to the reaction mixture and stirred for a time, such as about half an hour, at approximately 100° C. or up to about 2 hours in the case of the sulfur bridged compound. The reaction mixture is then allowed to cool and poured over ice or simply into cold water whereupon an oily layer separates which can be recovered by taking up in a water-immiscible solvent and subsequently stripping the solvent off leaving an oily product. The product so obtained will be the alkyl ester of the propanoic acid compound. In carrying out the several reactions of this alternate process, the reactants are usually mixed with a carrier medium, such as, for example, methylethyl ketone, methylisobutyl ketone or an aprotic polar solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, hexamethylphosphoramide or sulfolane. The first step condensation is generally carried out at a temperature of at least 50° C., preferably about 70° to about 150° C. and during a reaction period of about 1 to about 20 hours, preferably about 1 to about 10 hours. The second condensation reaction is carried out under similar reaction conditions except that the reaction is usually accomplished in a shorter period of time such as about 0.5 to 10 hours, typically using one of the aprotic solvents such as dimethylsulfoxide as reaction medium. The dealkylation step, where employed, is carried out using as a suitable dealkylation agent, a hydro acid such as hydrobromic acid or hydriodic acid employed as a concentrated aqueous solution of about 40 to about 60 percent by weight concentration. Reaction is carried out at a reflux temperature which usually falls in the range of about 75° to about 150° C. but preferably is about 100° C. to 140° C. The dealkylation reaction is generally completed in about 1 to about 10 hours.
The active ingredients of the above formula wherein Z is --CH 2 OOCR 6 are readily prepared from the requisite 2-propanoic acid compound, prepared as described above, followed by esterification with a primary alcohol conveniently available, such as methanol, and in the presence of a small amount of sulfuric acid, after which the ester is reduced to the alcohol upon reaction with sodium borohydride in aqueous medium and at close to ambient room temperature. After removal of excess primary alcohol the product is extracted from the reaction mixture with a water-immiscible solvent or solvent mixture such as methylene chloride-heptane. Finally, the solvent is stripped off and removed under reduced pressure leaving the product which is usually an oil.
The so-produced substituted propanol is esterified, if desired, by reacting it with the acid chloride of the esterifying acid in solvent medium, such as toluene, containing in admixture, an HCl acceptor such as triethyl amine. Reaction proceeds steadily over about a 1 to 1.5 hour period at a temperature in the range of about 100° to about 135° C. The precipitated trialkylamine hydrochloride is filtered off and the solvent medium stripped off. Subsequently, the residue is preferably washed with water and then taken up in hot heptane, dried, and the heptane distilled off leaving an oily product.
The substituted propionitriles of the invention are prepared using the propanoic acid compound as the starting material. The carboxylic acid is reacted with thionyl chloride to form the acid chloride which is in turn reacted with NH 4 OH to produce the amide. The amide is reacted with POCl 3 to form the nitrile.
The following examples illustrate the present invention and the manner by which it can be practiced but as such are not to be construed as limitations upon the overall scope of the invention.
EXAMPLE 1
2-Chloro-5-(trichloromethyl)pyridine (23.0 grams ("g"); 0.1 mole) was mixed with antimony trifluoride (22.3 g; 0.125 mole) and then chlorine gas (9.0 g; 0.126 mole) was passed into the stirred mixture over a period of 8 minutes during which time the temperature rose from ambient to 100° C. The reaction mixture was stirred for an additional 20 minutes before adding 25 milliliters of concentrated HCl plus 27 milliliters of water and steam distilling off any unreacted starting material and volatile chlorides and fluorides. Thereafter, pentane was added to the receiver vessel to take up the solid product which was subsequently recovered by distilling off the solvent.
The crystalline product obtained had a melting temperature of 30°-31° C. and upon analysis was found to contain 39.56% carbon; 1.78% hydrogen; 7.72% nitrogen; and 19.42% chlorine. The theoretical composition for 2-chloro-5-(trifluoromethyl)pyridine is 39.69% carbon; 1.66% hydrogen; 7.72% nitrogen; and 19.53% chlorine.
The following substituted pyridines are prepared in a similar manner:
______________________________________Ring Substituents On Pyridine2 3 5 Physical Property______________________________________Cl CF.sub.3 CF.sub.3 (B.P.) 94-96° C. @ 109 mm HgCl Cl CF.sub.3 (B.P.) 50-51° C. @ 21 mm HgCl CF.sub.3 Cl n.sup.25° = 1.4825Cl Br CF.sub.3______________________________________
EXAMPLE 2
2-(4-hydroxyphenoxy)propanoic acid (2.35 g; 0.0129 mole) was dissolved in dimethylsulfoxide (16 ml) and then a solution of sodium hydroxide (1.06 g; 0.026 mole) in 3.5 ml of water was added. This mixture was stirred and heated to about 60° C. over a 20 minute period in order to insure formation of the disodium salt. Next a solution of 2-chloro-3,5-bis(trifluoro methyl)pyridine (2.73 g; 0.0129 mole) in 8 ml of dimethylsulfoxide reaction medium was added over a 3 minute period and the mixture then warmed to 110° C. in 35 minutes. The mixture was then heated at 105°-110° C. for an additional 45 minutes, allowed to cool for 30 minutes, and then poured into cold water. The resulting crude, gummy product was taken up in hot toluene, treated with activated charcoal, and filtered. The toluene was then flashed off and the product was extracted with pentane which was chilled resulting in the separation of a crystalline product having a melting temperature of 80.5°-83° C. The product was found on analysis to contain 48.87% carbon; 3.14% hydrogen; and 3.59% nitrogen. The theoretical composition for 2-(4-(3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid is 48.62% carbon; 2.80% hydrogen; and 3.54% nitrogen, thus confirming the obtention of the anticipated product.
In a manner similar to the foregoing procedure, using the requisite starting materials, the following 4-pyridinyloxyphenoxy propanoic acid compounds of the invention are prepared:
______________________________________RingSubstituentsOn Elemental Analysis,Pyridine Melting % By Weight*3 5 Temperature, °C. C H N Cl______________________________________Cl CF.sub.3 105.5-107 49.73 3.25 3.78 9.66 (49.81) (3.06) (3.87) (9.80)CF.sub.3CF.sub.3 80.5-83 48.87 3.14 3.59 -- (48.62) (2.80) (3.54)-- CF.sub.3 97-100 54.91 3.77 4.27 -- (55.05) (3.70) (4.28)CF.sub.3Cl 115-118 49.79 3.21 3.99 9.77 (49.81) (3.06) (3.87) (9.80)Br CF.sub.3CF.sub.3Br______________________________________ *Theoretical composition shown in parenthesis
EXAMPLE 3
3,5-bis(trifluoromethyl)-2-pyridinyloxy-4-phenoxypropanoic acid (16.0 g; 0.0405 mol) was refluxed with 110 ml of thionyl chloride for 26 minutes and then the unreacted thionyl chloride was distilled off. The resulting acid chloride was put into 40 ml of methanol. Triethylamine (5.2 g; 0.0514 mol) was put into 75 ml of methanol. The acid chloride solution was then added and the reaction mixture was taken to reflux and refluxed for 30 minutes. The methanol was removed by distillation and the crude product was washed with water and taken up in heptane. The heptane was removed and 15 grams of amber oil was obtained which had a refractive index of 1.4832 at 25° C.
The product had the following elemental analysis:
______________________________________ C H N______________________________________Calculated 49.88 3.20 3.42Found 49.97 3.20 3.52______________________________________
These results confirm the obtention of methyl 2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoate.
Other active ingredients of the present invention are similarly prepared by employing procedures analogous to those set forth in the above example and the foregoing teachings of the specification. Such other active ingredients include the following compounds:
__________________________________________________________________________ ##STR6## Elemental Analysis, % By Weight*X Y R Refractive Index @ 25° C. C H N Cl__________________________________________________________________________CF.sub.3 CF.sub.3 (CH.sub.2).sub.7 CH.sub.3 1.4743 55.65 5.02 2.96 -- (56.80) (5.36) (2.76)Cl CF.sub.3 (CH.sub.2).sub.3 CH.sub.3 1.5076 54.49 4.69 3.41 8.60 (54.62) (4.58) (3.35) (8.49)CF.sub.3 Cl (CH.sub.2).sub.3 CH.sub.3 1.5080 54.61 4.65 3.34 8.47 (54.62) (4.58) (3.35) (8.49)Br CF.sub.3 C.sub.2 H.sub.5CF.sub.3 H ##STR7## 1.5432 49.94 (51.07) 2.76 (2.68) 7.25 (7.44)CF.sub.3 Br ##STR8##CF.sub.3 H (CH.sub.2).sub.2 CH.sub.3CF.sub.3 Cl CH.sub.2CH.sub.2OC.sub.4 H.sub.9CF.sub.3 -- ##STR9##CF.sub.3 CF.sub.3 (CH.sub.2 CH.sub.2 O) .sub.5HCF.sub.3 Cl ##STR10##CF.sub.3 Cl CH.sub.2CH.sub.2OCH.sub.3CF.sub.3 Cl (CH.sub.2).sub.2O(CH.sub.2).sub.3 CH.sub.3 1.5061 54.61 5.02 3.03 7.68__________________________________________________________________________ *Theoretical composition shown in parenthesis
In a similar manner to the foregoing Example 3 butyl mercaptan was used instead of methanol and the compound obtained having a refractive index at 25° C. of 1.5330 was 2-(4-(3-chloro-5-trifluoromethyl)-2-pyridinyloxy)phenoxy prophanethioic acid, -s-butyl ester.
EXAMPLE 4
To 5.0 g (0.0138 mole) of 2-(4-(3-chloro-5-(trifluoromethyl)pyridinyl-2-oxy)phenoxy)propanoic acid was added 30 ml of SOCl 2 and the mixture heated at reflux for about 20 minutes after which unreacted SOCl 2 was removed on a still under water aspirator vacuum. The resulting syrup was added to a stirred solution of 30 ml (0.028 mole) of concentrated aqueous. NH 4 OH in 40 ml of acetonitrile. The mixture was stirred at a temperature of 25° C. for 15 minutes and filtered, thus recovering crystals of solid product which had formed. The recovered crystals exhibited a melting temperature of 140°-42° C. On elemental analysis, the crystals were found to contain 49.50% carbon; 3.44% hydrogen; 10.01% chlorine; and 7.76% nitrogen. Theoretical composition for 2-(4-(3-chloro-5-(trifluoromethyl)pyridinyl-2-oxy)phenoxy)propionamide is 49.94% carbon; 3.35% hydrogen; 9.83% chlorine; and 7.76% nitrogen.
Other 2-((4-(trifluoromethyl substituted)-2-pyridinyl)oxy)phenoxypropionamides of the invention are prepared using procedures similar to the foregoing using the requisite starting materials. Such active ingredients include the following compounds:
__________________________________________________________________________ ##STR11## Elemental Analysis, % By Weight*X Y A Melting Temperature °C. C H N Cl__________________________________________________________________________Cl CF.sub.3 NH.sub.2 151-152 48.56 3.37 7.57 9.57 (49.94) (3.35) (7.77) (9.83)CF.sub.3 Cl NHCH.sub.3 146-147 51.14 3.73 7.37 9.63 (51.78) (3.76) (7.47) (9.46)CF.sub.3 CF.sub.3 N(n-C.sub.4 H.sub.9).sub.2 (n.sup.25° = 1.4844) 56.30 5.48 5.06 -- (56.91) (5.57) (5.33)CF.sub.3 -- N(CH.sub.3).sub.2 (n.sup.25° = 1.5247) 57.99 5.04 7.74 -- (57.6) (4.84) (7.9)CF.sub.3 -- NH.sub.2 69-70 55.3 4.09 8.62 -- (55.22) (4.02) (8.58)CF.sub.3 CF.sub.3 NH.sub.2 150.5-152 48.78 3.17 6.96 (48.75) (3.05) (7.1)CF.sub.3 Br NH.sub.2 --CF.sub.3 Cl NHCH.sub.3 146-147 51.19 3.73 7.37 9.63 (51.28) (3.76) (7.47) (9.46)CF.sub.3 -- NHCH.sub.3CF.sub.3 Cl NHnC.sub.4 H.sub.9Br CF.sub.3 NHnC.sub.3 H.sub.7CF.sub.3 -- NHOCH.sub.3CF.sub.3 Cl NHCH.sub.2 CH.sub.2 OH (n.sup.25 1.5434) 50.71 3.81 6.41 8.96 (50.44) (3.98) (6.92) (8.76)CF.sub.3 Cl NHOCH.sub.3 135-6__________________________________________________________________________ *Theoretical composition shown in parenthesis
EXAMPLE 5
5-chloro-3-trifluoromethyl-2-pyridinyloxy-4-phenoxypropionamide (4.5 g; 0.01248 mols) was refluxed with 20 ml of phosphorous oxychloride for a total time of 1 hour and 45 minutes. The POC13 was distilled off and the remaining reaction mixture was poured over ice and extracted with heptane. On cooling a crystalline product was obtained with a melting range of 61.5°-62.5° C. The anticipated product was 2-(4-(5-chloro-3-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propionitrile. The following elemental analysis was obtained:
______________________________________ C H N Cl______________________________________Calculated 52.57% 2.94% 8.18% 10.35%Found 52.48% 3.01% 8.17% 10.14%______________________________________
Other active nitrile compounds of the present invention are similarly prepared by employing the procedures analogous to those set forth in the above example and the foregoing teaching of the specification. Such other active ingredients include the following compounds:
______________________________________ ##STR12## Elemental Analysis,Melting % By Weight*X Y Temperature °C. C H N Cl______________________________________CF.sub.3Cl 49-52 52.71 3.07 10.47 7.47 (52.57) (2.94) (10.35) (8.17)CF.sub.3-- 38-40 58.16 3.79 8.81 -- (58.44) (3.57) (9.08)CF.sub.3CF.sub.3 54-55 49.94 2.76 7.25 (51.07) (2.68) (7.44)Br CF.sub.3 --Cl CF.sub.3 61.5-62.5 52.48 3.01 8.17 10.14 (52.57) (2.94) (8.18) (10.35)______________________________________ *Theoretical composition shown in parenthesis
EXAMPLE 6
In each of a series of metal salt preparations 60 milligrams (mg) of one of the propanoic acids of the invention was stirred into several milliliters (ml) of water and (an aqueous solution of base added thereto in the amount needed for neutralization plus a slight excess estimated to be 10% excess upon obtaining a color change to yellow green in universal indicator. The propanoic acids, the molar amounts employed, the bases employed and the estimated amounts of such bases are tabulated as follows, the propanoic acid being identified by ring substitution on the pyridinyl ring:
______________________________________Ring Substituents Propanoic mg of5 3 Acid, mols. Base Base (estimated)______________________________________CF.sub.3 -- 0.183 NaOH 7.34CF.sub.3 Cl 0.165 KOH 9.25CF.sub.3 CF.sub.3 0.152 *NH.sub.4 OH 5.32______________________________________ *The NH.sub.4 OH was employed in the form of concentrated ammonium hydroxide.
The aqueous solutions so obtained are conveniently used in herbicidal applications with or without further dilution. The salts may be recovered by evaporation of the water from the solutions and purified by careful recrystallization, if desired.
The magnesium and calcium salts of the identified propanoic acids as well as the other propanoic acids of the invention are prepared in substantially the manner described above.
EXAMPLE 7
In each of a series of amine salt preparations 60 mg of one of the propanoic acids of the invention was stirred into several ml of water and a solution of alkyl amine or alkanolamine added thereto in the amount needed for neutralization plus an estimated 10 percent excess of base believed to be reached upon titrating to the yellow-green color of universal indicator. The propanoic acids, here identified by ring substituents, the molar amount of propanoic acid, the base employed and the estimated amounts of each base, are tabulated as follows:
______________________________________Ring Substituents Propanoic mg of5 3 Acid, mols. Base Base (estimated)______________________________________CF.sub.3 -- 0.183 NH.sub.2 C.sub.2 H.sub.5 OH 11.19CF.sub.3 Cl 0.165 (C.sub.2 H.sub.5).sub.3 N 16.68Cl CF.sub.3 0.165 C.sub.2 H.sub.5 NH.sub.2 7.43______________________________________
The aqueous solutions so obtained are conveniently used in herbicidal applications with or without further dilution. The salts may be recovered by evaporation of water from the solutions and purified by careful recrystallization, if desired.
The preparation of other amine salts such as the triethanolamine and diethanolamine salts, the tripropylamine salt and the butylamine salts are prepared in substantially the manner described above.
EXAMPLE 8
Sodium borohydride (6.35 g; 0.1716 mols) was dissolved in 25 ml of water and added over a ten minute period to a solution of methyl 2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propionate (11.7 g; 0.02859 mols) dissolved in 155 ml of warm methanol. During the addition the temperature was kept between 25° and 30° C. The mixture was allowed to stir at room temperature for 40 minutes and was then allowed to warm to 42° C. over a 25 minute period. The methanol was then removed by distillation and cold water was added to the crude product which was then extracted with a methylene chloride-heptane mixture. The solvents were distilled off leaving an orange colored oil with an index of refraction of 1.5028 at 25° C. The anticipated product was 2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanol. The product had the following elemental analysis:
______________________________________ C H N______________________________________Calculated 50.40% 3.44% 3.67%Found 51.01 3.64 3.86______________________________________
Other pyridinyloxyphenoxypropanols of the present invention are similarly prepared by employing procedures analogous to those set forth in the above example and the foregoing teachings of the specification. Such compounds include the following:
______________________________________ ##STR13## Elemental Analysis,Refractive % By Weight*X Y Index @ 25° C. C H N Cl______________________________________CF.sub.3Cl 1.5377 51.75 3.91 4.04 10.32 (51.81) (3.77) (4.03) (10.2)CF.sub.3--CF.sub.3BrCl CF.sub.3Br CF.sub.3______________________________________ *Theoretical composition shown in parenthesis
EXAMPLE 9
2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanol (5.45 g; 0.0171 mols) were taken up in 75 ml of toluene and placed in a round bottom reaction flask and 1.8 g of triethylamine was added thereto. Then octoyl chloride (3.05 g; 0.01875 mols) as a solution in 18 ml of toluene was added to the propanol over a 3 minute period at a temperature in the range of 25°-30° C. The mixture was stirred for about an hour at ambient room temperature and then refluxed for about one hour. At the end of the reaction period, the separated hydrochloride salt was filtered off and the toluene was stripped off on a rotary evaporator. The residue was poured into ice water and taken up by extraction with heptane. The heptane extracts were dried and the heptane was removed by distillation, leaving an oil with a refractive index of 1.4740 at 25° C. The anticipated product was 2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propyl octanoate. The product had the following elemental analysis:
______________________________________ C H N______________________________________Calculated 56.80 5.36 2.76Found 58.0 5.88 2.79______________________________________
Other propyl esters of the present invention are similarly prepared by employing procedures analogous to those set forth in the above example and the foregoing teachings of the specification. Such other active ingredients include the following compounds:
__________________________________________________________________________ ##STR14## Elemental Analysis, % By Weight*X Y B Refractive Index @ 25° C. C H N Cl__________________________________________________________________________CF.sub.3 Cl CH.sub.3 1.5230 52.26 3.99 3.69 9.38 (52.38) (3.88) (3.59) (9.10)CF.sub.3 -- (CH.sub.2).sub.6 CH.sub.3CF.sub.3 Cl C.sub.2 H.sub.5CF.sub.3 Br CH.sub.3CF.sub.3 CF.sub.3 i-C.sub.3 H.sub.7Cl CF.sub.3 (CH.sub.2).sub.2OC.sub.2 H.sub.5__________________________________________________________________________ *Theoretical composition shown in parenthesis
EXAMPLE 10
Sodium hydride (0.8 g; 0.0334 mols) is dissolved in 30 ml of dry dimethyl formamide and then a solution of 2-(4-((3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanol (5.5 g; 0.0176 mols) in 50 ml of dry dimethylformamide is added to the sodium hydride solution over a four minute period and then stirred for an hour at 40°-50° C. A solution of 1-bromobutane (2.4 g; 0.0175 mols) in 25 ml of dry dimethylformamide is then added over a six minute period. The reaction mixture is then slowly heated to 90° C. over a 30 minute period and held at 90° C. for an hour and ten minutes. The reaction mixture is then stirred and heated at 105°-115° C. for 2 hours. The dimethylformamide is then stripped off under partial vacuum and the crude product poured into cold water and extracted with heptane. The heptane is removed by distillation leaving an oil as product.
Other active ingredients of the present invention are similarly prepared by employing procedures analogous to those set forth in the above example and the foregoing teachings of the specification. Such other active ingredients include the following compounds:
______________________________________ ##STR15##X Y E______________________________________CF.sub.3 CF.sub.3 C.sub.2 H.sub.5CF.sub.3 -- CH.sub.3Cl CF.sub.3 n-C.sub.4 H.sub.9CF.sub.3 Br i-C.sub.3 H.sub.7CF.sub.3 Cl ##STR16##CF.sub.3 -- ##STR17##CF.sub.3 Cl SO.sub.3 Na______________________________________
EXAMPLE 11
The following series of preparations illustrate an alternate method of synthesizing the propanoate esters and from such compounds the propanoic acids of the invention. A solution of the sodium salt of 4-methoxy phenol was prepared by dissolving the methoxy phenol (7.45 g; 0.06 mole) in 45 ml of dimethylsulfoxide and adding a solution of sodium hydroxide (2.4 g; 0.06 mole) in 7 ml of water. A solution of 2-chloro-5-(trifluoromethyl)pyridine (9.0 g; 0.05 mole) in 40 ml of dimethylsulfoxide was then added to the above sodium phenate solution over an 11 minute period. During the addition, the temperature rose to about 80° C. and then the reaction mixture was heated to 124° C. over a 26 minutes interval and the temperature maintained for 15 minutes. At the end of this time, the reaction mixture was cooled to 75° C. and poured over ice. The solid product was collected on a filter, washed and taken up in a toluene-hexane mixture. This solution on cooling yielded 9.7 grams of solid product having a melting temperature of 49.5°-50.5° C. and having a composition of 58.02% carbon; 3.86% hydrogen; and 5.22% nitrogen. The theoretical composition is 57.99% carbon; 3.74% hydrogen; and 5.20% nitrogen, confirming the product to be 5-(trifluoromethyl)-2 -(4-methoxyphenoxy)pyridine.
The 5-(trifluoromethyl)-2-(4-methoxyphenoxy)-pyridine (10.95 g; 0.0407 mole) was refluxed with 50 ml of 48 percent by weight aqueous hydrobromic acid solution for one hour. At the end of this time, the reaction mixture was cooled, poured over ice and the separated solids collected on a filter. The product was purified by taking it up in dilute caustic solution, extracting the solution with chloroform to remove unreacted starting material and then acidifying the solution to precipitate free phenol. The dried crystalline phenol product had a melting temperature of 89°-91° C. and was found to contain 56.21% carbon; 3.27% hydrogen; and 5.44% nitrogen. The theoretical composition of 4-(5-(trifluoromethyl)-2-(pyridinyl)oxy)phenol is 56.48% carbon; 3.16% hydrogen; and 5.49% nitrogen.
The 4-(5-(trifluoromethyl)-2-(pyridinyl)oxy)-phenol (4.95 g; 0.0194 mole) was dissolved in dimethylsulfoxide (41 ml) as reaction medium, then sodium hydroxide (0.78 g; 0.014 mole) was added as a dry powder and the mixture stirred for about 10 minutes and warmed to about 80° C. Ethyl-2-bromopropionate (4.2 g; 0.0233 mole) was then added in one portion and the mixture stirred for about 35 minutes at 96° C. The solution was then cooled, poured over ice and the oil which separated taken up in petroleum ether containing 20 percent by volume methylene chloride. The separated solvent phase was stripped of solvent leaving an oily product weighing 6.3 g. An infrared scan of a sample of the oil confirmed the ester structure of the anticipated ethyl-2-(4-(5-(trifluoromethyl)-2-pyridinyl)-oxy)phenoxy)propionate.
Ethyl-2-(4-(5-(trifluoromethyl)-2-pyridinyl)-oxy)phenoxy)propionate (6.3 g; 0.0177 mole) was dissolved in 28 ml of 2-B-ethanol and a solution of sodium hydroxide (1.06 g; 0.0266 mole) in 28 ml of water was added. The reaction mixture was heated to 75° C. for 5 minutes and then poured into 150 ml of cold water and acidified with 4 g of concentrated hydrochloric acid. The crude acid product which precipitated was washed with hot petroleum ether and dried. The resulting product exhibited a melting temperature of 97°-100° C. and was found on analysis to contain 54.91% carbon; 3.77% hydrogen; and 4.28% nitrogen. The theoretical composition for 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propionic acid is 55.05% carbon; 3.70% hydrogen; and 4.28% nitrogen, indicating the expected product was obtained.
Other active ingredients of the present in vention in which Z in the structural formula set forth is ##STR18## are similarly prepared by employing procedures analogous to those set forth in the above example and the foregoing teachings of the specification by reacting the appropriately substituted 2-halopyridine with 4-methoxy phenol, hydrolyzing the 4-methoxy group to a 4-hydroxy group, and condensing the pyridinyloxy phenol with an alkyl 2-bromopropanoate ester, the ester being then hydrolyzed if it is desired to obtain the propanoic acid form of the compound.
EXAMPLE 12
4-Mercaptophenol (7.6 gm., 0.06 moles) was dissolved in 70 ml of dimethylsulfoxide and a solution of sodium hydroxide (2.4 gm., 0.6 moles) in 3.0 ml of water was added. The mixture was warmed to 50° and stirred under nitrogen for 10 minutes to form the sodium thiophenate salt. A solution of 2-chloro-5-(trifluoromethyl)pyridine (10.9 gm., 0.06 moles) in 60 ml of dimethylsulfoxide was then added all at once. The mixture was heated to 100° and held there for 11/2 hours. At the end of this time it was poured into 500 ml of cold water. An emulsion formed therefore 60 ml of a saturated solution of ammonium chloride was added. The product precipitated as a sticky solid. The aqueous layer was decanted, the solid washed with more water then taken up in hot heptane, dried with solid sodium sulfate and decolorized with Norite. In the filtrate a white solid product precipitated and was separated and found to have a melting temperature of 89°-93° C.
The so-prepared 4-((5-(trifluoromethyl)-2-pyridinyl)-thio)phenol (10 gms., 0.037 moles) was dissolved in 80 ml of dimethylsulfoxide and dry powdered sodium hydroxide (6.7 gm., 0.37 moles) was added. The mixture was warmed to about 40° and stirred until the base was all in solution indicating that the desired sodium phenate had formed. Ethyl bromopropionate (6.7 gm., 0.37 moles) was then added all at once. The reaction was run at 100°-105° for 2.0 hours, then cooled and poured into 450 ml of cold water. The ester was extracted into methylene chloride, the extract dried and solvent removed leaving the product as an oil weighing 13.5 gm.
This was used without further purification for the next step which was hydrolysis of the ester to the metal salt in aqueous alkaline medium.
The ethyl-2-(4-((5-trifluoromethyl)-2-pyridinyl)thio)phenoxy)propionate (13.5 gm., 0.37 moles) was dissolved in 50 ml of 95% ethanol and a solution of sodium hydroxide (3.0 gm., .075 moles) in 25 ml of water was added. The mixture was refluxed at 80° for about 6.0 minutes then cooled, poured into 400 ml of cold water and extracted with 250 ml of methylene chloride to remove any base insoluble impurities. The aqueous solution containing the sodium salt of the acid was acidified to pH 1 with concentrated hydrochloric acid. The product which precipitated as a gummy solid was washed with water (after decanting) and taken up in hot methylcyclohexane. On cooling the product precipitated as white crystals having a melting temperature of 118°-120° C. and a composition of, by weight, 52.38% carbon; 3.66% hydrogen; 4.00% nitrogen and 9.07% sulfur. The theoretical composition of 2-(4-((5-trifluoromethyl)-2-pyridinyl)thio)phenoxy)propanoic acid is 52.5% carbon; 3.5% hydrogen; 4.08% nitrogen and 9.34% sulfur.
EXAMPLE 13
4-Mercaptophenol (6.4 gm., 0.051 moles) was dissolved in 70 ml of dimethylsulfoxide and a solution of sodium hydroxide (2.04 gm., 0.051 moles) in a 3.0 ml of water was added. The mixture was warmed to about 50° and stirred under nitrogen for 10 minutes to form the sodium thiophenate salt. A solution of 2,3-dichloro-5-(trifluoromethyl)pyridine (11.0 gm., 0.051 moles) in 60 ml of dimethylsulfoxide was next added all at once. The mixture was then heated at 95°-100° for 2.5 hours. At the end of this time it was poured into 500 ml of cold water and allowed to stand for 45 minutes. The solid was then collected on a filter, washed and taken up in about one liter of boiling hexane. The product precipitated on cooling as a white solid melting at 94°-96° C.
The so-prepared 4-((3-chloro-5-(trifluoromethyl)-2-pyridinyl)thio)phenol (11.0 gm., .036 moles) was dissolved in 80 ml of dimethylsulfoxide and dry powdered sodium hydroxide (1.44 gm., 0.036 moles) was added. The mixture was warmed and stirred until the base was all in solution showing that the desired sodium phenate had formed. Ethyl bromopropionate (6.5 gm., 0.036 moles) was then added all at once. The reaction was run at 100° for 2.0 hours then cooled and poured into 500 ml of water. Most of the product precipitated as a white semi-solid. The aqueous layer which was decanted off was extracted with 300 ml of methylene chloride. The extract was separated, solvent removed and the residue added to the main product. This was washed thoroughly with water to remove residual dimethylsulfoxide and used without further purification for the hydrolysis step.
The so-prepared ethyl-2-(4-((3-chloro-5 (trifluoromethyl)-2 pyridinyl)thio)phenoxy)propionate (14.6 gm., .036 moles) was dissolved in 60 ml of 95% ethanol and a solution of sodium hydroxide (2.9 gm., 0.072 moles) in 25 ml of water was added. The mixture was heated at reflux for about 4 minutes, then cooled and poured into 400 ml of water. The solution was acidified to pH 1 with concentrated hydrochloric acid which precipitated the product as a sticky solid. This was taken up in a boiling mixture of hexane and methyl cyclohexane. After drying, filtering and cooling, the white crystalline product separated and was collected on a filter and exhibited a melting temperature of 132°-134° C. and was found to contain, by weight, 47.64% carbon; 3.14% hydrogen; 3.51% nitrogen; 9.25% chlorine and 8.44% sulfur. The theoretical composition of 2-(4-((3-chloro-5-trifluoromethyl)-2-pyridinyl)thiophenoxy)propanoic acid is 47.69% carbon; 2.93% hydrogen; 3.70% nitrogen; 9.38% chlorine and 8.48% sulfur.
EXAMPLE 14
Ninety ml of thionyl chloride were added to 9.0 g of 2-(4-((3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid and the mixture was refluxed for 34 minutes. The excess thionyl chloride was removed on a still and the resulting acid chloride was put in solution in 30 ml of benzene. This was added to a reaction flask containing 2.1 g methoxy amine hydrochloride in 20 ml of benzene plus a solution of 3.8 g of potassium carbonate in 31/2 ml of water. The reaction mixture was then refluxed for 2 hours. The salt was filtered off and the volatiles removed on the rotary evaporator. The crude solids were taken up in heptane and crystallized. From this 6.75 g of white solid were obtained which had a melting point of 135°-6° C. and an elemental analysis of, by weight: C=48.98%; H=3.69%; N=7.16%; and Cl=8.90%. The theoretical composition of 2-(4-((3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy) phenoxy)-N-methoxy-propanamide is C =49.18%; H =3.61%; N =7.17%; and Cl =9.07%.
EXAMPLE 15
Sixty ml of thionyl chloride were added to 6.0 g of 2-(4-(3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy) propanoic acid and the mixture was refluxed for 30 minutes. The excess thionyl chloride was removed on a still using aspirator vacuum. The resulting acid chloride was put in solution in 25 ml toluene. This solution was then added to a reaction flask containing 2.1 g butoxy ethanol (DOWANOL EB®), 1.85 g triethyl amine and 27 ml toluene and the mixture refluxed for about 2 hours. The salt was filtered off and the volatiles removed on a rotary evaporator. The crude product was taken up in n-hexane, purified with norite activated carbon and the hexane removed on the rotary evaporator. 7.05 g of amber oil were obtained which had a refractive index of 1.5061 at 25° C. and an elemental analysis of: C=54.27%; H=4.97%; N=3.21%; and Cl=7.77%. Calculated values for 2-(4-((3-chloro-5 (trifluoromethyl)-2-pyridinyl)oxy)phenoxy)-propanoic acid, 2-butoxyethyl ester are: C=54.61%; H=5.02%; N=3.03%; and Cl=7.68%.
EXAMPLE 16
Eighty ml of thionyl chloride were added to 8.0 g of 2-(4-(3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy) propanoic acid and the mixture was refluxed for 38 minutes. The excess thionyl chloride was then removed on a still using aspirator vacuum. The resulting acid chloride was put into solution in 30 ml toluene. This solution was then added to a reaction flask containing 2.1 g of butyl mercaptan, 2.5 g of triethyl amine and 25 ml of toluene. The mixture was slowly heated to 98° C. over a one hour period and then taken to reflux and refluxed for about 45-50 minutes. The salt was filtered out and the volatiles removed on a rotary evaporator. The crude product was taken up in n-hexane, purified with norite activated carbon and the hexane removed on the rotary evaporator. The resulting 9.1 g of amber oil and a refractive index of 1.5330 at 25° C. and an elemental analysis of: C=52.39%; H=4.46%; N=3.32%; Cl=8.08%; and S=7.1%. The theoretical composition for 2-(4-((3-chloro-5 (trifluoromethyl)-2-pyridinyl)oxy)phenoxy) propanoic acid-S-butyl ester is: C=52.59%; H=4.41%; N=3.23%; Cl=8.17%; and S=7.39%.
The compounds of the present invention have been found to be suitable for use in methods for the pre and postemergent control of annual and perennial grassy weeds. The active ingredients of the present invention have been found to have advantage over prior art compounds in the control of perennial grassy weeds in that the present compounds control a broader spectrum of such weeds than the counterpart compounds while exhibiting a higher level of activity or control at like dosage rates. In addition, the present compounds are sufficiently tolerant towards most broad leafed crops to contemplate control of grassy weeds therein at substantially commercially practicable levels, particularly so with the preferred compounds.
For all such uses, unmodified active ingredients of the present invention can be employed. However, the present invention embraces the use of a herbicidally-effective amount of the active ingredients in composition form with an inert material known in the art as an adjuvant or carrier in solid or liquid form. Thus, for example, an active ingredient can be dispersed on a finely-divided solid and employed therein as a dust. Also, the active ingredients, as liquid concentrates or solid compositions comprising one or more of the active ingredients can be dispersed in water, typically with aid of a wetting agent, and the resulting aqueous dispersion employed as a spray. In other procedures, the active ingredients can be employed as a constituent of organic liquid compositions, oil-in-water and water-in-oil emulsions or water dispersions, with or without the addition of wetting, dispersing, or emulsifying agents.
Suitable adjuvants of the foregoing type are well known to those skilled in the art. The methods of applying the solid or liquid herbicidal formulations similarly are well known to the skilled artisan.
As organic solvents used as extending agents there can be employed, e.g., benzene, toluene, xylene, kerosene, diesel fuel, fuel oil, and petroleum naptha, ketones such as acetone, methylethyl ketone and cyclohexanone, chlorinated hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and perchloroethylene, esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g., ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, alcohols, e.g., methanol, ethanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, butylcarbitol acetate and glycerine. Mixtures of water and organic solvents, either as emulsions or solutions, can be employed.
The active ingredients can also be applied as aerosols, e.g., by dispersing them by means of a compressed gas such as one of the hydrocarbon successors to the fluorocarbons which are shortly to be banned.
The active ingredients of the present invention can also be applied with solid adjuvants or carriers such as talc, pyrophyllite, synthetic fine silica, attapulgus clay, kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, Fuller's earth, cotton seed hulls, wheat flour, soybean flour, pumice, tripoli, wood flour, walnut shell flour, redwood flour and lignin.
As stated, it is frequently desirable to incorporate a surface-active agent in the compositions of the present invention. Such surface-active or wetting agents are advantageously employed in both the solid and liquid compositions. The surface-active agent can be anionic, cationic or nonionic in character.
Typical classes of surface-active agents in clude alkyl sulfonate salts, alkylaryl sulfonate salts, alkylaryl polyether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long-chain mercaptans and alkylene oxides. Typical examples of such surface-active agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkyl phenol ethylene oxide condensation products, e.g., p-isooctylphenol condensed with 10 ethylene oxide units, soaps, e.g., sodium stearate and potassium oleate, sodium salt of propylnaphthalene sulfonic acid, di(2-ethylhexyl)ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium decane sulfonate, sodium salt of the sulfonated monoglyceride of coconut fatty acids, sorbitan sesquioleate, lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene glycol esters of fatty acids and rosin acids, e.g., Ethofat 7 and 13, sodium N-methyl-N-oleyl taurate, Turkey Red Oil, sodium dibutylnaphthalene sulfonate, sodium lignin sulfonate, polyethylene glycol stearate, sodium dodecyl benzene sulfonate, tertiary dodecyl polyethylene glycol thioether (nonionic 218), long-chain ethylene oxide-propylene oxide condensation products, e.g., Pluronic 61 (molecular weight about 1000), polyethylene glycol ester of tall oil acids, sodium octophenoxyethoxyethyl sulfate, tris(polyoxyethylene)sorbitan monostearate (Tween 60), and sodium dihexylsulfosuccinate.
The concentration of the active ingredients in solid or liquid compositions generally is from about 0.003 to about 95 percent by weight or more. Concentrations from about 0.05 to about 50 percent by weight are often employed. In compositions to be employed as concentrates, the active ingredient can be present in a concentration from about 5 to about 98 weight percent. The active ingredient compositions can also contain other compatible additaments, for example, phytotoxicants, plant growth regulants, pesticides and the like and can be formulated with solid particulate fertilizer carriers such as ammonium nitrate, urea and the like.
The present compositions can be applied by the use of power dusters, boom and hand sprayers, spray dusters, by addition to irrigation water, and by other conventional means. The compositions can also be applied from airplanes as a dust or a spray since the active ingredients are effective at very low application rates.
The active ingredients of the present invention including methyl 2-((4-(5-trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoate; 2-((4-(5-(trifluoromethyl)-3-chloro-2-pyridinyl)oxy)phenoxy)propionamide; 2-((4-(5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxypropanoic acid and salts thereof according to the present invention; butyl 2-((4-(5-trifluoromethyl)-3-chloro-2-pyridinyl)oxy)phenoxypropanoate; 2-((4-(5-trifluoromethyl)-2-pyridinyl) oxy)phenoxy)propionamide N-methyl 2-((4-(5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanomide and 2-(4-((3-chloro-5-trifluoromethyl-2-pyridinyl)thio)phenoxy propanoic acid have been found to possess desirable herbicidal activity in general against grassy weeds such as foxtail, barnyard grass, wild oats and crabgrass in preemergent operations and also against the same grasses and particularly seedling Johnson grass in postemergent operations. These compounds possess unique activity in being effective in the control broadly of all or most of Johnson grass, quack grass, bermuda grass, orchard grass, Dallis grass and cogon grass, all perennial grassy weeds, while being tolerant to fairly tolerant to broadleaf crops such as cotton and soybeans.
The active ingredients of the present invention including the compounds just above listed have been found to possess particularly desirable herbicidal activity against wild oats, foxtail, barnyard grass, crabgrass and seedling Johnson grass in postemergent operations, as well as desirable broad spectrum activity against the perennial grassy weeds listed above and at lower dosage rates than the substituted propanoates and propanols of the prior art while showing a greater tolerance to broad leaf crops.
The present compounds which are substituted propanols or propyl ethers are more effective in preemergent operations than in postemergent applications.
The exact rate to be applied is dependent not only on a specific active ingredient being applied, but also on a particular action desired (e.g., general or selective control), the plant species to be modified and the stage of growth thereof as well as the part of the plant to be contacted with the toxic active ingredient. Thus, it is to be understood that all of the active ingredients of the present invention and compositions containing the same may not be equally effective at similar concentrations or against the same plant species. In non-selective preemergence and foliar treatments, the active ingredients of the invention are usually applied at an approximate rate of from about 0.5 to about 5 pounds/acre, but lower or higher rates may be appropriate in some cases such as 0.01 to about 20 pounds/acre or more. In preemergent operations for selective uses a dosage of about 0.05 to about 20 pounds/acre or more is generally applicable, a rate of 0.2 to 4 pounds/acre being preferred and about 0.75 to about 1 pound/acre being most preferred.
In selective postemergent operations a dosage of about 0.01 to about 20 pounds/acre or more is generally applicable, although not all compounds are equally effective and some weeds are more difficult to control. Thus, a dosage rate in the range of about 0.05 to about 0.75 pounds/acre is preferred in postemergent control of annual grassy weeds, while about 0.5 to about 5 pounds/acre is a preferred dosage range for the postemergent control of perennial grassy weeds.
In view of the foregoing and following disclosures, one skilled in the art can readily determine the optimum rate to be applied in any particular case.
EXAMPLES 17-40
In representative operations, each compound to be utilized in a series of tests is dissolved in acetone to one half of the final volume (twice the final concentration) to be used and the acetone solution in each case is admixed with an equal volume of water containing 0.1 percent by weight of Tween-20 surface active material (Tween 20 is a trademark of Atlas Chemical Company). Each compound is selected from a group consisting of compounds according to the invention. The compositions, generally in the nature of an emulsion, were employed to treat separate respective seed beds of sandy loam soil of good nutrient content wherein each seed bed contained separate groups of a known number of good viable seeds, each group being of one of a predetermined plant species. The various beds were positioned side by side and exposed to substantially identical conditions of temperature and light. Each bed was maintained so as to prevent any interaction with test compounds in different seed beds. Each seed bed was treated with one of the compositions as a soil drench applied at one of two predetermined rates to deposit a predetermined amount of a given test compound uniformly throughout the surface of the bed. The compositions were applied to the seed beds so that different seed beds of a given plant species were treated with one of each of the test compounds. Another seed bed was treated only with water to serve as a control. After treatment, the seed beds were maintained for two weeks under greenhouse conditions conducive for good plant growth and watered as necessary. The specific plant species, test compound and dosage and the percent preemergent control obtained are set forth in the table below. Control refers to the reduction in growth compared to the observed results of the same species.
__________________________________________________________________________PREEMERGENCE CONTROL OF PLANT SPECIES ##STR19## Plant Species Barn-Compound Tested Dosage In Wild Fox- yard Crab- JohnsonX Y Z T Lbs Per Acre Corn Rice Wheat Oats tail Grass grass Grass__________________________________________________________________________Cl CF.sub.3 CN O 1 95 70 0 40 100 95 100 100 .25 40 0 0 0 95 0 40 70CF.sub.3 -- ##STR20## O 0.5 0.125 0.063 100 100 60 100 100 100 100 100 100 100 98 60 100 100 90 100 100 98Cl CF.sub.3 ##STR21## O 1 0.25 100 60 90 100 100 100 100 60 100 100 100 80CF.sub.3 Cl ##STR22## O 0.5 .125 100 80 98 100 70 100 100 99 100 100 100 80CF.sub.3 -- ##STR23## O 0.5 .125 100 95 100 100 100 100 100 100 100 100 100 95CF.sub.3 CF.sub.3 CN O 10 -- -- -- 40 95 100 100 --CF.sub.3 -- ##STR24## O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR25## S 0.125 .063 100 98 100 100 30 95 95 100 100 100 100 97 97Cl CF.sub.3 ##STR26## O 1 .25 100 60 98 40 -- 90 100 100 100 100 90 90CF.sub.3 CF.sub.3 ##STR27## O 1 .25 70 0 0 -- 60 90 80 60 0 100 90 60CF.sub.3 -- ##STR28## O 1 .25 70 0 95 98 90 100 60 0 100 90 60CF.sub.3 -- CN O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl CN O 10 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 ##STR29## O 10 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 CH.sub.2 OH O 10 -- -- -- 90 98 98 --CF.sub.3 Cl CH.sub.2 OH O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR30## O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR31## O 10 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 ##STR32## O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR33## O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR34## O 10 -- -- -- 100 100 100 100 --Cl CF.sub.3 ##STR35## O 10 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 ##STR36## O 10 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR37## O 10 -- -- -- 100 100 100 100 --CF.sub.3 -- ##STR38## O 10 -- -- -- 100 100 100 100 --__________________________________________________________________________
EXAMPLES 42-65
So as to illustrate clearly the phytotoxic properties of the various active ingredients of the present invention applied postemergently, a group of controlled greenhouse experiments is described below.
Various species of plants were planted in beds of good agricultural soil in a greenhouse. After the . plants had emerged and grown to a height of about 2-6 inches a portion of the plants were sprayed with an aqueous mixture, made by mixing a selected active ingredient and emulsifier or dispersant with about 1:1 water -acetone, employing sufficient amounts of the treating composition to provide application rates of 4000 parts per million (ppm) or about 10 pounds per acre and in some cases at lower rates. Other portions of the plants were left untreated to serve as controls.
After a period of 2 weeks, the effect of the respective test ingredients used on respective groups of plants was evaluated by a comparison with the control groups of the plants. The results are tabulated in the following table.
__________________________________________________________________________POSTEMERGENCE CONTROL OF PLANT SPECIES ##STR39## Plant Species Barn-Compound Tested Wild Fox- yard Crab- JohnsonX Y Z T Dosage in PPM Corn Rice Wheat Oats tail Grass grass Grass__________________________________________________________________________Cl CF.sub.3 ##STR40## O 500 125 100 80 0 -- 40 0 100 80 100 98 100 100 100 100 98CF.sub.3 Cl ##STR41## O 125 31.5 95 70 98 90 40 20 70 70 100 98 80 100 100 100 100CF.sub.3 Cl ##STR42## O 62.5 15.6 100 100 80 80 60 60 80 98 100 98 100 100 100 100 100CF.sub.3 Cl ##STR43## O 62.5 15.6 100 100 90 30 95 60 100 -- 100 95 100 100 100 100 100CF.sub.3 -- ##STR44## O 62.5 15.6 95 95 -- -- 60 40 100 20 100 60 90 100 100 98CF.sub.3 -- ##STR45## O 62.5 15.6 100 80 70 40 50 30 80 10 90 90 70 98 100 95Cl CF.sub.3 ##STR46## O 500 60 0 0 0 0 0 60 100CF.sub.3 Cl ##STR47## O 62.5 15.6 80 60 99 60 90 80 98 90 90 80 90 98 100 100CF.sub.3 CF.sub.3 CN O 4000 -- -- -- 100 90 100 100 --Cl CF.sub.3 CN O 4000 -- -- -- -- 80 60 100 --Cl CF.sub.3 ##STR48## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 -- ##STR49## O 4000 -- -- -- -- 100 100 100 --CF.sub.3 -- CN O 4000 -- -- -- 100 100 100 100 --CF.sub.3 Cl CN O 4000 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.F.sbsb.3 ##STR50## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 CH.sub.2 OH O 4000 -- -- -- 95 95 70 98 --CF.sub.3 Cl CH.sub.2 OH O 4000 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR51## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR52## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 ##STR53## O 4000 -- -- -- 99 100 100 100 --CF.sub.3 Cl ##STR54## O 4000 -- -- -- 100 98 100 100 --Cl CF.sub.3 ##STR55## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 CF.sub.3 ##STR56## O 4000 -- -- -- 100 100 100 100 --CF.sub.3 Cl ##STR57## S 28 14 7 100 30 0 20 *-- -- -- 60 0 -- 100 100 80 100 100 100 100 100__________________________________________________________________________ *Wheat was not run at these lower dosage rates as control at 111 ppm was only 20% and at 55.5 ppm control was zero. Approximate pounds per acre application equivalent to ppm dosage rates ar as follows: 111 ppm = 0.2 lbs/A; 55.5 ppm = 0.1 lb; 28 ppm = 0.05 lb; 14 ppm = 0.025 lb; 7 ppm = 0.013 lb/A.
EXAMPLES 66-77
In a series of tests clearly demonstrating the herbicidal properties of the compounds of the present inven tion applied postemergently, various metal and amine salts of propanoic acids prepared in aqueous solution as described hereinabove and brought initially to a dilution of 4,000 ppm were applied to growing plants under greenhouse conditions.
Various species of plants were planted in a series of pots containing good agricultural soil in a greenhouse. After some of the plants had emerged and grown to a height of about 2-6 inches some of the plants were sprayed, respectively, with a respective one of the said aqueous solutions, then diluted and sprayed on other respective selected plants at lower rates, each species of plant not being run at all rates. Other plants were left untreated to serve as controls. Still other plants, plants of Bermuda grass, blue grass, Johnson grass and cheat grass, were allowed to grow to 6-8 inches then four times cut back to 2 inches and allowed to regrow, all over about a 6-7 week period providing established plants.
After a period of about two weeks, the effect of the respective test ingredients used on various respective plants was evaluated by comparison with the control group of plants. The results showed that the potassium and triethylamine salts of 2-((4-(5-(trifluoromethyl)-3-chloro-2-pyridinyl)oxy)phenoxy)propanoic acid applied (a) at a rate of 4,000 ppm gave complete control of Bermuda grass, sorghum and barnyard grass while showing little or no control of cotton; (b) at a rate of 2,000 ppm gave substantial to complete control of bluegrass and rice while showing no effect on soybeans; (c) at a rate of 1,000 ppm gave complete control of Johnson grass, crabgrass and yellow foxtail; and (d) at a rate of 500 ppm exhibited complete control of cheat grass, corn, wheat and wild oats.
In addition, the ethanolamine and sodium salts of 2-4((-(5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid applied (a) at a rate of 4,000 ppm gave complete control of Bermuda grass, sorghum and barnyard grass while showing no adverse effects on cotton; (b) at a rate of 2,000 ppm gave 70% control of bluegrass and complete control of rice while having no adverse effects on soybeans; (c) at a rate of 1,000 ppm showed complete control of Johnson grass and crab grass and fair to excellent control of yellow foxtail; and (d) at a rate of 500 ppm gave complete control of cheat grass, corn, wheat and wild oats.
Further the ethylamine salt of 2-((4-(5-chloro-3-trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid and the ammonium salt of 2-((4-(3,5-bis(trifluoromethyl)-2 -pyridinyl)oxy)phenoxy)propanoic acid gave nearly as good control of the same plants at the rates recited above as described for the salts rated in the preceding paragraphs.
The same salts applied in preemergent operations using the solutions described above as well as in Examples 6 and 7 and applied at rates in the range of about 10 to about 1.25 pounds per acre in a manner similar to that described for Examples 17-41 showed substantially complete to complete control of crabgrass, yellow foxtail, barnyard grass, wild oats and wheat and no control of cotton velvet leaf or annual morning glory at the higher rates and the same or substantially the same excellent control at the lower rates.
EXAMPLES 78-79
In preemergent operations carried out in a manner similar to that described in Examples 17-41, using 10 poundsacre of active ingredient, N,N-di-n butyl 2-((4-(3,5-bis(trifluoromethyl)-2-pyridinyl)oxy)phenoxy propanamide gave 60 percent control of crabgrass, but no control of wild oats, foxtail, barnyard grass, cotton, pigweed, annual morning glory or velvet leaf, while N,N-dimethyl 2-((4-(5-trifluoromethyl-2-pyridinyl)oxy)phenoxy)propanamide showed complete control of wild oats, foxtail, barnyard grass and crabgrass.
In postemergent operations carried out in the same manner as that described in Examples 42-65, applying active ingredient at the rate of 4,000 ppm, the above described N,N-di-n-butyl propanamide showed 80 percent control of cotton and 60 percent control of velvet leaf but no control of wild oats, foxtail, barnyard grass, crabgrass or annual morning glory, while the above identified N,N-dimethyl propanamide exhibited complete control of wild oats, foxtail, barnyard grass and crabgrass.
|
Novel compounds used as intermediates for making herbicides are disclosed. The novel compounds include acid chlorides of 2-(4-((3-chloro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid and 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propionic acid.
| 2
|
This application is a continuation-in-part of application Ser. No. 864,016 filed May 16, 1986 now abandoned.
BACKGROUND OF THE INVENTION
There are times when a mother, father or parent caring for or attending to a baby, child, infant or toddler must visit public areas or rooms such as a rest room to attend to her or his needs or that of the infant, or even for purposes of changing a diaper. Experience has proven that this may be inconvenient, frustrating, and the individual may be unable to do so because of the inability to place the child with an individual other than a stranger, or secure the child safely and within view of the parent while attending to his or her needs. Public places normally do not have facilities which will permit a parent to place a child safely under his or her watchful eye while attending to his or her needs. If the child is placed in the hands or custody of a stranger, there is always the danger of kidnaping, child abuse, or harm coming to the child. Accordingly, there exists a need for the safe securement of children within public areas by parents while attending to the need of parent or child or both.
SUMMARY OF THE INVENTION
A principal object of this invention is to provide an assembly that may be installed in a public place or room such as a rest room cubicle that may be clasped or unfolded from a substantially flat condition or state against a door or wall, and may be thereafter erected or folded in a relatively easy and convenient manner to form a changing table for a child, and further folded to erect a seat for the infant in which the child may be secured while the parent attends to his or her needs while maintaining a watchful eye over the child at the same time.
Another object is to provide an assembly of the foregoing type which may be erected and collapsed into a flat condition relatively easily and without any great degree of manual dexterity, and even with one hand while the parent holds the child in the other.
A further object is to provide assembly of the foregoing type which may be easily constructed of relatively few and inexpensive parts and with mass-production techniques which would enable the assembly to be made and marketed at relatively low cost.
Other objects and advantages will become apparent in the following detailed description, which is to be taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view with certain parts broken away, removed and sectioned illustrating a public space or room, more specifically, a bathroom cubicle in which the infant wall seat and changing table assembly of the present invention is mounted and shown in a collapsed and relatively flat condition.
FIG. 2 is a front view thereof.
FIG. 3 is a rear view thereof.
FIG. 4 is side view thereof, with certain parts broken away and removed, and also showing a phantom of the assembly erected as a changing table.
FIG. 5 is a side view showing the assembly erected in the position in which it may be deployed or used as a changing table.
FIG. 6 is a bottom view thereof with the drop-leaf also shown in phantom when shifted to the folded or seat-forming position.
FIG. 7 is front view of the assembly in the changing table position.
FIG. 8 is a prespective view showing the assembly being folded from the changing table position to the seat position.
FIG. 9 is a perspective view with the assembly completely folded and erected to the seat position.
FIG. 10 is a rear perspective view of the assembly of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, a contemplated public space such as a bathroom cubicle 20 is shown in which is hung or suitably supported, the infant wall seat and changing table are assembly 22 of the present invention. This assembly 22 is shown in the collapsed or unfolded position in which it is somewhat flush against the wall or door of the cubicle, which may be of any suitable construction for such purposes whether it be of wood, metal, plaster, drywall, etc. In this connection, the anchors or supports 24 are suitably connected to connect or anchor the assembly 22. These supports 24 extend through the vertical posts or members 26 to which is fixed the chair back panel 28. A seat panel 30 is hingedly connected to the vertical back panel 28. At each side of the seat panel 30 is pivotally mounted a drop leaf 32A, 32B which, in view of their location, are of complementary construction. Toward this end, and with a specific reference to drop leaf 32A, bottom panel 34A is directly hinged to the seat panel 30. This bottom panel 32A has a drop leaf support 36A fixed thereto and which is adapted to engage with the bottom surface of the seat panel 30 to support the drop leaf in the outwardly extending unfolded position when the seat panel 30 is pivoted to its horizontal position as shown in FIG. 7. A side railing 38A and front railing 40A are advantageously provided to prevent the child from falling out of the assembly when folded to its changing table position shown in FIG. 7. When each drop leaf is pivoted to permit the front rail 40A to rest upon the seat panel 30 as shown in FIG. 8, the child is contained in the assembly when folded to the erect infant wall seat position shown in FIG. 9. In this regard, the drop leafs are maintained in the position shown in FIG. 9 through the interconnection of a releasable latch which may assume any one of many constructions and configurations as for example, that shown in the figures which includes a rearwardly extending pin which is adapted to be forcibly placed in an accommodating recess 44A of bracket 46A secured to the vertical post 26A.
Interconnecting the back panel 28 and the seat panel 30 to permit it to assume the fully collapsed or extended position of FIG. 1 and to permit the seat to be pivoted to its horizontal position and maintained in this position until it is desired to shift it back down to the unfolded position, is a releasable drop leaf bracket assembly 50. This bracket assembly includes a pair of spring-biased hinges 52A and 52B. Referring specifically to the hinge 52A, an upper shorter arm 54A is pivoted to the bottom of seat panel 30 at one end and at the other end pivoted to a longer arm 56A which in turn is pivoted to the lower end of the vertical post 26A. A spring 58A extends between and biases each of the arms 54A and 56A. In the position shown in FIG. 5, the edge 60A of upper arm 54A abuts against edge 62A of lower arm 56A and these edges are biased into this abutting relationship at which arms 54A and 56A are aligned by means of the interposed spring 58A. In this manner, the horizontal position of the seat panel 30 is maintained. A pipe 64 extends between each hinge 52A and 52B and is secured thereto in order that each hinge will act in unison by means of the bracket 66A secured to the end of the lower arm 56A. A handle 68 of any convenient configuration extends from the pipe 64 and permits the seat panel 30 to be shifted conveniently between the horizontal erect position of FIG. 5 and the vertical unfolded position of FIGS. 1 and 4.
When the assembly 22 is in the fully erect infant wall seat position of FIG. 9 or in the changing table position of FIG. 7, the child may be secured in place without danger of falling by means of the strap 70 which may assume any one of many constructions which would permit it to be secured to the seat panel 30, buckled and unbuckled to permit the child to be placed in the secured position and removed therefrom.
In operation and assuming that the infant wall seat and changing table assembly 22 is in the folded vertical position of FIGS. 1 to 4, a parent desiring to place a child on a changing table for purposes of changing a diaper will grasp the seat panel 30 with one hand and pivot it or shift it vertically to the position of FIGS. 5, 6 and 7 at which the hinges pivot about each of their pivot points to place the abutting edges 60A of shorter arm 54A and edge 62A of longer arm 56A into abutting relationship and biased against one another by means of the interposed spring. In this position, the seat 30 will remain in a horizontal position until it is deliberately shifted downwardly therefrom by means of a pull downwardly by the parent on handle 68. When changing the infant's diaper, the parent may strap the child in place by means of the strap 70.
Should the parent wish to place the assembly 22 into the infant wall seat position, when the seat panel 30 is secured or locked into its horizontal position as shown in FIGS. 5, 6 and 7, the drop leafs 32A and 32B are pivoted inwardly from the position shown in FIG. 7 to that depicted in FIGS. 8 and 9. These drop leafs 32A and 32B are secured in their vertical or wall seat position by means of the selected latch assembly which in the specific disclosed embodiment is the latching of pin 42A in recess 42B of the bracket 46B. In this position, the child may be secured in place by utilizing the strap 70. When this has been accomplished, the parent may then attend to his or her needs in the public room or space whether it be a bathroom or other location.
When the parent has attended to his or her specific needs and wishes to remove the child from the assembly 22, the strap 70 is unbuckled, and the child is removed. On the other hand, should the parent wish to attend to other needs of the child, for example, changing a diaper, the drop leafs 32A and 32B may be unlatched and placed in their horizontal extended position as shown in FIGS. 5, 6 and 7. In the event the parent does not wish to utilize the assembly 22 in the changing table position, the seat panel 30 is shifted downwardly to the vertical collapsed position of FIGS. 1 to 4 simply pulling downwardly on the handle 68.
It should be understood that the back panel 28 may in fact be a vertical wall or partition on the public space or enclosure as distinct from being a separate member that is attached thereto.
The parts of the assembly 22, particularly the panel and rails, may be formed of any suitable resin material that lends itself to extrusion or molding techniques. The resin should have the ability and property of being readily cleaned and durable in nature considering the intended use, and not readily deteriorated by liquids or body wastes to which it may be subjected. Obviously metal or wood can also be used or a combination of all of these materials.
In addition, although the foregoing description is specific to the placement and mounting of the assembly 22 in public places, it should be understood that the assembly 22 may also be placed at other locations including places of public transportation, homes, etc.
Thus, the several afore-noted objects and advantages of the invention are most effectively attained. Although a single somewhat preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that it is in no sense limited thereby, and its scope is to be determined by that of the appended claims.
|
An infant wall seat and changing table assembly is foldable between a substantially flat condition against a vertical support and a horizontal position at which it forms a changing table for the child. The assembly is further folded to form a seat for the child with constraints for maintaining the child therein. The assembly may then be returned to either the changing table position or its flat vertical position.
| 8
|
BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to computer means for collecting data, storing data, reviewing data, and organizing data for the purposes of collecting data pertaining to clinical trials. More particularly, this invention relates to a remote collection unit that allows operators the ability to electronically gather data from multiple locations, validate and verify the collected data, automatically recheck out-of-range data, call up procedural information, and to electronically transfer the collected data to a main computer system for consolidation and analysis. In addition, this invention discloses a method by which details pertaining to the clinical trial protocol studies can be defined and stored in a persistent design repository, then transmitted to the remote control units as either new protocol studies, or updates to existing protocol studies.
[0003] 2. Brief Description of the Prior Art
[0004] Typical data collection techniques start with a detailed definition of the procedures and business rules which determine which data are needed to fulfill the business purposes. In the case of the health care industry, the procedures and business rules are influenced or even defined by the Food and Drug Administration (FDA). The Federal regulations governing electronic records in clinical trials (21 CFR Part 11) were issued on March 1997. Randomized controlled clinical trials are the preferred method for evaluating medical interventions. The use of outdated paper-based processes is a major contributor to the cost and significant length of time associated with clinical trials.
[0005] In a paper-based data collection process, at each investigative center of a multicenter trial, clinical investigators observe the test subjects and their observations are recorded on source documents (medical records). Then Clinical Research Coordinators (CRCs) fill out paper Case Report Forms (CRFs) based on the source documents. The CRFs are then taken to the coordinating center by a clinical research associate (CRA), where they are entered into a central database using redundant data entry techniques. There, the data undergo validation and quality control checks. For audit purposes, each investigative site must maintain archived copies of the CRFs, as well as archives of the source documents. The inefficiency in the data capture process can be seen in the fact that trial data is kept on paper forms until the final data entry step. Research coordinators and investigative sites must record observations on paper forms. There are delays before the paper forms arrive at the coordinating site. Problems in the data are not flagged until data entry time and can only be corrected at significant effort and cost. In addition, the investigative sites are required to archive the paper forms separately from the central trial database to enable future data quality audits.
[0006] Web-based data capture is one alternative to paper based data capture. Instead of sending paper CRFs to the coordinating site, the CRCs key data directly into the trial database using browsers connected over the Internet. This approach allows data to be validated much closer to the point of observation and much earlier in the trial process. A key flaw in these web-based data capture systems is the change of workflow required to adopt them. In the paper-based process, CRCs can complete paper CRFs while interacting with patients. In the web-based process, CRCs must complete the web-based CRFs at a data entry terminal that is typically separate from patient care areas. Thus, the benefits of early data capture and validation are attenuated by the need to retrain CRCs and the fact that the patients and the data entry terminals are in different locations. A second flaw in web-based data capture systems is that investigative sites are still required to maintain paper CRF archives, providing no cost incentive for the investigative sites to adopt web-based technology.
[0007] Other computers systems have been disclosed that basically provide methods and apparatus for clinical trial related data capture. U.S. Pat. No. 6,566,999 issued to Kloos discloses a back-end clinical definition using a back-end clinical data management system (CDMS) where the back-end clinical definition is automatically converted into a Remote Data Entry (front-end) study definition. The front-end study definition is transferred to a remote computer hosting a front-end RDE product where it is used to regulate the acquisition of clinical data. During the back-end clinical definition to front-end study definition conversion process, a conversion map is created. The conversion map allows for the automated conversion of clinical data acquired using the front-end RDE product to a format that can be read by the back-end CDMS. Clinical data is retrieved from remote computers hosting a front-end RDE product in an automated manner without manual back-end clinical definition/front-end study definition conflict resolution.
[0008] Also see U.S. Pat. No. 6,496,827 issued to Kozam which discloses a centralized collection of geographically distributed data using a system which takes advantage of an interactive programming language, such as Java. TM and existing wide area networks, such as the Internet including the World Wide Web, to collect high quality data in an information center.
[0009] All the systems described have at least one of several major problems not present in the instant patent. One significant drawback is that the method of collecting data for introduction into the computer system is either via manual collection or via a non-portable computer. It is desirable for a plurality of Remote Collection Units running an embedded Target Application Binary that users could take out into the field to collect data. The second significant drawback is the method of updating the software on the Remote Collection Unit. The systems described above have fixed software definitions that are difficult to update. The Authoring Tool in the present invention generates Target Application Binaries based on the Study Protocol data stored in design repositories in persistent storage. The Target Application Binary is deployed to the Remote Collection Units, and can easily be updated as the Study Protocols and the resulting design repositories change or evolve over time. The third significant drawback is the reliance on third party commercial applications.
SUMMARY OF INVENTION
[0010] There is provided by this invention a data collection and monitoring system having a plurality of Remote Computer Units running Target Application Binaries which guide the users through procedural steps and data collection for a specified Study Protocol, and one or more or more centralized data repositories for the persistent storage of aggregated data collected by the Remote Collection Units. The Remote Collection Unit has a means to allow automatic transfer of the collected data via a Data Import and Export Module to a centralized data repository for further review, reporting, and distribution purposes. The present invention also discloses a Study Protocol Authoring Tool, which provides an interface for specifying the forms, business rules, and logic associated with a specific Study Protocol. The data associated with the Study Protocol is also stored in a centralized data repository, where it is used as input by a Generator to create Target Application Source Code, which is then processed by a Compiler to create a Target Application Binary, which is transferred to the Remote Collection Units and used to operate the data collection for the Study Protocol.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a basic block diagram of the computer system incorporating the principles of this invention;
[0012] FIG. 2 shows one output of the invention, the Target Application Binary;
[0013] FIG. 3 shows potential deployment scenarios supported by the invention;
[0014] FIG. 4 shows an object model of the Study Protocol Description data, drawn as a Class Diagram in the Unified Modeling Language.
DETAILED DESCRIPTION
[0015] FIG. 1 shows a block diagram of the invention. An Authoring Tool ( 10 a or 10 b ) located on any computing device is used to configure a description of the study protocol. The description describes information pertaining to the study protocol and can include, but is not limited to, the number and types of visits in the study, definitions of the forms that are to be filled out during each visit, validation and action rules for each field of each form, and how the fields of each form are grouped and displayed on screens in the destination platform.
[0016] When the Study Protocol Description ( 19 ) has been completed, the Authoring Tool ( 10 a , 10 b ) stores the Study Protocol Description ( 19 ) in the Design Repository ( 11 ), which is kept in persistent storage implemented in some structured form such as a relational database or structured document repository. Storage of the Study Protocol Description ( 19 ) in the Persistent Design Repository ( 11 ) enables the Study Protocol Description ( 19 ) to be modified and to evolve over time.
[0017] The Generator ( 12 ) utilizes the Study Protocol Description ( 19 ) stored in the Persistent Design Repository ( 11 ) to create the Target Application Source Code ( 13 ). The Target Application Source Code ( 13 ) is the source code for an application designed to collect and manage the data specified by the Study Protocol Description ( 19 ) defined above using the Authoring Tool ( 10 a , 10 b ) and stored in the Persistent Design Repository ( 11 ). The Target Application Source Code ( 13 ) utilizes APIs supplied by the destination platform, which can be one of a plurality of any type or combination of computing devices such as a server, a notebook computers, or a handheld computer. The program logic implemented in the Target Application Source Code is specific to the Study Protocol Description ( 19 ) defined above using the Authoring Tool ( 10 a , 10 b ) and stored in the Persistent Design Repository ( 11 ).
[0018] The Compiler ( 14 ) takes the Target Application Source Code ( 13 ) and compiles it into a Target Application Binary ( 15 ) for deployment on the destination platform. J2EE is one platform that can be utilized to implement the present invention. J2EE is designed for distributed, web-based applications running on web server and application server computers; it provides facilities for deploying applications as binary archives containing compiled Java class files. If the destination platform is J2EE, the present invention uses a Java compiler for J2EE to produce a J2EE web application packaged in a binary archive file. J2ME is another platform that can be utilized to implement the present invention. J2ME is designed for handheld computers with or without network connectivity. J2ME provides more limited programming libraries compared to J2EE, and also requires its binary archives to undergo security checking before being deployed on the handheld device. Moreover, J2ME's application deployment facilities are determined by the capabilities of the handheld computer; in particular, what kind of network connectivity is available on the device. If the destination platform is J2ME, the present invention uses a Java compiler and a byte code preverifier and emits a J2ME application packaged as a preverified archive file.
[0019] After the generation of the Target Application Binary ( 15 ), deployment may take place to any destination platform, including one or more servers ( 17 a , 17 b ), notebook computers ( 10 a , 10 b ), or Handheld Computers ( 16 ) using the standard deployment mechanisms for each destination platform. Each of the deployment mechanisms uses an interface means to communicate between the computer containing the Target Application Binary ( 15 ) and the destination platform. If the destination platform is a handheld computer running J2ME, the Target Application Binary ( 15 ) can be deployed to one or more of a plurality of J2ME Handheld Computers ( 16 a - 16 c ) utilizing an Interface Means ( 32 ) of either a wired or wireless network connection.
[0020] If the destination platform is a Server ( 17 a , 17 b ) running J2EE, the Target Application Binary ( 15 ) can be deployed to the Server ( 17 a , 17 b ) using the application deployment tools provided by the J2EE application server utilizing an Interface Means ( 30 ) of either a wired or wireless network connection. These management tools are typically used to upload the Target Application Binary ( 15 ) to the server and otherwise prepare it for execution on the server.
[0021] If the destination platform is a notebook computer ( 10 a , 10 b ) running J2ME or J2EE, the Target Application Binary ( 15 ) can be deployed to the notebook computer ( 10 a , 10 b ) utilizing an Interface Means ( 31 ) of either a wired or wireless network connection.
[0022] Once deployed to any destination platform, the Target Application Binary ( 15 ) can be used to collect clinical data via one or more of a plurality of J2ME Handheld Computers ( 16 a - 16 c ) or a web browser ( 18 ) located on any computer device to collect clinical data within the parameters set by the Study Protocol Description ( 19 ) defined above using the Authoring Tool ( 10 a , 10 b ) and stored in the Persistent Design Repository ( 11 ).
[0023] FIG. 2 shows one output of the present invention generated by the operation of the Target Application Binary ( 15 ) deployed on any destination platform. The figure assumes that the Target Application Binary ( 15 ) has already been deployed using the standard facilities available in each destination platform. The User ( 20 ), frequently a Clinical Research Coordinator, enters data into the Forms Module ( 22 ) implemented by the Target Application Binary ( 15 ) via the Input Means ( 40 ). The Input Means may take the form of an electronic stylus, keyboard, or any other data input mechanism supported by the destination platform on which the Target Application Binary ( 15 ) was deployed. The Forms Module ( 22 ) verifies that the data provided by the User ( 20 ) meets any validation criteria specified in the Study Protocol Description ( 19 ), which was defined using the Authoring Tool ( 10 a , 10 b ) and stored in the Persistent Design Repository ( 11 ).
[0024] Assuming the data are valid, the Forms Module ( 22 ) saves the data in the Data Repository ( 23 ). The Forms Module ( 22 ) also provides a mode where the User ( 20 ) may view and edit previously entered data. When the data are edited, the Data Repository ( 23 ) stores the edits as amendments to the original data in order to preserve a complete history and audit trail of the data.
[0025] Periodically, the User ( 20 ) invokes the Data Import and Export module ( 24 ) to upload the data to one or more of a plurality of centralized Data Repositories ( 25 a - 25 c ) utilizing an Interface Means ( 30 ) of either a wired or wireless network connection. Any individual Data Repository ( 25 a - 25 c ) might be managed by an investigative site (e.g. a research hospital or clinic) or by the sponsor of the clinical trial. The User ( 20 ) can also invoke the Data Import and Export module ( 24 ) to import data from other data repositories; for example, one or more of a plurality of site-managed or sponsor-managed data repositories ( 25 a - 25 c ), or another instance of the Target Application Binary running on one or more of a plurality of handheld computing devices ( 16 a - 16 c ).
[0026] FIG. 3 shows the range of deployment scenarios supported by the present invention. The present invention allows any number of target application binary instances to be running on any number of computers and to aggregate their data on one or more shared data depositories.
[0027] In the upper left corner of FIG. 3 , an instance of the Target Application Binary ( 15 a ) has been deployed on one of a plurality of web servers ( 17 a ) running an application platform such as J2EE. One or more from a plurality of computers running web browser clients ( 18 a - 18 b ) can collect and manage clinical data simultaneously. Periodically, the clinical data collected on this server computer ( 17 a ) can be uploaded to a site-managed or sponsor-managed data repository ( 25 ).
[0028] In the upper right corner of FIG. 3 , the Target Application Binary ( 15 b ) has been deployed on an additional server computer ( 17 b ) and is being used by additional client computers ( 18 c - 18 d ). This server also periodically uploads its data to a site-managed or sponsor-managed data repository ( 25 ).
[0029] In the lower left corner of FIG. 3 , a Target Application Binary ( 15 c - 15 e ), generated and compiled for a handheld destination platform such as J2ME, has been deployed on a plurality of Handheld Computers ( 16 a - 16 c ). These handheld computers are used to capture clinical data and to periodically upload it to a data repository ( 25 ) where the data can be aggregated and managed. Moreover, the data repository ( 25 ) can be the same one used by the web server computers in the upper half of the diagram.
[0030] The lower right corner of FIG. 3 illustrates a Target Application Binary ( 15 f ), generated and compiled for a server application platform like J2EE, and deployed on a web server computer ( 17 c ). In addition, a Target Application Binary ( 15 g - 15 i ), generated and compiled for a handheld destination platform such as J2ME, has been deployed on a plurality of Handheld Computers ( 16 d - 16 f ). The Handheld Computers ( 16 d - 16 f ) are used to capture clinical data and to upload that data to the Data Import and Export Module ( 24 ) of the Target Application Binary ( 15 f ) deployed on the server computer ( 17 c ). Thus, the present invention can also be executed in hierarchical configurations where one or more of a plurality of Handheld Computers ( 16 d - 16 f ) uploads data to a site-managed repository ( 17 c ), and the site-managed server ( 17 c ), in turn, uploads data to a sponsor-managed repository ( 25 ).
[0031] FIG. 4 shows an object model of the Study Protocol Description data, drawn as a Class Diagram in the Unified Modeling Language. This diagram represents in detail the structure of the data managed by the Authoring Tool ( 10 a , 10 b ). The object model is based on the Operational Data Model standard (ODM Version 1.2) developed by the Clinical Data Interchange Standards Consortium (CDISC) [reference]. Persons skilled in the art will be able to construct said Authoring Tool based on the object model in this figure.
[0032] The Study class ( 401 ) represents the complete Study Protocol Description. The Study class ( 401 ) is comprised of the following components: StudyEventDef ( 402 ) classes, FormDef ( 404 ) classes, ItemGroupDef ( 406 ) classes, ItemDef ( 408 ) classes, and CodeList ( 411 ) classes. The Association arcs from the Study class ( 401 ) to each of its component classes ( 402 , 404 , 406 , 408 , 411 ) are labeled with “0 . . . *” which denotes that the Study class ( 401 ) may be comprised of zero or more of each component class ( 402 , 404 , 406 , 408 , 411 ).
[0033] The ItemDef class ( 408 ) represents a single datum to be collected. For example, a patient's age, the current date, a patient's pulse. The ItemDef class ( 408 ) contains a number of attributes, such as the type of the datum (e.g. whether it is a number, text string, date, or time), its length, and any constraints that must be met by the datum. The RangeCheck class ( 409 ) represents simple constraints on the value of the datum; for example, “less than 5”.
[0034] Alternatively, the datum may be drawn from a list of codes. The CodeList class ( 411 ) represents a list of codes. Code lists may be used to represent different kinds of illnesses or different kinds of treatment. Each CodeList ( 411 ) is comprised of multiple CodeListItem classes ( 412 ). Each CodeListItem ( 412 ) represents one element of the code list. If the datum for a given ItemDef ( 408 ) is to be drawn from a given CodeList ( 411 ), the ItemDef ( 408 ) has a CodeListRef ( 410 ) that references the CodeList ( 411 ) for the ItemDef ( 408 ) in question. Note that the associations are defined so that each ItemDef ( 408 ) may be drawn from zero or one CodeList ( 411 ) but a CodeList ( 411 ) may be used by any number of ItemDef's ( 408 ).
[0035] Related ItemDef ( 408 ) objects are grouped by ItemGroupDef ( 406 ) objects. For example, two ItemDef ( 408 ) objects might represent the systolic and diastolic components of a patient's blood pressure. A single ItemGroupDef ( 406 ) would group them into unit that could be used and reused in multiple forms. Each ItemGroupDef ( 406 ) is comprised of one or more ItemRef ( 407 ) objects, which each reference a single ItemDef ( 408 ) object. The associations are defined such that each ItemGroupDef ( 406 ) must consist of one or more ItemRef ( 407 ) objects; each ItemDef ( 408 ) can be used by multiple ItemGroupDef ( 406 ) objects.
[0036] One or more ItemGroupDef ( 406 ) objects are grouped into a FormDef ( 404 ) class. Each FormDef ( 404 ) consists of one or more ItemGroupRef ( 405 ) objects, which each reference a single ItemGroupDef ( 406 ). For example, ItemGroupDef ( 406 ) objects representing blood pressure data and blood cholesterol data might be grouped into a single FormDef ( 404 ). The associations are defined such that each FormDef ( 404 ) must consist of one or more ItemGroupRef ( 405 ) objects; each ItemGroupDef ( 406 ) can be used by multiple ItemGroupRef ( 405 ) objects.
[0037] The StudyEventDef ( 402 ) class represents the scheduled and unscheduled events in the Study ( 401 ). For example, a complete study protocol might consist of the patient visiting a clinic 5 times over the course of several weeks. Each of these visits would be modeled as a StudyEventDef ( 402 ) object in the Study ( 401 ) description. During each visit, the study protocol specifies which forms should be completed. The FormRef class ( 403 ) models this data. Each StudyEventDef ( 402 ) is comprised of zero or more FormRef ( 403 ) objects. Each FormRef ( 403 ) references a single FormDef class ( 404 ), which defines the data collected by the form.
[0038] In the preferred embodiment of the invention, the Study Protocol Description would be representing using relational database tables corresponding to each class in object model.
[0039] The following use cases describe how the present invention might be used in the field.
USE CASE # 1A—CRF INPUTS RECORD IN THE FIELD, WEB-BASED EMBODIMENT
[0040] User ( 20 ) authenticates to the J2EE application server ( 17 ). Then User ( 20 ) keys the data into the fields of the Forms Module ( 22 ) that is displayed in the browser ( 18 ). When the data have been keyed in, the User ( 20 ) submits the populated Forms Module ( 22 ) to the Target Application Binary ( 15 ) running on the J2EE application server ( 17 ). Upon submission, the Target Application Binary ( 15 ) validates the data and creates a submission record in a structured format, such as XML, that contains the validated submission data, the submitting user's identity, and a digital signature created from the submission data, the user's identity, and a time/date stamp.
USE CASE # 1B—CRF INPUTS INVALID DATA RECORD IN THE FIELD, WEB-BASED EMBODIMENT
[0041] User ( 20 ) authenticates to the J2EE application server ( 17 ). Then User ( 20 ) keys the data into the fields of the Forms Module ( 22 ) that is displayed in the browser ( 18 ). When the data have been keyed in, the user ( 20 ) submits the populated Forms Module ( 22 ) to the Target Application Binary ( 15 ) running on the J2EE application server ( 17 ). Upon submission, the Target Application Binary ( 15 ) validates the data. If any of the data are invalid, the Target Application Binary ( 15 ) displays the populated form with appropriate diagnostic messages that allow the User ( 20 ) to correct the invalid data. When the User ( 20 ) corrects and resubmits the data to the Target Application Binary ( 15 ), an submission record in a structured format, such as XML, is created and stored as in Use Case # 1 a above.
USE CASE # 1C—CRF INPUTS RECORD IN THE FIELD, J2ME HANDHELD EMBODIMENT
[0042] User ( 20 ) invokes the Target Application Binary ( 15 ) and keys the data into the fields of the Forms Module ( 22 ) that is displayed in the Handheld Computer ( 16 ). Because of the screen size limitations of handhelds, only a subset of the input fields can be displayed at once. The Handheld Computer ( 16 ) validates the data as they are input and only allows the User ( 20 ) to display new data fields when the data for the current fields have been validated successfully. When all the data have been keyed in, the Handheld Computer ( 16 ) creates a binary submission record in its internal record store that consists of the validated submission data, the submitting user's identity, and a digital signature created from the submission data, the user's identity, and a time/date stamp.
USE CASE # 1D—CRF INPUTS INVALID DATA RECORD IN THE FIELD, J2ME HANDHELD EMBODIMENT
[0043] User ( 20 ) invokes the Target Application Binary ( 15 ) and keys the data into the fields of the Forms Module ( 22 ) that is displayed in the Handheld Computer ( 16 ). Because of the screen size limitations of handhelds, only a subset of the input fields can be displayed at once. The Handheld Computer ( 16 ) validates the data as they are input and only allows the user ( 20 ) to display new data fields when the data for the current fields have been validated successfully. If the User ( 20 ) enters invalid data, the Target Application Binary ( 15 ) will immediately mark the data as invalid and require the User ( 20 ) to correct the data before moving on to the next field. Once the User ( 20 ) has entered validated data for all fields in the form, the Handheld Computer ( 16 ) will create and store a binary submission record in its internal record store as in Use Case # 1 c above.
USE CASE # 2—DATA ARE CONSOLIDATED ON BACK END
[0044] In FIG. 3 , one or more of a plurality of Handheld Computers ( 16 a - 16 c ) are used to collect data from a number of trial subjects. The data collected must be aggregated to one or more Data Repositories ( 25 a - 25 c ) managed by an investigative site (e.g. a research hospital or clinic) or by the sponsor of the clinical trial to enable subsequent analysis. The User ( 20 ) of the Handheld Computer ( 16 ) initiates a network connection to Data Repository ( 25 ) and authenticates. The network connection can be made using any technology such as serial data connection, wired local-area network connection, or wireless network connection. Once the User ( 20 ) has connected and authenticated to the Data Repository ( 25 ), the Data Import and Export Utility ( 24 ) running on the Handheld Computer ( 16 ) transforms the binary submission records into digitally signed documents in a structured format, such as XML, and transmits them over the network connection. The means for merging the submission documents into the Data Repository ( 25 ) is any clinical data management system that has facilities for importing documents in a structured format, such as XML. When the Data Repository ( 25 ) receives a document in a structured format, such as XML, it verifies the document's digital signature. If the Data Repository ( 25 ) successfully verifies the signature, it adds the document to its permanent storage. If the Data Repository ( 25 ) does not verify the digital signature, it returns an error code to the Handheld Computer ( 16 ) and takes no further action.
[0045] As shown in FIG. 3 , the present invention allows server-to-server data consolidation as well. Server to server consolidation would be commonly used where clinical data are collected at an investigative site and uploaded to a central trial management server. In this scenario, a site-wide system ( 17 a , 17 b , or 17 c in FIG. 3 ) connects to a trial-wide data repository ( 25 ) and the site data located is then consolidated for the trial. In an environment with multiple Data Repositories ( 25 a - 25 c ), each individual repository may be managed by different entities, and thus is likely communicating over wide-area network links. Each of the plurality of Data Repositories ( 25 a - 25 c ) should communicate using secure connections; in the preferred embodiment, Secure HTTP with bi-directional certificate-based authentication [c.f. RFC 2246]. Once the secure channel is established between the site-wide ( 17 a - 17 c ) and the trial-wide Data Repository ( 25 ), the site-wide servers asynchronously upload their submission documents in a structured format, such as XML, to the trial-wide Data Repository ( 25 a - 25 c ). Upon receiving the submission documents, the trial-wide Data Repository ( 25 a - 25 c ) attempts to verify the digital signatures of the documents. If the Data Repository ( 25 ) successfully verifies the signature, it adds the submission document to its permanent storage. If the Data Repository ( 25 ) does not verify the digital signature, it returns an error code to the site-wide server ( 17 ) and takes no further action.
USE CASE # 3—AUTHORING OF FORMS FOR CLINICAL STUDIES
[0046] To create forms for a clinical study, the user uses an Authoring Tool ( 10 a , 10 b ) running on a handheld computer, laptop computer, or a desktop workstation. Authoring forms for a clinical study consists of defining the scheduled and unscheduled events in the study and the forms that will be collected during each of these events. In turn, a form definition consists of the fields, the validation rules for each field, the definition of code lists for those fields that require them, how each field in the form will be grouped into related fields that are presented together.
[0047] When the study definition is complete, it is converted into a Study Protocol Description ( 19 ) and saved to the Persistent Design Repository ( 11 ). The authoring tool ( 10 a , 10 b ) saves the Study Protocol Description ( 19 ) to the design repository by opening a network connection to the Persistent Design Repository and authenticating. Then the authoring tool ( 10 a , 10 b ) uploads the Study Protocol Definition ( 19 ) to the Persistent Design Repository ( 11 ) where it is stored.
USE CASE # 4—UPDATING EXISTING FORMS FOR CLINICAL STUDIES
[0048] If the Study Protocol Description ( 19 ) is updated after the Target Application Binary ( 15 ) has been generated and deployed to the destination platform, a new Target Application Binary ( 15 ) reflecting the updated study protocol definition must be re-generated and re-deployed. When the Study Protocol Description ( 19 ) is updated in the authoring tool ( 10 a , 10 b , FIG. 1 ), the authoring tool keeps track of the changes and how they differ from the original definition. When all the changes have been made, the authoring tool creates a difference list, or list of changes made to the original study definition; the updated study definition can be obtained by starting with the original study definition and applying the modifications in the difference list. The new Study Protocol Description ( 19 ) and the difference list are saved to the Persistent Design Repository ( 11 ).
[0049] Once the updated Study Protocol Description ( 19 ) study definition has been saved to the Design Repository ( 11 ), Because the Design Repository ( 11 ) still has the complete definition for both the original and the updated studies, the Generator ( 12 ) may optionally generate support for both the original as well as the updated study in the new Target Application Source Code ( 13 ). The work essentially consists of generating two sets of Target Application Source Code ( 13 ), one for each version of the Study Protocol Description ( 19 ), target applications for both studies and packaging them into a single application deployment unit for the destination platform.
[0050] When the Target Application Binary ( 15 ) is updated, the present invention relies on a system administrator to facilitate the deployment of the updated information to the destination platform. Destination platforms frequently have a unique mechanism for deploying applications; in the case of J2ME-capable devices, each hardware manufacturer has a proprietary method for deploying J2ME applications, either using desktop synchronization software or some variety of over-the-air deployment for wireless devices.
[0051] While certain exemplary embodiments have been described in detail and shown in the accompanying drawings, it is to be understood that such embodiments merely illustrate rather than restrict the broad invention, and that this invention is not to be limited to the specific arrangements and constructions shown and described, since various other modifications may occur to those with ordinary skill in the art.
|
Apparatus and method is disclosed for a data collection and monitoring system that utilizes a remote collection unit which has contained therein interaction software that allows the user to define and import data collection scenarios, capture data, update data, query data, and notify the user of adverse conditions triggered by the entered data values. The system has a means to allow transfer of the collected data to a main computer database for further review, reporting, and distribution purposes.
| 6
|
BACKGROUND OF THE INVENTION
This is a Continuation-In-Part of application Ser. No. 07/621,412, filed Dec. 3, 1990 now U.S. Pat. No. 5,089,631; which is a Division of application Ser. No. 07/492,196, filed Mar. 13, 1990, now U.S. Pat. No. 5,003,086; which is a Division of application Ser. No. 07/352,070, filed May 15, 1989, now U.S. Pat. No. 4,943,642.
This invention relates to novel halo-oxydiphthalic and dioxydiphthalic bis-imide compounds. The products are useful chemical intermediates for the further preparation of various compounds and polymers, especially as monomers in the preparation of polyimides.
Kolesnikov, G.S. et al, Vysokomol. Soyed, A9, 612-18 (1967); Marvel, C.S. et al, J. Am. Chem. Soc., 80, 1197, (1958); and Latrova, Z.N. et al, Volokna Sin. Polim., 15-24 (1970), disclose the preparation of oxydiphthalic acids and anhydrides by the oxidation of tetramethyldiphenyl ethers.
U.S. Pat. No. 4,697,023 discloses the preparation of oxydiphthalic anhydrides and suggests their use in the preparation of polyimides. The oxydiphthalic anhydrides are prepared by the reaction of a halophthalic anhydride with water and an alkali metal compound such as KF, CsF, or K 2 CO 3 in the presence of a polar aprotic solvent.
U.S. Pat. No. 3,879,428 to Heath et al discloses the preparation of various aromatic bis(ether anhydrides) by reaction of nitrophthalimide with an alkali diphenoxide followed by hydrolysis to yield the diether anhydride.
German Patent No. 2,416,594 (1975) discloses the preparation of oxydiphthalic anhydride by coupling of 3-nitrophthalic anhydride in the presence of metal nitrites such as sodium nitride.
Tilika et al, Synthesis of Carboxylic Acids of Aromatic Sulfides, Latv. PSR Zinat. Akad. Vestis, Kim. Ser. (2), 201-4, 1982; CA 97(7):55412U, disclose the reaction of 5-bromo-4-mercaptophthalic acid with Cu 2 O to give 80 percent thianthrene-2,3,7,8-tetracarboxylic acid, that is, ##STR3##
Pebalk et al, Spin Density Distribution In Anion Radicals of Aromatic Tetracarboxylic Acid Dianhydrides, Dokl. Akad. Nauk, SSR, 244(5), 1169-73, [Phys. Chem.] 1979; CA 90(23):186029c, disclose the EPR spectra of various compounds including a compound of the structure ##STR4##
Pebalk et al, Electron-acceptor Properties of Aromatic Dianhydrides, Dokl. Akad. Nauk, SSR, 236(6), 1379-82, [Chem.] 1977; CA 88(19):135960a, disclose the electron-acceptor properties of 15 phthalic anhydrides and condensed phthalic anhydrides including dithio-diphthalic anhydrides.
2,3,7,8-Tetracarboxyphenoxathin dianhydride of the formula ##STR5## is disclosed by Erglis et al., (USSR Patent No. 395,358; CA 80(9):48007m). The compound was prepared by the reaction of (3,4-Me 2 C 6 H 3 ) 2 O with sulfur in the presence of aluminum chloride followed by oxidation with KMnO 4 in aqueous piperidine to form the tetracarboxylic acid, which was cyclized.
SUMMARY OF THE INVENTION
The present invention relates to new aromatic bis-imides of the formula ##STR6## where Z is H, alkyl of 1-12 carbon atoms, or ##STR7## Y is H, Cl, F, NO 2 , OH, or CF 3 ; A is H, Cl, F, NO 2 , OH, CF 3 , alkyl, alkoxy, alkylaryl or aryloxy, wherein the alkyl groups are 1-6 carbon atoms and the aryl groups are 6-14 carbon atoms; alkenyl or alkynyl of 2-6 carbon atoms; or benzoyl; X is F, Cl, Br or I, X' is H, F, Cl, Br or I, or X and X' may together represent an oxygen atom forming a second ether linkage, with the proviso that when X and X' are taken together to represent an oxygen atom, the ether linkage is positioned at ring carbon sites adjacent to the sites forming the first ether linkage shown.
DETAILED DESCRIPTION OF THE INVENTION
The novel bis-imides of the above formula (I) may be prepared by reaction of the corresponding dianhydride with ammonia (to prepare the compound of Formula I wherein Z is hydrogen) or with an alkylamine or a suitably substituted aniline compound.
The halo-oxydiphthalic or dioxydiphthalic anhydride reactants used for the preparation of the bis-imides of Formula I can be prepared by reacting a dihalophthalic anhydride of the formula ##STR8## where Hal is F, Cl, Br or I with water and an alkali metal compound selected from the group consisting of KF, CsF, and K 2 CO 3 .
In the process, the halogen atoms on the dihalophthalic anhydride reactant function as leaving groups and become the site for the formation of an ether bridge. Thus, when the reactant is a 4,5-dihalophthalic anhydride such as ##STR9## the reaction products will include 4,4'-dihalo-5,5'-oxydiphthalic anhydride, characterized by the formula ##STR10## and 4,4',5,5'-dioxydiphthalic anhydride characterized by the formula ##STR11## The particular halogen atoms at the 4 and 4' positions will depend on the halogen atoms present at the 4 or 5 position of the starting dihalophthalic anhydride. Thus, for example, the above dichloro-oxydiphthalic anhydride (IV) may be formed from 4,5-dichlorophthalic anhydride starting material. When difluorophthalic anhydride is employed, the corresponding difluoro-oxy-diphthalic anhydride may be formed. In addition, a mono-chloro-oxydiphthalic anhydride may be formed by using as a starting reactant a mixture of a monohalophthalic anhydride, such as 4-chlorophthalic anhydride and a dihalophthalic anhydride, such as 4,5-dichlorophthalic anhydride. Furthermore, the ring site of the oxygen bridge(s) may be varied by selective choice of the halophthalic anhydride reactant employed.
While not being bound by any particular theory, it is believed that the oxy-dihalo-diphthalic anhydride is formed as an intermediate during the initial stages of reaction. The percentage yield thereof may be enhanced by limiting the time of reaction. Alternatively, by increasing the reaction time, the dioxydiphthalic anhydride is produced essentially as the sole product. The halo-substituted oxydiphthalic anhydride is separable from the dioxydiphthalic anhydride by common physical separation means, such as selective recrystallization, etc. Fluoro-substituted bis-imides, prepared for example from difluoro-oxydiphthalic anhydride may be employed in the preparation of polyether imides having improved electrical properties, such as dielectric strength. In addition, the presence of fluorine ring substituents should increase the solubility of the polyimide in common solvents.
When the reactant is 3,4-dihalophthalic anhydride, the oxydiphthalic anhydride product formed will be 3,3',4,4'-dioxydiphthalic anhydride which, upon reaction with ammonia or an amine, will form a bis-imide characterized by the formula ##STR12## where Z is as defined above.
Alternatively, a mixture of the 3,4-dihalo- and 4,5-dihalo-phthalio anhydrides may be employed as the starting reactant to form a dioxydiphthalic anhydride which, upon reaction with ammonia or an amine, will form a bis-imide of the formula ##STR13## where Z is as defined above.
The halogen substituents on the starting halophthalic anhydride reactant may be F, Cl, Br or I. The preferred reactant is 4,5-dichlorophthalic anhydride.
The alkali metal compound may be potassium fluoride, cesium fluoride, or potassium carbonate, the latter being preferred. The proportions of reactants may vary considerably. However, it is recommended that the alkali metal compound be employed in sufficient proportions to provide at least two equivalents of potassium (or cesium) per mole of dihalophthalic anhydride. Preferably, the alkali metal compound is employed in substantial stoichiometric excess.
In the preparation of the halo-oxydiphthalic or dioxydiphthalic anhydride, water is a limiting reactant. Ideally, for maximum efficiency in the preparation of dioxydiphthalic anhydride, water is preferably present in a molar proportion of H 2 O:dihalophthalic anhydride of about 1.0. The amount of halo-substituted oxydiphthalic anhydride produced can be increased by limiting the ratio of water to dihalophthalic anhydride to less than 1:1. The water may be added to the initial reaction mixture or alternatively, may be generated in situ. For example, when potassium carbonate is employed in the reaction mixture, a trace amount of water may be present in the initial reaction mixture and additional water generated in situ as the reaction proceeds.
The process is preferably carried out at atmospheric pressure, but super-atmospheric pressure, for example under autogenous conditions may be employed, if desired.
The process is preferably carried out neat. However, a solvent may be employed. The preferred solvents are polar, aprotic solvents such as N-methyl pyrrolidone, dimethyl formamide, dimethyl acetamide, triglyme, sulfolane, or the like, the most preferred solvent being sulfolane.
The temperature at which the process for the preparation of the dianhydride is carried out may vary considerably, but will generally be within the range of about 120° to about 230° C. Higher or lower temperatures may be employed, but are less preferred. If a solvent is employed, the choice of the solvent may govern the temperature employed. For example, at atmospheric conditions the boiling point of the solvent may become a limiting condition.
The dianhydride may be reacted with ammonia to form the corresponding ammonium phthalamate, heated to form diphthalamic acid, and dehydrated to yield the corresponding bis-imide. In a preferred embodiment, the dianhydride is reacted with an excess of concentrated ammonium hydroxide at reflux conditions to prepare the bis-ammonium phthalamate. The reaction mixture is then heated to remove water and excess ammonia. The phthalamic acid is then heated, preferably to at least 200° C., to form the bis-imide.
In the preparation of the substituted bis-imides of this invention, the diphthalic anhydride is reacted with an appropriately substituted amine, preferably in a molar ratio of amine:diphthalic anhydride of at least 2:1. The reaction may be carried out neat, but is preferably carried out in a solvent. The preferred solvents are polar, aprotic solvents such as N-methyl pyrrolidone, dimethyl formamide (DMF), dimethyl acetamide (DMAc), triglyme, sulfolane, or the like, the most preferred solvent being DMAc. The reaction is preferably carried out at a temperature of about 110° to 200° C., advantageously at reflux conditions. The reaction is typically carried out at atmospheric pressure. However, super-atmospheric or sub-atmospheric conditions may be employed, but are not generally preferred.
The bis-imides of the present invention are useful as monomers and/or additives in the formulation or preparation of various polymers. For example, the present bis-imides may be employed in the preparation of polyetherimides through an imide-amine exchange reaction catalyzed by a basic catalyst, such as an alkali metal or alkaline earth metal, or basic compounds thereof such as hydroxides, oxides, hydrides, carbonates and the like. In the process, a mixture of equal molar amounts of the dioxy diphthalic bis-imide of Formula 1 and an organic diamine are heated to the molten state, in the presence of the basic catalyst, to effect the imide-amine reaction. The process may be carried out under reduced pressure to facilitate the removal of the mono-organic amine and the formation of the polyetherimide. Suitable organic diamines include, for example, those of the formula NH 2 -R-NH 2 where R is a divalent organic radical such as an alkylene or aromatic radical. Additional details regarding suitable diamines as well as suitable catalysts and general process conditions are set forth in U.S. Pat. No. 3,847,870.
In an alternate process, bis-imides compounds of the present invention such as compounds of Formula I, wherein Z is ##STR14## may be reacted with a dihydroxy compound, such as a diphenol or a bis-phenol compound to form a polyetherimide. For example, the bis-imide of Formula I where Z is ##STR15## may be reacted with equal molar amounts of p-hydroxybenzophenone to form a poly(imide-ether-ketone).
In addition, the present bis-imides may be employed as plasticizers for organic polymers, such as polyvinylchloride and polyimides.
The following examples are provided to further illustrate the invention in the manner in which it may be carried out. It will be understood, however, that the specific details given in the examples have been chosen for purposes of illustration only and are not to be construed as limiting the invention. In the examples, unless otherwise indicated, all temperatures are in degrees Celsius.
EXAMPLE 1
Preparation of Dioxydiphthalic Anhydride
A solution of 21.7 grams (0.1 mole) of 4,5-dichlorophthalic anhydride in 40 grams of sulfolane was heated and maintained at 210°-215° C. while 0.215 grams of tetraphenylphosphonium bromide was added followed by the incremental addition of 13.82 grams (0.1 mole) of potassium carbonate over a period of about 4 hours. The temperature was maintained an additional hour and the reaction mixture was then cooled to room temperature. Acetone (100 ml) was added and mixed. The reaction mixture was filtered and the solids washed consecutively with another 100 ml of acetone, two 100 ml portions of water, and again with 100 ml of acetone, to yield about 15 grams of brown solid. After drying, the solid was recrystallized from about 225 grams of 1,2,4-trichlorobenzene to yield 12.5 grams of a tan colored crystalline solid. Mass spectral analysis indicated the product to have a molecular weight of 324 with a fragmentation consistent with dioxydiphthalic anhydride. The identification of dioxydiphthalic anhydride was confirmed by infra-red analysis and C 13 NMR (CP/MAS).
EXAMPLE 2
Preparation of Dioxydiphthalic Anhydride
4,5-Difluorophthalic anhydride (18.4 grams, 0.1 mole) was dissolved in 40 grams of anhydrous sulfolane and heated to 165° c. with stirring. Tetraphenylphosphonium bromide (0.184 grams, 0.0004 mole) and 1.8 grams (0.10 mole) of water were added and the temperature increased to 200° C. Anhydrous potassium fluoride (23.3 grams, 0.4 mole) was added with stirring. The reaction mixture was held at about 200° C. with stirring for about 3 1/2 hours at which time another 0.2 grams of water was added and the reaction mixture was maintained at temperature for an additional hour. The reaction mixture was cooled to less than 150° C. and 35 grams of acetone added and the solids filtered off. The solids were washed with acetone followed by three 100 ml washes with distilled water. The solid material was dried at 150° C. for 16 hours to yield 15.5 grams (95.7% yield) of dioxydiphthalic anhydride.
EXAMPLE 3
Preparation of Dioxydiphthalic Acid
Dioxydiphthalic anhydride (3.0 g, 0.009 mole) was added to 95 g of water and heated to reflux. The dianhydride was dissolved by the addition of 4 ml of 40% NaOH. The resulting brown solution was decolorized with 0.2 g of activated carbon at reflux for 0.5 hour followed by filtration through celite. Acidifying with 12N HCl to a pH of less than 1 followed by a water wash and drying gave 1.9 g of product as confirmed by FTIR. DSC melting point was 260° C. with loss of water.
EXAMPLE 4
This example illustrates the manner in which chloro-oxydiphthalic anhydride may be prepared.
A solution of equal molar amounts of 4-chlorophthalic anhydride (18.2 g, 0.1 mole) and 4,5-dichlorophthalic anhydride (21.7 g, 0.1 mole) in 60 g of sulfolane is heated to 180°-210° C. Temperature is maintained, with stirring, while 0.05 mole (6.91 g) of potassium carbonate is added over a period of about one hour. The temperature is maintained for an additional two hours, then lowered to room temperature.
EXAMPLE 5
Potassium fluoride (5.04g) and Carbowax MPEG 2000 (0.71 g) were added to and mixed with 10.2 g of a mixture of 56.1% (GC are percent) 4,5-difluorophthalic anhydride and 43.9% (GC area percent) 4-chloro-5-fluorophthalic anhydride. The powdery mixture was heated in a flask to 180° C., forming a viscous, paste-like reaction mixture. The temperature was maintained at 180°-207° C. for approximately 3.5 hours, during which a portion of the reaction mixture sublimed and condensed on the upper portion of the flask. The flask was cooled to room temperature and the sublimate collected (6.69 g) and analyzed by gas chromatography, indicating, in area percent, 74% 4,5-difluorophthalic anhydride and 26% 4-chloro-5-fluorophthalic anhydride. The reaction mixture remaining at the bottom of the flask (7.58 g) was analyzed by gas chromatography and found to contain in area percent, 50.1% 4,5-difluorophthalic anhydride; 42.8% 4-chloro-5-fluorophthalic anhydride; 3.4% 4,4'-difluoro-5,5'-oxydiphthalic anhydride; 2.1% 4-chloro-4'-fluoro-5,5'-oxydiphthalic anhydride; 0.3% 4,4'-dichloro-5,5'-oxydiphthalic anhydride and 1.0% 4,4',5,5'-dioxydiphthalic anhydride.
EXAMPLE 6
Preparation of Bis-imide of Dioxydiphthalic Anhydride ##STR16##
Dioxydiphthalic anhydride (6.52 g, 0.0020 mole) was added to 200 ml of concentrated ammonium hydroxide in a round bottom flask fitted with a reflux condenser. The mixture was heated to reflux over a period of about one-half hour during which the mixture turned dark brown in color. The reflux condenser was removed from the reaction flask and, with continued heating, most of the remaining liquid was removed, to leave an olive-green solid. The solid was dried and mixed with N,N-dimethylacetamide (DMAc) and the mixture heated to reflux to form an amber solution. The solution was treated with decolorizing carbon, filtered, and cooled to form white crystals. The crystals were washed with acetone and dried to yield a final product (5.25 g, 81% yield) in the form of pale yellcw crystals (M.P. =>400° C.)
EXAMPLE 7
Preparation of Bis(N-p-hydroxyphenyl)imide of dioxydiphthalic Anhydride ##STR17##
To 1.20 g (0.11 mole) of 4-aminophenol in 50 mL of DMAc was added 1.62 g (0.003 mole) of dioxydiphthalic anhydride. The mixture was refluxed under an atmosphere of nitrogen for 3.5 hours. The resulting slurry was filtered, washed with acetone, and dried, to yield 2.13 g (90% yield) of white crystals which, upon heating, exhibited charring at about 400° C.
EXAMPLE 8
Preparation of Bis(N-p-chlorophenyl)imide of Dioxydiphthalic Anhydride ##STR18##
To 1.40 g (0.009 mole) of 4-chloroaniline in 50 mL of DMAc was added 1.62 g (0.003 mol) of dioxydiphthalic anhydride. The mixture was refluxed for 19 hours under an atmosphere of nitrogen, and the resulting slurry was filtered, rinsed with acetone, and dried to yield 2.1 g (84% yield) of bis-N-p-chlorphenyl)imide of dioxydiphthalic anhydride as yellow crystals (M.P. >400° C.)
EXAMPLE 9
Preparation of Bis(N-p-fluorophenyl)imide of Dioxydiphthalic Anhydride ##STR19##
The bis-N-p-fluorophenyl)imide of dioxydiphthalic anhydride is prepared following the general procedure of Example 8, except that in place of 4-chloroaniline, there is substituted a molar equivalent amount of 4-fluoroaniline.
EXAMPLE 10
Preparation of the Bis(N-p-nitrophenyl)imide of Dioxydiphthalic Anhydride ##STR20##
To 1.52 g (0.011 mole) of 4-nitroaniline in 50 mL of DMAc, was added 1.62 g (0.003 mole) of dioxydiphthalic anhydride. The mixture was refluxed under a nitrogen atmosphere for two hours. The resulting slurry was filtered and rinsed with acetone to yield 1.4 g of yellow solid (51% yield). Upon heating, charring occurred at about 400° C.
The bis(N-p-nitrophenyl)imide of dioxydiphthalic anhydride, prepared in accordance with Example 10, may be reduced to the diamine by reduction with hydrogen over Pd/C in DMAc.
EXAMPLE 11
Preparation of Bis(N-p-aminophenyl)imide
The bis(N-nitrophenyl)imide prepared in accordance with Example 10 is dissolved in a solvent, such as DMAc, and reduced with hydrogen over Pd/C to form the corresponding diamine.
EXAMPLE 12
Preparation of the Bis(N-p-trifluoromethylphenyl)imide of Dioxydiphthalic Anhydride ##STR21##
The bis(N-p-trifluoromethylphenyl)imide of dioxydiphthalic anhydride is prepared following the general procedure of Example 10, except that, in place of 4-nitroaniline, there is substituted an equivalent molar amount of 4-trifluoromethylaniline.
EXAMPLE 13
Preparation of the N-phenyl Bis-imide of Dioxydiphthalic Anhydride ##STR22##
To 1.03 g (0.01 mole) of aniline in 50 mL of DMAc was added 1.62 g (0.003 mole) of dioxydiphthalic anhydride. The mixture was refluxed, under nitrogen, for two hours. The resulting slurry was filtered and washed with acetone and dried.
|
Bis-imides of dioxydiphthalic or oxydiphthalic anhydride, are characterized by the formula ##STR1## where Z is H, alkyl of 1-12 carbon atoms, or ##STR2## A is H, Cl, F, NO 2 , OH, CF 3 , alkyl, alkoxy, alkylaryl or aryloxy, wherein the alkyl groups are 1-6 carbon atoms and the aryl groups are 6-14 carbon atoms; alkenyl or alkynyl of 2-6 carbon atoms; or benzoyl; and Y is H, Cl, F, NO 2 , OH, or CF 3 ; X is halogen; X' is hydrogen or halogen; or X and X' together represent an oxygen atom, forming a second ether linkage.
| 2
|
This application is a continuation in part of Ser. No. 12/798,826 filed Jun. 11, 2010 now abandoned.
BACKGROUND OF THE INVENTION
For the better part of the 20 th century, athletic shoes have been in use all over the world. Most households have at least one pair. They require little maintenance, and only require washing and drying every so often. Laundering athletic shoes requires nothing special they can be air-dried or put in the dryer.
However, when using a dryer, shoes tumble and bounce loudly, creating a noisy nuisance and potentially causing damage to the dryer and shoe. For this reason, most people prefer to air-dry their athletic shoes, which can take a long time.
I believe there is a need for a device that allows the drying of athletic shoes in a laundry dryer without creating excess noise or risking damage.
BRIEF SUMMARY OF THE INVENTION
The invention includes a magnetic apparatus having a center portion with flat upper and bottom surfaces and rectangular casings at the opposite ends. The magnetic apparatus aligns with the longitudinal axis of an athletic shoe, a band and a rectangular rod for keeping the mouth area of an athletic shoe open during the drying process. The apparatus has opposite ends, along the longitudinal axis, that bend upwards towards the sole of the athletic shoe on each end of the magnet apparatus with the rectangular casings having with permanent magnets attached thereto so that the apparatus may be attached to a laundry dryer drum. In use, the magnetic apparatus is to be placed on the sole of a tennis shoe or athletic shoe in the longitudinal direction and attached thereto by use of a stretchable band that encircles both the center mouth area of the tennis shoe and the magnetic apparatus. The magnetic apparatus is to be magnetically attached to the curvature of a dryer drum. A rectangular rod is placed in the upper lacing area of the shoe lengthwise to keep the upper mouth area of the shoe open for superior drying results. When drying is complete, simply remove shoe and apparatus from dryer drum with caution.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of partly magnetic apparatus 2 is a view of a shoe stuck to dryer drum with band 80 .
Position A in FIG. 1 shows stretchable band 80 around bottom 13 of apparatus 2 and shoe. Position B in FIG. 1 shows rectangular rod 14 in upper mouth area of the shoe, with the band around the center mouth area of shoe and the magnetic apparatus. Position C in FIG. 1 shows magnetic apparatus 2 and the shoe stuck to dryer drum with band 80 .
FIG. 2 and FIG. 2A is a side and bottom 9 and back and front view of magnetic apparatus 2 with each opposite bottom end bent upwards.
FIG. 3 and FIG. 3A is an upper view of apparatus 2 bent upward on each opposite end and also a back and front and side view.
FIG. 4 and FIG. 4A is a view of the rectangular rod.
FIG. 5 and FIG. 5A is a view of stretchable band 80 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a conventional laundry dryer 55 with the plurality of magnetic apparatus 2 individually attached to athletic shoes 3 . Magnetic apparatus 2 having a center portion with flat upper surface 13 and flat bottom surface 9 , rectangular casings 7 , as clearly shown in FIGS. 1 , 2 and 3 , that align with the longitudinal axis of an athletic shoe 3 , a band 80 ( FIG. 1 , Positions A and C and FIG. 5 ) and a rectangular rod 14 ( FIG. 1 , Position B and FIG. 4 ) for keeping the mouth area of an athletic shoe 3 open during the drying process, see FIG. 1 , Position B. The magnetic apparatus 2 has casings 7 , along the longitudinal axis, that bend upwards towards the athletic shoe 3 when the magnetic apparatus 2 is attached to an athletic shoe 3 . Each end of the magnetic apparatus having a permanent magnet 1 attached on the respective opposite ends of the respective casings. The magnets 1 are used to attach the apparatus 2 and corresponding athletic shoe 3 to a conventional laundry dryer 55 .
In use, the apparatus 2 is placed on the bottom center of a tennis shoe or athletic shoe 3 along the longitudinal axis by use of a stretchable band 80 that encircles the center mouth area of a tennis shoe 3 and the magnetic apparatus 2 . The magnetic apparatus 2 is to be magnetically attached, via magnets 1 , to the curvature of a dryer drum 55 , see FIG. 1 , Position C. A rectangular rod 14 is placed in the upper lacing area of the shoe lengthwise to keep the upper mouth area of the shoe 3 open for superior drying results. The conventional dryer is operated in the conventional manner with the apparatus 2 and shoe 3 attached as described above until the shoe is dried. When drying is complete, simply remove shoe and apparatus from dryer drum with caution.
The magnetic apparatus 2 while being illustrated as rectangular may be embodied in additional shapes. Apparatus 2 and casing 7 can be attached by rivets 19 . Apparatus 2 and casing 7 can be made of all solid material and may be slightly flexible or not and made from such materials such as wood, fiberglass, plastic, and rubber. Casing 7 can be integrated into apparatus 2 as a single piece. Apparatus 2 will have a length of 9 to 14 inches between magnets 1 and casing 7 areas. The area between the casing 7 and magnet 1 will have a thickness of 0.25 mm to 1½ mm. Where casing 7 and magnet 1 are located and apparatus 2 combined will have a thickness of ½ to 1 inch. Apparatus 2 will have a width of ½ to 1 inch. Rivets 19 can also be made of all solid non-flexible materials. Rod 14 can be made of all solid materials that are non-flexible. Rod can be spiked or not. Rod 14 will have a length of 1 to 6 inches, a thickness of ½ mm to 1 mm, a width of ½ to 1 mm. Stretchable band 80 will have a length of 1 to 6 inches, a thickness of ½ mm to 1 mm, and a width of ½ to 1 inch. Band 80 can be made of all stretchable or non-stretchable fabrics. Rectangular magnets 1 will be wedged down into rectangular casings 7 with powerful heat-resistant super glue. Magnet 1 can be made of all powerful magnetic materials such as ceramic and metallic magnets 1 . Magnetic apparatus 2 and casing 7 can be made of metal. Rod 14 can be partly rectangular or other shapes and spiked on each opposite end or not. When in an operative position adjacent to an athletic shoe, apparatus 2 will have ends that are slightly bent upwards on each opposite end 10 towards the sole of the athletic shoe. Apparatus 2 will be rectangular and can also be formed in other shapes. Apparatus 2 will, have a flat upper surface 13 and a flat bottom surface 9 . Rivets 19 can also be slightly, flexible or not flexible.
|
I have invented a partially magnetic apparatus ( 2 ) that will consist of stretchable band ( 80 ) and a rectangular rod ( 14 ) is to be inserted into the upper lacing area of the athletic shoe ( 3 ) width wise magnetically attaching athletic shoe ( 3 ) to dryer's drum ( 55 ) while dryer is in motion.
| 3
|
BACKGROUND OF THE INVENTION
The present invention relates generally to guide assemblies and, more particularly, to a guide assembly having multiple passage guides connected thereto.
During construction of residential and commercial facilities, it is often required to pass conductors through the structure of the facility. Such conductors include power cables, water lines, phone cables, and television signal cables. Additionally, with the proliferation of “smart buildings” it has become more desirable and cost efficient to pass computer cables as well as entertainment and security cables within wall, floor, and ceiling cavities. Such systems are often referred to as structured wiring systems and often include a bundled array of phone, computer, co-axial, and speaker cables.
Often, the devices associated with a specific system share a common point of origin. For simplicity, only one such system will be described. In buildings equipped with radiant heat systems, a plurality of radiant heating loops are connected to a manifold and extend about the building. The simplest of radiant heating loops have a first end connected to a hot water inlet, extend about the area to be heated, and have a second end connected to a return manifold thereby forming a “loop”. A heating fluid, such as water, is heated by a heat source, such as a water heater or boiler, and is pumped through the heating loop. Such radiant heating loops are frequently located in close proximity to a finish floor of the area to be heated. The heating loops can be positioned beneath a subfloor or sandwiched between a subfloor or substrate, and a finish floor.
To maximize the usable space of a structure, the heating loops often extend generally transverse to the floor surfaces in close proximity to a wall surface. Such an orientation minimizes the space obstructed by the heating tubes. Often, an elbow is employed to facilitate this generally transverse directional change. For radiant heat systems, each end of a loop must be threaded through an elbow. A single loop heating system requires an elbow to be passed over each end of the heating tube. Each elbow must then be securely fastened to a sub-surface to allow a finish floor to be formed thereabout. Individually securing each elbow is a time consuming and tedious process and often delays the construction process. Although there are known elbow constructions that allow the conduit to pass radially into the elbow, these elbows only support individual conductors. That is, often multiple elbows must be individually secured and individual conductors passed therethrough or thereinto. Additionally, depending on the finish floor system formed about the heating tubes, inadvertent movement of the individual elbows can result in damage or displacement of the conductor passed therethrough during formation of the finish floor.
Radiant floor heating has gained increased acceptance as the preferred heating method for spaces built on grade or in basements. The radiant tubes are often attached to a supporting structure and a concrete floor is often poured thereover. The process of finishing a concrete floor often employs the application of a power trowel. The power trowel includes a plurality of individual floats attached to an engine. Operation of the engine rotates the floats and as the power trowel is moved across the surface of the floor, the floats provide a relatively smooth and flat finish of the floor. An operator of the power trowel must be particular careful during finishing of the floor near the array of individual elbows that have been passed thereinto. Although the concrete is generally stiff enough to support the weight of the power trowel and an operator thereof, inadvertent contact between the power trowel and the elbows can result in displacement of the elbows from their secured location. Such an event produces a relatively unsightly finished alignment of the individual elbows and/or a blemish in the finish of the floor. Worse yet, if the floats of the power trowel contact the radiant tube or other conductor passed through the elbow, the float could sever the conductor or minimally form a leak in fluid communicating conductors.
It would therefore be desirable to have a system and method capable of quickly and efficiently guiding and securing a plurality of conductors in such applications.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides a system and method that solves the aforementioned drawbacks. Specifically, a system for arranging a plurality of conductors includes a guide body having a plurality of passage guides connected thereto. Each of the plurality of passage guides is constructed to direct the passage of an individual conductor therethrough. The guide body is securable to a substrate and constructed to organize the individual conductors connected thereto. The individual conductors communicate any one of a fluid, an electrical power, a hydraulic fluid, or the like through the guide body.
Therefore, in accordance with one aspect of the present invention, a guide assembly is disclosed that has a body having a first surface and a second surface, wherein the first surface is arranged in a first direction and the second surface is arranged in a second direction that extends outwardly from the first direction. The guide assembly also includes a number of passage guides extending through the body, each passage guide having an inlet generally aligned with the first surface of the body and an outlet generally aligned with the second surface. The passage guides are constructed to allow the passage of a plurality of conduits or conductors therethrough between the first surface to the second surface.
According to another aspect of the present invention, a guide system includes a first body, a second body connected to the first body, and a plurality of tubes. The tubes are connected to at least one of the first and second bodies and each tube has a first end facing a first common direction and a second end facing a second common direction, wherein the two directions are other than parallel.
In accordance with a further aspect of the present invention, a guide system includes a method of securing a conduit array that includes the step of securing a guide block to a substrate and securing a first conduit to the block such that the first conduit extends in crossing directions from the guide block. The process also includes securing a second conduit to the guide block such that the second conduit extends in directions generally similar to the first conduit.
According to a further aspect of the present invention, a guide assembly is set forth having a body with first and second portions, wherein the second portion extends from the first portion. A first set of retainers is attached to the first portion of the body in and a second set of retainers is attached to the second portion of the body and is generally aligned with the first set of retainers. The retainers are constructed to retain a plurality of conduits therein.
Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.
In the drawings:
FIG. 1 is a perspective view of one embodiment of a guide assembly according to the present invention secured in a substrate.
FIG. 2 is a perspective view of the guide assembly shown in FIG. 1 .
FIG. 3 is a cross-sectional view of the guide assembly along line 3 - 3 of FIG. 2 .
FIG. 4 is a perspective view of another embodiment of a guide assembly according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows one embodiment of a guide assembly 10 according to the present invention. Guide assembly 10 includes a plurality of retainers, or passage guides 12 formed therethrough. Each passage guide 12 includes a first end 14 that extends in a first direction, indicated by arrow 16 , and a second end 18 that extends in a second direction, indicated by arrow 20 . First direction 16 is oriented to generally align with a floor system 22 and second direction 20 extends outwardly therefrom. Although first direction 16 and second direction 18 are shown as generally transverse to one another, other crossing orientations are envisioned and within the scope of the appending claims. First ends 14 are generally aligned to share a common plane preferably below a finish surface 24 of floor system 22 . In one preferred embodiment, the second ends 18 are arranged in two sets. A first set 26 of second ends 18 are generally aligned with, but offset from, a second set 28 of second ends 18 . First set 26 and second set 28 of second ends 18 preferably extend along a wall 30 with the first set 26 being further from wall 30 than second set 28 .
The plurality of passage guides 12 extend through a body 32 of guide assembly 10 such that each passage extends through body 32 between first end 14 and second end 18 . First ends 14 and second ends 18 extend from a first surface 34 and a second surface 36 of body 32 , respectively. During installation, first surface 34 is constructed to be positioned within floor system 22 and second surface 36 is oriented to be generally flush or extend above finish surface 24 of floor system 22 .
Prior to forming floor system 22 about guide assembly 10 , either a plurality of conductors 38 are passed through the plurality of passage guides 12 or the passage guides 12 are connected to conduit means to allow passage of some medium therethrough. Each conductor 38 is isolated from other conductors of the plurality conductors as it passes through an associated passage guide 12 of guide assembly 10 . The plurality of conductors 38 are any of a radiant heating tube 40 , an electrical cable 42 , a computer cable, a potable water tube, a structured wiring cable, a computer cable, a phone cable, or any other conductor that is desired to be passed through floor system 22 . A first end 44 of each conductor 38 extends from first end 14 of a respective passage guide 12 and passes through floor system 22 . First end 44 of each conductor 38 can exit floor system 22 at a location remote from guide assembly 10 or loop through floor system 22 and return to guide assembly 10 and exit floor system 22 thereat. That is, where conductor 38 is a radiant heating tube 40 connected to a heat source with an intended return site located proximate guide assembly 10 , radiant heat tube 40 could enter and exit floor system 22 via guide assembly 10 . Comparatively, if conductor 38 is an electrical cable 42 desired to feed a device such as an outlet, electrical cable 42 does not need to exit floor system 22 at guide assembly 10 . Similarly, if a return site for radiant heat tube 40 is remote from guide assembly 10 , a supplemental guide assembly can be positioned at the desired exit of radiant heat tube 40 and/or electrical cable 42 from floor system 22 .
A second end 45 of each conductor 38 extends from second end 18 of a respective passage guide 12 for connection with an associated system. That is, second end 45 of radiant heat tube 40 extends from second end 18 of guide assembly 10 for connection to a heating system whereas second end 45 of electrical cable 42 extends from second end 18 of guide assembly 10 for connection to an electrical device or an electrical panel. Once the desired conductors 38 have been passed through guide assembly 10 , floor system 22 is formed thereabout. For concrete flooring systems 46 , first ends 44 of plurality of conductors 38 are secured about a length 48 of the conductor 38 to a reinforcing material 50 associated with the concrete flooring system 46 . A plurality of ties 52 secure conductors 38 to reinforcing material 50 in a desired location such that conductors 38 remain in the desired location during the process of forming floor system 22 thereabout. Alternatively, conductors 38 could be secured directly to a subfloor, substrate, or graded surface.
Understandably, floor system 22 , being a concrete floor system, is merely an exemplary application of guide assembly 10 . That is, guide assembly 10 is equally applicable with other flooring systems such as wood/tile/carpet flooring systems. Additionally, the orientation of guide assembly 10 to floor system 22 is also exemplary. That is, as shown in FIG. 1 , second ends 18 of guide assembly 10 extend upwardly from finish floor 24 . Where passage of conductors 38 through a first floor flooring system is desired, guide assembly 10 is rotatable 180 degrees to allow the conductors that are passed therethrough to extend into a joist cavity below the first floor flooring system. As such, guide assembly 10 is applicable to multiple levels of a building structure and provides an efficient and convenient method of passing multiple conductors into and out of any flooring system.
FIG. 2 shows guide assembly 10 removed from flooring system 22 . Body 32 of guide assembly 10 includes a base 54 extending therefrom. Base 54 is constructed to secure guide assembly 10 to a substrate. Base 54 includes a plurality of openings 56 formed therethrough. A plurality of fasteners 58 pass through openings 56 and secure guide assembly 10 to a substrate. As shown in FIG. 2 , fasteners 58 are constructed to engage a gravel base disposed beneath a concrete floor system. Understandably, fasteners 58 could be any suitable fastener such as a nail or screw and constructed to secure guide assembly 10 to a sub-floor system of any material. Alternatively, body 32 could include a plurality of fastener openings or tabs connected thereto such that body 32 could be secured to a surface. In another alternate embodiment, the base 54 may be equipped with tabs to engage joists or studs.
Body 32 of guide assembly 10 includes a groove 60 formed in a first lateral end 62 thereof and a rib 64 extending from a second lateral end 66 thereof. Groove 60 and rib 64 each have a triangular cross-sectional shape such that rib 64 slidingly engages a corresponding groove 60 formed in another guide assembly 10 . Such a construction allows the connection of a plurality of guide assemblies 10 when more passage guides 12 are desired. Understandably, this dove-tailed engagement between rib 64 and a corresponding groove 60 of another guide assembly 10 is merely exemplary. That is, other configurations such as a circular cross-section or other unique cross-sectional shapes are envisioned and within the scope the claims. Alternatively, lateral ends 62 , 66 could have substantially similar cross-sectional shapes. For such a construction, guide assembly 10 would include a connector constructed to engage a respective end of adjacent guide assemblies thereby connecting the adjacent guide assemblies. Similarly, rather than the sliding engagement between multiple guide assemblies, other connection means are envisioned such as mechanical connectors or a snap-fitting engagement between adjacent guide assemblies.
Conductor 38 passes uninterruptedly through passage guides 12 such that first end 44 of conductor 38 extends in first direction 16 along base 54 generally parallel to a floor surface. Second end 45 of conductor 38 extends from second end 18 of passage guide 12 in direction 20 and across first direction 16 . Such a construction provides a guide assembly that is robust and resistant to movement during formation of a finish floor system thereabout. Additionally, guide assembly 10 provides an aesthetically pleasing arrangement of conductors 38 as the conductors exit the floor system.
First ends 14 of passage guides 12 share a common plane, indicated by line 68 , generally parallel to a floor surface. Such a construction ensures that conductors 38 passed from first ends 14 of guide assembly 10 are a relatively uniform depth in a floor system. For heating type systems, this ensures relatively uniform heating of the floor surface. A first set 70 of first ends 14 are a first distance 72 from first surface 34 of body 32 . A second set 74 of first ends 14 are a second distance 76 from first surface 34 of body 32 . Such an orientation allows a user to readily distinguish interconnected conductors. That is, for radiant heating loops, each inlet conductor could extend from a passage guide 12 of first set 70 of first ends 14 and a return associated therewith could pass through an adjacent first end 14 of second set 74 of passage guides 12 . Such a construction is particularly helpful when multiple users are installing multiple loops. That is, each user can independently determine which passage of the plurality of passage guides 12 is required for a return associated with another users heating loop by visual inspection of the guide assembly. Such a construction becomes particularly helpful when multiple guide assemblies are connected and multiple conductors are simultaneously being passed therethrough.
FIG. 3 shows a cross-sectional view of guide assembly 10 along line 3 - 3 of FIG. 2 . As shown in FIG. 3 , second ends 18 of guide assembly 10 extend from body 32 outwardly from floor surface 24 . Conductors 38 pass through passage guides 12 of guide assembly 10 and enter/exit floor system 22 thereat. Second ends 18 of passage guides 12 extend above second surface 36 of body 32 and prevent inadvertent contact with conductors 38 passed therethrough. Alternatively, second surface 36 could be constructed to extend above floor surface 24 to prevent contact of floor finishing tools with second ends 18 of passage guides 12 as conductors 38 passing therethrough. First set 26 of second ends 18 of passage guides 12 is a distance 78 from first surface 34 of body 32 and second set 28 of second ends 18 of passage guides 12 is another distance 80 from first surface 34 . Such a construction allows a user to quickly identify associated conductors after a floor system has been installed. That is, for radiant heating loops, a feed conductor is passed through a passage guide 12 of first set 26 and the associated return is passed through an adjacent passage guide 12 of the second set 28 . Understandably, only one of first ends 14 and second ends 18 need be constructed for operative association of conductor loops passed therethrough. Additionally, by offsetting first and second sets 26 , 28 of second ends 18 , guide assembly 10 provides a compact and visually appealing organization of the plurality of conductors 38 passed therethrough.
Although guide assembly 10 is shown in FIGS. 1-3 as having six passage guides 12 formed therethrough, understandably other numbers of passages are envisioned and within the scope of the claims. That is, guide assembly 10 could be constructed to have any number of passage guides formed therethrough. Additionally, it is understood and within the scope of the claims to provide a guide system having a first guide assembly having a number of passage guides formed therethrough and a second guide assembly having the same or a different number of passage guides formed therethrough. The first and second guide assemblies are connectable to provide a guide system having an application specific number of passage guides. Such a system is highly versatile and limits waste by providing a guide assembly that provides a desired number of passage guides.
FIG. 4 shows an alternate embodiment of a guide assembly 100 according to the present invention. Guide assembly 100 includes a plurality of retainers or passage guides 102 removably connectable thereto. Passage guides 102 are generically referred to as elbows and have a first end 104 that extends in a first direction, indicated by arrow 106 , and a second end 108 that extends in a second direction, indicated by arrow 110 . A body 112 is attached to a base 114 and extends therefrom. A first set of clips 116 are attached to body 112 and a second set of clips 118 are attached to base 114 remote from body 112 . Passage guides 102 individually engage an associated clip pair 120 of first set of clips 116 and second set of clips 118 . Such a construction allows guide assembly 100 to include no more than a desired number of passage guides 102 .
Associated clip pairs 120 engage respective passage guides 102 and secure the position of the passage guide during formation of a floor surface thereabout. Alternatively, it is further understood and within the scope of the claims to construct clip pairs 120 to directly engage a conductor connected to guide assembly 100 . That is, each conductor could be attached to guide assembly 100 without passage guides 102 . Base 114 includes a plurality of openings 122 formed therethrough. Openings 122 are constructed to allow a fastener 124 to pass therethrough. Fasteners 124 secure guide assembly 100 to a subsurface of the floor formed thereabout. Alternatively, it is understood and within the scope of the claims to form openings 122 through body 112 .
Body 112 includes a groove 126 formed therein and a rib 128 extending therefrom. Groove 126 and rib 128 cooperate to allow guide assembly 100 to be securely connected to additional guide assemblies 100 . Such a construction provides a guide assembly that is highly versatile and has only a desired number of passage guides or conductors connected thereto. Similar to passage guides 12 of guide assembly 10 , passage guides 102 of guide assembly 100 are constructed to allow any one of a plurality of different types of conductors to pass therethrough. That is, passage guides 102 are constructed to allow uninterrupted guided passage of radiant heat tubes, potable water tubes, electrical cables, computer cables, structured wiring cable bundles, or the like, through guide assembly 100 . Such a guide system provides a highly versatile, relatively rugged, and visually appealing orientation of the plurality of individual conductors directed by guide assembly 100 .
The guide assemblies 10 , 100 provide a compact and versatile guide assembly. The guide assemblies include a plurality passage guides and are quickly and efficiently attachable to additional guide assemblies. Such a construction provides a multi-passage guide system that can be quickly adapted to provide a desired number of passage guides. Additionally, the structure of guide assemblies 10 , 100 allows the guide assembly to be quickly and securely attached to a sub-floor surface thereby preventing movement of the guide assembly during formation of a floor thereabout. Guide assemblies 10 , 100 provide a compact and esthetically pleasing organization for a plurality of conductors desired to pass through a floor system.
Therefore, one embodiment of the present invention includes a guide assembly that has a body having a first surface and a second surface, wherein the first surface is arranged in a first direction and the second surface is arranged in a second direction that extends outwardly from the first direction. The guide assembly also includes a number of passage guides extending through the body, each passage guide having an inlet generally aligned with the first surface of the body and an outlet generally aligned with the second surface. The passage guides are constructed to allow the passage of a plurality of conduits or conductors therethrough between the first surface to the second surface.
Another embodiment of the present invention includes a guide system includes a first body, a second body connected to the first body, and a plurality of tubes. The tubes are connected to at least one of the first and second bodies and each tube has a first end facing a first common direction and a second end facing a second common direction, wherein the two directions are other than parallel.
A further embodiment of the present invention includes a method of securing a conduit array that includes the step of securing a guide block to a substrate and securing a first conduit to the block such that the first conduit extends in crossing directions from the guide block. The process also includes securing a second conduit to the guide block such that the second conduit extends in directions generally similar to the first conduit.
Yet another embodiment of the present invention includes a guide assembly having a body with first and second portions, wherein the second portion extends from the first portion. A first set of retainers is attached to the first portion of the body in and a second set of retainers is attached to the second portion of the body and is generally aligned with the first set of retainers. The retainers are constructed to retain a plurality of conduits therein.
The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
|
A system for arranging a plurality of conductors includes a guide assembly having a plurality of passage guides. Each of the plurality of passage guides are constructed to guide the passage of a conduit through the guide assembly. The guide assembly is securable to a substrate and constructed to organize individual conduits passing therethrough. The individual conduits communicate any one of a fluid, an electrical power, a hydraulic fluid, or the like through the guide assembly.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to a drafting arrangement for a fine spinning frame, in particular a jet spinning machine.
STATE OF THE ART
The apron drafting systems for fine spinning frames consist of several continuous steel or bottom rollers and a drafting arm for every spinning position, to which arm the spring-loaded top rollers are attached. Such drafting arrangements are known, for example, from the book by Dr. W. Wegener "Die Streckwerke der Spinnereimaschinen" ("Drafting Arrangements of Spinning Machines" Edition 1965, Springer Verlag). An example of such a weighting arm is shown in DE-A-30 25 032. Drafting frame arrangements which were specially designed for jet spinning have been disclosed in U.S. Pat. No. 4,718,225 and U.S. 5,038,553.
During the renewed piecing to a yarn end of a broken yarn, with the yarn end being guided back, for example, through the spinning nozzles of a jet spinning machine and then guided past the drafting arrangement in the manner as is described in DE-A-37 06 728, the yarn section which is guided back is to be guided into the nip line of the rotation pair of output rollers. This so-called depositing of the yarn section should be carried out to the utmost extent in a smooth sequence, so that the yarn end is securely and timely moved to the center of the nip line of the output rollers.
In contrast to the depositing method, which is used in accordance with DE 39 32 666 for example during the piecing in a ring spinning machine, the yarn in a jet spinning machine extends through the nozzle before the depositing, which nozzle is provided with an orifice in or on the nip of the pair of delivery rollers (also known as pair of output rollers). Therefore it is very difficult to keep the yarn in a suitable standby position before the depositing without touching the one or the other rapidly rotating delivery roller. Such a contact is acceptable in ring spinning (cf. DE 39 32 666, FIG. 3). However, in jet spinning (with a substantially higher delivery speed) this is not acceptable.
It is known (e.g., according to DE GBM 18 65 440) to form a roller with conical end sections in order to reduce the lap tendency. This, however, does not have anything to do with the problems relating to renewed piecing.
SUMMARY OF THE INVENTION
The invention now has the object of improving a drafting arrangement of the type mentioned above in such a way that a secure and timely depositing of the yarn section is ensured.
The invention has the further object of improving the renewed piecing (in particular that of a jet spinning machine) with respect to the known methods.
The invention has the advantage that by using simple and inexpensive means it is achieved that the yarn can be held at a suitable standby position before the depositing, thus ensuring the secure and timely depositing of the yarn section. Further advantages arise from the description below in which the invention is outlined in greater detail by reference to the embodiments shown in the Figures, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an arrangement of a nozzle body with respect to the output rollers of an apron drafting arrangement;
FIG. 2 shows the same arrangement as in FIG. 1 from direction A;
FIG. 3 shows a section through the pressure roller;
FIG. 4 schematically shows a spinning position (including a winder unit) of a jet spinning machine;
FIG. 5 schematically shows the main draft zone of the drafting arrangement of FIG. 1, in combination with a yarn handling device situated in a standby position;
FIG. 6 shows the arrangement in accordance with FIG. 5 as seen in the direction of arrow B;
FIG. 7 shows the arrangement of FIG. 5 shortly after initiation of the yarn depositing movement;
FIG. 8 shows the arrangement shown in FIG. 7 in the direction of arrow B;
FIG. 9 shows the arrangement in accordance with FIG. 5 after the conclusion of the yarn depositing movement;
FIG. 10 shows the arrangement shown in FIG. 9 as seen in the direction of arrow B; and
FIGS. 11 to 16 show three further embodiments.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 to 3 the same reference numerals are used for the same elements. FIG. 1 shows the injector nozzle 1 of a jet spinning machine pertaining to the output rollers 2 and 3 of an apron drafting system (not shown). The lower roller 2 of the drafting arrangement as shown on the lefthand side is a stub-like steel cylinder in this embodiment. However, it may also be a continuous steel cylinder which extends in the known manner over several spinning positions of the spinning machine.
The upper or pressure roller 3 is attached to a weighting arm (not shown). It encompasses a rigid axle 9, FIG. 3, and a cylindrical hollow body 11 which is rotatably mounted on axle 9 by means of bearings 8, 8'. Body 11 is provided with a rubber-coated cover 4.
A cone-like cap 5 is attached on axle 9 by means of a screw 10. At its free end section, cap 5 has the shape of a truncated cone, as can be seen in FIG. 3. The part of the cap which has the form of a truncated cone changes into the cylindrical part which is adjacent to roller body 11 without actually touching it. This is secured by means of a fixing element 12 of cap 5, which element is connected with axle 9 by means of screw 10. Cap 5 and axle 9 could be made from one piece.
Transition zone 5' of the conic frustrum-like surface, where it changes into the cylindrical area, is rounded off. The tapered surface of the cap could, however, be provided in its section with a rounding off, e.g. it may have a parabolic form.
It is now assumed that by depositing a yarn at the pair of rollers 2, 3 a renewed piecing process is to be carried out. Yarn section 6 has been guided back by the twist nozzle (not shown) and the injector nozzle 1. As has been described in greater detail in our German patent application No. 4223956.7 and U.S. patent application Ser. No. 07/919,876, the yarn section 6 is received by a suction nozzle 7 at a position between injector nozzle 1 and the output rollers 2 and 3. Thereafter it is guided laterally around the drafting arrangement and subsequently held in a defined standby position. At a time determined by a control mechanism the yarn section 6 is pulled into the nip of the pair of rollers 2 and 3 by the suction nozzle. In the standby position the relatively rigidly tensioned yarn section 6 is guided-onto a cone-like cap 5. Due to a movement of the suction nozzle into the intermediate space in front of the output pressure roller 3 and the upper apron of the drafting arrangement, a loop of the yarn section 6 is guided by cap 5 into the nip line of output rollers 2 and 3.
As cap 5 does not rotate with pressure roller 3, but is rigidly screwed onto its axle, abrasive stress on the yarn section 6 which might occur by the rotating output rollers 2 and 3 during the phase of the lateral excursion next to the drafting arrangement is prevented.
The larger outer diameter portion of the cone-like cap 5 has at least the same size of or it is preferably even larger than the outer diameter of the subsequent portion of the rubber coating 4 of pressure roller 3.
The arrangement allows a timed depositing of the yarn section 6, i.e., the yarn end can be guided at the right time to the site designated for the yarn connection in the yarn connecting or piecing process, without allowing a premature connection of the drafted fibers to occur in the operating drafting arrangement.
It is to be understood that the above-mentioned cap 5 is not only suitable for so-called apron drafting systems, but also for other drafting arrangements such as the certain drafting arrangements disclosed in the above-mentioned book by Wegener, page 315).
As cap 5 can be easily removed, the pressure rollers can still be easily exchanged for maintenance purposes.
A further possibility is to provide the rotating portion of pressure roller 3 (e.g. the hollow body) with a lateral cap 5. This solution, however, is preferably not taken into account because in such a case it is not possible to prevent the mentioned abrasive strain on yarn section 6, even if the cap material were highly polished. In addition, the production expenditure would rise because the pressure roller 3 with the rubber-coated cover 4 would have to have improved concentric running properties so as to prevent periodic yarn faults. Adherence to these requirements is made more difficult by the attachment of a cap.
The rubber-coated cover 4 in accordance with FIG. 2 comprises a central zone 4A with a diameter D and two end zones 4B, 4C with smaller diameters d 1 , d 2 . Zone 4B is adjacent to cap 5. The nip line of the pair of delivery rollers 2, 3 is formed between the roller 2 and the central zone 4A of the cover. The largest diameter portion of cap 5 can be of the same size as the diameter D of the central region 4A, i.e., it can exceed end zone 4B.
FIG. 4 schematically shows a single spinning position of a jet spinning machine (e.g., in accordance with EP 131 170 or EP 372 255). The spinning position comprises a drafting arrangement 40 with a pair of input rollers 37, a central pair of rollers 38 (which is provided with aprons) and a pair of delivery rollers 39. A condenser 35 is situated in front of the pair of input rollers 37 and forms a part of the sliver stopper in accordance with EP 353 575. The elements of FIG. 4 are only shown schematically more or less separated from one another so as to improve the recognizability of the individual components.
A yarn spinning nozzle body 20 is provided behind the drafting arrangement 40, which body may be arranged, for example, in accordance with DE 40 23 985 or EP 489 686. The yarn wind-up unit 50 comprises a friction roller 44 and a holder 46 which carries a cross-wound bobbin 48. Usually, yarn spun by nozzle body 20 is drawn off by the pair of draw-off rollers 42 and supplied to the winder unit 50 for forming a package of yarn on the bobbin.
In the arrangement shown, it is assumed that the yarn was broken during the spinning, such that it has to be pieced up again with a new sliver end. As shown, the yarn has been withdrawn from the bobbin package and has been threaded by means of a handling device (not shown fully--see, for example, EP 467 159) with a suction nozzle 41 through a pair of draw-off rollers 42 with the draw-off rollers not in contact with one another for this purpose. Instead of retrieving yarn from the bobbin package, it is possible to use an auxiliary yarn for renewed piecing which can be thrown onto a bobbin case carried by holder 46 after the successful piecing. The yarn to be pieced can be guided back by the nozzle body 20, e.g. in accordance with a method of EP 433 832, according to which the yarn end is taken up again by the suction nozzle 41.
FIGS. 5 to 10 shows a process for renewed piecing in a spinning position in accordance with FIG. 4 with a drafting arrangement and a roller in accordance with the present invention. The nozzle body is shown with reference numeral 20, the pair of delivery rollers 22, 23 and the pair of apron rollers 24, 25. The aprons are indicated with numerals 26, 27. The upper or pressure roller 23 of the pair of delivery rollers has a "conical" cap 28 in accordance with the present invention. The location of the inlet orifice of the nozzle body in the vicinity of the drafting arrangement is indicated in FIGS. 6, 8 with 10 and 21.
The location of the orifice of the suction nozzle is indicated with reference numeral 29. The suction nozzle is situated laterally from the standby position as shown in FIGS. 5, 6. The yarn section 6 extends from the nozzle body 20 laterally (as viewed from above) nearly parallel to the nip line of the pair of delivery rollers 22, 23 FIG. 6 and is guided by the conical end section of cap 28. FIGS. 6, 8 and 10 are spatially distorted with respect to the actual arrangement, because it is not possible to represent the three-dimensionality of the yarn course in these illustrations. In these Figures the cylindrical areas of cap 28 are shown schematically "extended" to the left in order to stress that there is no contact of the yarn with cover 4. The actual embodiment is shown more realistically in FIG. 3.
Cap 28 is arranged in such a way that the yarn section being guided laterally does not come into contact with any rotating part of the drafting arrangement (in this phase). At this position the yarn can be held without the yarn being abraded by the rotating rollers or without an additional twist being produced in the yarn. The drawing off of the yarn captured in the suction nozzle can be initiated already during the time when the suction tube is holding the yarn end in the standby position, namely by the pair of draw-off rollers 42 situated behind the nozzle, FIG. 4. The yarn is stretched tight by said drawing off.
FIGS. 7 and 8 show an intermediate phase in which the suction nozzle 41 is moving in a direction towards the central plane or path of sliver delivery through the drafting arrangement. A loop F, FIG. 8, is formed on cap 28. The yarn still does not touch any of the rotating parts, so that the position is still "precisely" defined. Loop F is continuously "shortened" by said drawing off. At a given time the "apex" of said yarn loop moves over the transitional zone into the nip line of the pair of delivery rollers. The loop is thereafter gradually removed out of the suction nozzle 41 by the drawing off of the yarn, so that at the end of the depositing process the yarn enters the nip line in straight alignment with the normal path of sliver delivery, FIG. 10.
In this case the transitional movement of the yarn from cap 28 to the surface of pressure roller 23 is facilitated by the end zone 4D of the cover also being formed cone-like. The smallest diameter end of the conical zone 4D can be smaller than the diameter of the cylindrical portion of cap 28. As soon as the yarn comes into contact with the cover 4 of the pressure roller, the cover exerts a conveying effect thereon. This effect arises on delivery speed as soon as the yarn is inserted into the nip line of the delivery rollers. The length or arrangement of cap 5 or 28 is selected such that for a given position of nozzle body 20 with respect to the drafting arrangement, a yarn guided by the manipulating nozzle can extend around the cap without touching any rotating part of the drafting arrangement.
FIGS. 5 to 10 show that the yarn section 6 actually only touches a portion of the conical surface, i.e., the portion shown facing roller 22. The portion of this surface which faces away from the roller 22 actually does not have any effect. For this reason this portion would not necessarily have to be provided with a yarn guiding surface. For example, it would not have to be tapered. Cap 28, however, is nevertheless preferably arranged rotationally symmetrically, because in this case it can be attached without taking any special notice of its angular position with respect to the mounting axis or the pressure roller. Furthermore, it constitutes an inexpensive solution to the problem solved by the invention.
The controlled movement of the suction nozzle 7 or 41 from a lateral position to the central plane of the drafting arrangement is preferably carried out so fast that the yarn loop F is extended the length of the gap between cap 5 or 28 and the cover 4. This serves to aid in preventing the yarn section 6 from getting caught in this gap.
FIGS. 11 to 16 illustrate three further embodiments, which show that the cap does not necessarily have to be provided on the axle of the pressure roller. The corresponding components of the embodiment described with reference to FIGS. 5 to 10 have the same reference numerals as corresponding components in FIGS. 11 to 16. Alternative components are exclusively limited to the cap and its carrier. The attachment of the cap on the carrier is not made within the pressure roller but on a surface component of the cap, which is not touched by the yarn during the depositing movement.
In the embodiments shown in FIGS. 11 and 12 cap 105 is carried by an arm 106 which is mounted on a service robot (not shown; see however EP 421 152) as an element of a handling device. Cap 105 can be delivered to pressure roller 3 during an operating process by means of said arm 106.
In order to simplify the positioning of cap 105 with respect to pressure roller 3, cap 105 can be provided with a socket 107 (FIG. 12) which receives an end part of axle 9. This, however, is not essential. The small gap S between cap 105 and cover 4 can be bridged, as was mentioned above, by the movement of suction nozzle 7 or 41. In the present embodiment cap 105 only has to be provided once for all spinning positions serviced by the service robot.
Cap 105 could be made in one piece with arm 106. However, preferably it is made separately and attached to arm 106 in the area 108 (FIG. 12), for example.
The embodiments of FIGS. 13 and 14 show a cap 115 which is carried by an arm 116. Arm 116 is attached to the weighting arm (not shown) of the drafting arrangement. The cap can either be made in one part with arm 116 or be attached thereto.
FIGS. 15 and 16 show a further embodiment which is only distinguished from the embodiment in accordance with FIGS. 13 and 14 in that carrier arm 117 is not attached to the weighting arm of the drafting arrangement, but that it is attached by means of a plate 118 to a part (not shown) of the machine frame in the vicinity of the nozzle body.
|
An apparatus and method for guiding a broken thread end in a yarn spinning machine into a position in readiness for piecing wherein the broken thread end is retrieved from a bobbin, routed through a yarn spinning mechanism, guided into the nip of a pair of rollers of an operating drafting apparatus without abrasion of or interference with the yarn end during the guiding of the yarn end and wherein the yarn end is deposited in a position in the drafting apparatus such that the yarn end is controllably withdrawn from the drafting apparatus through the spinning mechanism and pieced or joined with a new sliver as the yarn end is withdrawn.
| 3
|
RELATED APPLICATION
[0001] This patent arises from a continuation of U.S. patent application Ser. No. 09/955,691, filed Sep. 19, 2001, which is, in turn, a continuation-in-part of U.S. patent application Ser. No. 09/226,521, which was filed on Jan. 7, 1999. U.S. patent application Ser. No. 09/955,691 is hereby incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to detection of media links (such as URLs) which are embedded in programs that are transmitted by television and/or radio signal transmission sources, such as television and/or radio networks, local broadcasters, cable operators, video servers, Web sites, and the like.
BACKGROUND
[0003] As used herein, programs mean commercials, regular programming material, documentaries, and/or the like, which are transmitted for reception by televisions, radios, computers, and other equipment provided with video and/or audio tuners. Also as used herein, media links include URLs embedded in video and/or audio, surrogate URLs, or any other links in video and/or audio that link a content recipient to content provided by a content provider (such as a Web site) or to content provided elsewhere in the video and/or audio whether such content is stored in cache or not. A surrogate URL, for example, may be an ASCII or other code that is embedded in content and that may be used to look up an URL for linking to content. An example of a media link that links a content recipient to content provided elsewhere in the video and/or audio is a trigger that, when received from the video and/or audio, causes content, which was previously transmitted in the video and/or audio and cached by the receiver, to be displayed to the content recipient.
[0004] Programs are transmitted by transmission sources through the use of satellites, over the air by way of transmitting antennas, or over cables such as wires or optical fibers. These transmission sources can be networks, local broadcasters, satellite broadcasters, video servers, Web sites, cable programmers, and the like.
[0005] It is frequently desirable to detect the transmission of programs by the transmission sources. For example, in preparing program rating reports, the receivers of statistically selected panelists are metered in order to determine at least (i) the channels to which the receivers are tuned and (ii) the times during which the receivers are tuned to those channels. The resulting tuning data are extrapolated over the population as a whole, or over relevant segments of this population, in order to report ratings. However, because the identities of programs carried in the channels reported in the tuning data cannot always be inferred from the tuning data, it is necessary to determine, or at least verify, the identity of the programs transmitted in the channels and during the times covered by the tuning data.
[0006] As another example, advertisers often desire to verify certain information regarding the transmission of their commercials by transmission sources. This information includes a verification (i) that the commercials were actually transmitted, (ii) that the commercials were transmitted in their entirety, and (iii) that the commercials were transmitted in the correct time slots and in the correct channels. This information allows advertisers to determine whether they received the value for which they contracted with the relevant transmission sources.
[0007] As yet another example, advertisers often desire to ascertain the advertising strategies of competitors. These advertising strategies may be discerned from the types of advertisements run by competitors, the competitors' expenditures on such advertisements, the media chosen to carry such advertisements, and the like.
[0008] Accordingly, systems have been developed in order to identify transmitted programs. For example, in connection with reporting program ratings, a program verification system known as the AMOL (Automated Monitoring of Line-up) program verification system is operated by the assignee of the present invention. In this AMOL program verification system, a code is inserted into the vertical blanking interval of programs. Monitoring equipment at sites located in relevant geographical areas read the AMOL codes from transmitted programs and detect the channels in which these programs are transmitted as well as the times during which these programs are transmitted. Accordingly, the AMOL program verification system is able to verify that particular programs were transmitted in corresponding particular channels, during corresponding particular time slots, and for particular corresponding amounts of time. The verified program/channel relationship, coupled with the channel tuning data acquired from the receivers of the statistically selected panelists, are used to determine the programs to which these receivers were tuned.
[0009] As another example, the assignee of the present invention operates a service known as the Monitor Plus service in which sets of commercial monitoring equipment are placed in selected geographical monitoring areas. The sets of commercial monitoring equipment tune to each of the channels available in the corresponding geographical areas and extract broadcast signatures from commercials carried in these channels. The channels, times, and dates of the broadcast signature extractions are also noted. The extracted broadcast signatures are compared to previously extracted reference signatures. In each geographical monitoring area, these reference signatures are stored in a reference signature library along with identification information regarding the commercials from which the reference signatures were extracted.
[0010] Because there are typically many reference signatures stored in a reference signature library, and because comparing the broadcast signatures to all such reference signatures would require a substantial amount of time, hash codes are used to focus the search such that the search finds only those reference signatures which are potential matches to the broadcast signatures. The hash codes are computed from one or more characteristics, such as luminance, of the broadcast signatures so that only those reference signatures producing similar hash codes within some range are compared to the broadcast signatures.
[0011] When broadcast signatures match reference signatures, the identities of the transmitted commercials are known from the identity information stored with the matching reference signatures. Also, the channels, times, and dates of commercial transmissions are known from the matching broadcast signatures. The sets of monitoring equipment can also detect the length of the commercial as transmitted by comparing multiple broadcast signatures and multiple reference signatures extracted from the same commercial. Accordingly, reports can be generated that permit advertisers to verify that their commercials have been run in the channels, on the days, in the time slots, and for the durations desired, and/or to permit advertisers to ascertain the advertising strategies of their competitors.
[0012] When broadcast signatures do not match reference signatures, however, it may be possible that a new commercial has been transmitted for which there are no reference signatures stored in the library. In this case, the extracted broadcast signatures corresponding to each possibly new commercial are stored for later transmission to a central facility where the possibly new commercial is viewed and identified by an attendant. This viewing and identification process is usually referred to as new commercial labeling. Once identified, the new commercial's broadcast signatures are converted to reference signatures and are stored in the reference signature libraries.
[0013] Clustering is performed in each geographical monitoring area so that a geographical monitoring area does not send the same new commercial multiple times to the central facility for new commercial discovery. During clustering in a geographical monitoring area, the broadcast signatures of each possibly new commercial are compared to the broadcast signatures of the other possibly new commercials in order to detect duplicates. Duplicates are not transmitted to the central facility. Accordingly, the efficiency of new commercial discovery is increased because only one instance of each possibly new commercial is transmitted to, and processed by, the central facility. However, because an instance of a possibly new commercial may be received at the central facility from more than one geographical monitoring area, clustering is again performed at the central facility prior to each initiation of new commercial discovery.
[0014] Furthermore, it is expected that other appliances, such as computers and set top boxes, will be equipped with tuners so that these appliances can display video and/or audio, such as television and/or radio programs. It is also expected that this video and/or audio will contain media links. Accordingly, if a user of a computer, digital television, set top box, or other video and/or audio receiving device is viewing a program of interest, and desires to access other information associated with the program, the user can click on the program. Clicking on the program will cause a media link, which is embedded in the program, to be sent back to a Web site or other content provider with the result that additional information will be downloaded to the user's appliance. In the case where the media links are self-activating, such as where the media link is a trigger, clicking on the program need not be required. Instead, the media link, when detected by the video, audio, and/or data receiving device, automatically causes the display of ancillary content which, for example, may have been previously transmitted in the video, audio, and/or data signal and cached in the receiving device or in auxiliary equipment.
[0015] Because these media links will likely uniquely identify the programs in which they are used, the present invention is directed to an arrangement for detecting these media links in order to determine the identities of the programs in which the media links are embedded. Accordingly, the present invention is useful in an AMOL type system, a Monitor Plus type system, or in other systems in which the identity of a transmitted program is desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features and advantages of the present invention will become more apparent from a detailed consideration of the invention when taken in conjunction with the drawings in which:
[0017] FIG. 1 illustrates an example metering system having monitoring equipment located at a monitoring site and a central facility located remotely from the monitoring site;
[0018] FIG. 2 illustrates in flow chart form one embodiment of a program that may be executed by the monitoring equipment at the monitoring site of FIG. 1 ;
[0019] FIGS. 3 and 4 illustrate in flow chart form an alternative embodiment of a program that may be executed by the monitoring equipment at the monitoring site of FIG. 1 ; and,
[0020] FIG. 5 illustrates in flow chart form a clustering program that may be executed by the monitoring equipment at the monitoring site and/or by the computer at the central facility of FIG. 1 .
DETAILED DESCRIPTION
[0021] As shown in FIG. 1 , monitoring equipment 10 is located at a monitoring site 12 and includes a tuner 14 which tunes to a channel contained in a signal received by a signal acquisition device 16 . The signal acquisition device 16 may be a modem, a satellite dish or other antenna, or the like and acquires signals transmitted by transmission sources. The signal carried in the channel to which the tuner 14 is tuned is supplied to a meter 17 which includes a media link detector 18 and a signature extractor 20 . The media link detector 18 is arranged to detect media links in a manner which is similar to present metering equipment that detect other ancillary codes, such as AMOL codes. In the present case, however, the media link detector 18 is arranged to decode the signal carried in the channel to which the tuner 14 is tuned in order to detect a media link. When the media link detector 18 detects a media link, it causes the media link to be stored in a log 22 .
[0022] In the event that a media link is not contained in a program which is carried in the channel to which the tuner 14 is tuned, the signature extractor 20 extracts one or more broadcast signatures from the program. Broadcast signatures are likewise stored in the log 22 . Signatures may be extracted in a manner disclosed in U.S. Pat. No. 4,677,466. This patent discloses example conditions which initiate signature extraction. However, although specific conditions are disclosed, it should be understood that other conditions may be used to initiate signature extraction. For example, a signature may be extracted from each nth frame of a program. Moreover, any suitable techniques may be used to collect the data that form the signatures.
[0023] A clock 24 is associated with the log 22 so that the time and date that each media link is detected by the media link detector 18 may be stored along with the corresponding media link. Similarly, the time and date that each broadcast signature is extracted by the signature extractor 20 may be stored along with the broadcast signature. Also, the channel to which the tuner 14 is tuned at the time that a media link is detected by the media link detector 18 or a signature is extracted by the signature extractor 20 may be stored in the log 22 along with the corresponding media link or broadcast signature.
[0024] Periodically, the data stored in the log 22 is transmitted by communication equipment 26 from the monitoring site 12 to a remotely located central facility 28 over a communication medium 30 . The communication equipment 26 may be arranged to periodically transmit the data stored in the log 22 to the central facility 28 . Alternatively, the communication equipment 26 may be arranged to transmit the data stored in the log 22 when the log 22 has a predetermined amount of data stored therein. As a still further alternative, the communication equipment 26 may be arranged to respond to polls from the central facility 28 in order to initiate the transfer of data to the central facility 28 . Still other alternatives and combinations of alternatives are possible.
[0025] The communication medium 30 may be any communication medium which supports the transfer of information between remote locations. For example, the communication medium 30 may be a public telephone network, air accessed by radiating antennas such as satellite, cellular, and terrestrial antennas, over cables such as the RF return over a cable plant, the Internet, or the like.
[0026] A computer 32 is located at the central facility 28 . The computer 32 may be arranged to identify programs from the media links and broadcast signatures transmitted to it by the communication equipment 26 . For example, in the case of media links, the computer 32 may be arranged to compare the media links received from the monitoring site 12 to a library of media links which contain both the media links and the titles and/or other identifying information corresponding to the programs from which the media links were detected by the media link detector 18 . Accordingly, when the computer 32 is provided with a media link from the monitoring site 12 , it can identify and/or verify the program which contains that media link and which was transmitted by a transmission source. The computer 32 can also determine, if desired, that the program containing the media link was transmitted at a particular time, on a particular day, and on a particular channel from the channel, time, and date information transmitted to the central facility 28 along with the detected media link.
[0027] In some cases, the programs may be completely identified from the media link itself. In this case, there is no need to use the look up table in the identification process. In other cases, particularly where a program has been transmitted for the first time, no information is provided in the look up table from which the program may be identified. In this case, the media link may be used to access the Web site or content associated with the media link in order to discover the identity of the program, or the program may be viewed by personnel of the central facility 28 in order to discover the identity of the program. Then, the identity of the program may be entered into the look up table under the media link for future identifications.
[0028] The computer 32 may also be arranged to identify and/or verify programs which do not contain media links. For example, the computer 32 may be arranged to compare the broadcast signatures received from the monitoring site 12 to a library of reference signatures which contain both the reference signatures and the titles and/or other identifying information corresponding to the programs from which the reference signatures were extracted. Accordingly, when the computer 32 is provided with broadcast signatures from the monitoring site 12 , it can identify programs and/or verify the transmission of programs by matching these broadcast signatures with the reference signatures stored in the reference signature library. The computer 32 can also determine, if desired, that the programs containing the extracted broadcast signatures were transmitted at particular times, on particular days, and on particular channels from the channel, time, and date information transmitted to the central facility 28 along with the extracted broadcast signatures.
[0029] Alternatively, the computer 32 may use both detected media links and extracted broadcast signatures, where available from the same program, in order to increase certainty that a program is properly identified and/or verified. As a still further alternative, the computer 32 may identify and/or verify a program from the media links in the event that the computer 32 is unable to first identify and/or verify the program from the extracted broadcast signatures.
[0030] The meter 17 operates in accordance with a software routine 50 shown in FIG. 2 . The software routine 50 , at a block 52 , determines from the output of the tuner 14 whether a program of interest is received. For example, the software routine 50 at the block 52 may operate in accordance with the above mentioned U.S. Pat. No. 4,677,466 in order to determine the start of a program of interest. (Alternatively, the software routine 50 at the block 52 may be arranged to simply detect when the tuner 14 is on and is tuned to a channel in which there is content. In this case, the output of the tuner 14 is continuously monitored for media links, and broadcast signatures are extracted from the output of the tuner 14 on a continuous basis.) A program of interest may be a commercial, regular programming material, a documentary, and/or the like.
[0031] If a program of interest is not detected at the block 52 , the software routine 50 waits for a program of interest. However, if a program of interest is detected, the software routine 50 at a block 54 determines whether a media link is detected by the media link detector 18 from a segment of the current program. For example, this segment may have a determinate length, such as n frames of the current program. Alternatively, this segment may have an indeterminate length determined by conditions of the program signal as disclosed in the above mentioned U.S. Pat. No. 4,677,466.
[0032] If a media link is detected from the current segment of the current program at the block 54 , the media link is logged at a block 56 . Because a media link is detected in the program of interest, it may not be necessary to save any broadcast signatures which may have been extracted from the current program prior to the time at which the media link is detected. If so, the software routine 50 at a block 58 deletes from the log only the broadcast signatures extracted by the signature extractor 20 from the current program, and program flow thereafter returns to the block 52 to wait for the next program of interest.
[0033] On the other hand, if a media link is not detected from the current segment of the current program at the block 54 , the software routine 50 at a block 60 extracts a broadcast signature from the current program appearing at the output of the tuner 14 . The software routine 50 at a block 62 logs the broadcast signature extracted by the signature extractor 20 at the block 60 .
[0034] The software routine 50 then determines at a block 64 whether an end to the current program is detected. For example, the software routine 50 at the block 52 may operate in accordance with the above mentioned U.S. Pat. No. 4,677,466 in order to determine the end of the current program. If an end to the current program is not yet detected, program flow returns to the block 54 in order to search for a media link from the next segment of the current program.
[0035] On the other hand, if an end of the current program is detected at the block 64 , program flow returns to the block 52 in order to process a next program. In this case, the current program contained no media link and the current program will be identified by the computer 32 from the extracted broadcast signatures.
[0036] Instead of identifying a program from a media link, the media link may be used to better focus the search for reference signatures which match broadcast signatures. This use of a media link is particularly valuable in those instances where the media link is not unique, i.e., where the media link is used in more than one program and, therefore, does not uniquely identify a program. In addition to a media link, other information which is ancillary to the program content contained in the program signal, such as closed captioning information, may be used for this reference signature search focusing. Accordingly, media links, closed captioning information, or other such ancillary information may be referred to herein as content ancillary information (CAI).
[0037] A software routine 100 , which is illustrated in FIGS. 3 and 4 , uses content ancillary information in order to focus the search for reference signatures that are to be compared to broadcast signatures during the process of identifying a program. The communication equipment 26 may employ, in addition to a transmitter, a computer in order to execute the software routine 100 .
[0038] The software routine 100 , at a block 102 , determines from the output of the tuner 14 whether a program of interest is received, as before. If a program of interest is not detected at the block 102 , the software routine 100 waits for a program of interest. However, if a program of interest is detected, the software routine 100 at a block 104 determines whether content ancillary information is detected by the media link detector 18 from a segment of the current program. If content ancillary information is detected from the current segment of the current program at the block 104 , the content ancillary information is logged at a block 106 .
[0039] On the other hand, if content ancillary information is not detected from the current segment of the current program at the block 104 , or after the content ancillary information is logged at a block 106 , the software routine 100 at a block 108 extracts a broadcast signature from the current segment of the current program. The software routine 100 at a block 110 logs the broadcast signature extracted by the signature extractor 20 at the block 108 .
[0040] The software routine 100 then determines at a block 112 whether an end to the current program is detected. If an end to the current program is not yet detected, the software routine 100 at a block 114 waits for the next segment. When the next segment occurs, program flow returns to the block 104 . When the end of a current program is detected at the block 112 , a set of broadcast signatures has been extracted and stored for that program. Also, content ancillary information, if detected, is also stored for that program. This set of broadcast signatures is compared to reference signatures stored in a reference signature library as described below in an attempt to identify the program corresponding to this set of broadcast signatures.
[0041] Thus, if an end of the current program is detected at the block 112 , the software routine 100 at a block 116 determines whether content ancillary information was detected in the program just processed by the blocks 102 - 114 . If content ancillary information was detected in the program just processed by the blocks 102 - 114 , a search of the reference signatures stored in the reference signature library is made at a block 118 in order to find reference signatures corresponding to the content ancillary information. Such reference signatures were previously extracted from a program containing the same content ancillary information and were loaded into the reference signature library in association with the corresponding content ancillary information.
[0042] If content ancillary information was not detected in the program just processed by the blocks 102 - 114 , hash codes corresponding to the broadcast signatures extracted at the block 108 may be computed at a block 120 . A search of the reference signatures stored in the reference signature library is made at a block 122 in order to find reference signatures corresponding to the hash codes computed at the block 120 . (Alternatively, the broadcast signatures extracted at the block 108 may be compared to all reference signatures in the reference signatures library.)
[0043] The reference signatures found at the block 118 or at the block 122 are compared at a block 124 to the broadcast signatures extracted from the program at the block 108 . If a sufficient match is found at the block 124 , the identification of the program stored in the reference signature library along with the matching reference signatures is saved at a block 126 for later transmission to the central facility 28 . The time at which the program was received, the length of the program as detected, the channel in which the program was detected, and other relevant information may also be stored at the block 126 along with the program identification.
[0044] If a match is not found at the block 124 , the broadcast signatures extracted from the program at the block 108 and the content ancillary information, if any, for the program are saved at a block 128 for later clustering and transmission to the central facility 28 so that the program can be identified during new program discovery. The time at which the program was received, the length of the program as detected, the channel in which the program was detected, and other relevant information may also be stored at the block 128 along with the broadcast signatures extracted at the block 108 and the content ancillary information, if any, detected at the block 104 . After the identification is saved at the block 126 , or after the broadcast signatures and content ancillary information are saved at the block 128 , program flow returns to the block 102 to process the next program of interest.
[0045] Content ancillary information can also be used during clustering performed by the monitoring equipment 10 and/or by the central facility 28 in order to cluster broadcast signatures corresponding to unknown programs. Unknown programs are those programs whose broadcast signatures did not favorably compare to any reference signatures stored in the reference signature library and/or which did not contain a program identifying code such as a media link. Accordingly, to implement clustering, the computer employed in the communication equipment 26 and/or the computer 32 of the central facility 28 may execute a software routine 200 shown in FIG. 5 .
[0046] The time for clustering is determined at a block 202 . For example, clustering by the monitoring equipment 10 and/or by the computer 32 may be performed periodically, such as once a day, or in response to an event such as a poll or an instruction from a user, or the like. When it is time for clustering as determined at the block 202 , the broadcast signatures corresponding to one unknown program are compared to the broadcast signatures corresponding to other unknown programs at a block 204 based upon the content ancillary information associated with each set of broadcast signatures. Thus, all sets of broadcast signatures corresponding to the same first content ancillary information (e.g., CAI 1 ) are compared to one another. Duplicates are then eliminated so that only one set of broadcast signatures corresponding to content ancillary information CAI 1 is kept. Similarly, all sets of broadcast signatures corresponding to the same second content ancillary information (e.g., CAI 2 ) are compared to one another, and duplicates are then eliminated so that only one set of broadcast signatures corresponding to content ancillary information CAI 2 is kept. This process is repeated for each of the remaining content ancillary information. Then, each set of broadcast signatures which did not have a content ancillary information associated therewith is compared at a block 206 to all other remaining sets of broadcast signatures, including those remaining sets of broadcast signatures having content ancillary information associated therewith, and any duplicates are eliminated. As a result of the processing at the blocks 204 and 206 , the remaining sets of broadcast signatures are unique and the software routine 200 ends. As a result, it is necessary to view an unknown program only once during new program discovery.
[0047] Certain modifications of the present invention have been discussed above. Other modifications will occur to those practicing in the art of the present invention. For example, the tuner 14 may be a tuner which tunes to a single channel so that a tuner 14 is required for each channel to be monitored. In this case, a multiplexer may be arranged to multiplex signals from some or all of the instances of the tuner 14 to the meter 17 so that each multiplexed output of the instances of the tuner 14 is processed in turn by the monitoring equipment 10 . Alternatively, instead of multiplexing, each tuner 14 may be provided in its own set of monitoring equipment 10 . On the other hand, the tuner 14 may be a scanning tuner for tuning to each of the channels available at the monitoring equipment 10 , or the channels may be divided up between several scanning tuners or between a combination of scanning tuners and non-scanning tuners.
[0048] Also, as discussed above, the signature extractor 20 is arranged to extract signatures from the programs to which the tuner 14 is tuned. However, other program identifying data may be captured instead of, or in addition to, signatures. For example, AMOL codes may be detected. Also, the monitoring equipment may be arranged to prompt audience members to manually input a program identification in the event that a media link is not found in a program. In this case, the non-media link program identifying datum is the manually entered program identification.
[0049] Moreover, it is not necessary to delete from the log those broadcast signatures which are extracted from a program from which a media link is also detected. In this case, the block 58 may be eliminated.
[0050] Furthermore, as described above, the meter 17 operates in accordance with the software routine 50 . However, the meter 17 may be implemented in hardware, in a combination of software or hardware, or the like.
[0051] In addition, detected media links as described above may be used to identify the programs received by a receiver and/or to verify that the programs have been transmitted as intended. However, the detection of media links may have many other uses. For example, the detection of media links also may be used to verify that the correct media links were transmitted in the correct programs, over the correct channels, at the correct times, in the correct numbers, etc.
[0052] Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved.
|
A detection apparatus includes a tuner tuned to the program and a meter coupled to the tuner and arranged to detect content ancillary information from the program tuned by the tuner. The content ancillary information may be a media link, closed captioning information, or the like. The meter may also be arranged to extract a broadcast signature from the program. A comparator compares the broadcast signature to a reference signature selected from a library of reference signatures based upon the content ancillary information. Broadcast signatures from unknown programs may be clustered at least partially on the basis of the content ancillary information.
| 7
|
FIELD OF THE INVENTION
The invention relates to a carpet face yarn having the stain resistant properties of polyolefin based yarns and the resiliency of polyamide based yarns.
BACKGROUND
Carpets for home and industrial use are typically made from synthetic or natural fibers such as nylon, polyester, polyolefins, acrylics, rayon, cellulose acetate, cotton and wool. Of the foregoing, synthetic carpets tend to be more commercially acceptable and can be used for a wider variety of applications.
Of the synthetic fibers, nylon is principally the polymer of choice for carpets. However, nylon is not without its drawbacks. Notably, nylon carpeting is susceptible to developing static electric charges and thus must be treated to reduce the build-up of static charges. Another disadvantage of nylon carpeting is that it will readily stain. Accordingly, nylon carpets are usually treated to reduce their staining tendencies. These treatments do not, however, prevent all staining, nor do they last for the life of the carpet.
On the other hand, carpets made from polyolefins, such as polypropylene, are very resistant to staining and are naturally antistatic. However, polypropylene is a more rigid and less resilient fiber and will not generally maintain its appearance or shape under prolonged or heavy use, or after repeated deformations.
An object of the invention therefor is to provide an improved carpet face filament.
Another object of the invention is to provide a carpet face filament having the resiliency of polyamide and the stain resistance of polyolefin.
Still another object of the invention is provide a method for forming a carpet face filament which exhibits inherent antistatic properties.
SUMMARY OF THE INVENTION
With regard to the above and other objects, the invention provides a conjugate carpet face yarn comprising trilobal or delta cross-section polyolefin filaments, preferably polypropylene, having a denier in the range of from about 1350 to about 1550 per 84 filaments and a plurality of generally co-linear substantially smaller polyamide fibrils, preferably of nylon 6 embedded within the polyolefin filaments wherein the polyamide fibrils comprise from about 5 to about 40 wt. % of the total filament.
It has been found that the small polyamide fibrils which are preferably nylon 6, arranged in a polyolefin matrix in a principally polyolefin filament, provide in a polyolefin-type carpet yarn what amounts to nylon-type properties in terms of resiliency but without the draw backs of nylon. That is, the yarn exhibits the good anti-staining properties of polyolefins and their favorable flame retardancy and anti-static properties, but does not matt like polyolefin fibers. The yarn is also less costly to produce than nylon, since polypropylene is about 60% cheaper per pound in the current market than nylon.
In another preferred embodiment, the invention provides a method for making fiber for a carpet face yarn having the stain resistance of a polyolefin face yarn and the resiliency of a polyamide face yarn. The method comprises blending from about 5 to about 40 wt. % polyamide pellets with from about 60 to about 95 wt. % polyolefin pellets. The blend is then fed to a hot melt extruder to melt the mixture. Once melted, the molten mixture is forced at a shear rate within the range of from about 1000 to about 5000 reciprocal seconds through a spinneret containing a plurality of trilobal or delta capillary openings. The conjugate filaments thus formed contain polyamide fibrils formed in-situ in a trilobal or delta cross-section polyolefin matrix. Furthermore, the conjugate filaments have a denier ranging from about 1350 to about 1550 per 84 filaments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration, not to scale, of a preferred spinneret orifice configuration for producing the carpet filaments of the invention.
FIGS. 2 and 3 are cross-sectional illustrations, not to scale of the trilobal or delta conjugate filaments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
An important feature of the carpet face yarn of the invention is that it has the resiliency and flame retardance of polyamide yarns such as nylon 6 and nylon 66, yet has the stain resistance of polyolefin yarns such as polypropylene. Furthermore, the trilobal carpet face yarn of the invention is resistant to the formation of a static electric charge common to polyamide carpet yarns.
The polyolefins which may be used to form the carpet yarn of the invention includes polyethylene, polypropylene, poly(1-butene), poly(3-methyl-1-butene), poly(4-methyl-1-pentene), and the like as well as combinations or mixtures of two or more of the foregoing. Of the foregoing polyolefins, polypropylene is particularly preferred One suitable source of polypropylene is the polypropylene available from Shell Chemical Company under the trade name designation 5A72.
The polyamide polymers used with the invention include the condensation product of a dibasic acid and a diamine such as adipic acid and hexamethylene diamine (nylon 66), and the addition reaction products of monomers containing both an acid and an amine group in the molecule, such as the polymerization product of e-caprolactam to form polycaproamide (nylon 6). Higher analogs of nylon 6 and 66 may also be used. Of the foregoing, nylon 6 is the most preferred polyamide for use in forming the carpet face yarn of the invention. One suitable source of nylon polymer is the nylon 6 polymer available from BASF Corporation under the trade name designation Type 403.
It is preferred that the polymeric mixture used to form the carpet face yarn contain from about 60 to about 95 wt. %, preferably from about 75 to about 85 wt. % polyolefin, and from about 5 to about 40 wt. %, preferably from about 10 to about 20 wt. % polyamide.
The polyolefin and polyamide polymers are preferably dry blended prior to feeding the mixture to the extruder. In the alternative, the polymers may be fed directly to the extruder in any order provided there is sufficient residence time in the extruder to assure thorough mixing of the two polymers. It will be recognized that a preformed mixture of polyolefin and polyamine may also be fed to the extruder.
Once formed, the mixture of polyolefin and polyamide is melted and extruded using typical nylon 6 processing temperatures and procedures. Accordingly, the molten mixture is forced at a temperature within the range of 240° to about 270° C. through a spinneret containing a plurality of trilobal or delta capillary openings. FIG. 1 illustrates a capillary opening 10 for use in forming the filaments of the present invention in a trilobal configuration. The capillary opening 10 has legs 12 of equal length so that the melted mixture flows through the capillary opening 10 in legs 12 thereby increasing the shear rate on the molten mixture and causing the filament to set in a trilobal cross-sectional configuration 14 as illustrated in FIG. 2 or a delta cross-sectional configuration 16 as illustrated in FIG. 3. In FIGS. 2 and 3, the polyolefin 18 forms the bulk of the filament with fibrils 20 of polyamide dispersed within the filament, generally toward the center portions of the filament.
The shear rate of the molten mixture during extrusion is an important factor in practicing the present invention for optimal results. Shear rates in the range of from about 1000 to about 5000 reciprocal seconds are preferred. Particularly preferred is a shear rate within the range of from about 2000 to about 3000 reciprocal seconds, with a shear rate of about 2500 reciprocal seconds being most preferred. By selecting a plurality of capillary openings having a trilobal arrangement, the desired shear rate for extrusion of the mixture may be obtained.
After spinning, the conjugate filament thus formed is drawn one or more times, preferably about 3 times and then texturized with either a hot air jet or a steam jet. Unlike other polymeric materials, spinning, drawing and texturizing of the conjugate filaments in discrete batch operations is not required. Accordingly, the conjugate filaments of the invention may be spun, drawn and texturized essentially continuously without the need for a curing or a waiting period after each step. In the alternative, any two of spinning, drawing and texturizing may be done essentially continuously with a curing or waiting period after the batch step and before the continuous steps.
For purposes of obtaining colored carpet face yarns, the polymers which are combined to make the yarns of the invention may each contain pigments or chemical dyes, or the finished yarn may be dyed. Useful inorganic pigments include cadmium mercury, cadmium mercury orange, cadmium sulfide yellow, cadmiumsulfoselenide, titanium dioxide, titanium yellow, titanium green, titanium blue, cobalt aluminate, manganese blue, manganese violet, ultramarine red, ultramarine blue, ultramarine violet, chrome yellow, and the like. Organic pigments include permanent red 2B, perylene red, quinacridone red, diazo orange, diazo yellow, isoindolinone, hansa yellow, phthalocyanine green, phthalocyanine blue, quinacridone violet, doxazine violet, and the like. Chemical dyes include the mono- and disulfonated acid dyes, as well as anthraquinone, triphenylmethane, pyrazolone, azine, nitro and quinoline dyes. When used, the pigment dyes may be predispersed in the polyolefin masterbatch before the polyolefin and polyamide are extruded.
Since pure polyolefin filaments cannot generally be dyed with chemical acid or basic dyes, pigments dyes are typically used to give the polyolefin its color in a process known as "solution dyeing". Solution dyeing results in a permanent color that is highly resistant to staining or fading due to uv light. In contrast to pure polyolefin filaments, the conjugate filaments of the invention may be dyed with chemical acid or basic dyes in addition to the pigment dyes, and the dyed conjugate filaments of the invention typically have stain resistant properties similar to pure polyolefin filaments.
A particular advantage of the conjugate filaments of the invention is the synergistic flame retardancy of the filaments. Even though the filaments may contain only about 15 wt. % polyamide and no flame retardants, the conjugate filaments of the invention may have about a 75% increase in flame retardance relative to the flame retardance of pure polyolefin filaments. When desired, the polyolefin and polyamide conjugate filaments of the invention may also contain flame retardants. Flame retardants suitable for use with one or both of the polymers of the invention include brominated polystyrene, hexabromocyclododecane, octabromodiphenyl oxide, decabromodiphenoxyethane, decabromodiphenyl oxide, ethylene-bis(tetrabromophthalimide), ethylene-bis(dibromonorborane dicarboximide), pentabromodiphenyl oxide, tetradecabromodiphenoxy benzene, aluminum oxide trihydrated, antimony oxide, sodium antimonate, zinc borate, di-acrylate ester of tetrabromobisphenol-A, and the like. A preferred flame retardant system will generally contain a halogenated organic compound and a flame retardant synergist such as antimony oxide. The total amount of flame retardant in each polymer may range from about 5 to about 15 wt. % of the total weight of conjugate filament.
While not desiring to be bound by theoretical considerations, it is believed that the properties of the carpet face yarn of the invention may be due, at least in part, to the formation of in-situ polyamide fibrils in a matrix of polyolefin. The in-situ fibril formation is due to the immiscibility of the polymers with one another, and the shear forces exerted on the molten mixture in the capillary openings. Fibrils of polyamide are thereby formed near the center of the capillary openings of the spinneret where the shear forces are the least. Typically the nylon fibrils thus formed have a diameter in the range of a fraction of a micron to a few microns and a length of several tens of microns whereas the overall cross-sectional length of each side of the trilobal or delta filaments containing the fibrils may range from about 1 to about 3 millimeters.
Since the amount of polyolefin in the mixture is much greater than the amount of polyamide, the polyolefin will form a matrix encapsulating the polyamide fibrils. These polyamide fibrils provide reinforcing to the polyolefin matrix similar to reinforcing provided by a welt having a semi-rigid inner core. Accordingly, the polyamide fibrils improve the resiliency of the yarn over yarn made only with polyolefin polymer.
Another factor which may contribute to the formation of fibrils in the center of the filament is the difference in the melt viscosity of the polyolefin and polyamide phases. At a shear rate of 2500 reciprocal seconds, polypropylene has a melt viscosity of 330 poises at 260° C. at the capillary wall. The melt viscosity for the same temperature and shear rate for nylon 6 having a relative viscosity of 2.4 is 700 poises and is 1160 poises for nylon 6 having a relative viscosity of 2.7. Accordingly, the ratio of polyamide melt viscosity to polyolefin melt viscosity is typically within the range of from about 2:1 to about 3:1 for forming the conjugate filaments of the invention. The lower polyolefin viscosity will cause the polyolefin to flow much faster through the capillary opening at the walls of the opening where the shear rate is highest while the polyamide flows through the sections of the capillary opening away from the walls.
EXAMPLE
A dry blend mixture of 14 wt. % nylon 6 having a relative viscosity of 2.4 (Type 403 from BASF Corporation) and 86 wt. % polypropylene pellets having a melt index of 12 (5A72 from Shell Chemical Company) were fed from a feed hopper directly into a 2 1/2 inch hot melt extruder wherein a homogenous molten mixture was obtained. A beige polypropylene color concentrate was added to the molten mixture for color. The molten mixture was then pumped through a pack of screens to remove any particles greater than 20 microns. The screened mixture was pumped to a spinneret having a 40 trilobal capillary openings in order to form conjugate filaments. Each trilobal capillary had leg lengths of 0.0205 inches and leg widths of 0.008 inches. The extrusion rate was 0.625 pounds per hour per hole at 260° C. thereby producing a shear rate of 2450 reciprocal seconds. Carpet yarn was spun from the filaments thus formed in a two-step process. The spinning was done using nylon 6 extrusion conditions at 320 m/min. The filaments were spun at a denier of 2175 per 42 filaments (Delta) at 258° C. melt temperature to yield a spun yarn denier of 1825. The yarns were then drawn three times at 125° C. and hot air jet texturized at 130° C. The drawing was 2 ply to yield a textured, singles yarn having a denier of 1450 per 84 filaments. The relaxation ratio was 0.71:1 and the drawn denier was targeted for 1450 denier with 80 filaments. The physical properties of the two ply yarn are given in Table 1.
TABLE 1______________________________________ Denier Tenacity Elongation CrimpDescription (gms) (gpd) (%) (%)______________________________________100% SA72 1470 2.45 41 2.20100% PA6 1451 3.20 50 3.2110% PA6, 90% 1463 2.49 49 2.92SA7215% PA6, 85% 1490 2.61 45 3.15SA72______________________________________
The 1450 denier filaments were in turn also two-ply twisted and heat set. The twisting was 4.50×4.50 tpi and the heat set was done on a Superba Stuffer Box at a tunnel temperature of 135° C. To form a carpet from the yarn of the invention the filaments may be broadloom tufted in 34 ounce cut pile (54 stitches, 15/32 inch pile height). Carpet thus formed will have a Carpet Research Institute (CRI) floor rating above about 2 and generally from about 2 to about 3 whereas pure nylon carpet has a CRI floor rating of about 2.5 and pure polypropylene carpet has a CRI floor rating of about 1.8.
The carpet face yarn of the invention also exhbits a flame retardancy as determined by a Radiant Panel test in the range of from about 0.3 to about 0.4 watts/cm 2 whereas pure nylon yarn has a flammability rating of about 0.5 to 0.6 watts/cm 2 and pure polypropylene yarn has a flammability rating of about 0.2 to about 0.25 watts/cm 2 . The apparent increase in flame retardancy appears to be a synergistic increase since the filaments contain at most about 15 wt. % nylon 6.
As compared to polypropylene without nylon reinforcement, the conjugate carpet yarn containing nylon fibrils has an increase in tensile strength, and fiber shrinkage. Accordingly, the 10% and 15% PA6 conjugate filaments are better than 100% polypropylene (SA72) in terms of flame retardance and resiliency and the 15% PA6 conjugate filament rate comparable to the 100% PA6 sample in terms of flame retardance and resiliency.
While it is preferred to utilize polyolefin and polyamide polymers without additives other than flame retardants and dyes or pigments, it will be recognized that the individual polymers which are combined to form the carpet face yarn of the invention may contain any one or more additives selected from antioxidants, fillers, antistatic agents, melt processing aids, uv and thermal stabilizers, plasticizers, and the like.
Stabilizers useful with the polymers used to form the conjugate filaments of the invention include calcium powders, calcium stearate, phenols and hindered phenols, zinc oxide, and the like.
Antioxidants may be selected from alkylated phenols and bisphenols, alkylidene-bisphenols, alkylidene-trisphenols, alkylidene polyphenols, thiophenols, dithio-bisphenols, dithio-trisphenols, thio-polyalkylated phenols, phenol condensation products, amines, dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, ditridecyl thiodipropionate, pentaerythritol tetrakis(β-lauryl thiopropionate), p-benzoquinone, 2,5-ditert-butylhydroquinone, and the like.
Having described the invention and its preferred embodiments, it will be recognized that the variations of the invention are within the spirit and scope of the appended claims.
|
The specification describes a conjugate carpet face yarn including trilobal or delta cross-section polyolefin filaments and a plurality of generally co-linear smaller polyamide fibrils embedded within the polyolefin filaments. This yarn has the stain resistant properties of polyolefin based yarns and the resiliency of polyamide based yarns.
| 3
|
[0001] This application is a continuation of U.S. patent application Ser. No. 10/856,534, filed May 28, 2004, which claims the filing date benefit of U.S. Provisional Application No. 60/474,836, filed May 30, 2003, and also claims the filing date benefit of U.S. Provisional Application No. 60/475,210, filed Jun. 2, 2003.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a new improved input planetary stage for a large gear box. The input planetary stage cited in this invention is for a wind turbine power generator having an output power capacity rating of 500 kW and greater.
[0003] Wind turbine power generators are considered one of the most cost effective and environmentally friendly methods of generating electricity. Individual wind turbines are currently being designed and built for electrical power generation in excess of 5 MW. A key component of most wind turbines are their gearboxes, which are subjected to varying high loading at low speeds, and have design lifetimes of 20 years. Anything that will give these gearboxes more durability and efficiency is highly coveted by wind turbine manufacturers and operators.
[0004] Modern large wind turbine generators (500 kW and greater) are massive devices commonly using large planetary gear systems as the input stage. These heavy gearboxes, which are mounted atop high towers, often located in remote locations such as on a mountain or offshore, experience severe fluctuations in wind conditions and temperature and are often exposed to a corrosive seawater environment and/or abrasive particulates. A gearbox failure can require removing the gearbox using mammoth equipment, and rebuilding it back at the manufacturer's facility followed by reinstallation at the remote location. The concurrent loss of electrical generation is also a costly event unto itself.
[0005] Manufacturers recognize that removing the peak asperities from the contact surfaces of gear teeth prior to full field operation increases the service life of the gearbox. There are two obvious advantages to removing peak asperities. Firstly, this will reduce the amount of metal-to-metal contact which produces lubricant debris and which is known to be destructive to gears and bearings. Secondly, it improves the material ratio (R mr ), which is a measure of the amount of gear tooth surface available for supporting the load. The industry assumed that any technique to remove the peak asperities was equivalent as long as no obvious metallurgical damage or no significant alteration to the lead and profile geometry occurred. Gear honing, for example, is often used in the aerospace industry to reduce peak asperity heights. Honing could have been a consideration for wind turbine gearboxes; except that it is cost prohibitive on such large gears as most honing equipment is limited to processing gears having a diameter of 12 inches or less. As such, today's wind turbine gears typically have ground teeth flanks and are recommended to be operated through a run-in procedure to remove the peak asperities from the contact surfaces.
[0006] It has been taught for a number of years that optimum performance benefits for bearings are achieved when the mating contacting surfaces are both isotropically superfinished to an arithmetic average roughness (R a ) of less than approximately 0.075 micron using chemically accelerated vibratory finishing.
[0007] Similarly, gears in auto racing transmissions, which operate under high loads with high pitch line velocities, have benefited from this isotropic superfinishing process with teeth finishes of Ra from 0.3 micron to less than 0.025 micron. Such superfinished gears experience reduced contact fatigue, operating temperature, friction, noise and vibration.
[0008] Superfinishing enables the development of hydrodynamic lubrication (HL) or elastohydrodynamic lubrication (EHL). HL exists when there is complete separation of the mating gear teeth during operation achieved by a continuous lubricant film. EHL exists in highly loaded mated gear teeth under operation when the separating fluid film formation is influenced by elastic deformation of the contacting surfaces. Hence, with HL or EHL during their high speed and high load operation, superfinished auto racing transmissions experience almost no metal-to-metal contact of the mating teeth.
[0009] In sharp contrast to auto racing transmissions, the input planetary stage gears used in the wind turbine power generating industry operate under significantly different conditions. In wind turbine applications, the gears experience very high, varying loads at low pitch line velocities such that boundary lubrication rather than hydrodynamic (HL) or elastohydrodynamic lubrication (EHL) is predicted. Boundary lubrication exists when the mating gear teeth during operation are wetted with fluid but the lubricant film thickness is less than the combined mating surface roughness. Thus, the lubricant film can be penetrated by peak asperities, and metal-to-metal contact generates metal debris from the gear teeth. Traditionally manufactured ground wind turbine gear teeth (see “Standard for Design and Specification of Gear Boxes for Wind Turbines,” ANSI/AGMA/AWEA 6006-A03) after the run-in process described below, are hoped to achieve a surface finish of Ra=0.5-0.7 micron. However, those practiced in the art recognize that a traditionally manufactured hollow wheel will have a much higher surface finish. It is recommended by the AGMA standard that this gear's finish not exceed Ra>1.6 micron. Finishes of 0.5-0.7 micron are considered sufficient to avoid most metal to metal flank contact. It was also believed that this surface condition would result in significant lubricant retention needed with the slow moving gear teeth and thus the best possible lubrication condition would be achieved. However, a major source of wind turbine gear box failure is failure of the bearings. Even with run-in achieving the above finishes, metal to metal teeth contact continues on the planetary gear stage teeth and produces lubricant debris, which in turn contributes to the rapid bearing failures.
[0010] In contrast, chemically accelerated vibratory superfinishing to a condition of Ra<0.3 micron was thought to be too smooth for large wind turbine generators in that the teeth flanks would have insufficient lubricant retention for operation and tooth failure was predicted. Thus, it was questionable whether or not superfinishing using chemically accelerated vibratory finishing of the input planetary stage would add any performance value to the gear box. Only lengthy and costly field testing could provide the answer.
[0011] In addition, it was thought by those skilled-in-the-art that the large, heavy gears that make up an input planetary stage of a large wind turbine generator could not be processed in vibratory finishing equipment used in the chemically accelerated vibratory finishing process. This vibratory finishing equipment is either in a bowl or tub form. The input planetary stage gears are typically 200 kg or more for generators of an output capacity of 500 kW and larger. This gear weight was thought to be beyond the normal range of operation for vibratory finishing equipment.
[0012] In particular, it was thought that a large hollow wheel gear (annulus gear) weighing from 400 kg to greater than 5000 kg could not be superfinished in a large vibratory bowl. A person skilled-in-the-art would have predicted that such a massive gear with its relatively small cross sectional area would have immediately sunk to the bottom of the bowl damaging the lining, the gear or both. In addition, the heavy gear would have been expected to fracture significant quantities of the ceramic media used in the vibratory finishing equipment because of the high pressure exerted upon the media. The shards produced by the crushing of the ceramic media would have sharp points and edges. Instead of smoothing the critical contact surfaces of the gear teeth to a superfinished condition, these media fragments would have been predicted to damage these surfaces resulting in roughened, gouged and even denting the surfaces, especially nearer the bottom of the bowl where the pressure is greatest. The damage would have been significantly augmented for softer through-hardened (32-40 HRC) hollow wheel gears. The anticipated high rate of media attrition from fracturing would also add an unacceptable processing cost as well as causing the problem of clogging and blocking the drains of the processing machine.
[0013] Additionally, in processing the hollow wheel, it would have been expected that there would have been a variance in the intensity of media pressure across the lead of the gear teeth. The pressure of the media on the gear teeth nearer the bottom of the bowl is greater than the pressure of the media near the top. As a result, more stock would be expected to be removed from the gear teeth nearer the bottom than nearer the top. Therefore, the vibratory processed hollow wheel gear could end up being out of dimensional tolerance. This could be partially mitigated by removing the gear half way through the process, turning it over, returning it to the bowl, and continuing the process. It should be mentioned though that turning such a large gear is time consuming and potentially dangerous. Also, part of the center width of the gear teeth would be processed for twice the finishing time, possibly causing a resultant change in the tooth geometry. Each of the above predicted shortcomings would have been predicted to make this superfinishing process for large hollow wheel gears commercially impractical and unpredictable.
[0014] Similar shortcomings would have been expected for the chemically accelerated vibratory finishing of the other gears that make up the input planetary stage of a wind turbine gear box. These gears, known as planets and sun pinions, are similarly massive, typically weighing in excess of 200 kg each. As such, those skilled-in-the-art would have predicted they could not be processed in vibratory finishing equipment, whether bowls or tubs. Therefore, the wind turbine industry could not realize the benefits of this superfinishing process for the input planetary stage of the gear box.
[0015] It should be noted that it is desirous to be able to use through-hardened hollow wheel gears instead of gas nitrided or gas carburized hollow wheels in the large input planetary gear stage. Through-hardened hollow wheels are less costly to manufacture.
[0016] Gas nitriding is expensive, time consuming, and produces a very hard, brittle “white layer” on the teeth surfaces. Those practiced in the art recognize this white layer must be removed prior to use of the gear. However, removal of the white layer by grinding is at great expense and risk to ruining the hollow wheel. Alternative removal of the white layer by chemical dissolution is a very hazardous and environmentally unfriendly process.
[0017] In gas carburizing, due to the significant distortion from the heat treatment process, final grinding of the teeth is required, which is also an expensive process. Furthermore, after final grinding, the gas carburized hollow wheel requires temper burn inspection, another hazardous and environmentally unfriendly process.
[0018] Additionally, through-hardened hollow wheels are not just less expensive to manufacture, they can also be more geometrically accurate when compared to nitrided or carburized hollow wheels. This is very beneficial in that the remaining gears of the planetary gear set are routinely manufactured to high geometrical accuracy. Thus, if a more accurate, less expensive through-hardened hollow wheel can be operated with high accuracy planet and sun gears, the resulting planetary gear set could be highly efficient and of sufficient durability. If the through-hardened hollow wheel could be superfinished using chemically accelerated vibratory finishing, its teeth would be of sufficient surface capacity and capable of operating in HL or EHL regimes, thereby reducing debris generation. Thus, if superfinished through-hardened hollow wheels combined with superfinished planets and sun gears can operate satisfactorily at wind turbine designed loads and speeds, the result would be a superior input planetary gear stage. Alternatively, if the planets and sun pinion gears could be superfinished and mated to a non-superfinished hollow wheel, irrespective of its metallurgical heat treatment, the result would be an improved input planetary gear stage for a wind turbine generator of output capacity of 500 kW and greater. Therefore, superfinishing some, or preferably all, of the gears in the input planetary stage will result in a reduction or elimination of lubricant debris generated from the gear teeth, thereby reducing or eliminating a source of damage to the bearings.
[0019] In point of fact, gearbox manufacturers for large wind turbine power generators had only one viable choice for reducing peak asperities after grinding, and that was the run-in process. In the run-in process, the gears are smoothed in the assembled state by operating the gears box under various loads and speeds such that the contact area peak asperities shear away or plastic deform themselves. It should be mentioned that this was also the most economical route to take as the gearbox has to be tested and certified under load conditions anyway prior to its shipment and installation at its final destination. The run-in and testing phase can be conducted simultaneously on the same test rig. The AGMA/AWEA & The Danish Energy Agency, for example, have written guidelines for designing wind turbine gearboxes and stress the need for run-in. The impact of surface finish on gear tooth durability is briefly discussed, but the methodology of smoothing the surface is given no consideration. This view, that the method of removing the peak asperities is irrelevant, is generally shared by this industry as well as other gear manufacturers.
[0020] An ideal run-in process requires operation of the gearbox at different loads and speeds to simulate actual field conditions in order to smooth the asperity peaks across the whole load-carrying surface. However, duplicating actual service conditions on a test rig is not only virtually impossible, but is also impractical as well due to equipment, time and cost constraints. During the run-in process, the oil film thickness is often purposefully reduced to allow more asperity peak contact thereby resulting in a smoother surface. Once the run-in process is completed, the gearbox run-in lubricant and filtration system should be serviced. Typically the lubricant is drained, the gearbox flushed, and replaced with fresh lubricant, and the filter, which captures metal debris generated during the run-in process, is cleaned or replaced. Unfortunately, even during run-in, this metal debris can initiate serious damage to the bearings and gear contact surfaces before collection in a filter. And, most filters are capable of capturing only the largest debris particles and allow passage of the finer particles. These fine particles still are capable of causing surface damage, particularly to the gear box bearings.
[0021] Also, no matter how thoroughly or carefully the run-in procedure is conducted, this process leaves microscopic material distress (stress raisers) on the gear teeth contact regions due to the high stresses created to mechanically shear, fracture or elastically deform the peak asperities. These stress raisers act as initiation sites for future contact fatigue failures or micropitting.
[0022] Consequently, even after run-in, the input planetary gears often experience micropitting during the early period of field service. Micropitting by itself is another source of metal debris which can cause further damage to the bearings and gear contact surfaces since the metal debris is not immediately or completely trapped by the filtration system. It should be stressed that even microscopic metal debris particles, which can pass through a 10-micron filter, are still large enough to initiate damage. Micropitting is acknowledged to be an indicator of possible future gear failure and/or serious wear problems. Whenever severe wear occurs, the gear tooth profile is changed leading to increased vibration and noise which places an elevated stress on the gear box system.
[0023] Additionally, run-in procedures typically only smooth the drive side of the hollow wheel and sun gear while leaving the coast sides of these gear teeth as machined. During adverse operating conditions such as strong gusts of wind or turbine braking, coast side loading can be high enough to produce asperity contact and contribute to harmful metal debris. However, chemically accelerated vibratory superfinished gears are smoothed on both sides of the contact teeth surfaces.
[0024] Again, it needs to be emphasized that the industry has failed to give guidance on the actual optimum surface finish, or on the method of generating such optimum surfaces to improve gearbox durability. Instead it has relied mainly on run-in procedures to smooth the gear teeth contact areas to what was believed to be a satisfactory condition.
SUMMARY OF THE INVENTION
[0025] Disclosed herein is an improved large planetary gear system used on the input stage of wind turbine power generators. This improved planetary gear system reduces or eliminates lubricant debris traditionally generated from the gear teeth, thereby eliminating an initiating source for bearing failure. To achieve these results, some and preferably all of the gear teeth within the planetary gear system are superfinished using chemically accelerated vibratory finishing to a surface roughness of approximately 0.25 micron or less.
[0026] In particular, a novel method is disclosed for superfinishing the massive hollow wheel gear, especially a through-hardened hollow wheel gear, placed horizontally in a vibratory bowl.
[0027] It will be appreciated that the inventive teachings disclosed herein are useful to all other applications of large planetary gear sets. Similarly, the teachings of this invention are applicable to some or all the gears of other large, non-planetary, gear box types where boundary lubrication regimes exist due to traditionally ground teeth finishes. The style of gears within these gear boxes, such as spur, helical, face, bevel and the like, are not important to the inventive concept disclosed herein.
[0028] It will be readily apparent to those skilled in this art that various modifications and changes of an obvious nature may be made, and all such modifications and changes are considered to fall within the scope of the claims. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. Examples are superfinishing all the gears, and/or all the bearings within these types of large gear boxes. Hence, the specific embodiments described are not intended to be limiting but merely illustrative of the inventive method.
[0029] The unique and significant feature of the process used in the present invention is the surface leveling mechanism utilized to achieve the surface finish. A chemical solution is used in the vibratory bowl or tub in conjunction with ceramic media. When introduced into the machine, this chemical solution reacts with the metal and produces a stable, soft conversion coating across the asperities (peaks and valleys) of the gear teeth. The rubbing motion across the flanks of the gear teeth developed by the machine and media effectively rubs the conversion coating off the “peaks” of the surfaces, but leaves the “valleys” untouched. The conversion coating is continually re-formed and rubbed off during this stage producing a surface leveling mechanism. This mechanism is continued in the vibratory machine until the desired surface finish is attained. At this point, the active chemistry is turned off and is typically rinsed from the machine with a burnish solution, which does not react with the basis metal. During this stage, the conversion coating is rubbed off the gear teeth flanks one final time to produce the finished gears for the input planetary gear stage. And finally, since the process is water based, approximately room temperature and open atmosphere, there is no chance of tempering of the gear with chemically accelerated vibratory finishing. Thus, temper burn inspection is not required after superfinishing with the present invention.
[0030] Since the asperity peaks are removed prior to installation, no micro-stresses are introduced such as in the conventional run-in smoothing procedure. In fact, the need for run-in is greatly reduced or completely eliminated. Thus the problems of micropitting and fretting of the gear surfaces are reduced or eliminated. Also, the gears finished with the present invention generate no significant metal debris at start-up or after being in service for long periods, and thus avoids metal debris damaging the bearings. This also allows for longer time between lubrication servicing. Since the smoothing of the surfaces also reduces friction, the gears do not contribute to the typical break-in temperature spike responsible for a reduced life of the lubricant, bearings and seals. Noise and vibration can also be expected to be reduced for two reasons. Firstly, a reduction of friction will effect reduced vibration and noise. Secondly, a reduction in wear means that the transmission error will stay more constant with time, and therefore the noise also will not increase.
[0031] Prior to this invention, attempts to improve the durability of wind turbine power generator gearboxes was achieved by surface grinding the gear teeth followed by run-in, whereby the gearbox was operated under varying loads and speeds. Run-in can remove the peak asperities from some of the gear tooth mating surfaces, but also has a number of serious deficiencies as discussed above when compared to the present invention. Accordingly, several objects and advantages of the present invention over the teeth grinding and run-in process applicable to wind turbine power generators having an individual output power capacity of 500 kW and greater are:
1. to provide an improved input planetary stage having the entire teeth flanks superfinished, which reduces or eliminates damaging metal debris generated by the gears during run-in or during actual service; 2. to provide an improved planetary stage with significantly reduced or eliminated metal debris normally generated from the gear teeth, thereby reducing or eliminating an initiating source for bearing failure; 3. to provide a practical and cost-effective method of superfinishing the large hollow wheel gears, especially high geometrical accuracy through-hardened hollow wheels, using chemically accelerated vibratory finishing to a superior surface having a lower R a , an increased R mr , and a significant reduction of stress raisers; 4. to provide an improved input planetary stage since now some and preferably all of the gear flanks of any style gear 200 kg and larger can be superfinished to an R a of 0.25 micron or less while maintaining dimensional tolerances; 5. to provide an improved input planetary stage with significantly reduced micropitting and fretting, which can lead to future macropitting, wear and ultimately to failure of the teeth and bearings; 6. to provide a method which simultaneously superfinishes the drive and coast sides of all the gears and particularly the hollow wheel and sun gear teeth again reducing or eliminating the potential for harmful metal debris; 7. to provide an improved input planetary stage with a significantly reduced temperature spike which can be damaging to the metallurgy, lubricant and seals during the run in or early field operation; 8. to provide an improved input planetary stage with a significantly reduced vibration and/or noise caused by friction and/or tooth profile changes due to wear; 9. to provide an improved input planetary stage having gears with an increased material ratio (R mr ) on the contact teeth surfaces allowing for a greater power density; 10. to provide an improved input planetary stage allowing streamlining or elimination of the run-in process; 11. to provide a process that does not require temper burn inspection after the gears are superfinished; 12. to provide a chemically accelerated vibratory finishing process applicable to all style gears of 200 kg and greater in all types of gear boxes that operate in a boundary lubrication regimes such that superfinishing reduces or eliminates lubricant debris; and 13. to provide an improved large gearbox where some, or preferably, all the gears and/or bearings are superfinished to reduce or eliminate lubricant debris.
[0045] Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a drawing of the cross section of a planetary gearbox with three planet gears.
[0047] FIG. 2 a is a drawing of a gear tooth illustrating the tooth contact area.
[0048] FIG. 2 b is a drawing of the cross section of two gear teeth.
[0049] FIG. 3 is a drawing of the vibratory bowl containing media used to superfinish the hollow wheel gear;
[0050] FIG. 4 is a drawing of the vibratory bowl illustrating the ideal position for the hollow wheel gear during the superfinishing process.
[0051] FIG. 5 is a drawing illustrating the location at which the chemical solutions are delivered during the superfinishing process.
[0052] FIG. 6 are the surface parameters and profile measured on a typical machined/ground flank of a hollow wheel gear tooth.
[0053] FIG. 7 are the surface parameters and profile measured on a typical superfinished flank of a hollow wheel gear tooth using the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0054] FIG. 1 is a drawing of an input planetary stage typically used in wind turbine gearboxes. It consists of a hollow wheel gear ( 1 ), two or more planet gears ( 2 ), and a sun gear ( 3 ). The teeth ( 4 ) of each gear are to be superfinished. FIG. 2 a is a 3-dimensional view of a single gear tooth ( 4 ) and FIG. 2 b shows a 2-dimensional cross section of two gear teeth ( 4 ). The gear tooth ( 4 ) consists of the flank ( 5 ), which is the working or contacting side of the gear tooth, the top land ( 6 ), which is the top surface of the gear tooth, the bottom land ( 7 ), which is the surface at the bottom of the space between adjacent teeth, and the root fillet ( 8 ), which is the rounded portion at the base of the gear tooth between the tooth flank ( 5 ) and the bottom land ( 7 ). The most critical area 11 is the tooth contact pattern ( 9 ), which is the surface area of a gear tooth which has been in contact with its mate when the gears are in operation. In the present invention, one or more of the planetary gears of a wind turbine gearbox including the sun ( 3 ), the planets ( 2 ) and the hollow wheel gear ( 1 ) are superfinished on their drive and coast sides using chemically accelerated finishing in a vibratory bowl or tub to an R a of 0.25 micron or less.
[0055] General Description of Superfinishing Process
[0056] A general description of the superfinishing process follow with commonly owned U.S. Pat. Nos. 4,491,500 and 4,818,333, and U.S. patent application Ser. Nos. 10/071,533, 09/758,067, and 10/684,073, each of which is incorporated herein by reference. An active chemistry is introduced into the vibratory finishing apparatus that is capable of converting the metal of the gear to a composition of a reduced hardness film that is physically and chemically stable and may or may not be visually perceptible. This film is known as a conversion coating. When this film is developed on the surface of the gear, the action of the media elements upon the gear will only remove the film from the asperity peaks of the gear, leaving the depressed areas of the coating intact. By constantly wetting the metal surface with the active chemistry, the stable coating will continuously re-form, covering those areas where the bare underlying metal has been freshly exposed, to provide a new layer of the relatively soft film. If that portion remains higher than the adjacent areas it will continue to be rubbed away until any roughness has been virtually eliminated.
[0057] The amount of active chemistry solution utilized will be only that which will maintain all surfaces of the treated parts in a wetted condition, so as to ensure continuous and virtually instantaneous re-formation of any coating removed through the rubbing action. As will be evident to those skilled-in-the-art, the amount of any media utilized will depend upon numerous factors, such as the surface character, area, weight and composition of the gears being treated, the composition of the solution utilized for the conversion coating, temperatures of operation, the degree and rate of refinement to be achieved, etc.
[0058] Although the properties exhibited by the conversion coating produced on the gear are of crucial importance to the successful practice of the present process, the formulation of the active chemistry utilized to produce the coating is not. The composition must be capable of quickly and effectively producing, under the conditions of operation, relatively soft reaction products of the basis metal and the coating must be substantially insoluble in the liquid medium so as to ensure that removal occurs primarily by rubbing, rather than by dissolution. The active chemistry will generally consist of water and up to about 40 weight percent of active ingredients, comprised essentially the conversion chemicals but also optionally and desirably including an oxidizing agent, and in some instances a stabilizer and/or a wetting agent. After the desired amount of refinement is attained, the active chemistry is shut off. Thereafter, a burnishing solution may be introduced into the vibratory machine. The burnishing solution, which is non-reactive to the basis metal, serves to remove the conversion coating from the surface to create a specular appearance.
[0059] Superfinishing the Planets and Sun Gears
[0060] In one embodiment of the present invention, the sun gear and planet gears can be superfinished in a suitably sized vibratory bowl or tub machines. Multiple gears with suitable mounting can be superfinished simultaneously. A device may be used to support the gear(s) or to keep the gear(s) from contacting the sides of the vibratory bowl or tub while in operation. The gear(s) are rapidly agitated to produce relative movement among the gear(s) and the non-abrasive ceramic media. The surfaces of the gear(s) and the media are maintained in a wetted condition with an aqueous solution of FERROMIL® FML-590 at 30 v/v %. The non-abrasive solid media elements are of an amount, size and shape such that, under the conditions of agitation, produce uniform media rubbing of the gear teeth. The process is continued until the arithmetic average roughness (R a ) value is 0.25 micron or less. The gear(s) are then burnished to remove the conversion coating using an aqueous solution of 1.5 v/v % of FERROMIL® FBC-295 to a specular appearance.
[0061] While the preferred embodiment contemplates the use of non-abrasive ceramic media, other ceramic media, plastic media, steel media, stainless steel media and combinations of different types of media, can also be used, depending upon the physical circumstances surrounding the finishing of the gear. It is within the skill of one in the art to determine which media, or combination of media, to use in each instance.
[0062] Superfinishing the Hollow Wheel Gear
[0063] This example teaches one embodiment for superfinishing a large hollow wheel gear ( 1 ) suitable for commercial wind turbine gearboxes of output power capacity of 500 kW and greater. The hollow wheel gear ( 1 ) has the following approximate weight and dimensions. It weighs 1,620 kg, has an outer diameter of 171 cm, an inner diameter of 146 cm, and a face width of 38.5 cm. The hollow wheel can be heat treated via gas carburization, gas nitriding, or it can be through hardening. In FIG. 3 , a vibratory bowl ( 10 ) is filled to approximately two-thirds of its volume with a mixture of abrasive and non-abrasive ceramic media ( 11 ). The media size and shapes are selected such that a homogenous mixture of media has uniform contact across the gear tooth flank. The amount of media is also chosen to give the preferred amount of lifting action during processing such that the gear does not contact the bottom or sides of the vibratory bowl channel, or such that the top of the gear does not climb above the working media level. The motor weights are set to a lead angle of approximately 85 degrees.
[0064] The hollow wheel gear ( 1 ) is laid horizontally over the center hub ( 12 ) of the vibratory bowl ( 10 ) onto the stationary media mass ( 11 ) taking reasonable care to center the hollow wheel gear relative to the center of the bowl. As illustrated in FIG. 5 an aqueous solution of FERROMIL® FBC-295 at 1.5 v/v % with a flow rate of 20 L/hr is delivered into the region between the outside wall of the bowl and the outer surface of the gear ( 13 ) to reduce the effects of frictional heat generation. An aqueous solution of active chemistry consisting of FERROMIL® FML-590 at 30 v/v % is delivered at 18 L/hr into the region between the center hub ( 12 ) and the internal gear teeth ( 14 ).
[0065] The vibratory bowl ( 10 ) is started at a low frequency and is gradually increased to approximately 46 to 48 hertz whereby the hollow wheel gear settles into the media ( 11 ). The ideal position is shown in FIG. 4 where the uppermost part of the gear ( 1 ) is at or just below the media ( 11 ) and air interface. If the vibratory bowl amplitude is not between 1.5 to 2.0 mm, adjustments should be made to the lower weight to attain this amplitude. This measurement is read from an amplitude gauge mounted on the outside of the bowl ( 10 ). The hollow wheel gear ( 1 ) will remain centered during the remainder of the processing and will slowly rotate around the center hub of the vibratory bowl. (12).
[0066] The following parameters may be adjusted as needed in order to keep the gear ( 1 ) at or just below the upper surface of the media ( 11 ) so that it rotates uniformly around the center hub ( 12 ) of the vibratory bowl ( 10 ):
[0067] Media size, shape, composition and percentage of each.
[0068] Media level.
[0069] Frequency of the motor.
[0070] Amplitude and lead angle generated by the adjustable weight system.
[0071] Concentrations and flow rates of active chemistry and burnish solutions.
[0000] The adjustment of these parameters is within the knowledge of one of ordinary skill of the art.
[0072] The process is continued until the arithmetic average roughness (R a ) value of 0.25 micron or less. The flow of active chemistry is shut off, and a burnishing compound consisting of an aqueous solution of FERROMIL® FBC-295 at 1.5 v/v % is delivered at 150 L/hr into the region between the center column of the bowl and the teeth of the gear ( 15 ). The process is continued until the conversion coating is removed producing a clean and bright appearance.
[0073] The unanticipated results that were obtained were:
1. The gear remains centered in the bowl, and is suspended off the bottom of the bowl by the motion of the media, and the uppermost part of the gear remains at or just below the media/air interface. 2. The gear is superfinished with no damage from the media or media shards. 3. An R a 0.25 micron or less is achieved, and the material ratio is significantly increased.
a. FIG. 6 shows a typical surface roughness profile of the gear teeth contact area prior to superfinishing. The R a is 0.78 micron, and the R mr is 49.4%. b. FIG. 7 shows the surface roughness profile of the gear teeth contact area after superfinishing. The R a is 0.16 micron, and the R mr is 73.2%
4. The surface finish is uniform, within tolerances, across the lead and profile. 5. Only an insignificant amount, if any, of media is fractured by the process (i.e., the media attrition was extremely low).
[0081] Planetary Testing in the Field
[0082] Two wind turbine generator gearboxes having an output power capacity of greater than 500 kW had all of the gears from the input planetary stage superfinished to a surface roughness of 0.25 micron or less using the process described in the present invention. Prior to superfinishing, the hollow wheels were through-hardened, and the planets and sun gears were gas carburized. After being placed in service, the gearboxes were inspected after approximately 6 months and after approximately one year of operation. No micropitting or fretting was observed on the gear teeth surfaces. Similarly, no bearing damage was found. In comparison, ground gears smoothed only by the run-in technique commonly can start to show signs of micropitting or fretting after only 6 months of operation, and bearings begin to show damage via direct inspection or by noise/vibration monitoring. Further anticipated advantages of the present invention include reduced metal debris, improved bearing life, reduced wear, reduced vibration and noise, improved contact fatigue resistance, improved lubrication, increased time between lubricant servicing, a simplified or eliminated run-in process, and enhanced durability, efficiency, and reduced manufacturing and operating cost of the planetary gearbox.
[0083] While the apparatuses and methods of the present invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to what has been described herein without departing from the concept and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope and concept of the invention, in particular the applicability of this process to finishing any type gear, any type of large planetary gear system, not just those involved in the wind turbine industry and any type of large gear box having individual gears greater than 200 kg that operate in boundary lubrication regimes. Such examples of other industries in which this technology will be useful is in the marine propulsion and earth moving industries, the mining industries, as well as any other industry employing the use of large gear systems.
|
Disclosed herein is a new improved large planetary gear system used on the input stage of wind turbine power generators. This improved planetary gear system reduces or eliminates lubricant debris traditionally generated from the gear teeth, thereby eliminating an initiating source for bearing failure. To achieve these results, some and preferably all of the gear teeth within the planetary gear system are superfinished using chemically accelerated vibratory finishing to a surface roughness of approximately 0.25 micron or less. Several objects and advantages of the invention are to provide a gearbox with reduced metal debris, improved bearing life, reduced wear, reduced vibro-frictional noise, improved contact fatigue, improved fretting resistance, improved lubrication, to simplify the run-in process, and to enhance the durability and efficiency of the gearbox.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/696,468, filed Jan. 29, 2010, which is a continuation of U.S. patent application Ser. No. 11/110,733, filed Apr. 21, 2005, issued as U.S. Pat. No. 7,658,686, the entire disclosure of each of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a golf club, and, more particularly, the present invention relates to a large wood-type golf club head with a concave insert.
[0004] 2. Description of the Related Art
[0005] Golf club heads come in many different forms and makes, such as wood- or metal-type (including drivers and fairway woods), iron-type (including wedge-type club heads), utility- or specialty-type, and putter-type. Each of these styles has a prescribed function and make-up. The present invention primarily relates to hollow golf club heads, such as wood-type and utility-type (generally referred to herein as wood-type golf clubs).
[0006] Wood-type type golf club heads generally include a front or striking face, a crown, a sole, and an arcuate skirt including a heel, a toe, and a back. The crown and skirt are sometimes referred to as a “shell.” The front face interfaces with and strikes the golf ball. A plurality of grooves, sometimes referred to as “score lines,” may be provided on the face to assist in imparting spin to the ball. The crown is generally configured to have a particular look to the golfer and to provide structural rigidity for the striking face. The sole of the golf club contacts and interacts with the ground during the swing.
[0007] The design and manufacture of wood-type golf clubs requires careful attention to club head construction. Among the many factors that must be considered are material selection, material treatment, structural integrity, and overall geometrical design. Exemplary geometrical design considerations include loft, lie, face angle, horizontal face bulge, vertical face roll, face size, sole curvature, center of gravity, and overall head weight. The interior design of the club head may be tailored to achieve particular characteristics, such as by including hosel or shaft attachment means, perimeter weighting on the face or body of the club head, and fillers within hollow club heads. Club heads typically are formed from stainless steel, aluminum, or titanium, and are cast, stamped as by forming sheet metal with pressure, forged, or formed by a combination of any two or more of these processes. The club heads may be formed from multiple pieces that are welded or otherwise joined together to form a hollow head, as is often the case of club heads designed with inserts, such as sole plates or crown plates. The multi-piece constructions facilitate access to the cavity formed within the club head, thereby permitting the attachment of various other components to the head such as internal weights and the club shaft. The cavity may remain empty, or may be partially or completely filled, such as with foam. An adhesive may be injected into the club head to provide the correct swing weight and to collect and retain any debris that may be in the club head. In addition, due to difficulties in manufacturing one-piece club heads to high dimensional tolerances, the use of multi-piece constructions allows the manufacture of a club head to a tight set of standards.
[0008] It is known to make wood-type golf clubs out of metallic materials. These clubs were originally manufactured primarily by casting durable metals such as stainless steel, aluminum, beryllium copper, etc. into a unitary structure comprising a metal body, face, and hosel. As technology progressed, it became more desirable to increase the performance of the face of the club, usually by using a titanium material.
[0009] With a high percentage of amateur golfers constantly searching for more distance on their shots, particularly their drives, the golf industry has responded by providing golf clubs specifically designed with distance in mind. The head sizes of wood-type golf clubs have increased, allowing the club to possess a higher moment of inertia, which translates to a greater ability to resist twisting on off-center hits.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a large wood-type golf club head with a concave insert. The club head is formed of a plurality of body members that define an interior volume. A first body member is made of a metallic material and includes a sale portion and a face portion. A second body portion is made of a light weight material, such as plastic, composite, or a very thin sheet of low density metallic material. The second body portion makes up at least a portion of the club head skirt, and includes one or more concave indentations that extend into the interior volume of the club head. These indentations provide structural integrity to the second body portions, which may be very thin panels.
[0011] The second body member optionally may also include one or more convex bulges that generally extend away from the interior volume. Inserts, such as weight inserts, may be positioned within the convex bulges. Careful positioning of the weight inserts allows the designer to enhance the playing characteristics of the golf club and tailor the club for a specific swing type. The first body member may form a large portion of the club head sole, and the second body member may form a large portion of the club head crown. This weight positioning further enhances the playing characteristics of the golf club.
DESCRIPTION OF THE DRAWINGS
[0012] The present invention is described with reference to the accompanying drawings, in which like reference characters reference like elements, and wherein:
[0013] FIG. 1 shows a golf club head of the present invention;
[0014] FIG. 2 shows a body member of the golf club head of FIG. 1 ;
[0015] FIG. 3 shows a second club head of the present invention; and
[0016] FIG. 4 shows a bottom view of the club head of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0017] Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moments of inertias, center of gravity locations, loft and draft angles, and others in the following portion of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[0018] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.
[0019] FIG. 1 shows a golf club head 1 of the present invention. The club head 1 includes a body 10 having a strike face 11 , a sole 12 , a crown 13 , a skirt 14 , and a hosel 15 . The body 10 defines a hollow, interior volume 16 . Foam or other material may partially or completely fill the interior volume 16 . Weights may optionally be included within the interior volume 16 . The face 11 maybe provided with grooves or score lines therein of varying design. The club head 1 has a toe T and a heel H.
[0020] The club head 1 is comprised of a plurality of body members that cooperatively define the interior volume 16 . A first body member 101 includes a sole portion and a face portion. The first body member may include a complete face 11 and sole 12 . Alternatively, either or both the face 11 and the sole 12 can be inserts coupled to the first body member 101 . The club head 1 also includes at least one second body member 102 coupled to the first body member 101 along the skirt 14 in known fashion. The crown 13 can be unitarily a portion of either body member 101 , 102 or it may be an insert coupled to either of the body members 101 , 102 . The second body member 102 includes a concave portion 20 that, when the body members 101 , 102 are coupled together, extends inward into the interior volume 16 . FIG. 2 shows an isolated view of an exemplary second body member 102 .
[0021] The first body member 101 preferably is formed of a metallic material such as stainless steel, aluminum, or titanium. The material of the first body member 101 is chosen such that it can withstand the stresses and strains incurred during a golf swing, including those generated through striking a golf ball or the ground. The club head 1 can be engineered to create a primary load bearing structure that can repeatedly withstand such forces. Other portions of the club head 1 , such as the skirt 14 , experience a reduced level of stress and strain and advantageously can be replaced with a lighter, weight-efficient secondary material. Lighter weight materials, such as low density metal alloys, plastic, composite, and the like, which have a lower density or equivalent density than the previously mentioned metallic materials, can be used in these areas, beneficially allowing the club head designer to redistribute the “saved” weight or mass to other, more beneficial locations of the club head 1 . These portions of the club head 1 can also be made thinner, enhancing the weight savings. Exemplary uses for this redistributed weight include increasing the overall size of the club head 1 , expanding the size of the club head “sweet spot,” which is a term that refers to the area of the face 11 that results in a desirable golf shot upon striking a golfball, repositioning the club head 1 center of gravity, and/or produce a greater moment of inertia (MOI). Inertia is a property of matter by which a body remains at rest or in uniform motion unless acted upon by some external force. MOI is a measure of the resistance of a body to angular acceleration about a given axis, and is equal to the sum of the products of each element of mass in the body and the square of the element's distance from the axis. Thus, as the distance from the axis increases, the MOI increases, making the club more forgiving for off-center hits since less energy is lost during impact from club head twisting. Moving or rearranging mass to the club head perimeter enlarges the sweet spot and produces a more forgiving club. Increasing the club head size and moving as much mass as possible to the extreme outermost areas of the club head 1 , such as the heel H, the toe T, or the sole 12 , maximizes the opportunity to enlarge the sweet spot or produce a greater MOI, making the golf club hotter and more forgiving.
[0022] The second body member 102 is light-weight, which gives the opportunity to displace the club head center of gravity downward and to free weight for more beneficial placement elsewhere without increasing the overall weight of the club head 1 . When the wall thickness of the second body member 102 is at the minimum range of the preferred thickness, a reinforcing body layer can be added in the critical areas in case the member shows deformations. These benefits can be further enhanced by making the second body member 102 thin. To ensure that the structural integrity of the club head 1 is maintained, these thin panels may preferably include a concave portion 20 . Inclusion of these concave portions 20 allow the second body member 102 to withstand greater stress—both longitudinally and transversely—without sustaining permanent deformation or affecting the original cosmetic condition, ensuring the structural integrity of the club head 1 is maintained. Preferred thicknesses for the first body member 101 include from 0.03 inch to 0.05 inch, while preferred thicknesses for the second body member 102 include from 0.015 inch to 0.025 inch. Preferably, the concave portion 20 displaces at least 10 cubic centimeters. More preferably, the concave portion 20 displaces at least 25 cubic centimeters. While the club head 1 can be virtually any size, preferably it is a legal club head. A plurality of concave portions 20 may be used with the club head 1 . For example, concave portions 20 of uniform or varying size may be positioned in the toe, heel, back, etc.
[0023] FIG. 3 shows a cross-sectional view taken substantially perpendicular to the face 11 of a second club head 2 of the present invention, and FIG. 4 shows a bottom view of the club head 2 . In the illustration of this embodiment, the concave portion 20 is positioned at the back of the club head 2 . The concave portion 20 preferably is not visible to the golfer at address. In addition to the concave portion 20 , the second body member 102 further includes a convex bulge 22 that extends generally away from the interior volume 16 . An insert 23 may be positioned within the convex bulge. The insert 23 is not visible from outside the club head 2 , and is thus illustrated using broken lines. In a preferred embodiment, the insert 23 is a weight insert. The convex nature of the bulge 23 allows the weight to be positioned to maximize the mechanical advantage it lends to the club head 2 . As shown in FIG. 4 , the club head 2 may include a plurality of convex bulges 22 , such as on a heel side and on a toe side of the club head 2 . The club designer may place inserts 23 as desired within the bulges 22 . The masses of the inserts may be substantially equal. Alternatively, one of the inserts may have a greater mass than the other. This may be beneficial to design the club to correct a hook swing or a slice swing. A preferred mass range for the weight insert 23 is from 1 gram to 50 grams.
[0024] As shown in FIG. 3 , the first body member 101 may comprise a majority of the sole 12 and the second body member 102 may include a majority of the crown 13 . This beneficially removes a large majority of the mass from the upper part of the club head 2 . In this embodiment the first body member 101 includes an attachment perimeter 18 that extends around its edge. The second body member 102 is coupled to the first body member 101 along the attachment perimeter 18 . The first and second body members 101 , 102 cooperatively define the interior volume 16 . The attachment perimeter 18 preferably may contain a step defining two attachment surfaces 18 a, 18 b. As illustrated, the second body member 102 maybe coupled to both of these surfaces 18 a, 18 b to help ensure a strong bond between the body members 101 , 102 .
[0025] While the body members 101 , 102 may be formed in a variety of manners, a preferred manner includes forming a complete club head shell (first body member 101 ) in known manner and removing material to create openings to which the second body member 102 can be coupled. The opening may be created in any desired manner, such as with a laser. The second body member 102 may be joined to the first body member 101 in a variety of manners, such as through bonding or through a snap-fit in conjunction with bonding. If a composite material is used for the concave inserts, molding six plies of 0/90/45/-45/90/0 is preferred.
[0026] While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. For example, while two body members have been described above, the present invention may be embodied in a club head having more than two body members. Additionally, the present invention may be embodied in any type of club in addition to the wood-type clubs shown in the illustrated embodiments. Thus the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. Furthermore, while certain advantages of the invention have been described herein, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
|
A hollow golf club head with a concave portion is disclosed and claimed. The club head includes a metallic portion and a light weight portion, which may be formed of plastic, composite, or the like. The concave portion allows the club designer to make a club head having very thin portions while still maintaining the requisite structural integrity. Convex bulges may optionally be provided to house weight inserts to enhance the playing characteristics of the golf club.
| 0
|
BACKGROUND OF THE INVENTION
This invention relates to a flat display panel, and more particularly to a sealing structure for a flat display panel such as a fluorescent display panel or a gas discharge tube which is hermetically sealed without a chip tube for exhausting air.
In the prior art, a flat display panel was provided with a chip tube projected therefrom for air exhaustion, but in recent years there have been demands for chip-less display panels.
Japanese Patent Application laid-open No. Sho 60-202637 laid open on Oct. 14, 1985 discloses a fluorescent display panel having a chip-less structure. In the disclosure initially, a through-hole is opened in the glass plate of an envelope. Then, after the inner electrodes are fabricated, the envelope is placed in a vacuum chamber and the through-hole is hermetically sealed in vacuum with a cover plate comprising a glass disk having a surface area larger than that of the through-hole.
This prior art chip-less display panel has the following defects.
(1) For exhausting air, the through hole must be bored either on an anode substrate or on a plate of the hermetically sealed envelope arranged opposite thereto. When the hole is bored on a glass plate of either the anode substrate or the opposite plate, an oil of high viscosity is used in order to prevent cracks and/or notches of the glass plate. Since the oil will stain the glass plate, a strong detergent is used to cleanse it. All these extra steps make the manufacturing process more complicated, and increase the manufacturing costs. Moreover, the super hard drill used in the manufacturing process is easily worn and further increases costs.
(2) The peripheral portion of the hole bored in the glass plate is prone to cracks, even if precautions are taken for working conditions. When the plate is heated to hermetically seal the envelope, cracks often occur and debris may adhere to the display segments made of a fluorescent material layer, thereby impairing the luminance thereof. As a result black spots will appear on the display and may result in defective indication by the display.
(3) Where a cover plate, comprising a flat glass disk is used to seal the hole, the cover plate protrudes from the sealed envelope.
SUMMARY OF THE INVENTION
An object of this invention is to provide a chip-less display panel with a structure which is manufactured by a process that does not involve a step requiring the opening of a hole in a glass plate.
Another object of this invention is to provide a flat type display panel of chip-less structure which has no projection and is easily manufactured.
According to this invention, two flat plates are placed in parallel upon the opposite primary surfaces of a spacer member to form an envelope. One of the plates is shortened to form a step with the spacer member or is cut into two portions to form a slit therebetween. Air is exhausted from the step or slit, and the spare is sealed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view to show the first embodiment of this invention.
FIG. 2A is a cross sectional view of FIG. 1 and FIG. 2B is a cross sectional view before a slit is sealed.
FIGS. 2C and 2D are cross sections of sealing members to be applied to the structure of FIG. 2B.
FIGS. 3A through 3C are cutaway perspective views of essential portions of an envelope of the first embodiment of this invention.
FIG. 4 is a perspective view to show the second embodiment of this invention.
FIGS. 5A and 5B are partially cutaway perspective views of FIG. 4.
FIG. 6 is a perspective view of the third embodiment of this invention.
FIGS. 7A and 7B are partially cutaway perspective views of FIG. 6.
FIG. 8 is a perspective view to show the fourth embodiment of a cover plate according to this invention.
FIGS. 9A and 9B and FIGS. 10A and 10B are perspective views to show other modifications of the cover plate.
FIG. 11 is a perspective view to show the fifth embodiment of this invention.
FIGS. 12A and 12B are partially cutaway perspective views of FIG. 11.
FIG. 13 is a perspective view to show the sixth embodiment of this invention.
FIGS. 14A and 14B are partially cutaway perspective views of FIG. 13.
FIGS. 15A and 15B are perspective views to show the seventh embodiment of this invention.
FIGS. 16A and 16B are plan view and front view to show an inner cover plate provided with glass-solder paste.
FIG. 17 is a cross sectional view to show how the inner cover plate is placed in an envelope in a vacuum chamber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An application of this invention is a fluorescent display panel is now described referring to the drawings.
Referring to FIGS. 1A, 2A and FIGS. 3A-3C, an envelope of a fluorescent display panel comprises a pair of insulating plates 1 and 4, one 1 being an anode substrate and the other 4 being a cover plate, and a frame-shaped spacer 3 held therebetween. Display electrodes 103 (segments) having a fluorescent material layer 104 are formed on the anode substrate 1. The electrodes 103 are connected to internal wiring layers 108 provided below an insulating layer 107 and led-out from the envelope via a group of external leads 2. A group of external leads 2 are held between the spacer 3 and the anode substrate 1 and sealed therein with sealing material such as soldering glass which connects the spacer 3 to the substrate 1. The cover plate 4 is hermetically fixed to the spacer 3 with soldering glass. In this embodiment, one side of the cover plate 4 is cut off to shorten the length of the cover plate 4 to such extent that the length is less than the length of the substrate 1 by a value little more than the width of the spacer 3. Thus, a slit W is formed between the spacer 3 and the cut-down side of the cover plate 4 as shown in FIG. 2B. An elongated opening, or a slit, thus formed is used to exhaust air inside the envelope. A glass rod or a like insulating rod 5 is used as a sealing member to close the slit and is sealed with soldering glass 6 (see FIG. 2A).
The outer diameter of the insulating rod 5 is determined to be larger than the space W of the slit and not greater than the thickness of the cover plate. The length thereof is selected to be long enough to cover the elongated opening of the slit and not to protrude from the envelope. The insulating rod 5 may be in the form of a rod as shown in FIG. 2C or of a pipe 7 as shown in FIG. 2D.
As shown in FIG. 2A, when the electrode is of mesh pattern or transparent, the anode substrate 1 is made to be transparent so as to be observed from the side of the anode substrate 1. To this end, usually a plate of glass is used for the anode substrate. Needless to say, observation can be done from the side of the cover plate 4 by using a glass plate for the plate 4. The other surface or the side not indicating may be of a ceramic plate, but a glass plate is usually used to reduce a cost. With a sealing member 5 or 7 in the form either of a rod or a pipe to close the air-exhausting slit, the fluorescent display panel of FIG. 1 has no portion protruding from a hermetically sealed envelope.
This structure can also minimizes the size of necessary components. The hermetically sealed envelope can be composed of the anode substrate 1, the cover glass plate 4, the spacer 3 and the sealing member 5. As shown in FIGS. 3A to 3C, length L 1 of the cover plate 4 is shorter than the value of L 2 -T by W, wherein L 2 represents the length of the spacer 3 and T represents the frame width of the spacer 3. The length L 3 of the anode substrate, is selected to be equal to or larger than the length L 2 .
The sealing process with soldering glass 6 is advantageous. As the glass rod 5 has a circular section, sealing process starts from the portions of linear contact with the end wall of the cover plate 4 and the upper surface of the spacer 3 to gradually proceed to other portions. This procedure can eliminate automatically the problem in strength which might otherwise be caused from the difference in thickness between soldering glass on interfaces in the case of surface-to-surface contact. More specifically, this structure can obviate the problem that the strength in adherance will be weaken when the thickness of the soldering glass 6 is less than a certain value. In the process of melting the soldering glass 6, the soldering glass can seal snugly and completely one object with another object due to the effect of its surface tension.
Problems otherwise caused with powder of soldering glass can be reduced by pre-sintering process after applying at least a portion of soldering glass for sealing on the cover member 5 which is either a rod or a pipe.
In the above embodiment, an insulating rod is used as the sealing member, but as shown in FIG. 4, a cover plate 52 of a rectangle may be used. More particularly, as shown in FIGS. 5a and 5B, one end of an insulating plate 42 having the dimension large enough to cover the entire spacer 32 is cut off to form a rectangle as the cover plate 52. The slit for exhausting air in this embodiment is therefore in the form of a rectangle. The slit between the cover plate 52 and an insulating plate 42 is filled with sealing material 62 to be sealed. The anode substrate 12 on the side of electrodes is similar to one shown in FIG. 1 and FIG. 2A.
In the embodiment shown in FIG. 6, a cover plate 53 is shaped as a triangle. This can be obtained by cutting one corner of an insulating plate 43 as shown in FIGs. 7A and 7B. In the case like this embodiment where the dimension of the envelope is relatively large, it is preferable to select a triangle for the configuration of the exhausting slit which should be formed by notching off a glass plate covering entire region of the spacer 33 to produce the insulating plate 43 and cover plate 53. In the case of a rectangular envelope as shown in FIG. 4, a glass plate covering entire region of the spacer 32 may be notched in parallel to a shorter side thereof to produce the insulating plate 42 and cover plate 52.
An application of a flat cover plate is by no means limited to the above-mentioned embodiments. For instance, an insulating plate covering entire spacer 34 may be cut diagonally at one end thereof to form an insulating plate 44 and a cover plate 54 in the form of a trapezoid as shown in FIG. 8.
Instead of cutting off a portion of an insulating plate, a cover plate may be a rectangular metal cover plate 521 or a triangle metal cover plate 531 which are separately prepared to correspond the cover plate 52 or 53 as shown in FIGS. 9A and 9B. Metal supporting members 522 and 532 may be connected in advance to the cover plates 52 and 53 as shown in FIGS. 10A and 10B.
The embodiment shown in FIG. 11 has an almost similar appearance to the one shown in FIG. 4, except that a spacer 34 is bent inward into a frame at one end thereof 341 a shown in FIGS. 12A and 12B, and the extension line thereof b--b' coincides with the cutting line B--B' between the insulating plate 42 and the cover plate 52. By molding the spacer to correspond to the cutting line of the cover plate, shavings or dust of soldering glass and glass plate can be prevented from entering the envelope in the sealing process.
The embodiment shown in FIG. 13 is almost similar to the one shown in FIG. 6 in appearance except that a spacer 35 is bent at one end 351 thereof toward inside as shown in FIGS. 14A and 14B to extend along the line c--c' which coincides with the cutting line C--C' in FIG. 13.
FIGS. 15A and 15B show the configuration of a spacer 36 for the case where a cover plate shown in FIG. 8 is used. The spacer 36 is bent toward inside at one end 361 thereof to extend along the line d--d' which agreed with the cutting line D--D'.
Referring to FIG. 16, for example of manufacturing process of the fluorescent indicator panel having the structure shown in FIG. 4 will be described.
As shown in FIGS. 16A and 16B, a plain view and a front view of a cover plate 52, respectively, a surface of cover plate 52 to be sealed is applied with solder glass paste on the region facing the spacer 32 and the section facing the end of the insulating plate 42, and subsequently pre-sintered. As shown in FIG. 17, the spacer 32 and the insulating plate 42 are applied with solder glass paste 62 on the surfaces facing the cover plate 52 similarly, and then are pre-sintered.
These are placed at predetermined positions inside a vacuum chamber (not shown). For instance, as shown in FIG. 17, essential portions of an envelope are sealed in advance on a panel and then positioned in the panel with an exhausting slit on a supporting plate 201 having a recess to house the cover plate 52. The vacuum chamber is exhausted of air, and then a pushing rod 202 is inserted through an opening bored on the bottom of the recess and is pushed in the direction indicated with an arrow mark to press the cover plate 52 onto the spacer 32. Then the pre-sintered solder glass 62 is heated to seal the exhausing slit. It is preferable that the melting point of the pre-sintered solder glass 62 is lower than that of solder glass used to seal the other portion of the envelop by the value of 50° to 80° C.
In an ordinary fluorescent display panel, since filament supporters are located at both end portion of the panel, cover member of the present invention does not disturb the observation of display.
In the foregoing description, although the present invention has been applied to the fluorescent display panel, a gas discharge display panel can also employ the present invention by providing an exhausting port at the place where the electrodes are not provided.
This invention can achieve the following effects.
(1) It enables manufacture of a display panel which is substantially in a box form without projections at a high yield and at low cost so as to provide a display panel of chip-less type which is easily packaged on devices.
(2) As the processing and working of the components of a chip-less type display panel can be simplified, the manufacturing process can be automated or mechanized. As the problem heretofore caused by powder and dust can be obviated, the manufacturing yield can be improved and the cost can be lowered to provide a highly reliable display panel.
The present invention has been described in the foregoing statement by referring to the embodiments shown in attached drawings, but the position of the exhaust air port may be on the side of the longer side of an insulating plate or of the electrode substrate in respective embodiments. By selecting the position alone, eight variations and modifications will be possible. The present invention is therefore by no means limited by the particular position of the air exhaust slit.
|
A flat fluorescent display panel, having in parallel an anode plate and a cover plate separated by a frame-type spacer whose central open area defines an inner space for a fluorescent material and electrode structure. The three layers are joined and sealed together such that the inner space may be evacuated. The cover is cut or slit, forming an opening that expose the inner space and permits evacuation. The opening is closed and sealed by a portion of the cover or some suitable sealing structure.
| 7
|
BACKGROUND OF INVENTION
1. Technical Field
The present invention related to crocheted balls and, more particularly, relates to crocheted balls having an embroidered portion thereof.
2. Related Art
The utilization of spherical crocheted objects for toys, games and recreations have been increasingly popular over the past several years. Initially, crocheted balls were made and sold as toys through many retailers. Now crocheted balls have many additional uses in sports and recreational activities because they are soft, colorful and inexpensive to produce. Crocheted balls and bags have become very popular for use in sports that utilize soft balls including footbag, juggling, toss ball, kick ball, dodge ball and others. Thus, due to their popularity and wide distribution, spherically crocheted objects make an excellent item for advertising and promotional purposes.
One of the more popular utilizations of the spherical crocheted objects is for the game of footbag. An originating patent, U.S. Pat. No. 4,151,994, for the game was issued in May 1979 to Robert J. Stahlberger, Jr. the inventor of the game of footbag (Hacky Sack™). The original ball that was used for this game was a leather paneled style of ball shaped like a baseball. Years later, this original invention was improved upon with the introduction of several newer styles of footbags that touted improved characteristics for the playing of the game. These improved characteristics included a softer style of ball and low bounce characteristics that allowed for greater control and ease of use by the footbag players, who enjoyed the ability to “catch” the ball with the foot and perform a much wider array of athletic footbag tricks. One of the more popular ball types for the game has become the crocheted footbag.
Crochet is a fabric construction that utilizes needlework consisting of the interlocking of looped stitches formed with a single thread and a hooked needle. The popular crocheted ball is a successful implementation of crochet stitching in a round form. Thread types used include cotton, rayon, dacron, polyester or a combination of several thread types. The thread used is of varying degrees of thickness. Depending on the thickness and type of the thread, a crocheted ball will contain larger or smaller stitches which give the ball an appearance of being fuzzier, thicker or rougher. Crocheted balls are made of varying sizes, weights and looseness based on the game played, preference of the participants of the sport, durability and cost. All spherical crocheted objects can be woven by machine or by hand.
Spherical crocheted objects are woven such that rows contain increasing numbers of stitches expanding outward in a spiral form. Thus, the start of a crocheted ball (the “bottom”) starts with a single stitch; which is added to in a spiral pattern. This spiral construction soon forms a round disc. The spherical shape forms as the disc construction expands and the stitches are tightened to create a curvature. In the middle of the crocheted ball, the rows contain their maximum number of stitches and determine the diameter of the crocheted ball. For instance, if there are 10 stitches per inch then a ball 8 inches in diameter will contain 80 stitches.
As a crocheted sphere is woven, and after it reaches its maximum diameter, the number of stitches per row is reduced. Thereafter the reduction of each successive row gives the ball its shape and the stitches get tighter and closer together. Before the crocheted sphere weaving is completed, a small hole remains. Before the final closure, the ball is filled with a filling type, which is often plastic resin pellets, bird seed or other types of small or inert filling; then the crocheted object is sealed shut with the final crocheted weave and tied off in a knot. A spherical crocheted object is usually seamless and durable with the final sewing termination.
The filling of a crocheted ball determines its characteristics: slackness, feel and the best utility.
Manufacturers have chosen many different filling types and sizes. Crocheted balls are quite durable, seldom rupture and thus can be used in the most active and aggressive games with little chance of breaking open.
The simplicity and low production cost of the crocheted ball is ideal for many applications in games, sports and toys. Crocheted balls are superior for the purpose of game balls because they are very durable while being malleable and soft at the same time. This offers a longevity not found with paneled balls which tend to break open at the seams. The stresses on the fabrics during the use of crocheted balls are dissipated throughout the stitches of the ball as compared to that of a paneled ball which have limited stitches.
Prior to this invention, spherical crocheted objects have been limited in their ability to purport messages. Previous utilizations were predominantly limited to fabricating crocheted balls with designs built entirely into the crocheted construction. Thus, the primary method has been to directly crochet images into the actual weaving by means of changing the colors of the threads on each individual stitch, usually by hand, to create the necessary contrast to create such images. Although images and logos implemented on existing crocheted balls can be quite complicated and intricate, the fact remains that crocheted balls are limited by the number of stitches per inch inherent in the manufacture of such balls, usually 10 stitches per inch or less, depending on the thickness of the thread used.
Alternative utilizations applied to crocheted balls for the purpose of creating a more useful advertising medium have included other attempts to modify their construction. One known attempt has been the addition of a round panel of fabric sewn into the crocheted ball. This panel, which can be of imitation suede or another durable material, is suitable for screen printing and other suitable advertising purposes; however, there are problems with this incarnation. The basic strength of the ball is dubious due to a fixed fabric seam that is incapable of handling the stresses of hard play, and has been known to come undone. Additionally, the fabric is less flexible than the original crocheted stitches so the ball does not function as well for the preferred active sports that require a softer ball.
Still other manufacturers have attempted variants on crocheted balls to enhance the ability to purport messages or logos. Directly dyeing the crocheted threads is a less successful method of applying words, logos or advertising messages since it is often messy and unprofessional in outcome. Further still, a panel of fabric has been sewn to the exterior of crocheted balls as a means of applying a logo or message. This application is also limited because the size of these fabric pieces must be very small and do not stick well to spherical objects when glued or sewn.
In summary, spherical crocheted objects are inexpensive and mass-produced items used for various sporting, recreational and advertising purposes. To date, the several known attempts to extend the message-carrying functionality of these crocheted objects have had limited success.
SUMMARY OF INVENTION
The invention changes the procedure and method by which a spherical crocheted object is made. The spherical object no longer contains the limits of low quality or low resolution graphics for the purpose of adding an image, a message, logo, words, name or motif. Utilizing our specific production process allows for the inclusion of an embroidery step during the construction of the spherical crocheted object, enhancing the usefulness of products, games and diversions that utilize them.
The embodiment specifies fabrication steps that allow for the addition of an embroidered logo of a limited size. The size restrictions depend upon the size of the final crocheted ball and more specifically, the size of the initial disc of crocheted fabric upon which the embroidery is sewn. This initial disc should not be more than about 30% of the size of the diameter of the spherical crocheted object. Thus, even though crocheted balls are round, our embodiment avoids attempting to crochet on a round object since current technology embroidery equipment does not effectively sew on spherically constructed objects of closed construction, particularly on crocheted or woven balls of loose and fairly thick thread.
In the current embodiment, spherical crocheted objects, such as crocheted balls, are the recipients of the placement of an embroidery message or logo. Crocheted balls are popularly utilized as toys as well as the primary object of several games and sports, such as juggling and Hacky Sack™, also known as the game of footbag, and other games that require a low impact or soft ball that is durable and often malleable.
Prior to our embodiment previous methods of carrying logos or other publicity images on spherical crocheted object were limited, of low quality, too complicated and of a decorative or ornamental nature mainly. The inherent limitations of the medium of construction the loose and thick crocheted stitching meant that inexpensive crocheted balls were less effective tools for promotion by those seeking inexpensive toys or objects for advertising or incentive purposes. Previous attempts at utilizing crocheted balls required that the messages or advertising images be constructed during the initial construction of the spherical crocheted object, on a stitch-by-stitch level, by using different colored threads that were woven to form a crocheted ball. Still other methods have proven less effective on crocheted balls as compared to direct embroidery processes that allow for a much higher quality and higher resolution output.
Of further importance, but no less significant, is the fact that spherical crocheted object can be quite inexpensive to manufacture. This production process has solved the conundrum of utilizing the inexpensive crocheted ball for the purposes of carrying a high quality embroidered figure or message so that the ball may be utilized more effectively in publicizing an embroidered logo, name, motif, image, worded message, monogram, picture or illustration. Thus, the popular inexpensive crocheted ball can now be utilized as a higher quality medium for publicity purposes, advertising tools, corporate premiums, logo messages, or sports tool touting a team logo.
The invention calls for the modification of the fabrication of the crocheted ball so that it is capable to be sewn by high production embroidery machinery. After the embroidery is finished and the ball is completed according to the guidelines contained herein, the crocheted ball retains its round shape, its noteworthy durability and at the same time becomes a more useful advertising and promotion tool.
BRIEF DESCRIPTION OF DRAWINGS
For a fuller understanding of the invention and the process of producing a spherical crocheted object inclusive of embroidery steps, please refer to these drawings in which:
FIG. 1 illustrates a three dimensional view from an elevated and angled aspect of an unadorned ball in a typical size constructed using standard crocheted weaving;
FIG. 2 illustrates a bottom view of a crocheted ball that contains the figure of a star that has been embroidered directly onto the crocheted ball according to the present invention;
FIG. 3 illustrates a three dimensional view from an elevated and angled aspect of a ball containing a star in a contrasting color to that of the base color and that has been crocheted entirely within the ball according to the prior art;
FIG. 4 illustrates a bottom view of a representation of the crocheted initial disc showing individual crocheted stitch detail according to the present invention;
FIG. 5 illustrates a bottom view of a representation of the crocheted initial disc showing individual crocheted stitch detail after the placement of a representative embroidered star figure according to the present invention;
FIG. 6 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted initial disc showing individual crocheted stitch detail after the start of the cylindrical walls according to the present invention;
FIG. 7 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted ball construction showing individual crocheted stitch detail inclusive of nearly complete cylindrical walls according to the present invention; and
FIG. 8 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted ball construction showing individual crocheted stitch detail inclusive of cylindrical walls and woven top preceding final seamless closure according to the present invention.
DETAILED DESCRIPTION
The invention is embodied in the process by which a basic spherical crocheted object, such as a ball, FIG. 1 , is fabricated. Additional fabrication steps transform this simply and inexpensively manufactured object, consisting of crocheted rows of thread 11 , into a more functional object for displaying a message, logo, words or logo.
FIG. 2 demonstrates the detail when applied to a crocheted ball according to the present invention. A star, 12 , is directly embroidered on top of the crocheted ball. Sewing of the embroidery is preferably a step separate and outside of the basic crocheted fabrication. The nature of the embroidery sewing disclosed herein possesses great detail advantages over crocheted objects. Although images, figures and logos fabricated on crocheted objects can be quite complicated and intricate, the fact remains that crocheted objects are restricted in the number of stitches per inch inherent in the manufacture of such objects.
The limitations of the crocheted construction are further evident in FIG. 3 which shows a crocheted star, 14 , woven directly into a crocheted ball as is known in the art. This is the most common method of adding artwork or a logo to a crocheted object. It is apparent in FIG. 3 that the star does not elucidate a sharp image. The crocheted star is crude, “blocky,” and of minimal detail.
The embroidery sewing of the star 12 , in FIG. 2 , on the other hand, elucidates a sharp image. One reason for the sharpness of the embroidery sewing is that the stitches in a crocheted object are large as compared to embroidery stitches. Crocheted thread typically contains more plies, or bundles, of heavier weight thread than embroidery thread. Crocheted thread must be thicker and more rigid to be more effectively used with a hooked crochet needle. Crocheting, although appropriate for knitting sweaters and afghans, does not serve well for highly detailed tasks that call for a high amount of detail. On the other hand, embroidery, especially machined embroidery, can utilize many types of thread of a thinner and more supple variety with fewer plies. Embroidering equipment usually uses rayon or polyester thread, which is strong and thin, but can also use thread as fine as silk for highly detailed embroidery stitching.
In FIG. 3 the crocheted stitches contain typically, 10 stitches, or lines, per inch. By contrast, the embroidered stitches 13 , in FIG. 3 , reveal lines of thread as depicted by the comb teeth-like edge between the black and white arms of the star figure and contain high resolution detail.
For every crocheted stitch, there are approximately 8 lines of embroidery. This equates to about 80 lines per inch, or 8 times the number of lines per inch as compared to the crocheted ball examples. Other crocheted objects, when compared to embroidery objects, educe similar quality comparisons.
Specific steps contained herein must be followed to permit the addition of the more detailed embroidery process upon spherical crocheted objects. In the drawings, the fabrication of a crocheted ball is being shown. An initial step in creating the ball is to establish a starting point, 16 , and crochet in a circular pattern as depicted in FIG. 4 . Each individual crocheted stitch is represented by a cross hatched unit because thread used in a crocheted project typically contains multiple plies. In actuality, a crocheted stitch is less clear as the drawing representation in FIG. 4 because crochet thread tends to twist, fray and coalesce, becoming less distinct than the drawing depicts. The first three drawings are better representations of an actual crochet object which shows the thread as thick filaments.
As the crochet stitches are added, they are attached to each proximate stitch as shown in item 15 . Likewise, as the stitches are added in a circular motion, they are attached to the proximate row as shown in item 17 using the hooked crocheted sewing technique as depicted in item 18 . This technique is the origin for the durability of spherical crocheted objects. In addition, the crocheted object attains the ability to stretch and deform due to a general slackness in this type of multi-plied weaving.
An aspect of producing a spherical crocheted object is the creation of an “initial disc,” the product shown in FIG. 4 . This initial disc is the base from which the embroidery is fashioned. It is imperative that the last stitch in the construction of the initial disc be tied off so that it does not come unwound. The initial disc must be substantially flat so that it can fit into the commercial embroidery machines for quick and effective stitching. Thus the stitches of the initial disc should not be tightened with each successive woven row. The stitching is created as one would create a flat weaving such as a placemat, coaster or other woven article with the stitches flaring out so that no shape is started. This differs from the current construction of spherical crocheted objects and is one important element of the invention.
The initial disc can be of any crocheted stitch combination upon which embroidery is placed. A solid color is a common choice although crocheted designs can still be used for the initial disc creation. Usually contrasting colors are chosen so the embroidery is visually recognizable and distinct. Any combination of thread colors can be chosen for the embroidery step. Many commercial embroidery machines can be loaded many different color threads so that an entire multi-color design can be done in a few seconds.
It is also important that a diameter of the initial disc is not larger than about 30% of the final circumference of the spherical crocheted object. Thus, for example, in a preferred embodiment, if the spherical crocheted object will have a final circumference of approximately 7.5″ inches, the initial disc must be no more than approximately 2.25″ inches in diameter when lying flat in order to work best for the embroidery. As the width of the initial disc exceeds 30%, the crocheted object will turn out less spherical, and will look oblong or misshapen. The diameter of the initial disc can be smaller than 30% of the final total circumference; however, a smaller initial disc reduces the area available for the embroidery. It is the upper threshold to which must be observed and adhered in the embodiment. Since the aim is to create an area upon which the higher quality embroidery may be sewn, and a discernible message may be advertised, the goal of maximizing the initial disc size is advised by keeping the diameter of the initial disc about 30% of the final circumference of the spherical crocheted object.
A next step of the invention is to utilize a commercial grade, high quality modern embroidery machine to directly embroider the logo on a substantially flat or the non-curved initial disc. Examples of commercial grade embroidery machines are the Tajima Bridge Type Cylindrical Frame Machine line, the SWF model 1508 multi-head embroidery machine or other equivalent commercial grade machines, either multi-head or single head. Other embroidery machines can be utilized for this step, but for quantity production, the multi-headed machines will function better than the single headed machines. Although machine embroidery is preferred, the embroidery can also be applied by hand. Some embroidery equipment is made for special functions and a wide range of options are available to individuals seeking to create artistically appealing thus effective logos or images.
It is, however, important that the embroidery does not exceed the diameter of the initial disc. In FIG. 5 , the length of the embroidery is less than 2.25 inches because, in our drawing, this is the diameter of the initial disc. The needle of the embroidery machine should, in fact, remain at least one, preferably two embroidery rows away from the edge of the initial disc as depicted by the separation of the two pointers in item 19 . This way a solid and a well defined embroidery logo can be woven firmly onto the initial disc, such as the sample star, 12 . It is advised that no paper or fabric backing is used during the embroidery, which is a common step when embroidering with high quality embroidery machines. These backings tend to offer support to the embroidery whereas the article in question for this embroidery is a crocheted disc that needs to remain soft and pliable after the embroidery fabrication step. However, it is up to the manufacturer to determine the final “feel” of the spherical crocheted object. Selecting or not selecting an embroidery backing will affect this result.
The embroidery should then be finished off. Once disconnected from the embroidery machine, all loose threads should be tied off or cut on the front side of the “initial disc.” The back side the initial disc may contain loose and unfinished threads. This is acceptable because this portion of the initial disc will be located on the inside of a spherical crocheted object. Although not important to the embodiment, it may be the choice of the manufacturer to trim the extra threads to avoid difficulties in the later fabrication steps, although the economy and complexity of the project may influence this decision. With the completion of the embroidery, the initial disc is ready for the next step of the weaving process.
The next step of the process of an embodiment is illustrated in FIG. 6 and performed on our initial disc. The final stitch that had been tied off is untied and the crochet process continues, only this time the rows are tightened so that the row of stitches bends upward, item 22 , starting at point 21 . Each successive row of crocheted stitches are woven in a spiral fashion flaring out from the initial disc, 20 , and each stitch is hooked into the row beneath it as with the initial disc construction.
This is a crucial point in the fabrication process of the embodiment. Since the initial disc is flat, the ball must be woven so that it forms a spherical object or ball, and to accomplish this, each stitch must be pulled upward as woven at 23 , and tightened before they are hooked together. The loose threads, 24 and 25 , are crocheted and build upon the rows consecutively. If the color of the crocheted ball is to be solid, then the continuation of the weaving should include the identical color thread; if additional designs are to be included in the final spherical crocheted object, this is a logical point to initiate a thread color change for the creation of a crocheted design on the object.
As successive rows are added to the previous row, a cylinder takes shape as shown in the FIG. 7 , which looks somewhat like a cylindrical wall with successive and stacked rows of crocheted stitches, 35 through 43 . As noted in FIG. 7 , the construction of the cylindrical wall is akin to the “side” of the crocheted ball and the bottom, the initial disc, being the initiation point and center that contains the embroidered figure. The top will be the final termination and closure point of the ball. Thus, the ball has a top and bottom for the purposes of our embodiment description and the cylindrical wall will have a center, or point of maximum diameter, which in our drawing lies between rows 38 and 39 because there is an even number of rows. For a construction with an odd number of rows, there would be one row designated as the row of maximum diameter, or center.
A crucial aspect at this important construction stage of an embodiment is in calculating and duplicating the number of stitches per row. The number of stitches per row will vary depending on the size of the initial disc which, as mentioned before, is determined by the desired size of the embroidery logo and the desired size of the crocheted ball. Independent of the ball size, a formula can be utilized for the purposes of the embodiment that will direct the manufacturer to make a crocheted ball that will retain its all important round shape.
In the first row of the crocheted cylindrical wall, it is important to note the number of stitches and abide by some conditions when building upon the cylindrical wall rows. First, the number of stitches should never be reduced when building up the cylindrical walls. The counted stitches may be kept the same or increased slightly to the point that which the maximum diameter of the ball is attained. Reducing the stitches in the successive rows will cause the ball to be misshapen, an undesired result. In FIG. 6 , the successive rows contain 60 stitches each. All the rows in the cylindrical walls contain 60 stitches. If rows 35 through 38 contained less stitches than the previous, then the ball may end up misshapen. However, if row 35 contained 61 stitches and row 36 contained 62 stitches, this would be an acceptable iteration for this construction.
The point that which the maximum diameter of the spherical crocheted object is attained is another calculation that is important in the construction in accordance with our embodiment. It has been found that to make a spherical crocheted object like a ball, the cylindrical sides of the ball should have a number of rows that is between around 36% and around 46% of the total number of rows in the construction of the ball. In our drawing, FIG. 5 contains 10 crocheted rows in the cylindrical wall of this crocheted ball which is approximately 38.5% of the total number of rows of this ball construction. In this drawing and in this sample, there are 10 rows on the cylindrical wall. In our drawing it can be determined that the center, or diameter, of the ball is between rows 38 and 39 from the bottom of the cylindrical wall. However, this value can be determined in advance by calculating the midway point in the cylindrical wall using our estimate of acceptable wall size, which can be estimated in advance to be between rows 38 and 39 .
Next, once the maximum diameter of the ball is attained, it is acceptable to reduce the number of stitches per row, for rows 39 through 43 ; or to maintain the same number of stitches in the ball, in order to maintain a round ball. It is not recommended to increase the number of stitches or again a misshapen ball will result. In large scale production, it may be unreasonable to count stitches, so maintaining the same number of stitches for each row in the middle is an acceptable and advisable practice. Once the ball is complete, due to the nature of crocheted stitches, the threads will stretch giving the ball its desired round shape.
It must be noted that the construction of a spherical crocheted object is not a precise science and variations will arise. Variables include the thickness of the thread, size of the stitches and slackness of the stitches. In addition, for the construction of a spherical crocheted object, there is often no definite demarcation as to where the cylindrical wall starts and the bottom construction ends, particularly once the first row in the cylindrical wall is begun and tightened, which tends to warp the entire construction upwards, forcing it into the shape of a ball. Thus, we have supplied relative percentages for the purposes of calculating the proper construction of the embroidered crocheted ball; however, these values are quite close and have been determined over repeated testing and constructions.
In our embodiment, the point at which it can be determined that the cylindrical walls have ended ( FIG. 7 , item 44 and 45 ) we complete the top of the embodiment. Taking the remaining loose threads, 46 , we start to crochet the top of the ball, bending them as stitches are added as shown in FIG. 8 . This crocheting step will generally match the bottom initial disc, 20 , of the crocheted ball (in terms of size and number of rows) which contains the embroidered portion of the construction. The embroidery portion can not be viewed in FIG. 8 because it is on the bottom of the ball.
It is important to leave a small hole, 28 , in the top of a spherical crocheted object. This hole is where a filling is inserted and a final closure is made. The ball is typically filled with plastic pellets or some other desired filling. The volume percentage of the filling will determine how slack or firm the ball feels. A large number of manufacturers that utilize the crocheted ball for the game of footbag use plastic pellet filling of approximate 2 millimeters diameter in size, of varying shapes, and choose to loosely fill the crocheted ball with from 40 to 75 fill percentage to give the ball the low bounce characteristics desired by many of the players of the game. Manufacturers of crocheted juggling balls tend to fill the crocheted ball with 100 percent fill to give the ball a harder feel and an easier grip which is more suitable for their sport. Many other fill types and combinations exist. In our embodiment, filling and closure are all part of the normal manufacture found in the production of crocheted balls. Note in FIG. 8 that a hole has been left with two loose threads, 24 and 25 . Commonly the extra thread is left to perform the final closure after filling. The final closure is done using the crochet hooked needle and tied off to seal the construction.
Due to the pliant and soft nature of the thread materials such as those used in the fabrication of spherical crocheted objects, once completed, the object will lose the cylindrical shape and transform into the shape of a ball. This transformation can be accentuated by compressing or kneading the ball under pressure which will stretch out the stitches to give the crocheted ball a more round appearance, and will enhance the playability features desired in a ball of this type.
By following the construction process laid forth herein, a spherical crocheted object will have been successfully created that contains an embroidered logo and that can be duplicated on a large scale.
|
A spherical crocheted object includes a portion that contains high quality embroidery and is made beginning with a fabric piece called an initial disc. By initially knitting the spherical crocheted object into a flat, round disc of specific and limited dimensions, this initial disc is created for the introduction of an external embroidery process. The crocheted initial disc is tied off to maintain durability during the embroidery step, which is usually performed on specialized embroidery equipment. Thereafter, by vigilantly following specific construction techniques, a ball will be produced that retains its spherical shape resulting in an end product with characteristics similar to that of a spherical crocheted object that does not contain embroidery.
| 3
|
This application is a continuation of application Ser. No. 07/711,978, filed Jun. 7, 1991, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to percussion devices, and more particularly to piston valve which supply air to percussion devices.
Present piston valves for percussion devices include multiple parts. One embodiment of prior art percussion device includes the valve cover, disk valve, valve chest, belleville washers and housing plug. All of these parts, excluding the belleville washers, are formed from fully hardened steel which are expensive and complex to machine.
The prior piston valves require close tolerances between the piston valve sides and the valve bore since the two members are coupled together. These close tolerances require machining processes. Even after the finishing, the outside diameter of the piston valve often is somewhat eccentric with the valve bore. The piston valve with close tolerances often conflict with non-perpendicular shoulders of the housing.
The prior piston valves also utilize rigid valve pistons to control the flow of air to the piston. Since the rigid valve piston oscillates so many times within the valve bore, the selection of materials which to construct (and the associated heat, wear and shock) the piston valve cartridge from which can withstand these oscillations is extremely limited. Plastics, in particular, can not withstand the type of oscillations required for the prior rigid valve piston.
In the prior art configuration, the rigid valve pistons travel relative to the adjacent bore. Often the piston cavity will get dirty and clogged and restrict smooth passage of the valve piston within the valve cavity.
The foregoing illustrates limitations known to exist in present percussion apparatus piston valves. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
SUMMARY OF THE INVENTION
In one aspect of the present invention, this is accomplished by providing a valve diaphragm for a percussion apparatus including a valve portion having a diaphragm bore and a fluid supply source. A piston having a first piston surface and a second piston surface are also included. A diaphragm is mounted in the diaphragm bore and is displaceable in a first direction which permits fluid communication between the fluid supply source and the first piston surface and limits fluid passage between the fluid supply source and the second piston surface. Displacement of the diaphragm in a second direction permits fluid communication between the fluid supply source and the second piston surface and limits fluid passage between the fluid supply and the first piston surface.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURE
FIG. 1 is a side cross sectional view illustrating an embodiment of percussion apparatus involving a piston valve cartridge with a diaphragm of the present invention;
FIG. 2 is an exploded cross sectional view of the encircled portion labelled 2 in FIG. 1;
FIG. 3 is a view similar to FIG. 1, except with the diaphragm being displaced in a second diaphragm direction and the piston being displaced in a first piston direction;
FIG. 4 is a side cross sectional view of alternate embodiment of diaphragm of the instant invention; and
FIG. 5 is a side cross sectional view of yet another alternate embodiment of diaphragm of the instant invention.
DETAILED DESCRIPTION
In this disclosure, identical elements in different embodiments and figures will be provided with identical reference characters.
A percussion apparatus is illustrated generally as 10. The percussion apparatus includes a housing 12, a piston 14, an air inlet 16, an actuator handle 18 and a valve cartridge 20. A piston bore 22 is formed in the percussion apparatus, wherein the piston 14 may reciprocate within the piston bore 22. The piston has a first piston surface 36 and a second piston surface 42, which is opposed to the first piston surface.
The valve cartridge 20 includes a diaphragm 24 which reciprocates within a diaphragm cavity 26. The diaphragm circumferential edge portion 28 is formed from a flexible material wherein displacement of a diaphragm center portion 30 is permitted while the edge portions 28 remain approximately immobile relative to a diaphragm cavity lateral wall 32. Since the diaphragm does not slide relative to the diaphragm cavity wall 32, wear and heat is greatly reduced compared to the prior art. This lack of wear permits use of different materials than the heat treated steel which is used in the prior art piston valves.
The center portion 30 of the diaphragm 24 may be formed from a rigid or a flexible material depending upon design choice. FIGS. 1-3 illustrates a configuration where two rigid plate portions 31 are affixed to either side of the diaphragm. Alternately, a single plate may be adhered to only one side of the diaphragm as illustrated in FIG. 4, or the edge portion may be formed about a rigid central portion 35 as illustrated in FIG. 5. Finally, a single flexible member with no rigid portion will suffice as a diaphragm 24.
The function of the piston valve cartridge 20 is to communicate air alternately to a first port 33 which is in fluid communication with the first piston surface 36 and a second port 40 which is in fluid communication with a second piston surface 42 depending upon the position of the piston. Application of pressurized fluid to a first piston surface 36 tends to bias the piston 14 in a first piston direction 70a. Application of pressurized fluid to the second piston surface 42 tends to bias the piston 14 into a second piston direction 70b.
Fluid conduit 44 communicates fluid in the valve cartridge 20 with the second port 40. Fluid conduits 46, 47 communicate fluid in the valve cartridge 20 with the first port. An exhaust port 48 vents fluid pressure in the first port 33 to atmosphere 50 when the piston 14 is fully in the first piston direction 70a. The exhaust port 48 vents fluid in the second port when the piston is fully in the second piston direction 70b.
An actuator handle 18, when depressed, opens inlet valve 55 and permits air passage from the air inlet 16 to a main supply air passage 56. The main supply air passage 56 is in fluid communication with a first circumferential recess 58 formed in the valve cartridge 20 or alternatively in fluid communication with a circumferential recess formed in the housing bore.
A first diaphragm cavity orifice 60 and a second diaphragm cavity orifice both communicate the first circumferential recess 58 with the diaphragm cavity 26. The diaphragm 24 will tend to be biased in a first diaphragm direction 63a by application of fluid through the first diaphragm cavity orifice 60, which pressurizes a first cavity portion 61. The diaphragm 24 will tend to be biased in a second diaphragm direction 63b by application of fluid through a second diaphragm cavity orifice 62, which pressurizes a second cavity portion 64.
Since the first cavity portion 61 has a greater area of contact with the diaphragm than the second cavity portion, application of equal pressures to the first cavity portion 61 and the second cavity portion 64 will displace the diaphragm toward the second cavity portion 64, or generally in the second diaphragm direction 63b.
An actuator fastener 66 which retains the actuator handle 18 relative to the percussive apparatus 10 also passes through bolt aperture 68 formed in the valve cartridge 20. This arrangement restricts travel of the valve cartridge 20 relative to the housing 12 without the mating threads or alternative locking device between a piston valve and housing of the prior art percussion apparatus.
The operation of the present percussion apparatus 10 with the valve cartridge 20 is as follows. The piston 14 is typically displaced in the second piston direction 70b, due to gravity, when operation of the percussion apparatus begins. When the operator presses the actuator handle 18, depressing the inlet valve 55, permitting fluid communication between the air inlet 16 and the first circumferential recess 58.
Fluid applied to the first circumferential recess will pass through the first diaphragm cavity orifice 60 and the second diaphragm cavity orifice 62 to the first cavity portion 61 and the second cavity portion 64, respectively. Fluid in the first cavity portion 61 is applied to a greater surface area of the diaphragm than fluid applied in the second diaphragm portion. Also, any fluid passing though diaphragm port 80, into the second port 40 will exhaust through the exhaust port 48 (when the piston 14 is displaced fully in the second piston direction 70b) to prevent build up of fluid pressure in the second port.
Fluid passing from the first cavity portion 61 through a fluid conduit 82, a second circumferential recess 84, fluid conduits 46, 47 and first port 33 are closed off from the atmosphere when the piston is in the second piston direction 70b. Therefore, this pressure will add to the pressure contained in the first cavity portion in displacing the diaphragm in the first diaphragm direction 63a.
When the diaphragm is displaced in the first diaphragm direction 63a and the piston 14 is in the second piston direction, the fluid pressure will increase in conduits 82, 84, 46, 47 and first port 33. This increased pressure in the first port 33, combined with the second port 40 being in communication with the atmosphere through exhaust port 48, will result in displacement of the piston 14 in the first piston direction 70a.
The piston will accelerate in the first direction until the second port is closed off from the exhaust port 48. At this point, the momentum of the piston will compress the fluid contained in the second port, and the pressure in the second port will continually increase as the piston travels in the first piston direction 70a.
As the first piston surface 36 passes the exhaust port 48, the pressure in the first port 33 is vented to the atmosphere 50. The fluid pressure in fluid conduits 47, 46, 84, and 82 will also drop. Eventually, the total force applied from pressurized fluid contained in diaphragm port 80 and the second diaphragm portion 64 will be greater than the total force applied from pressurized fluid contained in diaphragm port 86 and the first diaphragm cavity 26. At this time, the diaphragm will displace in the second diaphragm direction 63b.
When the diaphragm is displaced in the second diaphragm direction 63b, as illustrated in FIG. 3, passage between the main supply air passage 32 and the first port 33 will be restricted. However, fluid will be able to pass between the main supply air passage and the second port 40. This supply of fluid pressure to the second port 40 will displace the piston 14 in the second piston direction 70b.
Momentum of the piston carries the piston in the second piston direction 70b until the second piston surface 42 passes the exhaust port 48. At this point, any remaining fluid pressure in the second port 40 will be exhausted to atmosphere.
Pressure will continue to be applied between the main supply air passage 56 and the second port 40 until the total air force in the diaphragm port 8 and the first diaphragm cavity 26 applied to the diaphragm 24 exceed the total air force in the diaphragm port 80 and the second cavity portion 64 applied to the diaphragm 24. At this point, the diaphragm is displaced in the first diaphragm direction, and fluid pressure from the main supply air passage 56 is once again applied to the first port.
The piston 14 and the diaphragm 24 continue the above described cycle until the operator releases the actuator handle 18, at which point the fluid pressure in the main supply air passage drops to atmospheric and the piston travels as far as it can in the second piston direction under the force of gravity.
While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that other variations and changes may be made therein without departing from the invention as set forth in the claims.
|
A piston valve diaphragm for a percussion apparatus including a valve portion having a diaphragm bore and a fluid supply source. A piston having a first piston surface and a second piston surface are also included. A diaphragm is mounted in the diaphragm bore and is displaceable in a first direction which permits fluid communication between the fluid supply source and the first piston surface and limits fluid passage between the fluid supply source and the second piston surface. Displacement of the diaphragm in a second direction permits fluid communication between the fluid supply source and the second piston surface and limits fluid passage between the fluid supply and the first piston surface. The diaphragm may be formed entirely from a flexible material or may contain a rigid center portion with flexible edge portion.
| 5
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 61/781,489 that was filed on Mar. 14, 2013, the entirety of which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to a computerized method for facilitating the trading of a future linked to the yield of at least one synthetic corporate bond benchmark.
BACKGROUND OF THE INVENTION
[0003] There are a wide variety of financial derivatives currently available in market. One type of derivative is a financial futures contract. Futures contracts derive their value in part from the value or characteristic of some other underlying asset. The underlying asset may include securities such as stocks, commodities, market indicators or indexes, interest rates, and government bonds, to name but a few of the most common assets.
[0004] In a futures contract a buyer purchases the right to receive delivery of an underlying commodity or asset on a specified date in the future. Conversely, a seller agrees to deliver the commodity or asset to an agreed location on the specified date. Futures contracts originally developed in the trade of agricultural commodities, but quickly spread to other commodities as well and today the majority of futures trading is in financial futures. Because futures contracts establish a price for the underlying commodity in advance of the date on which the commodity must be delivered, subsequent changes in the price of the underlying asset will inure to the benefit of one party and to the detriment of the other. If the price rises above the futures price, the seller is obligated to deliver the commodity at the lower agreed upon price. The buyer may then resell the received product at the higher market price to realize a profit. The seller in effect loses the difference between the futures contract price and the market price on the date the goods are delivered. Conversely if the price of the underlying commodity falls below the futures price, the seller can obtain the commodity at the lower market price for delivery to the buyer while retaining the higher futures price. In this case the seller realizes a profit in the amount of the difference between the current market price on the delivery date and the futures contract price. The buyer realizes an equivalent loss.
[0005] Futures contracts may be settled in cash. Rather than actually delivering the underlying asset, cash settlement merely requires payment of the difference between the market price of the underlying commodity or asset on the delivery date and the price at which the futures contract trade was executed. The difference between the market price and the futures price is to be paid by the short investor to the long investor, or by the long investor to the short investor, depending on which direction the market price has moved. Cash settlement provides great flexibility regarding the types of underlying assets that derivative investment instruments may be built around. Essentially any variable whose value is subject to change over time, may serve as the underlying asset for a derivative investment instrument.
[0006] Corporate bonds form part of the financing sources for modern companies, together with equity, bank loans, and structured financing products. The value of a security such as a corporate bond is based on its face value, the maturity date of the bond, coupon rate and frequency of coupon payments, and the creditworthiness of the issuer. A coupon payment on a corporate bond is a periodic interest payment that the bondholder receives during the time from bond issuance to maturity.
[0007] For example a 6% coupon for a bond with a notional value of one million US dollars would result in a payment amount of approximately (0.06)×(1,000,000) or $60,000, or a semi-annual payment of approximately $30,000 depending on the payment frequency and the day count basis of the interest payments. The amount that a buyer pays for such a bond depends on the yield at which it is offered. If the yield is below the coupon amount the bond will trade at a price greater than 100 (par) and vice versa. The yield is set by supply and demand but is typically set as a spread to the risk free US government bond yield. This spread fluctuates depending on many factors but primarily it reflects the additional credit risk of the corporation issuing the bond and tends to increase as the risk of default increases and or the maturity date of the bond. Rating agencies such as Moody's Investor Services, S&P and Fitch seek to quantify this risk of default by issuing credit rating schedules. The rating schemes followed by the three major rating services are all similar. Each includes multiple levels, with each level representing a different level of risk, or a different ranking of the perceived ability of a rated entity to meet its debt obligations. A 1 to 3-letter code identifies each of the different levels. For example Moody's defines nine primary risk levels: Aaa, Aa, A, Baa, Ba, B, Caa, Ca, and C. According to this system, the Aaa rating is reserved for the entities that demonstrate the strongest credit worthiness while those rated C demonstrate the weakest credit. There may also be a smaller additional risk premiums one example being an increase in yield if the bond is very illiquid.
[0008] According to the Securities Industry and Financials Markets Association (SIFMA) the size of the US corporate bond market in Q3 2012 was $8.6 trillion. SIFMA have recently reported quarterly traded volumes to be in the region of $21.1 billion per day in February 2013 with just 46,696 trades daily on average, and while some estimates place the number of corporate bond issues at around 40,000, TRACE reports about 6,500 issues trading per day. In contrast the US equity market has approximately 6,500 listings, daily volume in the region of $112 billion, 25 million trades and a market cap of $17 trillion. The Department of the Treasury, Office of Debt Management Fiscal Year 2012 Q2 Report cites that trading in 37 credits accounted for 50% of the trading volume in the corporate bond market. Clearly, the liquidity available with respect to equities is not available to a market participant wishing to buy or sell a corporate bond.
[0009] Unlike the equity market one corporation may issue several bonds but will typically have one major equity listing, this phenomena leads to sharply lower liquidity in the corporate bond market and wide bid offer spreads. The Department of the Treasury, Office of Debt Management Fiscal Year 2012 Q2 Report cites the average bid/offer spread on an Investment Grade bond was about 13 basis points in September 2011 and estimated that the transactional costs of trades can comprise 5% of the total security yield.
[0010] The majority of corporate bonds trade in the over the counter (OTC) market where prices and liquidity have traditionally been supplied by Wall Street Investment Banks. However recent changes in banks capital requirements and regulatory changes such as Dodd-Frank incorporating the ‘Volcker Rule’ restrictions on proprietary trading have required investment banks to drastically cut their inventory of corporate bonds. The Department of the Treasury, Office of Debt Management Fiscal Year 2012 Q2 Report states that dealer inventory has declined by more than 70% at a time when the total corporate bond issuance has been growing. As a result liquidity in the corporate bond market is provided by new dealers outside of investment banking institutions. The dealers provide electronic bids and offers to electronic bond trading platforms. These new dealers lack the financial resources of the investment banks and would benefit enormously from the existence of a liquid hedging instrument.
[0011] Investors generally consider factors such as credit markets as a whole, for example, that a change in economic activity or interest rates will cause corporate bonds to underperform versus government debt, or that one credit sector will outperform another. However trading based on these criteria in today's markets is costly if not impossible given the fragmented liquidity, wide bid/offer spreads and lack of availability of any liquid benchmark instruments.
[0012] Credit Default Swaps have been proposed as a solution to this dilemma. However, the complexity of this financial instrument and the present state of flux between OTC trading to exchange trading and clearing may make trading corporate bonds based on the Credit Default Swaps an undesirable option for the average investor or market maker in corporate bonds.
[0013] There are two principal designs of bond futures contracts in use today, a) contracts that require physical delivery of bonds on expiry of the contract, such as the contract on US treasury notes traded on the CME, and similar contracts on other government bonds traded at LIFFE (UK), EUREX (Frankfurt), TSE (Tokyo) and b) cash settled contracts the sole example of which is traded on the ASX (Sydney) linked to Australian Government Bonds. The complexity of the pricing and delivery mechanisms makes these types of contracts unsuitable for adaptation to corporate bonds for which no contracts are traded today.
[0014] The physical delivery model defines a basket of bonds at the time listing of the contract that can be used to satisfy the seller's obligation. Usually there is one bond that is the cheapest to deliver at expiry (CTD) for the seller and delivery activity is concentrated around the issue of this cheaper bond. The existence of a CTD bond can lead to situations where speculators try to create a shortage of the CTD to force the seller to deliver more expensive bonds and thus reap a higher profit. This speculation in government bonds has been observed in the United States treasury market, one of the most liquid government bond markets in the world.
[0015] Clearly, such a physical delivery model for corporate bonds would be fraught with difficulties in view of the illiquid corporate bond markets. An additional level of complexity to consider when studying the possibility of applying this model to the corporate bond market is that the credit risk on the existing contracts comprises of one homogenous credit i.e., one government risk. Applying CTD futures to the corporate bond market and a basket of several credits could result in the distortion of the market not just for one bond but for one corporation thus having some severe repercussions for the borrowing costs of that one corporation as well as other corporations.
[0016] The cash settled government bond contract traded on the ASX is linked to a basket of three or four Australian Government bonds selected by the exchange prior to the time of listing. There is no physical delivery. The exchange has a sophisticated method of determining the final futures settlement yield by calling dealers at three intervals and after discarding outlier quotes will calculate the average quoted yields for cash bonds. The ASX contract is quoted and traded in terms of yield (100−yield). For purposes of settlement, including the final settlement, the yield is converted into a bond price. While trading differently from the US government bonds contract, the contract actually settles in a similar manner, on price. This cash settlement methodology avoids the complexities of the cheapest to deliver as seen in the US government bond contracts. However, the calculations of settlement prices and trading revenues remains complex and the value or a price move is variable depending on the yield traded.
SUMMARY OF THE INVENTION
[0017] In view of recent changes with respect to the ability of investment bankers to trade corporate bonds and the lack of liquidity of the corporate bond market, there is a need to develop a computerized method which facilitates cash corporate bond trading by offering a liquid method of hedging by providing the trading of futures contracts linked to synthetic corporate bond benchmark yields. Preferred embodiments of the invention provide a computerized method that facilitates the trading of a future linked to the yield of at least one synthetic corporate bond benchmark.
[0018] In a computerized method for facilitating the trading of a future linked to at least one synthetic corporate bond benchmark yield in accordance with the invention a series of futures contracts is listed on an electronic exchange platform. The futures contract includes terms that require settlement in cash upon expiry of the contract on the specified date based on at least one synthetic corporate bond benchmark yield. An electronic exchange platform, or a computer receives one or more orders to buy or sell a futures contract. An order book of such orders to buy or sell futures contracts is built via a computer process and the orders are matched according to pre-defined matching rules. An order to buy or sell the futures contract linked to at least one synthetic corporate bond benchmark yield is executed. Pricing information including unattributed pricing data of the futures contracts, i.e., prices and quantities in the book and executed trades are disseminated to market participants and executed trade data is electronically transmitted to a clearing house. A synthetic corporate bond benchmark yield determined by the reference data source is electronically transmitted to the electronic exchange platform and market participants
[0019] In one embodiment the synthetic corporate bond benchmark is defined by a combination of as many or as few of the following attributes as is desirable at the listing of the contract before trading commences: Maturity (tenor), credit rating, industry, currency, country of domicile or other such terms that represent economic value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] To provide a more complete understanding of the present invention and features and advantages thereof, there is illustrated in the accompanying diagrams an embodiment thereof, which when considered in connection with the following description, many of its advantages should be readily understood and appreciated.
[0021] FIG. 1 depicts an overview of a simplified block diagram illustrating a schematic of a system for facilitating the trading of a synthetic corporate bond benchmark futures contract in accordance with an embodiment of the present invention;
[0022] FIG. 2 depicts a diagram illustrating an example of a synthetic corporate bond benchmark futures contract that may be traded on the system illustrated in FIG. 1 in accordance with an embodiment of the present invention;
[0023] FIG. 3 depicts a diagram illustrating an example of a synthetic corporate bond benchmark futures spread contract that may be traded on the system illustrated in FIG. 1 in accordance with an embodiment of the present invention;
[0024] FIG. 4 depicts a diagram illustrating an example of hedging ratios of cash corporate bonds with an embodiment of the futures contract, and an illustration of the rate of change of the value of a basis point in yield; and
[0025] FIG. 5 depicts an overview of a simplified flowchart illustrating a series of example steps with a method which may be taken by an exchange providing a futures contract in FIGS. 2 and 3 using the system illustrated in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] The method of the invention provides that a futures contract which relates only to corporate bonds is settled upon expiry with reference to a published yield for a synthetic corporate bond benchmark, within a defined industry, maturity, credit rating, currency or country of domicile or a combination of any of these features or other features having an economic impact. Linking the future to a synthetic security and cash settling on the same avoids the complexities of the physical delivery model and may facilitate liquidity in the corporate bond cash markets without introducing potentially harmful Cheapest to Deliver and associated potential manipulative practices and pressures.
[0027] The futures contract will have a fixed dollar value for every incremental change in yield thus avoiding the complexities of existing bond contracts with respect to yield and price conversion observed in present contracts.
[0028] Features of some embodiments of the invention will now be described by first referring to FIG. 1 . FIG. 1 depicts an overview of a simplified block diagram illustrating a schematic of a system 100 for facilitating trading of the futures contract 200 . The system 100 comprises; a buyer 101 , a seller 103 , a broker 105 , communications network 110 , an exchange platform 120 , a reference data source 140 and a clearing house 150 . The exchange platform 120 may include a processor 122 , a listing utility 124 , a matching engine and order book 126 , a reporting utility 128 , a market data dissemination utility 130 and a settlement calculation engine 135 . The exchange platform 120 may be coupled to a clearing house 150 .
[0029] The exchange platform 120 is a trading architecture that facilitates the purchase and sale of one or more futures contracts 200 . The exchange platform is operable to receive and process requests relating to trading orders in the futures contract 200 . The exchange platform 120 may be owned and operated by a suitable entity having the authority to operate a futures exchange and will be comprised of one or more computers operated by that entity. The exchange platform may operate generally along conventional practices, except for the embodiments disclosed herein and may list and facilitate trading in other futures and options contracts in addition to the novel contracts described herein. As will be appreciated by those who are skilled in the art, the futures trading exchange 120 may perform functions normally performed by a trading exchange, such as listing contracts for trading, receiving and matching orders to buy and sell the listed contracts, providing current quotations and reports concerning open orders and trading activity on the exchange 120 .
[0030] Clients 101 and 103 wishing to buy and sell the futures contract 200 will maintain accounts with brokers 105 who are exchange members, clients 101 / 103 will electronically transmit orders to their broker 105 for onward transmission to the exchange platform 120 via the communications network 110 . In addition or alternatively the brokers/trading firms 105 may place orders for their own account with the futures trading exchange 120 .
[0031] The communications network 110 is a communicative platform operable to exchange data or information between buyer 101 , the seller 103 , the brokers 105 and exchange platform 120 . In one embodiment of the invention the communications network 110 represents an Internet based architecture. Alternatively, it could be any communications network which buyer 101 , Seller 103 or brokers 105 could use to perform the same operations or functions. In other embodiments, communications system 110 could be any packet data network (PDN) offering a communications interface or exchange between any two nodes in the system 100 . Communications network 110 may alternatively be any local area network (LAN), metropolitan area network (MAN), wide area network (WAN), wireless local area network (WLAN), virtual private network (VPN), intranet, or any other appropriate architecture or system that facilitates communications in a network or telephonic environment.
[0032] The end user interface employed by either buyer 101 , seller 103 or broker 105 in order to initiate transactions or to perform monitoring functions within system 100 may be the users proprietary software, or broker or third party vendor provided software and could be software presently used to facilitate trading in existing futures contracts modified where necessary to facilitate the futures contract 200 . Alternatively, such an end user interface may be replaced with any other suitable interface or object that facilitates communications between buyer 101 , seller 103 , broker 105 , and any other element within system 100 , such as: a cellular telephone, a laptop, a smartphone, touchpad, or any other suitable device (wireless or otherwise), component, or element capable of accessing one or more elements within system 100 . The end user interface may also comprise any suitable interface for a human user such as a display, a microphone, a keyboard, or any other appropriate terminal equipment according to particular configurations and arrangements.
[0033] The exchange platform 120 may comprise of any appropriate information storage device, including combinations of magnetic storage devices (e.g., magnetic tape and hard disk drives), optical storage devices, and/or semiconductor memory devices such as Random Access Memory (RAM) devices and Read Only Memory (ROM) devices. In some embodiments the hardware aspects of this system component may be entirely conventional.
[0034] The exchange platform 120 comprises of one or more programs (at least some of which being shown by blocks 124 - 135 ) for controlling processor 122 . Processor 122 performs instructions of the programs, and thereby operates the exchange platform 120 in accordance with the present invention. The listing utility 124 is able to list one or more futures contracts 200 for trading by the exchange platform 120 .
[0035] Another program, the matching engine/order book 126 allows the exchange platform 120 to receive and process incoming instructions including orders to buy and sell futures contracts 200 , to match offsetting orders in accordance with the exchange matching engine rules and maintain a book of pending orders after being properly managed and secured by processor 122 . The matching engine 126 may operate in accordance with conventional practices.
[0036] Another program, the reporting utility portrayed by block 128 provides reports of activity on the exchange platform 120 allows for orderly settlement of trades executed on the exchange platform 120 , and also provides reports as needed for compliance with regulatory requirements.
[0037] Exchange platform 120 may also deliver real-time data to market participants and market data vendors, the data dissemination utility 130 handles this function. The data dissemination utility 130 may disseminate pertinent information such as the time, quantity of contracts and price of executed trades, outstanding bids and offers i.e. the current state of the order book to be used by market participants and cash corporate bond traders to make decisions as to whether to purchase or to sell futures contract 200 . It may also disseminate data, such as contract information, contract spread information e.g. the difference between two or more futures contracts, settlement prices, historical quotes, or moving averages. Where possible this program will operate along conventional lines in order to facilitate integration into present trading interfaces. The potential integration of this data into dealers electronic pricing and quoting engines for cash bonds is important to facilitate the use of futures contract 200 as a reference mechanism enabling greater liquidity in the cash bond markets.
[0038] The settlement method 224 at expiry of the futures contract 200 is set by use of the yield of the synthetic corporate bond benchmark 201 according to the reference data source 140 . In one embodiment of the invention this source may be the Bloomberg Valuation Service. The settlement calculation engine 130 maps the reference data source to the appropriate futures contract 200 and in accordance with the settlement method 224 calculates the final settlement value of trades as the difference between the traded price and the settlement price adjusted for the tick value and number of contracts traded.
[0039] Another component of the system 100 is a clearing house 150 . The clearing house 150 acts as counterparty with respect to all traders or investors who buy or sell the futures contract 200 in the traditional manner.
[0040] Another component of the system 100 is a reference data source 140 . The reference data source 140 may provide data to either or both of the exchange platform 120 and the clearing house 150 . For example, a potential source of a yield for a synthetic corporate bond benchmark 201 may be obtained from the “Bloomberg Valuation Service (BVAL)” who provides such data on a daily basis. Bloomberg Valuation Service calculates the yields of these synthetic corporate bond benchmarks 201 by reference to the observed trading activity in relevant individual corporate cash bonds using a sophisticated proprietary algorithm that weights bonds by liquidity, excludes outliers caused by technical trading factors and excludes certain bond structures. Bloomberg publishes more than 50 investment grade sector curves across various rating levels each of which is constructed by calculating points for various tenors or maturities. Bloomberg weights the observed trading activity in an individual corporate bond in the basket of corporate bonds by the tenor to calculate a theoretical yield for a synthetic corporate bond benchmark of a fixed tenor assuming that bond were issued today. For example, the yield of a corporate bond with a maturity of 10.5 years would be given a higher weight than the yield of a bond with an 8 year maturity if one were calculating the yield of a synthetic 10 year bond in the Bloomberg calculation. Based on these calculations Bloomberg determines a yield for a new synthetic bond based on the yields of a basket of selected corporate bonds.
[0041] Any suitable reference benchmark yield based on calculating the yield of a synthetic corporate bond benchmark may be used in the invention provided that the calculation is based upon observed underlying activity in the corporate cash bond market and therefore is a good representation of the true underlying market, thus linking the futures contract to observable activity in cash markets. The tie to actual published rates reflective of the cash market is very important for two reasons a) to avoid arbitrary rate setting as was reported recently with respect to LIBOR rates, and b) to avoid the necessity of physical delivery with all the complications and weaknesses associated with CTD mechanisms discussed above.
[0042] Importantly, the recently implemented FINMA TRACE reporting requirement for corporate bond trades provides the transparency required to calculate a benchmark yield with some accuracy. The TRACE reporting requirement requires that trades in corporate bonds are reported to a central authority within 15 minutes of execution. This is a stringent regulatory requirement. Trades are published and generally publicly available.
[0043] FIG. 2 depicts an overview of one embodiment of a corporate bond future and blocks 201 through 205 demonstrate how a synthetic corporate bond benchmark 201 may be defined given a set of desirable economic variables to be reflected in the value of the futures contract 200 . The yield of the synthetic corporate bond benchmark 201 will be calculated by the reference data source 140 using cash bonds that have been mapped by the reference data source 140 to the criteria provided that they meet the proprietary standards set for inclusion in the calculation as discussed above. The synthetic corporate bond benchmark 201 criteria may be selected by reference to whether the criteria would capture a wide enough pool of cash bonds for calculation of a yield for the synthetic corporate bond benchmark 201 . For example, were there only a small number of corporate bonds issued by corporations mapped to the industry Financials Consumer Credit then this industry may be subsumed into the broader industry of Financials. The currency 201 maybe set as any currency in which underlying cash corporate bonds are issued. The Tenor 203 in one embodiment may be 5 years, 7 years, 10 years and 30 years with other tenors being made available if required. The credit rating 204 in one embodiment refers to values assigned to a corporate bond by one of Moody's Investor Services, Standard and Poor's or Fitch. The industry 205 definitions available for use in the contract 200 may be determined by the reference data source 140 as described above and in one embodiment these may represent the industries used by FINMA in TRACE reporting.
[0044] The futures contract expiry months 210 in one embodiment will be quarterly and defined as March, June, September and December in line with a well-established practice in the financial futures market. In another embodiment there will be two expiries listed at any one time for each contract synthetic corporate bond benchmark 201 . The contract listing date 212 is the first date that the futures contract 200 is available for trading on the system 100 .
[0045] The futures contract 200 , in accordance with the invention, will provide for price quotation 214 , the daily settlement price and the settlement method 224 to be in terms of yield to maturity on a percent per annum basis, quoted on the basis of (100−yield), e.g. a bid at a yield of 4.95% shall be entered into the system 100 at a price of 95.05. In one embodiment the minimum price movement 216 shall be quoted in 0.005 increments or one half of a basis point, e.g. if another buyer 101 wished to enter a better bid than the existing bid of 4.95% the next permissible price would be 95.055 representing a yield of 4.945%. In other embodiments futures contract 200 may set the minimum price movement 216 in smaller increments. Each minimum price increment 216 will represent a pre-determined currency amount fixed for the life of the futures contract 200 this is known as the minimum price value 217 .
[0046] The minimum price value 217 set prior to the listing of the contract remains constant throughout the life of the futures contract 200 irrespective of the yield/price levels quoted or traded. This simplification greatly assists the speed of trading decisions, there being no conversion price/yield calculations to be effected and no cheapest to deliver security to track. By setting the minimum price increment value to a constant for each contract it becomes very simple to move exposure from one industry to another by simply buying one contract and selling the other. In one embodiment the last trading day 218 may be set as the third Wednesday of the expiry month, providing that this is a good business day for trading cash corporate bonds. In such embodiment, trading shall cease at 5 μm EST in the US or 5 μm local time for the relevant currency 201 , or whatever time the cash corporate bond market closes on the last trading day 218 . Daily trading hours 222 for the futures contract 200 on the exchange platform 120 may match the trading hours of the underlying cash corporate bond market, with such trading hours 222 being established and published prior to the listing date 212 .
[0047] The settlement date 220 shall be the next available business day following the last trading day 218 in the currency 202 in which the futures contract 200 is denominated. Settlement will be effected by a cash payment or receipt to or from the clearing house 150 as calculated in accordance with the settlement method 224 as the difference between the trade price and the synthetic corporate bond benchmark supplied by the reference rate source 140 multiplied by the number of contracts traded. This settlement methodology simplifies settlement value determination in that does not require any conversions of yield to bond price, accrued interest considerations or cheapest to deliver conversion factors.
[0048] The advantages accruing to participants in the corporate bond market, whether dealers or investors by the availability of the futures contract 200 facilitated by the system 100 may be better understood by considering the following examples. The advantages or the futures contract are in no way limited to the instances described, which are stated here merely for the purposes of illustration on how the futures contract 200 may be used for practical benefit by participants in the corporate bond market.
Example 1
[0049] Corporate bond yields are typically composed of two main components, the risk free rate which is the rate at which US treasuries trade plus a credit spread which is the risk premium that an investor receives for lending to a credit other than the US government. This credit premium may increase as the risk of default increases. There may also be additional smaller premiums one example being an increase in yield if the bond is very illiquid. The futures contract 200 seeks to allow a participant in the corporate bond market to hedge a cash bond position against a general industry wide move in the credit spread relative to the risk free rate. An example of how the futures contract 200 may effect this is described below.
[0050] An bondholder owns a corporate bond with a nominal value of one million US dollars issued by XYZ automobile corporation, the bond having a credit rating ‘A’, a 7 year maturity, and a semi-annual coupon of 5.00% The bond last traded at a price of 118.12% implying a yield to maturity of 2.9% per annum (p.a) using standard calculation methodologies. The bond has a dollar value (DV01) of $676 which means that a one basis point increase in yield will change the value of the bond by $676. As shown in FIG. 4 , the value of a basis point change is not a constant and will change with a change in yield. The basis point value also changes with time as the tenor of the bond shortens.
[0051] The bondholder believes that there will be negative economic news that will affect all corporations in the industry to which his/her bond issuer belongs. An example of such news maybe that demand for new cars is going to fall due to tighter credit criteria and therefore car companies are going to be less profitable and possibly incur losses which in turn will increase risk premiums (spreads) for the bonds. It is the view of the bondholder that yields will rise by at least 40 basis points.
[0052] In the absence of the present invention, the bondholder has four choices:
Sell the bond and buy it back later. As the bid/offer spread on corporate bonds may be 10 basis points even for more liquid issues this is an expensive option. If the bond is less liquid the bondholder may not be able to locate a buyer at all. Hold the bond and accept the loss. Sell another similar bond on which there is an advantageous bid and will change value approximately in line with the present holding, then reverse the position later once the expected spread move has occurred. The bondholder will of course need to borrow the bond in the repo market, which may be difficult, and of course the bid offer spread may have to be crossed to buy back the bond sold such that the bondholder is back to option one. Sell US treasuries. This option will not work as the risk the bondholder anticipates is a shift in credit spreads due to an economic change and a scenario where corporate bonds underperform US treasuries.
[0057] Invariably, in the absence of the present invention, the bondholder will take no action. The corporate bond markets will continue to be illiquid and the risk of losing investment capital as shown above is simply accepted.
[0058] The present invention will provide the bondholder with another option, sell a futures contract 200 linked to the same industry, maturity and credit rating as the bond held. The futures contract 200 may act as a central liquidity marketplace for hedging all corporate bonds in the industry and therefore the futures contract 200 trades on a tighter bid/offer spread. Furthermore selling the future will avoid the necessity of borrowing a bond in the repo market.
[0059] In this hypothetical example, the futures contract 200 has a minimum price value 217 of $33.75 per ½ basis point and the bond at the present yield 405 has a DV01 410 of $676. With reference to FIG. 4 , the hedge ratio may therefore be calculated as 676/(33.75*2) giving a hedge ratio 420 of 10.01 contracts. As the futures contract 200 trades in round numbers the bondholder will sell 10 contracts.
[0060] If the bondholder is correct in his/her prediction, bond yields rise by 40 basis points and at a yield of 3.30% p.a. the bond in question is now worth approximately 110.55% of notional, using standard yield to maturity calculations, and the bondholder will sustain a loss of $26,693. The futures contract 200 may show a profit of 27,000 (10*80*33.75) being number of contracts, number of half basis points, and minimum price value 217 . Assuming that both the futures contract 200 and the bond move by the same number of basis points the resultant loss between the bond and the future is $306, which represents approximately ½ a basis point in yield of the bond ( 306 / 676 ), clearly a beneficial outcome for the bondholder and far better than any of the initial three options outlined above. This ‘drift’ occurs mainly due to the fact that the bond DV01 401 is not a constant like the minimum price value 217 of the futures contract 200 and that the bond DV01 401 will in fact change as the yield changes as shown in FIG. 4 .
[0061] The risk to the bondholder is that the corporate bond yield being hedged moves by a different amount than the benchmark bond reference rate 201 . This may happen if the perception of the riskiness of the corporation in question differs from that of the overall industry, in which case these moves may easily be greater than the loss due to the ‘drift’ on the hedge. The loss on the hedge, when taken into consideration against residual credit spread risks, cash bid/offer spreads and illiquidity is a relatively small number and therefore this loss may be disregarded as ‘noise’.
[0062] The performance of the futures contract 200 would be unacceptable to a holder of government bonds where the credit is homogeneous, the bid/offer spread on the cash bonds may be as low as 0.2 basis points and there are no liquidity concerns. Thus government bond futures need to be more complex to offer a more precise hedge. In contrast the present invention provides a computerized method for facilitating futures trading of corporate bonds which does not rely on complex considerations.
[0063] As will be understood by a person skilled in the art of futures trading, the futures contract 200 will not necessarily trade or be quoted at the same price/yield as the yield of the underlying synthetic corporate bond benchmark prior to expiry of the futures contract. Convergence is only forced in the settlement method 224 at expiry of the futures contract 200 .
Example 2
[0064] A dealer seeks to generate a profit by buying and selling bonds and capturing the bid offer spread. The dealer seeks returns commensurate with the risk involved in the activity and where markets are liquid and risk is easy to enter and exit, the bid/offer spread will be narrower than a market where liquidity is ‘thin’ and trading happens infrequently. A dealer who seeks such a return in the cash corporate bond market may have to hold a position for some time.
[0065] A dealer owning a corporate bond has limited ability to hedge credit spread risk and thus quotes a wide price, or doesn't quote at all and thus the illiquidity continues. The most obvious option for a dealer who buys a bond is simply to hold it until a buyer is located however long that may be. In the meantime the credit spread may move but hopefully the dealer has sufficient profit in the price at which he purchased the bond and this adverse move will still leave the dealer with a profit at the end of the day.
[0066] The futures contract 200 may offer the dealer a source of liquidity to hedge credit spread risk for an industry. For example, a dealer when he buys a bond issued by an investment bank may turn round and sell the futures contract 200 with a synthetic corporate bond benchmark 201 linked to the Financials industry 205 . The dealer may locate a buyer for the bond a few days later, sells the bond and buys the future. The existence of the future as a liquid hedge may mean that the dealer can wait for a more advantageous price on the cash bond thus capturing more of the initial bond bid/offer spread. The ability to capture more of the spread will mean that the dealer may quote tighter prices in the first place and attract more business with less risk. As other dealers use the futures contract 200 to hedge their bond trades in the industry 205 the futures contract 200 gains liquidity and thus trades in many individual bonds become one central pool of liquidity. The role of futures contract 200 may be pivotal in providing the central source of liquidity that facilitates tighter bid/offer spreads in cash bonds. This in turn by attracting more investors to the corporate bond market may increase liquidity and lower spreads, and thereby may reduce the cost at which corporations can raise cash.
Example 3
[0067] An investor or money manager may have various views and opinions on the potential value in one industry versus another. For example, an investor may believe that corporate bonds in the health care industry will outperform those in the financial industry and therefore he wishes to gain exposure to the difference in yield between the two industries.
[0068] One way to execute on this view at the present time is to buy bonds in the health care industry while selling those in the financial industry. A person practiced in the art of bond trading will appreciate the complexities of assembling offsetting portfolios of bonds of the same duration, bpv/dv01 and convexity, not to mention the difficulties of borrowing the bonds shorted in the repo market. Alternatives to this option may be to assemble the trade using credit default swaps or the investor may call an investment bank and enter into a tailor made transaction. However these alternatives may have liquidity implications that the investor is not willing to assume.
[0069] In another alternative in accordance with the present invention, the investor may buy a futures contract 200 with a contract synthetic corporate bond benchmark 201 linked to the healthcare industry 205 , and the investor may form a view about which tenor 202 , and/or rating 204 would be most advantageous to use. The ‘long position’ may be offset by selling a futures contract 200 with a synthetic corporate bond benchmark 201 linked to the financials industry 205 with a similar tenor 203 and rating 204 as the health care industry future. The minimum price movement 216 and the minimum price valuation 217 may be the same on both contracts, thus simplifying the execution of the trade i.e., the investor buys and sells the same number of contracts of each future.
[0070] A hypothetical example illustrating this embodiment of the invention is set forth below.
[0071] Given a market quoted below the investor will ‘open’ a position by buying healthcare at 96.32 and selling financials at 97.30.
[0000]
Futures Prices
Implied Yields p.a.
Financials
97.30
97.32
2.70
2.68
Health Care
96.30
96.32
3.70
3.68
[0072] At a later time the market may be quoted as below and the investor ‘closes’ the position by selling healthcare at 97.50 and buying financials at 98.02. The investor realizes a profit of $3,105 (where “bp” means basis points).
[0000]
Prices
Yields
Financials
98.00
98.02
2.00
1.98
Health Care
97.50
97.51
2.50
2.49
Healthcare
1
96.32
−1
97.50
by move 118.00* 67.50 =
$7,965.00
Financials
−1
97.30
1
98.02
by move 72.00* 67.50 =
−$4,860.00
Net Profit/(loss)
$3,105.00
[0073] While the general level of yields changed on both contracts, the investor was trading a view on the relative value and has simply and effectively captured that change by use of the futures contracts 200 on the relevant synthetic corporate bond benchmarks and has been insulated from general movement in interest rates. The constant nature of the minimum price value 217 reduces the complexities associated with attempting to replicate the same exposure in the cash corporate bond market.
[0074] FIG. 3 illustrates another embodiment of a futures contract 200 where the contract synthetic corporate bond benchmark 301 is constructed to capture the change in the difference in yields between two individual synthetic corporate bond benchmarks linked to different industries 305 . In this embodiment the minimum price movement 316 and the minimum price value 317 may be the same as the futures contracts 200 with contract synthetic corporate bond benchmarks 201 linked to individual synthetic corporate bond benchmarks or industries 205 . The price quotation 314 is the number of basis points difference between the two underlying futures price quotations. In this example for the contract synthetic corporate bond benchmark 301 Financials/Healthcare Spread the price quotation 414 is 98/102.
[0000]
Futures Prices
Implied Yields p.a.
Financials
97.30
97.32
2.70
2.68
Health Care
96.30
96.32
3.70
3.68
Spreads
0.98
1.02
where buy Financials sell Health Care = 102
sell Financials buy Health Care = 98
[0075] In one embodiment a futures spread contract 300 may be settled as two individual trades. In another embodiment the futures spread contract 300 may be settled as one trade.
[0076] FIG. 5 depicts an overview of a simplified flow chart that illustrates a process that may be performed by a futures trading exchange using the system 100 . In FIG. 5 , block 502 , the futures exchange lists one or more futures contracts 200 that are cash settled by the clearing house 150 relative to the settlement method 224 . In further embodiments, the listing of futures contracts may (in addition to or alternatively) include spread contracts 300 and option on futures contracts 200 and 300 .
[0077] In FIG. 5 , block 504 , the buyer 101 , seller 103 and brokers 105 submit orders and requests to the exchange platform 120 via the communications network 110 . The exchange platform 120 receives an order to buy one of the futures contracts listed at 502 and stored in the listing utility 124 or an order to sell one of the futures contracts listed at 502 . The order may include some or all of the order parameter data detailed in the contract specification 200 or 300 . On receiving the order, the exchange platform 120 may time-stamp the order and store it, including the order parameter data, and build a book of orders block 506 . At FIG. 5 , block 508 the matching engine and order book 128 matches buy orders with sell orders with respect to each listed futures contract 200 or 300 . This may be done in accordance with conventional practices and may be ongoing during the trading day as orders are received
[0078] At 510 in FIG. 5 , the exchange platform 120 provides reports of trades executed and orders placed in the order book(s) for the listed futures contract(s). This reporting may, among other functions, be disseminated to market participants and data vendors by the data dissemination processor 130 and become a source of market quotations for potential traders. Moreover, the reporting may be such as required to comply with regulatory policies and the internal requirements of the futures trading exchange.
[0079] At 512 in FIG. 5 , the exchange platform 120 performs conventional functions required for overnight processing and to facilitate settlement of trades executed during the trading day.
[0080] As one skilled in the art will appreciate embodiments of the invention provide many desirable and beneficial features, including but not limited to:
(1) the invention provides that futures contract shall be cash settled avoiding the necessity of physical delivery and concerns about liquidity and availability of cheapest to deliver corporate bonds, (2) the invention provides a simple calculation of profit and loss arising from a position by assigning a constant currency value to a minimum incremental change in yield, (3) the invention provides a clear and easy method to ascertain the yield being traded by quoting the price terms of the contract as 100 minus yield, (4) the invention provides a novel method of trading and hedging portfolios of corporate bonds, (5) the invention offers investors an instrument to trade which is a combination of both credit spread and risk free rate exposure in one contract, (6) the invention offers an investor an instrument to trade the relative yields of one industry versus another through the combination of two futures contracts, or in another embodiment the trading of such relative yields through the offering of one contract linked to the yield differential, (7) the invention offers an investor an instrument to trade the yield curve within an industry by the combination of two futures contracts, (8) the invention offers an investor an instrument to trade an option on the futures contact, (9) the invention will facilitate increased liquidity and tighter bid/offer spreads in the corporate bond cash market by the creation of a liquid hedge instrument, and (10) the invention will provide wider access to the corporate bond market through the establishment of a standardized exchange traded instrument linked to the performance of a synthetic corporate bond benchmark.
[0091] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention.
|
A method of creating and trading on an exchange a futures contract linked to the yield of synthetic corporate debt instruments. The terms of the contract are such that it provides for a cash payment from one party to another based on the yield of a synthetically created corporate bond benchmark upon expiration of the futures contract. The synthetic corporate bond benchmark terms may include a combination of yield, credit rating, maturity, industry, currency or some other economically significant variable such terms being defined prior to the standardized contract being available for trading. Corporate synthetic benchmarks are valued by assigning traded corporate debt securities to the defined risk category and calculating the resultant yield. The contract may also reference two or more synthetic benchmarks.
| 6
|
BACKGROUND OF THE INVENTION
The present application is a continuation in part of utility patent application Ser. No. 07/666,702, filed Mar. 8, 1991, which application is incorporated herein.
FIELD OF THE INVENTION
The present invention relates to a paving block assembly and paving blocks for forming the paving block assembly.
DESCRIPTION OF THE RELATED ART
Paving blocks are interconnected to, for example, form pathways or roadways. A majority of the force applied against the paving blocks is usually applied against the top. However, the paving blocks are often subjected to force in the lateral direction. This force can be applied by pedestrian or vehicular acceleration, deceleration, or turning. When the paving blocks are positioned on a grade, the acceleration of gravity can also generate a force on the paving blocks in the lateral direction. The force applied in the lateral direction due to the force of gravity can become especially significant when the paving blocks are in position for a long period of time and subjected to vibration.
When lateral forces are applied to a paving block, the paving block transmits the forces to adjacent paving blocks at a point or points of contact between the paving blocks. The ability of the adjacent paving blocks to resist lateral forces determines the paving block assembly's ability to remain stabilized and intact.
When a paving block has a flat or planar side surface, the transmission of a lateral force by the paving block and corresponding resistance to the force by an adjacent paving block occur along the flat side surface of the paving block When loads are applied along a flat side surface, the paving block or the adjacent paving block may crack due to point loading or stress caused by rotational forces A crack diminishes the paving block's ability to resist forces applied against it. A crack in the paving block also increases the paving block's susceptibility to damage caused by water and freeze/thaw cycles. Such damage causes the paving blocks to deteriorate and decreases their effective life span.
A paving block having a flat side surface can also cause the force transmission and corresponding resistance to occur at a corner of the paving block. When force transmission occurs at a corner, the corner is sometimes crushed, thereby reducing the paving block's ability to resist forces. The crushed corner can also increase the paving block's vulnerability to damage due to water and freeze/thaw cycles.
SUMMARY OF THE INVENTION
An object of the invention is to provide paving blocks which are able to transmit and resist lateral forces without the problems encountered by previous paving blocks.
Another object of the invention is to provide paving blocks which have improved effective life spans over previous paving blocks.
Another object of the invention is to provide a paving block assembly having improved lateral stability over previous paving block assemblies.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a first paving block a top surface, a bottom surface, and side surfaces extending between the top surface and the bottom surface. The side surfaces include first and second substantially concave side surfaces, a third substantially concave side surface positioned on a first side of the paving block between the first and second concave side surfaces, and a substantially convex side surface positioned between the first and second concave side surfaces on a second side of the paving block which is opposite the first side.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention also comprises a substantially symmetrical second paving block having a line of symmetry. The second paving block includes a top surface, a bottom surface, and side surfaces extending between the top surface and the bottom surface. The side surfaces include first and second substantially convex side surfaces, the length of an arc defined by the first convex side surface being substantially equal to the length of an arc defined by the second convex side surface, the first convex side surface being disposed on a first side of the line of symmetry and the second convex side surface being disposed on a second side of the line of symmetry, and first and second substantially concave side surfaces positioned between the first and second convex side surfaces, a radius of curvature of an arc defined by the first concave side surface being substantially equal to a radius of curvature of an arc defined by the second concave side surface, and the first concave side surface being disposed on the first side of the line of symmetry and the second concave side surface being disposed on the second side of the line of symmetry.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises an assembly of the above described paving blocks, the paving blocks being interconnected to form a continuous surface, the assembly including at least one repeating unit having two adjacent first paving blocks and two substantially symmetrical second paving blocks. The first concave side surface of one of the first paving blocks contacts the second convex side surface of one of the adjacent second paving blocks, the second concave side surface of the one first paving block contacts the first convex side surface of the other adjacent second paving block, and the convex side surface of the one first paving blocks contacts the third concave side surface of the other adjacent first paving block.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention also comprises an assembly of paving blocks interconnected to form a continuous surface, the assembly including at least one symmetrical first paving block and at least two second paving blocks positioned adjacent the first paving block on opposite sides of the line of symmetry, the first and second paving blocks having respective curved surfaces contacting side surfaces for forming an arched interconnection between the one first paving block and the two second paving blocks, wherein a force applied along the line of symmetry of the first paving block is bifurcated and resisted by the second paving blocks.
The paving block assembly of the present invention improves over previous paving block assemblies by, among other things, reducing damage to paving blocks caused by the transmission of lateral forces. This advantage is achieved by, for example, transmitting lateral forces along curved surfaces, as opposed to flat surfaces, by forming the side surfaces of the paving blocks in arc shapes.
Additionally, the paving blocks of the present invention can be combined to form a paving block assembly having an arch shape. The arch shaped paving block assembly distributes lateral forces to a plurality of adjacent paving blocks. The distribution of force increases the lateral stability of the paving block assembly and can decrease the force which must be borne by each of the individual paving blocks. By decreasing the force borne by each of the individual paving blocks, the possibility of damage to the blocks can be decreased.
Both of the above mentioned features of the present invention improve the lateral stability of the paving block assembly and increase the life span of the paving blocks by reducing damage thereto However, the above is not an exhaustive list of the advantages of the present invention.
For example, the paving blocks of the present invention allow for easy insertion of filler material by providing spacers on the side surfaces of the paving blocks Filler material can be inserted into a gap between the paving blocks, which is provided by the spacers. The spacers are positioned such that their presence is not noticeable when the filler material has been inserted. Furthermore, the spacers improve the uniformity of spacing between the blocks.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a preferred embodiment of the paving block assembly of the present invention;
FIG. 2 is a top plan view of a preferred embodiment of a first paving block of the paving block assembly;
FIG. 3 is a front elevational view of the first paving block;
FIG. 4 is a side elevational view of the first paving block;
FIG. 5 is a rear elevational view of the first paving block;
FIG. 6 is a top plan view of a preferred embodiment of a second paving block of the paving block assembly;
FIG. 7 is a front elevational view of the second paving block;
FIG. 8 is a side elevational view of the second paving block.
FIG. 9 is a rear elevational view of the second paving block; and
FIG. 10 is top plan view of the paving block assembly of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
In accordance with the invention, the paving block assembly 20 of the present invention includes two paving blocks of a first kind and two paving blocks of a second kind. As embodied herein, and with initial reference to FIG. 1, assembly 20 includes a plurality of first paving blocks 30 and a plurality of second paving blocks 50. The first paving blocks 30 and second paving blocks 50 can be positioned as shown in FIGS. 1 and 10 to form a continuous paved surface. As can be seen in FIG. 1, a combination of two first paving blocks 30 and two second paving blocks 50 provides a geometrical shape which is similar to the shape of a first paving block 30 and forms a common repeating unit. As show in FIG. 10, this unit can be repeated to form the paving surface
Further in accordance with the present invention, the paving block of the first kind comprises a top surface, a bottom surface, and side surfaces extending between the top surface and the bottom surface The side surfaces include first, second, and third substantially concave side surfaces and a substantially convex side surface.
As embodied herein, the first paving block 30 is illustrated in FIGS. 1-5. The first paving block 30 includes a top surface 31, a bottom surface 32, and side surfaces extending between the top surface 31 and the bottom surface 32. Preferably, the first paving block 30 is symmetrical about a line of symmetry A. The top surface 31 and bottom surface 32 are preferably planar. The side surfaces are disposed at right angles to the top surface 31 and the bottom surface 32.
Preferably, the first paving block 30 has at least four side surfaces. In a more preferred embodiment, the first paving block 30 has six side surfaces.
As shown in FIG. 2, the first paving block 30 has a first substantially concave side surface 33 and a second substantially concave side surface 34. Preferably, the length of the arcs defined by the first concave side surface 33 and the second concave side surface 34 are equal. Additionally, the radius of curvature of the arc defined by the first concave side surface 33 is equal to the radius of curvature of the arc defined by the second concave side surface 34.
A third substantially concave side surface 35 is also provided on the first paving block 30. The third concave side surface 35 is positioned between the first concave side surface 33 and the second concave side surface 34. In a preferred embodiment, the third concave side surface 35 is bisected into a first concave minor side surface 35A and a second concave minor side surface 35B. By bisecting the third concave side surface 35, a furrow 38 is formed. This furrow 38 aids in the positioning of first paving blocks 30 relative to one another. The first concave minor side surface 35A and the second concave minor side surface 35B preferably have equal arc lengths and radii of curvature.
The first paving block 30 also has a substantially convex side surface 39. The convex side surface 39 is positioned between the first concave side surface 33 and the second concave side surface 34. In a preferred embodiment, the convex side surface 39 is bisected into a first convex minor side surface 39A and a second convex minor side surface 39B. The bisection of the convex side surface 39 creates a ridge 42. The ridge 42 can be inserted into the furrow 38 of an adjacent first paving block 30 to position the first paving blocks 30 relative to one another. The length of the arc defined by the first convex minor side surface 39A is preferably equal to the length of the arc defined by the second convex minor side surface 39B. The radii of curvature of the first convex minor side surface 39A and the second convex minor side surface 39B are also equal.
In the above described preferred embodiment, the first concave side surface 33, first concave minor side surface 35A, and first convex minor side surface 39A are disposed on a first side of the line of symmetry A. The second concave side surface 34, second concave minor side surface 35B, and second convex minor side surface 39B are disposed on a second side of the line of symmetry A.
A beveled edge 43 can be formed at the intersection of the top surface 31 and the side surfaces. When the first paving block 30 has a beveled edge 43, the first paving block 30 is bilaterally symmetrical, i.e., only one plane can divide the first paving block 30 into identical halves. In a preferred embodiment, this plane must be normal to the top surface 31 and pass through the line of symmetry A.
In a particularly preferred embodiment of the first paving block 30, the radii of curvature of all the side surfaces are equal. A preferred radius of curvature is 211.25 millimeters. In the particularly preferred embodiment, the overall length of the first paving block is 205.54 millimeters, the length of a chord extending between the end points of the convex side surface 39 is 195.00 millimeters, and the length of a chord extending between the end points of the third concave side surface is 65.00 millimeters.
Additionally, spacers 44 can be provided on the side surfaces of the first paving block 30 to position the first paving blocks 30 relative to adjacent paving blocks. The spacers 44 also aid in assembly of the paving blocks by providing a gap for inserting filler material between the paving blocks. The spacers 44 are preferably an integral part of the first paving block 30 and have a rounded surface. Preferably, the spacers 44 are formed substantially in the shape of approximately one half of an elongated cylinder with a rounded top portion.
In a preferred embodiment, the spacers 44 are disposed on the first convex minor side surface 39A and the second convex minor side surface 39B. Preferably, three spacers are positioned on each of the first convex minor side surface 39A and the second convex minor side surface 39B. The spacers 44 disposed on each convex minor side surface are preferably positioned approximately 40 millimeters apart.
As shown in FIG. 3, the spacers 44 preferably extend only part of the distance between the bottom surface 32 and the top surface 31. Preferably, the spacers 44 begin at the bottom surface 32 and extend approximately five sixths of the distance between the bottom surface 32 and the top surface 31. The spacers 44 are thereby capable of adequately spacing adjacent paving blocks, yet the spacers 44 are not visible when filler material is placed between the paving blocks.
Further in accordance with the present invention, the paving block of the second kind comprises a top surface, a bottom surface, and side surfaces extending between the top surface and the bottom surface. The side surfaces include first and second substantially convex side surfaces and first and second substantially concave side surfaces.
As embodied herein, the second paving block 50 is shown in FIGS. 1 and 6-9. Preferably, the second paving block 50 is symmetrical about a line of symmetry B. The second paving block 50 includes a top surface 51, a bottom surface 52, and side surfaces extending between the top surface 51 and the bottom surface 52. The top surface 51 and bottom surface 52 are preferably planar. The side surfaces are disposed at right angles to the top surface 51 and the bottom surface 52.
Preferably, the second paving block 50 has four side surfaces. As shown in FIG. 6, the second paving block 50 has a first substantially concave side surface 53 and a second substantially concave side surface 54. The length of the arcs defined by the first concave side surface 53 and the second concave side surface 54 are equal. Additionally, the radii of curvature of the arcs defined by the first concave side surface 53 and the second concave side surface 54 are also equal.
The second paving block 50 also has a first substantially convex side surface 55 and a second substantially convex side surface 56. The first convex side surface 55 and the second convex side surface 56 are positioned between the first concave side surface 53 and the second concave side surface 54. The length of the arc defined by the first convex side surface 55 is preferably equal to the length of the arc defined by the second convex side surface 56. The radii of curvature of the arcs defined by the first convex side surface 55 and the second convex side surface 56 are also equal.
The first concave side surface 53 and first convex side surface 55 are disposed on a first side of the line of symmetry B. The second concave side surface 54 and second convex side surface 56 are disposed on a second side of the line of symmetry B.
A beveled edge 57 can be formed at the intersection of the top surface 51 and the side surfaces. When the second paving block 50 has a beveled edge 57, the second paving block 50 is bilaterally symmetrical. In a preferred embodiment of the second paving block 50, as with the first paving block 30, the plane must be normal to the top surface 51 and pass through the line of symmetry B.
Additionally, spacers 58 can be provided on the side surfaces of the second paving block 50 to position the second paving blocks 50 relative to adjacent paving blocks. The spacers 58 are preferably an integral part of the second paving block 50 and have a rounded surface. Preferably, the spacers 44 are formed substantially in the shape of approximately one half of an elongated cylinder with a rounded top portion.
In a preferred embodiment, the spacers 58 are disposed on the first convex side surface 55 and the second convex side surface 56. Preferably, two spacers are positioned on each of the first convex side surface 55 and the second convex side surface 56. The spacers 58 disposed on each convex side surface are preferably positioned approximately 120 millimeters apart.
As shown in FIG. 7, the spacers 58 preferably extend only part of the distance between the bottom surface 52 and the top surface 51. Preferably, the spacers 58 begin at the bottom surface 52 and extend approximately five sixths of the distance between the bottom surface 52 and the top surface 51. The spacers 58 are similar to the spacers 44 in that they separate adjacent paving blocks and are not noticeable when filler material is placed between the paving blocks.
In a particularly preferred embodiment of the second paving block 50, the radii of curvature of all the side surfaces are equal. A preferred radius of curvature is 211.25 millimeters. In the particularly preferred embodiment, the overall length of the second paving block is 195.00 millimeters and the width is 130.00 millimeters.
In a preferred embodiment, the radii of curvature of all of the side surfaces of both the first paving block 30 and the second paving block 50 are equal. However, this is not required to practice the invention. The radii of curvature of the side surfaces of the paving blocks which contact corresponding side surfaces of adjacent paving blocks, should be equal to the radii of curvature of the corresponding side surfaces to ensure a proper fit.
FIG. 10 illustrates the arch effect of the paving block assembly 20 of the present invention. An arch is formed by the first paving block 300, the second paving block 500, the first paving block 310, the second paving block 510, and the first paving block 320. The arch effect is achieved, in part, because the length of a chord extending between the end points of an arc defined by the convex side surface 39 is larger than the chord length of the arc defined by the third concave side surface 35.
If the first paving block 330 and the two second paving blocks 520, 530 are removed, the arch would maintain the integrity of the paving block assembly 20 against any lateral force applied against the convex side surface 39 of the first paving block 310. The first paving block 310 is the keystone in a traditional arch. As the lateral force is applied to the first paving block 310, it bifurcates the force and transmits lateral forces to the two adjacent second paving blocks 500, 510. Each of the two adjacent second paving blocks 500, 510 bifurcates the lateral force transmitted to them and in turn exert a lateral force on the adjacent first paving blocks 300, 330 and 330, 320, respectively. As in a traditional arch, none of the pieces can fall out because of their shapes and the combination of horizontal and vertical loads being applied.
The paving block assembly 20 of the present invention is not intended to be used with the first paving block 330 or second paving blocks 520, 530 removed. However, the fact that these paving blocks can be removed and the stability of the paving block assembly 20 can still be maintained, demonstrates one of the advantages of the present invention.
FIG. 10 also illustrates the benefits of transferring force across a curved surface. The load from one paving block is always transferred to other paving blocks along a segment of the curved surface and never at a point. For example, a load applied against the convex side surface 39 of the first paving block 310 would be resisted by the first paving block 330 and the two second paving blocks 500, 510. Likewise, if a lateral force is applied against the third concave side surface 35 of the first paving block 330, the force would be resisted by the first paving block 310 and the two second paving blocks 500, 510.
Similar force distribution exists when a lateral force is applied against the first or second concave side surfaces 33, 34 of the first paving block 310, as well as in any of these directions on the second paving block.
A paving block can be subjected to a rotating force. A rotating force can be generated when, for example, a wheel of an automobile is turned. The resistance of the paving block assembly 20 of the present invention is more complex, but the paving block assembly 20 resists the force in a similar manner. For example, a clockwise force applied to the first paving block 330 would be resisted by all of the adjacent paving blocks. The loads are transferred to adjacent blocks along segments of the curved side surfaces, in such a manner as to resist cracking or crushing of the paving blocks.
In all cases, a lateral force is transferred along curved surfaces, which distributes the force. Any lateral force applied to a first or second paving block is resisted by at least three other paving blocks. By distributing the force, the ability of the paving blocks to resist cracking and crushing is increased.
The paving assembly 20 of the present invention solves these load force transmission problems by, among other things, distributing the force across an arch and transferring forces from one paving block to another along a curved joint. Both of these features improve the lateral stability of the paving system and reduce damage to the paving blocks.
Additionally, as shown in FIG. 10, the spacers 44, 58 are positioned on the side surfaces of the paving blocks such that each paving block is separated from each adjacent paving block by at least two spacers. For example, the first paving block 310 is contacted by two spacers positioned on each of the first paving block 330, the second paving block 500, and the second paving block 510. Similarly, at least two of the six spacers on the first paving block 530 contact each of the second paving block 500, the first paving block 310, and the second paving block 510. Separating adjacent paving blocks by at least two spacers improves the accuracy of the positioning of the paving blocks. Moreover, the provision of multiple, evenly distributed spacers enhances the force distribution characteristics of the assembly, discussed above.
Furthermore, because in the preferred embodiment the spacers 44, 58 are positioned only on the convex surfaces of the paving blocks, there is no concern that the paving blocks will be improperly laid with the spacers of a paving block engaging or interfering with the spacers of an adjacent paving block. A convex surface of a paving block, which has spacers, will always mate with a concave surface of an adjacent paving block, which does not have spacers. Additionally, the ease of laying the paving block assembly is increased because the paving blocks need not be examined prior to laying to determine if they will properly mate.
The placement of spacers on the convex surface has additional advantages. For example, spacers on a convex surface cover a greater surface area of the convex surface than the same spacers would on a concave surface, thereby providing a broader base for the spacers and greater stability.
It will be apparent to those skilled in the art that various modifications and variations can be made in the paving blocks and paving block assembly of the present invention and without departing from the scope or spirit of the invention.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
|
A paving block assembly and first and second paving blocks therefor. The first and second paving blocks are combined to form a continuous paving surface. Spacers are provided on the blocks for assuring, among other things, correct positioning of the blocks in a continuous paving surface. The paving blocks have concave and convex curved side surfaces, which increase the durability of the paving blocks. The paving blocks in the paving block assembly form an arch shaped pattern, which increases the stability of the paving block assembly.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2008 023 709.4, filed May 15, 2008; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an apparatus and a method for the correct phase engagement of rotatably drivable mechanically coupled components in printing material processing machines, in which at least two rotatably drivable components can be connected mechanically through a coupling.
In particular, in sheet-fed rotary printing presses, impression cylinders, sheet transport cylinders, plate cylinders and blanket cylinders as well as inking units and dampening units are mechanically coupled in printing units through gearwheel trains. The mechanical coupling of the individual components in the printing units of the printing press is important in printing operation, in order to permit printing with accurate register. Accurate register means that firstly individual color separations are printed exactly above one another and secondly the color separations are printed with a corresponding relative position with respect to an edge of a printed sheet. However, that rigid mechanical coupling during printing operation has disadvantages if a print job change is imminent. During the print job change, rubber blankets have to be washed in the printing units on the blanket cylinders. Moreover, the inks usually have to be changed in the inking units. Furthermore, the rigid mechanical coupling makes the change of the printing plates more difficult during the job change. For that reason, a change has been made to constructing sheet-fed rotary printing presses which, although they are coupled mechanically during printing operation, have a mechanical coupling which can be canceled for the print job change, with the result that individual cylinders and components in the printing press can be driven independently of one another and a plurality of operations can run in parallel independently of one another.
A sheet-fed rotary printing press of that type is known from European Patent Application EP 0 834 398 A1, corresponding to U.S. Pat. No. 5,983,793. In that sheet-fed rotary printing press, the plate cylinders in the printing units can be decoupled in each case from the blanket cylinders. To that end, there is a coupling which can be opened and closed in each printing unit between the plate cylinder and the blanket cylinder. In that way, the mechanical gearwheel train including the transport cylinder and the blanket cylinder can be operated independently of the plate cylinders. In each printing unit, there is a drive motor, by way of which the plate cylinder can be driven independently. In printing operation, however, the couplings are closed and the entire gear train with all of the cylinders in all of the printing units is driven through a main drive motor. The inking units and dampening units are coupled fixedly in each case to the plate cylinders, with the result that the angular positions of the rollers in the inking unit and the dampening unit do not change with respect to the angular positions of the plate cylinders. In order to couple the plate cylinders including the inking unit and the dampening unit into the gearwheel train with the other cylinders again, they have to be positioned in a defined relative position with respect to one another. If that relative position is not correct, the printing quality becomes unusable. For that purpose and in order to position the channels of the adjacent blanket cylinder and plate cylinder correctly with respect to one another, the couplings in the printing units between the plate cylinder and the blanket cylinder are configured as index couplings which make engagement possible in a correspondingly provided position. When that position is reached, the coupling closes and the plate cylinders are again engaged in correct phase with respect to the remaining cylinders.
Furthermore, European Patent Application EP 0 978 378 A2, corresponding to U.S. Pat. No. 6,758,141, has disclosed a method and a device for obtaining an ink profile which is close to continuous printing in the inking unit of a sheet-fed offset printing press. It is possible in that case to decouple the inking unit rollers from the plate cylinder through the use of a double gearwheel which is configured as a coupling. As a result, it is possible for the inking unit to be brought to a standstill while all of the other cylinders, such as plate cylinders, blanket cylinders, impression cylinders and sheet transport cylinders, can rotate independently. As a result of the standstill of the inking unit, idling of the inking unit can be avoided if the printing press is set in operation in a delayed manner. Engagement in correct phase of the inking unit to a defined position of the plate cylinder is provided in order to reengage the inking unit to the drive gear train with the other cylinders.
However, the prior art does not take different rotational speeds of rollers and cylinders in the printing unit of a printing press into consideration. The inking unit rollers and plate or impression cylinders thus usually have different rotational speeds in operation due to gear mechanism transmission ratios. If engagement in correct phase is to take place over the rotating components with different transmission ratios, there is the problem that some components rotate, for example, twice through 360 degrees during the same time that others rotate only once through 360 degrees. That means that the relative angular position of the component which rotates twice as fast with respect to another component which rotates at single speed is not clear over a revolution because one component with a revolution in comparison with the other component passes through an angular position twice. That problem can lead to not all of the rotating components being reengaged into the gearwheel train in their preferential position in correct phase.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method for engagement in correct phase of mechanically coupled components which can be driven rotatably and are operated at different rotational speeds in a transmission ratio in a mechanically coupled state or cylinders with different revolution rates, as well as a sheet-fed rotary printing press having the mechanically coupled components or cylinders, which overcome the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for correct phase engagement of rotatably drivable mechanically coupled components in printing material processing machines. The method comprises mechanically coupling at least two of the rotatably drivable components through a coupling, operating the at least two rotatably drivable components at different rotational speeds in a transmission ratio in a mechanically coupled state, accessing the transmission ratio with a control computer for controlling an engagement operation, and taking the transmission ratio into consideration during the correct phase engagement.
With the objects of the invention in view, there is also provided a sheet-fed rotary printing press, comprising rotatably drivable rollers and cylinders, at least one of the rollers and at least one of the cylinders being drivable at different rotational speeds in a transmission ratio during operation of the printing press, at least one coupling for mechanically coupling the cylinders and rollers, and a control computer accessing the transmission ratio for controlling an engagement operation and taking the transmission ratio into consideration during correct phase engagement.
The method according to the invention and the apparatus according to the invention are suitable, in particular, for use in sheet-fed rotary printing presses. As has already been stated, sheet-fed rotary printing presses have plate cylinders, blanket cylinders and impression cylinders in every printing unit. In addition, there are transport cylinders such as transfer cylinders and turning drums between the printing units. The transport cylinders transport the sheet-shaped printing materials from one printing unit to the next. Furthermore, the printing units have inking units with inking unit rollers which are coupled with different transmission ratios to the cylinders in the printing unit. The different transmission ratios bring about a situation where cylinders and inking unit rollers do not operate at the same rotational speed. However, the relative angular positions of the rollers and cylinders with different transmission ratios are therefore not clear with respect to one another. If, for example, a roller rotates two or three times, the adjacent cylinder rotates only once. According to the present invention, there is then provision for the transmission ratio to be taken into consideration or account during the engagement in correct phase in the case of at least two components which can be driven rotatably. To this end, a control computer of the printing press has access to the respective transmission ratio of the participating components which can be driven rotatably and takes this transmission ratio into consideration during the engagement in correct phase by orienting the cylinders and rollers correspondingly with respect to one another through drive motors and then engaging in correct phase. The corresponding transmission ratios, such as rotational speeds in the ratio 1:2 or 1:3, are often called half-revolution or third-revolution. It is thus possible that some inking unit rollers have half the transmission ratio in comparison with the plate cylinder, while other rollers or the ink ductor have a third of the transmission ratio. This relationship of the inking unit rollers and the ink ductor can not only refer, however, to the plate cylinder, but it can equally well refer to the impression cylinder or other cylinders in the gearwheel train. In most cases, a coupling will be provided which is provided between the plate cylinder and an inking unit roller or between the plate cylinder and the blanket cylinder. Through the use of this switchable coupling, the inking unit rollers and the ink ductor can be decoupled from the plate cylinder and/or blanket cylinder and from the impression cylinder which is coupled to the plate cylinder and/or blanket cylinder.
However, it goes without saying that it is also possible for a plurality of couplings to be provided in a printing unit. For example, an additional coupling can thus be provided between the plate cylinder and the blanket cylinder or between the blanket cylinder and the impression cylinder. The gearwheel train which connects the printing units and has the transport cylinders can also be disengaged by couplings.
A very wide variety of coupling and drive structures is conceivable by way of the cylinders and inking unit rollers such as distributors and ink ductors, and also by way of correspondingly disposed couplings between cylinders and inking unit rollers and/or ink ductors. Each part which can be decoupled preferably has an electric drive motor, by way of which decoupled components can be driven rotatably in an independent manner. In this case, the sheet transport cylinders, such as impression cylinders, transport cylinders and turning drums, are preferably driven jointly by the main drive motor of the printing press. In order to make engagement in correct phase possible, the decoupled drive trains have to be positioned in correct phase with respect to one another through the use of the drive motors, which is monitored and performed by the control computer. To this end, the couplings can be actuated electrically and can be opened and closed by the control computer.
In accordance with another mode of the invention, at least two of the components which can be driven rotatably have sensors for detecting the angular position. In order to permit correct phase engagement of components which can be driven rotatably with different revolution rates, sensors are provided on the components which can be driven rotatably. The relative angular positions of the components which can be driven rotatably with respect to one another can be detected by way of the sensors. The angular sensors can be configured as absolute rotary encoders, with the result that the angular position can also be determined clearly over a plurality of revolutions. The angular position can therefore also be detected and stored exactly at any time for components which can be driven rotatably at half the revolution rate or a third of the revolution rate or other transmission ratios. When the components which can be driven rotatably are reengaged, the components can then be positioned by the drive motors according to the previously stored angular positions and can then be reengaged in correct phase.
It is also possible to use inductive sensors in the rollers with a lower-revolution transmission ratio. The inductive sensors generate a pulse in each case per revolution. The pulse is then processed further by the machine controller. In this way, the sensors generate a clear signal change once per revolution, which signal change is then evaluated together with the values of an incremental encoder, for example, on a single-revolution plate cylinder. This results in a ⅙ th revolution resultant rotating frequency in the case of a third-revolution ink ductor circulation and a half-revolution distributor circulation in relation to the single-revolution plate cylinder. It is also possible in this way to reengage in correct phase components which can be driven rotatably with different transmission ratios.
Each drive train which can be decoupled preferably has at least one angle sensor, by way of which an absolute angular position or relative angular position with respect to a reference component can be determined. All of the sensors are connected to the control computer, in order for it to be possible to control the coupling operation. It is also possible to bring about engagement in correct phase over a plurality of printing units. In this case, the relative angular positions of cylinders and rollers are compared with one another over a plurality of printing units, with the result that cylinders and rollers with different revolution rates can also be engaged in correct phase over a plurality of printing units.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for engagement of cylinders with different revolution rates in correct phase and a sheet-fed rotary printing press having the cylinders, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a fragmentary, diagrammatic, longitudinal-sectional view of a sheet-fed rotary printing press having two printing units; and
FIG. 2 is a diagram showing a phase profile of a third-revolution ink ductor and a half-revolution distributor roller in relation to a single-revolution plate cylinder.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a printing press 1 which represents merely one example of a sheet-fed rotary printing press. The invention is independent of the number of printing units, as a result of which two printing units 5 are shown herein, only by way of example. In principle, the printing units 5 are of identical construction, with each printing unit 5 having a plate cylinder 7 , a blanket cylinder 6 and an impression cylinder 2 . The plate cylinder 7 carries a printing plate with a printing image, while the blanket cylinder 6 has a rubber blanket for transferring the printing image from the plate cylinder 7 onto the printing material. The printing material is printed in a press nip between the impression cylinder 2 and the blanket cylinder 6 . The sheet-shaped printing materials are transported by transport cylinders 3 and turning drums 4 from one printing unit 5 to the next printing unit 5 . Recto and verso printing on both sides of sheet-shaped printing materials is possible through the use of the turning drums 4 . All of the cylinders 2 , 3 , 4 , 6 , 7 are coupled mechanically to one another through non-illustrated gearwheels and are driven during printing operation through a common main drive motor 17 .
Furthermore, each printing unit 5 has an inking unit including distributor rollers 8 , 9 and an ink ductor 10 which removes the ink from a non-illustrated ink fountain. The ink ductor 10 and distributor rollers 8 , 9 are likewise connected mechanically to one another. This mechanical coupling takes place through a gear mechanism 15 , with the individual components having different transmission ratios than one another. The ink ductor 10 thus has a third-revolution construction, that is to say the plate cylinder 7 performs three revolutions when the ink ductor 10 performs one revolution. In contrast, the first distributor roller 8 has a transmission ratio causing it to rotate 3.85 times during one revolution of the plate cylinder 7 . In contrast, oscillating movements of the further distributor rollers 9 are of half-revolution, that is to say the plate cylinder 7 performs two revolutions when the half-revolution distributor roller 9 moves back and forth once. These transmission ratios result from the gear mechanism transmission ratio in the gear mechanism 15 . The ink ductor 10 and the rollers 8 , 9 , which are connected mechanically to one another in this way, can be coupled mechanically to the remaining cylinders 2 , 3 , 4 , 6 , 7 through a coupling 11 . A mechanical coupling action between the plate cylinder 7 and the blanket cylinder 6 is brought about through the electrically actuable coupling 11 . Since the other cylinders are coupled mechanically to the blanket cylinder 6 and the distributor rollers 9 , the plate cylinder 7 and the ink ductor 10 are coupled mechanically to the distributor roller 8 , closing the coupling 11 brings about complete mechanical coupling of all of the rollers, cylinders and the ink ductor 10 in the sheet-fed printing press 1 . As a result, all of the components which are driven rotatably in the printing units 5 are coupled mechanically to one another over the entire printing press 1 and are driven by the common main drive motor 17 during printing operation.
However, in the case of changeover operations between print jobs, it is appropriate to decouple the inking unit and the plate cylinder 7 from the other cylinders 6 , 2 , 3 , 4 through the use of the electrically actuable coupling 11 . As soon as the coupling 11 is open, the rollers 8 , 9 , the plate cylinder 7 and the ink ductor 10 can rotate with respect to the remaining cylinders 2 , 3 , 4 , 6 . If, however, the decoupled inking unit rollers 8 , 9 , the plate cylinder 7 and the ink ductor 10 are not reengaged in correct phase with respect to the blanket cylinder 6 or impression cylinder 2 before the printing operation, this results in an impairment of the printed image, since all of the rotating components have a preferential position with respect to one another due to tolerance fluctuations in production. The best print quality is delivered in that preferential position. A plurality of sensors 14 , which detect the angular position of the respective rotating component, are provided in the printing units in order for it to be possible for the position of the rotating components with respect to one another to be determined and for the engagement in correct phase to be controlled. In one embodiment, sensors 14 are at least provided on the plate cylinder 7 , on the ink ductor 10 and on the half-revolution oscillating distributor roller 9 . The sensors 14 on the half-revolution oscillating distributor roller 9 and on the third-revolution ink ductor 10 are configured as inductive sensors which generate one pulse per revolution in each case. In contrast, the sensor 14 of the plate cylinder 7 is configured as an incremental encoder. A control computer 12 , which can be a constituent part of the printing press 1 , detects a clear signal change per revolution of the inductive sensors of the half-revolution oscillating distributor roller 9 and the third-revolution ink ductor 10 and combines that signal with the values of the incremental encoder of the single-revolution plate cylinder 7 . In this case, a ⅙ th revolution resultant circulating frequency results in relation to the single-revolution impression cylinder 7 from the third-revolution ink ductor circulation and the half-revolution distributor circulation. Engagement in correct phase is possible through this circulating frequency, despite different transmission ratios. The signals of the sensors 14 are shown correspondingly in FIG. 2 . It can be seen therein that the plate cylinder 7 rotates twice during an oscillating movement of the half-revolution distributor roller 9 , and it rotates three times during one circulation of the third-revolution ink ductor 10 .
During the synchronous running of the inking unit and the sheet-guiding cylinders 2 , 3 , 4 , 6 , 7 in printing operation, the control computer 12 can detect the relative position of the individual rotating components with respect to one another through the resulting ⅙ th revolution circulating frequency. The detected relative positions are stored in the control computer 12 before leaving the synchronous running by opening the coupling 11 .
If the inking unit is to be reengaged into the gearwheel train of the cylinders 2 , 3 , 4 , 6 and washing operations and the plate change are concluded, the positions of the inking unit rollers 8 , 9 and of the inking unit ductor 10 as well as of the plate cylinder 7 need to be synchronized again to the gear train. In this case, the relative positions of the plate cylinder 7 , distributor rollers 9 and ink ductor 10 which are stored during synchronous running are called up. In this case, the components are positioned through the actuation of electric drive motors 16 on the plate cylinders 7 of the printing press 1 and the main drive motor 17 .
Instead of the plate cylinder 7 , another cylinder such as the impression cylinder 2 can also be selected as a reference cylinder. In this case, the impression cylinder 2 then has an incremental encoder. The control computer 12 can also equally well evaluate the relative positions with respect to one another over a plurality of printing units 5 . Instead of the combination shown herein of incremental encoders and inductive sensors, it goes without saying that it is also possible to embody all of the sensors 14 as incremental encoders which in each case detect corresponding angular positions. Incremental encoders can detect the positions clearly over a plurality of revolutions, as absolute value encoders. The sensors 14 and the drive motors 16 , 17 of the printing press 1 are connected to the control computer 12 of the printing press 1 through a communications link 13 . A drive for opening and closing the coupling 11 can likewise be actuated by the control computer 12 through the communications link 13 , with the result that fully automatic engagement in correct phase as a result of the control computer 12 is possible.
|
An apparatus and a method for correct phase engagement of mechanically coupled rotatably drivable components in printing material processing machines, include a coupling for mechanically connecting at least two of the rotatably drivable components. The at least two rotatably drivable components are operated at a different rotational speed in a transmission ratio in a mechanically coupled state, and a control computer has access to the transmission ratio for controlling an engagement operation and taking the transmission ratio into consideration during the correct phase engagement.
| 1
|
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to semiconductor devices of low and high voltage, vertically and laterally developed and to a combination of such devices on a single substrate. The present invention also relates to integrated injection logic combining low voltage devices, both laterally and vertically developed, which are in turn combined with high voltage devices, both laterally and vertically developed, with the latter, vertically developed devices, being associated, optimally, in a "Darlington" connection. The invention also relates to the method of making such combined devices.
2. Description of the Prior Art:
Vertically developed power transistors with the collectors down, and emitters up are conventional. Darlington connected power transistors, in which the collectors are formed lowermost, with the collectors sharing a common interconnecting region and common contacts are also conventional.
Such power devices are most commonly available in the NPN format using a substrate of N+ type material, upon which an N type epitaxial layer is formed. The NPN bases, of P material, are formed from the top, over the underlying N region, by a diffusing process. The NPN emitters are then formed over the bases. The final arrangement is a vertically developed transistor, having a first junction between collector and base and a second junction between base and emitter. Such vertical devices may be combined by a "Darlington" connection in which the emitter of one device is coupled to the base of the other device, and their collectors are connected together, by sharing the common, lower N region and a common substrate contact. It is also known that the devices may be conveniently driven by the addition of a laterally developed PNP transistor formed on the same substrate, which may be connected to the base of the "one" NPN.
Low voltage integrated injection logic (I 2 L) has been described in the literature, as for instance Hart, C. M. and Slob, A., "Integrated Injection Logic--A New Approach to LSI", 1972 IEEE International Solid State Circuits Conference Proceedings, pp 92-93, and Berger, H. H. and Wiedman, S. K., "Merged Transistor Logic--A Low Cost Bipolar Logic Concept", 1972 ISSCC Proceedings, pp. 90-91. In addition, certain practical devices using the I 2 L technique have been marketed by several semiconductor manufacturers.
The technique has several attractive features. One desirable feature of the technique is that the speed power product is very small, being demonstrated at less than 1.0 picojoules. In addition, because it can use conventional linear bipolar devices, the fabrication processes are conventional and manufacturing costs are relatively inexpensive.
The integrated injection logic, conventional integrated bipolar transistors are operated in an inverted mode. In I 2 L logic, NPN transistors, which consist of successive horizontal layers have their emitter lowermost, the base above the emitter, and the collector topmost, usually in separate islands within the base. The resultant multiple collector device is compact and, when supplied with an appropriate base biasing current source or "injector", constitutes a basic "NOR" type gate, building block. The "NOR" function results when the collectors of different multiple collector devices are connected together. The current source used to bias the base of the I 2 L multi-collector NPN transistors can be realized in many ways. The most popular I 2 L configuration uses a lateral PNP transistor as the base biasing source. Another elementary I 2 L function is that of simple inversion requiring a single collector, NPN and PNP base biasing source.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved integrated circuit combining low voltage and high voltage devices.
It is a further object of the present invention to provide an improved integrated circuit combining vertically and horizontally developed low voltage devices and vertically and horizontally developed high voltage devices.
It is still another object of the invention to provide an improved integrated circuit in which low voltage control logic is present to control power switching devices.
Accordingly, it is an additional object of the present invention to provide a simplified method of making an integrated circuit combining low voltage and high voltage devices.
It is a further object of the present invention to provide an improved method of making an integrated circuit combining vertically and horizontally developed low voltage devices and vertically and horizontally developed high voltage devices.
It is still another object of the invention to provide an improved method of making an integrated circuit in which low voltage control logic is present to control power switching devices.
These and other objects of the invention are achieved in a novel integrated circuit comprising a monolithic substrate having an underlying highly doped first region of a first conductivity type, and a second moderately doped region of the first conductivity type overlying the first region and epitaxially formed. Power transistor means are formed on the substrate, which include a first vertically developed power transistor, having a first underlying collector, defined in the second region, a first base of a second conductivity type, disposed upon the first collector, and a first emitter of the first conductivity type, disposed upon and horizontally bounded by a continuation of the base material. Means for control of the power transistor means are formed in the same substrate, including a second, vertically developed control transistor. The control transistor comprises a second, underlying emitter defined in the second region, a second base, of the second conductivity type, disposed upon the second emitter, and a second collector of the first conductivity type, disposed upon and horizontally bounded by a continuation of the second base material.
The control means also includes means for coupling the collector of the second vertically developed transistor to the base of the first vertically developed transistor. Preferably, the coupling means includes a lateral transistor comprising a third emitter of the second conductivity type, disposed upon the second region, a third base formed of an upwardly extending continuation of the second region, laterally adjacent to the third emitter, and a third collector of the second conductivity type disposed upon the second region, laterally adjacent to the third base and formed as a continuation of the first base material for electrical connection between said third collector and the first base.
In accordance with the invention, the first vertical power transistor and the third, lateral transistor are designed for high voltage operation and the second, vertical control transistor is designed for low voltage operation. To achieve these objectives, the emitter of the second vertical control transistor is of higher conductivity than the collector of the first, vertical power transistor. The base of the first, power transistor is thick in relation to the base of the second, control transistor. The base of the third, lateral transistor has a first region of a higher conductivity equal to that of the emitter of the second, vertical control transistor, and a second region of a lower conductivity equal to that of the collector of the first, vertical power transistor, to form a graded base for improved high voltage performance. In addition, the second region of the substrate has two layers, the lowermost layer being of a high conductivity type than the uppermost layer. Finally, a ring of the second conductivity type is formed around the power transistor means for further improving the high voltage performance.
In accordance with a further aspect of the invention, the power transistor means includes a fourth, vertical power transistor disposed for Darlington interconnection with the first, vertical power transistor.
The arrangement readily permits the addition of other vertical control transistors designed for low voltage operation, each having an emitter in the second region of the substrate for common connection between the emitter. Other horizontal control transistors for current injection into the vertical control transistor may be added. The collector of the current injector may be formed as a lateral continuation of the base of the vertical transistor.
In accordance with a further aspect of the invention, a method for making an integrated circuit of the type including low voltage and high voltage semiconductor devices on a single substrate is disclosed. A substrate is provided having an underlying highly doped first region of a first conductivity type, with a second moderately doped region of the first conductivity type overlying the first region. The doping level in a first volume is increased in respect to a second volume by ion implantation, the volumes extending down from the upper surface of the substrate into the second region. Next, one simultaneously diffuses an impurity of a second conductivity type with device patterning into the first and second volumes to produce a third, device patterned region overlying the second region having a depth in said first volume which differs from that in the second volume. Then, one simultaneously diffuses an impurity of the first conductivity type (with device patterning) into the first and second volumes to produce a fourth, device patterned region overlying the third region. The method produces vertically developed semiconductor devices in the first volume having a geometry differing from the devices in the second volume.
In accordance with a further aspect of the invention, the first diffusion may be patterned to form laterally developed semiconductor devices complementary to the vertically developed semiconductor devices. When the first diffusion patterns occur in the first volume, low voltage devices are formed complementary to the vertically developed semiconductor devices. When the first diffusion patterns occur in both volumes, a laterally developed semiconductor device having a graded base for improved performance may be formed.
Preferably, the provided substrate has a two layer second region, the lowermost layer being of a higher impurity level than the uppermost layer to improve the high voltage performance.
Finally, for improved high voltage performance, a ring of the second conductivity type is formed around the sites for the vertically developed devices in the second volume.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel and distinctive features of the invention are set forth in the claims appended to the present application. The invention itself, however, together with further objects and advantages thereof, may best be understood by reference to the following description and accompanying drawings in which:
FIG. 1 is a block diagram of that portion of a monolithic microprocessor used to provide control of a plurality of load devices and which includes plural power output stages and low voltage logic for their control;
FIG. 2 is an electrical circuit diagram of a power output stage suitable for control of a single load and the immediately associated low voltage logic together with illustrative power, load, and control connections;
FIG. 3 is an electrical circuit diagram of a power output stage modified to include a pair of Darlington connected power transistors, and the immediately associated low voltage logic (power, load, and control connections also being provided);
FIG. 4a is a cross-section of representative devices, including low voltage lateral and vertical devices, and high voltage lateral and vertical devices, as more particularly shown in the circuit diagram of FIG. 4b, drawn below 4a: and
FIG. 5 is a simplified chart of the processing steps for the integrated circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a portion of a monolithic microprocessor suitable for logical control of a plurality of load devices is illustrated. The power interface is illustrated as a portion of a substrate 11 having a first plurality of terminals A, B, C and F for connection to suitable dc supply potentials; a second plurality of terminals E1, E2, E3 and E4 for connection to suitable loads; and an electrically isolated drive equivalently represented by an optical coupler) for introducing control information to the chip. As illustrated in FIGS. 1 and 2, the supply power is coupled through serial resistances R A , R B , R C to substrate terminals A, B and C on the one hand and to ground 23 on the other hand. The supply provides an approximately 150 volt potential for the loads, assuming connection to a 60 cycle, 110 volt ac main through a full wave (or alternately half-wave) rectifier 12. Some capacitive filtering may also be employed to insure continuity of a unidirectional supply potential. The voltages at the terminals A, B and C of the microcircuit are typically 0.7 volts with respect to the substrate contact F, with the voltages at terminals A, B and C being within 0.1 volts of each other as necessary for operation of the I 2 L control logic 27 and the current injectors 25, 26. The 150 volts (FIG. 1) (less the 1-2 V drop in the circuit) appears at the output terminals E 1 , E 2 E 3 and E 4 of the power output stages with respect to ground. The loads L 1 , L 2 , L 3 and L 4 are connected respectively between the output terminals E 1 , E 2 , E 3 and E 4 and ground. The load device L 1 is shown to be a relay for operation of a power device such as an appliance motor requiring more power than may be conveniently controlled by the integrated circuit or a load requiring ac drive, and solenoids L 2 , L 3 and L 4 are provided for actuation of valves, electrical relays, heaters, light bulbs, or other control functions on a single appliance. In a practical example, the loads L 1 through L 4 may each draw 75-100 milliamperes and thus dissipate approximately about 10 watts and total 40 watts. The circuit may also include a load RNL connected between the substrate contact F and ground 23 to sustain the necessary voltage relationships when no load is drawing current. The isolated drive 22, shown schematically in FIG. 2, utilizes a light emitting diode to illuminate a control transistor 30 which may be formed on the same substrate. The control transistor 30 is the input port for applying external control information to the integrated circuit. Internal control is another option.
The substrate 11 contains a shift register 13 (FIG. 1) to which the control information is supplied, a holding register 14 coupled to the shift register, which stores the information provided by the shift register and which has plural outputs D 1 , D 2 , D 3 and D 4 , one used to control each of a plurality of power output stages 15, 16, 17 and 18. Suitable power output stages are illustrated in FIGS. 2 and 3. The substrate also includes a suitable timing and control block 19. The shift register 13, the holding register 14, the timing and control block 19 and the control portion of each power output stage use "integrated injection logic" suited for the low voltage (0.7 volts) energization mentioned above.
FIG. 2 illustrates a first power output stage, which may form a portion of the monolithic substrate 11 and which is suitable for controlling, by means of an optical coupler, the application of power from an ac source to a single load. The power is applied from a 110 volt, 60 cycle ac main through the rectifier 12 to the dc circuit. The positive rectifier terminal is connected via resistances R A , R B and R C to the substrate terminals respectively denominated A, B, and C. The other terminal of the rectifier is connected to node 23, shown as ground. The load (L i ) is coupled between the emitter of a high voltage NPN transistor (terminal E i ) and ground 23. The optical coupler (22,30) provides suitable means for the application of a control signal. The light source of the optical coupler includes a 150 ohm resistor, a 5 volt battery and a light emitting diode. The light emitting diode illuminates a light sensitive NPN transistor 30, shown with the collector connected to the logic input terminal D i and its emitter connected to the substrate contact F. Conduction or non-conduction of transistor 30 determines the state of conduction of the power output stage and controls the application of power to the load L i .
The power output stage has both low voltage I 2 L (Integrated Injection Logic) control components and high voltage power components. The low voltage, control components include the diode 24, lateral current injection transistor 25 for the power components, lateral current injecton transistor 26 (for the last logic gate 27) and the last I 2 L gate vertical transistor 27. The high voltage, power portion of the power output stage includes the lateral PNP transistor 28 and the vertical PNP power transistor 29.
The components of the power output stage on the substrate 11 are interconnected as follows. Diode 24 has its anode coupled to terminal A and its cathode coupled to the substrate contact F where it holds the substrate at a diode drop below the voltage at terminal A. It has sufficient area to carry the current through all loads. As earlier noted, resistances R A , R B and R C adjust the potentials between the substrate terminals A, B and C for proper operation of the low voltage components. The transistor 25 which provides current injection to the power stages has its base connected to the substrate ground F, its emitter coupled to terminal B and its collector connected to the terminal G i and to the emitter of the high voltage lateral PNP transistor 28. The injector 25 provides emitter current for operation of the lateral PNP 28. The transistor 26, which provides current injection to the last I 2 L gate (27), has its base connected to the substrate contact F, its emitter coupled to power input terminal C and its collector coupled to the data input terminal D i and to the base of the I 2 L vertical transistor 27. The emitter of transistor 27 is coupled to the substrate contact, and the two collectors of transistor 27 are joined together and coupled to the emitter of lateral PNP power transistor 28. The base of transistor 28 is connected to the substrate contact and the collector of 28 is connected to the base of the NPN power transistor 29. The power transistor 29 has its collector coupled to the substrate contact and its emitter connected to the power output terminal E i .
The application of power by the power output stage occurs in the following manner. The principal current path connecting the rectifier with the load L i includes in succession: the resistance R A , supply terminal A, diode 24, substrate contact F, the collector and the emitter, respectively, of the power transistor 29, load terminal E i , the load L i , and finally ground 23 to which the rectifier is also returned. When the NPN transistor 29 is conductive, a low impedance path is provided from source to load. When the transistor 29 is nonconductive, the principal current path is broken and no current flows to the load.
The I 2 L vertical transistor 27 and the lateral PNP 28 control the state of the NPN power transistor 29 in response to the control signals applied from the optical source 22 to the light sensitive transistor 30. Assuming normal circuit energization, and the absence of a signal from the optical source, the transistor 30 is off and the terminal D i is unconnected to the substrate ground contact. With transistor 30 nonconducting, the I 2 L current injection transistor 26 supplies current to transistor 27, turning it on and creating a low impedance shunt path between the emitter of the lateral power transistor 28 and the substrate contact. The current injector 25 provides a current (1-5 ma) adequate to turn on the lateral PNP 28, but with the current diverted to the substrate ground by conduction of gate 27, the lateral PNP 28 is held non-conductive. With the lateral PNP 28 non-conductive, inadequate base current is provided to turn on the NPN power transistor 29 and it remains off, keeping the load (L i ) unenergized. In the presence of a signal from the optical source 22, the transistor 30 is turned on and the terminal D i is held approximately to the potential of the substrate contact. With transistor 30 conducting, an alternate path is provided for current from I 2 L current injector 26, diverting current that would have been supplied to the I 2 L transistor 27 and turning it off. The power current injection transistor 25 now supplies current to the emitter of the lateral PNP transistor 28 (which current is no longer diverted by transistor 27) and turns PNP 28 on. With lateral PNP 28 conductive, adequate base current is supplied to the power NPN 29 and it is turned on, energizing the load.
The operation just detailed is efficient in its use of power. The current injection stage 25 for the power stages, the current injection stage 26 for the I 2 L gate 27, and the I 2 L gate 27 all operate at low currents and powers, typically on the order of from 0.1-1 milliamperes at a voltage of about 0.7. The power consumption in the logic stages is thus on the order of from 0.1 to 1 milliwatts. The lateral PNP 28 provides the required voltage gain which, in response to the 0.7 volts control signal, turns on or off the 150 volts used to energize the load. In an exemplary case, the power injection stage 25 provides 1-5 milliamperes of current for the lateral PNP 28. The power NPN operates at approximately 150 volts with from 75-100 milliamperes of load current for control of an approximately 10 watt load. A high voltage requirement is placed on the NPN 29 and the lateral PNP 28, which depends both on the voltage of the power supply, the amount of ripple and the reactance in the load. Both power devices should be designed for high voltage operation, and in the present embodiment a suitable value is 400 volts (RBSOA-Reverse Bias Safe Operating Area).
The power output stage may take another form as illustrated in FIG. 3. In FIG. 3, the NPN power transistor 29 of FIG. 2 is replaced by a pair of Darlington connected power transistors 31 and 32. The connection is conventional with the collector of the transistors being connected to substrate ground, the base of the first transistor 31 being connected to the collector of the lateral PNP 28 (using the same reference numerals as employed in FIG. 2), the emitter of the transistor 31 being connected to the base of the transistor 32 and the emitter of transistor 32 being connected to the load terminal E i . The customary biasing resistances 33 and 34 are provided connected respectively between the base and emitter of transistor 31 and the base and emitter of transistor 32. The Darlington arrangement provides additional current gain over that provided by a single NPN power transistor.
The disparate requirements of the power output stages and the I 2 L logic dictate disparate designs for the semiconductor structures. The former requires a high voltage, high power design on the one hand, and the latter a low voltage, low power design on the other hand. In detail, these disparate requirements dictate a lightly doped thick epitaxial collector, a deep base diffusion, a low base sheet resistivity for the high voltage-components. For the low voltage components, the epitaxial emitters should be heavily doped, the base should be shallower and have a high base sheet resistivity. The manner that this is achieved may be seen from a consideration of FIGS. 4a and 4b.
In FIG. 4a, a cross section of representative integrated devices of the FIG. 3 circuit arrangement is illustrated. The devices structurally represented in FIG. 4a are illustrated by circuit representations immediately beneath in FIG. 4b. The devices in FIGS. 4a and 4b proceeding from left to right, include the I 2 L lateral PNP current injector 26, the I 2 L vertical NPN inverter 27, the high voltage lateral PNP 28, and the Darlington connected vertical NPN power transistors 31 and 32. The I 2 L vertical devices have their emitters down and collectors up, while the NPN power devices are of an opposite orientation with the collectors down and the emitters up. As the nomenclatures suggest, the lateral devices, and in particular the lateral current injector 26, and the lateral PNP power transistor 28, have their (P) emitter, (N) base, and (P) collector regions arranged side by side, proceeding from left to right in FIG. 4a.
The scale conventions of FIG. 4a should also be explained. The silicon substrate 11, in the present embodiment, is approximately 8 mils in thickness, developed on the upper surface and has a metallic contact 40 on the under surface. The major portion of the substrate is a very highly doped N+ region 41 having a bulk resistivity of approximately 0.005-0.016 ohm centimeters. The 70 micron epitaxial layer is in turn subdivided into a lower layer 42 of approximately 20 microns thickness having a bulk resistivity of 11/2 ohm centimeters, and an upper layer 43 of approximately 50 microns thickness, having a bulk resistivity of ≃50 ohm cms, in which the active devices are formed. The deepest device structures, measuring from the upper surface of the epitaxial layer 43, have a downward penetration of approximately 15 microns. In general, vertical scale consistency has been preserved between the upper P and N regions. The lateral scale of the P and N regions is arbitrary for ease in illustration. The surface areas of the actual devices should in fact reflect the currents and power involved. In practice, the I 2 L logic is quite small, occupying perhaps 10 to 20% of the surface area of the substrate (assigned to a power output stage), while the lateral PNP 28 and the Darlington transistors 31, 32 are quite large, occupying 90 to 80% of the same surface area.
The particulars and functions of the structures shown in FIG. 4a may be understood by reference to the circuit representations of FIG. 4b. The leftmost devices 26 and 27 are formed of the regions 44, 45, 46, 47, 48 and portions of the layers (40-43) beneath region 44. Commencing at the upper left side of the figure, an "N" region 44 is shown extending downward to a depth of approximately 12 microns from the upper surface of the substrate. The leftmost portion of region 44 underlies a shallow P region 45, extending downward 2-3 microns from the upper surface of the substrate. P region 45 bears a contact and is the emitter of the lateral PNP 26. The "N" denotes a more heavy doping than that of the underlying layer 43 denoted "N-". An extension 59 of region 44 extends upwardly to the top surface of the substrate to the right of region 45 and serves as the base region of the lateral PNP 26. A second shallow P region 46 extends downward 2-3 microns from the upper surface of the substrate overlying the rightmost portion of region 44. The leftmost portion of P region 46 forms the collector of the lateral PNP 26 completing that device. The rightmost portion of the P region 46 forms the intrinsic base of the I 2 L inverter 27, overlying the rightmost portion of the region 44, which with portions of the underlying layers 40, 43, is the emitter of the inverter 27. The N+ regions 47 and 48 formed to a depth of 1-2 microns into the upper surface of P region 46, which are electroded, provide the two collectors of the inverter 27, and complete the device.
The next device to the right is the high voltage lateral PNP transistor 28, which as will be seen, shares a P region with the vertical NPN power transistor 31. The shallow (2-3 microns) P region 49 is the emitter of the lateral PNP 28, and is formed in a deeper N region 50, extending beneath and bounding the emitter region 49 on the right-hand side. The N region 50, like region 44, is more heavily doped than the N- layer 43. The upper extension (51) of the N region 50 is of higher conductivity than the N- region 52 (an upward extension of the layer 43) immediately to the right. The N, N- regions 51 and 52 form the base of the lateral PNP 28. The region 53 which is a deep P ring developed to a depth of approximately 15 microns around the vertical NPN power devices, forms the collector of the lateral PNP. The N portion 51 of the base region provides a high voltage barrier permitting a shorter width base region than if the N- region 52 alone existed, and thus enhances the gain of the lateral device. The graded base attributable to the ion implantation further enhances the gain of the lateral PNP.
The last two devices to the right are the high voltage vertical NPN power transistors 31 and 32. They are disposed within the deep guard ring 53 and their collectors share that portion 54 of the N- layer 43 between the guard rings and the portion of the N- layer 43 beneath the portion 54. The leftmost portion of 54 and the underlying portion of the layers 40-43 form the collector of the first NPN 31. The P region 55 immediately above extending downwardly 3-4 microns, is the base of the first NPN 31. An N+ region 56 extending downwardly 1-2 microns into the P region 55 is the emitter, completing the first vertical NPN 31 of the power Darlington. The second vertical NPN 32 is similarly formed. The collector of 32 consists of the rightmost portion of 54 and the underlying portion of regions 40-43. The base and emitter of NPN 32 consist of the P region 57 and the N+ region 58, formed into region 57. In both NPN devices 31 and 32, the base P regions 55 and 57 are each electroded. Both base regions surround the respective shallower emitter regions 56 and 58 included therein; both base regions are mutually separated by an upwardly extending portion of N- region 54, and both base regions are in contact with the surrounding guard ring 53. Thus, the left-most portion of the guard ring 53, which forms the collector of lateral PNP 28 maintains electrical continuity with the P base region 55 of NPN 31, and supplies the illustrated electrical connection between the devices.
In the matter of surface area, the lateral PNP is a large area device, much larger than any I 2 L device, having a surface area comparable to that of the NPN 31. The NPN device 32 has typically three to four times the surface area of the NPN 31.
The composite integrated circuit illustrated in FIGS. 4a and 4b may be fabricated in a relatively simple process which is outlined in FIG. 5. That process and additional features of the finished integrated circuit will now be explained. The initial substrate is a 16 mil (0.4 mm) N+ wafer, later lapped to 8 mil (0.2 mm), having the two step collector 42, 43. The substrate selection is optimized for fabrication of the NPN power device. The process will be seen to follow the conventional steps for fabrication of the NPN devices with certain novel modifications introduced to also permit convenient fabrication of the low voltage I 2 L devices.
The two step N, N- regions 42, 43 enhance the Reverse Bias Safe Operating Area (RBSOA) of the power NPNs 31, 32, and reduce leakage to the substrate of the lateral PNPs (26, 28). The effect also improves the gain of these devices. In general, both effects are more pronounced upon the high voltage lateral PNP.
Accordingly, as shown in FIG. 5, the first step of the process is the provision of an N+ substrate having a two step N, N- epitaxial layer.
The second step of the process is the ion implantation of the I 2 L logic and a part of the base of the lateral HV PNP. The ion implantation is done with a thick oxide coating the epitaxial layer except for a window formed for the I 2 L logic and for a part of the base of the PNP 28. The implantation may be of phosphorous and should be diffused into approximately 10-12 microns in depth. (The diffusion is achieved simultaneously with the deep P ring diffusion performed at a later stage.) The impurity count of the N- region is 10 14 atoms per cm 3 , while that of the implantation commences at a number in excess of 10 16 atoms per cm 3 at the surface, tailing off non-linearly to 10 14 at a 9-10 microns depth.
The third step of the process is the formation of a voltage enhancing ring for the power Darlington. The step is performed by creating a ring-shaped opening in a thick oxide window drawn around the perimeter of the two devices. The step may be performed with a deep P diffusion to 15-17 microns, which extends well below the base of the Darlington NPNs. Alternatively, a shallow P- implantation may be employed continued to a depth slightly less than that of the bases of the Darlington NPNs.
The fourth step of the process is the simultaneous diffusion of the shallow P regions for the I 2 L logic and the slightly deeper P regions for the power bases. Due to the differing initial impurity levels of the I 2 L logic and the bases of the power NPNs, the same diffusion, which produces a P region to a 2-3 micron depth in the I 2 L logic, will produce a P region to a 3-4 micron depth in the base of the power NPN.
The fifth step of the process is the simultaneous diffusion of the N+ region for the I 2 L collectors and the emitters of the power NPNs. In this step, both N+ regions continue down to a depth of aproximately 2 microns, leaving a shallow base of less than a micron thickness for the I 2 L device, and a thicker base of nearly two microns for the base of the power NPNs.
The sixth step is the formation of the contacts on the upper and lower surfaces of the substrate. This step includes the lapping of the underside of the substrate to the final thickness prior to application of the substrate contact.
The introduction of the phosphorous implantation into the I 2 L logic and into the lateral HV PNP permits one to modify a process otherwise optimized for processing the NPN Darlington devices to achieve greatly improved performance for all three. The high voltage components require a deeper base diffusion, a lightly doped, thick epitaxial layer and a generally low base sheet resistivity. The I 2 L devices on the other hand require a shallow base diffusion, a highly doped epitaxial emitter, and a high base sheet resistivity. These conflicting requirements are met by the process herein described. The original substrate is selected with the requirements of the high voltage components in mind. The introduction of the phosphorous implantation forces the base diffusion to be narrow, as earlier noted, by essentially reducing the depth of the lower surface of the I 2 L P diffusion in respect to the P diffusion for the power devices. Since the N+ diffusions of both devices are of constant depth, the net thickness of the two base regions differ by approximately two by one. The emitters in the I 2 L devices should be highly doped, a condition which is produced by the implantation. The configuration also provides a separate control of the sheet base resistivity, which may be higher for the I 2 L device than for the power NPNs.
As earlier noted, the N+ ion implantation instituted to improve the I 2 L, but carried on simultaneously in the base region of the lateral HV PNP 28, improves the high voltage performance. Similarly, the deep P ring or the P ion implantation helps achieve a like high voltage performance on the part of the Darlington NPNs. Also, the two step collector structure (the N, N- regions 42, 43), which improves the voltage performance of the NPNs also improves the current gain of the lateral HV PNP. Thus, several of the steps have plural benefits.
Other variations of the invention are practical. The electrical circuit may provide increased power by increasing the areas of the power devices. The I 2 L logic, while shown having separate power connections (A, B, C), may also be energized by a single connection, with suitable adjustments of the electrical design, including elimination of the resistors R A , R B , R C .
In the processing, the initial substrate is conventionally antimony doped for the N+ region, with the epitaxial layer of phosphorous. Equivalent dopants may also be used. The P implantation and P diffusions (steps 3 and 4) are preferably boron but may be the other conventional dopants. The N implantation and N diffusion is typically phosphorous but may use other N type materials.
While the practical embodiment shows four 10 watt loads, one may readily scale down or scale up the power semiconductors to accommodate smaller or larger individual loads. One may also accommodate larger numbers of loads by the addition of additional power output stages. Likewise, the complexity of the I 2 L logic may also be increased (or lessened) as desired to achieve a desired load control function.
While the illustrated embodiments show a bridge rectifier and a filter capacitor across the dc terminals of the bridge, other variations are possible. For instance, half-wave rectification may be adequate or desirable from the viewpoint of energizing ac solenoids. Filter capacity may be reduced if it is connected between terminals C and F to insure continuous logic operation.
The PNP power injector is fabricated by the same process steps as the I 2 L injector, but has approximately 10 times more area for higher currents. Alternatively, the injection current into the PNP may be supplied by a resistance connected to terminal G i .
|
An integrated circuit incorporating high voltage semiconductor devices which are controlled by low voltage semiconductor devices is disclosed, including a method for making the same. The low voltage devices which are capable of realizing complex logic functions on the same chip are realized with only one simple extra step in the fabrication process as compared with the process used to fabricate discrete high voltage power transistors. The process addition to implant the low voltage device does not significantly degrade the original capability associated with discrete power transistors. Both laterally developed and vertically developed devices are described. The integrated circuit combines I 2 L logic with power Darlington transistors. A large area ion implantation permits one to fabricate both low and high voltage devices on one substrate. The resulting integrated circuit permits a plurality of loads to be controlled by a simple or complex control function.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority from U.S. provisional application no. 60/236,342 filed Sep. 29, 2000.
TECHNICAL FIELD
[0002] The invention relates to the field of natural language processing, and more particularly to a method and system for processing synonyms.
BACKGROUND OF THE INVENTION
[0003] A key part of adapting natural language processing (NLP) applications to specific domains is the adaptation of their lexical and terminological resources. However, parts of a general-purpose terminological resource may consistently be unrelated to and unused within a specific domain, thereby creating a persistent and unnecessary amount of ambiguity that affects both the accuracy and efficiency of the NLP application.
[0004] The present invention presents a method for processing synonyms that adapts a general-purpose synonym resource to a specific domain. The method selects out a domain-specific subset of synonyms from the set of general-purpose synonyms. The synonym processing method in turn comprises two methods that can be used either together or on their own. A method of synonym pruning eliminates those synonyms that are inappropriate in a specific domain. A method of synonym optimization eliminates those synonyms that are unlikely to be used in a specific domain.
[0005] A method for adapting a general-purpose synonym resource to a specific domain has many applications. Two such applications are information retrieval (IR) and domain-specific thesauri as a writer's aid.
[0006] Synonyms can be an important resource for IR applications, and attempts have been made at using them to expand query terms. See Voorhees, E. M., “Using WordNet for Text Retrieval,” In C. Fellbaum (Ed.), Wordnet: An Electronic Lexical Database . MIT Press Books, Cambridge, Mass., chapter 12, pp. 285-303 (1998). In expanding query terms, overgeneration is as much of a problem as incompleteness or lack of synonym resources. Precision can dramatically drop because of false hits due to incorrect synonymy relations, that is, incorrect pairings of terms as synonyms. This problem is particularly felt when IR is applied to documents in specific technical domains. In such cases, the synonymy relations that hold in the specific domain are only a restricted portion of the synonymy relations holding for a given language at large. For instance, a set of synonyms like cocaine, cocain, coke, snow, C
[0007] valid for English in general, would be detrimental in a specific domain like weather reports, where the terms snow and C (for Celsius) both occur very frequently, but never as synonyms of each other.
[0008] A second application is domain-specific thesauri as a writer's aid. When given a target word, thesauri in word processors generally list sets of synonyms organized by part of speech, and then by sense, e.g., for snow, a thesaurus might present a listing as follows:
[0009] noun (1) precipitation falling from clouds in the form of ice crystals snowfall
[0010] noun (2) a narcotic (alkaloid) extracted from coca leaves cocaine, cocain, coke, C
[0011] verb (1) . . .
[0012] A thesaurus tailored to a specific domain would select, or at least order, the likely part of speech of a target word, the likely sense of that word for that part of speech, and favoured synonym terms for that sense. The methods described in the present invention can help provide such functionality.
[0013] In both applications and others in NLP, the methods described in the present invention provide a way to automatically or semi-automatically adapt sets of synonyms to specific domains, without requiring labour-intensive manual adaptation.
[0014] The method of synonym pruning in the present invention has an obvious relationship to word sense disambiguation (Sanderson, M., Word Sense Disambiguation and Information Retrieval , Ph.D. thesis, Technical Report (TR-1997-7), Department of Computing Science at the University of Glasgow, Glasgow G12 (1997); Leacock, C., Chodorow, M., and G. A. Miller, “Using Corpus Statistics and WordNet Relations for Sense Identification,” Computational Linguistics , 24, (1), pp. 147-165 (1998)), since both are based on identifying senses of ambiguous words in a text. However, the two tasks are quite distinct. In word sense disambiguation, a set of candidate senses for a given word is checked against each occurrence of the relevant word in a text, and a single candidate sense is selected for each occurrence of the word. In synonym pruning, a set of candidate senses for a given word is checked against an entire corpus, and a subset of candidate senses is selected. Although the latter task could be reduced to the former (by disambiguating all occurrences of a word in a test and taking the union of the selected senses), alternative approaches could also be used. In a specific domain, where words can be expected to be monosemous (i.e., having only a single sense) to a large extent, synonym pruning can be an effective alternative (or a complement) to word sense disambiguation.
[0015] From a different perspective, synonym pruning is also related to the task of assigning Subject Field Codes (SFC) to a terminological resource, as done by Magnini and Cavaglià (2000) for WordNet. See Magnini, B., and G. Cavaglià, “Integrating Subject Field Codes into WordNet,” In M. Gavrilidou, G. Carayannis, S. Markantonatou, S. Piperidis, and G. Stainhaouer (Eds.) Proceedings of the Second International Conference on Language Resources and Evaluation (LREC-2000), Athens, Greece, pp. 1413-1418 (2000). In WordNet a set of synonyms is known as a “synset”. Assuming that a specific domain corresponds to a single SFC (or a restricted set of SFCs, at most), the difference between SFC assignment and synonym pruning is that the former assigns one of many possible values to a given synset (one of all possible SFCs), while the latter assigns one of two possible values (the words belongs or does not belong to the SFC representing the domain). In other words, SFC assignment is a classification task, while synonym pruning can be seen as a ranking/filtering task.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a block diagram of the synonym processor module comprising a synonym pruner and synonym optimizer;
[0017] [0017]FIG. 2 is a block diagram of the synonym processor module comprising a synonym pruner;
[0018] [0018]FIG. 3 is a block diagram of the synonym processor module comprising a synonym optimizer;
[0019] [0019]FIG. 4 is a block diagram of the synonym pruner module shown in FIG. 1 and FIG. 2 comprising manual ranking, automatic ranking, and synonym filtering;
[0020] [0020]FIG. 5 is a block diagram of the synonym pruner module shown in FIG. 1 and FIG. 2 comprising manual ranking and synonym filtering;
[0021] [0021]FIG. 6 is a block diagram of the synonym pruner module shown in FIG. 1 and FIG. 2 comprising automatic ranking and synonym filtering;
[0022] [0022]FIG. 6 a is a block diagram of the synonym pruner module shown in FIG. 1 and FIG. 2 comprising automatic ranking, human evaluation, and synonym filtering;
[0023] [0023]FIG. 7 is a block diagram of the synonym optimizer module shown in FIG. 1 and FIG. 3 comprising removal of irrelevant and redundant synonymy relations;
[0024] [0024]FIG. 8 is a block diagram of the synonym optimizer module shown in FIG. 1 and FIG. 3 comprising removal of irrelevant synonymy relations;
[0025] [0025]FIG. 9 is a block diagram of the synonym optimizer module-shown in FIG. 1 and FIG. 3 comprising removal of redundant synonymy relations.
DESCRIPTION
[0026] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. Well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense. The present invention consists of a number of component methods where each component method is described in various configurations. For each component method, a preferred embodiment of the various configurations for that component method has been described. For particular examples of the application of the invention, reference is made to the method and system disclosed in Turcato, D., Popowich, F., Toole, J., Fass, D., Nicholson, D., and G. Tisher, “Adapting a Synonym Database to Specific Domains,” In Proceedings of the Association for Computational Linguistics (ACL) '2000 Workshop on Recent Advances in Natural Language Processing and Information Retrieval, 8 Oct. 2000, Hong Kong University of Science and Technology, pp. 1-12 (2000)., (cited hereafter as “Turcato et al. (2000)”) which is incorporated herein by reference.
[0027] 1. Synonym Processor
[0028] [0028]FIG. 1, FIG. 2, and FIG. 3 are simplified block diagrams of a synonym processor 110 , 210 , and 310 in various configurations. The synonym processor 110 , 210 , and 310 takes as input a synonym resource 120 , 220 , and 320 such as WordNet, a machine-readable dictionary, or some other linguistic resource. Such synonym resources 120 , 220 , and 320 contain what we call “synonymy relations.” A synonymy relation is a binary relation between two synonym terms. One term is a word-sense; the second term is a word that has a meaning synonymous with the first term. Consider, for example, the word snow, which has several word senses when used as a noun, including a sense meaning “a form of precipitation” and another sense meaning “slang for cocaine.” The former sense of snow has a number of synonymous terms including meanings of the words snowfall and snowflake. The latter sense of snow includes meanings of the words cocaine, cocain, coke, and C. Hence, snowfall and snowflake are in a synonymy relation with respect to the noun-sense of snow meaning “a form of precipitation.”
[0029] [0029]FIG. 1 shows the preferred embodiment in which the synonym processor 130 comprises a synonym pruner 150 and synonym optimizer 170 . This is the configuration described in Turcato et al. (2000) referenced above. The rest of the description assumes this configuration, except where stated otherwise.
[0030] [0030]FIG. 2 and FIG. 3 are simplified block diagrams of the synonym processor 210 and 310 in two less favoured configurations. FIG. 2 is a simplified block diagram of the synonym processor 210 containing just the synonym pruner 250 . FIG. 3 is a simplified block diagram of the synonym processor 310 containing just the synonym optimizer 380 .
[0031] 1.1. Synonym Pruner
[0032] [0032]FIG. 4, FIG. 5, and FIG. 6 are simplified block diagrams of the synonym pruner 415 , 515 , and 615 in various configurations. The synonym pruner 415 , 515 , and 615 takes as input a synonym resource 410 , 510 , and 610 such as WordNet, a machine-readable dictionary, or some other linguistic resource. The synonym pruner 415 , 515 , and 615 produces those synonymy relations required for a particular domain (e.g., medical reports, aviation incident reports). Those synonymy relations are stored in a pruned synonym resource 420 , 520 , and 620 .
[0033] The synonym resource 410 , 510 , and 610 is incrementally pruned in three phases, or certain combinations of those phases. In the first two phases, two different sets of ranking criteria are applied. These sets of ranking criteria are known as “manual ranking” 425 , 525 , and 625 and “automatic ranking” 445 , 545 , and 645 . In the third phase, a threshold is set and applied. This phase is known as “synonym filtering” 455 , 555 , and 655 .
[0034] [0034]FIG. 4 shows the preferred embodiment in which the synonym pruner 415 comprises manual ranking 425 , automatic ranking 445 , and synonym filtering 455 . This is the configuration used by Turcato et al. (2000). The rest of the description assumes this configuration, except where stated otherwise.
[0035] [0035]FIG. 5 and FIG. 6 are simplified block diagrams of the synonym pruner 515 and 615 in two less favoured configurations. FIG. 5 is a simplified block diagram of the synonym pruner 515 containing just manual ranking 525 and synonym filtering 555 . FIG. 6 is a simplified block diagram of the synonym pruner 605 containing just automatic ranking 645 and synonym filtering 655 .
[0036] A variant of FIG. 6 is FIG. 6 a , in which the automatically ranked synonym resource 650 a produced by the human evaluation of domain-appropriateness of synonymy relations 645 a is passed to human evaluation of domain-appropriateness of synonymy relations 652 a before input to synonym filtering 655 a.
[0037] The manual ranking process 425 consists of automatic ranking of synonymy relations in terms of their likelihood of use in the specific domain 430 , followed by evaluation of the domain-appropriateness of synonymy relations by human evaluators 435 .
[0038] The automatic ranking of synonymy relations 430 assigns a “weight” to each synonymy relation. Each weight is a function of (1) the actual or expected frequency of use of a synonym term in a particular domain, with respect to a particular sense of a first synonym term, and (2) the actual or expected frequency of use of that first synonym term in the domain. For example, Table 1 shows weights assigned to synonymy relations in the aviation domain between the precipitation sense of snow and its synonym terms cocaine, cocain, coke, and C.
TABLE 1 Synonymy relation between precipitation sense of snow and a sysnonym term Weight cocaine 1 cocain 0 coke 8 C 9168
[0039] Data about the actual or expected frequency of use of a synonym term is derivable from a number of domain sources. A primary source of frequency data is some domain corpus, for example, some collection of text documents from a particular domain. Another possible source of frequency data is a history of the use of a term in some particular application. An example of such a historical use is a collection of past queries or a term list in an information retrieval application. Another example is a history of the synonym terms selected by a user from a thesaurus in a word processor.
[0040] When multiple sources of frequency data are available within a domain, the “weight” of each synonymy relation can be derived somewhat differently from the case where a single source of frequency data is available. The “weight” is again a function of the actual or expected frequency of use of the synonym terms in a synonymy relation, but now the actual or expected frequency of use can be derived from the multiple data sources. For example, in an information retrieval application, the weight of a synonymy relation can be derived from the frequencies of actual or expected use of its synonym terms in both a domain corpus (e.g., a collection of documents) and a collection of past queries. In this case, the weights of such synonymy relations would provide an estimate of how often a given term in the domain corpus is likely to be matched as a synonym of a given term in a query.
[0041] One possible method and system (of many possible methods and systems) for the automatic ranking of synonymy relations 430 that may be used with the present invention is described in section 2.2.1 of Turcato et al. (2000). Where no inventory of relevant prior queries exists for the domain then the ranking may be simply in terms of domain corpus frequency. Where an inventory of relevant prior queries exists, then the ranking uses the frequency of the occurrence of the term in the domain corpus and the inventory of query terms to estimate how often a given synonymy relation is likely to be used.
[0042] The set of synonymy-relations and their weights are then ranked from greatest weight to least, and then presented in that ranked order to human evaluators for assessment of their domain-appropriateness 435 . The weights are useful if there are insufficient evaluators to assess all the synonymy relations, as is frequently the case with large synonym resources 410 . In such cases, evaluators begin with the synonymy relations with greatest weights and proceed down the rank-ordered list, assessing as many synonymy relations as they can with the resources they have available.
[0043] The judgement of appropriateness of synonymy relation in a domain might be a rating in terms of a binary Yes-No or any other rating scheme the evaluators see fit to use (e.g., a range of appropriateness judgements).
[0044] The output of manual ranking 425 is a manually ranked synonym resource 440 . The manually ranked synonym resource 440 is like the synonym resource 410 , except that the synonymy relations have been ranked in terms of their relevance to a specific application domain. No synonymy relations are removed during this phase.
[0045] In the second phase of the preferred embodiment shown in FIG. 4, the manually ranked synonym resource 440 is automatically ranked 445 . Automatic ranking 445 is based on producing scores representing the domain-appropriateness of synonymy relations. The scores are produced from the frequencies of the words involved in the synonymy relation, and the frequencies of other semantically related words. Those words involved in the synonymy relation are presently, but need not be limited to, terms from the lists of synonyms and dictionary definitions for words. Other semantically related words include, but need not be limited to, superordinate and subordinate terms for words.
[0046] The semantically words used in automatic ranking 445 may come from a number of sources. A primary source is a general-purpose synonym resource (e.g., a machine-readable dictionary or WordNet), most obviously, the general-purpose synonym resource that is being pruned 410 . However, other sources are possible, for example, taxonomies and classifications of terms available online and elsewhere.
[0047] The frequency of use of those semantically related words is derivable from a number of sources also. Sources of word frequency data include those mentioned during the earlier explanation of how weights were assigned during the automatic ranking of synonymy relations 430 (e.g., a domain corpus such as a collection of documents, a collection of past queries). Other potential sources of frequency data include, but are not limited to, general-purpose synonym resources (e.g., a machine-readable dictionary or WordNet), including the general-purpose synonym resource that is being pruned 410 .
[0048] One possible method and system (of many possible methods and systems) for the automatic ranking of the domain-appropriateness of synonymy relations 445 that may be used with the present invention is described in section 2.3 of Turcato et al. (2000).
[0049] The output of automatic ranking 445 is an automatically ranked synonym resource 450 of the same sort as the manually ranked synonym resource 440 , with the ranking scores attached to synonymy relations. Again, no synonymy relations are removed during this phase.
[0050] In synonym filtering 455 , a threshold is set 460 and applied 465 to the automatically ranked synonym resource 450 , producing a filtered synonym resource 470 . It is during this phase of synonym pruning 460 that synonymy relations are removed.
[0051] The threshold setting 460 in the preferred embodiment is flexible and set by the user through a user interface 415 , though neither needs to be the case. For example, the threshold could be fixed and set by the system developer or the threshold could be flexible and set by the system developer.
[0052] The three phases just described can be configured in ways other than the preferred embodiment just described. Firstly, strictly speaking, automatic pruning 445 could be performed manually, though it would require many person-hours on a synonym resource 410 of any size. Second, in the preferred embodiment, the pruned synonym resource 410 is the result of applying two rounds of ranking. However, in principle, the pruned synonym resource 420 could be the result of just one round of ranking: either just manual ranking 525 as shown in FIG. 5 or just automatic ranking 645 as shown in FIG. 6.
[0053] 1.2. Synonym Optimizer
[0054] [0054]FIG. 7, FIG. 8, and FIG. 9 are simplified block diagrams of the synonym optimizer 710 , 810 , and 910 in various configurations. Input to of the synonym optimizer 710 , 810 , and 910 is either an unprocessed synonym resource 720 , 820 , and 920 or a pruned synonym resource 730 , 830 , and 930 . The input is a pruned synonym resource 730 , 830 , and 930 in the preferred embodiment of the synonym processor (shown in FIG. 1). The input is an unprocessed synonym resource 720 , 820 , and 920 for one of the other two configurations of the synonym processor (shown in FIG. 3).
[0055] Output is an optimized synonym resource 750 , 850 , and 950 .
[0056] The synonym optimizer 710 , 810 , and 910 removes synonymy relations that, if absent, either do not affect or minimally affect the behaviour of the system in a specific domain. It consists of two phases that can be used either together or individually. One of these phases is the removal of irrelevant synonymy relations 760 and 860 ; the other is the removal of redundant synonymy relations 770 and 970 .
[0057] [0057]FIG. 7 shows the preferred embodiment in which the synonym optimizer 710 comprises both the removal of irrelevant synonymy relations 760 and the removal of redundant synonymy relations 770 . This is the configuration used by Turcato et al. (2000). The rest of the description assumes this configuration, except where stated otherwise.
[0058] [0058]FIG. 8 and FIG. 9 are simplified block diagrams of the synonym optimizer 810 and 910 in two less favoured configurations. FIG. 8 is a simplified block diagram of the synonym optimizer 810 containing just the removal of irrelevant synonymy relations 860 . FIG. 9 is a simplified block diagram of the synonym optimizer 910 containing just the removal of redundant synonymy relations 970 .
[0059] The removal of irrelevant synonymy relations 760 eliminates synonymy relations that, if absent, either do not affect or minimally affect the behaviour of the system in a particular domain. One criterion for the removal of irrelevant synonymy relations 760 is: a synonymy relation that contains a synonym term that has zero actual or expected frequency of use in a particular domain with respect to a particular sense of a first synonym term. For example, Table 1 shows weights assigned in the aviation domain for synonymy relations between the precipitation sense of snow and its synonym terms cocaine, cocain, coke, and C. The table shows that the synonym term cocain has weight 0, meaning that cocain has zero actual or expected frequency of use as a synonym of the precipitation sense of snow in the aviation domain. In other words, the synonymy relation (precipitation sense of snow, cocain) in the domain of aviation can be removed.
[0060] Note that the criterion for removing a synonym term need not be zero actual or expected frequency of use. When synonym resources are very large, an optimal actual or expected frequency of use might be one or some other integer. In such cases, there is a trade-off. The higher the integer used, the greater the number of synonymy relations removed (with corresponding increases in efficiency), but the greater the risk of a removed term showing up when the system is actually used.
[0061] In most cases, users will accept that irrelevant synonym terms are those with zero actual or expected frequency of use. However, the user interface 740 allows users to set their own threshold for actual or expected frequency of use, should they want to.
[0062] A possible method and system (of many possible methods and systems) for the removal of irrelevant synonymy relations 760 that may be used with the present invention is described in section 2.4.1 of Turcato et al. (2000). In particular, terms which never appear in the domain corpus are considered to be irrelevant. If the domain corpus is sufficiently large, then terms which appear in a low frequency may still be considered to be irrelevant.
[0063] The removal of redundant synonymy relations 770 eliminates redundancies among the remaining synonymy relations. Synonymy relations that are removed in this phase are again those that can be removed without affecting the behaviour of the system.
[0064] A possible method and system (of many possible methods and systems) for the removal of redundant synonymy relations 770 that may be used with the present invention is described in section 2.4.2 of Turcato et al. (2000). In particular, sets of synonyms which contain a single term (namely the target term itself) are removed as are sets of synonyms which are duplicates, namely are identical to another set of synonyms in the resource which has not been removed.
[0065] The output of optimization 710 is an optimized synonym resource 750 , which is of the same sort as the unprocessed synonym resource 720 and pruned synonym resource 730 , except that synonymy relations that are irrelevant or redundant in a specific application domain have been removed.
[0066] Note that optimization 710 could be used if the only synonym resource to be filtered 455 was the manually ranked synonym resource 440 produced by manual ranking 425 within synonym pruning 405 . Indeed, optimization 710 would be pretty much essential if manual ranking 425 and filtering 455 was the only synonym pruning 405 being performed. Optimization 710 could also in principle be performed between manual ranking 425 and automatic ranking 445 , but little is gained from this because irrelevant or redundant synonymy relations in the manually ranked synonym resource 440 do not affect automatic pruning 445 .
|
A method and system for processing synonyms that adapts a general-purpose synonym resource to a specific domain. The method selects out a domain-specific subset of synonyms from the set of general-purpose synonyms. The synonym processing method in turn comprises two methods that can be used either together or on their own. A method of synonym pruning eliminates those synonyms that are inappropriate in a specific domain. A method of synonym optimization eliminates those synonyms that are unlikely to be used in a specific domain. The method has many applications including, but not limited to, information retrieval and domain-specific thesauri as a writer's aid.
| 6
|
This application is a divisional of application Ser. No. 08/856,660, filed May 15, 1997 now U.S. Pat. No. 6,030,445.
BACKGROUND OF INVENTION
This invention generally pertains to multicomponent liquid mixtures including tetraethylorthosilicate, triethylborate, and triethylphosphorus compound.
In the manufacture of semiconductor devices, it is often desirable to dope a silicon layer or structure with boron and phosphorus. Historically, such doping has been performed from separate high purity containers and by co-deposition of boron and phosphorus oxides. More recently, there have been efforts to combine a typical source of silicon, such as tetraethylorthosilicate (TEOS) with trimethylborate and trimethylphosphite to provide a mixture used as a reactant source to directly form borophosphosilicate glass. This mixture had several problems, including transesterification of the components and significant depletion effects, as described by R. A. Levy et al., J. Electrochem. Soc., Volume 134, Number 7, pages 1744-1749 (July, 1987). It was reported that the depletion effects resulted in a fairly rapid decrease in thickness and phosphorus content of the films along the length of the reaction chamber. The authors of this article proposed moving away from TEOS as a reactant, instead employing diacetoxyditertiarybutoxysilane (DADBS) as the reactive component for silicon. However, TEOS continues to be the most commonly used compound for silicate deposition.
Furthermore, other industry trends that promote the use of cocktail mixtures include the growing need for single wafer deposition systems and the use of liquid mass flow controllers (LMFC) for 300 millimeter wafers. LMFCs are used instead of bubblers and simple vapor delivery systems for the transport of the needed dopants to the deposition chamber. Cocktail mixtures are not feasible in bubbler or vapor delivery systems due to the differences in vapor pressures of the individual components of the mixture. The composition of the vapor flow will vary in concentration as the cocktail is consumed and will not result in a repeatable, manufacturable process. Several other issues make bubblers and vapor delivery less desirable and expensive, namely, the poor performance of vapor MFCs due to temperature dependency and condensation issues; temperature controllers for each individual source; expensive “hot boxes” that are required; temperature control of all delivery lines, valves, MFCs, and the like. Similarly, a syringe pump and a controlled leak methodology are not as accurate, have moving parts (particle generator), require frequent maintenance for seal replacement, and have no feedback controls for automation.
On the other hand, LMFCs have been found to be simpler and more controlled. The pure liquid or cocktail mixture is transported to the LMFC where the exact flow is controlled. The use of cocktails in an LMFC is desirable since they are not boiling point dependent, LMFCs do not produce particles during operation, and since LMFCs are considered to be more accurate than syringes. The liquid is then flash vaporized very near to the chamber and delivered via a “transport” gas to the wafer surface. The flash vaporizer is capable of handling multi-component mixtures with no known problems. Accordingly, choice of dopant is not determined by its boiling point, but instead on reactivity and stability. It is expected that use of LMFCs will continue to expand as the film requirements become more strict. The film requirements are a function of the need for thinner films as well as the need to provide repeatability and uniformity for 300 mm wafer processes.
The inventor herein has recognized that a need exists for a multicomponent mixture to serve as a feed stock for borophosphosilicates during semiconductor fabrication. This need is particularly timely given the recent trend toward use of LMFCs during semiconductor fabrication. Such a multicomponent mixture would provide a number of benefits such as simplified delivery systems requiring a single channel for doped silicon oxide production; reduction of process variables due to the simplified system; improved system reliability (i.e., mechanical pumps not being exposed to pure trimethylborate and trimethylphosphite flow during wafer transport), fixed stoichiometry of the reactants which makes the chemical source less dependent on exact calibration of flow controllers, pressures, and efficiency of mixing, and less chemicals to handle.
SUMMARY OF INVENTION
This invention provides a solution to one or more of the needs, disadvantages, and shortcomings described above.
In one broad respect, this invention is a composition useful in the manufacture of semiconductors, comprising a liquid mixture of: tetraethylorthosilicate, triethylborate, and a triethylphosphorus compound. The tetraethylorthosilicate, triethylborate, and triethylphosphorus compound may be present in amounts effective to provide a borophosphosilicate that is formed on a substrate by plasma deposition that contains boron and phosphate in a percentage ratio of about 5/5, about 5/3, about 3/3, about 4/4, or about 3/6. In one embodiment of this invention, the components of the liquid mixture each have a purity of at least 99.99%. In one embodiment of this invention, the liquid mixture comprises (a) from about 60% to about 80% tetraethylorthosilicate, (b) from about 15% to about 30% triethylborate, and (c) from about 4% to about 10% triethylphosphorus compound, and wherein the percentages are measured by weight and total 100% for components (a), (b), and (c). In another embodiment of this invention, the liquid mixture may further comprise a triethoxyarsenic compound, such as triethoxy arsenate.
In a second broad respect, this invention is a composition useful in the manufacture of semiconductors, comprising a liquid mixture of: (a) from about 60% to about 80% tetraethylorthosilicate, (b) from about 15% to about 30% triethylborate, and (c) from about 4% to about 10% triethylphosphate, wherein the percentages are measured by weight and total 100% for components (a), (b), and (c).
In a third broad respect, this invention is a method useful for the preparation of a liquid mixture useful in the manufacture of semiconductors, comprising the steps of: obtaining (a) tetraethylorthosilicate, (b) triethylborate, and (c) a triethylphosphorus compound; combining components (a), (b), and (c) and mixing the components to form the liquid mixture. In one embodiment, the mixing step occurs prior to adding the components to the container.
In yet another broad respect, this invention is a stainless steel canister containing tetraethylorthosilicate, triethylborate, and a triethylphosphorus compound. In one embodiment of this invention, the canister has a capacity of from about 1 to about 50 liters. These canisters may be shipped in approved shipping crates.
Advantageously, the liquid mixture of this invention is stable, and does not undergo transesterification or form by-products during proper storage. Furthermore, this composition does not suffer the depletion effects of the aforementioned TEOS, trimethylborate, and trimethylphosphite mixture. This invention, therefore, provides a single mixture effective in the manufacture of in situ doped borophosphosilicate during semiconductor manufacture, unlike the prior art. This invention thus overcomes the difficulties and problems inherent in the prior art. This invention, moreover, enables use of simplified delivery systems resulting in a reduction in process variables and reduced dependence on calibration of flow controllers, pressures, and efficiency of mixing compared to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
The tetraethylorthosilicate, Si(OC 2 H 5 ) 4 ,employed in this invention is a well known compound which is available commercially. For example, high purity TEOS is available from a variety of sources such as Advanced Delivery and Chemical Systems, Ltd. in Austin, Tex. In the practice of this invention, it is generally desirable to use TEOS at least 95% pure, with 99.99% or more pure TEOS being more preferable.
Triethylborate is also a well known, commercially available material. High purity triethylborate is available from a variety of sources, such as Advanced Delivery and Chemical Systems, Ltd. In the practice of this invention, it is generally desirable to use triethylborate of at least 95% purity, with 99.99% or more pure triethylborate being more preferable.
The triethylphosphorus compounds used in this invention may be any phosphorus compound having ethyl substituents which will lead to in situ doped silicon oxide through use of the composition of this invention. Representative examples of such triethylphosphorus compounds include triethylphosphate and triethylphosphite. Generally, triethylphosphate is more desirable in the practice of this invention, as is triethylphosphorus compounds of at least 95% purity. More desirably, 99.99% or higher purity triethylphosphorus compounds are employed in practice of this invention. High purity triethylphosphite and triethylphosphate are available commercially from a variety of sources, such as Advanced Delivery and Chemical Systems, Ltd.
The composition of this invention may be readily prepared by simple mixing. For instance, exact amounts of TEOS, triethylborate, and triethylphosphorus compound may be sequentially added to a canister. The flow of the components typically effects mixing. If desired, the canister can also be shaken or the like to thoroughly mix the components. Alternatively, the components can be fed concurrently into a canister, so that mixing occurs simultaneous with the components addition to the storage vessel. Likewise, the components can be admixed and then fed to the canister. Since TEOS, triethylborate, and triethylphosphorus compound react with water, it is advisable to handle the components and mixture under dry conditions.
During use, the composition of this invention may be used as the silane source in a conventional deposition apparatus, such as chemical vapor deposition apparatus and low pressure chemical vapor deposition. Generally, deposition of the borophosphosilicate occurs by decomposition of the reactants in a plasma reactor with a heated substrate. By this process, silicon dioxide in situ doped with boron and phosphorus is deposited on a given substrate.
It has been found that there is not a direct correlation between the amount of boron and phosphorus in the multi-component composition to the amounts of boron and phosphorus in the borophosphosilicate produced during use of the composition of this invention. For example, in a Novellus Concept One plasma enhanced CVD system employing a total flow rate of 2.1 grams/minute at 0.50 Watt/cm 2 and 13.56 MHz, it has been found that if the desired percentage of boron and phosphorus in the final product is 3% and 6%, respectively, then the liquid mixture needs to contain 14.9 percent by weight triethylborate (TEB) and 10.04 percent by weight triethylphosphate (TEPO). The liquid mixture thus would have 19.8 mole percent boron and 11.04 mole percent phosphorus. It should be appreciated that the exact proportions of components in the liquid mixture of this invention needed to provide a selected percentage ratio in the resulting borophosphosilicate may vary depending on a number factors, such as reactor design (e.g., differences in final composition may be influenced by reactor design), plasma density (which is a function of RF power and wafer size), pressures, wafer temperature, residence time, and apparatus size. These factors are well known to one of skill in the art, and are readily controlled.
While these factors may affect final composition of the borophosphosilicate, a desired final composition can be readily correlated to a starting liquid mixture by inputting data points to produce a linear regression. Once a linear regression is established, it can be used to determine the molar ratio of the mixture. Likewise, a given final composition can be achieved by varying the individual components until a desired final composition is achieved. Generally, the procedure would involve varying the individual component amounts until the correct molar percentage is achieved, adding the mixture to a canister, installing the canister on a given deposition apparatus, flushing the system, making the depositions, and analyzing the resulting film.
An advantage of the composition of the present invention is the stability of the liquid mixture. Compositions of this invention were subjected to proton nuclear magnetic resonance (nmr) analysis at varying times after preparation of a liquid mixture, with no change or addition to molecular structure having been observed. Similarly, gas chromatography over a three month period of liquid mixtures of this invention showed that the mixture was stable with no by-products being observed.
Representative examples of liquid mixture composition percentages that correspond to selected boron/phosphorus ratios of the borophosphosilicate produced in the above-referenced plasma enhanced CVD system are shown in Table 1 hereinbelow, wherein all percentages are by weight.
The compositions of this invention may optionally include a triethoxyarsenic compound. Alternatively, the triethoxyarsenic compound may be employed alone with TEOS in the absence of TEB and the triethylphosphorus compound. A liquid mixture containing TEOS and triethoxyarsenic compound will form an arsenic silicate glass (“AsSG”). Triethoxyarsenic compounds are well known and are commercially available. Representative examples of such triethoxyarsenic compounds including triethoxyarsenite and triethoxyarsenate. It is desirable to use triethoxyarsenic compound having a purity of at least about 95%, with a purity of at least about 99.99% being more desirable. It is contemplated that liquid mixtures of this invention that contain such arsenic compounds, which are generally highly toxic, will possess various advantages and benefits. For example, TEOS is more volatile than triethoxyarsenate, and since triethoxyarsenate would be a minor component of the liquid mixture, it is expected that TEOS, for example, will preferentially evaporate from the mixture relative to triethoxyarsenate. Hence, it is believed that the liquid mixture will be less of a hazard, based on volatile organic content of air exposed to the mixture, than the arsenate alone. It is expected that such liquid mixtures will enable the semiconductor fabrication industry to manufacture AsSG from a single, liquid mixture. If employed, the triethoxyarsenic compound may be added in an amount to so that the triethoxyarsenic compound makes up from about 0.1 percent by weight to about 10 percent by weight of the liquid mixture, based on the total weight of the liquid mixture.
It is contemplated that it may be possible to employ octomethylcyclotetrasilane (OMCATS) in combination with, or in place of, TEOS as the silicon source with alternative dopants.
The following examples are illustrative of this invention and are not intended to be limiting as to the scope of the invention or claims hereto. Unless otherwise specified, all percentages are by weight.
EXAMPLES 1-13
Preparation of Three-Component Liquid Mixtures and Manufacture of Borophosphosilicate
After measuring appropriate amounts in a quartz bubbler under anhydrous conditions, TEOS, TEB, and TEPO were each sequentially flowed into a stainless steel canister in the percentages described in Table 1. The final composition of the borophosphosilicate produced by plasma enhanced CVD at 13.56 MHz and 0.5 Watt/cm 2 and a flow rate equal to 2.1 grams/minute using each of the compositions is set forth.
TABLE 1
LIQUID MIXTURE (wt %)
B/P (wt %/wt %) RATIO IN
Example
TEOS
TEB
TEPO
BOROPHOSPHOSILICATE
1
76.7
16.8
6.41
3.35/3.65
2
75.3
15.2
9.55
1.7/3.5
3
73.2
19.9
6.87
3.9/4.3
4
73.3
19.9
6.76
3.9/4.0
5
64.8
28.7
6.48
5.49/3.56
6
71.3
24.5
4.15
5.22/2.87
7
70.77
24.5
4.7
5.0/2.9
8
72.97
22.7
4.31
4.9/2.5
9
60.0
28.5
11.5
(4.6 to 6.5)/(5.1 to 6.1)
10
68.2
23.5
8.26
4.56/5.14
11
70.3
21.7
8.03
4.95/5.0
12
71.9
20.6
7.53
4.6/4.55
12
74.7
14.9
10.41
2.86/6.32
The liquid mixtures employed in Examples 1-13 were analyzed by NMR and found to be stable, with no change or addition to molecular structure being observed. Likewise, gas chromatography analysis over a three month period revealed stable mixtures and no observed by-products. Thus, these compositions have significantly improved properties over prior compositions, such as a TEOS, TEB, and TEPO composition. These mixtures were added to stainless steel canisters (2000 gram fill) prior to use.
|
This invention concerns a stable composition useful in the manufacture of semiconductors, comprising a liquid mixture of: octomethylcylcotetrasilane and a triethoxy arsenic compound.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of DE 103 48 841.3 filed Oct. 21, 2004, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to a device with at least two parts rotatable in relation to one another, such as a gear mechanism, especially for a multiaxial industrial robot, wherein a seal is arranged between the parts rotatable in relation to one another.
BACKGROUND OF THE INVENTION
[0003] Handling gear in the form of multiaxial industrial robots, as they are nowadays used for many industrial applications, usually have a plurality of parts that are rotatable in relation to one another. To prevent, on the one hand, dirt, for example, dust, or moisture from penetrating into the interior of the robot at the necessarily open interfaces of such parts rotatable in relation to one another and, on the other hand, lubricant fumes, abraded particles or the like from being able to be released from the robot into the environment, seals are usually arranged at the interfaces in such devices.
[0004] A device of this type in conjunction with a multiaxial industrial robot has been known, for example, from EP 0 934 805 A2. The subject of the document has a plurality of axes and housing parts that are rotatable in relation to one another, and a seal each is arranged between these in the form of a sealing ring. Moisture and dust are to be prevented by means of the seals from penetrating into the robot from the outside, so that the robot can be used without a risk of damage to its inner components in the food-processing industry as well.
[0005] The fact that both moisture and contaminants can enter the robot and substances, such as lubricant fumes or abraded particles can escape from the robot into the ambient space, which may lead to considerable problems with corresponding cost consequences especially in the food industry because of contamination of the foods being processed even in case of a slight damage to one of the seals, shall be considered, in particular, to be a drawback here.
SUMMARY OF THE INVENTION
[0006] The basic object of the present invention is to improve a device of the type described in the introduction such that it can also be used safely in an environment with risk for contamination and inner components of the device are protected from environmental effects at the same time.
[0007] This object is accomplished in a device of the type described in the introduction by an additional seal being arranged between the parts rotatable in relation to one another. The second seal can thus also assume the function of the other seal in case of failure of one of the seals. A sealing means, which reliably prevents pollutants from entering the device and contaminating substances from escaping into a working area of the device, is thus formed according to the present invention.
[0008] Provisions are made in a variant of the device according to the present invention for the seals to have an essentially ring-shaped design, in which case they may be preferably arranged concentrically. Especially simple and efficient seals can thus be obtained in case of parts that are rotatable in relation to one another and therefore usually have a rotationally symmetrical design.
[0009] Provisions are made within the framework of an especially preferred embodiment of the device according to the present invention for the first part to have on its front side facing the second part a first recess and a second recess, which are engaged by corresponding, complementary first and second projections of the second part. To achieve reliable sealing between the parts rotatable in relation to one another in such a device, a seal is advantageously arranged between a limiting surface of the first projection and a limiting surface of the first recess, and a seal is arranged between the limiting surface of the second recess and the second projection.
[0010] To obtain a simple geometry of the sealing surfaces, the first projection and the first recess have an essentially regular cylindrical shape in an extremely preferred variant of the present invention. For the same reason, the second projection and the second recess may have an essentially ring-shaped design. The second projection and the second recess may concentrically surround the first projection and the first recess, respectively.
[0011] In a variant of the device according to the present invention, an essentially closed gap, to which pressure can advantageously be admitted, is formed between the seals. It is thus possible, on the one hand, to support the seals from the inside during cleaning operations, e.g., by means of a high-pressure cleaning means, in order to prevent detergents from entering the device. On the other hand, the space between the seals can thus be rinsed with a fluid, such as disinfectant solution, in order to thus prevent microorganisms from growing in the interior of the device and a subsequent contamination of the environment of the device.
[0012] Provisions are made in a preferred variant of the device according to the present invention for one of the seals to be designed as a sealing lip that is in contact with one part from the outside, which advantageously has a concave arch against an external space of the device, so that the entry of substances into the device is made difficult especially during the cleaning operations and dirt spaces are generally prevented from forming. To guarantee the sealing action especially of the inner seal when pressure is admitted into the gap, provisions may, furthermore, be made for one of the seals to have a concave profile at least on its side facing away from the gap. To further improve the possibility of using a device according to the present invention for applications involving a risk for contamination, such as in the food industry, the seals are preferably made of PTFE (polytetrafluoroethylene) or a comparable pollutant-reducing material, for example, a fluorinated elastomer, ethylene-propylene-diene rubber (EPDM, likewise an elastomer) or polyoxymethylene (POM; a thermoplastic).
[0013] Provisions are made in an extremely preferred, concrete variant of the device according to the present invention for one of the parts rotatable in relation to one another to be designed as a housing for a gear mechanism, especially for a multiaxial industrial robot, and for the other part to exit from same, especially in the form of a drive shaft or a power take-off shaft.
[0014] Other properties and advantages of the present invention will appear from the following description of exemplary embodiments on the basis of the drawings. 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 disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side view of a multiaxial industrial robot;
[0016] FIG. 2 is a schematic view of the device according to the present invention;
[0017] FIG. 3 is a detailed, cutout sectional view of a first embodiment of the device according to the present invention;
[0018] FIG. 4 is a detailed, cutout sectional view of a second embodiment of the device according to the present invention;
[0019] FIG. 5 is a detailed, cutout view of another embodiment of the device according to the present invention; and
[0020] FIG. 6 is a detailed, cutout view of another embodiment of the device according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 shows a rear view of a multiaxial industrial robot R. At least in its joint areas between the frame R. 1 and the rocker R. 2 or the rocker and arm R. 3 , the robot R has devices 1 , 1 ′ according to the present invention with parts 2 , 3 and 2 ′, 3 ′ that are rotatable in relation to one another.
[0022] FIG. 2 shows a schematic sectional view of a device 1 according to the present invention with a first part 2 and a second part 3 , which are rotatable in relation to one another around an axis A of the device 1 (arrow P in FIG. 2 ). The parts 2 , 3 shown may be, for example, a gear mechanism housing 2 and a drive or power take-off shaft 3 in a multiaxial industrial robot (not shown).
[0023] On its front side 2 . 1 facing the part 3 , the first part 2 has a first recess 2 . 2 and a second recess 2 . 3 , which engage corresponding, complementary first and second projections 3 . 1 , 3 . 2 on a front side 3 . 3 of the second part 3 .
[0024] Furthermore, the first projection 3 . 1 and the first recess 2 . 2 have an essentially regular cylindrical shape according to FIG. 2 , while the second projection 3 . 2 and the second recess 2 . 3 are essentially ring-shaped. The second projection 3 . 2 and the second recess 2 . 3 concentrically surround the first projection 3 . 1 and the first recess 2 . 2 , respectively, in relation to the axis A.
[0025] A first ring-shaped seal 4 is arranged between an outer limiting surface 3 . 4 of the first projection 3 . 1 and an inner limiting surface 2 . 4 of the first recess 2 . 2 . A second, likewise ring-shaped seal 5 is arranged concentrically with the seal 4 between an inner limiting surface 2 . 5 of the second recess 2 . 3 and an outer limiting surface 3 . 5 of the second projection 3 . 2 . According to the embodiment shown in FIG. 2 , an essentially concentric—albeit optionally axially offset—arrangement of the seals 4 , 5 is obtained in relation to the axis A of the device 1 .
[0026] Furthermore, the first projection 3 . 1 and the first recess 2 . 2 have an essentially regular cylindrical shape according to FIG. 2 , while the second projection 3 . 2 and the second recess 2 . 3 are essentially ring-shaped. The second projection 3 . 2 and the second recess 2 . 3 surround the first projection 3 . 1 and the first recess 2 . 2 , respectively, concentrically in relation to the axis A.
[0027] Furthermore, it can be determined from FIG. 2 that an essentially closed gap 6 , which has an approximately S-shaped cross section in case of the special embodiment and arrangement of the projections 3 . 1 , 3 . 2 and recesses 2 . 2 , 2 . 3 as shown, is formed between the seals 4 , 5 .
[0028] In case of the above-mentioned design of the first part 2 as a housing part and of the second part 3 as a drive shaft or power take-off shaft of a gear mechanism, both seals 4 , 5 are located according to FIG. 2 between the usually stationary housing and the drive shaft or power take-off shaft which rotates relative thereto. In case of such an embodiment, the inner seal 4 may be a usual gear mechanism seal known to the person skilled in the art. The outer seal 5 provided additionally is preferably made of a material compatible with foods, for example, PTFE, EPDM, POM or a fluorinated elastomer. According to the view shown in FIG. 2 , the inner seal 4 retains a gear mechanism lubricant and thus prevents contamination of the environment, while the outer seal 5 prevents water and dirt from entering the device 1 according to the present invention. The gap 6 located between the seals 4 , 5 supports both seals, while in case of failure of one of the seals 4 , 5 , the respective other seal assumes the protective function of the other seal. The device 1 thus created according to the present invention is consequently especially suitable for use in the food-processing industry because of its special sealing means 4 , 5 .
[0029] FIGS. 3 through 6 show additional concrete embodiments of the device according to the present invention in a detailed form, corresponding components of the device being designated by the same reference numbers for comparison with the schematic view in FIG. 2 .
[0030] According to FIG. 3 , the outer seal 5 is designed as a simple peripheral sealing lip 5 . 1 , which is designed, e.g., arched concavely against an outer space 7 , for example, a working space of a robot, such that dirt spaces are generally prevented from forming, and the sealing lip is in contact with the outer limiting surface 3 . 5 of the second part 3 of the device 1 . Good sealing action is achieved in this manner even in case of the action of pressure on the seal 5 from the outside, for example, when the device 1 is cleaned by means of a cleaning device. The sealing lip 5 . 1 is arranged according to FIG. 3 between an inner limiting surface 2 . 5 of the outer recess 2 . 3 and a ring-shaped insert 2 . 6 arranged in the recess 2 . 3 and is held by means of a ring-shaped holding means 2 . 7 arranged in a peripheral groove 2 . 6 a of the insert 2 . 6 .
[0031] The inner seal 4 is designed in the object according to FIG. 3 as a ring-shaped seal with an essentially U-shaped profile and is arranged such that on its side 4 . 1 facing away from the gap 6 it has a profile, for example, a concave profile, by which dirt spaces are prevented from forming. To receive the seal 4 , the projection 3 . 1 of the rotating (driven) part 3 has a peripheral recess 3 . 6 in its outer limiting surface 3 . 4 .
[0032] According to the embodiment of a device according to the present invention as shown in FIG. 4 , the outer seal 5 is provided with two essentially mutually parallel sealing lips 5 . 1 , 5 . 1 ′ and is arranged between the first part 2 and the second part 3 without an insert 2 . 6 ( FIG. 3 ). The inner seal 4 has a double U-shaped profile in this embodiment, and free legs 4 . 2 a - d of the inner seal 4 are arranged such that the seal has a concave profile both on its side facing the gap 6 and on its respective sides 4 . 1 and 4 . 2 facing away from the gap 6 .
[0033] Unlike in FIG. 3 , the insert 2 . 6 is not of a one-piece design in the object according to FIG. 6 , but is provided in the area of its outer front side 2 . 6 b with a ring-shaped attachment 2 . 6 c having a wedge-shaped cross section, via which the arch can be adapted to the sealing lip 5 . 1 . For reasons of clarity, not all reference numbers are shown in FIG. 5 as well as in FIG. 6 (cf. FIGS. 3 and 4 ).
[0034] FIG. 6 shows essentially a device 1 according to the present invention corresponding to FIG. 3 , but with an inner seal 4 according to FIG. 4 .
[0035] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
Appendix
[0000] List of Reference Numbers
[0000]
1 , 1 ′ Device
2 , 2 ° First part, housing
2 . 1 Front side
2 . 2 Recess
2 . 3 Recess
2 . 4 Limiting surface
2 . 5 Limiting surface
2 . 6 Insert
2 . 6 a Groove
2 . 6 b Attachment
2 . 7 Holding means
3 , 3 ′ Power take-off
3 . 1 Projection
3 . 2 Projection
3 . 3 Front side
3 . 4 Limiting surface
3 . 5 Limiting surface
3 . 6 Recess
4 Seal
4 . 1 Side
4 . 2 a - d Free leg
5 Seal
5 . 1 , 5 . 1 ′ Sealing lip
6 Gap
7 Outer area, environment
A Axis
P Rotation
R Robot
R. 1 Frame
R. 2 Rocker
R. 3 Arm
|
A device ( 1 ) with at least two parts ( 2, 3 ) rotatable in relation to one another, such as a gear mechanism, especially for a multiaxial industrial robot, in which a seal ( 4 ) is arranged between the parts ( 2, 3 ) rotatable in relation to one another, is wherein at least one additional seal ( 5 ) is arranged between the parts ( 2, 3 ) rotatable in relation to one another. The device ( 1 ) thus has a sealing arrangement ( 4, 5 ), which reliably prevents both the entry of water and/or dirt into the device and the escape of potentially contaminating substances from the device into the environment. The device ( 1 ) can thus also be used in areas that are at risk for contamination, such as in the food-processing industry.
| 1
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. Ser. No. 10/834,974, filed on Apr. 30, 2004. This application, in its entirety, is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a mascara brush, and more particularly, to a mascara brush, wherein an application portion as a means for applying a mascara liquid to eyelashes and a comb for arranging the eyelashes are simultaneously formed on a single brush rod so that the application of the mascara liquid to the eyelashes and the arrangement of the eyelashes can be performed at one time.
[0004] 2. Description of the Prior Art
[0005] Mascara is one of cosmetics used by women to apply mascara liquids of various colors to their eyelashes so that their eyes can look better in an esthetic sense. Generally, as shown in FIG. 18 , a mascara brush 100 comprises a container 150 for containing a mascara liquid, a grip 160 for opening and closing the container 150 , a brush rod 120 extending downwardly from the grip 160 , and a brush part 130 formed at the brush rod 120 . The mascara liquid is used in such a manner that the brush part 130 is smeared with the mascara liquid through engagement or disengagement of the grip 160 to or from the container 150 .
[0006] Particularly, depending on the length and configuration of the bristles, the mascara brush 100 constructed as above is manufactured to be adapted to various functions such as volume-up (effect of allowing eyelashes to be seen abundantly), curling (effect of upwardly curling distal ends of eyelashes), long lash (effect of allowing eyelashes to appear longer) and clean (effect of preventing eyelashes from being entangled) for eyelashes.
[0007] As shown in FIG. 18 , the conventional mascara brush that has been typically used is manufactured in such a manner that bristles 131 of the brush part 130 with a generally constant length are disposed between two stands of wires and the wires are then twisted several times so that the brush part 130 can have a cross section in the form of any of various shapes including circular, triangular and sectorial shape about a wire shaft 121 . The effects of volume-up, curling, long lash and clean can be obtained with respect to the respective shapes of the cross section of the brush part 130 .
[0008] The basic function of the mascara brush is to evenly apply a viscous mascara liquid to eyelashes and to appropriately comb the eyelashes by means of the brush part so that the eyelashes are not entangled. Since the bristles 131 extend radially along a helical path due to the twisting of the wires in the conventional mascara brush 100 , a great deal of mascara liquid can be accommodated between the respective bristles 131 . Thus, the conventional mascara brush can make the eyelashes appear voluminous. However, eyelashes often become entangled due to the viscosity of the mascara liquid. Accordingly, there is inconvenience in that the eyelashes should be arranged using an additional arranging instrument, or make-up application should be performed again after the excess mascara liquid is removed.
[0009] A mascara brush 200 for solving the entanglement phenomenon of eyelashes of the previous mascara brush, as shown in FIG. 19 , comprises a brush rod 220 of which a lower end has a diameter smaller than that of an upper end thereof, and a brush part 230 that is formed at a side surface of the lower end of the brush rod and has bristles 231 formed by a separate manufacturing apparatus from the same synthetic resin material as the brush rod 220 and then fixed to the brush rod 220 . The bristles 231 are arranged longitudinally in a line on the side surface of the lower end of the brush rod 220 to take the shape of a linear comb. Thus, when a mascara liquid is applied to eyelashes, it is applied to the eyelashes while permeating through the eyelashes due to the combing of the linear brush part 230 . Accordingly, the effects of clean and long lash can be obtained.
[0010] Meanwhile, the bristles 231 of the mascara brush 200 are formed of a material similar to a material for the brush rod 220 , which is a synthetic resin such as polyamide. The bristles 231 are completed by slitting a mass of the synthetic resin constructing the brush part 230 into fine strands. In view of properties of the synthetic resin, however, the bristles 231 cannot be formed finely to such as extent as the bristles 131 of the conventional mascara brush 100 shown in FIG. 16 . Further, since the wide spacing of the respective bristles 231 deteriorates their capability to accommodate a mascara liquid, it is difficult to apply the mascara liquid in case of tufty or long eyelashes. Moreover, although the linearly arranged bristles 231 applies the mascara liquid to eyelashes in such a manner that they comb the eyelashes upon application of the mascara liquid, thereby preventing the entanglement phenomenon of the eyelashes, there is a problem in that the effects of volume-up and curling of the eyelashes are deteriorated.
SUMMARY OF THE INVENTION
[0011] The present invention is conceived to solve the aforementioned problems in the prior art. Accordingly, an object of the present invention is to provide a mascara brush, wherein a single brush rod of the mascara brush is formed with both an application brush part with an application portion for applying a mascara liquid to eyelashes and an arrangement brush part with a comb for arranging the eyelashes in order to simultaneously perform the application of the mascara liquid and arrangement of the eyelashes, thereby conveniently imparting the effects of clean, long lash and curling to the eyelashes through a single process, the structure of the mascara brush is simplified so that a manufacturing process can be relatively simplified, and stability in use can be obtained due to the securely coupled state.
[0012] According to the present invention for achieving the object, there is provided a mascara brush, comprising an application brush part with an application portion formed on an outer circumferential surface of a rod thereof to apply a mascara liquid to eyelashes; and an arrangement brush part including a fixing stand coupled to the application brush part, and a comb formed on an outer peripheral surface of the fixing stand. The application brush part is formed with a cutaway portion by longitudinally cutting away a section of the application portion, and the comb is placed in the cutaway portion so that the arrangement brush part can be integrated with the application brush part.
[0013] The rod of the application brush part may be constructed by twisting parts of a metal wire, and the application portion may be fixedly formed by interposing a plurality of bristles between the parts of the metal wire and twisting the parts of the metal wire.
[0014] The rod of the application brush part may be injection molded from a synthetic resin such that the application portion is formed on the outer circumferential surface of the rod.
[0015] The fixing stand may be sized to correspond to the cutaway portion of the application brush part, an upper end of the fixing stand may be formed with a fitting hole into which the rod is fixedly inserted and a lower end of the fixing stand may be formed with a fitting recess into which a distal end of the rod on the side of the application portion is fixedly inserted, and the comb may be formed on a side surface of the fixing stand in a longitudinal direction of the fixing stand.
[0016] The fixing stand may be formed to take the shape of a cylinder and formed with a central insertion bore longitudinally therethrough so that the rod can be inserted into the insertion bore, a lower end of the fixing stand may be formed with a fitting recess into which a distal end of the rod on the side of the application portion is fixedly inserted, both sides of the fixing stand may be perforated to have open windows such that existing sections of the application portion of the application brush part protrude outwardly through the windows, and the comb may be formed on a side surface of the fixing stand in a longitudinal direction of the fixing stand.
[0017] A section of the application portion fixed at the distal end of the rod on the side of the application portion may be removed and a ring may be formed to be exposed at the distal end of the rod.
[0018] A distal end of the rod with the application portion injection molded thereon may be performed to form a ring.
[0019] The arrangement brush part coupled to the application brush part may comprise the fixing stand for fixing and supporting the application brush part, and the comb formed on a side surface of the fixing stand, the fixing stand may be sized to correspond to the cutaway portion of the application brush part, an upper end of the fixing stand may be formed with a fitting hole into which the rod is fixedly inserted, and a lower end of the side surface may be formed with a protruding, coupling piece adapted to be fixedly inserted into the ring of the rod.
[0020] The arrangement brush part coupled to the application brush part may comprise the fixing stand for fixing and supporting the application brush part, and the comb formed on a side surface of the fixing stand, the fixing stand may be formed to take the shape of a tube and formed with a central insertion bore longitudinally therethrough so that the rod of the application brush part can be inserted into the insertion bore, both sides of the fixing stand may be perforated to have open windows such that existing sections of the application portion of the application brush part protrude outwardly through the windows, and a lower end of the side surface may be formed with a protruding, coupling piece adapted to be fixedly inserted into the ring of the rod.
[0021] The cutaway portion may be formed in an angular range of 30 to 120 degrees about the center of the cross section of the application brush part.
[0022] The cutaway portions may be formed by cutting away lateral side sections of the application portion that are symmetric with each other with respect to the cross section of the application brush part.
[0023] One or more columns of combs may be formed on the arrangement brush part in a longitudinal direction of the fixing stand.
[0024] A plurality of columns of combs are formed on the fixing stand in a zigzag manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
[0026] FIG. 1 is a front view of a mascara brush according to a first embodiment of the present invention;
[0027] FIG. 2 is a front view showing a state where an application brush part and an arrangement brush part of the mascara brush shown in FIG. 1 are separated from each other;
[0028] FIG. 3 is a bottom view of the application brush part of FIG. 2 ;
[0029] FIG. 4 is a perspective view showing that a plurality of columns of combs are formed at the arrangement brush part of FIG. 2 ;
[0030] FIG. 5 is a bottom view showing a state where the application brush part of FIG. 2 and an arrangement brush part with a column of comb are coupled to a brush rod of the mascara brush;
[0031] FIG. 6 is a bottom view showing a state where the application brush part of FIG. 2 and an arrangement brush part with a plurality of columns of combs are coupled to a brush rod of the mascara brush;
[0032] FIGS. 7 a and 7 b are front and bottom views of an application brush part according to a second embodiment of the present invention, respectively, wherein cutaway portions are formed symmetrically;
[0033] FIGS. 8 a and 8 b are front and bottom views of an arrangement brush part according to the second embodiment of the present invention, respectively, wherein a fixing stand having a configuration corresponding to that of the application brush part with the cutaway portions formed symmetrically is provided;
[0034] FIGS. 9 a and 9 b are front and bottom views showing a state where the application brush part of FIG. 7 a and the arrangement brush part of FIG. 8 a are coupled to each other, respectively;
[0035] FIGS. 10 a, 10 b and 10 c are a front view, a side view and a sectional view through line A-A, respectively, showing an application brush part according to a third embodiment of the present invention;
[0036] FIGS. 11 a and 11 b are a front view and a sectional view through line B-B, respectively, showing an arrangement brush part according to the third embodiment of the present invention;
[0037] FIGS. 12 a and 12 b are a front view and a sectional view through line C-C, respectively, showing a state where the application brush part and the arrangement brush part according to the third embodiment of the present invention are coupled to each other;
[0038] FIGS. 13 a and 13 b are a front view and a sectional view through line A′-A′, respectively, showing an application brush part according to a fourth embodiment of the present invention;
[0039] FIGS. 14 a and 14 b are a front view and a sectional view through line B′-B′, respectively, showing an arrangement brush part according to the fourth embodiment of the present invention;
[0040] FIGS. 15 a and 15 b are a front view and a sectional view through line C′-C′, respectively, showing a state where the application brush part and the arrangement brush part according to the fourth embodiment of the present invention are coupled to each other;
[0041] FIGS. 16 a, and 16 b and 16 c are a front view and bottom views showing application brush parts according to further embodiments of the present invention;
[0042] FIGS. 17 a, and 17 b and 17 c are a front view and bottom views showing that a ring portion is formed at a lower end of a rod of the application brush part of FIG. 16 a; and
[0043] FIGS. 18 and 19 are perspective views of conventional mascara brushes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Hereinafter, preferred embodiments of a mascara brush of the present invention will be described in detail with reference to the accompanying drawings.
[0045] FIG. 1 is a view showing a mascara brush according to a first embodiment of the present invention in a disengaged state. The mascara brush 1 comprises a container 5 for containing a mascara liquid, a grip 6 for opening and closing the container 5 , a brush rod 2 extending downwardly from the grip 6 , and an application brush part 3 and an arrangement brush part 4 formed at a lower end of the brush rod 2 .
[0046] The brush rod 2 fixed to the grip 6 is in the form of a rod which has a predetermined length such that it can be inserted into the container 5 and the application brush part 3 can be then smeared with the mascara liquid, and has a diameter smaller than that of a mouth of the container 5 such that it can pass through the mouth of the container 5 . At the lower end of the brush rod 2 , a rod 21 with the application brush part 3 fixed thereto is coupled to a fixing stand 40 formed with the arrangement brush part 4 .
[0047] FIG. 2 is a front view showing a state where the application brush part and the arrangement brush part are separated from each other.
[0048] The application brush part 3 is a means for receiving the mascara liquid and applying it to eyelashes. The application brush part 3 is constructed by interposing a plurality of bristles having a constant length between and perpendicularly to two parts of a metal wire folded at the center thereof and spirally twisting the two wire parts several times. Thus, the bristles are fixed radially to the rod 21 formed through the twisting of the wire parts, thereby forming an application portion 7 .
[0049] Further, as shown in FIG. 3 , a side surface of the application brush part 3 is formed longitudinally (perpendicularly to the cross section of the application brush part 3 ) with a cutaway portion 31 by cutting away a section of the application portion 7 that is fixed to the wire shaft constructing the rod 21 . At this time, the cutaway portion 32 is formed by longitudinally cutting away a section of the application portion 7 within an angular range of about 30 to 120 degrees about the center of the cross section of the application brush part 3 .
[0050] Then, the application brush part 3 constructed as above is fixedly coupled to the lower end of the brush rod 2 to be integrated with the brush rod 2 .
[0051] The arrangement brush part 4 shown in FIG. 2 is a means for arranging the eyelashes smeared with the mascara liquid by the application brush part 3 , and has a comb 8 protruding from an outer surface of the fixing stand 40 .
[0052] The fixing stand 40 is to fix the comb 8 to the cutaway portion 31 of the application brush part 3 . The longitudinal length of the fixing stand 40 is identical with or slightly larger than that of the rod 21 extending the lower end of the brush rod 2 . Upper and lower ends of the fixing stand 40 are formed with upper and lower flanges that extend in a direction perpendicular to a side surface 41 corresponding to the longitudinal length of the fixing stand 40 and have a diameter identical with that of the brush rod 2 .
[0053] The upper flange of the fixing stand 40 is formed with a fitting hole 42 through which the rod 21 is inserted so that the fixing stand 40 is integrated with the application brush part 3 . The lower flange of the fixing stand 40 is formed with a fitting recess 43 into which a distal end of the rod 21 on the side of the application portion 7 is fixedly inserted when the rod 21 inserted into the fitting hole 42 is lowered. Further, since the comb 8 formed on the side surface 41 of the fixing stand 40 is placed in the cutaway portion 31 formed in the application portion 7 of the application brush part 3 , the cross section of the side surface of the fixing stand 40 takes the shape of a sector with a central angle of about 30 to 120 degrees corresponding to the shape of the cutaway portion 31 . The fixing stand 40 is in the form of “ ” as a whole.
[0054] The comb 8 has one or more teeth thereof protruding vertically from the side surface 41 of the fixing stand 40 in order to comb the eyelashes. The teeth of the comb 8 are formed in a line to protrude vertically from the side surface of the fixing stand 45 over a length similar to that of the application portion 7 fixed to the rod 21 of the application brush part 3 . Here, the teeth of the comb 8 are injection molded using a precision mold from the same material as the fixing stand 40 , i.e. natural resin, synthetic resin including polyamide, or the like, so that they can be formed to be thicker and more robust than the application portion 7 of the application brush part 3 . The respective teeth of the comb 8 are formed in a line at an interval of about 0.1 to 1 mm. Accordingly, the arrangement brush part 4 takes the shape of a linear comb.
[0055] As for the comb 8 of the arrangement brush part 4 , it is preferred that one or more columns of combs 8 be formed perpendicularly to the side surface 41 of the fixing stand 40 , as shown in FIG. 4 . Moreover, teeth of a column of comb 8 and teeth of the next column of comb may be formed to be in the same horizontal planes or to be staggered in a zigzag manner.
[0056] To fix the arrangement brush part 4 constructed as above to the application brush part 3 , the fitting hole 42 of the fixing stand 40 is fitted around the rod 21 , the fixing stand 40 is then adjusted in its position such that the side surface 41 of the fixing stand 40 is placed in the cutaway 32 of the application brush part 3 , and the fitting recess 43 of the fixing stand 40 is fitted around the distal end of the rod 21 on the side of the application portion 7 . Consequently, the fixing stand 40 and the rod 21 are coupled to each other.
[0057] Here, since the application portion 7 does not extend up to the distal end of the rod 21 , the distal end of the rod 21 is press-fitted into the fitting recess 43 and the rod 21 is then fixedly coupled to the fixing stand 40 by means of various methods including adhesive bonding, thermal bonding and the like.
[0058] As described above, both the application brush part 3 and the arrangement brush part 4 are coupled to the single brush rod 2 . Thus, the application brush part 3 is formed at a side of the brush rod 2 and the arrangement brush part 4 is formed at the other side of the brush rod 2 so that the mascara brush 1 can have an actiniform configuration as a whole.
[0059] Further, lower portions of the application and arrangement brush parts 3 and 4 of the mascara brush 1 are cut slantingly toward their distal ends to more easily facilitate access to short eyelashes located at either side of the eyelid.
[0060] Therefore, when the mascara brush 1 constructed as above is smeared with the mascara liquid and then used, the application brush part 3 with the application portion 7 receives a large amount of mascara liquid. Thus, when the mascara liquid is applied to the eyelashes by the application brush part 3 formed at a side of the mascara brush 1 , the application portion 7 of the application brush part 3 comes into contact with the eyelashes and applies the mascara liquid to the eyelashes, thereby imparting volume-up effect to the eyelashes. Then, the eyelashes are arranged using the arrangement brush part 4 formed in the form of a comb at the other side of the mascara brush 1 . The teeth of the comb 8 deeply penetrate between the respective eyelashes to prevent entanglement of the eyelashes and simultaneously support the eyelashes throughout the use of the arrangement brush part. Therefore, the effects of volume-up, long lash, curling and clean are exhibited.
[0061] At this time, since the linear comb 8 formed at the arrangement brush part 4 is also smeared with the mascara liquid, the effects of long lash, curling and clean can be imparted to the eyelashes even when the mascara liquid is applied to the eyelashes using only the arrangement brush part 4 .
[0062] Moreover, when the mascara brush 1 having the arrangement brush part 4 with the plurality of columns of combs 8 is used, the plurality of staggered columns of combs 8 more easily penetrate between the eyelashes to apply the mascara liquid to the eyelashes. Therefore, even when only the arrangement brush part 4 formed with the plurality of columns of combs 8 is used, the effects of volume-up, long lash, curling and clean can be imparted to the eyelashes.
[0063] FIGS. 7 a and 8 a show a second embodiment of the present invention.
[0064] An application brush part 3 of the second embodiment is constructed by interposing a plurality of bristles having a constant length between and perpendicularly to two parts of a wire folded at the center thereof and spirally twisting the two wire parts a certain number of times, as described above. Thus, an application portion 7 thus formed is fixed to the rod 21 formed through the twisting of the wire parts.
[0065] As shown in FIGS. 7 a and 7 b, the application brush part 3 is provided with cutaway portions 32 formed by longitudinally cutting away some sections of the application portion 7 fixed to the rod 21 symmetrically with respect to the cross section of the application brush part 3 . Thus, the application portion 7 of the application brush part 3 has a symmetric configuration.
[0066] That is, in view of the four directions in the cross section of the application brush part 3 , north and south sections of the application portion 7 of the application brush part 3 are cut away in a symmetric manner to form the cutaway portions 32 . Thus, only east and west sections of the application portion 7 except the cutaway portions 32 symmetrically remain in the application brush part 3 .
[0067] As shown in FIGS. 8 a and 8 b, an arrangement brush part 4 that serves as a means for arranging eyelashes smeared with the mascara liquid when coupled to the application brush part 3 has combs 8 protruding outwardly from a side surface 51 of a fixing stand 50 .
[0068] The fixing stand 50 takes the shape of a cylinder and is formed with a central insertion bore 52 longitudinally therethrough so that the rod 21 of the application brush part 3 can be inserted into the insertion bore 52 to cause the fixing stand to be coupled to the application brush part 3 . In order to fix the rod 21 , a lower end of the fixing stand 50 is formed with an insertion recess 53 into which the distal end of the rod 21 on the side of the application portion 7 is fixedly inserted. Further, the side surface 51 of the fixing stand 50 is perforated symmetrically to have open windows 54 with a predetermined size such that when the fixing stand is coupled to the application brush part 3 with the cutaway portions 32 symmetrically formed therein, the existing sections of the application portion 7 of the application brush part 3 protrude outwardly through these windows.
[0069] That is, in view of the four directions in the cross section of the fixing stand 50 , the open windows 54 of the fixing stand 50 are formed symmetrically to correspond to the east and west sections of the application portion 7 of the application brush part 3 , and the combs 8 are formed symmetrically on north and south regions of the side surface 51 of the fixing stand 50 .
[0070] Therefore, in order to couple the arrangement brush part 4 to the application brush part 3 , the insertion bore 52 of the fixing stand 50 is fitted around the rod 21 with the application portion 7 formed thereon, and at the same time, the cutaway portions 32 of the application brush part 3 are placed at closed regions of the side surface 51 of the fixing stand 50 while the existing sections of the application portion 7 of the application brush part 3 are placed in the open windows 54 of the fixing stand 50 . Then, the distal end of the rod 21 on the side of the application portion 7 is inserted into the insertion recess 53 of the fixing stand 50 to couple the fixing stand 50 and the rod 21 to each other.
[0071] Accordingly, both the application brush part 3 and the arrangement brush part 4 are provided on the single brush rod 2 . As shown in FIGS. 9 a and 9 b, the existing sections of the application portion 7 of the application brush part 3 are placed symmetrically in the east and west directions of the brush rod 2 , and the combs 8 of the arrangement brush part 4 are placed symmetrically in the north and south directions of the brush rod 2 . When the mascara brush 1 with the integrally formed application and arrangement brush parts 3 and 4 is used for applying the mascara liquid to the eyelashes, the effects of volume-up, long lash, curling and clean can be imparted to the eyelashes.
[0072] FIGS. 10 a and 11 a are front views showing an application brush part 3 and an arrangement brush part according to a third embodiment of the present invention in a decoupled state, respectively. Although the brush parts of this embodiment are substantially identical with those shown in FIG. 2 in view of their configurations, the configurations of lower ends thereof are different from each other.
[0073] FIG. 10 a is a front view of the application brush part, FIG. 10 b is a side view of FIG. 10 a, and FIG. 10 c is a sectional view taken along line A-A of FIG. 10 a.
[0074] The application brush part 3 is constructed by interposing a plurality of bristles between two parts of a wire folded at the center thereof and spirally twisting the two wire parts several times. Thus, an application portion 7 consisting of the bristles is fixed to the rod 21 formed through the twisting of the wire parts. Further, the application brush part 3 is formed longitudinally with a cutaway portion 31 by cutting away a section of the application portion 7 within an angular range of 30 to 120 degrees in the cross section of the application brush part 3 .
[0075] A section of the application portion 7 fixed to a lowest end of the rod 21 through the twisting of the wire parts is removed so that a ring 22 can be exposed at the lowest end of the rod 21 . With the ring 22 , the application brush part 4 to be described later is coupled to the application brush part 3 .
[0076] FIG. 11 a is a front view of the application brush part, and FIG. 11 b is a sectional view taken along line B-B of FIG. 11 a.
[0077] The arrangement brush part 4 comprises a “ / -shaped ” fixing stand 80 , and a comb 8 formed on a side surface 81 of the fixing stand 80 .
[0078] The side surface 81 defining the longitudinal length of the fixing stand 80 has a length identical with or slightly shorter than that of the rod 21 . An upper flange extending from the side surface 81 in a direction perpendicular thereto is formed with a fitting hole 82 into which the rod 21 of the application brush part 3 is inserted. Particularly, a lower flange extending from the side surface 81 in a direction perpendicular thereto is formed with a protruding, coupling piece 85 that is to be fixedly inserted into the ring 22 of the rod 21 . Here, since the upper flange of the fixing stand 80 comes into contact with the lower end of the brush rod 2 , it has a diameter identical with that of the brush rod 2 . Further, since the coupling piece 85 of the fixing stand 80 should be inserted into the ring 22 formed at the rod 21 , it has a proper diameter corresponding to the inner diameter of the ring 22 .
[0079] Moreover, since the side surface 81 of the fixing stand 80 on which the comb 8 is formed should be placed in the cutaway portion 31 of the application brush part 3 , it has a cross section conforming to the cross section of the cutaway portion 31 in view of their shapes.
[0080] Therefore, in order to fix the arrangement brush part constructed as above to the application brush part as shown in FIGS. 12 a and 12 b, the fitting hole 82 of the fixing stand 80 is first fitted around the rod 21 with the application portion 7 and the side surface 81 of the fixing stand 80 is adjusted in its position to be in contact with the cutaway portion 31 of the application brush part 3 . When the rod 21 is lowered up to the lower flange of the fixing stand 80 , the coupling piece 85 of the fixing stand 80 is inserted into the ring 22 of the rod 21 . Thus, the application brush part 3 and the arrangement brush part 4 are coupled to each other. At this time, in order to ensure more secure coupling of the coupling piece 85 to the ring 22 of the rod 21 , a tip of the coupling piece 85 inserted into the ring 22 is bent or subjected to thermal bonding. As a result, the coupled state of the ring 22 and the coupling piece 85 can be firmly maintained.
[0081] FIGS. 13 a and 14 a show an application brush part and an arrangement brush part according to a fourth embodiment of the present invention, respectively. Although the brush parts of this embodiment are substantially identical with the application and arrangement brush parts 3 and 4 shown in FIGS. 7 a and 8 a in view of their configurations, the configurations of lower ends thereof are different from each other.
[0082] FIG. 13 a is a front view of the application brush part, and FIG. 13 b is a sectional view taken along line A′-A′ of FIG. 13 a.
[0083] The application brush part 3 of the fourth embodiment is constructed by interposing a plurality of bristles between two parts of a wire folded at the center thereof and spirally twisting the two wire parts a certain number of times. Thus, the application portion 7 thus formed is fixed to the rod 21 formed through the twisting of the wire parts. The application brush part 3 is provided with the cutaway portions 32 formed by longitudinally cutting away some sections of the application portion 7 symmetrically with each other. That is, in view of the four directions in the cross section of the application brush part 3 , the application brush part 3 is provided with the cutaway portions 32 in the north and south directions and with the existing sections of the application portion 7 in the east and west directions.
[0084] A section of the application portion 7 fixed to the lowest end of the rod 21 through the initial twisting of the wire parts is removed so that the ring 22 can be exposed at the lowest end of the rod 21 . With the ring 22 , the application brush part 4 to be described later is coupled to the application brush part 3 .
[0085] FIG. 14 a is a front view of the application brush part, and FIG. 14 b is a sectional view taken along line B′-B′ of FIG. 14 a.
[0086] The arrangement brush part 4 comprises a cylindrical fixing stand 90 , and combs 8 formed on a side surface 91 of the fixing stand 90 .
[0087] The fixing stand 90 takes the shape of a cylinder with a length identical with or slightly shorter than that of the application brush part 3 , and is formed with a central insertion bore 92 longitudinally therethrough so that the rod 21 of the application brush part 3 can be inserted into the insertion bore 92 to cause the fixing stand to be coupled to the application brush part 3 . The side surface 91 of the fixing stand 90 is formed with open windows 94 perforated up to a lower end of the side surface such that when the fixing stand is coupled to the application brush part 3 with the cutaway portions 32 symmetrically formed therein, the existing sections of the application portion 7 of the application brush part 3 protrude outwardly through the windows. A protruding, coupling piece 95 that is to be fixedly inserted into the ring 22 of the rod 21 is formed at the lower end of the side surface 91 .
[0088] More specifically, the side surface 90 of the fixing stand 90 is divided into both lateral symmetric regions due to the formation of the open windows 94 . Lower ends of the both lateral regions of the side surface 91 are connected to each other via a support 96 . The coupling piece 95 is formed to protrude transversely and perpendicularly from the support 96 .
[0089] That is, in view of the four directions in the cross section of the fixing stand 90 , the open windows 94 of the fixing stand 90 are formed symmetrically in the east and west directions, and the combs 8 are formed symmetrically in the north and south directions on the side regions of the side surface 91 of the fixing stand 90 . The coupling piece 95 is formed to protrude from a side of the support 96 , which connects the side regions of the side surface 91 to each other, at a right angle with respect to the combs 8 formed on the side regions of the side surface.
[0090] Therefore, in order to couple the arrangement brush part to the application brush part as shown in FIG. 15 a, the insertion bore 92 of the fixing stand 90 is fitted around the rod 21 , and at the same time, the cutaway portions 32 of the application brush part 3 are placed at closed regions of the side surface 91 of the fixing stand 90 while the existing sections of the application portion 7 of the application brush part 3 are placed in the open windows 94 of the fixing stand 90 . Then, the coupling piece 95 of the fixing stand 90 is fixedly inserted into the ring 22 of the rod 21 that has been lowered up to the lower end of the fixing stand 90 through the insertion bore 92 . As shown in FIG. 15 b, the existing sections of the application portion 7 of the application brush part 3 are placed symmetrically in the east and west directions of the brush rod 2 , and the combs 8 of the arrangement brush part 4 are placed symmetrically in the north and south directions of the brush rod 2 .
[0091] FIG. 16 a shows a fifth embodiment of the present invention, in which an application portion 7 of an application brush part 3 is injection molded from a synthetic resin.
[0092] More specifically, a lower end of a brush rod 2 has a rod 21 extending therefrom, which has a diameter and length identical with that of the metal wire rod 21 of the previous embodiments. The application portion 7 for applying the mascara liquid to the eyelashes is radially formed on an outer circumferential surface of the rod 21 . The rod 21 is made of the same synthetic resin as the brush rod 2 , e.g., polyamide. The application portion 7 formed on the outer circumferential surface of the rod 21 is also made of the same material as the rod 21 by means of injection molding using a precision mold.
[0093] Further, a side surface of the rod 21 is formed longitudinally (perpendicularly to the cross section of the application brush part) with the cutaway portion 31 by cutting away a section of the application portion 7 , as shown in FIG. 16 b. At this time, the cutaway portion 32 is formed by longitudinally cutting away a section of the application portion 7 within an angular range of about 30 to 120 degrees about the center of the cross section of the application brush part 3 .
[0094] Accordingly, the fixing stand 40 of the arrangement brush part 4 used in the first embodiment can be coupled to the application brush part 3 with the application portion 7 formed on the outer circumferential surface of the rod 21 to form a mascara brush 1 , thereby applying the mascara liquid to the eyelashes.
[0095] Alternatively, as shown in FIG. 16 c, the cutaway portions 32 are formed symmetrically such that both sections of the application portion 7 formed at the both lateral sides of the rod 21 with respect to the cross section of the application brush part 3 are symmetric with each other. Thus, the fixing stand 50 of the arrangement brush part 4 used in the second embodiment can be coupled to the application brush part to form a mascara brush 1 .
[0096] Alternatively, the fixing stand 80 of the arrangement brush part 4 used in the third embodiment can be coupled to an application brush part 3 in which the cutaway portion 31 is formed at a side of the outer circumferential surface of the rod 21 by cutting away a section of the application portion 7 and the ring 22 is formed by perforating the lower end of the rod 21 , as shown in FIGS. 17 a and 17 b, thereby forming a mascara brush 1 .
[0097] Alternatively, the fixing stand 90 of the arrangement brush part 4 used in the fourth embodiment can be coupled to an application brush part 3 in which cutaway portions 32 are formed at both sides of the rod 21 by cutting away sections of the application portion 7 and the ring 22 is formed by perforating the lower end of the rod 21 , as shown in FIG. 17 c, thereby forming a mascara brush 1 .
[0098] In the mascara brush of the present invention, the application brush part for receiving a large amount of mascara liquid is formed at a side of the brush rod, and the arrangement brush part with the comb is formed at the other side of the brush rod. Thus, the mascara brush can performs two functions of application and arrangement by the single brush rod. Accordingly, it is possible to provide a mascara brush capable of ensuring more convenient make-up by allowing application of the mascara liquid (volume-up effect) and arrangement of eyelashes (curling, long lash and clean effects) at one time upon application of mascara to the eyelashes.
[0099] Further, in the case where one or more columns of combs are formed in the arrangement brush part, when the mascara liquid is applied by the application brush part and the eyelashes are then arranged by the arrangement brush part, the effects of volume-up, curling, long lash and clean can be obtained. Meanwhile, even when the mascara liquid is applied to the eyelashes by using only the arrangement brush part with the plurality of columns of combs, it is possible simultaneously to obtain a weak volume-up effect, and the effects of curling, long lash and clean.
|
The present invention relates to a mascara brush. The present invention provides a mascara brush, wherein a single brush rod of the mascara brush is formed with both an application brush part with an application portion for applying a mascara liquid to eyelashes and an arrangement brush part with a comb for arranging the eyelashes in order to simultaneously perform the application of the mascara liquid and arrangement of the eyelashes, thereby conveniently imparting the effects of clean, long lash and curling to the eyelashes through a single process, the structure of the mascara brush is simplified so that a manufacturing process can be relatively simplified, and stability in use can be obtained due to the securely coupled state.
| 0
|
BACKGROUND
[0001] When metals are attached to each other, a form of wear called galling can occur between the surfaces where they are connected or adhered. When metals gall, the material is pulled with the contacting surface over time. This is caused by a combination of friction and adhesion between the surfaces, followed by a tearing of crystal structure. This can leave some materials friction welded to adjacent surfaces. Metals in particular gall due to their atomic structures. Galling can occur on metal surfaces where there is a lack of lubrication between the surfaces.
[0002] In many industries, including aerospace, medical devices, oil and gas, and fasteners, galling is prevented by the used of anti-gallant coatings. Anti-gallant coatings are chemical coatings applied to the surface of metals which are connected and prevent later galling. Anti-gallant coatings can have a variety of chemical compositions and are used to protect specific metal parts from galling. The anti-gallant coating chemically reacts with adjacent metal parts when stress is applied to the adhesion.
[0003] The application of anti-gallant coatings has previously been accomplished by mechanical means such as brushes, sponges and rollers, in addition to air sprays. These methods are cumbersome both because they are imprecise and may result in poor quality coatings which adhere to other parts of the item, not just the metal parts of interest. Mechanical methods that require a human hand to apply the coating, such as brushes or sponges, may miss parts, apply the coating unevenly, or get the coating on unwanted areas. Traditional air sprays are also imprecise, as a large amount of the coating ends up in the atmosphere as opposed to on the surface of interest. Additionally, overspray resulting from air sprays or similar methods creates uneven coatings, leaving a signature and feathering on the edges of the coated part.
[0004] Industry methods have long used masking to prevent other parts from being touched or coated during the anti-gallant coating method. Masking is a time-consuming preparation process in which parts of the device are covered or “masked” to prevent the application of anti-gallant coating to that part. This process greatly increases the time and money spent to apply anti-gallant coatings to certain metal parts. If masking is done improperly, there is additional cost of poor quality when the device must be cleaned and the anti-gallant coating re-applied to the correct areas, if the device can be used after improper masking.
[0005] Today, industry standards for applying anti-gallant coatings use mechanical methods which can cause inconsistencies, thick coatings, imprecise applications, feathering on edges, and require masking of nearby metal parts when the substrate is being coated.
SUMMARY
[0006] A method for applying anti-gallant coating to parts, the method comprising: providing a precise manipulation device having an ultrasonic sprayer thereon, the ultrasonic sprayer configured to dispense anti-gallant material; positioning a part to receive anti-gallant material dispensed by the ultrasonic sprayer; and activating the ultrasonic sprayer to apply the anti-gallant material to the part according to a spray path executed by the precise manipulation device, to form an anti-gallant coating on the part.
[0007] A system for applying anti-gallant coating to parts, the system comprising: a container for holding a supply of anti-gallant material; an ultrasonic nozzle connected to the container, the ultrasonic nozzle configured to dispense the anti-gallant material; and a precise manipulation device configured to move the ultrasonic nozzle with respect to a part along a spray to deposit an anti-gallant coating on a defined area or areas of the part.
[0008] A coated part comprising: a substrate, and an ultrasonically applied anti-gallant coating on the substrate, wherein the anti-gallant coating has a uniform thickness and has substantially no feathering at an edge of the anti-gallant coating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of an ultrasonic sprayer attached to a robotic arm spraying a metal sheet with anti-gallant coating.
[0010] FIG. 2 is a flow chart of a method of applying an anti-gallant coating to a part without masking.
DETAILED DESCRIPTION
[0011] Leveraging ultrasonic nozzle technology and high precision machines, such as robotic arms, to apply anti-gallant coatings to substrates allows not only for higher precision in coatings, but also for evenly, consistently applied coatings without feathering that will wear at the same rate, less environmental harm due to minimal coating release into the atmosphere, and the elimination of the need of masking, resulting in lower costs and time.
[0012] Previous methods have not used high precision instruments, such as ultra-sonic nozzles, or robotic arms, to apply anti-gallant coatings. High precision ultra-sonic nozzles, such as those disclosed in U.S. Pat. No. 9,242,049, offer a coating spray which is much more precise than traditional paint spray nozzles. Unlike traditional spray nozzle systems, ultrasonic spray nozzle systems are more environmentally friendly due to their higher precision and resulting lower waster.
[0013] Similarly, anti-gallant coating methods have not leveraged technology such as precision devices or robotic arms. Precision devices such as gantry, six-axis or selective-compliance-articulated robotic arms, cam-operated articulable arms, or computer numerical control machines, are many times more precise than the human hand, and allow for repeatable, consistent coatings.
[0014] FIG. 1 is a schematic diagram of system 10 for applying anti-gallant coating. System 10 includes robotic arm 12 , container 14 , ultrasonic nozzle 16 , substrates 18 , 20 , controller 22 and user interface 24 .
[0015] Robotic arm 12 is an example of a high precision device used to apply precise, even coatings. In FIG. 1 , robotic arm 12 is a gantry robot which had three prismatic joints and whose axes coincide with Cartesian coordinates. Robotic arm 12 can be programmed through user interface 24 , and both movement of the arm and release of spray can be controlled through programming. Robotic arm 12 can be a gantry, a six-axis or a selective-compliance-articulated robot arm (SCARA). A gantry arm, also known as a Cartesian arm, is a mechatronic device which uses motors and linear actuators to position a tool, such as an ultrasonic nozzle. A gantry arm makes movements along X, Y and Z coordinates. A SCARA arm similarly moves along X, Y, and Z axes but may also incorporate a θ axis. Six-axis arms offer more directional control and are similar to the human arm in movement style, but with higher precision. All three types offer accuracy ranges if at least 0.1 mm, while varying versions of gantry arms can be as precise as 10 μm. Alternatively, the precision device could be any type of robotic device useable for spray coating application, such cam-operated articulable arms or a computer numerical control (CNC) machine, which are simpler and may be programmed with a repeatable set of movements.
[0016] Container 14 holds an anti-gallant coating. Anti-gallant coatings are used particularly with stainless steel and other corrosion-resistant metal alloys which are prone to galling. Galling is a severe form of adhesive wear which occurs due to the transfer of material between sliding surfaces. Metallic surfaces are prone to galling particularly when there is poor lubrication. This occurs in a variety of industries and metal parts, including engine bearings, hydraulic cylinders, gas turbine vanes and blades, valves, screw threads, pistons and actuators. Anti-galling coatings can include hard anodized coatings, silver plated coatings, thermal spray coatings, electroless nickel coatings, dry lubrications, and many other industry-specific coatings.
[0017] Ultrasonic nozzle 16 is attached to robotic arm 12 . Ultrasonic nozzles allow for the application of precise, thin film coatings without feathering effects. While traditional mechanical methods such as rollers or brushes create thick or uneven coatings, traditional pressure nozzle spray applications are imprecise and leave up to ninety percent of the coating material dispersing in the air around the substrate instead of sticking to the substrate. Ultrasonic nozzle sprayers, in contrast, produce a fine mist spray which is focused. Ultrasonic nozzles atomize liquids using high frequency sound waves, which are outside of the human hearing range, rather than forcing liquid through a small orifice as in traditional pressure spray nozzles. Ultrasonic nozzles result in a more uniform dispersion of coating particles in very thin layer due to the suspension of the particles in the nozzle throughout spraying. Commercially available ultrasonic nozzles allow for adjustment of the spray pattern within 1.78 mm to 25 mm, depending on the specific nozzle. This reduces over-spraying, which both reduces atmosphere contamination and prevents a feathering effect on the edges of the sprayed part, allowing for an evenly distributed coating without any signature.
[0018] Substrate 18 is an example of a metal part which is to be coated with anti-gallant coating. Many metals, including aluminum and stainless steel, can gall easily, while others, such as steel or brass, are less prone to galling. Substrate 20 is an example of a metal part which is attached to substrate 18 , but should not be coated with anti-gallant coating. In prior art, substrate 20 would be masked to prevent application of the anti-gallant coating to that part. Masking is a method of protecting certain parts of an item from exposure to the coating. With masking, certain parts are painstakingly covered or sealed off to ensure no coating comes into contact with those parts. Incorrect masking can lead to further problems and repeated attempts to apply anti-gallant coatings. However, with the use of a high-precision system for applying the coating, substrate 20 does not need to masked, saving time, money, and potential errors.
[0019] Controller 22 is used to control the movement of the robotic arm and the spray of the ultrasonic nozzle. Controller 22 may be either programmable through user interface 24 , or controlled directly by the user to create a path for robotic arm 12 to follow. Specifically, controller 22 is complex enough to allow coating of substrate 18 but not coating of substrate 20 . User interface 24 allows programming and control of robotic arm 12 . Once programmed, controller 22 includes memory that stores instructions and data (programming) that allows robotic arm 12 to be moved precisely along a defined path to replicate application of the anti-gallant coating on multiple parts.
[0020] System 10 can be used to apply anti-gallant coatings of varying thickness to small, specific areas of substrates without masking.
[0021] FIG. 2 is a flow chart of method 28 for applying an anti-gallant coating to a metal part without masking. Method 28 includes loading instructions (step 30 ), loading container (step 32 ), securing sprayer (step 34 ), mounting metal parts (step 36 ), spraying metal parts on area of interest (step 38 ), and removing metal parts (step 40 ).
[0022] Method 28 begins with step 30 , when the user programs a precise manipulation device. As discussed earlier, the precise manipulation device may be a robotic arm, such as arm 12 pictured in FIG. 1 , any other type of camera operated articulable arm, or a CNC device. Depending on the requirements for the particular type of device, the programming step may include programming a simple, repeatable set of movement and spraying, or it may be complex.
[0023] Next, in step 32 , the user loads the anti-gallant coating into the ultrasonic sprayer, such as sprayer 16 pictured in FIG. 1 . Here, the user can select one of many types of anti-gallant coatings, depending on the substrate being coated. This can include hard anodized coatings, silver plated coatings, thermal spray coatings, electroless nickel coatings, dry lubrications, and many other industry-specific coatings, which work differently with varying substrates.
[0024] In step 34 , the user secures the ultrasonic sprayer to the precise manipulation device. The ultrasonic sprayer must be secure such that the movement of the precise manipulation device will not shake the ultrasonic sprayer, altering the spray pattern. The ultrasonic sprayer can be secured through fasteners, clasps, or any other reasonable method for attachment to the manipulation device.
[0025] Next, in step 36 the items to be coated are placed in range of the precise manipulation device. In FIG. 1 , the example given is substrate 18 . Once the substrate is secured, there is no need to mask unwanted parts. Instead, the precise manipulation device can be programmed specifically, with more precision than a human hand, to spray only parts that should be coated with the anti-gallant coating. Even without masking, the high precision of the ultrasonic sprayer and precise manipulation device prevent feathering on the edges of the substrate.
[0026] In step 38 , the program for the precise manipulation device should be run, carefully controlling both spray and movement. This process can be completed in a “quiet” environment, as the ultrasonic sprayer does not produce waste associated with traditional pressure sprayers and there is no need to keep a fan or vacuum to eliminate that waste. The coating that is applied to the part will be thin, even, and will not contain a signature such as feathering. Finally, once coating is completed, the substrates or other coated items should be removed from their stationary position (step 40 ).
[0027] The present invention can produce a coating that is uniform in thickness, which is defined as thickness with less than twenty percent variation. Additionally, there is substantially no feathering along the edges of the coating, or any other signature left by the coating method, that can occur when other methods are utilized.
[0028] Method 28 presents unique benefits in the anti-gallant coating process that have not previously been addressed. First, the method presented does not require masking. Currently, masking in anti-gallant coating processes is more time, energy and money consuming than applying the anti-gallant coating itself. The use of the ultrasonic spray system eliminates the need for masking because of its high accuracy and precision. Additionally, the use of a robotic arm or other manipulation device allows for higher precision and repeatability than using a human hand to apply the coating. Moreover, the coating that is applied to the substrate is uniform in thickness, and can be applied very thinly to materials on which a thick coating is not desired. Finally, the use of a quiet environment in which there is no aerosol waste is an environmental improvement.
DISCUSSION OF POSSIBLE EMBODIMENTS
[0029] The following are non-exclusive descriptions of possible embodiments of the present invention.
[0030] A method for applying anti-gallant coating to parts, the method comprising: providing a precise manipulation device having an ultrasonic sprayer thereon, the ultrasonic sprayer configured to dispense anti-gallant material; positioning a part to receive anti-gallant material dispensed by the ultrasonic sprayer; and activating the ultrasonic sprayer to apply the anti-gallant material to the part according to a spray path executed by the precise manipulation device, to form an anti-gallant coating on the part.
[0031] The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
[0032] Providing a precise manipulation device includes securing the ultrasonic sprayer to the precise manipulation device.
[0033] The method includes loading instructions in a controller, wherein the instructions specify movement of the precise manipulation device and spraying of the ultrasonic sprayer, and wherein the instructions define the spray path, and executing the instructions in the controller to control movement of the precise manipulation device and operation of the ultrasonic sprayer to spray anti-gallant material onto a defined area or areas of the part.
[0034] The controller controls the precise manipulation device and the ultrasonic sprayer to produce a coating with a non-feathered edge.
[0035] The method includes spraying the anti-gallant material onto the part in a low-wind environment.
[0036] The precise manipulation device is configured to achieve positional accuracy within a range of 10 μm to 0.1 mm.
[0037] The precise manipulation device comprises at least one of a robotic arm or a computer numerical control.
[0038] The anti-gallant coating comprises a hard anodized coating, a silver plated coating, a thermal spray coating, an electroless nickel coating, or a dry lubrication.
[0039] The ultrasonic sprayer is configured to adjust spray of the anti-gallant material within a spray width of 1.78 mm to 25 mm.
[0040] A system for applying anti-gallant coating to parts, the system comprising: a container for holding a supply of anti-gallant material; an ultrasonic nozzle connected to the container, the ultrasonic nozzle configured to dispense the anti-gallant material; and a precise manipulation device configured to move the ultrasonic nozzle with respect to a part along a spray to deposit an anti-gallant coating on a defined area or areas of the part.
[0041] The system of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
[0042] The system includes a controller containing a memory configured to store and deliver instructions, wherein the instructions specify movement of the precise manipulation device and spraying of anti-gallant material by the ultrasonic nozzle.
[0043] The controller controls the precise manipulation device and the ultrasonic nozzle to produce the anti-gallant coating with a non-feathered edge.
[0044] The ultrasonic nozzle is configured to spray anti-gallant material onto the part in a low-wind environment.
[0045] The precise manipulation device comprises at least one of a robotic arm or a computer numerical control.
[0046] The precise manipulation device is configured to achieve positional accuracy within a range of 10 μm to 0.1 mm.
[0047] The anti-gallant coating comprises a hard anodized coating, a silver plated coating, a thermal spray coating, an electroless nickel coating, or a dry lubrication.
[0048] The ultrasonic nozzle is configured to adjust spray of the anti-gallant material within a spray width of 1.78 mm to 25 mm.
[0049] A coated part comprising: a substrate, and an ultrasonically applied anti-gallant coating on the substrate, wherein the anti-gallant coating has a uniform thickness and has substantially no feathering at an edge of the anti-gallant coating.
[0050] The part of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
[0051] The anti-gallant coating comprises a hard anodized coating, a silver plated coating, a thermal spray coating, an electroless nickel coating, or a dry lubrication.
[0052] While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
|
A method for applying anti-gallant coating to metal parts utilizes an ultrasonic sprayer driven by a precise manipulation device such as a robotic arm for high efficiency and precision. The method does not require masking adjacent or nearby metal parts, decreases time and money spent applying the anti-gallant coating, and is environmentally friendly.
| 1
|
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to the field of manufacturing textiles using chains as a component. The use of chains as a component of a textile has typically been an industrial process of assembling chain links in both an X and Y orientation in order with separate rings interlocking the individual links in both the X and Y directions. The resulting textile is commonly known as “chain mail.” Historical uses of chain mail textile include armor, jewelry, bags, and pot scrubbers. But manufacturing of chain mail requires each link in the chains to accommodate two dimensions of connection. This requires a manufacturing process to start with creating the links in the chain mail. However, chains are typically manufactured with the links in a single, linear direction. The chain mail manufacturing techniques that are known in the art require individually linking each link with separate rings that can be opened and closed with commercially available metalworking tools such as pliers. In addition, many chains may have esthetic appearances that would be beneficial if incorporated into a textile, but in the form of an existing linear chain, cannot be used to create traditional chain mail. Therefore, there is a need for manufacturing a textile out of chains that uses pre-made chains and does not require individual link rings.
BRIEF SUMMARY OF THE INVENTION
[0002] The present invention provides a new, novel method and process of manufacturing chains to create a textile. The process involves use of a substrate on which chains can be set with a mounting frame and then interconnected. Once the chains are interconnected, the substrate may be removed from the textile through a method of separation such as dissolving the substrate in the case of a dissolvable substrate or melting the substrate in the case of a wax substrate.
DESCRIPTION OF THE FIGURES
[0003] FIG. 1 . Top view of finished chain textile.
[0004] FIG. 2 . Top view of substrate held in a mounting frame.
[0005] FIG. 3 . Top view of finished textile mounted on substrate.
[0006] FIG. 4 . Side view of the mounting frame with substrate.
[0007] FIG. 5 . Side view of the mounting frame with chain laid onto substrate.
[0008] FIG. 6 . Side view of the mounting frame with the stitching.
[0009] FIG. 7 . Side view of the mounting frame with the stitching tightened.
[0010] FIG. 8 . Side view of the mounting frame after the substrate has been dissolved in a solvent.
[0011] FIG. 9 . A close-up photograph of the finished textile.
[0012] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention. In the drawings, the same reference numbers and any acronyms identify elements or acts with the same or similar structure or functionality for ease of understanding and convenience. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the Figure number in which that element is first introduced (e.g., element 204 is first introduced and discussed with respect to FIG. 2 ).
DETAILED DESCRIPTION OF THE INVENTION
[0013] Various examples of the invention will now be described. The following description provides specific details for a thorough understanding and enabling description of these examples. One skilled in the relevant art will understand, however, that the invention may be practiced without many of these details. Likewise, one skilled in the relevant art will also understand that the invention can include many other features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below, so as to avoid unnecessarily obscuring the relevant description. The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the invention. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.
[0014] The chain component is typically a sequence of links, where a given loop of one link has a front and rear neighboring link that loops through the link. The chain component may be comprised of any durable solid material, including but not limited to metal, plastic, glass, rubber, ceramic, or fiber. However, in the textile, the two neighboring chains do not have chain links that connect them on the axis that is normal to the length of the chain. In one embodiment one or more threads pass through the links of neighboring chains so that they are stitched together tightly. As shown in FIG. 1 , the chains ( 100 ) are bound to each other by means of the threads ( 101 ) that run perpendicular to the longitudinal axis of the chains ( 100 ). As shown in FIG. 9 , the chains may be laid side by side and the threads intertwined with the links in order to form a flexible textile made up of the series of chains. In the preferred embodiment, the chains are selected where the chain links comprising the chains are shaped to lay flat against a planar surface, that is, the loop of the link is shaped to accommodate the intertwined links of its neighboring links along the chains' length. In the preferred embodiment, the thread is comprised of nylon, acetate or other strong materials that are resistant to water or other solvents. For example, these threads may also include cotton, wool, other natural fibers, polyester, rayon, silk, metal, rubber, latex, polypropylene, Kevlar®, Teflon®, or Nomex®, alone or in combination with other materials. In the preferred embodiment, the thread is resistant to the solvent that dissolves the substrate or the head used to melt the wax substrate.
[0015] The flexibility of a chain makes it difficult to sew one chain to its neighboring chain reliably and in a manner where the regularity of the link pattern is consistent both along the longitudinal axis of the chains as well as along the axis perpendicular to the chains' longitudinal axis. One object of the invention is to insure the regularity of the chain links comprising the textile in order that it is esthetically pleasing and functional.
[0016] In another preferred embodiment, the chain textile is fabricated using a multi-step process. The first step of the process is the selection of a substrate upon which manufacture of the textile takes place. The suitable substrate must be strong enough to withstand stretching in both dimensions along its planar surface without tearing. In addition, it must be sufficiently strong that while in the condition of being stretched, the process of sewing needles penetrating the substrate will not cause the substrate to fail. Finally, the substrate has to be soluble in a solvent or with a relatively low melting point. In the preferred embodiment, the substrate is a resinated paper that is water soluble. Other substrates may be used to accommodate different density of chains.
[0017] In the first step of the process, the substrate ( 200 ) is stretched within a frame, FIG. 2 . In one embodiment, a first set of threads ( 201 ) are run from the frame to the edges of the substrate and tension applied in order to establish a strong, substantially planar surface for the substrate. FIG. 4 shows a side view of the frame with the substrate. In the second step of the process, the chains ( 300 ) are laid out on the substrate side by side. See FIG. 3 . FIG. 5 shows a side view of the chains lying on the substrate. In one embodiment, the substrate is marked with registration marks in order to correctly position the chains. In another embodiment, pins are inserted at the end of the chains that pass through the substrate in order that the ends of the chains are fixed. In the third step of the process, a second set of threads ( 301 ) are passed through the links of the neighboring chain in order to bind the neighboring chains to the substrate and to each other. FIG. 6 shows a side view of the threading of the chain against the substrate. The thread ( 301 ) passes through the hole formed by the chain link, down through the substrate, and then back through the substrate into the next hole formed by the neighboring chain link. In one embodiment, the threads run along the axis perpendicular to the longitudinal axis of the chains. In this embodiment, each new loop of the thread is passing through the next neighboring chain link. In another embodiment, the threads run along a direction at a diagonal to the longitudinal axis of the chains. In either embodiment, threading that runs in both a perpendicular and diagonal direction may be used together. The specific pattern of threading may be varied, so long as the threading establishes that each chain is sufficiently bound to its two neighboring chains, except for the chains at the edge of the textile piece, which are bound to the single neighboring chain. FIG. 7 shows a side view down the longitudinal axis of the chains showing the chains being bound together on the substrate.
[0018] In the final step of the manufacturing process, the frame with the substrate and chain textile attached to it is placed into a bath containing a solvent that can dissolve the substrate without damaging either the chains, the chains' finish or the threads. In the preferred embodiment, the solvent is water. After the solvent has dissolved the substrate, all that remains is the manufactured textile piece. FIG. 8 . The textile piece may then be cleaned and prepared to be integrated into any kind of garment, jewelry, accessory, luggage or other item that textiles are useful for.
[0019] In another embodiment, in the last step of the manufacturing process, the solvent is applied to the substrate and chain textile. Such application can be by various methods, such as pouring, spraying or sponging the solvent onto the substrate. After the solvent has dissolved the substrate, all that remains is the manufactured textile piece. FIG. 8 . The textile piece may then be cleaned and prepared to be integrated into any kind of garment, jewelry, accessory, luggage or other item that textiles are useful for.
[0020] In another embodiment, the substrate may be a solid substance that can be dissolved or melted. In this embodiment of the invention, the chains may be pressed into the surface of the solid substrate, or the substrate may have channels pressed or otherwise formed in the surface of the substrate. The chains may then be laid into the channels. In one embodiment, the substrate is a wax. This approach permits the chains to be laid in circular or spiral patterns, or patterns involving a corner. Once the chains are laid into the substrate, the threading process is performed to sew the chains together into a textile. At that point, the substrate is removed by means of dissolving the substrate into the solvent or melting the substrate, as in the case of wax. The substrate has to be thin enough so that the thickness of the substrate does not impede the threading process by resisting the movement of the needle, nor introduce slack into the thread stitches when the substrate is removed. In one embodiment, this is accomplished by coating the dissolvable substrate with the solid substrate. In one embodiment, a wax layer is coated on dissolvable paper. In this embodiment, the wax can be patterned with the channels into which the chains are placed. When the textile has been assembled, the paper substrate is dissolved using water. If the water is heated to sufficient temperature above the melting point of wax, any wax residue on the chains can be removed.
[0021] It is appreciated that various features of the invention which are, for clarity, described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable combination. It is appreciated that the particular embodiment described in the specification is intended only to provide an extremely detailed disclosure of the present invention and is not intended to be limiting.
|
This invention discloses a novel system and method for creating textiles out of chains connected by thread. The process involves use of a dissolvable or removable substrate on which chains can be set and then interconnected, and the subsequently removed.
| 3
|
CROSS REFERENCE TO RELATED APPLICATIONS
This Application claims priority to U.S. Provisional Application No. 60/878,712 filed Jan. 4, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a motorized track system, and more particularly toward a transmission for a motorized track system of the type used in position adjustors for vehicular seats, windows and the like.
2. Related Art
Vehicle seat assemblies are often provided with a motorized track system that enable the position of the seat assembly within a motor vehicle to be adjusted in the forward and rearward directions. Similarly, vehicular window assemblies may include a motorized track system of similar construction to enable the position of the window to be adjusted in up and down directions. In each case, the supported element is guided by the motorized track system for back and forth movement to change its position, as desired.
In the case of vehicular seat assemblies, for example, such adjustment capability is desired to enable vehicle operators of various body dimensions to be seated comfortably within the motor vehicle. In these systems, an electric motor may be coupled to a lead screw positioned within a sliding track assembly. In such an arrangement, the lead screw may be fixed or may rotate but a drive nut interacts with the lead screw through motor-driven rotation to move the vehicle seat assembly forward or rearward. A motorized window regulator assembly may work in much the same manner.
A transmission is generally provided in these types of motorized track systems for transferring power from the motor to the drive nut. In configurations where a pair of sliding tracks are employed, the electric motor may be mounted on a transverse beam bridging each of the tracks, for example in the center of the tracks or at one end of the tracks. Because certain components within the transmission rotate while others are held generally stationary, vibrations may be produced within the transmission when the transmission is operational, thereby causing noise. Another cause of noise is lateral movement of the components within the transmission housing.
Various proposals have been advanced for addressing the noise issues in a transmission for a motorized track system. For example, U.S. Pat. No. 7,051,986 to Taubmann et. al., granted May 30, 2006, discloses a system wherein a shim disk, identified as item number 96 ′, is used to compensate for axial play. Shim disks are subject to manufacturing variances, however and may not consistently address the noise issues. Accordingly, there is a need for a motorized track system for use in vehicular applications that meets or exceeds the established strength, speed and noise requirements. There is also a need to provide a reliable transmission that includes shock absorbing components to reduce the vibration between those components in the transmission, and to reduce noise and to eliminate lateral movement of certain components. There is a further need to provide a reliable, acceptable motorized track system for providing translational adjustment, which avoids one or more of the above-noted problems.
SUMMARY OF THE INVENTION
The invention overcomes the disadvantages and shortcomings of the prior art by providing a transmission assembly for a motorized track system of the type used to adjust the position of a support element such as a vehicular seat, window or the like. The assembly comprises an externally threaded lead screw establishing a longitudinal direction along which a supported element is moved back and forth to change its longitudinal position. A drive nut is operatively engaged with the lead screw. Motor-driven rotation of the drive nut causes the supported element to be longitudinally displaceable along the lead screw. A housing generally surrounds the drive nut. The housing includes a mounting bracket for attaching to the supported element so as to translate the supported element together with the drive nut longitudinally along the lead screw. A compressible washer is disposed between the drive nut and the housing. The compressible washer exerts a bias between the drive nut and the housing so as to eliminate lateral movement of the drive nut within the housing and to dampen or otherwise eliminate noise producing vibrations from the transmission.
According to another aspect of the subject invention, a motorized track system is provided of the type used to adjust the position of a supported element such as vehicular seat, window or the like. The track system comprises a base track, and an externally threaded lead screw. The lead screw establishes a longitudinal direction along which a supported element is moved back and forth to change its longitudinal position. A driven track is interactive with the base track for longitudinal sliding movement there between. A drive nut is operatively engaged with the lead screw. A housing is fixedly connected to the driven track and generally surrounds the drive nut. The housing includes a mounting bracket for attaching to the supported element to translate the supported element together with the drive nut and the driven track longitudinally along the lead screw. A compressible washer is disposed between the drive nut and the housing.
According to a further embodiment of the invention, a method is provided for eliminating play between a drive nut mounted in a transmission for use in a motorized track system having a lead screw, the transmission including a housing and a worm gear. The method comprises the steps of locating first and second bushings on opposite sides of the drive nut, placing a wave washer between at least one of the first and second bushings and the drive nut, and capturing the drive nut, worm gear, first and second bushings, and wave washer in a housing so that the wave washer is partially compressed. The wave washer provides an axial biasing force that reduces the tendency for the drive nut to vibrate longitudinally relative to the first and second bushings which might otherwise produce noise.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein:
FIG. 1 is a simplified perspective view of an exemplary automobile;
FIG. 2 is a perspective view of vehicular seat including a motorized track system according to the subject invention;
FIG. 3 is a prospective view of a motorized track system according to one embodiment of the subject invention;
FIG. 4 is an end elevation view of the motorized track system of FIG. 3 ;
FIG. 5 is an exploded view of a portion of the motorized track system depicting the base and driven tracks, together with the lead screw and transmission assembly according to the subject invention;
FIG. 6 is an enlarged view of the transmission assembly as circumscribed by broken lines in FIG. 5 ;
FIG. 7 is an exploded view of an alternative embodiment of the transmission assembly;
FIG. 8 is a partially sectioned view as taken longitudinally through the transmission assembly; and
FIG. 9 is a view as in FIG. 8 but showing the compression washers deflected in response to reaction forces between drive nut and housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, an exemplary motor vehicle is generally shown at 10 in FIG. 1 . The vehicle 10 in FIG. 1 is merely exemplary, and may instead take the form of a light duty truck, SUV, minivan, bus, train, airplane, boat, or any other such vehicle or stationary application in which a motorized track assembly may be employed. In this specific example, however, the vehicle 10 is depicted including a passenger seat 12 having the customary back rest 14 and seat cushion 16 , as illustrated in FIG. 2 . The seat 12 is supported above a motorized track system, generally indicated at 18 , that is configured to allow an occupant to adjust the position of the seat 12 in longitudinally forward and rearward directions relative to the vehicle 10 . Although the following description of the subject invention is carried out by reference to vehicular seating application, it will be understood by those of skill in the art that the subject track system 18 is adaptable for other uses, including window regulator systems, and other applications which include a supporting element which is moved back and forth under the influence of a motor to change its longitudinal position.
Referring to FIGS. 2-5 , the track system 18 is shown in greater detail including two track sets that are generally parallel to one another. Each track set includes a base rail 20 that is coupled to a structure such as the floor of the vehicular passenger compartment. An upper, driven rail 22 is coupled to the seat 12 and is slidably interconnected to the base rail 20 so that the two can slide relative to one and other in a fore and aft direction, in the case of the vehicular seating application. In the case of a window regulator application, the driven rail 22 would be oriented so as to slide up and down relative to the base rail 20 . Those of skill in the art will envision other applications and orientations for the track system 18 . A bridge-like transverse rail 24 interconnects the driven rails 22 from each track set so that they are coupled together and move in unison when the seat 12 is adjusted forward or rearward.
A transmission assembly, generally indicated at 26 , is operatively disposed between the base 20 and driven 22 rails so as to forcibly displace one rail relative to the other during position adjustment of the supported element—be that a vehicular seat 12 , a window, or other component.
The transmission assembly 26 interacts with an externally threaded lead screw 28 to produce the desired longitudinal displacement. The particular method by which the transmission assembly 26 interacts with the lead screw 28 can be varied among different mechanically equivalent arrangements, two of which are depicted in the figures. More specifically, as shown in FIGS. 5 and 6 , the transmission assembly 26 is longitudinally fixed relative to the lead screw 28 and translates, as a unit, therewith. However, in an alternative embodiment of the invention which will be described subsequently in connection with FIGS. 7-9 , the transmission assembly 26 ′ interacts with the lead screw 28 ′ by traveling the length of the lead screw 28 ′. I.e., in this latter example, the transmission assembly 26 ′ translates longitudinally relative to a stationary lead screw 28 ′.
Referring specifically now the embodiment depicted in FIGS. 5 and 6 , the lead screw 28 is rotatably supported at one end by a bearing block 30 which in turn is affixed to the driven rail 22 by a fastener 32 . The other end of the lead screw 28 is coupled to the transmission assembly 26 , which in turn is attached to the opposite end of the driven rail 22 . The transmission assembly 26 receives a rotary input from an electric motor 34 as shown in FIGS. 2-4 . The motor 34 is provided with flexible drive shafts 36 extending from opposite ends. Each drive shaft 36 couples to a worm gear 38 which is a component of the transmission assembly 26 . Thus, as each drive shaft 36 is turned by the armature of the motor 34 , the worm gear 38 is caused to spin. The transmission assembly 26 includes a housing, generally indicated at 40 , that rotatably supports the worm gear 38 via a pair of left and right cover halves 42 , 44 as depicted in FIG. 6 . The cover halves 42 , 44 may be made from a lubris polymeric material of the type known to possess inherent dry bearing qualities. Alternatively, bushings 46 may be interposed between the worm gear 38 and cover halves 42 , 44 to provide a bearing function. Fasteners (not shown), heat staking, self-locking clips, or other methods may be used to securely join the cover halves 42 , 44 together as an integral unit.
The left 42 and right 44 cover halves are surrounded at their longitudinally spaced ends by a pair of isolators 48 which serve primarily to dampen vibrations between the left 42 and right 44 cover halves and a rigid, preferably metallic, outer bracket 50 . The isolators 48 may be manufactured from a rubber or highly resilient material. The bracket 50 has, in this embodiment, a generally U-shaped configuration with outwardly bent flanges containing mounting holes 52 . According to the embodiment of this invention illustrated in FIGS. 5 and 6 , the transmission assembly 26 is affixed to the driven rail 22 via fasteners (not shown) passing through the mounting holes 52 in the bracket 50 .
The transmission assembly 26 further includes a drive nut 54 having external gear teeth in meshing contact with the threads of the worm gear 38 . The drive nut 54 has a rotational axis which is generally transverse to the rotational axis of the worm gear 38 . Like the worm gear 38 , the drive nut 54 is also rotationally captured between the left 42 and right 44 cover halves of the housing 40 . In this embodiment of the invention, the lead screw 28 is fixedly joined to the drive nut 54 such that they rotate in unison about a common axis. As a result, when the drive nut 54 is forcibly rotated through the interaction of the worm gear 38 , the lead screw 28 turns within its bearing block 30 .
Located along the length of the lead screw 28 , between the transmission assembly 26 and the bearing block 30 , a fixed nut 56 is threadably disposed on the lead screw 28 . The fixed nut 56 is affixed relative to the base rail 20 by a mounting bracket 58 secured through fasteners 60 . In this manner, the fixed nut 56 is stationary relative to the base rail 20 . As the lead screw 28 is turned through operation of the transmission assembly 26 , its screw threads interact with internal threads in the fixed nut 56 , propelling the attached driven rail 22 , transmission 26 and transverse rail 24 in a longitudinal direction relative to the length of the lead screw 28 . By this means, the supported element, be it a seat 12 , window or other, is advanced or retracted in a longitudinal direction, as powered by the motor 34 .
Turning now to FIGS. 7-9 , an alternative yet mechanically equivalent construction of this transmission assembly 26 ′ is depicted, wherein prime designations are used for convenience to distinguish between the two embodiments of this invention. In this example, the lead screw 28 ′ is fixedly attached to the base rail (not shown) so that it does not rotate. In furthering this example, the drive nut 54 ′ is provided with internal screw threads 62 ′ that threadably interact with the outer turns of the lead screw 28 ′. The bracket 50 ′ is provided with through holes 64 ′ that allow the lead screw 28 ′ to pass completely through the transmission assembly 26 ′.
When the drive nut 54 ′ is turned by the worm gear 38 ′, its internal threads 62 ′ advance along the lead screw 28 ′, in either longitudinal direction depending upon which way the drive nut 54 ′ is rotated, and thereby propel the entire transmission assembly 26 ′ in either longitudinal direction.
A particular issue arising from prior art designs of transmission assemblies used for such motorized track systems results from premature component wear particularly in the area of the drive nut 54 , 54 ′ between the cover halves 42 , 44 , 42 ′, 44 ′. Similarly, noise of an objectionable level is created whenever the transmission assembly 26 , 26 ′ is activated from a rest condition. This is caused by the interaction between the threads of the worm gear 38 and the external teeth on the drive nut 54 , which causes a reaction force in the drive nut 54 to move in either longitudinal direction, depending upon the turning direction of the worm gear 38 , 38 ′. This reaction force is home internally in the housing 40 , 40 ′, and in particular on the interior components of the left 42 , 42 ′ and right 44 , 44 ′ cover halves. The subject invention overcomes this objectionable wear and noise phenomenon by inserting at least one, and preferably two compressible washers 66 ′ as shown in FIGS. 7-9 . It will be understood, however, that the embodiment of the invention depicted in FIGS. 5-6 includes corresponding features, although they are not visible from the illustrations. The one, or two, compressible washers 66 ′ are disposed between either one or both ends of the drive nut 54 ′ and first and second bushings 68 ′ which are disposed on opposite, longitudinally spaced sides of the drive nut 54 ′ for bearing axial loads between the drive nut 54 ′ and the housing 40 ′. The first and second bushings 68 ′ may include an anti-rotation feature which interacts with the left 42 and right 44 cover halves. In this example, the anti-rotation feature is depicted as hex flats which engage complimentary hex pockets 70 in the left 42 and right 44 cover halves. Other anti-rotation techniques may be used instead of a hex.
FIG. 8 illustrates a simplified cross-sectional view through the transmission assembly 26 ′, and depicting the compressible washers 66 ′ in a balanced, static condition. This is typical of the transmission assembly 26 ′ at rest. By comparison to FIG. 9 , however, when the worm gear 38 ′ begins to turn, as suggested by the clockwise directional arrow, reaction forces between the meshing threads and gear teeth urge the drive nut 54 ′ to press against the left side of the cover halves 42 ′, 44 ′, as viewed from FIG. 9 . The compressible washers 66 ′ react by harmoniously compressing and/or expanding to accommodate the shift. The result is a dampening effect which produces very little noise and prevents the drive nut 54 ′ from bearing harshly against either of the bushings 68 ′. Although two compressible washers 66 ′ are illustrated in FIGS. 8 and 9 , those of skill in the art will appreciate that similar functionality can be accomplished with but a single compressible washer 66 ′ disposed on either side of the drive nut 54 ′.
Preferably, the compressible washer 66 ′ is of the so-called wave washer type manufactured from a spring steel material. While preferred, however, this is not the only construction for the compressible washer 66 ′ which will produce acceptable results. Other compressible washer designs may be substituted with similar effectiveness, including compressible foam designs, coil spring designs, and the like.
Accordingly, a transmission assembly 26 , 26 ′ manufactured according to the disclosed construction, wherein a compressible washer 66 , 66 ′ or washers is shown to improve functionality, extend service life and reduce objectionable noises in the operation of a track system 18 .
The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention. Accordingly the scope of legal protection afforded this invention can only be determined by studying the following claims.
|
A track system ( 18 ) of the type used to adjust the position a supported element such as vehicular seat ( 12 ) includes a pair of base rails ( 20 ) that slidably interact with a respective pair of driven rails ( 22 ). A transverse rail ( 24 ) is attached to each of the driven rails ( 22 ) so that the driven rails ( 22 ) slide together as a unit. A motor ( 34 ) is supported on the transverse rail ( 24 ) and includes a pair of drive shafts ( 36 ) emanating from either end. The drive shafts ( 36 ) carry on their distal ends' respective worm gears ( 38 ) which are contained within a transmission assembly ( 26 ). The worm gears ( 38 ) mesh with external teeth on respective drive nuts ( 54 ) which interact with a lead screw ( 28 ) that can be oriented to either remain stationary relative to the base rails ( 20 ) or can be rotatably fixed within the driven rails ( 22 ). The drive nut ( 54 ) is prevented from causing objectionable noise and premature wear in operation by the inclusion of one or two compressible washers ( 66 ).
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates to the field of vehicles and more particularly relates to a fender attachable to a trailer or other vehicle, the fender having at least one storage compartment.
BACKGROUND OF THE INVENTION
[0002] The basic nature of modern wheeled vehicles is not much changed from their ancient counterparts. A wheel is mounted upon an axle which is in turn mounted upon the vehicle. Larger vehicles have larger axles, often with two or more wheels mounted thereupon. The very nature of a rotating wheel, especially at the speeds of a modern highway, is dangerous. To address this danger, the fender was an early innovation. The fender is, essentially, a cover that positioned over the rotating wheel so as to help prevent many forms of undesired interaction with said wheel—most often either keeping debris or a passenger or cargo from falling into the wheel or preventing debris from the road from being picked up and thrown by the wheel into the passengers, cargo or passersby.
[0003] Unfortunately, the modern fender has not changed very much from its older counterparts, in particular when aftermarket fenders are examined. The fenders in the prior art tend to be utilitarian and focus on the issue of safety. Most aftermarket fenders are mounted by direct attachment on the side walls of the vehicle. The mounting of an aftermarket fender takes a good deal of precise locating of the fender on the vehicle body. Aerodynamically, the aftermarket fender does little to improve the vehicle. As it resides a little above the wheel, the frontal sectional area is not terribly affected by an added fender, but the fender itself does not address much of the aerodynamic disturbance caused by a wheel.
[0004] The present invention is an after-market fender to be installed on an existing trailer or similar vehicle. It may, of course, be modified so that the fender may be standard equipment for such a vehicle. The fender is easily installed on the vehicle by an installed interface system supported on the vehicle. Not only does the fender provide durable storage, it also improves aerodynamics of the vehicle, thereby increasing efficiency and safety of the vehicle by reducing drag.
[0005] The present invention represents a departure from the prior art in that the fender of the present invention allows for installation on any trailer or similar vehicle with an axle with minimal alteration of said vehicle while providing safe and stable storage of items desired to be stowed. The installed interface system mounts about the axle of the vehicle and allows for both easy and sable mounting of the fender.
SUMMARY OF THE INVENTION
[0006] In view of the foregoing disadvantages inherent in the known types of fenders, this invention provides an aerodynamic fender with storage. As such, the present invention's general purpose is to provide a new and improved fender that is easy to solidly mount upon a trailer or other vehicle.
[0007] To accomplish these objectives, the fender comprises an aerodynamic shell, preferably made of aluminum, fiberglass or a composite material. The shell features a mounting interface. A corresponding vehicle located mounting interface, or “sub-assembly,” is positioned on the vehicle and features a mating interface system. Proper, one-time, positioning of the sub-assembly allows for quick and easy mounting of the fender in a centered and ideal position relative to the trailer. Five separate interfaces are disclosed.
[0008] The new fender presents a similar forward sectional area of the trailer as compared to current fender designs; but, the material is fashioned in an aerodynamically advantageous shape so as to improve aesthetics and, more importantly, reduce drag and turbulence caused by a fender. By reducing drag and turbulence, fuel efficiency and vehicle stability are increased. Also, turbulence interaction with other vehicles, known as “buffeting,” is reduced. Buffeting is created by large aerodynamic disturbances caused by the wheels of trailers and other vehicles. Buffeting is a hazardous aerodynamic condition, especially when smaller vehicles, such as motorcycles, as subjected to it.
[0009] Mounting the fender on the sub-assembly is easily facilitated by quick-detach fastening systems. These systems allow for easy removal and re-installation of the fender in cases where maintenance or cleaning are required. Each sub-assembly is also made to fragment in the event excessive sheer forces are placed on the fender, such as by a collision. In being so constructed, impacts to the fender are not translated through the entire sub-assembly to the trailer and less damage will happen to the trailer itself.
[0010] The more important features of the invention have thus been outlined in order that the more detailed description that follows may be better understood and in order that the present contribution to the art may better be appreciated. Additional features of the invention will be described hereinafter and will form the subject matter of the claims that follow.
[0011] Many objects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
[0012] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0013] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a composite image of the first embodiment of the fender system.
[0015] FIG. 1 a is a perspective view of the brackets of the first embodiment installed on a vehicle.
[0016] FIG. 1 b is a perspective view of two brackets for use with the first embodiment.
[0017] FIG. 1 c is a rear perspective view of the fender assembly of the first embodiment.
[0018] FIG. 1 d is a top plan view of the fender assembly of FIG. 1 c.
[0019] FIG. 1 e is a bottom perspective view of the Fender assembly of FIG. 1 c.
[0020] FIG. 2 is a composite image of the second embodiment of the fender system.
[0021] FIG. 2 a is a perspective view of the second embodiment of the fender system.
[0022] FIG. 2 b is a perspective view of a shell structure utilized in the second embodiment.
[0023] FIG. 2 c is a rear elevation of the shell of FIG. 2 b.
[0024] FIG. 2 d is an exploded view of the second embodiment shown in FIG. 2 a.
[0025] FIG. 3 is a composite image of the third embodiment of the fender system.
[0026] FIG. 3 a is a perspective view of the third embodiment of the fender system.
[0027] FIG. 3 b is a side elevation of the third embodiment of FIG. 3 a.
[0028] FIG. 3 c is a perspective view of the brackets used in the third embodiment of the fender system.
[0029] FIG. 4 is a composite image of the fourth embodiment of the fender system.
[0030] FIG. 4 a is a perspective view of the fourth embodiment of the fender system.
[0031] FIG. 4 b is an alternate bracket for use in the fender system of FIG. 4 .
[0032] FIG. 4 c is a key system for use with the embodiment of FIG. 4 .
[0033] FIG. 4 d is an alternate key system for use with the embodiment of FIG. 4 .
[0034] FIG. 5 is a composite image of the fifth embodiment of the fender system.
[0035] FIG. 5 a is a perspective view of brackets for use with the fifth embodiment mounted upon a vehicle.
[0036] FIG. 5 b is a perspective view showing the construction of the brackets of FIG. 5 a.
[0037] FIG. 5 c is a perspective view of the brackets of 5 a, with rubberized cushions installed.
[0038] FIG. 5 d is a perspective view depicting the brackets of FIG. 5 a interfacing with a fender assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] With reference now to the drawings, the preferred embodiment of the fender is herein described. It should be noted that the articles “a”, “an”, and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise.
[0040] With reference to Figures in general, the fender system comprises the compartmentalized fender and a mounting system attached to the vehicle. Five different embodiments are disclosed. Each embodiment has some common features. First, every embodiment has an isolation system, usually some form of rubberized cushion between the fender itself and the mounting system. These cushions isolate the fender from road shock and other jarring forces. Second, each fender has an adjustable height feature in order to accommodate different wheel sizes. The adjustable height is usually at least one block which is mountable between the fender and the mounting system. Each mounting system may be fitted with lighting for enhanced safety. The internal storage structure may be configured in any advantageous arrangement and may be constructed to accommodate specific items, such as extra fuel tanks, tools and cargo organizers. They may also be constructed to encapsulate their contents in the event of an accident. Each system features either tool-less or minimal tool mounting of the fender to the mounting sub-assembly in a quick and intuitive manner. Each fender body may be manufactured with collapsible body panels, similar to car fenders.
[0041] FIG. 1 depicts the first embodiment of the fender and mounting assembly. The mounting sub-assembly comprises two or more vertical L-brackets, as shown in FIGS. 1 a and 1 b. It is readily realized that the L-bracket may be replaced with a T-bracket, with the extra leg protruding under the vehicle and being attached thereto, for additional stability. For purposed of this Application, the term “L-bracket” shall be defined as including T-brackets or any other bracket which includes an L-shaped portion. The top of the each bracket is hooked upward. Rubberized isolation strips back each bracket and hook. The brackets are pre-mounted to the vehicle. Positioning the brackets is relatively easy and required simple mathematical calculation. The fender body features two rear collars and two lower divots directly underneath each bracket ( FIGS. 1 c and 1 d ). The brackets are slid behind the hooks while the divots rest on the lower bracket leg. A peg interface maybe provided for the divots and lower L legs, as shown in the FIG. 1 e. The peg or locating pin is shown to be on the underside of the fender while a corresponding hole is shown on the lower bracket leg; however, this may be reversed or the peg may be replaced with a fastening bolt.
[0042] The second embodiment, shown in FIG. 2 , is a three-part system. The first component is a plurality of at least one anchor mounted to the vehicle body, FIG, 2 b. Like the brackets in the first embodiment, positioning is a matter of simple math. Each anchor features a push-button locking system where a central button is pushed and lateral teeth are drawn into the anchor body. An exterior shell is positioned over the anchors, with provided holes accommodating each anchor and the rims of said holes providing mating interfaces for the anchor teeth. The shell is shaped and sized to accommodate an inner drop-in box for storage ( FIG. 2 d ). The shell features a cage substructure for durability and impact protection ( FIGS. 2 a and 2 c ). It should be noted that the shell and drop-in box concept may be adapted to any of the disclosed mounting embodiments.
[0043] The third embodiment, shown in FIG. 3 , features a mountable lower frame as a sub-assembly. The frame fits about the wheel well of the vehicle and features an arcuate fender support with lower support ledges ( FIG. 3 c ). The fender body is then mounted upon the fender ledges and fender support ( FIGS. 3 a and 3 b ). It should be noted that an appropriate existing fender could be used as a fender support; or, the fender support could be positioned over or in place of an existing fender. The fender body is then fastened to the fender support through conventional means.
[0044] The fourth embodiment, shown in FIG. 4 , is related to the third in that it utilizes a similar fender support. This embodiment, however, also utilizes one or more back interfaces ( FIG. 4 a ). The depicted interfaces are male and female sliding blocks and frames keyed to fit one another. Any shape whereby the blocks may be keyed to each other, such as a dove-tail design, can be utilized ( FIGS. 4 c and 4 d ). One set of blocks or frames is positioned on the vehicle in a manner to interface with the mating set on the fender body (usually the frames being on the vehicle). A rubberized cushion may also be positioned between each block and its attached structure. An L-bracket may also be used in this embodiment ( FIG. 4 b ).
[0045] The fifth embodiment, shown in FIG. 5 , utilizes two right angular brackets on either side of the wheel ( FIG. 5 a ). The brackets are essentially two right triangles formed at right angles to each other ( FIG. 5 b ). It should be readily appreciated that a third triangle or other structure may be utilized in a manner similar to a T-bracket. Once mounted, the brackets are positioned to interface with similar triangle structures on the back of the fender ( FIG. 5 d ). As depicted, the vertical triangles face opposite directions, ideally hypotenuse outward. This arrangement automatically centers the fender on the brackets. The fender may then be fastened with bolts or other conventional means. As with other embodiments, a rubberized spacer is applied between the brackets and the fender for vibrational dampening ( FIG. 5 c ).
[0046] One other potential feature of the invention is the positioning of the mounting means or brackets on a relatively stiff sheet of cardboard in such a manner as to pattern mounting on the vehicle. This pattern, then, may be positioned relative to the wheel in an advantageous manner without having to measure each bracket separately. This method reduces installer error and provides uniform mounting over all wheels.
[0047] Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.
|
A series of fender systems for vehicles is disclosed. Each embodiment utilizes a separate mounting assembly by which a fender assembly may be attached to a vehicle. The fender assemblies in each system reduce drag and buffeting caused by current fenders in the art.
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates generally to storing food and, more particularly, to a method and apparatus for dating and storing perishable food.
BACKGROUND OF THE RELATED ART
[0002] [0002]FIG. 1 is a fanciful depiction of a food item 200 being stored in a food container 205 and then stored in a refrigerator 220 . The food item 200 is intended to represent all variety of food items, not just leftovers. The food container 205 is shown as a plastic storage container, but food containers relevant to this invention include all variety of containers such as the original retail packaging, boxes, cartons, plastic bags, plastic wrap, foil, bottles, jars, Tupperware™, Corningware™, and so on. The refrigerator 220 is intended to represent any suitable storage arrangement including refrigerated storage, frozen storage, and dry storage (e.g. a pantry or a wine cellar).
[0003] [0003]FIG. 2 is a fanciful depiction of leftovers 200 first having been placed into a food container 205 consisting of a plastic bowl 211 and then sealed with a lid 212 . As is often the case in restaurants and homes alike, conspicuously missing from the food container 205 is any indication of the date of storage.
[0004] The safe and cost efficient storage of perishable foot items is a problem for consumers and business owners. The problem arises from the fact that it takes too much effort to date the perishable food items before they are stored so that later, when the item is being considered for use, an informed decision can be made as to its freshness and suitability for use or its qualification for disposal.
[0005] Some restaurant operators, for example, try to date perishable food items by hand-writing the date of storage onto an adhesive label peeled from a supply of blank labels. That approach, however, is fraught with difficulty in that it takes some degree of effort and is subject to human error and human oversight. Some employees, in other words, are apt to omit this labeling step because of the time and effort involved. In addition, it is sometimes difficult to read a particular person's writing.
[0006] Consumers are even more likely to store perishable food items in a haphazard manner—applying the time tested “smell test” at a later date rather than relying on any date information. Some consumers endeavor to manually label their perishable food items, using an indelible pen, for example. Consistently labeling of this nature is hit and miss at best. Moreover, while a plastic bag may be written on directly, it is not practical to write on a regular dishes, pots and pans, or washable and re-usable food containers like those made by Tupperware™.
[0007] The problem applies to all varieties of food items contained in all variety of food containers. Examples of perishable food items that are amenable to labeling include: packaged meat (beef, poultry, and fish); fresh and purchased juices; home cooked food and leftovers that are stored for later use in the freezer or in the refrigerator in their original containers or in plastic bags, plastic containers, or the like; previously frozen items that have been thawed and must be used within a reasonable period of time; and so on and so forth.
[0008] Some food items do come with a “use by” or “open by” date, but that is often not the case and, even when that date it provided, it is often not useful for providing date information because the food item (e.g. milk) is used as an ingredient in another dish that is then stored in a new food container.
[0009] Prior inventors have developed systems related to storing perishable food items. For example, in U.S. Pat. No. 5,487,276 entitled “FOOD INVENTORY SYSTEM”, the inventors Namisniak et al. disclose a method and device that is directed to tracking the “eat by” date of multiple food items using a multi-line device with multiple countdown counters. The Namisniak et al. device is perhaps overly complicated for the task at hand.
[0010] General purpose labeling machines certainly exist, but they require a great deal of effort to operate and are unlikely to be used. In other words, it is impractical to expect somebody who is right then and there ready to store a perishable food item to take the time and effort to type in the date and time by successively pressing a series of alphanumeric buttons and then press yet another button to print the label, all while holding the food item that is to be stored. The user could, of course, put the food item down and go through the tedious process of preparing a label on a general purpose labeling machine, but as with the “manual” labeling approaches described above, the time and effort requirements of this approach make it likely that the label with never be made.
[0011] Even if one were determined enough to apply a conventional, tediously prepared label from a currently available labeling machine, there is also the problem of later removing that label from the food container.
[0012] There remains a need, therefore, for method and apparatus for dating and storing perishable food that addresses and resolves the above-described problems.
SUMMARY OF THE INVENTION
[0013] In a first aspect, the invention resides in a food container labeling apparatus adapted for producing a dated label that is applied to a food container, comprising: a power supply; a supply of printable media; a printing means connected to the power supply for printing indicia on the printable media; a clock means for providing a current date; a single-action actuator that, in response to performance of only a single action, generates an actuator control signal; and a controller for producing a dated label in response to the actuator control signal by causing the printing means to print the current date on the printable media.
[0014] In a second aspect, the invention resides in a food container labeling apparatus adapted for producing a dated label that is applied to a food container, comprising: a power supply; a supply of printable media that is water soluble; a printing means connected to the power supply for printing indicia on the printable media; a clock means for providing a current date; a button and an associated momentary contact switch for immediately generating an actuator control signal in response to a single-action actuation of the button; and a controller for producing a dated label in response to the actuator control signal by causing the printing means to print the current date on the printable media, whereby dated label communicates a date associated with the food container and dissolves away when the food container is washed.
[0015] In a third aspect, the invention resides in a method of printing a dated label for storing perishable food comprising the steps of: maintaining information regarding a current date; and in response to only a single action being performed printing a dated label bearing indicia that is indicative of the current date, whereby the dated label is printed without a user having to know the current date and without having to type in indicia a that is indicative of the current date.
[0016] In a fourth aspect, the invention resides in a method of storing perishable food comprising the steps of: providing a food storage container; single-handedly and substantially-immediately actuating a label printing apparatus to produce a dated label; single-handedly grasping the dated label; applying the dated label to the food storage container; and storing the food storage container with the dated label for later consideration for use based on the dated label.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The just summarized invention can be best understood with reference to the following description taken in view of the drawings of which:
[0018] [0018]FIG. 1 is a fanciful diagram illustrating how a perishable food item (a leftover sandwich in this case) is placed into a food container (a plastic bowl in this case) and then stored (in a refrigerator in this case);
[0019] [0019]FIG. 2 is a diagram showing how perishable food is typically placed into a food container and then sealed for storage without any date;
[0020] [0020]FIG. 3 is block diagram of a first preferred apparatus according to this invention;
[0021] [0021]FIGS. 4A, 4B, and 4 c are depictions of dated labels created by the apparatus of FIG. 1;
[0022] [0022]FIG. 5 is a perspective view of a container bearing a dated label as produced by the apparatus of FIG. 3;
[0023] [0023]FIGS. 6A, 6B, 6 C, and 6 D are a series of perspective views showing how a user may conveniently push a single-action actuator to produce a dated label, grasp the dated label, apply the dated label to the container, and then store the container with dated label in a refrigerator;
[0024] [0024]FIGS. 7A, 7B, 7 C, and 7 D are a series of close-up perspective views corresponding to FIGS. 6A, 6B, 6 C, and 6 D, showing more clearly the steps of push-grasp-apply-and-store;
[0025] [0025]FIG. 8 is a perspective view of the first preferred labeling apparatus of FIG. 3;
[0026] [0026]FIG. 9 is a perspective view of the labeling apparatus of FIG. 8 with the hinged door open and the battery cover removed;
[0027] [0027]FIG. 10 is an exploded perspective view of the labeling apparatus of FIG. 8 with its hinged door open and its ribbon cartridge removed, and with its battery cover open and its batteries removed;
[0028] [0028]FIG. 11 is a rear perspective view of the labeling apparatus of FIG. 8;
[0029] [0029]FIG. 12 is a rear, partially exploded perspective view of the apparatus of FIG. 8 with its hinged door open;
[0030] [0030]FIGS. 13A, 13B and 13 C are perspective views of the preferred single-action actuator 70 and two alternative actuators 170 and 270 ;
[0031] [0031]FIGS. 14A, 14B, 14 C and 14 D are perspective views of various embodiments of the apparatus including a preferred embodiment 10 that is magnetically secured to a refrigerator, a built-in embodiment 110 that is integrated into the refrigerator, a counter-top embodiment 210 , and a plug-in embodiment 310 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] [0032]FIG. 3 is block diagram of a first preferred food container labeling apparatus 10 according to this invention. The preferred labeling apparatus 10 , and methods of use related thereto, uniquely enable a single-action generation of a dated label 43 in a quick and efficient, nearly effortless manner that makes it more likely that users will consistently label food containers that hold perishable food items.
[0033] Many embodiments are possible. As shown in FIG. 3, however, the preferred apparatus generally comprises a housing 20 that contains a power supply 30 , a supply of printable media 40 (e.g. a continuous supply of labels provided in a rolled tape format), a means 50 for printing indicia on the printable media 40 , a means 60 for providing a current date (and perhaps time) (e.g. a so-called clock/calendar), a single-action actuator 70 that, in response to performance of only a single action, generates an actuator control signal 71 , and a controller 80 for producing a dated label 43 in response to the actuator control signal 71 by causing the printing means 50 to print the current date provided by the clock means 60 onto the printable media 40 and, thereby, producing a dated label 43 from an output slot 90 .
[0034] [0034]FIGS. 4A, 4B and 4 C depict representative date and time indicia that may be printed on a dated label 43 produced in accordance with this invention. As shown, the dated label 43 may contain just the date, or it may contain the date and time. The exact format is not critical, those shown being but three examples. It is possible to automatically print other indicia along with the date and/or time, but it is important to not require any significant effort on the part of the user during use of the apparatus 10 .
[0035] [0035]FIG. 5 depicts a food storage container 205 that is like those shown in FIGS. 1 and 2, but it now carries a dated label 43 that was conveniently and quickly produced in accordance with the apparatus and method of this invention. As a result, the food storage container 205 may now be safely stored for later consideration as to safe and timely use.
[0036] Further details as to the construction and operation of the preferred food labeling apparatus 10 may be considered by returning to FIG. 3.
[0037] The power supply 30 may be of any suitable design including one or more batteries 12 (ee FIGS. 10 and 12) or direct AC power from a conventional outlet (See FIG. 14D). It is also possible, of course, to provide power via a remote transformer that connects to the apparatus 10 via a suitable jack (See FIG. 8 and the input jack labeled “AC Input”). Where batteries are used, the type of battery is immaterial. The batteries 12 , for example, may be rechargeable batteries of nickel cadmium construction or nickel metal hydride construction or single use batteries of alkaline construction.
[0038] The printable media 40 is preferably provided in the form of a continuous ribbon of label material 41 contained, for example, in a cartridge 100 (See FIGS. 9 and 10) for easy replacement. The dated label 43 may be cut from the label material 41 without any leftover substrate or the dated label may be peeled away from a substrate (that may or may not remain in the apparatus 10 ). In either case, the dated label 43 should be ready for immediate application to the food container 205 . The label material should have a peel-off adhesive so that it is easily removed from the food container or, alternatively, be fabricated from water soluble materials so that the dated label 43 will dissolve while the food container is held under running water or is being washed in the dishwasher.
[0039] The preferred means for printing comprises a printing mechanism 50 of any desired construction that is suitable for use with the chosen media 40 . The precise construction of the printing mechanism does not form a part of this invention as the implementation details of such mechanism are well known or readily ascertained by those of ordinary skill in the art. The printing means 50 , in fact, should be regarded as including printing mechanisms of yet to be invented construction because it is only necessary that the printing mechanism respond to the controller 80 (discussed above and in more detail below) by printing the appropriate indicia onto the printable media 41 in order to create the dated label 43 .
[0040] The clock means 60 for providing a current date preferably consists of an ordinary clock/calendar that outputs a digital representation of a date and/or time. The clock means 60 may be powered by the power supply 30 or, given its relatively low power usage relative to that of the print mechanism 50 , it may have its own separate power supply in order to reduce the probability of it having to be reset. The time, as opposed to the date, may be regarded as optional, but it is likely that consumers will find the clock useful if displayed for ready observation.
[0041] The single-action actuator 70 , as noted above, generates an actuator control signal 71 in response to performance of only a single action. One push of the button will substantially immediately dispense a dated label 43 that can then be applied to any desired food container. In the preferred embodiment of the food labeling apparatus 10 , the single-action actuator 70 comprises a single button in the form of a momentary contact, normally-open switch. As suggested by FIGS. 13A, 13B, and 13 C, however, many different varieties of single-action actuators are possible. FIG. 13A shows the single-action actuator 70 in the form a a single-button single-touch switch 70 like that shown in FIG. 3. FIGS. 13B and 13C, however, depict two alternative embodiments. FIG. 13A shows a single-action actuator 170 consisting of two buttons 171 and 172 that must be simultaneously depressed . FIG. 13C shows a single-action actuator 270 with a single button that must be tapped twice in rapid succession. Many other varieties of single-action actuators, of course, may be used in accordance with the teaching of this invention. For example, the labeling apparatus 10 could be nearly hands-free by including suitable circuitry for responding to a spoken sound such as “print label”.
[0042] The controller 80 , as shown, receives date and/or time information provided by the clock/calendar 60 and the actuator control signal 71 provided by the single-action actuator 70 . In operation, and in response to user's actuation of the single-action actuator 70 and the resulting actuator control signal 71 , the controller 80 communicates with the printing mechanism 50 and commands it to print indicia corresponding to the date and/or time onto the dated label 43 . The controller 80 also communicates with a display 11 (discussed below) in order to present the user with the current date for setting and/or confirmation purposes. The preferred controller is a microcontroller with sufficient ROM and RAM as required, but any suitable control electronics may suffice such as, but not limited to, various programmable logic devices.
[0043] As also shown in FIG. 3, the preferred apparatus 10 further comprises an optional display 11 that may be used for inputting or adjusting the date and time and for later confirming the date and time is correct. The intended display 11 is an LCD display, but if a display is included, any suitable display may be used.
[0044] Where the printable media 40 comprises a continuous ribbon of label material 41 , as presently preferred, the output slot 90 may also contain means 91 for separating the dated label 43 from the continuous ribbon of label material. Suitable separating means 91 include an electromechanical cutting mechanism (automatic) or a serrated tear bar (manual). Other approaches are possible.
[0045] [0045]FIGS. 6A, 6B, 6 C and 6 D, and corresponding closeup FIGS. 7A, 7B, 7 C and 76 D, are a parallel series of perspective views showing a method of storing perishable food that is enabled by the food labeling apparatus 10 of this invention. The method, in shorthand, uniquely and conveniently consists of “push”, “grasp”, “apply” and “store”. Significantly, the method is so convenient that users are likely to actually label the food items in a continuous and consistent manner. The result is more efficient and safe use of food items. In other words, by having a dated label 43 on the food container 205 , it will be easy to later decide whether to eat the leftovers or throw them away.
[0046] [0046]FIGS. 6A and 7A show how a user may conveniently push the single-action actuator 70 to produce a dated label 43 . Significantly, due to the single-action actuator 70 , the user may be holding a food container 205 in one hand and activate the single-action actuator 70 with his free hand.
[0047] [0047]FIGS. 6B and 7B show how a user may then grasp the dated label 43 , again all while holding a food container 205 . The dated label 43 may emerge pre-separated, may be cut using an automatic electromechanical separator 91 , or may require the user to pull the dated label 43 along a serrated edge 91 as a continuation of the grasping step.
[0048] [0048]FIGS. 6C and 7C show how the user may apply the dated label 43 to the container 205 , again with the user's free hand.
[0049] [0049]FIGS. 6D and 7D, finally, show how the user may store the container 205 with dated label 43 in a refrigerator 220 . The method, again, is uniquely as convenient as push, grasp, apply and store.
[0050] [0050]FIGS. 8, 9, 10 , 11 and 12 are various views of the internal and external details of a presently preferred food labeling apparatus 10 according to this invention. As shown, the preferred food labeling apparatus 10 is relatively small in size and generally comprises a housing 20 that contains the functional blocks discussed above and depicted in FIG. 3. Because the preferred apparatus 10 is small in size, and because it contains the single-action actuator 70 discussed above, a person can hold a food container in one hand while printing a dated label with the other. It may be convenient, however, to place or mount the apparatus in certain convenient location as depicted in FIGS. 14 A- 14 C discussed below.
[0051] As shown in FIG. 8, the housing 20 includes a side wall portion 21 , a fixed upper portion 22 , and a hinged door portion 23 . The single-action actuator 70 is present at the upper left of the fixed upper portion 22 . The display 11 is immediately below the actuator 70 . The output slot 90 is located in the housing's side wall 21 . The hinged door portion 23 contains a window 24 to permit the user to see how much labeling media remains.
[0052] [0052]FIG. 9 shows the apparatus 10 of FIG. 8 with the hinged door portion 23 pivoted open, thereby revealing the preferred embodiment's use of a disposable cassette 100 similar to the cassettes already used in other general purpose labeling machines. The cassette 100 is preferably designed so that the label's backing will be peeled off and returned to the cassette 100 , leaving the user with a sticky, ready-to-use label. The printing mechanism 50 is visible adjacent to the cassette 100 , next to the output slot 90 .
[0053] [0053]FIG. 10 is an exploded view of the labeling apparatus 10 with the cassette 100 floating above the advance mechanism (not numbered), and with a plurality of batteries 12 and a suitable battery compartment cover 24 floating below the overall apparatus.
[0054] [0054]FIG. 11 is a perspective view of the rear of the labeling apparatus with the battery compartment cover 24 in place and FIG. 12 is a rear perspective view with the hinged door portion 23 opened and with the battery compartment cover slid to the right to expose the batteries 12 .
[0055] The preferred labeling apparatus 10 depicted by FIGS. 8 - 12 is but one design. The overall appearance and the location of and specific type and construction of its constituent elements may be varied without departing from the scope and spirit of the below appended claims. For example, the labeling apparatus 10 could be designed to incorporate decorative faceplates that come in different colors or themes. In addition, an industrial version more suitable for commercial restaurant use could be constructed with more regard to durability than to aesthetics.
[0056] [0056]FIGS. 14A, 14B, 14 C and 14 D depict various further embodiments of a food labeling apparatus according to this invention.
[0057] [0057]FIG. 14A, in particular, shows the first preferred labeling apparatus 10 secured to refrigerator by a suitable means. Examples includes adhesive tape or magnetic strips.
[0058] [0058]FIG. 14B shows a second embodiment of a labeling apparatus 110 incorporated into the refrigerator itself.
[0059] [0059]FIG. 14C shows a third labeling apparatus 210 that resides on the surface of a countertop and that is evidently battery powered. The labeling apparatus 210 may actually be the same apparatus 10 that is secured to the refrigerator, it being the user's option where to mount it.
[0060] [0060]FIG. 14D, lastly, depicts an embodiment 310 that plugs directly into an AC outlet so that it resides above the countertop and so that batteries are not needed. It would be desirable, in this context, to provide the apparatus 310 with a suitable “swing-out” plug so that the device is mounted as shown as an option.
[0061] The above description is of a preferred embodiment of the invention, the scope of which should not be limited thereby but rather should be interpreted in light of the scope and spirit of following claims.
|
Disclosed is a food labeling apparatus that contains a power supply, a supply of printable media, a clock, a controller, and a single-action actuator that, upon activation by a user, immediately produced a dated label for application to a food container and subsequent storage. The method of storing perishable food with the labeling apparatus includes the steps of maintaining information regarding a current date, and in response to only a single action being performed, printing a dated label bearing indication that is indicative of the current date. The preferred single-action actuator is a momentary contact, normally-open switch.
| 1
|
This is a continuation of co-pending application Ser. No. 141,294, filed on 1/5/88 now abandoned.
FIELD OF INVENTION
This invention relates to a separating apparatus for separating an admixture of materials by size, and more particularly to improvements in a disc screen that improves performance and reduces maintenance thereof.
BACKGROUND OF THE INVENTION
Disc screens as contemplated by the present invention are frequently used as one stage of a multi-stage materials separating system. Such a multi-stage system is illustrated in co-pending application, Ser. No. 841,168. FIG. 9 is a plan view of the disc screen which is also indicated by reference 56 in FIG. 1. Whereas the illustrated system is designed to separate out an intermixture of such debris as wood, rock and dirt accumulated in a lumber mill yard, the disc screen has further application for separation of refuse and all manner of materials where separation by size is an objective.
In general, the discs of a disc screen are mounted on shafts at spaced positions along the length of the shaft thereby forming disc rows. The shafts or disc rows are mounted in parallel with the discs of one disc row interspersed between the discs of adjacent (before and after) disc rows. Rectangular openings are formed by the spacing between the adjacent overlapping discs of adjacent disc rows in one dimension and by the spacing between adjacent shafts in the other dimension. Materials passing through the disc screen have to fit down through these openings.
The discs are rotated on the shaft in a direction from an inlet end to an outlet end. An admixture deposited on the inlet end of the disc screen will be rolled by the discs toward the outlet end with materials of the acceptable size passing through the screen and the rejected materials being rolled toward and off the outlet end of the screen.
Problems encountered by such disc screens, which are the object of the present invention, are twofold. Materials in such admixtures come in all manner of sizes, shapes and consistencies, i.e. they can be rock hard or paper soft. As the materials are rolled off one row of discs and onto another, there is a tendency for certain of the materials, i.e. those that are just oversized for the screen opening, to become lodged between the rows. The edges of certain of the discs are sometimes scalloped or lobed to assist in gripping and moving the materials along the rows. At any rate, the problem is not particularly significant except at the ends of the disc rows. If material becomes lodged between a last disc in the row and the sidewall of the screen housing, it can become jammed. Unjamming may require shutting the operation down and manually removing the jammed materials.
As concerns the second problem; the shaft-to-shaft dimension as described above as one of the dimensions for the screen openings, is actually made up of sleeve sections that surround an inner driven shaft. The sleeve sections also separate and space the discs along the shaft length. Previously, these sleeve sections were supported on the shafts by rails running along the length of the shaft welded directly to the discs. The problem encountered with this structure is that any deformity of the discs (as when occasionally a disc is severely struck by a rock-hard object) would skew the sleeve section and create an interference between the close fitting sleeve sections and the aligned discs of the adjacent rows of discs.
BRIEF DESCRIPTION OF THE INVENTION
The problem of jamming at the shaft ends has been largely eliminated by the provision of end discs that are placed adjacent the sidewall or even recessed slightly into the sidewall to prevent materials from entering between the end disc and side wall. Because the end discs will be aligned as between adjacent shafts, they are reduced in diameter as compared to the interspersed discs.
The problem of skewing the disc spacers is largely eliminated by providing the spacers or sleeve sections as separate elements. The sleeve sections typically have a greater inside diameter than the inner shaft and thus an interior gusset is provided as a strengthening rib for the sleeve section. The gusset is fit to the inner shaft in the same manner as the disc and rotates with the disc. The gusset-strengthened sleeve section not only is unaffected by damage to the disc, even in instances when the sleeve sections are directly impacted, these strengthening gussets resist deformation of the sleeve section.
The invention will be more fully appreciated by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic side view illustrating a screening disc of the present invention in operation;
FIG. 2 is a schematic top view of the screening disc of FIG. 1;
FIG. 3 is an enlarged view of a corner portion of the disc screen as if including an area such as encircled IN FIG. 2;
FIG. 4 is a view as taken on view lines 4--4 of FIG. 3;
FIG. 5 is an exploded perspective view illustrating the arrangement of discs and spacers of certain of the rows of discs, e.g. the third row right-to-left as illustrated in FIG. 3;
FIG. 6 is an exploded perspective view illustrating the arrangement of discs and spacers of the first row of FIG. 3; and
FIGS. 7-10 are alternate embodiments of the disc screen.
DETAILED DESCRIPTION
Referring to FIG. 1, an admixture of material 10 is conveyed by a conveyor 12 (see arrow 13) and deposited on a disc screen 14, including rotating discs 16 rotating in a counterclockwise direction as indicated by arrow 18. The rotating discs move the admixture 10 along the length of the disc screen as indicated by arrow 20. The smaller size materials 10s of the admixture 10 drop through the screen (between the discs) and the larger size materials 10m are conveyed by the discs 16 to be directed off the disc screen and onto a second conveyor 22 (arrow 23) or other processing components.
A plan view of the disc screen is illustrated in FIG. 2 and arrow 20 indicates the direction of movement of the admixture (not shown) along thedisc screen. FIG. 3 which is an enlarged view of the lower right-hand corner of FIG. 2 (as indicated), and FIG. 4, which is a side view of the FIG. 3 apparatus (as indicated by view lines 4--4), illustrate in detail the features comprising the present invention. The exploded perspective view of FIGS. 5 and 6 will also aid the reader in understanding these features.
The disc screen frame includes side rails 24 and end rails 26. A plurality of shafts 28 are rotatably mounted in bearings 30 at the side rails 24. Ina specific example of a disc screen that was produced and which will be referred to in setting forth dimensions hereafter, the screen was made six-feet wide and ten-feet long with nine shafts 28 mounted in parallel arrangment at one-foot centers along the disc screen length. The two end shafts were mounted one-half foot inwardly from each end.
The disc screen, as illustrated, has an inlet end 32 and an outlet end 34 (see FIG. 2), the difference being the initial disc and spacer arrangementon the first row of discs (on the first shaft 28) at the inlet end of the screen, which is the far right shaft shown in FIGS. 1,2,3 and 4. Not shownis a slope sheet which is commonly utilized for delivery of the materials onto the disc screen but, which is not shown herein. It is considered unnecessary for an understanding of the invention. The arrangement of the first disc row is specifically illustrated in FIG. 6. It is not a necessary arrangement for the invention, and thus the more typical arrangement of the other rows will be explained first. However, the readershould understand that this first row has a definite benefit and in certaincircumstances, two or more of the "first" rows may be provided with this "closed-in" arrangement which will be more specifically described in a later section.
Reference is made to the third row of discs which is duplicated at alternate row positions, i.e. the third, fifth, seventh and ninth rows arethe same. Arrow 36 indicates this third row in FIG. 3. This arrangement is specifically illustrated in the exploded view of FIG. 5. Discs 38 are provided with centered square holes 40 that are sized to fit the cross section of shaft 28 and thereby key 5 the discs to the shaft. The shaft 28is consistently dimensioned along its length so that the disc 38 is free toslide on the shaft 28. There are a total of twelve discs 38 spaced along the length at five-inch intervals. The positions of the discs on the shaftare affixed by spacers.
The spacers in the form of sleeve sections 42 between the discs 38 have a five-inch length and surround the shaft 28 as illustrated. Each sleeve section 42 has an inner diameter greater than the cross section of shaft 28 and is fitted with an internal gusset 44, welded in place in the sleevesection and provided with a square-shaped opening 40 like that of the discs38. The spacers or sleeve sections 42 are similarly free to slide along shafts 28. Disc 46 to be later explained in more detail, is provided at each end of shaft 28 and is also provided with square-shaped openings 40.
The arrangement of the even numbered rows (the second, fourth, sixth and eighth rows) are similar to that of row 36 except that the spacing sleeve section 48 between the end disc 46 and the first full-sized disc 38 is shortened as compared to spacer 42 to position the discs 38 thereafter intermediate of the disc positions on the rows 36, i.e. they are interspersed to allow overlapping of discs in adjacent rows. The length ofthese end spacers 48 are about one-half or slightly less than half the length of spacers 42 (i.e., whatever is required to position the discs along the shaft length at about the mid-point of the positions of the discs in alternating rows, three, five, seven and nine). The end sleeve sections or shortened spacers 48 are similarly provided with strengtheningor stiffening gussets 44 (shown in dash lines in row two, row two being indicated by reference number 50 in FIG. 3).
As will be obvious from reference to FIG. 3, the end discs 46 are substantially smaller in diameter than discs 38. This is because rather than being offset in adjacent disc rows, the discs 46 are positioned in close proximity, e.g. tight up against the straight side rail 24 and, consequently, in alignment one with the other. The shafts 28 are on one-foot centers and thus the maximum diameter permitted for the discs 46 is about one foot. Of course, some clearance is desirable and a one-fourthto one-half inch space between the discs is suggested, making the discs approximately eleven and three-fourths to eleven and seven-eights inches in diameter.
The smaller discs 46 do not match up with adjacent discs 38 positioned inwardly on the same shaft because of the difference in diameter, notably they are mismatched in height as apparent by reference to FIG. 4. The disc46 is, however, positioned tight against the bearing 30 so as to maintain minimum clearance 52 with the side rail. Materials are prevented by the end disc 46 and the adjacent or mated disc 38 function to effectively liftand move materials that would likely cause jamming in the prior disc screenapparatus.
Alternate forms of the end disc feature are available, examples of which are illustrated in FIGS. 7 and 8. FIGS. 7 and 8 are top and side views showing the discs 46 set into recesses 53 so as to be partially recessed in the side rail 24. Insetting the discs avoids clearance 52 between the rail 24 and disc 46 (see FIG. 3).
FIGS. 9 and 10 illustrates an ambodiment where the side rail 24 is configured to permit alternating overlapping larger end discs 46a, i.e. which are the same dimensions as discs 38. Whereas such variations of discarrangements have been tried, they have not been found to provide the benefits of the smaller in-line discs of the present invention.
Reference is now made to the first row indicated by arrow 56 in FIG. 3. This first row disc-spacer arrangement is unique in the disc screen. The reason is that this first row does not have an adjacent disc row on the inlet side in that it is placed adjacent front end rail 26. In a typical disc-spacer arrangement like row 36, with the interspersed discs of an adjacent row of discs, the screen hole opening is less than two and one-half inches. In row 56, however, at the inlet side of the shaft 28, that same spacing is determined by the spacing between the discs 38 on thesame shaft. If the arrangement of this row were similar to that of the third row, the disc screen openings at that inlet side would be up to fiveinches. Note that the problem doesn't exist at the outlet end row (see FIGS. 1 and 2) because the end rail fits under the last row of discs. Material carried along by the rotating discs simply is rolled over the endrail onto the conveyor 22.
The normal five-inch spacing between discs 38 is modified for the first row56 as illustrated in FIGS. 3 and 6. At the position where typically a disc 38 is provided for row three i.e. aligned with spacer 42 of row two, in row one a pair of discs 38 are provided. Thus, the number of discs 38 are doubled for end shaft 28. However, the one-half inch disc thickness by itself is not sufficient to fill in the two and one-half inch extra gap created by the missing interspersed discs of an adjacent row. Thus the paired discs 38 are separated by an additional spacer 58. Spacer 58 similarly includes a gusset 60 (enlarged over that of gussets 44) which isprovided with the same center opening 40. Between the paired discs 38 is provided a shortened spacer sleeve 42a, which, except for being shortened,functions like the spacers 42 of the previously described rows of discs (and is very close to if not the same as the length of spacers 48).
The reader will thus appreciate the arrangement of the nine rows as follows. For the first row (reference 56), shaft 28 is fitted with an end disc 46, a spacing washer 62 and a single disc 38. This arrangement sets up the appropriate interspersing of the double disc configuration between discs 38 in row two. Thus, in alternating fashion thereafter, a short spacer 42a is followed by a composite of a disc 38, a spacer 58, and a second disc 38, (referred to as as doubledisc arrangement), followed againby a spacer 42a, followed by a double disc arrangement, and so on. At the opposite end, the start-up sequence previously described is repeated including an end disc 46, washer 62 and single disc 38.
The second, fourth, sixth and eighth rows are as indicated in FIG. 3, with an end disc 46 followed by a shortened spacer 48 (similar to that of 42a),followed in alternating fashion by discs 38 and spacers 44. Again, the opposite end is similar with the end disc 46 being preceded by the shortened spacer 48. The rows three, five, seven and nine are a slight variation to that of rows two, four, six and eight, in that the end discs 46 are immediately followed by alternating ones of the spacers and discs. It should be noted that row one has a total of twenty-six discs, rows two,four, six and eight each have thirteen discs, and rows three, five, seven and nine each have twelve discs.
The various dimensions and sizes set forth can, of course, vary. The referred to disc screen that was constructed in accordance with this invention (many of the dimensions and specific features thereof having been previously described) included discs 38 having a one-half inch thickness and a seventeen-inch outside diameter. The discs were spaced five inches apart along the same row and two and one-half inches apart from an interspersed disc. The spacer 42 have a wall thickness (for rigidity) of five-eighths inch thick with a six and three-fourths inch outside diameter. The shafts 28 were placed on one-foot centers so that the spacing between the outer edges of discs 38 and the outside walls of spacers 42 on adjacent rows was less than one-fourth inch whereby in rotation the discs 38 pass in close proximity to spacer 42. Certain of thediscs 38 were provided with lobes 64 (shown in dash lines in FIG. 4) as by scalloping to facilitate movement of the material along the disc screen.
The smaller spacers 42a and larger spacers 58 for the first row 56 were twoand one-half inches in length (the larger spacers 58 having a twelve and three-fourths inch diameter). The cross section of the shaft 28, and accordingly the hole 40 provided through the gussets and the discs, was approximately a square shape of four inches to a side.
The invention herein described is believed to solve significant problems that have long existed for disc screens previously in use and operation. Damage to the improved discs is less likely and when damage occurs, it is far less serious. Because the discs and spacers are independently mounted to the shaft, damage is less likely because even though a disc 38 may become damaged, that damage will not likely distort the adjacent spacers, as was often the case previously. Any distortion of the spacers places thediscs 38 before and after it in jeopardy of also being damaged.
The disc screen reduces downtime by significantly reducing the likelihood of jamming along the side rails. This feature and the feature of the spacers are believed novel and those skilled in the art will readily appreciate the advantages that are provided and the application of these features to disc screens in general.
The structure of the disc screen has been somewhat simplified to avoid unnecessary complexity. Those skilled in the art will appreciate that the supporting frame around the disc rows typically involves the use of side sheets and bearing shields to facilitate maintenance and adjustment. In all cases, however, some form of side wall, like rail 24, is present and the application of the inventive feature for avoiding side wall jamming applies in the manner described. The invention is considered to encompass all these and similar variations in kind as determined by the applicable scope of the claims appended hereto.
|
A disc screen having rows of rotatable discs separated by sleeve-like spacers. Discs of adjacent rows are offset and extended to a near touching relationship with the spacers of adjacent disc rows. A supporting and rotatably driven shaft extended through each row of disc and spacers. The spacers are independently mounted to the shaft with internal strengthening gussets having keyway-type openings slidably fitted to the shaft's non-circular cross section. End discs on each shaft are mounted for close proximity to the side rails of the disc screen housing and, as aligned along the side rails, are reduced in diameter to prevent interference. The proximity of the end discs to the side rails prevent materials from being jammed against the side rails.
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates to testing tools for computer systems, more particularly to a testing tool including a testing card having different testing circuits.
DESCRIPTION OF RELATED ART
[0002] Normally, in a computer manufacturing process, testing is an important step to ensure reliability of a manufactured computer system. The testing includes both hardware and software testing for the computer system and its components.
[0003] For example, for testing an I/O port, a plurality of different testing tools including different testing circuits is required to test the I/O port. It is time-consuming to link the I/O port to different testing tools. In addition, the I/O port may be damaged during the linking to different testing tools.
[0004] It is therefore desirable to find a new testing tool which can overcome the above mentioned problems.
SUMMARY OF THE INVENTION
[0005] A testing tool for testing an I/O port includes a cable and a testing card. The cable includes a port formed at one end thereof configured for being connected to the I/O port, and a first connector formed at an opposite end thereof. The testing card includes two testing circuits and a second connector connected to the first connector. The second connector includes a slider shiftable between a first position where the second connector and a testing circuit are interconnected, and a second position where the second connector and the other testing circuit are interconnected.
[0006] Other advantages and novel features will be drawn from the following detailed description of preferred embodiments with attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an exploded view of a testing tool in accordance with a preferred embodiment of the present invention, including a cable with a first connector, and a testing card shown a front and a rear aspects thereof;
[0008] FIG. 2 is a sketch view of a first structure of the first connector of FIG. 1 ;
[0009] FIG. 3 is a sketch view of a second structure of the first connector of FIG. 1 ;
[0010] FIG. 4 is a sketch view of a third structure of the first connector of FIG. 1 ;
[0011] FIG. 5 is a sketch view of the testing card of FIG. 1 , showing a front, a back, and a top aspects of the testing card;
[0012] FIG. 6 is a sketch view of another testing card of another embodiment of the present invention, showing a front, a back, and a top aspects of the another testing card; and
[0013] FIG. 7 is a sketch view of a second connector of FIG. 6 connected to more than one port.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIG. 1 , a testing tool for testing ports of a computer system in accordance with a preferred embodiment of the present invention, includes a cable 10 and a testing card 30 .
[0015] The cable 10 includes a port 11 integrated at one end of the cable 10 . The port 11 is adapted to connect to an input/output (I/O) port (not shown) for testing. The port 11 is a serial port or a parallel port in accordance with the I/O port. A first connector 13 is integrated at the other end of the cable 10 . The first connector 13 is linked to the port 11 via the cable 10 . A type of the first connector 13 is in accordance with a type of the port 11 . If the port 11 is a serial port, the first connector 13 is a serial connector, and if the port 11 is a parallel port, the first connector 13 is a parallel connector.
[0016] The first connector 13 may have different structures. Referring to FIGS. 2-4 , three variations in the structure of the first connector 13 are shown as an example. Referring to FIG. 2 , in the first structure of the first connector 13 , the first connector 13 is a 9 pin serial connector complying with the mechanical standard of a 9 pin serial port. Pins 1 , 2 , 3 , 4 , and 5 are aligned in one line, and pins 6 , 7 , 8 , and 9 are aligned in another line. The pins 1 to 9 are electrically connected to the corresponding pins of the port 11 . Because the structure complies with the mechanical standard of the 9 pin serial port, it is convenient to test.
[0017] Referring to FIG. 3 , in the second structure of the first connector 13 ′, the pin 5 is omitted, and the pins 2 , 3 , 4 , and 6 are arranged in a row parallel to pins 7 , 8 , 9 , and 1 which are also arranged in a row. Because the pin 5 is used to connect to ground, it is omitted. The pins are aligned according to frequency of use of the pins in the test process. The pins aligned in this order can simplify a corresponding circuit on the testing card 30 .
[0018] Referring to FIG. 4 , in the third structure of the first connector 13 ″, the pins 1 to 4 and 6 to 9 are aligned in a row, and the pin 5 is omitted. The pins are aligned according to pin's sequence number, so it is easy to ascertain each pin and convenient to test.
[0019] If the first connector 13 is a parallel connector, pins of the parallel connector can be aligned in different orders, such as complying with standard structure of the parallel connector, or according to the pin's sequence number, or according to frequency of use of the pins in the test process.
[0020] Referring to FIG. 5 , the testing card 30 includes two testing circuits 35 set thereon. These testing circuits 35 are used to test different aspects of the I/O port. The testing card 30 also includes a second connector 31 adapted to connect to the first connector 13 .
[0021] The second connector 31 has a slider 33 , and a plurality of pads 315 . Each of the plurality of pads 315 is connected to a corresponding pin of the plurality of pins of the first connector 13 . The plurality of pads 315 are aligned in a same order as the pins 1 to 9 of the first connector 13 .
[0022] The slider 33 is slidable between a first position and a second position. The slider 33 includes eighteen contact pieces 31 7 with one aspect of the slider 33 having ten contact pieces 317 and another aspect having eight contact pieces 317 . The eighteen contact pieces 317 are divided into two groups with each group having nine contact pieces 317 . Each group of contact pieces 317 is connected to one of the two testing circuits for testing different aspects of the I/O port. One group of contact pieces 317 is aligned alternately with the other group of contact pieces 317 .
[0023] When the slider 33 slides to the first position, one group of contact pieces 317 contacts to the nine pads 315 for testing the I/O port by one testing circuit. When the slider 33 slides to the second position, the other group of the contact pieces 317 contacts to the nine pads 315 for testing the I/O port by the other testing circuit. By easily sliding the slider 33 , the I/O port is tested by different testing circuits. It is convenient to test the component without changing with another testing card and connecting the testing card to the component.
[0024] In the above-mentioned embodiment, the slider 33 may also be configured to slide between three or more positions, to accommodate the addition of corresponding groups of contact pieces and testing circuits.
[0025] Referring to FIG. 6 , another embodiment of a testing card 30 ′ is shown. The testing card 30 ′ includes a second connector 31 ′ connected to the first connector 13 .
[0026] The second connector 31 ′ includes nine pads 315 ′ corresponding to pins 1 to 9 of the first connector 13 respectively. The pads 315 ′ are aligned in a same order as the pins 1 to 9 of the first connector 13 .
[0027] The second connector 31 ′ further includes nine terminals 37 ′. Each of the terminals 37 ′ is connected to the corresponding pad 315 ′ respectively.
[0028] When the I/O port needs to be tested, the nine terminals 37 ′ are connected in a variety of combinations to form a desired testing circuit to test a aspect of the I/O port. For example in FIG. 6 , the second and third terminals 37 ′ are connected together, the fourth and sixth terminals 37 ′ are connected together, the seventh and eighth terminals 37 ′ are connected together, and other terminals 37 ′ are not connected to other terminal 37 . By changing the combination of the nine terminals 37 ′, different aspects of the I/O port can be tested.
[0029] Referring to FIG. 7 , three connectors 51 , 52 , and 53 are the same type connector as the second connector 31 ′. Each of the terminals 37 ′ of second connector 31 ′ is connected to corresponding terminal of the connectors 51 , 52 , and 53 at the same time. The second connector 31 ′ is connected to a control I/O port (not shown), and each of the connectors 51 , 52 , and 53 is connected to a testing I/O port (not shown). Pins of the testing I/O ports connected to the connectors 51 , 52 , and 53 are controlled by changing signals on pins of the control I/O port connected to the second connector 31 ′. It is convenient to testing a plurality of testing I/O port at the same time.
[0030] It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of preferred embodiments, together with details of the structures and functions of the preferred embodiments, the 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 invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
|
A testing tool for testing an I/O port includes a cable and a testing card. The cable includes a port formed at one end thereof configured for being connected to the I/O port, and a first connector formed at an opposite end thereof. The testing card includes two testing circuits and a second connector connected to the first connector. The second connector includes a slider shiftable between a first position where the second connector and a testing circuit are interconnected, and a second position where the second connector and the other testing circuit are interconnected.
| 6
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.