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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and is a continuation of U.S. patent application Ser. No. 12/910,104, entitled “Bis-Azo Colorants for Use as Bluing Agents,” which was filed on Oct. 22, 2010, and is entirely incorporated by reference herein.
TECHNICAL FIELD
This invention relates to bis-azo colorants for use as bluing agents, laundry care compositions comprising bis-azo colorants that may serve as bluing agents, processes for making such bluing agents and laundry care compositions and methods of using the same. The bluing agents are generally comprised of at least two components: at least one chromophore component and at least one polymeric component. These bluing agents are advantageous in providing a whitening effect to fabrics, while not building up over time and causing undesirable blue discoloration to the treated fabrics.
BACKGROUND
As textile substrates age, their color tends to fade or yellow due to exposure to light, air, soil, and natural degradation of the fibers that comprise the substrates. Thus, the purpose of bluing agents is generally to visually brighten these textile substrates and counteract the fading and yellowing of the substrates. Typically, bluing agents may be found in laundry detergents, fabric softeners, or rinse aids and are therefore applied to textile substrates during the laundering process. However, it is important that bluing agents function to brighten treated textile substrates without causing undesirable staining of the textile substrates. Cellulosic substrates, in particular, tend to exhibit a yellow hue after exposure to light, air, and/or soiling. This yellowness is often difficult to reverse by normal laundering procedures. As a result, there exists a need for improved bluing agents which are capable of eliminating the yellowness exhibited by ageing cellulosic substrates. By utilizing such improved bluing agents, the life of the textile substrates, such as clothing articles, table linens, etc., may be extended. Unfortunately, current bluing agents either do not provide a hueing benefit after a single treatment cycle and/or they build up to an undesirable level, thus overhueing the treated situs over multiple treatment cycles.
The present invention offers advantages over previous efforts in this area, as this invention takes advantage of compounds having a non-sulfonic acid substituent in the terminal phenyl ring of the bis-azo structure. Sulfonic acid groups are known to promote the deposition and staining of acid dyes on cellulosic fabrics. These groups are also essential for the solubility and compatibility of the dyes in laundry formulations. While it is necessary that bluing agents deposit from wash water, it is undesirable that they stain the fabric by inadvertent contact or by building up over time, i.e. overhueing. Applicants recognized that modification or replacement of the sulfonic acid group at the phenyl terminal end of the bis-azo with a nonionic solubilizing group allows for good deposition of the bis-azo but attenuates its staining and overhueing tendencies and still allows the bluing agent to be compatible in laundry formulations. In short, Applicants recognized the source of the current hueing deficiencies and herein provide the solution to such problem. The hueing compounds disclosed herein also absorb light at a wavelength appropriate to neutralize the yellowness of cellulosic substrates. These compounds function ideally as bluing agents for cellulosic substrates and may be incorporated into laundry care compositions for use by consumers.
SUMMARY OF INVENTION
This invention relates to laundry care compositions comprising bis-azo colorants that may serve as bluing agents, processes for making such laundry care compositions and methods of using the same. The bluing agents are generally comprised of at least two components: at least one chromophore component and at least one polymeric component. These bluing agents are advantageous in providing a whitening effect to fabrics, while not building up over time and causing undesirable blue discoloration to the treated fabrics.
In one aspect of the invention, the bluing agent comprises (a) at least one chromophore component that comprises a bis-azo colorant, and (b) at least one polymeric component or substituted sulfonamide component; wherein the bluing agent has the following structure:
wherein:
R 1 and R 2 are independently H, alkyl, alkoxy, alkyleneoxy, alkyl capped alkyleneoxy, polyalkyleneoxy, alkyl capped polyalkyleneoxy, urea, or amido; R 3 is an aryl group substituent that may be a substituted phenyl or napthyl moiety; X is a substituted oxygen, a substituted or unsubstituted amino, or a substituted or unsubstituted sulfonamide group wherein the substituents are selected from the group consisting of alkyl, alkyleneoxy, polyalkyleneoxy, or phenyl moieties wherein the phenyl group may be further substituted with alkyl, alkyleneoxy or polyalkyleneoxy moieties.
In another aspect of the invention, the bluing agent has the following structure:
wherein:
R 1 and R 2 are independently H, alkyl, alkoxy, alkyleneoxy, alkyl capped alkyleneoxy, polyalkyleneoxy, alkyl capped polyalkyleneoxy, or amido; W is a substituted amino moiety; U is a hydrogen, an amino group or an amino group substituted with an acyl group; Y is a hydrogen or a sulfonic acid moiety; and Z is a sulfonic acid moiety or an amino group substituted with a phenyl group.
In yet another aspect of the invention, R 1 is alkoxy and R 2 is alkyl.
DETAILED DESCRIPTION
As used herein, the term “alkoxy” is intended to include C 1 -C 6 alkoxy and alkoxy derivatives of polyols having repeating units such as butylene oxide, glycidol oxide, ethylene oxide or propylene oxide.
As used herein, the terms “alkyl” and “alkyl capped” are intended to include C 1 -C 6 alkyl groups.
The terms “ethylene oxide,” “propylene oxide” and “butylene oxide” shown herein by their typical designation of “EO,” “PO” and “BO,” respectively.
As used herein, the term “laundry care composition” includes, unless otherwise indicated, granular, powder, liquid, gel, paste, unit dose bar form and/or flake type washing agents and/or fabric treatment compositions.
As used herein, the term “fabric treatment composition” includes, unless otherwise indicated, fabric softening compositions, fabric enhancing compositions, fabric freshening compositions and combinations there of. Such compositions may be, but need not be rinse added compositions.
As used herein, “cellulosic substrates” are intended to include any substrate which comprises at least a majority by weight of cellulose. Cellulose may be found in wood, cotton, linen, jute, and hemp. Cellulosic substrates may be in the form of powders, fibers, pulp and articles formed from powders, fibers and pulp. Cellulosic fibers, include, without limitation, cotton, rayon (regenerated cellulose), acetate (cellulose acetate), triacetate (cellulose triacetate), and mixtures thereof. Articles formed from cellulosic fibers include textile articles such as fabrics. Articles formed from pulp include paper.
As used herein, the articles including “the”, “a” and “an” when used in a claim, are understood to mean one or more of what is claimed or described.
As used herein, the terms “include”, “includes” and “including” are meant to be non-limiting.
The test methods disclosed in the Test Methods Section of the present application should be used to determine the respective values of the parameters of Applicants' inventions.
Unless otherwise noted, all component or composition levels are in reference to the active portion of that component or composition, and are exclusive of impurities, for example, residual solvents or by-products, which may be present in commercially available sources of such components or compositions.
All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.
It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
All documents cited are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.
Suitable Bluing Agents
The bluing agents employed in the present laundry care compositions may be dyes, pigments, or polymeric colorants comprising a chromophore constituent and a polymeric constituent. The chromophore constituent is characterized in that it absorbs light in the wavelength range of blue, red, violet, purple, or combinations thereof upon exposure to light. In one aspect, the chromophore constituent exhibits an absorbance spectrum maximum from about 520 nanometers to about 640 nanometers in water and/or methanol, and in another aspect, from about 560 nanometers to about 610 nanometers in water and/or methanol.
Examples of suitable polymeric constituents include polyoxyalkylene chains having multiple repeating units. In one aspect, the polymeric constituents include polyoxyalkylene chains having from 2 to about 30 repeating units, from 2 to about 20 repeating units, from 2 to about 10 repeating units or even from about 3 or 4 to about 6 repeating units. Non-limiting examples of polyoxyalkylene chains include ethylene oxide, propylene oxide, glycidol oxide, butylene oxide and mixtures thereof.
In one aspect, the bluing agent employed in the present laundry care compositions may be characterized by the following general Structure (I):
wherein:
R 1 and R 2 are independently H, alkyl, alkoxy, alkyleneoxy, alkyl capped alkyleneoxy, polyalkyleneoxy, alkyl capped polyalkyleneoxy, urea, or amido;
R 3 is an aryl group substituent that may be a substituted phenyl or napthyl moiety;
X is a substituted oxygen, a substituted or unsubstituted amino, or a substituted or unsubstituted sulfonamide group wherein the substituents are selected from the group consisting of alkyl, alkyleneoxy, polyalkyleneoxy, or phenyl moieties wherein the phenyl group may be further substituted with alkyl, alkyleneoxy or polyalkyleneoxy moieties.
In another aspect, suitable bluing agents may be characterized by the following general Structure (II):
wherein:
R 1 and R 2 are independently H, alkyl, alkoxy, alkyleneoxy, alkyl capped alkyleneoxy, polyalkyleneoxy, alkyl capped polyalkyleneoxy, or amido;
W is a substituted amino moiety;
X is a hydrogen, an amino group or an amino group substituted with an acyl group;
Y is a hydrogen or a sulfonic acid moiety; and
Z is a sulfonic acid moiety or an amino group substituted with a phenyl group.
In further aspects, suitable bluing agents may be characterized by the following general Structure (III):
wherein:
R 1 is alkoxy;
R 2 is alkyl;
W is a substituted amino moiety;
X is a hydrogen, an amino group or an amino group substituted with an acyl group;
Y is a hydrogen or a sulfonic acid moiety; and
Z is a sulfonic acid moiety or an amino group substituted with a phenyl group.
In one aspect of the invention, suitable bluing agents include, but are not limited to the following structures:
A suitable synthesis route for certain bis-azo colorants disclosed herein is shown below:
Wherein:
R is selected from the group consisting of alkyl, polyalkyleneoxy, phenyl and substituted phenyl, and R′ is selected from the group consisting of hydrogen, alkyl, or alkoxy.
Other certain bis-azo colorants disclosed herein may be prepared in a similar manner by substituting 2-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]-5-methylbenzenamine for either 2-methoxy-5-methylbenzenamine or 2,5-dimethoxybenzenamine in the synthesis scheme above.
The base utilized in the first step of the reaction may be selected from sodium carbonate, sodium acetate, sodium hydroxide, or other cationic salts of these respective bases, and tertiary amines.
Acid hydrolysis may be carried out utilizing a strong acid such as hydrochloric acid or sulfuric acid.
Alternatively, the bis-azo colorants disclosed herein may be made according to various procedures known in the art and/or in accordance with the examples of the present invention. For example, coupling may be carried out using polyalkyleneoxy substituted aniline compounds derived by known procedures from starting materials such as 4-methyoxy-2-nitrophenol or 4-methyl-2-nitrophenol, both of which are available from VWR International, LLC (West Chester, Pa., USA).
Laundry Care Compositions
The bluing agents described in the present specification may be incorporated into laundry care compositions including but not limited to laundry detergents and fabric care compositions. The laundry care compositions including laundry detergents may be in solid or liquid form, including a gel form. Such compositions may comprise one or more of said bluing agents and a laundry care ingredient. The bluing agents may be added to substrates using a variety of application techniques. For instance, for application to cellulose-containing textile substrates, the bluing agent may be included as a component of a laundry detergent. Thus, application to a cellulose-containing textile substrate actually occurs when a consumer adds laundry detergent to a washing machine. The bluing agent may be present in the laundry detergent composition in an amount from about 0.0001% to about 10% by weight of the composition, from about 0.0001% to about 5% by weight of the composition, and even from about 0.0001% to about 1% by weight of the composition.
The laundry detergent composition typically comprises a surfactant in an amount sufficient to provide desired cleaning properties. In one aspect, the laundry detergent composition may comprise, based on total laundry detergent composition weight, from about 5% to about 90% of the surfactant, from about 5% to about 70% of the surfactant, or even from about 5% to about 40% of the surfactant. The surfactant may comprise anionic, nonionic, cationic, zwitterionic and/or amphoteric surfactants. In one aspect, the detergent composition comprises anionic surfactant, nonionic surfactant, or mixtures thereof.
Fabric care compositions are typically added in the rinse cycle, which is after the detergent solution has been used and replaced with the rinsing solution in typical laundering processes. The fabric care compositions disclosed herein may be comprise a rinse added fabric softening active and a suitable bluing agent as disclosed in the present specification. The fabric care composition may comprise, based on total fabric care composition weight, from about 1% to about 90%, or from about 5% to about 50% fabric softening active. The bluing agent may be present in the fabric care composition in an amount from about 0.5 ppb to about 50 ppm, or from about 0.5 ppm to about 30 ppm.
Suitable Laundry Care Ingredients
While not essential for the purposes of the present invention, the non-limiting list of laundry care ingredients illustrated hereinafter are suitable for use in the laundry care compositions and may be desirably incorporated in certain aspects of the invention, for example to assist or enhance performance, for treatment of the substrate to be cleaned, or to modify the aesthetics of the composition as is the case with perfumes, colorants, dyes or the like. It is understood that such ingredients are in addition to the components that were previously listed for any particular aspect. The total amount of such adjuncts may range, once the amount of dye is taken into consideration from about 90% to about 99.99999995% by weight of the laundry care composition.
The precise nature of these additional components, and levels of incorporation thereof, will depend on the physical form of the composition and the nature of the operation for which it is to be used. Suitable laundry care ingredients include, but are not limited to, fabric softening actives, polymers, for example cationic polymers, surfactants, builders, chelating agents, dye transfer inhibiting agents, dispersants, enzymes, and enzyme stabilizers, catalytic materials, bleach activators, polymeric dispersing agents, clay soil removal/anti-redeposition agents, brighteners, suds suppressors, dyes, additional perfume and perfume delivery systems, structure elasticizing agents, fabric softeners, carriers, hydrotropes, processing aids and/or pigments. In addition to the disclosure below, suitable examples of such other adjuncts and levels of use are found in U.S. Pat. Nos. 5,576,282, 6,306,812 B1 and 6,326,348 B1 that are incorporated by reference.
As stated, the laundry care ingredients are not essential to Applicants' laundry care compositions. Thus, certain aspects of Applicants' compositions do not contain one or more of the following adjuncts materials: fabric softening actives, bleach activators, surfactants, builders, chelating agents, dye transfer inhibiting agents, dispersants, enzymes, and enzyme stabilizers, catalytic metal complexes, polymeric dispersing agents, clay and soil removal/anti-redeposition agents, brighteners, suds suppressors, dyes, additional perfumes and perfume delivery systems, structure elasticizing agents, fabric softeners, carriers, hydrotropes, processing aids and/or pigments. However, when one or more adjuncts are present, such one or more adjuncts may be present as detailed below:
Surfactants
Suitable anionic surfactants useful herein can comprise any of the conventional anionic surfactant types typically used in liquid detergent products. These include the alkyl benzene sulfonic acids and their salts as well as alkoxylated or non-alkoxylated alkyl sulfate materials.
Exemplary anionic surfactants are the alkali metal salts of C 10 -C 16 alkyl benzene sulfonic acids, or C 11 -C 14 alkyl benzene sulfonic acids. In one aspect, the alkyl group is linear and such linear alkyl benzene sulfonates are known as “LAS”. Alkyl benzene sulfonates, and particularly LAS, are well known in the art. Such surfactants and their preparation are described for example in U.S. Pat. Nos. 2,220,099 and 2,477,383. Especially useful are the sodium and potassium linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 11 to 14. Sodium C 11 -C 14 , e.g., C 12 , LAS is a specific example of such surfactants.
Another exemplary type of anionic surfactant comprises ethoxylated alkyl sulfate surfactants. Such materials, also known as alkyl ether sulfates or alkyl polyethoxylate sulfates, are those which correspond to the formula: R′—O—(C 2 H 4 O) n —SO 3 M wherein R′ is a C 8 -C 20 alkyl group, n is from about 1 to 20, and M is a salt-forming cation. In one aspect, R′ is C 10 -C 18 alkyl, n is from about 1 to 15, and M is sodium, potassium, ammonium, alkylammonium, or alkanolammonium. In one aspect, R′ is a C 12 -C 16 , n is from about 1 to 6 and M is sodium.
The alkyl ether sulfates will generally be used in the form of mixtures comprising varying R′ chain lengths and varying degrees of ethoxylation. Frequently such mixtures will inevitably also contain some non-ethoxylated alkyl sulfate materials, i.e., surfactants of the above ethoxylated alkyl sulfate formula wherein n=0. Non-ethoxylated alkyl sulfates may also be added separately to the compositions of this invention and used as or in any anionic surfactant component which may be present. Specific examples of non-alkoxylated, e.g., non-ethoxylated, alkyl ether sulfate surfactants are those produced by the sulfation of higher C 8 -C 20 fatty alcohols. Conventional primary alkyl sulfate surfactants have the general formula: ROSO 3 -M + wherein R is typically a linear C 8 -C 20 hydrocarbyl group, which may be straight chain or branched chain, and M is a water-solubilizing cation. In one aspect, R is a C 10 -C 15 alkyl, and M is alkali metal, more specifically R is C 12 -C 14 and M is sodium.
Specific, non-limiting examples of anionic surfactants useful herein include: a) C 11 -C 18 alkyl benzene sulfonates (LAS); b) C 10 -C 20 primary, branched-chain and random alkyl sulfates (AS); c) C 10 -C 18 secondary (2,3) alkyl sulfates having formulae (I) and (II): wherein M in formulae (I) and (II) is hydrogen or a cation which provides charge neutrality, and all M units, whether associated with a surfactant or adjunct ingredient, can either be a hydrogen atom or a cation depending upon the form isolated by the artisan or the relative pH of the system wherein the compound is used, with non-limiting examples of suitable cations including sodium, potassium, ammonium, and mixtures thereof, and x is an integer of at least about 7, or at least about 9, and y is an integer of at least 8, or at least about 9; d) C 10 -C 18 alkyl alkoxy sulfates (AE x S) wherein x is from 1-30; e) C 10 -C 18 alkyl alkoxy carboxylates in one aspect, comprising 1-5 ethoxy units; f) mid-chain branched alkyl sulfates as discussed in U.S. Pat. Nos. 6,020,303 and 6,060,443; g) mid-chain branched alkyl alkoxy sulfates as discussed in U.S. Pat. Nos. 6,008,181 and 6,020,303; h) modified alkylbenzene sulfonate (MLAS) as discussed in WO 99/05243, WO 99/05242, WO 99/05244, WO 99/05082, WO 99/05084, WO 99/05241, WO 99/07656, WO 00/23549, and WO 00/23548; i) methyl ester sulfonate (MES); and j) alpha-olefin sulfonate (AOS).
Suitable nonionic surfactants useful herein can comprise any of the conventional nonionic surfactant types typically used in liquid detergent products. These include alkoxylated fatty alcohols and amine oxide surfactants. In one aspect, for use in the liquid detergent products herein are those nonionic surfactants which are normally liquid.
Suitable nonionic surfactants for use herein include the alcohol alkoxylate nonionic surfactants. Alcohol alkoxylates are materials which correspond to the general formula: R 1 (C m H 2m O) n OH wherein R 1 is a C 8 -C 16 alkyl group, m is from 2 to 4, and n ranges from about 2 to 12. In one aspect, R 1 is an alkyl group, which may be primary or secondary, that comprises from about 9 to 15 carbon atoms, or from about 10 to 14 carbon atoms. In one aspect, the alkoxylated fatty alcohols will also be ethoxylated materials that contain from about 2 to 12 ethylene oxide moieties per molecule, or from about 3 to 10 ethylene oxide moieties per molecule.
The alkoxylated fatty alcohol materials useful in the liquid detergent compositions herein will frequently have a hydrophilic-lipophilic balance (HLB) which ranges from about 3 to 17 from about 6 to 15, or from about 8 to 15. Alkoxylated fatty alcohol nonionic surfactants have been marketed under the tradenames Neodol and Dobanol by the Shell Chemical Company.
Another suitable type of nonionic surfactant useful herein comprises the amine oxide surfactants. Amine oxides are materials which are often referred to in the art as “semi-polar” nonionics. Amine oxides have the formula: R(EO) x (PO) y (BO) z N(O)(CH 2 R′) 2 .qH 2 O. In this formula, R is a relatively long-chain hydrocarbyl moiety which can be saturated or unsaturated, linear or branched, and can contain from 8 to 20, 10 to 16 carbon atoms, or is a C 12 -C 16 primary alkyl. R′ is a short-chain moiety, in one aspect R′ may be selected from hydrogen, methyl and —CH 2 OH. When x+y+z is different from 0, EO is ethyleneoxy, PO is propyleneneoxy and BO is butyleneoxy. Amine oxide surfactants are illustrated by C 12-14 alkyldimethyl amine oxide.
Non-limiting examples of nonionic surfactants include: a) C 12 -C 18 alkyl ethoxylates, such as, NEODOL® nonionic surfactants from Shell; b) C 6 -C 12 alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units; c) C 12 -C 18 alcohol and C 6 -C 12 alkyl phenol condensates with ethylene oxide/propylene oxide block polymers such as Pluronic® from BASF; d) C 14 -C 22 mid-chain branched alcohols, BA, as discussed in U.S. Pat. No. 6,150,322; e) C 14 -C 22 mid-chain branched alkyl alkoxylates, BAE x , wherein x if from 1-30, as discussed in U.S. Pat. Nos. 6,153,577, 6,020,303 and 6,093,856; f) Alkylpolysaccharides as discussed in U.S. Pat. No. 4,565,647 to Llenado, issued Jan. 26, 1986; specifically alkylpolyglycosides as discussed in U.S. Pat. Nos. 4,483,780 and 4,483,779; g) Polyhydroxy fatty acid amides as discussed in U.S. Pat. No. 5,332,528, WO 92/06162, WO 93/19146, WO 93/19038, and WO 94/09099; and h) ether capped poly(oxyalkylated) alcohol surfactants as discussed in U.S. Pat. No. 6,482,994 and WO 01/42408.
In the laundry detergent compositions herein, the detersive surfactant component may comprise combinations of anionic and nonionic surfactant materials. When this is the case, the weight ratio of anionic to nonionic will typically range from 10:90 to 90:10, more typically from 30:70 to 70:30.
Cationic surfactants are well known in the art and non-limiting examples of these include quaternary ammonium surfactants, which can have up to 26 carbon atoms. Additional examples include a) alkoxylate quaternary ammonium (AQA) surfactants as discussed in U.S. Pat. No. 6,136,769; b) dimethyl hydroxyethyl quaternary ammonium as discussed in U.S. Pat. No. 6,004,922; c) polyamine cationic surfactants as discussed in WO 98/35002, WO 98/35003, WO 98/35004, WO 98/35005, and WO 98/35006; d) cationic ester surfactants as discussed in U.S. Pat. Nos. 4,228,042, 4,239,660 4,260,529 and 6,022,844; and e) amino surfactants as discussed in U.S. Pat. No. 6,221,825 and WO 00/47708, specifically amido propyldimethyl amine (APA).
Non-limiting examples of zwitterionic surfactants include derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. See U.S. Pat. No. 3,929,678 to Laughlin et al., issued Dec. 30, 1975 at column 19, line 38 through column 22, line 48, for examples of zwitterionic surfactants; betaine, including alkyl dimethyl betaine and cocodimethyl amidopropyl betaine, C 8 to C 18 (in one aspect C 12 to C 18 ) amine oxides and sulfo and hydroxy betaines, such as N-alkyl-N,N-dimethylammino-1-propane sulfonate where the alkyl group can be C 8 to C 18 , or C 10 to C 14 .
Non-limiting examples of ampholytic surfactants include aliphatic derivatives of secondary or tertiary amines, or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical can be straight- or branched-chain. One of the aliphatic substituents comprises at least about 8 carbon atoms, typically from about 8 to about 18 carbon atoms, and at least one comprises an anionic water-solubilizing group, e.g. carboxy, sulfonate, sulfate. See U.S. Pat. No. 3,929,678 to Laughlin et al., issued Dec. 30, 1975 at column 19, lines 18-35, for examples of ampholytic surfactants.
Aqueous, Non-Surface Active Liquid Carrier
As noted, the laundry care compositions may be in the form of a solid, either in tablet or particulate form, including, but not limited to particles, flakes, sheets, or the like, or the compositions may be in the form of a liquid. The liquid detergent compositions may comprise an aqueous, non-surface active liquid carrier. Generally, the amount of the aqueous, non-surface active liquid carrier employed in the compositions herein will be effective to solubilize, suspend or disperse the composition components. For example, the liquid detergent compositions may comprise, based on total liquid detergent composition weight, from about 5% to about 90%, from about 10% to about 70%, or from about 20% to about 70% of the aqueous, non-surface active liquid carrier.
The most cost effective type of aqueous, non-surface active liquid carrier is typically water. Accordingly, the aqueous, non-surface active liquid carrier component will generally be mostly, if not completely, comprised of water. While other types of water-miscible liquids, such alkanols, diols, other polyols, ethers, amines, and the like, have been conventionally been added to liquid detergent compositions as co-solvents or stabilizers, for purposes of the present invention, the utilization of such water-miscible liquids typically is minimized to hold down composition cost. Accordingly, the aqueous liquid carrier component of the liquid detergent products herein will generally comprise water present in concentrations ranging from about 5% to about 90%, or from about 5% to about 70%, by weight of the liquid detergent composition.
Bleaching Agents
Bleaching Agents—The cleaning compositions of the present invention may comprise one or more bleaching agents. Suitable bleaching agents other than bleaching catalysts include photobleaches, bleach activators, hydrogen peroxide, sources of hydrogen peroxide, pre-formed 25 peracids and mixtures thereof. In general, when a bleaching agent is used, the compositions of the present invention may comprise from about 0.1% to about 50% or even from about 0.1% to about 25% bleaching agent by weight of the subject cleaning composition. Examples of suitable bleaching agents include:
(1) photobleaches for example sulfonated zinc phthalocyanine;
(2) preformed peracids: Suitable preformed peracids include, but are not limited to, compounds selected from the group consisting of percarboxylic acids and salts, percarbonic acids and salts, perimidic acids and salts, peroxymonosulfuric acids and salts, for example, Oxzone®, and mixtures thereof. Suitable percarboxylic acids include hydrophobic and hydrophilic peracids having the formula R—(C═O)O—O-M wherein R is an alkyl group, optionally branched, having, when the peracid is hydrophobic, from 6 to 14 carbon atoms, or from 8 to 12 carbon atoms and, when the peracid is hydrophilic, less than 6 carbon atoms or even less than 4 carbon atoms; and M is a counterion, for example, sodium, potassium or hydrogen;
(3) sources of hydrogen peroxide, for example, inorganic perhydrate salts, including alkali metal salts such as sodium salts of perborate (usually mono- or tetra-hydrate), percarbonate, persulphate, perphosphate, persilicate salts and mixtures thereof. In one aspect of the invention the inorganic perhydrate salts are selected from the group consisting of sodium salts of perborate, percarbonate and mixtures thereof. When employed, inorganic perhydrate salts are typically present in amounts of from 0.05 to 40 wt %, or 1 to 30 wt % of the overall composition and are typically incorporated into such compositions as a crystalline solid that may be coated. Suitable coatings include, inorganic salts such as alkali metal silicate, carbonate or borate salts or mixtures thereof, or organic materials such as water-soluble or dispersible polymers, waxes, oils or fatty soaps; and
(4) bleach activators having R—(C═O)-L wherein R is an alkyl group, optionally branched, having, when the bleach activator is hydrophobic, from 6 to 14 carbon atoms, or from 8 to 12 carbon atoms and, when the bleach activator is hydrophilic, less than 6 carbon atoms or even less than 4 carbon atoms; and L is leaving group. Examples of suitable leaving groups are benzoic acid and derivatives thereof—especially benzene sulphonate. Suitable bleach activators include dodecanoyl oxybenzene sulphonate, decanoyl oxybenzene sulphonate, decanoyl oxybenzoic acid or salts thereof, 3,5,5-trimethyl hexanoyloxybenzene sulphonate, tetraacetyl ethylene diamine (TAED) and nonanoyloxybenzene sulphonate (NOBS). Suitable bleach activators are also disclosed in WO 98/17767. While any suitable bleach activator may be employed, in one aspect of the invention the subject cleaning composition may comprise NOBS, TAED or mixtures thereof.
When present, the peracid and/or bleach activator is generally present in the composition in an amount of from about 0.1 to about 60 wt %, from about 0.5 to about 40 wt % or even from about 0.6 to about 10 wt % based on the composition. One or more hydrophobic peracids or precursors thereof may be used in combination with one or more hydrophilic peracid or precursor thereof.
The amounts of hydrogen peroxide source and peracid or bleach activator may be selected such that the molar ratio of available oxygen (from the peroxide source) to peracid is from 1:1 to 35:1, or even 2:1 to 10:1.
Bleach Boosting Compounds—The compositions herein may comprise one or more bleach boosting compounds. Bleach boosting compounds provide increased bleaching effectiveness in lower temperature applications. The bleach boosters act in conjunction with conventional peroxygen bleaching sources to provide increased bleaching effectiveness. This is normally accomplished through in situ formation of an active oxygen transfer agent such as a dioxirane, an oxaziridine, or an oxaziridinium. Alternatively, preformed dioxiranes, oxaziridines and oxaziridiniums may be used.
Among suitable bleach boosting compounds for use in accordance with the present invention are cationic imines, zwitterionic imines, anionic imines and/or polyionic imines having a net charge of from about +3 to about −3, and mixtures thereof. These imine bleach boosting compounds of the present invention include those of the general structure:
where R 1 -R 4 may be a hydrogen or an unsubstituted or substituted radical selected from the group consisting of phenyl, aryl, heterocyclic ring, alkyl and cycloalkyl radicals.
Suitable bleach boosting compounds include zwitterionic bleach boosters zwitterionic bleach boosters, which are described in U.S. Pat. Nos. 5,576,282 and 5,718,614. Other bleach boosting compounds include cationic bleach boosters described in U.S. Pat. Nos. 5,360,569; 5,442,066; 5,478,357; 5,370,826; 5,482,515; 5,550,256; and WO 95/13351, WO 95/13352, and WO 95/13353.
Peroxygen sources are well-known in the art and the peroxygen source employed in the present invention may comprise any of these well known sources, including peroxygen compounds as well as compounds, which under consumer use conditions, provide an effective amount of peroxygen in situ. The peroxygen source may include a hydrogen peroxide source, the in situ formation of a peracid anion through the reaction of a hydrogen peroxide source and a bleach activator, preformed peracid compounds or mixtures of suitable peroxygen sources. Of course, one of ordinary skill in the art will recognize that other sources of peroxygen may be employed without departing from the scope of the invention. The bleach boosting compounds, when present, are typically employed in conjunction with a peroxygen source in the bleaching systems of the present invention.
Enzyme Bleaching—Enzymatic systems may be used as bleaching agents. The hydrogen peroxide may also be present by adding an enzymatic system (i.e. an enzyme and a substrate therefore) which is capable of generating hydrogen peroxide at the beginning or during the washing and/or rinsing process. Such enzymatic systems are disclosed in EP Patent Application 91202655.6 filed Oct. 9, 1991.
The present invention compositions and methods may utilize alternative bleach systems such as ozone, chlorine dioxide and the like. Bleaching with ozone may be accomplished by introducing ozone-containing gas having ozone content from about 20 to about 300 g/m 3 into the solution that is to contact the fabrics. The gas:liquid ratio in the solution should be maintained from about 1:2.5 to about 1:6. U.S. Pat. No. 5,346,588 describes a process for the utilization of ozone as an alternative to conventional bleach systems and is herein incorporated by reference.
In one aspect, the fabric softening active (“FSA”) is a quaternary ammonium compound suitable for softening fabric in a rinse step. In one aspect, the FSA is formed from a reaction product of a fatty acid and an aminoalcohol obtaining mixtures of mono-, di-, and, in one aspect, triester compounds. In another aspect, the FSA comprises one or more softener quaternary ammonium compounds such, but not limited to, as a monoalkyquaternary ammonium compound, a diamido quaternary compound and a diester quaternary ammonium compound, or a combination thereof.
In one aspect of the invention, the FSA comprises a diester quaternary ammonium (hereinafter “DQA”) compound composition. In certain aspects of the present invention, the DQA compounds compositions also encompasses a description of diamido FSAs and FSAs with mixed amido and ester linkages as well as the aforementioned diester linkages, all herein referred to as DQA.
A first type of DQA (“DQA (1)”) suitable as a FSA in the present CFSC includes a compound comprising the formula:
{R 4-m —N + —[(CH 2 ) n —Y—R 1 ] m }X −
wherein each R substituent is either hydrogen, a short chain C 1 -C 6 , for example C 1 -C 3 alkyl or hydroxyalkyl group, e.g., methyl, ethyl, propyl, hydroxyethyl, and the like, poly (C 2-3 alkoxy), for example. polyethoxy, group, benzyl, or mixtures thereof; each m is 2 or 3; each n is from 1 to about 4, or 2; each Y is —O—(O)C—, —C(O)—O—, —NR—C(O)—, or —C(O)—NR— and it is acceptable for each Y to be the same or different; the sum of carbons in each R 1 , plus one when Y is —O—(O)C— or —NR—C(O)—, is C 12 -C 22 , or C 14 -C 20 , with each R 1 being a hydrocarbyl, or substituted hydrocarbyl group; it is acceptable for R 1 to be unsaturated or saturated and branched or linear and in one aspect it is linear; it is acceptable for each R 1 to be the same or different and typically these are the same; and X − can be any softener-compatible anion, suitable anions include, chloride, bromide, methylsulfate, ethylsulfate, sulfate, phosphate, and nitrate, in one aspect the anions are chloride or methyl sulfate. Suitable DQA compounds are typically made by reacting alkanolamines such as MDEA (methyldiethanolamine) and TEA (triethanolamine) with fatty acids. Some materials that typically result from such reactions include N,N-di(acyl-oxyethyl)-N,N-dimethylammonium chloride or N,N-di(acyl-oxyethyl)-N,N-methylhydroxyethylammonium methylsulfate wherein the acyl group is derived from animal fats, unsaturated, and polyunsaturated, fatty acids, e.g., tallow, hardended tallow, oleic acid, and/or partially hydrogenated fatty acids, derived from vegetable oils and/or partially hydrogenated vegetable oils, such as, canola oil, safflower oil, peanut oil, sunflower oil, corn oil, soybean oil, tall oil, rice bran oil, palm oil, etc.
Non-limiting examples of suitable fatty acids are listed in U.S. Pat. No. 5,759,990 at column 4, lines 45-66. In one aspect, the FSA comprises other actives in addition to DQA (1) or DQA. In yet another aspect, the FSA comprises only DQA (1) or DQA and is free or essentially free of any other quaternary ammonium compounds or other actives. In yet another aspect, the FSA comprises the precursor amine that is used to produce the DQA.
In another aspect of the invention, the FSA comprises a compound, identified as DTTMAC comprising the formula:
[R 4-m —N (+) —R 1 m ]A −
wherein each m is 2 or 3, each R 1 is a C 6 -C 22 , or C 14 -C 20 , but no more than one being less than about C 12 and then the other is at least about 16, hydrocarbyl, or substituted hydrocarbyl substituent, for example, C 10 -C 20 alkyl or alkenyl (unsaturated alkyl, including polyunsaturated alkyl, also referred to sometimes as “alkylene”), in one aspect C 12 -C 18 alkyl or alkenyl, and branch or unbranched. In one aspect, the Iodine Value (IV) of the FSA is from about 1 to 70; each R is H or a short chain C 1 -C 6 , or C 1 -C 3 alkyl or hydroxyalkyl group, e.g., methyl, ethyl, propyl, hydroxyethyl, and the like, benzyl, or (R 2 O) 2-4 H where each R 2 is a C 1-6 alkylene group; and A − is a softener compatible anion, suitable anions include chloride, bromide, methylsulfate, ethylsulfate, sulfate, phosphate, or nitrate; in one aspect the anions are chloride or methyl sulfate.
Examples of these FSAs include dialkydimethylammonium salts and dialkylenedimethylammonium salts such as ditallowedimethylammonium and ditallowedimethylammonium methylsulfate. Examples of commercially available dialkylenedimethylammonium salts usable in the present invention are di-hydrogenated tallow dimethyl ammonium chloride and ditallowedimethyl ammonium chloride available from Degussa under the trade names Adogen® 442 and Adogen® 470 respectively. In one aspect, the FSA comprises other actives in addition to DTTMAC. In yet another aspect, the FSA comprises only compounds of the DTTMAC and is free or essentially free of any other quaternary ammonium compounds or other actives.
In one aspect, the FSA comprises an FSA described in U.S. Pat. Pub. No. 2004/0204337 A1, published Oct. 14, 2004 to Corona et al., from paragraphs 30-79. In another aspect, the FSA is one described in U.S. Pat. Pub. No. 2004/0229769 A1, published Nov. 18, 2005, to Smith et al., on paragraphs 26-31; or U.S. Pat. No. 6,494,920, at column 1, line 51 et seq. detailing an “esterquat” or a quaternized fatty acid triethanolamine ester salt.
In one aspect, the FSA is chosen from at least one of the following: ditallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, ditallow dimethyl ammonium chloride, ditallowoyloxyethyl dimethyl ammonium methyl sulfate, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, or combinations thereof.
In one aspect, the FSA may also include amide containing compound compositions. Examples of diamide comprising compounds may include but not limited to methyl-bis(tallowamidoethyl)-2-hydroxyethylammonium methyl sulfate (available from Degussa under the trade names Varisoft 110 and Varisoft 222). An example of an amide-ester containing compound is N-[3-(stearoylamino)propyl]-N-[2-(stearoyloxy)ethoxy)ethyl)]-N-methylamine.
Another aspect of the invention provides for a rinse added fabric softening composition further comprising a cationic starch. Cationic starches are disclosed in US 2004/0204337 A1. In one aspect, the rinse added fabric softening composition comprises from about 0.1% to about 7% of cationic starch by weight of the fabric softening composition. In one aspect, the cationic starch is HCP401 from National Starch.
Builders—The compositions of the present invention can comprise one or more detergent builders or builder systems. When present, the compositions will typically comprise at least about 1% builder, or from about 5% or 10% to about 80%, 50%, or even 30% by weight, of said builder. Builders include, but are not limited to, the alkali metal, ammonium and alkanolammonium salts of polyphosphates, alkali metal silicates, alkaline earth and alkali metal carbonates, aluminosilicate builders polycarboxylate compounds. ether hydroxypolycarboxylates, copolymers of maleic anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxybenzene-2,4,6-trisulphonic acid, and carboxymethyl-oxysuccinic acid, the various alkali metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof. Chelating Agents—The compositions herein may also optionally contain one or more copper, iron and/or manganese chelating agents. If utilized, chelating agents will generally comprise from about 0.1% by weight of the compositions herein to about 15%, or even from about 3.0% to about 15% by weight of the compositions herein. Dye Transfer Inhibiting Agents—The compositions of the present invention may also include one or more dye transfer inhibiting agents. Suitable polymeric dye transfer inhibiting agents include, but are not limited to, polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles or mixtures thereof. When present in the compositions herein, the dye transfer inhibiting agents are present at levels from about 0.0001%, from about 0.01%, from about 0.05% by weight of the cleaning compositions to about 10%, about 2%, or even about 1% by weight of the cleaning compositions. Dispersants—The compositions of the present invention can also contain dispersants. Suitable water-soluble organic materials are the homo- or co-polymeric acids or their salts, in which the polycarboxylic acid may comprise at least two carboxyl radicals separated from each other by not more than two carbon atoms. Enzymes—The compositions can comprise one or more detergent enzymes which provide cleaning performance and/or fabric care benefits. Examples of suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, phospholipases, esterases, cutinases, pectinases, keratanases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, β-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof. A typical combination is a cocktail of conventional applicable enzymes like protease, lipase, cutinase and/or cellulase in conjunction with amylase. Enzyme Stabilizers—Enzymes for use in compositions, for example, detergents can be stabilized by various techniques. The enzymes employed herein can be stabilized by the presence of water-soluble sources of calcium and/or magnesium ions in the finished compositions that provide such ions to the enzymes.
Process of Making
The liquid detergent compositions are in the form of an aqueous solution or uniform dispersion or suspension of surfactant, bluing agent, and certain optional other ingredients, some of which may normally be in solid form, that have been combined with the normally liquid components of the composition, such as the liquid alcohol ethoxylate nonionic, the aqueous liquid carrier, and any other normally liquid optional ingredients. Such a solution, dispersion or suspension will be acceptably phase stable and will typically have a viscosity which ranges from about 100 to 600 cps, or from about 150 to 400 cps. For purposes of this invention, viscosity is measured with a Brookfield LVDV-II+ viscometer apparatus using a #21 spindle.
The liquid detergent compositions herein can be prepared by combining the components thereof in any convenient order and by mixing, e.g., agitating, the resulting component combination to form a phase stable liquid detergent composition. In a process for preparing such compositions, a liquid matrix is formed containing at least a major proportion, or even substantially all, of the liquid components, e.g., nonionic surfactant, the non-surface active liquid carriers and other optional liquid components, with the liquid components being thoroughly admixed by imparting shear agitation to this liquid combination. For example, rapid stirring with a mechanical stirrer may usefully be employed. While shear agitation is maintained, substantially all of any anionic surfactants and the solid form ingredients can be added. Agitation of the mixture is continued, and if necessary, can be increased at this point to form a solution or a uniform dispersion of insoluble solid phase particulates within the liquid phase. After some or all of the solid-form materials have been added to this agitated mixture, particles of any enzyme material to be included, e.g., enzyme prills, are incorporated. As a variation of the composition preparation procedure hereinbefore described, one or more of the solid components may be added to the agitated mixture as a solution or slurry of particles premixed with a minor portion of one or more of the liquid components. After addition of all of the composition components, agitation of the mixture is continued for a period of time sufficient to form compositions having the requisite viscosity and phase stability characteristics. Frequently this will involve agitation for a period of from about 30 to 60 minutes.
In one aspect of forming the liquid detergent compositions, the bluing agent is first combined with one or more liquid components to form a bluing agent premix, and this bluing agent premix is added to a composition formulation containing a substantial portion, for example more than 50% by weight, more specifically, more than 70% by weight, and yet more specifically, more than 90% by weight, of the balance of components of the laundry detergent composition. For example, in the methodology described above, both the bluing agent premix and the enzyme component are added at a final stage of component additions. In another aspect, the bluing agent is encapsulated prior to addition to the detergent composition, the encapsulated bluing agent is suspended in a structured liquid, and the suspension is added to a composition formulation containing a substantial portion of the balance of components of the laundry detergent composition.
As noted previously, the detergent compositions may be in a solid form. Suitable solid forms include tablets and particulate forms, for example, granular particles, flakes or sheets. Various techniques for forming detergent compositions in such solid forms are well known in the art and may be used herein. In one aspect, for example when the composition is in the form of a granular particle, the bluing agent is provided in particulate form, optionally including additional but not all components of the laundry detergent composition. The bluing agent particulate is combined with one or more additional particulates containing a balance of components of the laundry detergent composition. Further, the bluing agent, optionally including additional but not all components of the laundry detergent composition, may be provided in an encapsulated form, and the bluing agent encapsulate is combined with particulates containing a substantial balance of components of the laundry detergent composition.
The compositions of this invention, prepared as hereinbefore described, can be used to form aqueous washing solutions for use in the laundering of fabrics. Generally, an effective amount of such compositions is added to water, for example in a conventional fabric laundering automatic washing machine, to form such aqueous laundering solutions. The aqueous washing solution so formed is then contacted, typically under agitation, with the fabrics to be laundered therewith. An effective amount of the liquid detergent compositions herein added to water to form aqueous laundering solutions can comprise amounts sufficient to form from about 500 to 7,000 ppm of composition in aqueous washing solution, or from about 1,000 to 3,000 ppm of the detergent compositions herein will be provided in aqueous washing solution.
Method of Use
Certain of the consumer products disclosed herein can be used to clean or treat a situs inter alia a surface or fabric. Typically at least a portion of the situs is contacted with an embodiment of Applicants' consumer product, in neat form or diluted in a liquor, for example, a wash liquor and then the situs may be optionally washed and/or rinsed. In one aspect, a situs is optionally washed and/or rinsed, contacted with an aspect of the consumer product and then optionally washed and/or rinsed. For purposes of the present invention, washing includes but is not limited to, scrubbing, and mechanical agitation. The fabric may comprise most any fabric capable of being laundered or treated in normal consumer use conditions. Liquors that may comprise the disclosed compositions may have a pH of from about 3 to about 11.5. Such compositions are typically employed at concentrations of from about 500 ppm to about 15,000 ppm in solution. When the wash solvent is water, the water temperature typically ranges from about 5° C. to about 90° C. and, when the situs comprises a fabric, the water to fabric ratio is typically from about 1:1 to about 30:1. Employing one or more of the aforementioned methods results in a treated situs.
EXAMPLES
The following examples are provided to further illustrate the bluing agents of the present invention; however, they are not to be construed as limiting the invention as defined in the claims appended hereto. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in this invention without departing from the scope or spirit of the invention. All parts and percents given in these examples are by weight unless otherwise indicated.
Sample Preparation and Test Methods
A. Sample Preparation
The following bis-azo colorants are prepared as described herein. The UV-visible spectrum of each colorant is determined by dissolving it in a suitable solvent, typically water or methanol, at a concentration that gives an absorbance at the lambda max of less than 1.0 at a path length of 1.0 cm. A Beckman Coulter DU 800 spectrophotometer was used to measure the UV-visible spectrum and determine the lambda max (“λ max ”) of each sample.
Example 1
To an aqueous suspension of 11.68 grams of p-acetamidobenzenesuffonyl chloride cooled to 15-20° C. is added 8.15 grams of 3-(2-(2-hydroxyethoxy)ethoxy)propylamine at a rate sufficient to keep the temperature below 20° C. Aqueous sodium hydroxide solution is added as needed to keep the pH at >7.After 2 hours of stirring, the reaction is complete and 50 ml of concentrated hydrochloric acid is added, and the mixture refluxed until the infrared spectrum indicated that the acetyl group has been cleaved. The mixture is cooled to 0-5° C. and 3.58 grams of sodium nitrite is added to the mixture and stirred for 2 hours. The resulting diazonium salt is added to a cooled solution of 6.85 grams of 2-methoxy-5-methylaniline in dilute aqueous hydrochloric acid resulting in a deep orange red product. This product is further diazotized at 0-5° C. by adding 3.58 grams of sodium nitrite with additional hydrochloric acid as necessary to keep the pH at <2. The mixture is stirred for 2 hours. The resulting diazonium salt is added to a cooled (0-5° C.) aqueous solution of H-acid in water containing sufficient sodium hydroxide to dissolve the acid. The pH of the reaction mixture is kept at 10-12 during the addition of the diazonium salt by adding sodium hydroxide solution as necessary. This resulted in a solution of the deep violet colored product represented as Formula BA4 herein. The product has a (“λ max ”) of 569 nm in water.
Example 2
The product represented as Formula BA13 herein is prepared in a similar manner to Example 1 except 7.65 grams of 2,5-dimethoxyaniline are substituted for 2-methoxy-5-methylaniline. The product has a (“λ max ”) 583 nm in water.
Example 3
The product represented as Formula BA31 herein is prepared in a similar manner to Example 1 except 9.75 grams of N-acetyl-H acid are substituted for H acid. The product has a (“λ max ”) of 560 nm in water.
Example 4
The product represented as Formula BA58 herein is prepared in a similar manner to Example 1 except 15.75 grams of N-phenyl J acid are substituted for H acid. The product has a (“λ max ”) 545 nm in water.
Example 5
The product represented as Formula BA67 herein is prepared in a similar manner to Example 2 except 15.75 grams of N-phenyl J acid are substituted for H acid. The product has a (“λ max ”) of 558 nm in water.
Example 6
The product represented as Formula BA5 herein is prepared in a similar manner to Example 1 except 8.85 grams of 3-(2-(2-methoxyethoxy)ethoxy)propylamine are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 577 nm in water.
Example 7
The product represented as Formula BA14 herein is prepared in a similar manner to Example 6 except 7.65 grams of 2,5-dimethoxyaniline are substituted for 2-methoxy-5-methylaniline. The product has a (“λ max ”) 608 nm in methanol.
Example 8
The product represented as Formula BA12 herein is prepared in a similar manner to Example 7 except 30.70 grams of Surfonamine® B60 are substituted for 3-(2-(2-methoxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) 590 nm in water.
Example 9
The product represented as Formula BA2 herein is prepared in a similar manner to Example 6 except 52.90 grams of Surfonamine® L100 are substituted for 3-(2-(2-methoxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 581 nm in water.
Example 10
The product represented as Formula BA11 herein is prepared in a similar manner to Example 8 except 52.90 grams of Surfonamine® L100 are substituted for 3-(2-(2-methoxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 578 nm in water.
Example 11
To a cold (0-5° C.) solution of p-polyalkyleneoxyphenylamine (27.45 grams in 100 ml of water), containing sufficient hydrochloric acid to give a pH of 1, are added 3.58 grams of sodium nitrite. The mixture is stirred for 2 hours. The mixture is then added to a cold solution of 7.65 grams of 2,5-dimethoxyaniline in dilute hydrochloric acid to give an orange colored product. This product is further diazotized by adding sufficient hydrochloric acid to keep the pH at 1 followed by 3.58 grams of sodium nitrite. After stirring 2 hours at 0-5° C., the mixture is added to an aqueous solution of 15.85 grams of H acid along with sufficient sodium hydroxide to dissolve the H acid. During the addition of the diazonium salt, the pH is kept at 10-12 by the addition of aqueous sodium hydroxide solution. This resulted in a violet colored product represented as Formula BA18 herein. The product has a (“λ max ”) of 574 nm in methanol.
Example 12
The product represented as Formula BA15 herein is prepared in a similar manner to Example 2 except 27.45 grams of p-polyalkyleneoxyphenylamine are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 574 nm in methanol.
Example 13
The product represented as Formula BA17 herein is prepared in a similar manner to Example 2 except 5.25 grams of diethanolamine are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 581 nm in water.
Example 14
The product represented as Formula BA1 herein is prepared in a similar manner to Example 1 except 35.75 grams of Jeffamine® M715 are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) 578 nm in water.
Example 15
The product represented as Formula BA28 herein is prepared in a similar manner to Example 3 except 35.75 grams of Jeffamine® M715 are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 563 nm in water.
Example 16
The product represented as Formula BA55 herein is prepared in a similar manner to Example 4 except 35.75 grams of Jeffamine® M715 are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 545 nm in methanol.
Example 17
The product represented as Formula BA34 herein is prepared in a similar manner to Example 3 except 3.65 grams of diethylamine are substituted for 3-(2-(2-hydroxyethoxy)ethoxy)propylamine. The product has a (“λ max ”) of 560 nm in water.
Example 18
The product represented as Formula BA61 herein is prepared in a similar manner to Example 17 except 15.75 grams of N-phenyl J acid are substituted for N-acetyl H acid. The product has a (“λ max ”) of 551 nm in methanol.
Example 19
The product represented as Formula BA7 herein is prepared in a similar manner to Example 17 except 15.90 grams of H acid are substituted for N-acetyl H acid. The product has a (“λ max ”) of 599 nm in methanol.
The bis-azo colorants set forth in Table A conform generally to Structure (II) and are prepared according to the methods described herein.
TABLE A
Bis-Azo Colorants
Sample
No.
R1
R2
W
X
Y
Z
Example
CH 3 O
CH 3
3-(2-(2-
NH 2
SO 3 Na
SO 3 Na
1
hydroxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3 O
3-(2-(2-
NH 2
SO 3 Na
SO 3 Na
2
hydroxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3
3-(2-(2-
NHAcetyl
SO 3 Na
SO 3 Na
3
hydroxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3
3-(2-(2-
H
SO 3 Na
NHPhenyl
4
hydroxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3 O
3-(2-(2-
H
SO 3 Na
NHPhenyl
5
hydroxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3
3-(2-(2-
NH 2
SO 3 Na
SO 3 Na
6
methoxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3 O
3-(2-(2-
NH 2
SO 3 Na
SO 3 Na
7
methoxyethoxy)
ethoxy)
propylamino
Example
CH 3 O
CH 3 O
Surfonamine ®
NH 2
SO 3 Na
SO 3 Na
8
B60
Example
CH 3 O
CH 3
Surfonamine ®
NH 2
SO 3 Na
SO 3 Na
9
L100
Example
CH 3 O
CH 3 O
Surfonamine ®
NH 2
SO 3 Na
SO 3 Na
10
L100
Example
CH 3 O
CH 3 O
p-polyalkyl-
NH 2
SO 3 Na
SO 3 Na
12
eneoxyphenyl
amino
Example
CH 3 O
CH 3 O
Dihydroxyethyl-
NH 2
SO 3 Na
SO 3 Na
13
amino
Example
CH 3 O
CH 3
Jeffamine ®
NH 2
SO 3 Na
SO 3 Na
14
M715
Example
CH 3 O
CH 3
Jeffamine ®
NHAcetyl
SO 3 Na
SO 3 Na
15
M715
Example
CH 3 O
CH 3
Jeffamine ®
H
SO 3 Na
NHPhenyl
16
M715
Example
CH 3 O
CH 3
Diethylamino
NHAcetyl
SO 3 Na
SO 3 Na
17
Example
CH 3 O
CH 3
Diethylamino
H
SO 3 Na
NHPhenyl
18
Example
CH 3 O
CH 3
Diethylamino
NH 2
SO 3 Na
SO 3 Na
19
Surfonamine ® and Jeffamine ® products are amino terminated polyalkyleneoxy ethers available from Huntsman Corporation of The Woodlands, Texas that have the general structure:
For Example 11, which conforms generally to Structure (I), R 1 ═OCH 3 , R 2 ═OCH 3 , R 3 =6-substituted H acid, and X=p-polyalkyleneoxyphenylazo.
The chemical names for the corresponding colorants of Table A are respectively provided in Table B below. The chemical names are determined using ChemDraw Ultra; Version 7.0.1, available from CambridgeSoft, Cambridge, Mass., USA.
TABLE B
Chemical Names for Bis-Azo Colorants
Sample
No.
Chemical Name
Example 1
5-Amino-4-hydroxy-3-[4-(4-{3-[2-(2-hydroxy-ethoxy)-ethoxy]-propylsulfamoyl}-
phenylazo)-2-methoxy-5-methyl-phenylazo]-naphthalene-2,7-disulfonic acid,
disodium salt
Example 2
5-Amino-4-hydroxy-3-[4-(4-{3-[2-(2-hydroxy-ethoxy)-ethoxy]-propylsulfamoyl}-
phenylazo)-2,5-dimethoxy-phenylazo]-naphthalene-2,7-disulfonic acid,
disodium salt
Example 3
5-Acetylamino-4-hydroxy-3-[4-(4-{3-[2-(2-hydroxy-ethoxy)-ethoxy]-
propylsulfamoyl}-phenylazo)-5-methoxy-2-methyl-phenylazo]-naphthalene-
2,7-disulfonic acid, disodium salt
Example 4
4-Hydroxy-3-[4-(4-{3-[2-(2-hydroxy-ethoxy)-ethoxy]-propylsulfamoyl}-
phenylazo)-5-methoxy-2-methyl-phenylazo]-7-phenylamino-naphthalene-
2-sulfonic acid, sodium salt
Example 5
4-Hydroxy-3-[4-(4-{3-[2-(2-hydroxy-ethoxy)-ethoxy]-propylsulfamoyl}-
phenylazo)-2,5-dimethoxy-phenylazo]-7-phenylamino-naphthalene-2-
sulfonic acid, sodium salt
Example 6
5-Amino-4-hydroxy-3-[2-methoxy-4-(4-{3-[2-(2-methoxyethoxy)-ethoxy]-
propylsulfamoyl}-phenylazo)-5-methyl-phenylazo]-naphthalene-2,7-
disulfonic acid, disodium salt
Example 7
5-Amino-3-[2,5-dimethoxy-4-(4-{3-[2-(2-methoxy-ethoxy)-ethoxy]-
propylsulfamoyl}-phenylazo)-phenylazo]-4-hydroxy-naphthalene-2,7-
disulfonic acid
Example 8
5-Amino-4-hydroxy-3-[2,5-dimethoxy-4-(4-polyalkyleneoxysulfamoyl
phenylazo)-phenylazo]-naphthalene-2,7-disulfonic acid, disodium salt
Example 9
5-Amino-4-hydroxy-3-[2-methoxy-4-(4-polyalkyleneoxysulfamoyl
phenylazo)-5-methyl-phenylazo]-naphthalene-2,7-disulfonic acid,
disodium salt
Example
5-Amino-4-hydroxy-3-[2,5-dimethoxy-4-(4-polyalkyleneoxysulfamoyl
10
phenylazo)-phenylazo]-naphthalene-2,7-disulfonic acid, disodium salt
Example
5-Amino-4-hydroxy-3-[2,4-dimethoxy-4-(4-polyalkyleneoxyphenyl)sulfamoyl
11
phenylazo]-phenylazo]-naphthalene-2,7-disulfonic acid, disodium salt
Example
5-Amino-4-hydroxy-3-[2,5-dimethoxy-4-(4-polyalkyleneoxysulfamoyl
12
phenylazo)-phenylazo]-naphthalene-2,7-disulfonic acid, disodium salt
Example
5-Amino-3-(4-{4-[bis-(2-hydroxy-ethyl)-sulfamoyl]-phenylazo}-2,5-
13
dimethoxy-phenylazo)-4-hydroxy-naphthalene-2,7-disulfonic acid,
disodium salt
Example
5-Amino-4-hydroxy-3-[4-(4-polyalkyleneoxysulfamoyl-phenylazo)-2-
14
methoxy-5-methyl-phenylazo]-naphthalene-2,7-disulfonic acid,
isodium salt
Example
5-Acetylamino-4-hydroxy-3-[4-polyoxalkyenesulfamoylphenylazo)-5-
15
methoxy-2-methyl-phenylazo]-naphthalene-2,7-disulfonic acid,
disodium salt
Example
4-Hydroxy-3-[4-(4-polyalkyleneoxysulfamoyl-phenylazo)-5-methoxy-2-
16
methyl-phenylazo]-7-phenylamino-naphthalene-2-sulfonic acid,
sodium salt
Example
5-Acetylamino-3-[4-(4-diethylsulfamoyl-phenylazo)-5-methoxy-2-methyl-
17
phenylazo]-4-hydroxy-naphthalene-2,7-disulfonic acid, disodium salt
Example
3-[4-(4-Diethylsulfamoyl-phenylazo)-2-methoxy-5-methyl-phenylazo]-4-
18
hydroxy-7-phenylamino-naphthalene-2-sulfonic acid, sodium salt
Example
5-Amino-3-[4-(4-diethylsulfamoyl-phenylazo)-5-methoxy-2-methyl-
19
phenylazo]-4-hydroxy-naphthalene-2,7-disulfonic acid, disodium salt
Structural representations of Examples 1-19 are provided herein.
B. Test Methods
I. Method for Determining Molar Absorptivity (ε)
The Molar Absorptivity is determined by dissolving a known amount of the compound in a suitable solvent and measuring the absorbance of the solution on an ultraviolet-visible spectrophotometer. The absorptivity is calculated by dividing the absorbance by the molar concentration in moles/liter and the path length which is typically one centimeter.
Washing of Fabric: Each dye is run in a simulated wash of CW120 fabric (16 oz white cotton interlock knit fabric, 270 g/square meter, brightened with Uvitex BNB fluorescent whitening agent, from Test Fabrics. P.O. Box 26, Weston, Pa., 18643) using typical conditions for North American heavy duty laundry detergent (“NA HDL” or “HDL”) (788 ppm dose, 20° C., 6 gpg 3:1 Ca:Mg, 30:1 liquor:fabric ratio, 30 minutes) at six dilutions, with the highest wash water absorbance being set close to a value of 1.0. Fabrics are rinsed once for 5 minutes and air dried.
L*, a* and b* values are measured on each fabric (four internal replicates for each wash condition) using a Hunter LabScan XE reflectance spectrophotometer with D65 illumination, 10° observer and UV filter excluded, and difference values calculated against a nil-dye HDL reference.
II. Method for Determining Specific Deposition (Abs Δb-2 )
From the plot of wash solution absorbance vs. Δb*, the wash solution absorbance necessary to deliver a Δb* of −2.0 on fabric is determined by linear interpolation of the two data points that bracket the target Δb*.
III. Method for Determining Relative Hue Angle (θ R ) and Absolute Hue Angle (θ A )
From a plot of Δa* vs. Δb* for each concentration point of a given compound, the Δa* value at Δb*=−2.0 is determined by interpolation of the two data points that bracketed Δb*=−2.0. The relative hue angle θ R is then calculated as 270+arctan(|Δa*/Δb*|) for positive values of Δa* and 270−arctan(|Δa*/Δb*|) where Δa* is negative.
The Δa* value at Δb*=−2.0 is added to the a* value, and −2.0 is added to the b* value of a tracer fabric washed in nil-dye HDL (a*=2.0; b*=−15.5; average of 24 replicates). The absolute hue angle is determined at the concentration of dye that delivers Δb*=−2.0, using a* Dye and b* Dye as defined below:
a* Dye =a* tracer +Δa* Dye =2.0 +Δa* Dye
b* Dye =b* tracer +Δb* Dye =−15.5+(−2.0)=−17.5.
The absolute hue angle θ A is calculated as 270+arctan(|a* Dye /b* Dye |) for positive values of a* Dye and 270−arctan(|a* Dye /b* Dye |) where a* Dye is negative.
IV. Method for Determining Surface Color
The surface color of an article may be quantified using a series of measurements —L*, a*, and b* —generated by measuring the samples using a spectrophotometer. The equipment used for this test is a Gretag Macbeth Color Eye 7000A spectrophotometer. The software program used is “Color imatch.” “L” is a measure of the amount of white or black in a sample; higher “L” values indicate a lighter colored sample. A measure of the amount of red or green in a sample is determined by “a*” values. A measure of the amount of blue or yellow in a sample is determined by “b*” values; lower (more negative) b* values indicate more blue on a sample.
V. Method for Determining Hueing Efficiency for Detergents
a.) Two 25 cm×25 cm fabric swatches of 16 oz white cotton interlock knit fabric (270 g/square meter, brightened with Uvitex BNB fluorescent whitening agent, from Test Fabrics. P.O. Box 26, Weston, Pa., 18643), are obtained. b.) Prepare two one liter aliquots of tap water containing 1.55 g of AATCC standard heavy duty liquid (HDL) test detergent as set forth in Table 3. c.) Add a sufficient amount the dye to be tested to one of the aliquots from Step b.) above to produce an aqueous solution absorbance of 1 AU. d.) Wash one swatch from a.) above in one of the aliquots of water containing 1.55 g of AATCC standard heavy duty liquid (HDL) test detergent and wash the other swatch in the other aliquot. Such washing step should be conducted for 30 minutes at room temperature with agitation. After such washing step separately rinse the swatches in tap water and air dry the swatches in the dark. e.) After rinsing and drying each swatch, the hueing efficiency, DE* eff , of the dye is assessed by determining the L*, a*, and b* value measurements of each swatch using a Hunter LabScan XE reflectance spectrophotometer with D65 illumination, 10° observer and UV filter excluded. The hueing efficiency of the dye is then calculated using the following equation:
DE* eff =(( L* c −L* s ) 2 +( a* c −a* s ) 2 +( b* c −b* s ) 2 ) 1/2
wherein the subscripts c and s respectively refer to the L*, a*, and b* values measured for the control, i.e., the fabric sample washed in detergent with no dye, and the fabric sample washed in detergent containing the dye to be screened.
VI. Method for Determining Wash Removability
a.) Prepare two separate 150 ml aliquots of HDL detergent solution set forth in Table 1, according to AATCC Test Method 61-2003, Test 2A and containing 1.55 g/liter of the AATCC HDL formula in distilled water. b.) A 15 cm×5 cm sample of each fabric swatch from the Method for Determining of Hueing Efficiency For Detergents described above is washed in a Launderometer for 45 minutes at 49° C. in 150 ml of a the HDL detergent solution prepared according to Step II. a.) above. c.) The samples are rinsed with separate aliquots of rinse water and air dried in the dark, and then L*, a*, and b* value measurements of each swatch are taken using a Hunter LabScan XE reflectance spectrophotometer with D65 illumination, 10° observer and UV filter excluded. The amount of residual coloration is assessed by measuring the DE* res , calculated using the following equation:
DE* res =(( L* c −L* s ) 2 +( a* c −a* s ) 2 +( b* c −b* s ) 2 ) 1/2
wherein the subscripts c and s respectively refer to the L*, a*, and b* values measured for the control, i.e., the fabric sample initially washed in detergent with no dye, and the fabric sample initially washed in detergent containing the dye to be screened. The wash removal value for the dye is then calculated according to the formula: % removal=100×(1−DE* res /DE* eff ).
VII. Method for Determining Staining
This procedure uses three fabric types to determine the propensity of a dye dissolved in a detergent matrix to stain fabric in a manner similar to a home laundry pre-treat scenario. The three primary fibers examined are cotton, nylon, and spandex (a synthetic polymer having urethane blocks) that comprise the following fabrics:
16 oz cotton interlock knit fabric (270 g/square meter, brightened with Uvitex BNB fluorescent whitening agent, obtained from Test Fabrics. P.O. Box 26, Weston, Pa., 18643),
6.3 oz 90% Cotton/10% Lycra®, Stock # CLF, obtained from Dharma Trading Co., 1604 Fourth St. San Rafael, Calif. 94901,
80% Nylon/20% Spandex, Item #983684GN, obtained from Hancock Fabrics, One Fashion Way, Baldwyn, Miss. 38824.
A one inch diameter circle for each of the dyed detergent samples was drawn using a template and labeled with the dye identification on the test fabrics with a non-staining, acrylic ink textile marker (TEXPEN textile marker made by Mark-tex Corp., Englewood, N.J. 07631).
The test fabrics were placed on top of a piece of plastic backed paper counter sheet, or alternatively, a single layer of paper towel over aluminum foil, and stained at the 16 hrs, 1 hr, and 15 min time intervals. Staining was done by placing approximately 0.5 g of the dyed detergent on the fabric allowing it to soak through the fabric with the excess being absorbed by the counter sheet so that the circular test area was saturated with detergent without spreading to adjacent test circles. Due to possible light fading of the dyes, they were placed under a covered area to prevent direct exposure to light while allowing air to pass over the fabrics. The 16 hr stains were applied in the evening while the 1 hr and 15 min swatches were stained the following morning prior to washing. The approximate total amount of detergent applied is calculated by multiplying the total number of stained areas by the amount of detergent delivered for each stain. If this amount exceeds the recommended dosage for the detergent then divide the total detergent by the recommended dosage to determine the number of wash loads to distribute the stained fabrics. If the stained fabrics do not provide the total recommended amount of detergent for a load, then the balance of the detergent is filled with Tide Free (nil-dye) detergent.
The pretreated fabrics are washed in a full scale Kenmore top loading washer with 5.5 lbs of terry washcloths used as ballast under median North American conditions of 17 gallons of 90° F./6 grains per gallon of hardness wash water with a rinse of 60° F./6 grains per gallon of hardness water. After the wash is complete the test fabrics are dried with the ballast in a forced heated air drier at the highest temperature setting for 60 minutes, or until completely dry.
The circled stain areas were analyzed using a Hunter Colorquest or Labscan XE with D65 lighting, UV filter not included and a 0.5″ port opening. A nil-dye pre-treat control stain was used as the instrument reference standard for calculating the DE* because the detergent contains brightener. Visual assessment is done under fluorescent lights with a white paper (92 brightness) background under the swatch. The DE*/Visual Scale allows communication of stain intensity in a non-technical manner.
DE*/Visual Scale
<1 = 0
No visible staining
1-2.5 = 1
Slightly off white area
2.5-5 = 2
Light but visible stain
5-10 = 3
Clearly visible stain
>10 = 4
A dark stain
Test Results
Test 1: Determination of Component Parts of Bis-Azo Colorants
TABLE 1
A, B and C moieties used to construct bluing agents
A—N═N—B—N═N—C.
A Moieties
A1
A2
A3
B Moieties
B1
B2
B3
C Moieties
Cl
C2
C3
C4
C5
C6
C7
C8
C9
Test 2: Determination of Molar Absorptivity of Bis-Azo Colorants
The molar absorptivity (ε) of each example is provided in Table 2.
TABLE 2
Molar Absorptivity of Bis-Azo Colorants
Example
Molar Abs
No.
(ε)
Example 1
28615
Example 2
12399
Example 3
23657
Example 4
26346
Example 5
43706
Example 6
21877
Example 7
27436
Example 8
16620
Example 9
34649
Example 10
15103
Example11
25427
Example 12
8347
Example 13
11223
Example 14
23691
Example 15
28205
Example 16
32492
Example 17
21645
Example 18
34180
Example 19
35408
Test 3: Determination of Deposition and Hue Angle
Table 3 provides the deposition and hue angle for Examples 1-19. The data is sorted by variation in Components A, B and C, as determined previously.
TABLE 3
Deposition and Hue Angle of Bis-Azo Colorants
Relative
Absolute
Hue
Components
Deposition
Hue Angle
Angle
Sample No.
A
B
C
Abs Δb −2
θ A
θ R
Variation
Example 14
1
1
1
0.0778
274.9
256.0
in A
Example 15
2
1
1
0.0584
277.2
275.7
Example 16
3
1
1
0.0436
282.9
315.0
Example 1
1
1
4
0.0463
274.2
250.7
Example 3
2
1
4
0.0170
277.2
275.7
Example 4
3
1
4
0.0341
286.2
327.2
Example 19
1
1
7
0.0375
273.9
248.2
Example 17
2
1
7
0.0245
275.7
262.9
Example 18
3
1
7
0.0181
279.4
294.2
Example 2
1
2
4
0.0345
273.6
245.8
Example 5
3
2
4
0.0140
276.8
272.9
Variation
Example 9
1
1
2
0.0562
274.9
256.0
in B
Example 10
1
2
2
0.1223
274.6
253.3
Example 1
1
1
4
0.0463
274.2
250.7
Example 2
1
2
4
0.0345
273.6
245.8
Example 6
1
1
5
0.0209
274.9
256.0
Example 7
1
2
5
0.0255
272.9
241.2
Example 4
3
1
4
0.0341
286.2
327.2
Example 5
3
2
4
0.0140
276.8
272.9
Variation
Example 14
1
1
1
0.0778
274.9
256.0
in C
Example 14
0.0748
274.9
256.0
Example 9
1
1
2
0.0562
274.9
256.0
Example 1
1
1
4
0.0463
274.2
250.7
Example 6
1
1
5
0.0209
274.9
256.0
Example 19
1
1
7
0.0375
273.9
248.2
Example 10
1
2
2
0.1223
274.6
253.3
Example 8
1
2
3
0.0925
272.3
237.0
Example 2
1
2
4
0.0345
273.6
245.8
Example 7
1
2
5
0.0255
272.9
241.2
Example 12
1
2
6
0.0347
274.2
250.7
Example 13
1
2
8
0.0409
272.0
235.0
Example 11
1
2
9
0.0905
274.9
256.0
Example 15
2
1
1
0.0584
277.2
275.7
Example 3
2
1
4
0.0170
277.2
275.7
Example 3
0.0168
275.9
264.3
Example 17
2
1
7
0.0245
275.7
262.9
Example 16
3
1
1
0.0436
282.9
315.0
Example 4
3
1
4
0.0341
286.2
327.2
Example 18
3
1
7
0.0181
279.4
294.2
With respect to the data contained in Table 3, absolute hue angle describes the actual hue angle of the fabric on the a*, b* plane. This is the angle that a consumer actually sees when looking at the fabric. Relative hue angle is determined against a tracer fabric washed in nil-dye HDL (i.e. same detergent, but without dye), and thus gives the movement within the a*, b* plane relative to the nil-dye control.
Thus, the bluing agent of the present invention may have an absolute hue angle in the range of 265° to 310°, 265° to 300°, 265° to 295°, 270° to 295°, 270° to 290°, or even in the range of 273° to 287°.
Exemplary Detergent Formulations
Formulations 1a-1l
Liquid Detergent Formulations
Tables 4A and 4B provide examples of liquid detergent formulations which include at least one bluing agent of the present invention. The formulations are shown in Table 4A as Formulations 1a through 1f and in Table 4B as Formulations 1g through 1l.
TABLE 4A
Liquid Detergent Formulations Comprising the Inventive Bluing Agent
1a
1b
1c
1d
1e
1f 5
Ingredient
wt %
wt %
wt %
wt %
wt %
wt %
sodium alkyl ether sulfate
14.4%
14.4%
9.2%
5.4%
linear alkylbenzene sulfonic
4.4%
4.4%
12.2%
5.7%
1.3%
22.0%
acid
alkyl ethoxylate
2.2%
2.2%
8.8%
8.1%
3.4%
18.0%
amine oxide
0.7%
0.7%
1.5%
citric acid
2.0%
2.0%
3.4%
1.9%
1.0%
1.6%
fatty acid
3.0%
3.0%
8.3%
16.0%
protease
1.0%
1.0%
0.7%
1.0%
2.5%
amylase
0.2%
0.2%
0.2%
0.3%
lipase
0.2%
borax
1.5%
1.5%
2.4%
2.9%
calcium and sodium formate
0.2%
0.2%
formic acid
1.1%
amine ethoxylate polymers
1.8%
1.8%
2.1%
3.2%
sodium polyacrylate
0.2%
sodium polyacrylate copolymer
0.6%
DTPA 1
0.1%
0.1%
0.9%
DTPMP 2
0.3%
EDTA 3
0.1%
fluorescent whitening agent
0.15%
0.15%
0.2%
0.12%
0.12%
0.2%
ethanol
2.5%
2.5%
1.4%
1.5%
propanediol
6.6%
6.6%
4.9%
4.0%
15.7%
sorbitol
4.0%
ethanolamine
1.5%
1.5%
0.8%
0.1%
11.0%
sodium hydroxide
3.0%
3.0%
4.9%
1.9%
1.0%
sodium cumene sulfonate
2.0%
silicone suds suppressor
0.01%
perfume
0.3%
0.3%
0.7%
0.3%
0.4%
0.6%
Non-tinting dyes 4
0.0001%
0.001%
0.008%
0.03%
0.015%
0.05%
First bis-azo colorant 6
0.001%
0.001%
0.0005%
Second bis-azo colorant 6
0.013%
0.005%
0.003%
0.001%
water
balance
balance
balance
balance
balance
balance
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
TABLE 4B
Liquid Detergent Formulations Comprising the Inventive Bluing Agent
1g
1h
1i
1j
1k
1l 5
Ingredient
wt %
wt %
wt %
wt %
wt %
wt %
sodium alkyl ether sulfate
14.4%
14.4%
9.2%
5.4%
linear alkylbenzene sulfonic
4.4%
4.4%
12.2%
5.7%
1.3%
22.0%
acid
alkyl ethoxylate
2.2%
2.2%
8.8%
8.1%
3.4%
18.0%
amine oxide
0.7%
0.7%
1.5%
citric acid
2.0%
2.0%
3.4%
1.9%
1.0%
1.6%
fatty acid
3.0%
3.0%
8.3%
16.0%
protease
1.0%
1.0%
0.7%
1.0%
1.7%
amylase
0.2%
0.2%
0.2%
0.6%
lipase
0.2%
0.2%
borax
1.5%
1.5%
2.4%
2.9%
calcium and sodium formate
0.2%
0.2%
formic acid
1.1%
amine ethoxylate polymers
1.8%
1.8%
2.1%
3.2%
sodium polyacrylate
0.2%
sodium polyacrylate copolymer
0.6%
DTPA 1
0.1%
0.1%
0.9%
DTPMP 2
0.3%
EDTA 3
0.1%
fluorescent whitening agent
0.15%
0.15%
0.2%
0.12%
0.12%
0.2%
ethanol
2.5%
2.5%
1.4%
1.5%
propanediol
6.6%
6.6%
4.9%
4.0%
15.7%
sorbitol
4.0%
ethanolamine
1.5%
1.5%
0.8%
0.1%
11.0%
sodium hydroxide
3.0%
3.0%
4.9%
1.9%
1.0%
sodium cumene sulfonate
2.0%
silicone suds suppressor
0.01%
perfume
0.3%
0.3%
0.7%
0.3%
0.4%
0.6%
Non-tinting dyes 4
0.0001%
0.001%
0.008%
0.03%
0.015%
0.05%
First bis-azo colorant 6
0.01%
0.005%
0.005%
Second bis-azo colorant 6
0.01%
0.02%
0.003%
0.012%
opacifier 7
0.5%
water
balance
balance
balance
balance
balance
balance
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
Footnotes for Formulations 1a-I:
1 diethylenetriaminepentaacetic acid, sodium salt
2 diethylenetriaminepentakismethylenephosphonic acid, sodium salt
3 ethylenediaminetetraacetic acid, sodium salt
4 a non-tinting dye or mixture of non-tinting dyes used to adjust formula color
5 compact formula, packaged as a unitized dose in polyvinyl alcohol film
6 Bis-azo colorants selected from Examples 1-19, preferably with hueing efficiency >10 and wash removability 30-85%
7 Acusol OP301
Formulations 2a-2e
Granular Detergent Formulations
Table 5 provides examples of granular detergent formulations which include at least one bluing agent of the present invention. The formulations are shown in Table 5 as Formulations 2a through 2e.
TABLE 5
Granular Detergent Formulations Comprising the
Inventive Bluing Agent
2a
2b
2c
2d
2e
Ingredient
wt %
wt %
wt %
wt %
wt %
Na linear alkylbenzene sulfonate
3.4%
3.3%
11.0%
3.4%
3.3%
Na alkylsulfate
4.0%
4.1%
4.0%
4.1%
Na alkyl sulfate (branched)
9.4%
9.6%
9.4%
9.6%
alkyl ethoxylate
3.5%
type A zeolite
37.4%
35.4%
26.8%
37.4%
35.4%
sodium carbonate
22.3%
22.5%
35.9%
22.3%
22.5%
sodium sulfate
1.0%
18.8%
1.0%
sodium silicate
2.2%
protease
0.1%
0.2%
0.1%
0.2%
sodium polyacrylate
1.0%
1.2%
0.7%
1.0%
1.2%
carboxymethylcellulose
0.1%
PEG 600
0.5%
0.5%
PEG 4000
2.2%
2.2%
DTPA
0.7%
0.6%
0.7%
0.6%
fluorescent whitening agent
0.1%
0.1%
0.1%
0.1%
0.1%
sodium percarbonate
5.0%
5.0%
sodium nonanoyloxybenzenesulfonate
5.3%
5.3%
silicone suds suppressor
0.02%
0.02%
0.02%
0.02%
perfume
0.3%
0.3%
0.2%
0.3%
0.3%
First bis-azo colorant 1
0.004%
0.001%
0.02%
Second bis-azo colorant 1
0.006%
0.002%
0.004%
water and miscellaneous
balance
balance
Balance
balance
balance
100.0%
100.0%
100.0%
100.0%
100.0%
1 Bis-azo colorants selected from Examples 1-19, preferably with hueing efficiency >10 and wash removability of 30-85%.
Exemplary Fabric Care Compositions
Formulations 3a-3d
Liquid Fabric Care Compositions
Table 6 provides examples of liquid fabric care compositions which include at least one bluing agent of the present invention. The compositions are shown in Table 6 as Formulations 3a through 3d.
TABLE 6
Liquid Fabric Care Compositions
Comprising the Inventive Bluing Agent
Ingredients
3a
3b
3c
3d
Fabric Softening Active a
13.70%
13.70%
13.70%
13.70%
Ethanol
2.14%
2.14%
2.14%
2.14%
Cationic Starch b
2.17%
2.17%
2.17%
2.17%
Perfume
1.45%
1.45%
1.45%
1.45%
Phase Stabilizing
0.21%
0.21%
0.21%
0.21%
Polymer c
Calcium Chloride
0.147%
0.147%
0.147%
0.147%
DTPA d
0.007%
0.007%
0.007%
0.007%
Preservative e
5 ppm
5 ppm
5 ppm
5 ppm
Antifoam f
0.015%
0.015%
0.015%
0.015%
First bis-azo colorant i
30 ppm
15 ppm
Second bis-azo colorant i
30 ppm
Third bis-azo colorant i
30 ppm
15 ppm
Tinopal CBS-X g
0.2
0.2
0.2
0.2
Ethoquad C/25 h
0.26
0.26
0.26
0.26
Ammonium Chloride
0.1%
0.1%
0.1%
0.1%
Hydrochloric Acid
0.012%
0.012%
0.012%
0.012%
Deionized Water
Balance
Balance
Balance
Balance
a N,N-di(tallowoyloxyethyl)-N,N-dimethylammonium chloride.
b Cationic starch based on common maize starch or potato starch, containing 25% to 95% amylose and a degree of substitution of from 0.02 to 0.09, and having a viscosity measured as Water Fluidity having a value from 50 to 84.
c Copolymer of ethylene oxide and terephthalate having the formula described in U.S. Pat. No. 5,574,179 at col. 15, lines 1-5, wherein each X is methyl, each n is 40, u is 4, each R 1 is essentially 1,4-phenylene moieties, each R 2 is essentially ethylene, 1,2-propylene moieties, or mixtures thereof.
d Diethylenetriaminepentaacetic acid.
e KATHON ® CG available from Rohm and Haas Co.
f Silicone antifoam agent available from Dow Corning Corp. under the trade name DC2310.
g Disodium 4,4′-bis-(2-sulfostyryl) biphenyl, available from Ciba Specialty Chemicals.
h Cocomethyl ethoxylated [15] ammonium chloride, available from Akzo Nobel.
i Bis-azo colorants selected from Examples 1-19, preferably with hueing efficiency >10 and wash removability of 30-85%.
Accordingly, the present invention provides a bluing agent for textile and/or paper substrates comprising at least one chromophore component that comprises a bis-azo colorant and at least one polymeric component. A laundry detergent composition and a rinse added fabric softener containing such a bluing agent is also contemplated herein.
* * *
While particular aspects of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
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This invention relates to bis-azo colorants for use as bluing agents, laundry care compositions comprising bis-azo colorants that may serve as bluing agents, processes for making such bluing agents and laundry care compositions and methods of using the same. The bluing agents are generally comprised of at least two components: at least one chromophore component and at least one polymeric component. These bluing agents are advantageous in providing a whitening effect to fabrics, while not building up over time and causing undesirable blue discoloration to the treated fabrics.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This disclosure relates to random access memory and specifically to a serial address generator for a burst-type random access memory.
2. Description of the Prior Art
Video RAM (random access memory), synchronous RAM and burst RAM each require a sequence of internally generated addresses for faster cycling and prevention of the external address bus lines from fast switching to suppress switching noise in the system. Typically the start address of a particular address burst is provided from an external source (a host computer or a processor) and as subsequent clock signals arrive at the address generator, the following addresses in the burst are generated continuously in sequence for the duration of the burst. The prior art presets the address sequencer (typically a counter) to the externally provided start address (A n ) in response to a PRESET signal. The address sequencer output is updated with each φ clock rising edge, and the outputs of the address generator are sequentially A n , A n+1 , A n+2 , etc.
Such a prior art address generator is shown in FIG. 1A including address sequencer 12 outputting the sequence of addresses to an output buffer 14. The three input signals to the address sequencer 12 are the input address signal (the start address A n ), the φ clock signal, and the PRESET signal. Additionally, a sequence control signal controls whether the address sequencer 12 counts up or down. In most applications, upcounting is used, and this function is built in, rather than being a control function. The associated timing diagram is shown in FIG. 2A.
Typically the address sequencer 12 (counter) includes a master side and a slave side, each initially set to the start address A n . It is to be understood that the device of FIG. 1A is a parallel device, where the start address A n is a multi-bit address provided by a plurality of lines, i.e. an address bus. The address out signal is also provided on a multi-line bus.
As seen in FIG. 2A, the first address out A n is output to buffer 14 when the Preset signal is applied, and kept until leading edge of φ clock arrives. The second address out A n+1 is output to buffer 14 at the trailing edge of φ clock and the following addresses are updated at every trailing edge of the φ clock signal.
The address generator of FIG. 1A functions adequately; however it is slower than desired. Faster operation is desirable to improve system performance such as needed in a typical burst DRAM (dynamic random access memory) chip. The FIG. 1A address generator delivers the first address late, due to the propagation delay through the counters inside the address sequencer. This means a shorter start address duration time.
To improve the start address delivery, in a second prior art address generator the start address is provided from the Address Input directly, instead of going through the counters. (See FIG. 1B, and corresponding timing diagram FIG. 2B).
Rather than providing the start address A n to the address sequencer as in FIG. 1A, the address sequencer 12 of FIG. 1B is bypassed before and during the preset period by means of external address enable switch 24 and internal address enable switch 26, and the start address is provided directly to the output buffer via external address enable switch 24. This (start) address A n is therefore available almost immediately as the address out at buffer 14, without processing by the address sequencer 12.
However, further performance improvement (i.e., higher speed) is desirable in terms of address output.
SUMMARY OF THE INVENTION
In the above described prior art, the second address A n+1 is delivered by the address sequencer to the output buffer at the time of the trailing edge of the first φ clock cycle. In accordance with the invention, instead the second address A n+1 is delivered to the output buffer at the leading edge of the φ clock signal. Thus one half of a clock cycle is gained for each address burst.
After provision to the output buffer of the first address A n (which is externally supplied as in FIG. 1B) the external address line is disconnected from the output buffer by an external address enable switch, and an internal address enable switch which connects the address sequencer to the output buffer is closed, allowing the address sequencer to provide the subsequent internally generated address A n+1 to the output buffer, also as in FIG. 1B. Then, during the time that the start address A n is being provided to the output buffer, the address sequencer operates to calculate the subsequent address A n+1 . The output addresses of each burst are thereby, each provided to the output buffer approximately 1/2 of a clock cycle earlier than in the prior art of FIG. 1B.
The externally provided address and the address out both begin with the same address A n which is the initial address in the burst, while using the preset signal to advance the counting of the sequence by one count.
Therefore, the address sequencer is preset to address A n+1 (the second address in the burst) following the externally provided start address A n . When the first clock signal arrives at the address sequencer, the address sequencer output is sampled by enabling the internal address enable (second) switch and disabling the external address enable (first) switch. The address sequencer output is updated with each rising edge of the clock signal φ clock . Thereby the address sequencer generates each address one clock cycle ahead of the time that address would have been generated in the prior art, and the address output is supplied to the output buffer 1/2 clock cycle ahead of the prior art (FIG. 2B) timing. As in the prior art, the address sequencer includes a master/slave counter. However, in accordance with the invention and in order to set the address sequencer initially to the second address A n+1 , the master side of the counter is initially set to value A n , and the slave side of the counter is initially set to value A n+1 . This provides the desired incremental timing advantage over the prior art.
The present invention is applicable specifically to burst DRAM (dynamic RAM) operating in page mode, and is also applicable to other types of burst memory using sequential type addressing.
In accordance with the invention, operation of the address generator is the same as in the prior art except during the preset cycle. Thus the performance advantage is gained during the preset portion of the address burst. Since the addresses are output one-half cycle ahead of that provided in the prior art, this improves the operational performance of the system in which the burst memory is installed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B show prior art address generators.
FIGS. 2A, 2B show timing diagrams for the prior art address generators of respectively FIGS. 1A, 1B.
FIG. 3 shows an address generator in accordance with the present invention.
FIG. 4 shows a timing diagram for the address generator of FIG. 3.
FIG. 5 shows a schematic of the internal address enable switch, external address enable switch, and output buffer in accordance with the present invention.
FIG. 6 shows a counter in accordance with the present invention.
FIG. 7 shows detail of one cell of the counter of FIG. 6.
FIGS. 8, 9, and 10 show circuitry for generation of the timing signals for the address generator in accordance with the present invention.
FIGS. 11(a) and 11(b) show a timing diagram for an address generator in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows in a block diagram serial address generator 18 in accordance with the invention. Address generator 18 includes address sequencer 20, output buffer 22, external address enable switch 24 (as in FIG. 1B) actuated by an external address enable control signal 28, and internal address enable switch 26 (as in FIG. 1B) actuated by an internal address enable control signal 30. Thus the serial address generator of FIG. 3 appears in the block diagram to be similar to the serial address generator of FIG. 1B; the distinction is in the internal structure and operation of address sequencer 20, which differs significantly from address sequencer 12 of FIGS. 1A and 1B.
Sequence control signal 32 (as in the prior art) determines whether address sequencer 20 is an up or down counter. Input signals on lines 34, 36 and 38 are conventional (as in the prior art). The output address ("address out") is provided on line 40. This circuit, like that of FIGS. 1A and 1B, is a parallel device providing a multi-bit address. Hence address line 34, the output from the address sequencer on line 42, and the address out line 40 each represent multi-line busses with as many lines as there are address bits in the particular application.
FIG. 4 illustrates timing for the address generator of FIG. 3, and specifically the timing for external address switch 24 and internal address switch 26 as controlled respectively by their control signals 28, 30 of FIG. 3. Initially, external address enable switch 24 is closed (the external address enable control signal 28 is high) thus providing the externally provided address on line 34 directly to buffer 22. After the initial address A n (which is externally provided) is provided to buffer 22, the signal φ clock goes low, and the external address enable control signal 28 goes low, then the internal address enable signal 30 goes high, closing switch 26. At this time the address sequencer 20 has generated the second address A n+1 .
As seen in the timing diagram of FIG. 4, generation of the second address A n+1 overlaps with provision of the start address A n . Thus within the first two φ clock cycles, all of start address A n and second address A n+1 are output to buffer 22, in contrast to the prior art of FIG. 2B in which only 11/2 addresses are outputted within the first two occurrences of clock cycles φ clock . This half-clock cycle advantage is the chief benefit of the present invention. Thus the generation of addresses ("Address sequencer out" in FIG. 4) is one clock cycle ahead of that in the prior art, and there is also a half clock timing advantage in the output addresses ("Address out") in contrast to the prior art of FIG. 2B.
In one embodiment the serial address generator of FIG. 3 is for use in a burst RAM operating in page mode, with the externally provided address being the first (start) address for each page. Therefore for example a RAM chip having 512 words per page requires nine bit addresses, i.e., 2 9 =512. Thus, the address sequencer is a nine-bit counter. The serial address generator in accordance with the invention is also be suitable for other (non-page mode) types of serially generated addresses, with the addition of conventional stop circuitry to terminate a burst of predetermined length.
It is to be appreciated that the serial address generator of FIG. 3 is used in place of conventional serial address generator of FIGS. 1A, 1B as a portion typically of a RAM chip. The address out signal provided on line 40 is conventionally connected to an address decoder which selects the desired memory cell or cells to be written to or read from. (The remainder of the RAM chip is not illustrated herein as being conventional.)
FIGS. 5 through 10 show a detailed schematic of one embodiment of the present invention, corresponding to that shown in the block diagram of FIG. 3 except that the sequence control is not shown, due to only upcounting being available. In FIGS. 5 through 10 the small numbers adjacent each logic gate indicate the width (in micrometers) of each transistor gate of the logic gate. Thus, "P" indicates the width of a P channel transistor gate and "N" indicates the width of an N channel transistor gate. The gate length is equal for all transistors except where a two number notation is used i.e., "48/2" means the transistor gate width is 48 micrometers and the transistor gate length is 2 micrometers. The standard (default) transistor gate length is 1.2 micrometers, for this embodiment.
Table 1 shows the signal designations in the block diagram FIG. 3 and the corresponding signal designations in schematic FIGS. 5 to 10, and in the corresponding timing diagram of FIGS. 11(a), 11(b). In Table 1 there is no schematic equivalent to the sequence control signal in FIG. 3, since as explained above the circuit shown in the schematic of FIGS. 5 to 10 uses "up counting" only and does not have a down counting mode option.
TABLE 1______________________________________CHIEF SIGNALS - EQUIVALENCESBLOCK TIMINGDIAGRAM SCEMATIC - CHARTFIG. 3 FIGS. 5-10FIG. 11______________________________________Start address Same Yn(An)PRESET Same SameExternal A.sub.n AddressAddressInternal BN, (Burst Address N) AddressAddress Sequencerφ.sub.clock φ.sub.clock signal generation φ.sub.clock sequence: CAS-PAD → CAS1.sub.b → BAEN- → φ.sub.clockSequence (up counting is inherentControl so this control is not required)External AH (address HOLD) AHAddress [functions as externalEnable address latching and disable at same time]Internal BAEN- (Burst Address BAEN -Address Enable- )EnableAddress Out Y.sub.m -L, Y.sub.m L, Y.sub.m -R, Y.sub.m R Address Out (two pairs per single address),(Not Shown) BC.sub.n (Burst Counter CarryOutput) BCN-1 (Burst Counter Carry - Input)______________________________________
Table 2 shows the externally provided input signals/lines for the circuit of FIGS. 5 to 10.
TABLE 2______________________________________EXTERNALLY PROVIDED INPUTSNAME DESCRIPTION______________________________________A.sub.n External addressV.sub.cc powerL left decoder address enableR right decoder address enableYS column address power upAS Address SenseCAS-PAD Column Address Strobe inputMUX- Row - column address multiplexBE/OE Burst enable/output enable inputAH External address enableATDOE Output enable controlWE- Write Enable-WE1 Write Enable______________________________________
Table 3 shows the output signals for the circuit of FIGS. 5 to 10.
TABLE 3______________________________________EXTERNAL OUTPUT SIGNALSNAME DESCRIPTION______________________________________Y.sub.m-L left address bit invertedY.sub.mL left address bitY.sub.m-R right address bit invertedy.sub.mR right address bit______________________________________
Table 4 shows the internal signals for the circuit of FIGS. 5 to 10.
TABLE 4______________________________________NAME DESCRIPTION______________________________________BAEN- Internal address enableBN Internal addressBA.sub.n Internal Start AddressBM Burst modeBC.sub.n Counter carry outputBC.sub.n -1 Counter carry inputPRESET Preset TimingCAS1.sub.b Timingφ.sub.clock φ Clock Timing______________________________________
FIG. 5 corresponds most closely to the block diagram of FIG. 3; however FIG. 5 is for a single address bit and hence shows only one of nine such identical circuits as would be used in FIG. 3. These nine circuits are connected in parallel to provide a nine bit address output signal in this particular exemplary embodiment of the invention.
With reference to FIG. 5, input signal An corresponds to the external Address A n on line 34 in FIG. 3. Signal AH (address hold) functions as the external address latching and disable. This is the external address enable signal, controlling switch 50 in FIG. 5 which corresponds to switch 24 in FIG. 3.
Similarly, the internal address supplied on line 42 of FIG. 3 is designated signal BN in FIG. 5, and is provided as an input to switch 52 corresponding to switch 26 in FIG. 3. Switch 52 is controlled by the internal address enable signal which in FIG. 5 is designated BAEN-. (The inverse of signal BAEN.) It is to be understood that the signal BN is provided from the counter portion of the address generator, described below.
Buffer 22 of FIG. 3 corresponds to the buffer circuitry 56 of FIG. 5. The outputs of the buffer circuitry of FIG. 5 are designated as a "left" and "right" Y (column address) and the inverses thereof (Y m-L , Y mL , Y m-R and Y mR ). (Note there are two decoders, one for the left memory block and the other for the right memory block.) The output of buffer 56 corresponds to one bit of the address out signal of FIG. 3.
The left and right (L, R) signals of FIG. 5 control the buffer 56 outputs, to provide address signals to left or right decoders respectively. Also provided is column address power up signal YS, which disables the input address pass when the chip is in the precharge state. The internal start address output by the circuit of FIG. 5 (designated BA n ) is an input to the associated counter cell, as described below.
FIG. 6 shows the counter (corresponding to the address sequencer 20 of FIG. 3) providing a nine-bit count. The counter has nine identical cells 60-1, 60-2, . . . , 60-9 connected as shown. Each cell has as a first input the internal start address BA n . The second cell input is the carry signal designated BC n-1 from the prior cell. Each cell also receives a first timing signal PRESET, and a second timing signal φ clock . The output of each counter cell is an output address bit BN (which is the address out) which then goes to buffer 56 of FIG. 5, and a second output BC n which is the carry value to the subsequent cell.
It is to be understood that the counter of FIG. 6 occurs only once in the address sequencer 20 and services all nine address buffer circuits, of which only one is shown in FIG. 5.
FIG. 7 shows details of one of the cells of FIG. 6. Signal BC n-1 is the carry input signal, while signal BA n is the external address signal. The timing signals are φ clock and PRESET (and their inverses). The cell output is the "real" address BN and a carry value BC n to the next cell. The cell of FIG. 7 includes conventionally a left-hand side which is the "slave" side 70 and a right hand side which is the "master" side 72 (indicated by the broken line). Thus, there are two latches 70a, 72a one for each side of the counter cell, with one latch at any one time updating its value while the second latch is holding the previously calculated data and transmitting it as output.
FIGS. 8, 9 and 10 show circuitry for generating the timing signals for the serial address generator. The two externally provided timing signals are RAS and CAS-PAD. These in turn generate as shown the internal timing signals. The sequence is that the input clock signal CAS-PAD generates timing signal CAS1 b which in turn generates signal BAEN- which in turn generates signal φ clock . The φ clock signal of FIG. 3 is shown in the timing diagram of FIGS. 11(a), 11(b).
FIG. 8 shows the circuitry which provides the timing signal CAS1 b which is a timing signal for the above-described counter circuitry. Note that signal CAS1 b is in part determined by the signal BM (burst mode) and by the signal WE1 which in this case is the burst write input signal.
FIGS. 11a and 11b show the timing for the signals of FIGS. 5 to 10. The start address (designated A n in FIG. 3) is designated Y N in the timing diagram of FIGS. 11a and 11b. The output signal of the counter is designated Y N+1 , Y N+2 , . . . in the timing diagram. It can be seen that when the clock signal AS goes high, and after a particular period, the PRESET signal goes high. In turn, the PRESET signal going low is determined by the signal CAS-PAD going low.
The overall clock speed of the chip in terms of address generation is determined by the signal CAS-PAD; in one embodiment this signal has a 15 nanosecond period, providing a 66 MHz operating speed.
It is to be understood that in a typical operation of the serial address generator, the associated memory array is considered to be an array of memory cells arranged in rows and columns. Each "page" is one row, with the first address on the page being that of the first memory cell in the column. Signal BE/OE, (burst enable output enable) at the rising edge of AS determines whether one is to be in burst mode or in normal page mode. Signal BE/OE is determined by the host computer. The output of buffer 56 of the circuit of FIG. 5 is connected typically to a column predecoder for determining the particular column of a memory array to be addressed. A predecoder buffers the address signals prior to provision thereof to the decoder itself. The predecoder in this case saves power and increases operating speed, by serving as a buffer for the decoder proper.
The above description is illustrative and not limiting; further modifications will be apparent to one skilled in the art and are intended to be covered by the appended claims.
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A serial address generator for a sequential (burst mode) random access memory generates a sequence of internally generated addresses for fast cycling. The start address is externally provided. Then, as the clock signals arrive, the subsequent addresses are generated in sequence by the address sequencer. The address sequencer is preset to the second address in the sequence following the start address. Simultaneously, the start address is connected by an external address enable switch to an output terminal of the address generator, bypassing the address sequencer. When the first clock signal arrives at the address sequencer, the address sequencer output is sampled by closing an internal address enable switch and opening the external address enable switch. Thus the internally generated addresses are provided immediately following the start address. The address sequencer thereby generates each address one clock cycle ahead of that in the prior art, and the output address is provided one half clock cycle ahead of that in the prior art.
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[0001] This patent application is a divisional application of and claims priority to prior application U.S. Ser. No. 13/142,145, filed on Jun. 28, 2011, incorporated herein in its entirety by reference, which is a national stage entry from PCT/CN2009/00281, which claims priority to Chinese Application No. 2008910189909.0, filed on Dec. 31, 2008 and is incorporated herein in its entirety by reference.
TECHNICAL FIELD OF INVENTION
[0002] The invention relates to a fixed tight joint (hereafter called a sealing joint) of two fixed opposing surfaces disposed at port ends or port shoulders of pressure vessels, pipes or tubes, or pipe or tube fittings to be jointed for holding or conveying fluid medium or power, sod a movable tight joint (hereafter called a closing joint) between movable valving members and valve seat rings for blocking a fluid flow, particularly to a tight joint of any two opposing surfaces one of which has one or two microsawtooth rings and the other of which is fully plain to form a jointing microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing.
TECHNICAL BACKGROUND OF THE INVENTION
[0003] The conveying of fluid medium or power needs to joint a variety of pressure vessels including valves tight by using some pipes or tubes and some pipe or tube fittings to form an enclosed leak-free system. All the fixed tight joints within a pressure vessel and between pressure vessels and pipes or tubes need to be fastened tight, and all the movable tight joints between valving members or discs and valve seats need to be mounted tight; otherwise the controlled transfer of medium or power can not be realized. A fixed or movable tight joint can be made on two parallel flats or two tapered surfaces, on a conical surface to a cone or a sphere, or on a spherical surface to a sphere or a cone; for example, the fixed tight joint of pipe flanges and the movable tight joint of slab gate valves in ISO 14313 are made on two parallel flats, the fixed tight joint between tubes and tube fittings in ISO 8434-2 and the movable tight joint of wedge gate valves in ISO 15761 are made on two tapered surfaces, and the fixed tight joint between tubes and tube fittings in DIN 7601 and the movable tight joint of ball valves in ISO 17292 are made on a conical surface to a sphere. All the fixed tight joints are fastened to be leak free in service, and all the movable tight joints are mounted to be leak free only in stationary closing service and to be movable or not to be leak free for shot-off operations and in stationery open service; i.e. both the fixed tight joint and the movable tight joint are not movable when working as a tight joint, or both are of a static tight joint, and hence the former is especially called a (static) sealing joint or and the latter, a (static) closing joint.
[0004] Any machined metallic surface is microscopically of such irregularities that any tight joint can not be made directly on the originally machined metallic surface, and hence any tight joint in the prior art is made either by seating a soft material into or by lapping to eliminate the irregularities on the two jointing machined surfaces.
[0005] The tight joint made by a soft nonmetallic material, in addition to bearing some new leaking microchannels in the material bulk, bears many troubles such as relaxation or creep, chemical stability or compatibility, contradiction of sealing ability with jointing strength (because the softer the seating material, the stronger the sealing ability but the weaker the jointing strength and vise versa), thermal stability, etc. caused by seating materials, and hence there exist such a greet variety of gaskets of ASME b16.5 Annex C and EN 1514-1˜-8, such a complicated gasket-designing/calculating method of EN 1591, and such complicated gaskets of patents U.S. Pat. Nos. 6,092,811, 6,869,081 and 7,255,353 that it is difficult for an engineer to correctly select a trivial gasket.
[0006] Same ring gaskets in ISO 10423 are used for making a sealing joint of two metal to metal machined flange faces, but only disposable. Some metal to metal valve seats in Patents U.S. Pat. Nos. 4,940,208, 4,502,663, 4,262,688, 4,235,418 and 4,147,327 were to be used for making a closing joint of two sphere to sphere or cone surfaces, but so far no actual products have been found. A V-toothed gasket in EN 1514-6 and an arc-ridged gasket in Patent application WO 94/29620 are used for making a sealing joint of two metal to metal machined flange faces, but the V-teeth and the arc ridges are macroscopic and shall be covered with soft material to avoid metal to metal contacts.
[0007] Obviously, what a simple job it is to design, manufacture, assemble and maintain a tight joint provided directly by two commonly machined surfaces but not by gaskets or lapped surfaces!
SUMMARY OF THE INVENTION
[0008] The object of the invention is to simplify and unify a variety of tight joints of two opposing surfaces, such as flats to flats, conical surfaces to cones or spheres, spherical surfaces to spheres or cones, etc., to avoid both the designing, calculating, manufacturing, selecting, installing and maintaining of fussy gaskets for a tight joint of flat surfaces and the lapping of formed jointing surfaces without using soft gaskets, thus increasing the reliability of tight joints and the utilizing coefficient of natural resources.
[0009] The geometric errors of a machined surface consist of roughness, waviness and form error. The roughness is of the finer microsurface irregularities left by cutting edges; their profile element width (X s ) is narrower, and, to their profile element height (Z t ), is less than 50 (X s /Z t <50). The waviness is of the fine microsurface irregularities caused by vibrations during machining; their profile element width (X s ) is narrow, and, to their profile element height (Z t ), ranges from 50 to 1000 (X s /Z t =50˜1000). The form error is of the wide macrosurface irregularities caused by perpendicular and parallel errors between machine tool ways, spindles and alignment of the workpiece; their profile element width (X s ) is wide, and, to their profile element height (Z t ), is more than 1000 (X s /Z t >1000). The joint surfaces to be sealed are commonly finished by turning or boring operations, which are of a finely machining method and can use an economic high spindle speed resulting in a high frequency vibration and a narrow width of waviness, and use an economic fine feed speed resulting in a fine cut mark and a narrower width of roughness. The form error caused by the clamping or aligning of the workpiece shall and can also be reduced to the ignored extent, whereas the form error caused by machine tool ways and spindles can be of a wave whose cycle or profile element width is too great to be considered within a narrow seating surface; for example, the perpendicularity of transverse guide way and spindle of a lathe at most causes a facing uniformly concave or convex 0.02:500. Therefore, the irregularities for the seating surface to be seated into are of what is caused by the finer profile element width of waviness and roughness on joint surfaces, and clause 5.2 of EN 13555 especially defines what for the seating surface to be seated into to be the irregularities caused by the surface roughness.
[0010] The roughness produced by modern common turning and boring methods can not exceed R a 1.6 μm (see FIG. B1 of ASME B46.1), and hence in order to simplify and unify a variety of tight joints of two opposing surfaces, such as flats to flats, conical surfaces to cones or spheres, spherical surfaces to spheres or cones, etc., the invention especially proposes a sealing joint of two opposing faces disposed at port ends or port shoulders of pressure vessels, pipes or tubes, or pipe or tube fittings to be jointed for holding or conveying fluid medium or power, comprising an opposing face (called a toothed surface) with one or more microsawtooth rings used as seating circles, and the other full plain opposing face (called a plain surface) used as a seated surface, wherein the crest of the microsawtooth ring is a cutting edge whose corner or whose crest angle is about 90°˜120°, the tooth height Z t of the microsawtooth ring is about 10˜20 times the roughness R a of the seated surface or the plain surface, and the ratio of the tooth pitch X s to the tooth height Z t of the microsawtooth ring equals 20˜500 (corresponding to the ratio of the width X s to the height Z t of profile elements between the surface roughness with wider profile elements and the surface waviness with narrower profile elements) to provide for the toothed surface fastened tight on the plain surface a microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing. The sealing microsawtooth ring, having a cutting edge used for providing a line contact whose contact area is approximate to zero and whose contact stress is approximate to infinity, can deform to be seated into the irregularities on the plain surface to make the sealing joint on being pressed thereon by a small jointing pressure (however small it is), and, having an edge-following surface used for protecting the cutting edge from being excessively pressed to get blunt or disappeared on being elastically pressed a little, can therefore always provide an effective line contact for the sealing joint. These microsawtooth rings can he either successively or interruptedly disposed on the toothed surface. Their number does not matter and their orientation can be identical or contrary, but the tooth height Z t determines the deforming measure of the line contact, and the ratio of the tooth pitch X s to the tooth height Z t does the velocity at which the line contact is followed by the surface contact or the extent to which the line contact is provided and protected. In a certain seating surface, the smaller the ratio of the tooth pitch X s to the tooth height Z t , the more the number of the bearing teeth, the slower the velocity at which each line is followed by a surface, and vice versa; using a different number of teeth in a certain seating surface can result in a different velocity for each single tooth, but their total velocity or their total seating effect may not change much or a seal design of more teeth may have the same sealing effect as the one of less teeth to some extent. If the velocity is different at which a line is followed by a surface, the faster the velocity, the larger the seating contact area, the smaller the seating contact stress, and the more decreased the sealing performance, and vice versa. If worn, the more worn the microsawtooth ring, the smoother the joint surface becomes, and the more beneficial to the tight joint.
[0011] In order to add an extra sealing reliability and safety sensation to microsawtooth ring joints, the invention especially proposes a seeing joint of two opposing faces disposed at port ends or port shoulders of pressure vessels, pipes or tubes, or pipe or tube fittings to be jointed for holding or conveying fluid medium or power, comprising an opposing face (called a toothed surface) with one or more microsawtooth rings used as seating circles, the other full plain opposing face (called a plain surface) used as a seated surface, and a gland seal with the gasket groove in the toothed surface or in the plain surface or in the two opposing surfaces and located at the inner or the outer of or between the microsawtooth rings, wherein the microsawtooth ring is mentioned hereinbefore. The volume and the section of gaskets shall match with those of grooves to provide a secondary seal for the joint.
[0012] Similarly, in order to add an extra sealing reliability and safety sensation to microsawtooth ring joints, the invention especially also proposes a sealing joint of two opposing faces disposed at port ends or port shoulders of pressure vessels, pipes or tubes, or pipe or tube fittings to be jointed for holding or conveying fluid medium or power, comprising an opposing face with a centrally raising flat and the other opposing face with a centrally recessing flat to form two opposing flats and an annular groove used as a gland seal when ether the two opposing faces or the two opposing flats are jointed to be a pair of jointing opposing surfaces comprising an opposing surface (called a toothed surface) with one or more microsawtooth rings used as seating circles and the other full plain opposing surface (called a plain surface) used as a seated surface, wherein the microsawtooth ring is mentioned hereinbefore. The volume and the section of gaskets shall match with those of grooves to provide a secondary seal for the joint.
[0013] A typical example for sealing joints of parallel flats is a sealing joint of two opposing flange faces disposed at port ends of pressure vessels, pipes or tubes, or pipe or tube fittings to be jointed for holding or conveying fluid medium or power, either comprising an opposing flange face (called a toothed surface) with one or more microsawtooth rings used as seating circles, and the other full plain opposing flange face (called a plain surface) used as a seated surface, wherein the microsawtooth ring is mentioned hereinbefore; or comprising an opposing flange face (called a teethed surface) with a gasket groove or recess used as a gland seal, and the other full plain opposing flange face (called a plain surface) used as a seated surface, wherein the groove or recess used as a gland seal is mentioned hereinbefore.
[0014] A typical example for closing joints of parallel flats is a closing joint of parallel gate valves which include two seat rings mounted in the valve body and a gate slab or disc slidable therebetween to form a fluid controlling passage or to provide a fully open position when the gate is slid to where a opening portion of the gate slab is aligned with the valve passage or the gate disc is fully off the valve passage and a fully closed position when a blind portion of the gate slab or the gale disc is aligned with the valve passage, comprising a jointing end surface (called a toothed surface) per the seat ring and two parallel jointing surfaces (called plain surfaces) of the gate slab or disc used to form two identical closing joints, wherein there is such one or more microsawtooth rings on each toothed surface pressed tight on each plain surface as to form a jointing microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing, the toothed surfaces are of a full flat or of a raising annular flat and the microsawtooth ring is mentioned hereinbefore.
[0015] A typical example for closing joints of tapered surfaces is a closing joint of wedge gate valves which include two seat rings fixed or integral in the valve body and a wedge disc wedged in or out therebetween to form a fluid controlling passage or to provide a fully open position when the wedge disc is fully off the valve passage and a fully closed position when the wedge disc is wedged tight between the two seat rings, comprising a jointing end surface (called a toothed surface) per the seat ring and two V-shaped jointing surfaces (called plain surfaces) of the wedge disc used to form two identical closing joints, wherein there is such one or more microsawtooth rings on each toothed surface wedged tight on each plain surface as to form a jointing microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing, the toothed surfaces are of a full flat or of a raising annular flat and the microsawtooth ring is mentioned hereinbefore.
[0016] A typical example for closing joints of spheres to conical or spherical surfaces is a closing joint of ball valves which include two seat rings mounted in the valve body and a ball turnable therebetween to form a fluid controlling passage or to provide a fully open position when the ball is turned to where the central through opening of the ball is coaxial with the valve passage and a fully closed position when the ball is turned to where the central through opening of the ball is perpendicular to the valve passage, comprising a jointing conical surface (called a toothed surface) per the seat ring and the jointing sphere (called a plain surface) of the ball used to form two identical closing joints, wherein there is such two microsawtooth rings on each toothed surface pressed tight on the plain surface as to form a jointing microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing. These two microsawtooth rings are developed in the original conical surface of the toothed surface by undercutting out another cut of conical surfaces symmetrically arranged about the ball's center and parallel to the original conical surface and having a radial distance Z t away from the plain surface passing through the vertexes of the two microsawtooth rings, which means the height of the two microsawtooth rings is Z t relative to the plain surface; the crest of the microsawtooth ring is a cutting edge whose corner or whose crest angle is about 90°˜120°, and the tooth height Z t of the microsawtooth ring is about 10˜20 times the roughness R a of the seated surface or the plain surface to provide for the toothed surface fastened tight on the plain surface a microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing. Actually, the distance between the original and the undercut conical surfaces is visible or macroscopic, not the tooth height Z t of the microsawtooth ring that is the distance between the undercut conical surface and the jointing sphere.
[0017] It has been clear from the above-mentioned examples that the microsawtooth ring of the invention can be used in the tight joint of a variety of machined surfaces such as flats to flats, conical surfaces to cones or spheres, spherical surfaces to spheres or cones, etc. As a matter of fact, a tight joint of any machined surfaces can be made by microsawtooth rings whose tooth height is somewhat greater than the height of profile elements of waviness (caused by cut vibrations) and roughness (caused by cutting edges), as long as the height of form error profile waves caused by perpendicularity and parallelism between machine tool ways, spindles and alignment of the workpiece is smaller than the height of waviness and roughness profile waves within the raising jointing surface with microsawtooth rings. For example, any closing joint of globe valves, check valves, etc. and any sealing joint of two opposing faces of split valve bodies, between engine cylinders and their heads, etc., which are not enumerated above and do not relate to any perpendicularity between the jointing face and its fastening thread, can be made by microsawtooth rings; and so can be any sealing joint of two opposing faces relating to their perpendicularity to their fastening threads, as long as the face and its fastening thread are developed in one clamping operation.
[0018] Any sealing process is for a seating surface or material to be seated into irregularities of a seated surface of two joint surfaces, and hence the rougher the seated surface, the more difficult it is to make the sealing joint, or the smoother the seated surface, the easier it is to make the sealing joint. However, the tight joint relying on gaskets of the prior art has not allowed a seated surface to be too smooth, for the gasket will be blown out by pressure from between the too smooth seated surfaces when relaxed. Accordingly, ASME B16.5 specifies that flange facings shall be the one with a serrated concentric or serrated spiral finish having a resultant surface roughness from R a 3.2 μm to 6.3 μm average roughness. Such a turning and boring surface roughness is a machining finish at the beginning of industrialization, only equivalent to the preliminary working level of modern industries; the modern common turning and boring level is surface roughness R a 1.6 μm to R a 3.2 μm for interior surfaces, and R a 0.8 μm to R a 1.6 μm for exterior surfaces (see FIG. B1 of ASME B46.1); and hence it can be said that the sealing art of gaskets parallel to a rough machining means at the beginning of industrialization is so incompatible with the modern machining art as to prolong either the service life of rough cutting machines to be obsoleted with high energy consumption or the working time of sophisticated machines in rough cutting operations, which accompanies both the meaningless consuming of natural resources and the numerous trashing of used gaskets to pollute the environment because gaskets can not be reused. Therefore, it can be said that the sealing art using the microsawtooth ring of the invention is a major technical progress keeping pace with times because the microsawtooth ring can only be economically developed by modern numerically controlled technology.
[0019] ASME Boiler & Pressure Vessel Code—Section VIII—Division 1—Appendix 2 (hereafter called ASME Code) proposes two gasket facto m and y used to calculate loads of gasketed flanges and adopted by EN 13445; y is the minimum necessary seating stress on the gasket to provide a seal at atmospheric temperature and pressure or at no fluid pressure, determined by testing at a fluid pressure of 0.14 bars, and m=(W−A 2 P)/A 1 P is a factor that provides an additional preload needed in the flange fasteners to maintain a compressive load on the gasket at a fluid pressure, where W is the total fastener force, A 2 is the inside area of the gasket (equivalent to the actuating area of fluid on the flange cover), A 1 is the seating area of the gasket, and P is the field pressure. Undoubtedly, the force (W−A 2 P) is what to be able to result in a sealing stress on the seating surface at a fluid pressure P, whereas the force A 1 P is what to be able to cause an unseating force on the seating surface of the gasket by leaking fluid at a fluid pressure P; i.e. the factor m, for any tight joint, is the ratio of the force capable of resulting in a sealing stress on the seating surface of the joint to the unseating force of leaking fluid on the seating surface of the joint, and for a self-energizing tight joint, the ratio of the self-energizing force of the joint to the unseating force of leaking fluid on the seating surface of the joint, as well as for a pressure-tight joint (non-self-energizing), the ratio of the sealing force created by fasteners to the unseating force of leaking fluid on the seating surface of the joint. Obviously, the magnitude of the factor m should have been no direct thing to do with the factor y, and the greater the value of m, the more reliable the tight joint. However, it seems that ASME Code has not yet found the implied seal-designing law because major values of m and y in the present release of ASME Code are still determined by the equation: 180·(2m−1) 2 =y, but has found some problems of the equation because minor values of m and y in the present release have not been in accordance with the equation. As ASME Code does not relate the gasket factors m and y to the leak rate, the PVRC (Pressure Vessel Research Council) and EN 13555 respectively propose new gasket constants or parameters related to tightness or leak rate and substituted for the gasket factors m and y, thus the gasket design becoming more complicated. However, the new PVRC's test method has been advanced to ASTM WK 10193-2006 but has not come into force for decades, and EN 13445 adopting the gasket factors m and y has not yet be superseded by EN 13555 coming into force in 2004. It seems that these newly specified constants or parameters may still have something wrong.
[0020] The gasket factors m and y in ASME Code are based on looking at if a joint is leaky or not; the gasket constants in PVRC's fast method, based on quantitative looking at the tightness of a joint for each internal pressure; and the gasket parameters in EN 13555, based on quantitative looking at the leak rate of a joint for a given internal pressure. According to ASME Code's concept, the minimum necessary seating stress of a gasket is a function of the gasket material strength and the seated surface texture, being a factor having nothing to do with the fluid pressure and the seating area for a given material and a given seated surface. According to PVRC's and EN's concepts, the minimum necessary seating stress of a gasket is related to the fluid pressure in addition to the gasket material strength and the seated surface texture, because the leak rate is related to leaking microchannels in the material bulk and will increase with the field pressure. Namely, the minimum necessary seating stress of a gasket is the force per unit seating area of the gasket, which is a parameter not related to the magnitude of the seating area, for a given material and a given seated surface, according to either the ASME Code's concept or the PVRC's and EN's concept. However, the minimum necessary seating stress for closing joints in some Chinese practical manuals for valve designs is related to no leak rate but to both fluid pressures and seating areas, which is not in accordance with either the ASME Code's concept or the PVRC's and EN's concept.
[0021] Each technical solution of the invention is based on correcting or improving and extending ASME Code's original concept for the gasketed flanges:
[0022] The invention defines the fixed tight joint of flanges fastened by threads or bolts as a fixed static tight joint, and does the movable closing joint of valves as a movable static tight joint. Thus the gasket factors m and y used for designing a tight joint of flanges in ASME Code are refined and extendedly used for designing a closing joint of valves. As a matter of fact, the extension is scientific because the difference between the two static tight joints is only their jointing frequency.
[0023] The invention extendedly defines the implied scientific meaning of ASME Code's gasket factor m as an explicit sealing maintenance factor or disturbance resistance index m (equal to the force capable of resulting in a sealing stress on the seating surface divided by the unseating force of leaking field on the seating surface) of a tight joint, and regards the seating surface as an upset impulse amplifier, thus proposing using the factor m to survey and design each tight joint in the light of ensuring it a higher value of m and thus a higher sealing reliability. In fact, any seating surface of tight joints is a real upset impulse amplifier and may output an unseating force not exceeding “seating area×fluid pressure” only with or under an upset impulse disturbance because the fluid will speedily seep into the seating surface in such a way from a partial to the whole surface as to cause a greater and greater unseating force finally up to five maximum of “seating area×fluid pressure” only when a tight joint is disturbed to an extent causing an enough decrease of seating stress, and of course, the greater the ratio of the force capable of resulting in a sealing stress on the seating surface to the unseating force of leaking fluid on the seating surface of the joint, or the greater the value of m of a tight joint, the higher the sealing reliability of the joint and the lower the leak rate of the joint. Therefore, it is undoubted that the sealing maintenance factor or disturbance resistance index m newly defined by the invention accords with the objective reality and reveals an universal law of tight joints; as to a self-energizing tight joint, its sealing and unseating forces are both created by a fluid pressure and hence undoubtedly the value of its m equals its fluid's sealing actuation area divided by its fluid's unseating actuation area; and as to a pressure-tight joint, its sealing force on the seating surface is created by fasteners and hence obviously its value of m equals its fastener-created sealing force divided by its fluid-caused unseating force on the seating surface.
[0024] The invention, based on the ASME Code's implication that a lower minimum necessary seating stress will be more desirable for tight joints, proposes a microsawtooth ring disposed on the jointing surface and used to provide for a tight joint a line contact followed by a surface contact protecting the line contact thereon from being crushed in reassemblies, thus making the tight joint at first have a line contact with its seating area approximate to zero or have a real seating stress satisfying its initial seating and approximate to infinity under a small fastening force, and then have a surface contact with such a small minimum necessary seating stress as to be virtually ignorable for load calculations and that the designing of tight joints only needs to consider a sealing maintenance factor m equivalent to the safety factor n to be considered when designing a general mechanical device.
[0025] As the sealing maintenance factor m of a self-energizing tight joint equate its fluid's sealing actuation area divided by its fluid's unseating actuation area, if can be said that its factor m is its inherent parameter, only related to its magnitudes of two fluid's actuation areas but not related to its material strength and its seated surface texture or not related to its minimum necessary seating stress y at atmospheric temperature and pressure, and its magnitude of m can be changed by changing its design and size, or not a fixed value of zero specified in ASME Code. For example, the value of the sealing maintenance factor m of an O-ring seal is not zero and changeable with its gland design or can be changed by clanging its gland dimensions or by changing its ratio of two fluid's sealing and unseating actuation areas to obtain an adequate sealing reliability. As to the ball valve seats of patent CN 20081017828.X, whatever they are made of, the value of the sealing maintenance factor m of the ball valve seat in FIG. 7 a is changeable with its design, where the closing joint is made by having the ball 03 self floated on the valve seat 02 ; the value of the factor m of the ball valve seat in FIG. 10 is equal to one, where the closing joint is made by having the valve seat 02 a and 02 b self-floated on the ball 03 ; and the value of the factor m of the ball valve seat in FIGS. 11 a and 11 b is equal to 1.41, where the closing joint is made by having the valve seat 02 a and 02 c self floated on the ball 03 .
[0026] As the sealing maintenance factor m of a pressure-tight joint equals its fastener-created sealing force divided by its fluid-caused unseating force on its seating surface, it can be said that its factor m is only related to its magnitudes of the fastening force resulting in a sealing effect and the unseating force caused by leaking fluid, but not related to its material strength and its seated surface texture, or not related to its minimum necessary seating stress y at atmospheric temperature and pressure, and its magnitudes of m can be changed within the material's allowable strength by changing its design and size to obtain an adequate sealing reliability. However, ASME Code incorrectly relates the gasket factor m to the gasket factor y by an equation of 180·(2m−1) 2 =y.
[0027] As a microsawtooth ring joint always begins with a line contact having an initial seating area more approximate to zero or having an initial seating edge sharper to be more easily seated into the irregularities when made by a harder material, and having a quality easier to be seated into the irregularities when made by a softer material, it can be said that any tight joint made by an adequate microsawtooth ring, however hard or soft its material is, will only need such a small minimum necessary seating load as to be ignorable for load calculations. Besides, the pre-fastening force not resulting in any sealing stress at ultimate working pressures, such as at a test pressure equal to four times the rating pressure, can provide an initial seating stress far greater than the needed at atmosphere temperature and pressure, and hence it can be imagined that any tight joint made by an adequate microsawtooth ring only needs a share and also can be easily provided with the share of additional forces required to maintain and enhance the small to be ignorable initial seating load and equal to m times its fluid's unseating actuation force; moreover the greater the value of its factor m, the higher its sealing reliability and the lower its leak rate. When me joint's factor m of a tight joint is equal to one, the joint's sealing actuation force equate the joint's unseating actuation force, and so the tight joint will get into a leaky or leak-free critical state; i.e. any tight joint shall have a sealing maintenance factor m with its value more than one and can be in a stable leakfree state as the value is slightly more than one. However, in the light of ASME Code's incorrect concept, the critical value of the factor m of a tight joint that gets leaky or leak-free seems 0˜6.5 and changes with its material and surface texture.
[0028] From the above-mentioned, it can be seen that the “joint's sealing maintenance factor or disturbance resistance index m (=joint's sealing actuation force divided by joint's unseating actuation force)” defined in the invention has been mostly different in concepts and applications from the ASME Code's gasket factor m, although refined from the ASME Code's. It might have been very easy for some persons skilled in the art to make a careful study of ASME Code's gasket factors and to be able to find that the gasket factor m has no direct thing to do with the gasket factor y, but no one has not been confined to ASME Code and has reached the great seal-designing law implied in the ASME Code's gasket factors m and y.
[0029] Therefore, the invention is a dig of and a breakthrough in the prior gasket factor's concept in ASME Code, and the breakthrough originates at the time when it is fully understood that the joint's minimum necessary seating stress y with a small to be ignorable value is the necessary and sufficient condition for the concept or the equation of the joint's seating maintenance factor m at a fluid pressure to be significant or tenable universally, although the magnitudes of the two factors have no direct thing to do with each other. In fact, only when lowering the joint's factor y to an ignorable level or only when using a seating unit whose minimum necessary seating stress y is enough small, can a safe initial tight joint be earlier fully ensured, a smaller sealing actuation force get more effective for the joint, the joint be called a tight joint, and there be a tight joint needed to be maintained or there exist a sealing maintenance factor m virtually significant or tenable for the tight joint. Thus it can be said that the invention is at first creating a microsawtooth ring used as the seating unit of a tight joint to mate its factor y ignorable, and then using the microsawtooth ring and the concept of the joint's factor m to create some tight joints with excellent sealing performance and to achieve the object of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] All the microsawtooth rings in the drawings of the invention are showed in an exaggerated way, where Z t stands for their tooth height, and X s , for their tooth pitch.
[0031] FIG. 1 shows a pair of bolted non-gasketed flanges in accordance with the invention, where flange A is the flange with a designed or toothed facing or with four sealing microsawtooth rings and one peripheral supporting macrosawtooth ring on its facing, and flange B is the flange with a full flat facing. When the two toothed and full flat facings are fastened tight together by bolts, the microsawtooth rings are used as seating circles to make a tight joint, and the macrosawtooth ring are used as a fastening support at first to ensure the tight joint a circumferentially uniform seating contact and then to prevent the flange rotation.
[0032] FIG. 2 shows two design pairs of bolted gasketed flanges in accordance with the invention, where the left and right sections each represent a design pair. The left section indicates a design pair of flanges with an integral groove of gland seals, where flange A is the flange with a designed or toothed facing or with two sealing microsawtooth rings, one peripheral supporting macrosawtooth ring and one gasket groove on its facing, and flange B is the flange with a full flat facing; when the two toothed and full flat facings are fastened tight together by bolts, the microsawtooth rings are used as seating circles to make a tight joint (the first tight joint), the gasket 04 a in the groove is used to make a self-energizing tight joint (the second tight joint), and the macrosawtooth ring are used as a fastening support at first to ensure the two tight joints a circumferentially uniform seating contact and then to prevent the flange rotation. The right section indicates the other design pair of flanges with an assembled groove of gland seals, where flange A is a flange with a centrally raised facing whose centrally raising flat is full plain and whose peripherally lowering flat has two sealing microsawtooth rings and one peripheral supporting macrosawtooth ring, and flange B is a flange with a centrally recessed facing whose centrally recessing flat and whose peripherally raising flat are full plain; when the two stepped facings are fastened tight together by bolts, from the inner to the outer are in turn formed a pair of opposing flats without close contact to be free of joint's interference, an annular groove used to make a self-energizing tight joint (the second tight joint) by a round or rectangular gasket 04 b therein, a pair of opposing flats with close contact used to make a tight joint (the first tight joint) by the microsawtooth rings, and a macrosawtooth ring support used to at first to ensure the two tight joints a circumferentially uniform seating contact and then to prevent the flange rotation.
[0033] FIGS. 3 a ˜ 3 c are the enlarged views of local area II a in FIG. 2 . The rectangular gasket 04 a in FIG. 3 a, with a more height compression, will get bulged in the middle after installed, and in FIG. 3 b, with a less height compression, will have no substantial deformation after installed. FIG. 3 d is the enlarged view of local area II b in FIG. 2 , where the gasket 04 b is of a round section.
[0034] FIG. 4 shows a slab gate valve whose closing joint, as shown in FIG. 5 (the enlarged view of the local area III of FIG. 4 ), is made by the microsawtooth ring in accordance with the invention, and whose sealing joints for two flanged ends A and whose sealing joint of body A and bonnet B not shown as in FIG. 6 are the same as the sealing joint of flanges in the left section of FIG. 2 .
[0035] FIG. 6 shows a wedge gate valve whose closing joint, as shown in FIG. 7 (the enlarged view of the local area IV), is made by the microsawtooth ring in accordance with the invention, and whose sealing joints for two flanged ends A and whose sealing joint of body A and bonnet B are the same as the sealing joint of flanges in the left section of FIG. 2 .
[0036] FIG. 8 shows a floating ball valve whose closing joint as shown in FIG. 9 (the enlarged view of the local area V), is made by the microsawtooth ring in accordance with the invention, and whose sealing joint of split bodies, as shown in FIG. 10 (the enlarged view of the local area VI), is the same as the sealing joint of flanges in the left section of FIG. 2 .
[0037] What FIGS. 11 a , 11 b , 12 a and 12 b show are four typical gland seals used in the invention. The gasket groove ( 1 - 2 - 3 - 4 ) of FIGS. 11 a and 11 b is of a square section, and the path leaking from L i →L o is at first along route 1 - 4 - 3 or of a curve leak type. The gasket groove ( 1 - 2 - 3 - 4 ) of FIGS. 12 a and 12 b is of a rectangular section, and the path leaking from L i to L o is along route 1 - 2 or of a straight leak type. The gaskets of FIGS. 11 a and 12 a are crammed tight in their grooves and have no fluid actuation area and no self-energizing ability, whereas the gaskets of FIGS. 11 b and 12 b are not crammed to the pressurized wall of their grooves and have some fluid actuation area and some self-energizing ability.
DETAILED DESCRIPTION OF THE INVENTION
[0038] According to the invention, the tight joints of a variety of machined surfaces such as flats to flats, conical surfaces to cones or spheres, spherical surfaces to spheres or cones, etc. can be made by microsawtooth rings; in order to add an extra sealing reliability and safety sensation to microsawtooth ring joints, a gland seal can be added to the inner side or the outer side of or between the microsawtooth rings to provide for the joint a tight joint by microsawtooth rings and another tight joint by gland seals; and the additional gland seals can be summarized as a curve leak type and a straight leak type, and provided with a non-self-energizing or self-energizing gasket.
[0039] FIG. 1 shows a sealing joint of two flanges made by the microsawtooth ring in accordance with the invention, where flange A is the flange with a designed or toothed facing or with four sealing microsawtooth rings and one peripheral supporting macrosawtooth ring on its facing, and flange B is the flange with a full flat facing. The two toothed and full flat facings, fastened tight together by bolts, are provided with a tight joint made by the microsawtooth rings used as seating circles, and provided with a fastening support made by the macrosawtooth ring used at first to ensure the tight joint a circumferentially uniform seating contact and then to prevent the flange rotation.
[0040] FIG. 2 shows two sealing joints of flanges made by the microsawtooth ring and the additional gland seal in accordance with the invention; the left section indicates a sealing joint of flanges with an integral groove of gland seals, and the right section indicates the other sealing joint of flanges with an assembled groove of gland seals. The left flange A is the flange with a designed or toothed facing or with two sealing microsawtooth rings, one peripheral supporting macrosawtooth ring and one integral gasket groove on its facing, and the left flange B is the flange with a full flat facing; the two toothed and full flat facings, fastened tight together by bolts, are provided with a tight joint (the first tight joint) made by the microsawtooth rings used as seating circles, provided with another self-energizing tight joint (the second tight joint) made by the gasket 04 a in the groove, and provided with a fastening support made by the macrosawtooth ring used at first to ensure the tight joint a circumferentially uniform seating contact and then to prevent the flange rotation. The right flange A is a flange with a centrally raised facing whose centrally raising flat is full plain and whose peripherally lowering flat has two sealing microsawtooth rings and one peripheral supporting microsawtooth ring, and the right flange B is a flange with a centrally recessed facing whose centrally recessing flat and whose peripherally raising flat are full plain; the two stepped facings, fastened tight together by bolts, are from the inner to the outer in turn provided with a pair of opposing flats without close contact to be free of joint's interference, an annular groove used to make a self-energizing tight joint (the second tight joint) by a round or rectangular gasket 04 b therein, a pair of opposing flats with close contact used to make a tight joint (the first tight joint) by the microsawtooth rings, and a macrosawtooth ring support used to at first to ensure the two tight joints a circumferentially uniform seating contact and then to prevent the flange rotation. The sealing joints of valve seat 02 a and valve body 01 in FIGS. 4 (or 5 ) and 8 (or 9 ) are also the sealing joint made by the microsawtooth and the additional gland seal in FIG. 2 .
[0041] As the peripheral supporting macrosawtooth ring in FIGS. 1 and 2 is of a high microedge and can also be partially provided only near bolts if necessary, the macrosawtooth ring generally can have such a strength far lower than the sealing microsawtooth rings with a low microedge but be virtually of such a strong fastening support for every tightening operation in each torque-increased tightening round of cross-tightening sequences as not to influence the microsawtooth ring to be seated into irregularities and make a tight joint but also avoid an asymmetric load of bores and a flange rotation of traditional joints.
[0042] The left gland seal in FIG. 2 is of a straight leak type, whose leaking path is along the jointing surface between gasket 04 a and flange B; whereas the right gland seal in FIG. 2 is of a curve leak type, whose leaking path is at first along the jointing curve surface between gasket 04 b and flange B. If crammed tight in its groove after the joint is made, the gasket will have no fluid actuation area or have no self-energizing ability to enhance the tight joint, whose seating load or stress can only be pre-provided by the fasteners during assembling. If not crammed to the pressurized wall of its groove after the joint is made, the gasket will have fluid actuation area or have self-energizing ability to enhance the tight joint, whose seating stress will increase with the fluid pressure. The gaskets 04 a and 04 b shown in FIG. 2 is deployed to make self-energizing tight joints.
[0043] The original self-energizing gasket 04 a in FIG. 2 can be either of a rectangular section shown in FIGS. 3 a and 3 b or of a round section shown in FIG. 3 c, whose section and volume shall be helpful in having a close contact with the other sides except the high pressure side of its groove after the joint is made in order to enable the fluid 07 on it to create a sealing force; the gasket in FIG. 3 a, with a more height compression, will get bulged in the middle after installed; whereas the gasket in FIG. 3 b, with a less height compression, may be still nearly rectangular after installed.
[0044] As shown in FIGS. 3 a ˜ 3 c, the left self-energizing gasket 04 a in FIG. 2 has a fluid's sealing actuation area equal to πDka, a fluid's unseating actuation area equal to π·(D+a)·a, and a ratio of “fluid's sealing actuation area to fluid's unseating actuation area” equal to k/(1+a/D); and therefore only when k>(1+a/D), could it ensure a tight joint by a soft gasket with such an enough liquid behavior or with such a Poisson's ratio approximate to 0.5 as to fully change the pressure on its fluid's sealing actuation surface into the seating stress on its seating surface, and perhaps only when k>2(1+a/D), by a hard gasket without such an enough liquid behavior or without such a Poisson's ratio approximate to 0.5 as to at most half change the pressure on its fluid's sealing actuation surface into the seating stress on its seating surface. If of a round section as shown in FIG. 3 c, the left self-energizing gasket 04 a in FIG. 2 shall still have k<4/π because it will have a section diameter equal to or smaller than its groove depth so as to have no height squeeze or no initial seating contact or no self-energizing ability when k≧4/π (see patent CN 101551013A); i.e. the value of k for a round section of gasket 04 a in FIG. 2 shall satisfy the inequality: (1+a/D)<k<4/π. Thus it can be seen that a rectangular gasket, when used for a straight leak type of self-energizing gland seals, only has a minimum limit of k and so is more easily designed to have a higher sealing reliability than a round gasket with two limits of k.
[0045] As shown in FIG. 3 d, the right original self-energizing gasket 04 b in FIG. 2 should have an adequate round section and a square groove in order to have a contact length a′ and an avoidance or contactless chord length k′a′ in the section between the gasket and the groove and to make k′>√{square root over ( 2 )} after installed. When k′>√{square root over ( 2 )}, the sealing maintenance factor m at the four lengths a′ of soft gaskets with an enough liquid behavior will be nearly more than √{square root over ( 2 )}, and at least at the two lengths a′ close to the leaking exit of hard gaskets without an enough liquid behavior, always more than 1. Thus it can be seen that the round gasket has an excellent sealing performance when used for a curve leak type of self-energizing gland seals.
[0046] FIG. 4 shows a slab gate valve whose closing joint is made by the microsawtooth ring in accordance with the invention, including two seat rings 02 a mounted in the valve body 01 and a rectangular gate slab 03 slid up and down therebetween by operating a valve stem to control the fluid flow. As shown in FIG. 5 (the enlarged view of the local area III of FIG. 4 ), there is respectively a microsawtooth ring concentric with the fluid passage on each jointing end surface between the seat rings 02 a and the gate slab 03 and on each jointing end surface between the valve body 01 and the seat ring 02 a, and there is a gasket 02 b between the valve body 01 and the seat ring 02 a. When slid to where its opening and the fluid passage are fully staggered, the gate slab 03 will be in turn pressed by the fluid tight on the downstream seat ring 02 a, the gasket 02 b and the valve body 01 to make a tight joint on the downstream seat ring by the microsawtooth ring and to make a dually tight joint between the seat ring 02 a and the valve body 01 by the gasket and the microsawtooth ring. The two jointing surfaces of the gate slab 03 can be either a full flat or an annular spot facing. The gaskets 02 b can be either of the left pressure-tight rectangular section or of the right self-energizing round section. The tight joint of the valve bonnet and body not shown in FIG. 4 can be made by the microsawtooth ring and the additional gland seal as shown in FIG. 6 .
[0047] FIG. 6 shows a wedge gate valve whose closing joint is made by the microsawtooth ring in accordance with the invention, including two seat rings integral in the valve body 01 and a wedge disc 03 wedged in and cut therebetween by operating a valve stern 06 to control the fluid flow. As shown in FIG. 7 (the enlarged view of the local area IV of FIG. 6 ), there is a microsawtooth ring nearly concentric with the fluid passage on each jointing end surface of the seat rings and the wedge disc 03 . When wedged tight between the two seat rings, the wedge disc 03 may be further pressed by the fluid tight on the downstream seat ring to maintain a tight joint thereon by the microsawtooth ring. The two jointing surfaces of the wedge disc 03 can be either a full flat or an annular spot facing. The seat rings can be integrated tight in the valve body 01 by embedding. The tight joint of the valve bonnet 05 and the valve body 01 can also be made by the microsawtooth ring and the additional gland seal as shown in FIG. 6 , where the valve body end A and the bonnet end B are respectively the same in designs as the left flanges A and B of FIG. 2 .
[0048] FIG. 8 shows a floating ball valve whose closing joint is made by the microsawtooth ring in accordance with the invention, including two seat rings 02 a mounted in the valve body 01 and an on-off ball 03 turned therebetween by operating a valve stem 06 to control the fluid flow. As shown in FIG. 9 (the enlarged view of the local area V of FIG. 8 ), there are respectively two microsawtooth rings on each jointing conical surface AB of the seat rings 02 a and the ball 03 and on each jointing end surface between the valve body 01 and the seat ring 02 a, and there is a gasket 02 b between the valve body 01 and the seat ring 02 a . When turned to where its central through opening is perpendicular to the fluid passage, the ball 03 will be in turn pressed by the fluid tight on the downstream seat ring 02 a , the gasket 02 b and the valve body 01 to make a tight joint on the downstream seat ring by the microsawtooth rings a′ and b′ and to make a dually tight joint between the seat ring 02 a and the valve body 01 by the gasket 02 b and the microsawtooth rings either on the seat ring 02 a or on the valve body 01 . The microsawtooth rings a′ and b′ are developed on the original conical surface AB by undercutting out another cut of conical surfaces a″b″ symmetrically arranged about the ball's center and parallel to the original conical surface AB and having a radial distance Z t away from the ball's surface passing through the vortexes of the two microsawtooth rings a′ and b′, which means the height of the two microsawtooth rings a′ and b′ is only Z t relative to the jointing ball's surface; the crest of the microsawtooth ring a′ and b′ is a cutting edge whose corner or whose crest angle is about 90˜120°, and the tooth height Z t of the microsawtooth rings a′ and b′ is about 10˜20 times the roughness R a of the ball's surface to provide for the conical surface AB fastened tight on the ball's surface a microcosmic line contact followed by a surface contact protecting the line contact thereon from disappearing. Actually, the distance between the original conical surface AB and the undercut conical surface a″b″ is visible or macroscopic, not the tooth height Z t of the microsawtooth rings a′ and b′ relative to its jointing ball's surface, the microcosmic Z t being the distance between the undercut conical surface a″b″ and the jointing ball's surface. As shown in FIG. 10 (the enlarged view of the local area VI of FIG. 8 ), the tight joint of the valve cover 05 and the valve body 01 can also be made by the microsawtooth ring and the additional gland seal ( 04 ), where the valve body end and the valve cover are respectively the same in sealing designs as the left flanges A and 8 of FIG. 2 , merely different in fastening ways that here is directly by threads and there is by bolts, and can be of a tight joint of flanges in a broad sense.
[0049] All in all, the sealing joint of bolted non-gasketed flanges in FIG. 1 , the sealing joint of bolted gasketed flanges in FIG. 2 , the closing joint of slab gate valves in FIG. 4 , and the sealing joints for the flanged ends A and between the valve body 01 and the valve bonnet or cover 05 in FIGS. 4 , 6 and 8 are some embodiments of the tight joint of two flat surfaces made by microsawtooth rings; the closing joint of wedge gate valves in FIG. 6 can be regarded as an embodiment of the tight joint of two tapers or cones made by microsawtooth rings; and the closing joint of floating ball valves in FIG. 8 can be regarded as an embodiment of the tight joint of two spherical to conical surfaces made by microsawtooth rings. As shown in the local enlarged views, the crest of all the microsawtooth rings is a cutting edge whose corner or whose crest angle is about 90°˜120°, the tooth height Z t is about 10˜20 times the roughness R a of the seated surface, and the ratio of the tooth pitch X s to the tooth height Z t equals 20˜500 (corresponding to the ratio of the width X s to the height Z t of profile elements between the surface roughness with wider profile elements and the surface waviness with narrower profile elements). These microsawtooth rings can be ether successively or interruptedly disposed on the seating surface. Their number does not matter and their orientation can be identical or contrary, but the tooth height Z t determines the deforming measure of the line contact, and the ratio of the tooth pitch X s to the tooth height Z t does the velocity at which the line contact is followed by the surface contact or the extent to which the line contact is provided and protected. In a certain seating surface, the smaller the ratio of the tooth pitch X s to the tooth height Z t , the more the number of the bearing teeth, the slower the velocity at which each line is followed by a surface, and vice versa; using a different number of teeth in a certain seating surface can result in a different velocity for each single tooth, but their total velocity or their total seating effect may not change much and may still ensure the tight joint a microcosmic line contact followed by a surface contact. The line contact, having a seating area approximate to zero and so a seating stress approximate to infinity, can always deform to be seated into the irregularities on the seated surface to make a sealing joint on being pressed thereon by a small jointing pressure (however small it is), and, followed by the whole seating surface protecting it from being excessively pressed to get blunt or disappeared on being elastically pressed a little, can also always keep it effective for ever for the sealing joint. If the velocity is different at which a line is followed by a surface, the faster the velocity, the larger the seating area, the smaller the seating stress, and the more decreased the sealing performance, and vice versa.
[0050] What FIGS. 11 a, 11 b , 12 a and 12 b show are four typical gland seals used in the invention. The gland seal shown in FIGS 11 a and 11 b is of a curve leak type, whose gasket groove is of a square section 1 - 2 - 3 - 4 and whose path leaking from L i →L o is at first along route 1 - 4 - 3 and then along route 1 - 2 - 3 because the areas and the stresses of surfaces 1 - 4 and 2 - 3 are equal to each other, and the area and the stress of surface 3 - 4 , respectively greater and smaller than surface 1 - 2 . The gland seal shown in FIGS. 12 a and 12 b is of a straight leak type, whose gasket groove is of a rectangular section 1 - 2 - 3 - 4 and whose path leaking from L i →L o is along route 1 - 2 . However, the gaskets of FIGS. 11 a and 12 a are crammed tight in their grooves and have no fluid actuation area and no self-energizing ability, whereas the gaskets of FIGS. 11 b and 12 b are not crammed to the pressurized wall of their grooves and have some fluid actuation area and some self-energizing ability. Actually, these four gland seals are also the typical designs of the general gland seals. It is adequate to select a self-energizing tight joint for use with a soft gasket, such as a rubber gasket, having such an enough liquid behavior or having such a Poisson's ratio approximate to 0.5 as to fully change the pressure on its fluid's sealing actuation surface into the seating stress on its seating surface, and having such an incompressibility in volume and such a unrecoverable compression set in dimensions as to make use of them to enhance the tight joint; to select a pressure-tight joint for use with a flexible graphite gasket having such a compressible volume as to harmoniously pre-eliminate the leaking microchannels in each directional material bulk by preloading; and to respectively select such a rectangular gasket as shown in FIG. 12 b and such a round gasket as shown in FIG. 11 b for use with a straight leak type and a curve leak type of self-energizing gland seals as to have a higher value of sealing maintenance factor or disturbance resistance index m (see the above descriptions on the designs of FIG. 3 ).
[0051] The assembled groove type of gland seals used with a microsawtooth ring joint can be either of a pressure-tight seal shown in FIG. 11 a or of a self-energizing seal shown in FIG. 11 b , and the integral groove type of gland seals used with a microsawtooth ring joint can be either of a pressure-tight seal shown in FIG. 12 a or of a self-energizing seal shown in FIG. 12 b.
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A sealing microsawtooth ring joint, made between a toothed seating surface and a full plain seated surface by a microsawtooth ring with its tooth crest on the seating surface being a cutting edge whose corner or whose crest angle is about 90°˜120°, with its tooth height Z t being about 10˜20 times the roughness R a of the seated surface, and with the ratio of its tooth pitch X s to its tooth height Z t being 20˜500 to ensure that the tight joint has a microcosmic line contact followed by a surface contact or to ensure that the tight joint has both such a line contact as to be able to provide a necessary seating stress locally and such a surface contact as to be able to protect the line contact from being excessively pressed to get blunt or disappeared, can be used either as a pressure-tight joint or as a self-energizing tight joint of any too surfaces such as flats to flats, cones to cones or spheres, spheres to spheres or cones etc., thus simplifying and unifying the designing, calculating, manufacturing, selecting, installing and maintaining of fussy gaskets for a tight joint of flat surfaces, avoiding the lapping of formed jointing surfaces without using soft gaskets, increasing the reliability of tight joints sod the utilizing coefficient of natural resources. The sealing microsawtooth ring joint can still have an extra sealing reliability and safety sensation by selectively adding one of four basic gland seals.
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[0001] This application claims the benefit, under 35 U.S.C. §365 of International Application PCT/EP2011/059728, filed Jun. 10, 2011, which was published in accordance with PCT Article 21(2) on Jan. 5, 2012 under international publication number WO2012000777 in English and which claims the benefit of French patent application No. 1055318, filed Jul. 1, 2010.
FIELD OF THE INVENTION
[0002] The present invention relates to a multimedia mobile terminal capable of transmitting and receiving signals compliant with several standards in the UHF band.
BACKGROUND OF THE INVENTION
[0003] The growing number of multimedia services and standards used for the implementation of these services, such as the standards GSM (Global System for Mobile communications), WiFi (Wireless Fidelity), UMTS (Universal Mobile Telecommunications System), GPS (Global Positioning System), DVB-T (Digital Video Broadcasting—Terrestrial), DVB-H and WiMAX (Worldwide Interoperability for Microwave Access), makes the management of the radio frequency spectrum more and more difficult.
[0004] In this context, it was decided to assign to these services at least part of the resources of frequencies released by the switchover of television broadcasting from analogue mode to digital mode. The sub-band [790 MHz-862 MHz], commonly called digital dividend, has already been assigned for these service types. The programmed switchover to all-digital will also enable the local use, under certain conditions, of channels in the UHF band [470 MHz-790 MHz] for the broadcast of digital television but also for other applications and services. This band of frequencies, commonly called “white space” is the subject of great interest on the part of all actors in the domain of multimedia and telecommunications services. Moreover, this band of frequencies is particularly sought after by telecommunications operators, due to a superior level of efficiency with respect to frequencies higher than 1 GHz, in terms of coverage and penetration of buildings, and in terms of very much lower costs for the creation and operation of networks.
[0005] Access to these new frequencies will generate the development of user terminals, particularly mobile terminals, offering to users in mobile situations or at home a wide range of services (digital television, telephone, Internet, etc.). These multimedia terminals will integrate more and more new functions to respond, on one hand, to the multiplication of access networks, and, on the other hand, to the emergence of new applications and services, such as for example digital television on mobile terminals or home wireless networks.
[0006] In this context, one of the major issues is to enable the mobile terminal to transmit and receive simultaneously signals belonging to the same band of frequencies, particularly in the digital dividend or “white space”, and corresponding to different applications or services, without the reception being too degraded.
[0007] For example, in the case of a mobile terminal capable of receiving a DVB-H signal and accessing a WiMAX type mobile network and a GSM type mobile telecommunications network, said terminal must be capable when it accesses the WiMAX network and/or the GSM network, of receiving DVB-H signals although the frequency of WiMAX signals transmitted by the terminal is very close to the frequency of the DVB-H signal. In fact, in a standard operating mode, the transmission of signals to the WiMAX network can interfere with the DVB-H reception due to the physical proximity of antennas on the terminal and the significant coupling that results.
[0008] One purpose of the present invention is to propose a multi-standard multimedia mobile terminal enabling these problems of reception due to the proximity in frequencies of transmitted and received signals to be resolved.
SUMMARY OF THE INVENTION
[0009] For this purpose, the present invention proposes a multi-standard multimedia mobile terminal comprising:
a receiver receiving a first signal compliant with a first standard in a first frequency band, a first transmitter capable of transmitting a second signal compliant with a second standard in a second frequency band different from the first frequency band and partially intersecting the first frequency band,
wherein
between the receiver and the antenna, a calibrated band-rejection filter comprising at least one variable element enabling the selection of a rejection frequency by the control voltage of said variable element. a filtering control element to store the control voltage values and the associated rejecting frequency values determined during a calibration procedure and to transmit according to the second frequency of the first transmitter the stored control voltage of said variable element of said band-rejection filter.
[0014] Advantageously, the band-rejection filter comprises at least one variable element, for example a capacitor, to be able, despite the dispersions and the tolerances of components of the filter, to precisely adjust the rejection frequency of the filter onto the frequency of the second signal.
[0015] Advantageously, the terminal also comprises a first shunt to short-circuit said band-rejection filter when said first transmitter does not transmit a second signal or when the signal-to-noise ratio at the output of the receiver is greater than a threshold value.
[0016] Advantageously, the second frequency band is comprised between a third frequency and a fourth frequency, said fourth frequency being greater than aid third frequency and interfering with said first frequency band.
[0017] According to a particular embodiment, the terminal also comprises:
a second transmitter capable of transmitting a third signal compliant with a third standard in a third band of frequencies comprised between the frequencies f 5 and f 6 , with f 6 >f 5 and f 5 >f 4 and f 5 >f 2 , and a low-pass filter, upstream of the said receiver, in order to, when said second transmitter transmits a third signal, filter said third signal.
[0020] The function of this low-pass filter is to suppress, upstream of the receiver, the interfering signals for which the frequency is greater than f 4 .
[0021] According to a particular embodiment, a shunt circuit is also provided to short-circuit said low-pass filter when said second transmitter does not transmit a third signal.
[0022] According to a particular embodiment, said first band of frequencies and said second band of frequencies are comprised at least partially in the band [470 MHz-862 MHz] corresponding to the digital dividend and “white space”, or in the band [470 MHz-790 MHz].
[0023] According to a particular embodiment, the first standard is the DVB-H standard, the second standard is the WiMAX standard and/or the third standard is the GSM standard.
[0024] The invention also relates to a method for calibration of the band-rejection filter of the previously defined terminal. Said method comprises the following steps for:
[0000] E 1 ) initializing a frequency fat the frequency f 3 ;
E 2 ) transmitting a second signal at the frequency f via said first transmitter;
E 3 ) adjusting the receiving frequency of the receiver at the frequency f;
E 4 ) varying the control voltage of said at least one variable element of the band-rejection filter so as to determine the control voltage of said at least one variable element enabling the amplitude of the baseband signal at the receiver output to be minimized;
E 5 ) storing in a memory of the terminal the control voltage of said at least one variable element determined in step d);
E 6 ) checking whether the frequency f is equal to the frequency f 2 , and
E 7 ) incrementing the frequency f with a predetermined frequency step and repeating steps E 2 ) to E 6 ) until the frequency f is equal to f 2 .
[0025] Preferably, the power of the second signal transmitted during step b) is low, preferably in the order of −45 dBm in order not to interfere with the reception of other terminals present in the same area.
[0026] According to a particular embodiment, the method for calibration is carried out upon powering up of the mobile terminal and/or periodically.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention will be better understood, and other aims, details, characteristics and advantages will appear more clearly during the following detailed explanatory description by referring above to the annexed drawings, which represent:
[0028] FIG. 1 , a diagram of frequency bands assigned for the standards DVB-H, WiMAX and GSM;
[0029] FIG. 2 , a multi-standard mobile terminal capable of receiving DVB-H signals and of transmitting and receiving WiMAX and GSM signals;
[0030] FIG. 3 , a diagram of said terminal of FIG. 2 ;
[0031] FIG. 4 , a diagram of a band-rejection filter of the terminal of FIG. 3 ;
[0032] FIG. 5 , a flow chart of the method for control of the terminal of the invention, and
[0033] FIG. 6 , a flow chart of a method for calibration of the band-rejection filter of the terminal of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] The invention will be described in the context of a multi-standard mobile terminal capable of receiving DVB-H signals, of transmitting and receiving WiMAX signals, and of transmitting and receiving GSM signals, the DVB-H signals and the WiMAX signals being comprised in the band of frequencies [470 MHz-862 MHz] of the digital dividend and of the “white space”.
[0035] An example of frequency bands assigned to these standards is shown on FIG. 1 . The DVB-H signals are contained in the band of frequencies extending between the frequency f 1 =470 MHz and the frequency f 2 =790 MHz. The WiMAX signals are contained in the band of frequencies extending between the frequency f 3 =698 MHz and the frequency f 4 =862 MHz. Finally, the GSM signals are contained in the band of frequencies extending between the frequency f 5 =890 MHz and the frequency f 6 =915 MHz for the transmission and the band of frequencies extending between the frequency f 7 =890 MHz and the frequency f 8 =915 MHz for the reception. Any transmission via the terminal in the band of frequencies [470 MHz-790 MHz] or in a close band can interfere with the reception of DVB-H signals.
[0036] As illustrated in FIG. 2 , the transmission of WiMAX signals in the frequency band [698 MHz-790 MHz] can interfere with the reception of DVB-H signals just like the transmission of GSM signals in the frequency band [890 MHz-915 MHz] can interfere with the reception of DVB-H signals and WiMAX signals. Therefore, filtering means are provided upstream of the receiver to filter these interfering signals.
[0037] In reference to FIG. 3 , the mobile terminal comprises first means 10 to receive and process the DVB-H signals, second means 20 to transmit, receive and process the WiMAX signals and third means 30 to transmit, receive and process the GSM signals.
[0038] The first means 10 are connected on the one hand to an antenna 11 and on the other hand to a user interface 40 of the terminal. The first means 10 comprise a receiver 102 the input of which is connected, via filtering means 100 and 101 , to the antenna 11 and the output of which is connected to the input of a processing circuit 103 . The output of the processing circuit 103 is connected to the user interface 40 . The receiver 102 extracts from the signal coming from the filtering means 100 and 101 a baseband signal, which baseband signal is then processed by the processing circuit 103 .
[0039] The filtering means 100 and 101 are cascaded upstream of the receiver 102 . The function of the filtering means 100 is to filter, upstream of the receiver 102 , the GSM signals transmitted via the terminal. They comprise a switch 100 a connected in parallel with a low-pass filter 100 b capable of filtering the GSM signals. The cut-off frequency of the low-pass filter 100 b is equal to f 5 =890 MHz. The switch 100 a is used to shunt the low-pass filter 100 b when the terminal does not transmit GSM signals. It is closed when the terminal does not transmit GSM signals and open when the terminal transmits GSM signals.
[0040] The function of the filtering means 101 is to filter upstream of the receiver 102 the WiMAX signals if the reception of the DVB-H signals is poor, i.e. when the signal-to-noise ratio at the output of the receiver 102 is not high enough. The filtering means 101 comprise a switch 101 a connected in parallel with a band-rejection filter 101 b capable of filtering the WiMAX signals. The centre frequency of the band-rejection filter 101 b is adjusted onto the WiMAX transmitting frequency. The switch 101 a is used to shunt the band-rejection filter 101 b when the terminal does not transmit WiMAX signals or when the signal-to-noise ratio at the output of receiver 102 is greater than a threshold value, for example 20 dB. It is closed when the terminal does not transmit WiMAX signals or when the signal-to-noise ratio at the output of the receiver 102 is greater than a threshold value and it is open in the other cases.
[0041] According to a particular embodiment, the filtering means 100 and 101 are integrated together. An example of integrated filter is shown in FIG. 4 . The overall structure of this filter is described in the document called “Exact Synthesis of Microwave Filters with Nonuniform Dissipation”, of C. Guyette et al., IEEE IMS-2007.
[0042] This filter, referenced 7 , comprises, between an input port 71 and an output terminal 72 of the filter, a first transmission channel, called direct channel 73 , to which a second transmission channel, called secondary channel 74 , is coupled. These two channels are materialized by micro-strip transmission lines, also called micro-strip lines.
[0043] The direct channel 73 comprises transmission line portions forming the low-pass filter 100 b and the switch 100 a.
[0044] The secondary channel 74 comprises transmission line portions forming the band-rejection filter 101 a and the switch 101 b . Said secondary channel forms a resonant element the resonant frequency of which corresponds to the frequency to be rejected. The band-rejection filter comprises at least one variable capacitor enabling the rejection frequency (or centre frequency) of the filter to be adjusted. The two switches for example are materialized by diodes.
[0045] The filter topology is defined in order that, at the resonant frequency of the secondary channel, the signal coming from the direct channel 73 and that coming from the secondary channel 74 combine in phase opposition at the filter output to create a theoretically infinite attenuation in a relatively narrow band around the resonant frequency.
[0046] By referring again to FIG. 3 , the second means 20 relating to the WiMAX signals are connected on the one hand to an antenna 21 and on the other hand to the user interface 40 . They comprise a transmitter-receiver 202 comprising more particularly a receiver 202 a and a transmitter 202 b.
[0047] The input of the receiver 202 a is connected, via filtering means 201 , to the antenna 21 and the output of the receiver 202 a is connected to an input of a processing circuit 203 . The receiver 202 a extracts from the signal coming from the filtering means 201 a baseband signal which is then processed by the processing circuit 203 . The processing circuit 203 is moreover connected to the user interface 40 .
[0048] The input of the transmitter 202 b is connected to an output of the processing circuit 203 and the output of the transmitter 202 b is connected to the antenna 21 . A switch 200 is provided to selectively connect the antenna 21 to the input of the filtering means 201 or to the output of the transmitter 202 b.
[0049] The function of the filtering means 201 is to filter upstream of the receiver 202 a the GSM signals when the terminal transmits such signals. They comprise a switch 201 a connected in parallel with a low-pass filter 201 b capable of filtering the GSM signals. The cut-off frequency of the low-pass filter 201 b is equal to f 5 =890 MHz. The switch 201 a is used to shunt the low-pass filter 201 b when the terminal does not transmit GSM signals. It is closed when the terminal does not transmit GSM signals and open when the terminal transmits GSM signals.
[0050] Finally, the third means 30 relating to the GSM signals are connected on the one hand to an antenna 31 and on the other hand to the user interface 40 . They comprise a transmitter-receiver 302 comprising more particularly a receiver 302 a and a transmitter 302 b.
[0051] The input of the receiver 302 a is connected to the antenna 31 and the output of the receiver 302 a is connected to an input of a processing circuit 303 . The receiver 302 a extracts from the signal coming from the antenna 31 a baseband signal which is then processed by the processing circuit 303 . The processing circuit 303 is moreover connected to the user interface 40 .
[0052] The input of the transmitter 302 b is connected to an output of the processing circuit 303 and the output of the transmitter 302 b is connected to the antenna 31 . A switch 300 is provided to selectively connect the antenna 31 to the input of the receiver 302 a or to the output of the transmitter 302 b.
[0053] The terminal also comprises a control circuit 50 intended to control the filtering means 100 , 101 and 201 . The control circuit 50 receives signals coming from the processing circuits 103 , 203 and 303 as well as the baseband signal coming from the receiver 102 . It determines the signal-to-noise ratio of the baseband signal coming from the receiver 102 and determines the command to be applied to the filtering means 101 according to this ratio.
[0054] The operating mode of the terminal is described in more detail in reference to FIG. 5 .
[0055] When the receiver 102 (DVB-H) operates, the control circuit of the filters 50 checks whether the terminal transmits a GSM signal. If it transmits a GSM signal, it is filtered, upstream of the receivers 102 and 202 , using the filters 100 b and 201 b . In the absence of GSM signal, the filters 100 b and 201 b are shunted by means of the switches 100 a and 201 a.
[0056] The control circuit of the filters 50 then checks on the one hand whether the terminal transmits a WiMAX signal and, on the other hand, whether the signal-to-noise ratio of the baseband signal at the output of the receiver 102 is sufficient (greater than the threshold value). If the terminal transmits a WiMAX signal, and if the signal-to-noise ratio is sufficient, upstream of the receiver 102 , the WiMAX signal is filtered using the filter 101 b . In the absence of WiMAX signal, the filter 101 b is shunted by means of the switch 101 a.
[0057] This operating phase is preferably preceded by a calibration phase of the band-rejection filter 101 b . This calibration phase is intended to determine and store, for each frequency of the WiMAX signal comprised in the DVB-H frequency band, the control voltage of the variable element or variable elements of the filter enabling this frequency to be filtered. In the case of a band-rejection filter comprising a variable capacitor, this involves determining and storing the control voltage of this capacitor for each of the WiMAX signal frequencies comprised in the DVB-H frequency band.
[0058] The WiMAX signal frequencies comprised in the DVB-H frequency band are comprised in the frequency band [698 MHz-790 MHz], i.e. [f 2 , f 3 ].
[0059] In reference to FIG. 6 , this calibration phase comprises the following steps for:
step E 1 : initializing a frequency fat the frequency f 3 , step E 2 : transmitting a WiMAX signal at the frequency f, step E 3 : adjusting the receiving frequency of the receiver 102 at the frequency f and, possibly, adjusting the control voltage of the variable element or elements of the filter at a predefined value enabling the centre frequency of the band-rejection filter to be roughly adjusted at the frequency f, step E 4 : varying the control voltage of the variable element or elements of the band-rejection filter, preferably around the predefined value, so as to determine the precise control voltage or voltages enabling the baseband signal amplitude at the output of the receiver 102 to be minimized; the measurement of the baseband signal amplitude at the output (I/Q output) of the receiver 102 is performed by a circuit internal or external to the control circuit 50 , step E 5 : storing the control voltage of the variable element or elements determined in step E 5 in a memory of the control circuit 50 , step E 6 : checking whether the frequency f is equal to f 2 , and step E 7 : incrementing the frequency f with a predetermined frequency step and recommencing steps E 2 to E 6 until the frequency f is equal to f 2 .
[0067] Owing to the significant coupling between the antennas of the terminal, particularly between the antennas 11 and 21 , the transmission of the WiMAX signal during step E 2 can be performed with a low transmitting level, this transmitting level being defined to be detectable by the receiver 102 while impeding as little as possible the reception of multimedia terminals placed in the vicinity of the present terminal.
[0068] For a receiver 102 (DVB-H) of sensitivity equal to −95 dBm with a signal-to-noise ratio of 10 dB, an average receiving level of 40 dB above the sensitivity threshold and an isolation between the antennas of 10 dB, the required power level is equal to −95+40+10=−45 dBm.
[0069] According to the invention and following this calibration phase, for each WiMAX signal transmitting frequency, the control circuit of the filters 50 emits a control voltage determined during this calibration phase which enables the variable elements of the filter to be dynamically selected to obtain the rejection frequency corresponding to the transmitting frequency of the WiMAX signal.
[0070] According to the invention, the control voltages determined during this calibration phase are all the more precise that all the local oscillators of the terminal transmitters and receivers depend on the same reference signal. So, during this calibration phase, the frequency of the local oscillator of the receiver 102 (DVB-H) is a multiple of or is equal to the frequency of the local oscillator of the transmitter 202 b (WiMAX).
[0071] The calibration phase is performed upon the powering up of the terminal and/or periodically. Such a structure and such an operation of the terminal according to the invention enable the DVB-H reception to be dynamically optimized on the terminal according to the services requested by the user.
[0072] Naturally, the invention is not limited to DVB-H/WiMAX/GSM terminals. It applies to all types of terminals receiving and transmitting in the same frequency band signals of different standards. Although the invention has been described in relation to a specific embodiment, it is evident that this is in no way restricted and that it comprises all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.
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The present invention relates to a multimedia mobile terminal capable of transmitting and receiving signals compliant with several standards in the UHF band. It comprises:
a receiver receiving a first signal compliant with a first standard in a first frequency band,
a first transmitter capable of transmitting a second signal compliant with a second standard in a second frequency band different from the first frequency band and partially intersecting the first frequency band,
wherein, between the receiver and the antenna, a calibrated band-rejection filter comprising at least one variable element enabling the selection of a rejection frequency by the control voltage of said variable element. a filtering control element to store the control voltage values and the associated rejecting frequency values determined during a calibration procedure and to transmit according to the second frequency of the first transmitter the stored control voltage of said variable element of said band-rejection filter.
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RELATED APPLICATION DATA
[0001] This application claims priority of U.S. Provisional Application No. 60/882,772 filed on Dec. 29, 2006, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical navigation and, more particularly, to a marker system for determining a diameter and axial location of a bore or hole in an object.
BACKGROUND OF THE INVENTION
[0003] Marker means are currently detected by means of a detection means (e.g., a camera or ultrasound detector). The marker means typically comprise three markers arranged in a fixed and predetermined location relative to each other and can be mechanically connected. The markers can be passive or active markers, wherein passive markers reflect signals (e.g., waves and/or radiation) emitted in their direction, and active markers are themselves the source of the signals (e.g., waves and/or radiation). The signals emitted from the (active or passive) markers, which can be wave signals or radiation signals, are detected by the detection means. In order to establish a position of the marker means relative to the detection means, the marker means is preferably moved to provide the detection means with different views of the marker means. On the basis of this, the location of the marker means relative to the detection means then can be determined in a known way, in particular in a spatial reference system. Reference is made in this respect to DE 196 39 615 A1 and the corresponding U.S. Pat. No. 6,351,659, each of which are hereby incorporated by reference in their entirety.
SUMMARY OF THE INVENTION
[0004] A marker system is provided that enables a diameter and axial location of a rotationally symmetrical hole or bore in an object (referred to hereinafter as an instrument) to be determined. The term “rotationally symmetrical” as used herein relates to the axis of the hole or bore, i.e., the surface area which surrounds and delineates the hole has a shape which is rotationally symmetrical with respect to the axis in the longitudinal direction (insertion direction into the hole). Examples of rotationally symmetrical holes include cylindrical holes (bores or transit bores), but also can include, for example, conical holes or holes that are configured to be partially spherical (e.g., hemispheres). The term “hole” here includes both transit holes, which penetrate through the instrument, and a recess in the instrument. The marker system can include a body to which markers are attached (referred to as “body markers” below). The body markers can be situated in a predetermined arrangement relative to each other and can exhibit a prior-known size and shape (e.g., a spherical shape). The body thus can comprise a marker means. Preferably, the instrument also comprises a marker means, as will be discussed in more detail below. In general, the following applies to marker means.
[0005] The location of the marker means is preferably determined by the position of the marker means in a predetermined reference system. The reference system can be a reference system in which the detection means lies. The location of the marker means can be determined by the positions of the markers, in particular center points of the markers, in the reference system. The positions, for example, can be described using Cartesian coordinates or spherical coordinates. The location of one part (e.g., the detection means or marker means) relative to another part (e.g., the marker means) can be described by spatial angles and/or distances and/or coordinates (in a reference system) and/or vectors and is preferably calculated from the positions describing the location, for example by means of a program running on a computer.
[0006] The term “relative location” used here or the expression “location of a part A relative to a part B” thus comprises the concept of the relative positions between the two parts, in particular between the marker means and/or their markers or between a marker means (or its markers) and the detection means. In particular, centers of gravity or center points of the parts can be selected as a punctiform reference point for establishing a position. If the position of one part is known in a reference system, then it is possible, based on the relative location of two parts, to calculate the position of one of the two parts from the position of the other of the two parts.
[0007] If the marker means comprises only two markers, a start position is preferably known, and the marker system then allows the location of the marker means to be tracked when the marker means is spatially moved.
[0008] The marker means in accordance with the present invention preferably comprises at least two markers, and more preferably three markers. The dimensions of the markers and the location of the markers relative to each other are known and may be available as prior-known data of a data processing means. The shape of the markers is preferably also known.
[0009] The marker system preferably also comprises a detection means that detects signals from the at least two markers. As stated above, these signals may be emitted from the markers (either actively emitted by the markers or reflected by the markers). In the latter case, a signal transmitting source, for example an infrared light source, is preferably provided that emits signals (e.g., ultrasound pulses or infrared light) toward the passive markers, wherein the passive markers reflect the signals. A data processing means, such as a computer, allows the location of the marker means relative to the detection means to be calculated, in particular the location of the marker means in a reference system in which the detection means lies, e.g., in a reference system which lies in an operating theater.
[0010] If the body has then been provided with a marker means and the instrument to be examined has also been provided with a marker means, then it is possible to determine the relative location of the body relative to the instrument. The location of the axis of the hole relative to the marker means attached to the instrument, and the shape of the hole, are however still unknown.
[0011] In order to determine the location of the axis, body markers can be provided on the body as well as rotationally symmetrical extensions. These extensions, for example, can have a cylindrical configuration or a conical configuration (including a truncated cone).
[0012] An operator who wishes to measure a characteristic (e.g., a diameter) of a hole in an (arbitrary) instrument uses an instrument that is provided with a marker means. The markers of the marker means are referred to here as “instrument markers”, in order to distinguish them from the body markers. The operator searches out the extension that has a diameter that is substantially the same as the diameter of the hole and rotates the instrument around this hole while the signals emitted by the instrument markers are detected by the detection means. As used herein, substantially the same diameter refers to diameters that are nearly identical (e.g., an exact fit that permits movement of the hole relative to the extension, with little to no interference). Due to the embodiment of the marker system in accordance with the invention, this approach allows both the shape of the hole (e.g., the diameter of a cylindrical hole) and the location of the axis of the hole to be determined.
[0013] The detection means in accordance with the invention is embodied to detect signals emitted both by the body markers and by the instrument markers. This allows the data processing means to determine the location of the body markers relative to the instrument markers. In order to make this and/or other determinations, the detection means preferably converts the detected signals into data signals and outputs them to the data processing means.
[0014] The data processing means is preferably designed to perform the functions (described in more detail below) of receiving, storing, calculating and determining. The data processing means receives the data signals output by the detection means. In other words, the data processing means receives data signals that represent the location of the body markers relative to the detection means, and data signals that represent the location of the instrument markers relative to the detection means. As already stated above, the instrument is preferably rotated by an operator around an extension that has been fit into the hole in the instrument. A number of locations of the instrument markers relative to the detection means thus arise during this rotational movement. Preferably, at least three locations of the instrument markers relative to the detection means are provided in accordance with the invention. The data processing means can be designed to receive and further process at least three different locations of the instrument markers relative to the detection means. When further processing the different relative locations of the instrument markers (relative to the detection means), it is then preferably assumed that these relative locations lie on a circular trajectory.
[0015] An approximating method (fitting method such as for example a least-square fit) is preferably performed to calculate a circular trajectory from the three relative locations, on which the three relative locations at least approximately lie. The data processing means thus has the function of calculating a circular trajectory and the assumption that the at least three different relative locations lie on a circular trajectory. In order to mathematically describe a circular trajectory, the location of the center point and the radius of the circular trajectory, and in particular trigonometric functions (e.g., sine, cosine), are preferably used. Calculating the circular trajectory thus also calculates the location of the center point of the circular trajectory and determines the center point relative to the detection means. Since the location of the center point of the circular trajectory matches the location of the axis of the hole in the instrument, the location of the axis of the hole relative to the detection means is thus also determined.
[0016] However, the aforementioned method step of fitting an extension into an instrument hole and then rotating the instrument around said extension not only allows the relative location of the axis of the hole to be determined, but also allows the shape of the hole to be determined. The shape of the hole is preferably described by one or more characteristics. In the case of a cylindrical hole and thus a cylindrical extension, this at least one characteristic, for example, can be the diameter or radius of the hole, and additionally the height of the cylindrical extension. It is, however, also possible to provide rotationally symmetrical extensions of different shapes on the body, e.g., cylindrically shaped, conically shaped or spherically shaped extensions. In this case, the at least one characteristic preferably also includes a characteristic that indicates the configuration, e.g., cylindrical, conical or spherical. If, for example, there are only conically configured extensions comprising a conical tip (i.e., not truncated cones), then the at least one characteristic preferably includes the aperture angle of the cone. In the case of a truncated cone, the height of the truncated cone and/or the radii or diameters of the faces enclosing the truncated cone, for example, may be other characteristics.
[0017] In accordance with the invention, the data processing means is designed to determine the at least one characteristic. To this end, the relative locations between the body markers and the axes of the rotationally symmetrical extensions are preferably known and stored in the data processing means. The aforesaid characteristics also can be stored in association with the aforesaid relative locations of the axes relative to the body markers. In particular, at least one characteristic is stored in association with each individual axis.
[0018] It is thus possible to calculate, from the data signals, which of the axes match the calculated center point. It is in particular possible to calculate the relative location of the center point and, therefore, of the axis relative to the detection means. From the detected location of the body markers and the stored data concerning the location of the body markers relative to the axes, it is then possible to determine which of the axes matches the center point.
[0019] Detecting the instrument markers thus allows the location of the center point of the circular trajectory relative to the detection means to be determined. Detecting the body markers allows the location of the axes relative to the detection means to be determined. Thus, it is possible to determine which of the respective determined locations of the axes relative to the detection means matches the determined location of the center point relative to the detection means. Further, it is possible to determine which axis matches the center point, so as to identify the axis.
[0020] If the axis has then been identified, it is then possible to determine, from the stored association between the axis and the characteristics, the characteristic that is associated with the identified axis. The aforesaid method step thus enables both the location of the axis relative to the detection means and therefore also relative to the instrument markers to be determined. In addition, it is simultaneously possible to determine the characteristic of the hole in the instrument. The instrument is thus registered and can be used in any way. The determined location of the axis of the hole relative to the instrument markers, and the at least one characteristic which characterizes the shape of the hole can be stored for a later application of the instrument.
[0021] As already stated above, the arrangement of the body markers relative to each other may be known and preferably stored. This arrangement differs from the arrangement (and as applicable the shape) of the instrument markers, which also may be stored. The markers are preferably all spherical. Due to the characteristic arrangement of the body markers and the characteristic arrangement of the instrument markers, it is possible to distinguish the body markers from the instrument markers. When processing the data signals, the data processing means can thus recognize which data signals are to be associated with the body markers and which are to be associated with the instrument markers.
[0022] The distance between two extensions is preferably larger than the diameter of one of the extensions, in particular larger than the maximum diameter of the extensions. A preferred range is around 100 to 300% of the diameter of the extension.
[0023] The surface from which the extensions protrude is preferably convexly curved or planar. This enables the instrument to be placed directly onto the surface and simultaneously to not obstruct the instrument from being rotated around the extension when the extension has been inserted into the hole in the instrument. A planar embodiment of the surface is preferred, since it is possible to laterally guide the instrument during the rotational movement around the axis of the extension. The intersection points between the axis of the extensions and the aforesaid surface preferably represent points that lie on a trajectory. The trajectory, for example, can be a straight line or a curved line, in particular a closed line (for example a circle or ellipse). This arrangement means that rotating the instrument around one of the axes of the extensions is not obstructed by other extensions.
[0024] Alternatively or additionally, the extensions also can be arranged one above the other, such that the axes of the extensions transition into each other, wherein the diameter of the extensions decreases as the distance from the aforesaid surface increases. The diameter preferably decreases in steps (see FIG. 4 ).
[0025] The body on which the extensions are provided also can be designed in a number of parts. One part of the body, which is referred to here as the “extension body” and on which the extensions are provided, can in particular be separate from another part of the body which is referred to here as the “marker unit”. A marker means can be provided on the marker unit. In this way, differently configured marker means can be connected to the extension body, so as to be able to use a marker means, which is suitable for the respective application purpose, as the body marker. On the other hand, a number of different extension bodies can of course be connected to a particular marker means. It is then for example possible to select, depending on the shaping of the hole, an extension body comprising cylindrical extensions or one comprising conical extensions, or to select extension bodies having different diameters or characteristics. The connection between the two parts is preferably releasable and, when the parts are connected, spatially fixed, i.e., a relative movement between the marker unit and the extension body is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The forgoing and other features of the invention are hereinafter discussed with reference to the drawings.
[0027] FIG. 1 illustrates an exemplary extension body with markers coupled thereto.
[0028] FIG. 2 a is a front view of the extension body of FIG. 1 .
[0029] FIG. 2 b is a lateral view of the extension body of FIG. 1 .
[0030] FIG. 2 c is a rear view of the extension body of FIG. 1 .
[0031] FIG. 3 illustrates an exemplary marker system in accordance with the invention.
[0032] FIG. 4 illustrates an alternative arrangement of the extensions on an extension body.
DETAILED DESCRIPTION
[0033] The exemplary extension body 1 shown in FIG. 1 comprises a number of extensions 8 , 9 , 10 and 11 . The extension 8 has an axis A 8 , the extension 9 has an axis A 9 , the extension 10 has an axis A 10 and the extension 11 has an axis A 11 . As shown in FIG. 1 , the extensions preferably protrude from a level plane 30 of the extension body 1 . In the exemplary extension body of FIG. 1 , the extensions are designed cylindrically, i.e., they have a constant diameter along their axes. The diameters of the respective extensions preferably differ, and the extensions are preferably arranged in a row. Further, the distance between each extension is preferably at least as large as the diameter of the adjacent extension, and more preferably larger than the diameter of the extension with the largest diameter. The extensions preferably protrude from the plane 30 by the same distance.
[0034] The marker unit 2 comprises three markers 3 , 4 , and 5 having a preferably spherical configuration, wherein a diameter of each marker is the same. The location of the markers 3 , 4 and 5 relative to each other is preferably known and in particular characteristic of the marker unit 2 . It is thus possible to recognize, from the characteristic arrangement of the markers 3 , 4 and 5 , the marker unit 2 .
[0035] In the embodiment shown in FIG. 1 , the marker unit 2 is designed as a calibrating device, wherein for calibrating purposes, instruments can be placed on planes of the marker unit 2 or inserted into openings to perform a calibration. This secondary function of the marker unit 2 , however, is not further discussed herein.
[0036] FIG. 2 a shows a front view of the extension body 1 , wherein the extensions 8 , 9 , 10 and 11 are shown in a top view as circles of different diameters. FIG. 2 b shows a lateral view of the extension body 1 , wherein to the right of the plate 32 that includes the front plane 30 , the extensions 8 , 9 , 10 and 11 are arranged in a row from top to bottom. A coupling member 12 is situated on the rear side 34 of the plate 32 and protrudes from the planar rear side 34 . The coupling member 12 is shown in more detail in FIG. 2 c . FIG. 2 c is a rear view of the extension body 1 , in which the coupling member 12 is shown in a top view. It consists of a circular portion 12 b and an extension 12 a which protrudes from the circular member 12 b and blocks rotation.
[0037] As shown in FIG. 1 , the circular portion 12 b is inserted into the circular opening 6 of the marker unit 2 , as indicated by the arrow B. In addition, the extension 12 a is inserted into the complementarily designed recess 7 of the marker unit 2 . The extension 12 a , in cooperation with the recess 7 , thus prevents the extension body 1 from rotating relative to the marker unit 2 . The coupling member 12 is preferably configured in an exact fit to ensure a stable relative location between the extension body 1 and the marker unit 2 . Additionally or alternatively, a catch-like coupling can also be provided.
[0038] FIG. 3 shows the assembly of a marker system in accordance with the invention. Identical reference signs duly designate identical parts, as in the preceding figures. In FIG. 3 , the extension body 1 is coupled and positionally fixed to the marker unit 2 such that the extension body 1 cannot be moved relative to the marker unit 2 . An exemplary instrument 14 is also shown, which can be measured in conjunction with the marker system. The rod-shaped configuration of the instrument 14 is merely by way of example. Other embodiments of the instrument, such as for example a triangular configuration, are of course possible. The extension 11 penetrates through a cylindrical opening (transit bore) in the instrument 14 in an exact fit, such that the axis of the extension 11 matches the axis of the cylindrical opening in the instrument 14 . A marker means 13 is provided at an end of the instrument 14 opposite the end near which the cylindrical opening is situated. The instruments are preferably configured such that the marker means 13 is situated as far away as possible from the cylindrical opening to be measured to more exactly determine the center point of the circular trajectory 20 on which the marker means 13 is moved. The distance between the marker means 13 and the center point of the rotational movement is preferably a multiple of the diameter of the cylindrical opening, and more preferably more than five times or ten times the diameter. The present invention is applicable to instruments comprising a marker means that are suitably configured in this way.
[0039] The markers 13 a , 13 b and 13 c can be active markers that emit signals (e.g., light or ultrasound). Preferably, however, the markers are passive markers that reflect signals emitted in their direction. An infrared light source, for example, can be provided that continuously or intermittently emits infrared light, which is reflected by the marker spheres 13 a , 13 b , 13 c , 3 , 4 and 5 . The camera 100 , which is preferably designed as a camera comprising two spatially separate detection elements, receives the signal (e.g., infrared light) emitted by the marker spheres 3 , 4 , 5 , 13 a , 13 b and 13 c . The marker spheres 3 , 4 and 5 and the marker spheres 13 a , 13 b and 13 c , respectively, are in a characteristic positional relationship with respect to each other. This characteristic positional relationship is preferably known. For example, the center points of the marker spheres 3 , 4 and 5 enclose a triangle, the side lengths and angles of which are preferably known. The center points of the marker spheres 13 a , 13 b and 13 c correspondingly enclose a triangle, the side lengths and angles of which are known. If both the marker array comprising the spheres 3 , 4 and 5 and the marker array comprising the spheres 13 a , 13 b and 13 c have thus been characterized by the side lengths and angles of the respective triangle, then the data processing means 200 can ascertain, from the data signals transmitted from the camera 100 , which marker array the signals originated from.
[0040] In order to determine the position of the axis of the cylindrical opening and the diameter of the cylindrical opening in the instrument 14 , the following procedure can be performed. The instrument 14 can be rotated around the axis of the extension 11 along the circular trajectory 20 , such that at least three positions are detected by the camera 100 and thus also by the data processing means 200 .
[0041] From the data signals emitted from the marker means 13 , the data processing means 200 then calculates the center point of the circular trajectory along which the marker means 13 has moved. The center point of this circular trajectory matches the axis of the extension 11 . The relative location between the marker array comprising the spheres 3 , 4 and 5 and the individual extensions, in particular the extension 11 , is also known. The location of the extension 11 is thus also known from the detected signals from the marker array comprising the spheres 3 , 4 and 5 and from the stored relative location between the spheres 3 , 4 and 5 and the respective extensions, in particular the extension 11 . The data processing means can thus verify whether the center point of the circular trajectory 20 matches the location of the axis of the extension 11 . If this is the case, then the location of the axis of the cylindrical opening is thus determined, since it matches the center point of the circular trajectory.
[0042] The location, for example, can be described in a reference system in which the detection means lies. Due to the known location of the center point of the circular trajectory 20 and the known location of the extension 11 , it is also known that the instrument has rotated around the extension 11 . Since the particular geometric properties of the extension 11 , in particular the diameter of the extension 11 , are stored in the data processing means, the diameter of the cylindrical opening in the instrument 14 is thus also known. Thus, both the location of the cylindrical opening and its diameter can be determined by means of the method in accordance with the invention and the marker system in accordance with the invention.
[0043] FIG. 4 shows another alternative embodiment for an extension body 1 ′. The extension body 1 ′ is preferably also connected to a marker means (not shown) which can for example be designed like the array 13 (reference star).
[0044] In the embodiment shown in FIG. 4 , a cylindrical extension protrudes from the front face 30 ′ of the extension body 1 ′, wherein the diameter of said extension decreases in steps as the distance from the surface 30 ′ increases. The height of the steps is preferably larger than the diameter of the largest extension 8 ′. A cylindrical opening in an instrument can also be placed onto the extension body 1 ′ shown in FIG. 4 , wherein the instrument can be moved up against one of the steps or against the front plane 30 ′, depending on the size of the diameter of the opening. Here, too, the instrument is then preferably rotated around the respectively fitting extension 8 ′, 9 ′ or 10 ′. By detecting the signals of the marker array attached to the instrument, it is in turn possible to determine the center point of the rotational movement. It is then possible to determine from the determined location of the center point of the rotational movement which of the extensions 8 ′, 9 ′ or 10 ′ the instrument has been rotated around.
[0045] Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
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A marker system and method are provided that can determine a shape and an axial location of a rotationally symmetrical hole in an instrument having a plurality of instrument markers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a combination of cellulolytic enzymes with cationic and anionic polymers for use in enhancing the freeness of paper pulp.
2. Description of the Prior Art
More and more the papermaking industry uses recycled papers. For example, for the manufacture of corrugated cardboard, raw materials which are based on recycled fibers are being used more frequently and, at the same time, the number of recyclings is increased. With each recycling, the quality of the raw materials is lessened. To obtain a satisfactory level of raw material quality, refining of the pulps in aqueous suspension is generally carried out. This refining leads to difficulties in runnability of the paper sheet because of high concentrations of fines and other contaminants which may be found in the refined pulp.
The pulps in aqueous suspension which are ready to be used on a paper machine can be characterized by various parameters, one of which is particularly significant for predicting the draining capability of the pulp. A measure of the drainability of the pulp is frequently expressed in the term "freeness". Specifically, freeness is measured according to Canadian Standard Freeness, or CSF measurement. CSF measures the drainage of 3 grams (oven dried weight) of pulp suspended in one liter of water.
Use of cellulolytic enzymes, e.g. the cellulases and/or the hemicellulases for treating recycled paper pulps to improve freeness is the subject of U.S. Pat. No. 4,923,565 the disclosure of which is incorporated herein by reference. The cellulase enzyme described in the '565 patent may be used in the practice of the present invention.
U.S. Pat. No. 5,169,497, issued to Sarkar and Cosper discussed the effects of cellulases in combination with cationic flocculants of varying composition on the freeness of old corrugated containers (OCC) pulp. The '497 patent covers the use of a combination of enzyme and cationic polymers for enhancing the freeness of recycled fiber. In practice, dual polymer treatment programs are also used for retention.
In a dual polymer retention system, two synthetic polymers are mixed with the pulp sequentially to achieve better results than obtained with either polymer by itself. Usually, a low molecular weight, highly charged cationic polymer is added to the papermaking furnish first, and then at a later stage, a high molecular weight, anionic polymer is added. Dual polymers have found a place in paper and board manufacturing. Good retention has numerous economic benefits. As the use of recycled fiber increases in container board, fine paper, and newsprint grades, the opportunity to provide benefits through retention aids has also increased. If fines are not retained by a good retention aid or hydrolyzed by an enzyme, they will impede drainage, fill felts, and cause deposition problems. The key benefit of retention aids with enzyme is to prevent drainage reduction and subsequent loss of machine speed. Drainage can be maintained by preventing the build-up of fines in the white water loop.
While the present invention produces particularly good results when used to treat pulps which contain substantial quantities of recycled fibers, it also has applicability in treating pulps which contain little or no recycled fibers.
SUMMARY OF THE INVENTION
A process for improving the freeness of paper pulp, which comprises the steps of adding to the pulp at least 0.05%, based on the dry weight of the pulp, of a cellulolytic enzyme, allowing the pulp to contact the cellulolytic enzyme for from about 40 minutes to about 60 minutes at a temperature of at least 40° C., adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic polymer and forming the thus treated pulp into paper.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is a statistical analysis of the freeness changes of anionic polymer A.
FIG. 2, is a statistical analysis of the freeness changes of anionic polymer B.
FIG. 3, is a contour plot showing the increase in freeness that you use to buy an enzyme dosage of 0.1 percent.
FIG. 4, is a contour plot showing the increase in freeness that you use to buy enzyme of 0.25 percent.
FIG. 5, is a contour plot showing the increase in freeness that you use to buy enzyme of 0.4 percent.
FIG. 6, is a contour plot showing the increase in freeness achieved by a combination of Cationic A, Anionic B and liftase A40.
FIG. 7, is a contour plot showing freeness levels or combinations of Cationic B, Anionic B and Liftase A40.
FIG. 8, is a contour plot showing freeness levels or combination of Cationic C, Anionic B and Liftase A40.
FIG. 9, is a contour plot showing the freeness level achieved by a combination of Cationic A, Anionic B and Lifiase A40.
FIG. 10, is a contour plot showing the effect on the levels of freeness achieved by a combination of Cationic B, Anionic B and Liftase A40.
FIG. 11, is a contour plot showing the freeness achieved by a combination of Cationic C, Anionic B and Liftase A40.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A variety of water soluble cationic coagulants may be used in the practice of the invention. Both condensation and vinyl addition polymers may be employed. For a list of water soluble cationic polymers, reference may be had to Canadian patent 731,212, the disclosure of which is incorporated herein by reference.
A preferred group of cationic polymers are the cationic polymers of acrylamide which in a more preferred embodiment of the invention, contain form 40-60% by weight of acrylamide. Larger or smaller amounts of acrylamide in the polymers may be used, e.g., between 30-80%. Typical of the cationic monomers, polymerized with acrylamide are the monomers diallyldimethyl ammonium chloride, (DADMAC), dimethylaminoethyl/acrylate methyl chloride quaternary ammonium salt, (DMAEA.MCQ). When these cationic acrylamide polymers are used they should have a RSV (reduced specific viscosity) of at least 3 and preferably the RSV should be within the range of 5-20 or more. RSV was determined using a one molar sodium nitrate solution at 30° C. The concentration of the acrylamide polymer in this solution is 0.045%.
A preferred group of anionic polymers are polymers of acrylamide containing 20-95% acrylamide and 5 to 80% anionic monomer by weight of the polymer such as acrylic acid or methacrylic acid.
As indicated, the invention has utility in improving the drainage or the freeness of a wide variety of paper pulps, including Kraft and other types of pulp. The invention is particularly useful in treating pulps that contain recycled fibers. The effectiveness of the invention in improving drainage is most notable when the pulps contain at least 10 percent by weight of recycled fiber, with great improvements being evidenced when the recycled fiber content or the pulp being treated is at least 50% or more.
As indicated, the invention requires that the pulp first be treated with an enzyme, then with a cationic polymer and, finally, with an anionic polymer. It is also important to the successful practice of the invention, that the conditions under which the treatment with the enzyme occurs is such to provide optimum reaction time of the enzyme of the pulp.
The treatment of the pulp with the enzyme is preferably conducted for a period of time not greater than 60 minutes. The minimum treating time is about 30 minutes. A typical treating time would be about 40 minutes. The pH of the pulp to achieve optimum results should be between the ranges of 5 to 7.5. The temperature of the treatment should not be below 20° C., and usually should not exceed 60° C. A typical average reaction temperature is favorably conducted is 40° C.
The preferred dosage of the cationic polymer, as actives, is from 0.025% to 0.02% polymer based on the dry weight of the pulp. A general dosage which may be used to treat the pulp with the polymer is from 0.01% to 0.08% by weight of the polymer. The preferred dosage of anionic polymer, as actives, is 0.025%-0.075% polymer based on the dry weight of the pulp.
The enzyme dosage based on the dry weight of the pulp in a preferred embodiment ranges from about 0.05 to about 0.4 percent by weight. A general treatment range of the enzyme that may be used is from 0.01 to 0.5 percent by weight.
In order for the enzyme to have sufficient reaction time and mixing described above, it is necessary that they be added to the pulp at the point in the paper making system to allow sufficient time for the above conditions to occur. Thus, a typical addition point in paper making system would be the machine chest. Other places where suitable contact time would occur may also be used as additional points.
Since pulp slurry is not homogeneous, it is difficult to take an exact required weight of pulp equivalent to 3 grams. Therefore, at the time of freeness testing, with respect to the data hereafter presented, the consistency of pulp stock was determined by stirring well and then drained in a Buchner funnel. The pulp pad was dried at 105° C. to determine the exact weight of the pad. The CSF data hereafter, reported was corrected to a 0.3% consistency using the table of freeness corrections prepared by the pulp and paper Research Institute of Canada and has been described in TAPPI manual (T227). The CSF values were measured at 20° C.
The following examples are presented to describe preferred embodiments and utilities of the invention and are not meant to limit the invention unless otherwise stated in the claims appended hereto.
EXAMPLE 1
An 18 run response surface design (Table I), in which the effects of enzyme dose, polymer dose and polymer type (Artionic A and Anionic B) on the freeness of pulp were investigated. The pulp slurry consistency of 2.3% (3 g dry wt.), which had a pH 5.6, was first treated for 60 minutes at 40° C. under continuous agitation (250 rpm) with an enzyme solution containing Liftase-A40 (0 to 0.4% based on dry wt. of pulp), and then treated separately for 1 minute with different polymers. The freeness values using only Liftase A40 (0.2 and 0.4% wt./wt basis) were increased from 220 mL (untreated) to 320 and 376 mL, respectively. When Liftase A40 pretreated pulp was further treated with anionic polymers, the freeness of pulp decreased (Table I). Statistical analysis of the data revealed (FIGS. 1 and 2) that in the case of anionic flocculants (Anionic A and Anionic B), the decrease in freeness was almost linear with the increase in flocculant concentration. The freeness of pulp untreated with enzyme was decreased by anionic flocculants (Table I).
TABLE I__________________________________________________________________________EXPERIMENTAL DESIGN LIFTASE-ANIONIC POLYMERS FREENESSRUNS POLYMERS TESTED POLYMER DOSE* ENZYME DOSE** RUN ORDER ML (CSF)__________________________________________________________________________1 Anionic A Acrylamide/Acrylic Acid 1 0 23 190 Copolymers2 Anionic A Acrylamide/Acrylic Acid 3 0 25 150 Copolymers3 Anionic A Acrylamide/Acrylic Acid 2 .2 14 200 Copolymers4 Anionic A Acrylamide/Acrylic Acid 2 .2 18 205 Copolymers5 Anionic A Acrylamide/Acrylic Acid 2 .2 13 207 Copolymers6 Anionic A Acrylamide/Acrylic Acid 1 .4 6 271 Copolymers7 Anionic A Acrylamide/Acrylic Acid 3 .4 21 255 Copolymers8 Anionic B Acrylamide/Acrylic Acid 1 0 4 210 Copolymers9 Anionic B Acrylamide/Acrylic Acid 3 0 22 195 Copolymers10 Anionic B Acrylamide/Acrylic Acid 2 .2 12 242 Copolymers11 Anionic B Acrylamide/Acrylic Acid 2 .2 16 240 Copolymers12 Anionic B Acrylamide/Acrylic Acid 2 .2 19 240 Copolymers13 Anionic B Acrylamide/Acrylic Acid 1 .4 2 308 Copolymers14 Anionic B Acrylamide/Acrylic Acid 3 .4 2 249 Copolymers15 -- 0 0 7 22016 -- 0 .2 3 32017 -- 0 .2 11 32318 -- 0 .4 24 376__________________________________________________________________________ DOSE* = POUNDS PRODUCT/TON DRY PULP DOSE** = LIQUID PREPARATION ON DRY WEIGHT BASIS OF PULP
Results obtained using anionic flocculants are in contrast with previous results obtained using cationic flocculants. These results suggest that the anionic flocculants tested were not adsorbed on the fiber and they might have simply remained in the solution. Lack of adsorption of these flocculants on the fiber and consequent high viscosity of the pulp slurry, due to the presence of polymer, might be responsible for the decrease in freeness.
EXAMPLE 2
A 15 run response surface design (Table II) was performed in which the effect of a cationic (Cationic A) polymer followed by an anionic (Anionic B) polymer, in the presence and in the absence of Liftase A40, on the freeness of pulp was investigated. The pulp slurry of 2.3% consistency (3 g. dry weight) was first treated for 60 min. at 40° C. under continuous agitation (250 rpm) with an enzyme solution containing Liftase-A40 (0 to 0.4% based on dry weight of pulp), and then treated sequentially for 2.0 min. with different concentrations of Cationic A (0.2 to 2.0 pounds polymer as product actives/ton dry pulp) and Anionic B (0.28 0.84 pounds polymer as product actives/ton dry pulp). In many applications, 1 to 3 pounds of Cationic A as product are used. A higher dose (4.5 pounds) of Cationic A was tested since a colloid titration of the pulp revealed that 4.5×10 3 g of Cationic A polymer was required to satisfy the cationic demand of 3 g. (dry wt.) pulp used in this study. The freeness of the pulp decreased when treated with the anionic polymer alone, whereas the freeness increased when treated with the cationic polymer alone. It appears that the negative charges on the fiber prevent the adsorption of anionic polymers which remain solution.
Interestingly, with a sequential treatment of cationic and anionic polymers, the freeness of pulp was increased dramatically and a positive interaction between the two polymers has been found, particularly at high dosages of both polymers. Although a maximum increase in freeness may be achieved using high dosages of cationic and anionic polymers without enzyme, these unrealistically high dosages of polymers may be detrimental to the strength and the formation of the sheet.
TABLE II__________________________________________________________________________EXPERIMENTAL DESIGN: LIFTASE TESTED WITH CATIONIC & ANIONIC POLYMERS CAT: CATIONIC A AN: ANIONIC FREENESS MLRUNS DOSE* DOSE** ENZYME DOSE *** RUN ORDER (CSF)__________________________________________________________________________1 0.5 1 .2 12 2682 4.5 1 .2 14 4353 0.5 3 .2 2 2734 4.5 3 .2 17 6085 0.5 1 .4 11 3386 4.5 1 .4 7 4757 0.5 3 .4 4 2858 4.5 3 .4 8 6239 2.5 2 .3 5 31710 2.5 2 .3 9 32211 2.5 2 .3 1 31812 0 0 0 6 22213 2.5 0 0 3 23614 0 2 0 10 19015 0 0 .3 15 342__________________________________________________________________________ * = CATIONIC A DOSE (POUNDS PRODUCT/TON DRY PULP ** = ANIONIC DOSE (POUNDS PRODUCT/TON DRY PULP *** = % LIFTASE DOSE ON DRY WT. BASIS OF PULP
EXAMPLE 3
In order to confirm the positive interaction of cationic and anionic polymers another experimental design was carried out, where the interactions between lower dosages of polymers in the presence and in the absence of enzyme were investigated.
A 10 run response surface design (Table III) was carried out.
TABLE III______________________________________LIFTASE TESTED WITH DUAL POLYMER CATI- AN- EN- ONIC A IONIC B ZYME RUN FREENESSRUNS DOSE* DOSE** DOSE** ORDER ML (CSF)______________________________________1 0.5 0.5 .10 3 2822 3.0 0.5 .10 4 4553 0.5 3.0 .10 8 2404 3.0 3.0 .10 6 5975 0.5 0.5 .40 7 3656 3.0 0.5 .40 1 4977 0.5 3.0 .40 10 3238 3.0 3.0 .40 2 6629 1.8 1.8 .25 9 40510 1.8 1.8 .25 5 410______________________________________ * = CATIONIC A AND ANIONIC B DOSE (POUNDS PRODUCT/TON DRY PULP) ** = LIFTASE DOSE (% BASED ON DRY WT. OF PULP) *** = LIFTASE DOSE ON DRY WT. BASIS OF PULP
In this experiment, the effects of cationic (Cationic A) and anionic (Anionic B) polymers ranging from 0.22-1.33 pounds active/ton dry pulp (Cationic) and 0.14-0.84 pounds active/ton dry pulp (Anionic) in the presence and in the absence of Liftase A40, on the freeness of pulp was investigated. The pulp slurry and all the experimental conditions were similar to those described in Examples 1 and 2. In this experiment, the main effects of cationic and anionic polymers and enzyme were separately calculated using their low and high dosages over the entire combinations used in this experimental design. The results show that the presence of high dose of cationic polymer played a more dominant role in the increase of freeness (553 ml) than played by enzyme (462 ml) and anionic polymer (455 ml). Interactions between cationic and annionic polymers, cationic polymer and enzyme, and anionic polymer and enzyme were also investigated. A positive strong interaction has been found between cationic and anionic polymers. As found earlier, the cationic polymer played an important role in enhancing the freeness of pulp. In contrast, anionic polymer alone decreased the freeness. It is therefore important to use either high dosages of both cationic and anionic polymers or, if a low dose of cationic polymer is required, then the anionic polymer dose should also be kept low. A weak interaction has been found between cationic polymer and enzyme. No interaction has been found between anionic polymer and enzyme.
TABLE IV__________________________________________________________________________Least Squares Coefficients, Response CSF, Model0 Term 1 Coeff. 2 Std. Error 3 T-Value 4 Signif.__________________________________________________________________________1 1 401.259615 4.442421 90.32 0.00012 ˜C 125.125000 2.216768 56.44 0.00033 ˜A 27.875000 2.216768 12.57 0.00634 ˜E 34.125000 2.216768 15.39 0.00425 ˜C*A 48.875000 2.216768 22.05 0.00216 ˜C*E -7.375000 2.216768 -3.33 0.07977 ˜A*E 2.875000 2.216768 1.30 0.32418 CURVATURE 26.365385 4.966378 5.31 0.0337__________________________________________________________________________0 Term 5 Transformed Term__________________________________________________________________________1 12 ˜C ((C-1.75)/1.25)3 ˜A ((A-1.75)/1.25)4 ˜E ((E-2.5e-01)/1.5e-01)5 ˜C*A ((C-1.75)/1.25)*((A-1.756 ˜C*E ((C-1.75)/1.25)*((E-2.5e7 ˜A*E ((A-1.75)/1.25)*((E-2.5e8 CURVA ((C-1.75)/1.25)**2__________________________________________________________________________ No. cases = 10 Rsq. = 0.9995 RMS Error = 6.27 Resid. df = 2 Rsq-adj. = 0.9978 Cond. No. = 4.246 ˜ indicates factors are transformed.
The experimental data given in Table V was used to develop a predictive equation which was used to generate contour plots (FIGS. 3, 4, and 5). It is clearly shown (FIGS. 3, 4, and 5) that by increasing the enzyme dose from 0.1 to 0.4% the freeness increased and the shape of the curves of response surface changed. A dual polymer program with enzyme may be beneficial if the dosages level of polymers are correctly determined.
EXAMPLE 4
In order to broaden the scope of this investigation other cationic polymers such as poly-DADMAC (poly-DADMAC cationics) EDC-ammonia (EDC-Anionic/cationics) with an anionic (Anionic B) polymer in the presence of Liftase-A40 were also examined.
Experiments of a six run and a twelve run response surface design were carried out (Tables V and VI).
TABLE V__________________________________________________________________________0 1 RUN ORDER 2 CATIONIC-TYPE 3 CATIONIC-DOSE 4 ANIONIC-DOSE 5 NET-FREENESS__________________________________________________________________________1 3 CATIONIC A 0.50 0.50 2662 4 CATIONIC A 1.75 1.75 3823 6 CATIONIC A 0.50 3.00 2264 11 CATIONIC A 3.00 0.50 4555 12 CATIONIC A 3.00 3.00 6426 17 CATIONIC A 1.75 1.75 387__________________________________________________________________________
TABLE VI__________________________________________________________________________0 1 ORD 2 CATIONIC-TYPE 3 CATIONIC-DOSE 4 ANIONIC-DOSE 5 NET-FREENESS__________________________________________________________________________1 1 CATIONIC B 1.75 1.75 2522 2 CATIONIC C 0.50 0.50 266 (EDC-AMMONIA)3 5 CATIONIC B 0.50 3.00 2274 7 CATIONIC B 3.00 0.50 2795 8 CATIONIC C 1.75 1.75 245 (EDC-AMMONIA)6 9 CATIONIC C 0.50 3.00 224 (EDC-AMMONIA)7 10 CATIONIC C 3.00 0.50 258 (EDC-AMMONIA)8 13 CATIONIC C 3.00 3.00 240 (EDC-AMMONIA)9 14 CATIONIC B 3.00 3.00 25010 15 CATIONIC C 1.75 1.75 248 (EDC-AMMONIA)11 16 CATIONIC B 0.50 0.50 28212 18 CATIONIC B 1.75 1.75 256__________________________________________________________________________
The effect of cationic polymer Cationic A, was studied in the six-run design. Cationic polymers, poly-DADMAC B and EDC - ammonia C were studied using the twelve run design. Both experiments were run with an anionic polymer (Anionic B) in the presence of Liftase-A40 and the pulp freeness was measured. In each case the pulp slurry was first treated under optimal conditions with Liftase-A40 (0.2% based on dry weight of pulp), and then treated sequentially for 2.0 min. at 20° C. with different dosages of cationic polymers (0.5 to 3 pounds polymer as product/ton dry pulp) and an anionic polymer (0.5 to 3.0 pounds polymer as product/ton dry pulp).
These equations were then used to generate contour plots (FIGS. 6, 7, and 8). FIG. 6 shows that when both Cationic A and Anionic B dosages increased beyond one pound product/ton dry pulp, the freeness of pulp began to increase dramatically. At high dosages of each cationic and anionic polymer (3.0 pounds each polymer as product/ton dry pulp) the freeness increased from 202 mL to 642 mL. FIGS. 7 and 8 show no significant increase in freeness when the dosages of each cationic polymer (B and C) and anionic polymer (Anionic B) increased to 3.0 pounds polymer as product/ton dry pulp.
These results could be due to either differences in the chemistries of cationic polymers or lower polymer actives (15%) in B and C respectively, versus 45% in A.
EXAMPLE 5
To explain the results of Example 4, a separate experiment as described below was carried out. In this experiment, the performance of these polymers was investigated at equal polymer active basis. An eighteen-run response surface design (Table VII) was performed in which the effect of varying the chemistry of the cationic polymers (A, B, and C) and Anionic polymer B in the presence of Liftase-A40, on the freeness of pulp was investigated. The pulp slurry was first treated under optimal conditions with Liftase-A40 (0.2% based on dry weight of pulp) and then treated sequentially for 2.0 min. at 20° C. with equal active dosages of cationic polymers (0.225 to 1.350 pounds polymer/ton dry pulp) and an anionic polymer (Anionic B, 0.225 to 1.35 pound/polymer/ton dry pulp). The experimental data given in Table VII was used to develop a predictive equation which was used to generate contour plots (FIGS. 9, 10, and 11).
TABLE VII__________________________________________________________________________Evaluation of Dual Polymer Program Using Equal Actives 2 Cationic 3 Cationic 4 Anionic0 1 Ord Type Dose As Active Dose As Active 5 CSF__________________________________________________________________________ 1 1 CATIONIC B 0.675 0.675 368 2 2 CATIONIC C (EDC-AMMONIA) 0.225 0.225 268 3 3 CATIONIC A 0.225 0.225 266 4 4 CATIONIC A 0.675 0.675 330 5 5 CATIONIC B 0.225 1.350 250 6 6 CATIONIC A 0.225 1.350 238 7 7 CATIONIC B 1.350 0.225 388 8 8 CATIONIC C (EDC-AMMONIA) 0.675 0.675 366 9 9 CATIONIC C (EDC-AMMONIA) 0.225 1.350 23110 10 CATIONIC C (EDC-AMMONIA) 1.350 0.225 41211 11 CATIONIC A 1.350 0.225 40812 12 CATIONIC A 1.350 1.350 60013 13 CATIONIC C (EDC-AMMONIA) 1.350 1.350 57514 14 CATIONIC B 1.350 1.350 55515 15 CATIONIC C (EDC-AMMONIA) 0.675 0.675 36316 16 CATIONIC B 0.225 0.225 26017 17 CATIONIC A 0.675 0.675 33518 18 CATIONIC B 0.675 0.675 365__________________________________________________________________________
It is shown (FIGS. 9, 10 and 11) that when both cationic and anionic polymer dosages increased beyond 0.45 pounds active polymer/ton dry pulp the freeness of pulp began to increase dramatically. At high dosages (1.35 pounds active polymer/ton dry pulp) of cationic polymers (A, B and C) and anionic polymer (Anionic B) the freeness increased from 202 ml (control) to 600, 555 and 575 ml respectively. The shape and the trends of contour plots generated for each cationic polymer with Anionic B were so similar that they could be easily superimposed. These results suggested that different dual polymer programs can be used with enzyme for achieving high freeness of recycled fiber.
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A process for improving the freeness of paper pulp, which comprises the steps of adding to the pulp at least 0.05%, based on the dry weight of the pulp, of a cellulolytic enzyme, allowing the pulp to contact the cellulolytic enzyme for from about 40 minutes to about 60 minutes at a temperature of at least 40° C., adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic or nonionic polymer and forming the thus treated pulp into paper.
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TECHNICAL FIELD
[0001] The present disclosure relates in general to storage and processing of data, and more particularly to migrating stored data from one storage resource to another.
BACKGROUND
[0002] As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
[0003] Information handling systems often use one or more arrays of physical storage resources, for storing information. Arrays of physical storage resources typically utilize multiple disks to perform input and output operations and can be structured to provide redundancy which may increase fault tolerance (e.g., a Redundant Array of Independent Disks or “RAID”). Other advantages of arrays of storage resources may be increased data integrity, throughput, and/or capacity. In operation, one or more physical storage resources disposed in an array of storage resources may appear to an operating system as a single logical storage unit or “virtual storage resource.” Implementations of storage resource arrays can range from a few storage resources disposed in a server chassis, to hundreds of storage resources disposed in one or more separate storage enclosures. In certain cases, one or more arrays of storage resources may be implemented as a storage area network (SAN). A SAN is in effect an array or collection of physical storage resources communicatively coupled to and accessible via a network (e.g., a host information handling system may access the SAN via a network connection).
[0004] From time to time, an administrator or user of an array of storage resources may desire to migrate data from one storage resource to another. For example, as a storage resource ages and becomes obsolete, it may be desired to copy all of the data from the storage resource to a newer storage resource. However, traditional approaches to data migration have numerous disadvantages. For example, FIG. 1 depicts a system 100 employing a traditional approach to data migration. In the approach depicted in FIG. 1 , a migration module 104 on host 102 may manage migration of data from storage resource 110 a of storage array 108 a to storage array 108 b. Under this approach, capacity is allocated to the destination storage array 108 b (e.g., storage resource 110 b is allocated to storage array 108 b ), and destination storage resource 110 b is assigned an identifier (e.g., iSCSI qualified name or Fibre Channel World Wide Name) different than that of the source storage resource 110 a. Migration module 104 then reads the data from source storage resource 110 a and writes it to destination storage resource 110 b such that migrated data follows path 116 . During migration, a portion of the data being migrated may be the target of an input-output (I/O) operation (e.g., a read request or write request from host 102 ). Accordingly, under the approach of FIG. 1 , data associated with write requests may be written to both source storage resource 110 a and destination storage resource 110 b, and the migration module 104 may track which blocks have been written, so as to avoid writing old data over new data during the migration. Data associated with read requests during migration may be read from source storage resource 110 a. After all migrated data is copied to destination storage resource 110 b, migration module 104 may reconfigure host 102 to map to the destination storage resource 110 b, and source storage resource 110 a may be deleted.
[0005] The approach of FIG. 1 has numerous disadvantages. For example, the approach of FIG. 1 is inefficient because migrated data moves over network 106 twice (first from source storage resource 110 a to host 102 , then from host 102 to destination storage resource 110 b ). In addition, the approach of FIG. 1 requires that data associated with write requests be written to both source storage resource 110 a and destination storage resource 110 b during migration. Furthermore, this approach comes with a high level of management complexity, as destination storage resource 110 b is assigned a new identifier, requiring reconfiguration at the host level, network level, and the storage array level.
[0006] As another example, FIG. 2 depicts a system 200 employing a traditional approach to data migration. In the approach depicted in FIG. 2 , a replication module 214 on storage array 208 a may manage migration of data from storage resource 210 a of storage array 208 a to storage array 208 b. Under this approach, capacity is allocated to the destination storage array 208 b (e.g., storage resource 210 b is allocated to storage array 208 b ), and destination storage resource 210 b is assigned an identifier (e.g., iSCSI qualified name or Fibre Channel World Wide Name) different than that of the source storage resource 210 a. Replication module 214 then reads the data from source storage resource 210 a and writes it to destination storage resource 210 b via network 206 such that migrated data follows path 216 . Replication module 214 may use periodic snapshot technology to take periodic point in time snapshots to allow it to maintain a consistent copy of data for migration and allow it to track writes to source storage resource 210 a during migration of data to destination storage resource 210 b. Accordingly, under the approach of FIG. 2 , data associated with write requests may be tracked using the snapshot technology. Initially, data written by host 102 during migration may be written to source storage resource 210 a if blocks associated with such data have not been migrated, and may replication module 314 may also track writes using snapshot technology. At a certain point (e.g., if the number of blocks written by host 102 becomes small), replication module 214 may block I/O commands from host 102 , complete data migrations, and then reconfigure host 102 to access the new storage resource 110 b.
[0007] The approach of FIG. 2 also has numerous disadvantages. For example, the approach of FIG. 2 is inefficient because all write requests must be tracked with snapshots, which may be quite voluminous during times of heavy write activity. In addition, this approach comes with a high level of management complexity, as destination storage resource 210 b is assigned a new identifier, requiring reconfiguration at the host level and the storage array level.
SUMMARY
[0008] In accordance with the teachings of the present disclosure, the disadvantages and problems associated with data migration have been substantially reduced or eliminated.
[0009] In accordance with an embodiment of the present disclosure, a method for migration of data is provided. The method may include allocating a destination storage resource to receive migration data. The method may also include assigning the destination storage resource a first identifier value equal to an identifier value associated with a source storage resource. The method may additionally include assigning the source storage resource a second identifier value different than the first identifier value. The method may further include migrating data from the source storage resource to the destination storage resource.
[0010] In accordance with another embodiment of the present disclosure, a system for migration of data, may include a source storage resource, a destination storage resource, and a migration module configured to manage migration of data from the source storage resource to the destination storage resource. The migration module may be operable to, in response to a request to migrate data: (i) assign the destination storage resource a first identifier value equal to an identifier value associated with the source storage resource; (ii) assign the source storage resource a second identifier value different than the first identifier value; and (iii) migrate data from the source storage resource to the destination storage resource.
[0011] In accordance with a further embodiment of the present disclosure, a system for migration of data may include a source storage array comprising a source storage resource and a destination storage array. The destination storage array may be configured to: (i) allocate a destination storage resource to receive migration data from the source storage resource; (ii) assign the destination storage resource a first identifier value equal to an identifier value associated with the source storage resource; (iii) assign the source storage resource a second identifier value different than the first identifier value; and (iv) migrate data from the source storage resource to the destination storage resource.
[0012] Other technical advantages will be apparent to those of ordinary skill in the art in view of the following specification, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
[0014] FIG. 1 illustrates a block diagram of an approach to data migration, as is known in the art;
[0015] FIG. 2 illustrates a block diagram of another approach to data migration, as is known in the art;
[0016] FIG. 3 illustrates a block diagram of an example system for migrating data, in accordance with certain embodiments of the present disclosure;
[0017] FIG. 4 illustrates a flow chart of an example method for migrating data, in accordance with certain embodiments of the present disclosure;
[0018] FIG. 5 illustrates a flow chart of an example method for performing a read request, in accordance with certain embodiments of the present disclosure; and
[0019] FIG. 6 illustrates a flow chart of an example method for performing a write request, in accordance with certain embodiments of the present disclosure.
DETAILED DESCRIPTION
[0020] Preferred embodiments and their advantages are best understood by reference to FIGS. 3-6 , wherein like numbers are used to indicate like and corresponding parts.
[0021] For the purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an information handling system may be a personal computer, a PDA, a consumer electronic device, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include memory, one or more processing resources such as a central processing unit (CPU) or hardware or software control logic. Additional components or the information handling system may include one or more storage devices, one or more communications ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communication between the various hardware components.
[0022] For the purposes of this disclosure, computer-readable media may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Computer-readable media may include, without limitation, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing.
[0023] For the purposes of this disclosure, a processor may include any system, device, or apparatus configured to interpret and/or execute program instructions and/or process data, and may include, without limitation a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data.
[0024] For the purposes of this disclosure, a memory may include any system, device, or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). Memory may include random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), a PCMCIA card, flash memory, magnetic storage, opto-magnetic storage, or any suitable selection and/or array of volatile or non-volatile memory that retains data after power the memory is turned off.
[0025] For the purposes of this disclosure, a network interface may include any suitable system, apparatus, or device operable to serve as an interface between an information handling system and a network using any suitable transmission protocol and/or standard.
[0026] An information handling system may include or may be coupled via a network to one or more arrays of physical storage resources. An array of physical storage resources may include a plurality of storage resources, and may be operable to perform one or more input and/or output storage operations, and/or may be structured to provide redundancy. In operation, one or more storage resources disposed in an array of storage resources may appear to an operating system as a single logical storage unit or “virtual storage resource.”
[0027] In certain embodiments, an array of storage resources may be implemented as a Redundant Array of Independent Disks (also referred to as a Redundant Array of Inexpensive Disks or a RAID). RAID implementations may employ a number of techniques to provide for redundancy, including striping, mirroring, and/or parity checking. As known in the art, RAIDs may be implemented according to numerous RAID standards, including without limitation, RAID 0, RAID 1, RAID 0+1, RAID 3, RAID 4, RAID 5, RAID 6, RAID 01, RAID 03, RAID 10, RAID 30, RAID 50, RAID 51, RAID 53, RAID 60, RAID 100, etc.
[0028] FIG. 3 illustrates a block diagram of an example system 300 for migrating data, in accordance with certain embodiments of the present disclosure. As depicted, system 300 may include one or more hosts 302 , a network 306 , and one or more storage arrays 308 each comprising one or more storage resources 310 .
[0029] Host 302 may comprise an information handling system and may generally be operable to communicate via network 306 to read data from and/or write data to one or more storage resources 310 of storage arrays 308 . In certain embodiments, host 302 may be a server. In another embodiment, host 302 may be a personal computer (e.g., a desktop computer or a portable computer). Host 302 may include any suitable components (e.g., one or more processors, one or more memories, and one or more network interfaces to communicatively couple host 302 to network 306 . Although system 300 is depicted as having one host 302 for purposes of exposition, it is understood that system 300 may include any number of hosts 302 .
[0030] Network 306 may be a network and/or fabric configured to couple host 302 to one or more of storage arrays 308 . In certain embodiments, network 306 may allow host 302 to communicatively couple to storage resources 310 such that the storage resources 310 appear to host 302 as locally attached storage resources. In the same or alternative embodiments, network 306 may include a communication infrastructure, which provides physical connections, and a management layer, which organizes the physical connections, storage resources 310 , and host 302 . In the same or alternative embodiments, network 306 may allow block I/O services and/or file access services to storage resources 310 . Network 306 may be implemented as, or may be a part of, a storage area network (SAN), personal area network (PAN), local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a wireless local area network (WLAN), a virtual private network (VPN), an intranet, the Internet, or any other appropriate architecture or system that facilitates the communication of signals, data, and/or messages (generally referred to as data). Network 306 may transmit data using any storage and/or communication protocol, including without limitation, Fibre Channel, Frame Relay, Asynchronous Transfer Mode (ATM), Internet protocol (IP), other packet-based protocol, small computer system interface (SCSI), advanced technology attachment (ATA), serial ATA (SATA), advanced technology attachment packet interface (ATAPI), serial storage architecture (SSA), integrated drive electronics (IDE), and/or any combination thereof. Network 306 and its various components may be implemented using hardware, software, or any combination thereof.
[0031] Each storage array 308 may include any collection or array of storage resources 310 . Storage resources 310 may include hard disk drives, magnetic tape libraries, optical disk drives, magneto-optical disk drives, compact disk drives, compact disk arrays, disk array controllers, and/or any other system, apparatus or device operable to store data. In some embodiments, one or more of storage resources 310 may comprise a physical storage resource. In the same or alternative embodiments, one or more of storage resources 310 may comprise a virtual storage resource, wherein such virtual storage resource includes a collection of one or more physical storage resources that may appear to host 302 as a single storage resource. Although not depicted in FIG. 3 , storage enclosures may be configured to hold and power one or more storage resources 310 , and may be communicatively coupled to host 302 and/or network 306 , in order to facilitate communication of data between host 302 and storage resources 310 . In certain embodiments, one or more storage arrays 310 may be coterminous with a storage enclosure.
[0032] As depicted in FIG. 3 , storage array 308 b may include a migration module 314 . Migration module 314 may include any system, device, or apparatus configured to manage migration of data between storage resources 310 in accordance with this disclosure and as described in greater detail elsewhere in this disclosure. In certain embodiments, all or a portion of migration module 314 may be implemented in hardware. In the same or alternative embodiments, all or a portion of migration module 314 may be implemented in software and/or firmware embodied in a computer-readable medium.
[0033] Also as shown in FIG. 3 , migration module 314 may include a counter 318 and a bitmap 320 . Counter 318 may include any system, device, or apparatus configured to track the amount of data migrated from one storage resource 310 to another storage resource 310 (e.g., from storage resource 310 a to storage resource 310 b ) in accordance with this disclosure and as described in greater detail elsewhere in this disclosure. In certain embodiments, all or a portion of counter 318 may be implemented in hardware. In the same or alternative embodiments, all or a portion of counter 318 may be implemented in software and/or firmware embodied in a computer-readable medium.
[0034] Bitmap 320 may include any system, device, or apparatus configured to track the blocks of a storage resource 310 written to pursuant to an input-output operation during migration (e.g., a write request from host 302 to a destination storage resource 310 during migration) in accordance with this disclosure and as described in greater detail elsewhere in this disclosure. In certain embodiments, all or a portion of bitmap 320 may be implemented in hardware. In the same or alternative embodiments, all or a portion of bitmap 320 may be implemented in software and/or firmware embodied in a computer-readable medium.
[0035] Although the embodiment shown in FIG. 3 depicts system 300 having two storage arrays 308 for the purposes of exposition, system 300 may have any suitable number of storage arrays 308 . In addition, although the embodiment shown in FIG. 3 depicts each storage array 308 having one storage resource 310 for the purposes of exposition, each storage array 308 of network 300 may have any suitable number of storage resources 310 .
[0036] Although FIG. 3 depicts host 302 communicatively coupled to storage arrays 308 via network 306 for purposes of exposition, one or more hosts 302 may be communicatively coupled to one or more storage resources 310 without network 306 or other network. For example, in certain embodiments, one or more storage resources 310 may be directly coupled and/or locally attached to one or more hosts 302 .
[0037] FIG. 4 illustrates a flow chart of an example method 400 for migrating data, in accordance with certain embodiments of the present disclosure. According to one embodiment, method 400 preferably begins at step 402 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 300 . As such, the preferred initialization point for method 400 and the order of the steps 402 - 420 comprising method 400 may depend on the implementation chosen.
[0038] At step 402 , a message may be communicated requesting migration of data from source storage resource 310 a to storage array 308 b. For example, the message may be communicated as a result of a command issued by an administrator or user of system 300 . In some embodiments, the message may be communicated from host 302 to storage array 308 a or storage array 308 b. In other embodiments, an administrator may issue the command from an information handling system or terminal other than host 302 .
[0039] At step 404 , migration module 314 of storage array 308 b may receive the message from host 302 .
[0040] At step 406 , in response to receipt of the migration request message, storage array 308 b may allocate storage resource 310 b as the migration destination and assign it the same identifier value as source storage resource 310 a (e.g, iSCSI qualified name or FibreChannel World Wide Name).
[0041] At step 408 , storage array 308 a may instruct host 302 to redirect all input/output requests for source storage resource 310 a to destination storage resource 310 b. For example, in SCSI embodiments, storage array 308 a may respond to an input/output request from host 302 intended for source storage resource 310 a by responding to host 302 with a REDIRECT message.
[0042] At step 410 , storage array 308 a or another suitable component of system 300 may change the identifier of source storage resource 310 a to an identifier value unknown by host 302 , but known to migration module 314 (e.g, iSCSI qualified name or FibreChannel World Wide Name).
[0043] At step 411 , migration module 314 may initiate counter 318 (e.g., reset counter 318 or set it to zero).
[0044] At step 412 , migration module 314 may determine whether data in a particular block of storage resource 310 a has already been replaced by a write operation to destination storage resource 310 b that has occurred during the migration process. For example, migration module 314 may determine the memory address of the data block and compare the memory address with bitmap 320 to determine whether the bitmap 320 entry corresponding with the memory address indicates that a write operation corresponding to the memory address has been performed. If the data in the block has already been replaced by a write operation, method 400 may proceed to step 418 . Otherwise, if the data in the block has not been replaced by a write operation, method 400 may proceed to step 414 .
[0045] At step 414 , in response to a determination that the data block has not been replaced by a write operation, migration module 314 may read a block of data from storage resource 310 a, by addressing source storage resource 310 a with its new private identifier.
[0046] At step 416 , migration module may write the block to destination storage resource 310 b.
[0047] At step 418 , in response to the data block written to destination storage resource 310 b or in response to a determination that the data block has already been replaced by a write operation, migration module 314 may increment counter 318 to indicate the block has been written.
[0048] At step 420 , migration module 314 may determine if all data associated with the migration has been migrated. For example, migration module 314 may compare the value present in counter 318 (e.g., indicating the number of data blocks migrated) to a value indicative of the amount of data to be migrated (e.g., the number of blocks present in source storage resource 310 a ). If not all data associated with the migration has migrated, method 400 may proceed again to step 412 , where another block of data may be read from source storage resource 310 a. If all data associated with the migration has been migrated, method 400 may end.
[0049] Although FIG. 4 discloses a particular number of steps to be taken with respect to method 400 , method 400 may be executed with greater or lesser steps than those depicted in FIG. 4 . In addition, although FIG. 4 discloses a certain order of steps to be taken with respect to method 400 , the steps comprising method 400 may be completed in any suitable order. In addition, steps 402 - 420 may be repeated, independently and/or collectively, as often as desired or required by a chosen implementation.
[0050] Method 400 may be implemented using system 300 or any other system operable to implement method 400 . In certain embodiments, method 400 may be implemented partially or fully in software and/or firmware embodied in computer-readable media.
[0051] FIG. 5 illustrates a flow chart of an example method 500 for performing a read request during migration of data, in accordance with certain embodiments of the present disclosure. According to one embodiment, method 500 preferably begins at step 502 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 300 . As such, the preferred initialization point for method 500 and the order of the steps 502 - 516 comprising method 500 may depend on the implementation chosen.
[0052] At step 502 , storage array 308 b may receive a read request (e.g., from host 302 ) for destination storage resource 310 b while a migration operation (e.g., method 400 ) is taking place.
[0053] At step 504 , in response to receiving the read request, migration module 314 may determine whether the data associated with the read request has already been migrated to destination storage resource 310 b. For example, migration module 314 may compare the value present in counter 318 (e.g., indicating the number of data blocks migrated) to a value indicative of data associated with the read request (e.g., a block address associated with the read request), to determine whether the subject data has already been migrated. If the data associated with the read request has not been migrated to destination storage resource 310 b, method 500 may proceed to step 506 . Otherwise, if the data associated with the read request has been migrated to destination storage resource 310 b, method 500 may proceed to step 516 .
[0054] At step 506 , in response to a determination that the data associated with the read request has not been migrated to destination storage resource 310 b, migration module 314 may communicate the read request to source storage resource 310 a using the private identifier of the source storage resource 310 a.
[0055] At step 508 , in response to the read request received from migration module 314 , source storage resource 310 a may communicate to migration module 314 the data responsive to the read request.
[0056] At step 510 , migration module 314 may communicate (e.g., to host 302 ) data responsive to the read request.
[0057] At step 512 , migration module 314 may write the data responsive to the read request to storage resource 310 b. This step may reduce the number of data transfers over the network during migration, and future reads of the same data may be satisfied from storage resource 310 b.
[0058] At step 514 , migration module 314 may update bitmap 320 to indicate blocks of data that have been written to storage resource 310 b. After completion of step 514 , method 500 may end.
[0059] At step 516 , in response to a determination that the data associated with the read request has been migrated to destination storage resource 310 b, destination storage resource 310 b may communicate (e.g., to host 302 ) the data responsive to the read request. After completion of step 516 , method 500 may end.
[0060] Although FIG. 5 discloses a particular number of steps to be taken with respect to method 500 , method 500 may be executed with greater or lesser steps than those depicted in FIG. 5 . In addition, although FIG. 5 discloses a certain order of steps to be taken with respect to method 500 , the steps comprising method 500 may be completed in any suitable order. In addition, steps 502 - 510 may be repeated, independently and/or collectively, as often as desired or required by a chosen implementation.
[0061] Method 500 may be implemented using system 300 or any other system operable to implement method 500 . In certain embodiments, method 500 may be implemented partially or fully in software and/or firmware embodied in computer-readable media.
[0062] FIG. 6 illustrates a flow chart of an example method 600 for performing a write request during migration of data, in accordance with certain embodiments of the present disclosure. According to one embodiment, method 600 preferably begins at step 602 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 300 . As such, the preferred initialization point for method 600 and the order of the steps 602 - 606 comprising method 600 may depend on the implementation chosen.
[0063] At step 602 , storage array 308 b may receive a write request (e.g., from host 302 ) for destination storage resource 310 b while a migration operation (e.g., method 400 ) is taking place.
[0064] At step 604 , in response to the write request, storage array 308 b may store data associated with the write request on destination storage resource 310 b.
[0065] At step 606 , in response to the write request, migration module 314 may update bitmap 320 to indicate blocks of data that have been written pursuant to the write operation. After completion of step 606 , method 600 may end.
[0066] Although FIG. 6 discloses a particular number of steps to be taken with respect to method 600 , method 600 may be executed with greater or lesser steps than those depicted in FIG. 6 . In addition, although FIG. 6 discloses a certain order of steps to be taken with respect to method 600 , the steps comprising method 600 may be completed in any suitable order. In addition, steps 602 - 606 may be repeated, independently and/or collectively, as often as desired or required by a chosen implementation.
[0067] Method 600 may be implemented using system 300 or any other system operable to implement method 600 . In certain embodiments, method 600 may be implemented partially or fully in software and/or firmware embodied in computer-readable media.
[0068] In the discussion of methods 400 , 500 and 600 above, many references are made to “read requests,” “read operations,” “write requests,” ad “write operations.” For the purposes of this disclosure, such terms are used to broadly refer to any suitable read or write operation that may be issued or communicated in accordance with any suitable storage technique, protocol, and/or standard (e.g., Small Computer System Interface, Internet Small Computer System Interface, FibreChannel, etc.).
[0069] Using the methods and systems disclosed herein, problems associated with conventional approaches to data migration may be improved, reduced, or eliminated. For example, using the migration approaches set forth in this disclosure, migrated data and data stored pursuant to write operations may only be communicated over a network once, instead of twice as is the case with traditional approaches. In addition, host connections to a storage network are migrated automatically from the destination storage array and no reconfiguration of a host or network may be required to allow a host to access the destination storage resource.
[0070] Although the present disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and the scope of the disclosure as defined by the appended claims.
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Systems and methods for data migration are disclosed. A method may include allocating a destination storage resource to receive migration data. The method may also include assigning the destination storage resource a first identifier value equal to an identifier value associated with a source storage resource. The method may additionally include assigning the source storage resource a second identifier value different than the first identifier value. The method may further include migrating data from the source storage resource to the destination storage resource.
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[0001] This application is a Continuation of International Application No. PCT/US2007/074918 filed Aug. 1, 2007, which claims the benefit of U.S. Provisional Application Nos. 60/947,731 filed Jul. 3, 2007 and 60/915,761 filed May 3, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to granules and solid oral pharmaceutical dosage forms, suitably tablets, suitably capsules, comprising 3′-[(2Z)-[1-(3,4-dimethylphenyl)-1,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylidene]hydrazino]-2′-hydroxy-[1,1′-biphenyl]-3-carboxylic acid bis-(monoethanolamine) represented by the following formula (I) and hereinafter referred to as “eltrombopag olamine” or Compound B:
[0000]
BACKGROUND OF THE INVENTION
[0003] 3′-{N′-[1-(3,4-dimethylphenyl)-3-methyl-5-oxo-1,5-dihydropyrazol-4-ylidene]hydrazino}-2′-hydroxybiphenyl-3-carboxylic acid (hereinafter Compound A) is a compound which is disclosed and claimed, along with pharmaceutically acceptable salts, hydrates, solvates and esters thereof, as being useful as an agonist of the TPO receptor, particularly in enhancing platelet production and particularly in the treatment of thrombocytopenia, in International Application No. PCT/US01/16863, having an International filing date of May 24, 2001; International Publication Number WO 01/89457 and an International Publication date of Nov. 29, 2001; which has United States Publication Number US2004/0019190 A1, having a United States Publication date of Jan. 29, 2004; now U.S. Pat. No. 7,160,870, issued Jan. 9, 2007, the disclosure of which is hereby incorporated by reference.
[0004] The bis-(monoethanolamine) salt of this compound is disclosed (disclosed as 3′-[(2Z)-[1-(3,4-dimethylphenyl)-1,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylidene]hydrazino]-2′-hydroxy-[1,1′-biphenyl]-3-carboxylic acid, which also describes Compound A) in International Application No. PCT/US03/16255, having an International filing date of May 21, 2003; International Publication Number WO 03/098002 and an International Publication date of Dec. 4, 2003; which has United States Publication Number US2006/0178518 A1, having a United States Publication date of Aug. 10, 2006; the disclosure of which is hereby incorporated by reference.
[0005] Compound A is disclosed for the treatment of degenerative diseases/injuries in International Application No. PCT/US04/013468, having an International filing date of Apr. 29, 2004; International Publication Number WO 04/096154 and an International Publication date of Nov. 11, 2004; which has United States Publication Number US2007/0105824 A1, having a United States Publication date of May 10, 2007; the disclosure of which is hereby incorporated by reference.
[0006] Compositions that may contain Compound A and/or Compound B are disclosed in International Application No. PCT/US01/16863, International Application No. PCT/US03/16255 and International Application No. PCT/US04/013468.
[0007] Solid oral pharmaceutical dosage forms are popular and useful forms of medications for dispensing pharmaceutically active compounds. A variety of such forms are known, including tablets, capsules, pellets, lozenges, and powders.
[0008] However, the formulation of an acceptable solid oral pharmaceutical dosage form on a commercial scale is not always straightforward. The formula and process of manufacture must be such as to provide an integral solid dosage form that maintains its integrity until used. The solid dosage form must also possess acceptable dissolution and disintegration properties so as to provide the desired profile in use. Pharmaceutically active compounds with low solubility and/or that can react with commonly used excipients can present particular challenges in preparing high quality solid dosage forms, since the physical properties of the drug influence the properties of the solid dosage form. The formulator must balance the drug's unique properties with the properties of each excipient in order to prepare a safe, efficacious and easy to use solid dosage form.
[0009] Eltrombopag olamine presents the formulator with unique concerns when attempting to formulate this compound into a suitable solid oral pharmaceutical dosage form, suitably a tablet, suitably a capsule, with a desirable pharmacokinetic profile, particularly on a commercial scale. Such concerns include, but are not limited to; the tendency of the compound to form insoluble metal complexes when contacted with excipients that contain a coordinating metal, slow dissolution of the compound from solid dosage forms and the tendency of the compound to under go a Maillard reaction when contacted with excipients that contain reducing sugars. Significant realization of these concerns will have an adverse effect on the in vivo administration of eltrombopag olamine.
[0010] It would be desirable to provide eltrombopag olamine in a solid oral pharmaceutical dosage form on a commercial scale with a desirable pharmacokinetic profile.
[0011] The present invention is directed to granules and solid oral pharmaceutical dosage forms that contain eltrombopag olamine, suitably the solid dosage form is a tablet, suitably the solid dosage form is a capsule, suitably these solid dosage forms are produced on a commercial scale.
SUMMARY OF THE INVENTION
[0012] The present invention relates to granules and solid oral pharmaceutical dosage forms comprising a therapeutically effective amount of eltrombopag olamine. The invention also relates to a process for making granules and solid oral pharmaceutical dosage forms comprising eltrombopag olamine.
[0013] Another aspect of this invention relates to granules and solid oral pharmaceutical dosage forms, suitably tablets, suitably capsules, comprising eltrombopag olamine that are formulated using diluents that are substantially free of reducing sugars, which as used herein and in the claims includes diluents that are free of reducing sugars, and that are substantially free of coordinating metals, which as used herein and in the claims includes diluents that are free of coordinating metals. Such granules and solid oral pharmaceutical dosage forms exhibit improved properties. Such improved properties help to ensure safe and effective treatment.
[0014] Another aspect of this invention relates to film coated pharmaceutical tablets comprising eltrombopag olamine, wherein the film coat contains no coordinating metals, or only an amount of coordinating metal approximately equal to or less than 0.025 parts of Compound B. Such tablets exhibit improved properties. Such improved properties help to ensure safe and effective treatment.
[0015] Another aspect of this invention relates to granules and solid oral pharmaceutical dosage forms comprising eltrombopag olamine that are formulated with a defined drug particle size range where about 90% of drug particle size is in the range of 10 to 90 microns. Such tablets exhibit improved properties. Such improved properties help to ensure safe and effective treatment.
[0016] Another aspect of this invention relates to granules and solid oral pharmaceutical dosage forms containing eltrombopag olamine comprising a high percentage of disintegrant, suitably an amount equal to or greater than 4%. Such tablets exhibit improved properties. Such improved properties help to ensure safe and effective treatment.
[0017] Another aspect of this invention relates to a method of treating thrombocytopenia, which method comprises administering to a subject in need thereof a therapeutically effective amount of granules or a solid oral pharmaceutical dosage form of the present invention.
[0018] Another aspect of this invention relates to a method of agonizing the TPO receptor, which method comprises administering to a subject in need thereof a therapeutically effective amount of granules or a solid oral pharmaceutical dosage form of the present invention.
[0019] Also included in the present invention are methods of co-administering granules or a solid oral pharmaceutical dosage form of the present invention with further active ingredients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 depicts the dissolution comparison of tablets containing eltrombopag and a metal containing diluent with tablets containing eltrombopag and a non-metal containing diluent.
[0021] FIG. 2 depicts the effect of API particle size on the dissolution of eltrombopag from 75 mg tablets.
DETAILED DESCRIPTION OF THE INVENTION
[0022] By the term “coordinating metal” and “coordinating metals” and derivatives thereof, as used herein is meant a metal or a metal containing excipient, suitably a diluent, or metal containing tablet coating material, which forms a complex, such as a chelate complex, in the presence of eltrombopag olamine. Examples of such metals include:
[0023] aluminum, calcium, copper, cobalt, gold, iron, magnesium, manganese and zinc.
[0024] By the term “reducing sugar” as used herein is meant a sugar or sugar containing excipient, suitably a diluent, which reacts with eltrombopag olamine to form a Maillard product when admixed together. Examples of such reducing sugars include:
[0025] lactose, maltose, glucose, arabinose and fructose.
[0026] The term Maillard reaction is well known in the art and is utilized herein as to its standard meaning. Generally, the term Maillard reaction is used herein to mean the reaction of a reducing sugar, as defined herein, in a formulation, suitably granules or solid dosage forms, with eltrombopag olamine that produces a pigment or pigments, suitably a brown pigment. The pigments are referred to herein as Maillard products. The production of such Maillard products is an indication of chemical instability.
[0027] As used herein, the term “improved properties” and derivatives thereof, contemplates several advantages to the pharmacokinetic profile of the in vivo release of Compound B from a formulation, suitably granules or a solid oral pharmaceutical dosage form, that utilizes an aspect of the present invention when compared to a formulation that does not utilize that aspect of the present invention, suitably the formulation is produced on a commercial scale, and will vary depending on the particular aspect of the invention being utilized. Examples of improved properties include: increased oral bioavailability, reduced formation of insoluble metal complexes, improved chemical stability, a consistent pharmacokinetic profile and a consistent dissolution rate.
[0028] As used herein, the term “drug” or “active ingredient” and derivatives thereof, means Compound B or eltrombopag olamine.
[0029] By the term “commercial scale” and derivatives thereof, as used herein is meant, preparation of a batch scale greater than about 20 kg of granulation mix, suitably greater than 50 kg, suitably greater than 75 kg or a batch size suitable to prepare at least about 50,000 tablets, suitably at least 75,000 tablets, suitably at least 100,000 tablets.
[0030] When indicating that the diluents for use herein and in the claims are substantially free of coordinating metals and/or that are substantially free of reducing sugars, it is contemplated that minor amounts, for example: about 5% or less, of the diluent component could contain a coordinating metal or metals and/or a reducing sugar or reducing sugars. In this aspect of the invention, it is believed that very minor amounts of coordinating metals and/or reducing sugars can be incorporated into the diluent component without adversely effecting tablet performance.
[0031] The term “effective amount” and derivatives thereof, means that amount of a drug or active ingredient that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician. Furthermore, the term “therapeutically effective amount” means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function.
[0032] As used herein, the term “formulation” and derivatives thereof, unless otherwise defined refers to granules and/or solid oral pharmaceutical dosage forms of the invention that contain eltrombopag olamine.
[0033] By the term “co-administering” and derivatives thereof as used herein is meant either simultaneous administration or any manner of separate sequential administration of granules and/or a solid oral pharmaceutical dosage form of the present invention and a further active ingredient or ingredients, known to treat thrombocytopenia, including chemotherapy-induced thrombocytopenia and bone marrow transplantation and other conditions with depressed platelet production. The term further active ingredient or ingredients, as used herein, includes any compound or therapeutic agent known to or that demonstrates advantageous properties when administered with TPO or a TPO mimetic. Preferably, if the administration is not simultaneous, the compounds are administered in a close time proximity to each other. Furthermore, it does not matter if the compounds are administered in the same dosage form, e.g. one compound may be administered topically and another compound may be administered orally.
[0034] Examples of a further active ingredient or ingredients for use in combination with the presently invented formulations include but are not limited to: chemoprotective or myeloprotective agents such as G-CSF, BB11000 (Clemons et al., Breast Cancer Res. Treatment, 1999, 57, 127), amifostine (Ethyol) (Fetscher et al., Current Opinion in Hemat., 2000, 7, 255-60), SCF, IL-11, MCP-4, IL-1-beta, AcSDKP (Gaudron et al., Stem Cells, 1999, 17, 100-6), TNF-a, TGF-b, MIP-1a (Egger et al., Bone Marrow Transpl., 1998, 22 (Suppl. 2), 34-35), and other molecules identified as having anti-apoptotic, survival or proliferative properties.
[0035] By the term “granules” and derivatives thereof, as used herein refers to formulated particles that comprise eltrombopag olamine, diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and suitably also binders and/or lubricants and/or disintegrants such that the particles are suitable for utilization in preparing solid oral pharmaceutical dosage forms. It is also possible to administer the granules directly to a subject in need thereof as a medicament. However, it is anticipated that the granules are most appropriately utilized in the preparation of solid oral pharmaceutical dosage forms as indicated above.
[0036] By the term “solid oral pharmaceutical dosage form” and “solid dosage form” and derivatives thereof, as used herein refers to a final pharmaceutical preparation that comprises eltrombopag olamine, such tablets, capsules, pellets, lozenges and powders (including coated versions of any of such preparations) that are suitable for in vivo administration.
[0037] Suitably, the granules and solid oral pharmaceutical dosage forms of the present invention comprise eltrombopag olamine, a diluent (also known as filler or bulking agent), and suitably also a binder and/or a lubricant and/or a disintegrant. Those skilled in the art will recognize that a given material may provide one or more functions in the tablet formulation, although the material is usually included for a primary function. The percentages of diluent, binder, lubricant and disintegrant provided herein and in the claims are by weight of the tablet.
[0038] Diluents provide bulk, for example, in order to make the tablet a practical size for processing. Diluents may also aid processing, for example, by providing improved physical properties such as flow, compressibility, and tablet hardness. Because of the relatively high percentage of diluent and the amount of direct contact between the diluent and the active compound in the typical pharmaceutical formulation, the interaction of the diluent with the active compound is of particular concern to the formulator. Examples of diluents suitable for general use include: water-soluble fillers and water-insoluble fillers, such as calcium phosphate (e.g., di and tri basic, hydrated or anhydrous), calcium sulfate, calcium carbonate, magnesium carbonate, kaolin, spray dried or anhydrous lactose, cellulose (e.g., microcrystalline cellulose, powdered cellulose), pregelatinized starch, starch, lactitol, mannitol, sorbitol, maltodextrin, powdered sugar, compressible sugar, sucrose, dextrose, and inositol. The diluents that do not contain coordinating metals and diluents that are non-reducing sugars are suitable for tablets of the current invention. Suitable diluents for use in this invention include microcrystalline cellulose, powdered cellulose, pregelatinized starch, starch, lactitol, mannitol, sorbitol, and maltodextrin. Unsuitable diluents include calcium phosphate (e.g., di and tri basic, hydrated or anhydrous), calcium sulfate, calcium carbonate, magnesium carbonate, kaolin, and spray dried or anhydrous lactose. In one embodiment of the present invention, the diluent is composed of one or both of Mannitol and microcrystalline cellulose.
[0039] The granules and solid oral pharmaceutical dosage forms of the present invention typically comprise from about 25% to about 89%, of one or more diluents.
[0040] One aspect of the present invention comprises granules wherein the granules are formulated using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars.
[0041] One aspect of the present invention comprises solid oral pharmaceutical dosage forms wherein the solid dosage forms are formulated using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars.
[0042] One aspect of the present invention comprises pharmaceutical tablets, wherein the tablets are formulated using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars.
[0043] One aspect of the present invention comprises pharmaceutical capsules, wherein the capsules are formulated using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars.
[0044] Binders impart cohesive properties to the powdered material. Examples of binders suitable for use in the present invention include: starch (e.g., paste, pregelatinized, mucilage), gelatin, sugars (e.g., sucrose, glucose, dextrose, molasses, lactose, dextrin, xylitol, sorbitol), polymethacrylates, natural and synthetic gums (e.g., acacia, alginic acids and salts thereof such as sodium alginate, gum tragacanth, Irish moss extract, panwar gum, ghatti gum, guar gum, zein), cellulose derivatives [such as carboxymethyl cellulose and salts thereof, methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC) and ethyl cellulose (EC)], polyvinylpyrrolidone, Veegum, larch arabogalactan, polyethylene glycol, waxes, water, alcohol, magnesium aluminum silicate, and bentonites. In one embodiment of the present invention, the binder comprises polyvinylpyrrolidone (PVP).
[0045] The granules and solid oral pharmaceutical dosage forms of the present invention typically comprise up to about 8% binder. The formulations suitably comprise up to about 5%, suitably up to about 2% binder.
[0046] Lubricants are generally used to enhance processing, for example, to prevent adhesion of the formulation material to manufacturing equipment, reduce interparticle friction, improve rate of flow of the formulation, and/or assist ejection of the formulations from the manufacturing equipment. Examples of lubricants suitable for use in the present invention include: talc, stearates (e.g., magnesium stearate, calcium stearate, zinc stearate, palmitostearate), stearic acid, hydrogenated vegetable oils, glyceryl behanate, polyethylene glycol, ethylene oxide polymers (e.g., CARBOWAXes), liquid paraffin, sodium lauryl sulfate, magnesium lauryl sulfate, sodium oleate, sodium stearyl fumarate, DL-leucine, and silica derivatives (e.g., colloidal silicon dioxide, colloidal silica, pyrogenic silica, and hydrated sodium silicoaluminate). In one embodiment of the present invention, the lubricant comprises magnesium stearate.
[0047] The granules and solid oral pharmaceutical dosage forms of the present invention typically comprise up to about 2% lubricant. The formulations suitably comprise up to about 1.5%, suitably up to about 1% lubricant.
[0048] Disintegrants are employed to facilitate breakup or disintegration of the formulation after administration. Examples of disintegrants suitable for use in the present invention include: starches, celluloses, gums, crosslinked polymers, and effervescent agents, such as corn starch, potato starch, pregelatinized starch, modified corn starch, croscarmellose sodium, crospovidone, sodium starch glycolate, Veegum HV, methyl cellulose, microcrystalline cellulose, cellulose, modified cellulose gum (e.g., Ac-Di-Sol R), agar, bentonite, montmorillonite clay, natural sponge, cation exchange resins, ion exchange resins (e.g., polyacrin potassium), alginic acid and alginates, guar gum, citrus pulp, carboxymethylcellulose and salts thereof such as sodium lauryl sulfate, magnesium aluminum silicate, hydrous aluminum silicate, sodium bicarbonate in admixture with an acidulant such as tartaric acid or citric acid. In one embodiment of the present invention, the disintegrant is sodium starch glycolate.
[0049] The granules and solid oral pharmaceutical dosage forms of the present invention typically comprise an amount from 4% to about 12% disintegrant. The formulations suitably comprise from about 6% to about 10%, suitably from about 7% to 9% disintegrant.
[0050] The solid oral pharmaceutical dosage forms, suitably tablets, suitably capsules, of the present invention will typically be sized up to 1 gram, e.g., from about 0.01 gram to about 0.8 gram. These solid dosage forms typically comprise from about 5 mg to about 900 mg of eltrombopag olamine per dosage form. In suitable embodiments, the solid dosage forms comprise from about 5 to about 200 mg eltrombopag olamine (e.g., in an about 100-800 mg dosage form). Tablet formulations of the invention may have a variety of shapes, including diamond, modified capsule, modified oval, and hexagonal, and may optionally have a tilt.
Tablets
[0051] The choice of particular types and amounts of excipients, and tabletting technique employed depends on the further properties of eltrombopag olamine and the excipients, e.g., compressibility, flowability, particle size, compatibility, and density. The tablets may be prepared according to methods known in the art, including direct compression, dry granulation, fluid bed granulation, and wet granulation, and the type of excipients used will vary accordingly. It has been found that wet granulation is particularly suitable for providing high strength, low breakage tablets comprising relatively high concentrations of eltrombopag olamine (e.g., about 40% or more), on a scale suitable for commercial production. Suitable wet granulated tablets of the invention comprise granules comprising eltrombopag olamine and one or more of fillers, binders and disintegrants, wherein the granules are mixed with additional filler, binder, disintegrant and/or lubricant to form a compression mixture that is compressed to form tablets.
[0052] Included in the present invention are pharmaceutical compositions in tablet form, suitably prepared on a commercial scale, that comprise eltrombopag olamine, wherein the tablet is made by a wet granulation process using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars. Also included in the present invention are such pharmaceutical compositions that contain a film coat, wherein the film coat contains no coordinating metals, or only an amount of coordinating metal approximately equal to or less than 0.025 parts of Compound B.
[0053] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the tablet is made by a wet granulation process, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 90% of the eltrombopag olamine particles have a particle size greater than 10 micron but less than 90 micron.
[0054] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the tablet is made by a wet granulation process, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 90% of the eltrombopag olamine particles have a particle size greater than 10 micron but less than 90 micron, suitably greater than 20 micron but less than 50 micron.
[0055] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the tablet is made by a wet granulation process, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 50% of the eltrombopag olamine particles have a particle size greater than 5 micron but less than 50 micron, suitably greater than 5 micron but less than 20 micron.
[0056] In one embodiment of the present invention, the tablets of the present invention comprise:
(i) from about 2% to about 65% eltrombopag olamine; (ii) from about 25% to about 89% of diluent; (iii) up to about 8% binder, suitably up to about 5%, suitably up to about 4%; (iv) up to about 2% lubricant, suitably up to about 1.5%, suitably up to about 1%; and (v) from 4% to about 12% disintegrant, suitably 6% to 10%, suitably from 7% to 9%.
[0062] Suitable wet granulated tablets comprise, by weight of the tablet, from about 10% to about 95% of eltrombopag olamine active intragranules and from about 5% to about 90% of external excipients; wherein the eltrombopag olamine active intragranules comprise, by weight of the intragranules:
(i) from about 2% to about 88% eltrombopag olamine; (ii) from about 10% to about 96% diluent; (iii) from about 2% to about 5% binder; and (iv) optionally from 0% to about 4% disintegrant;
and wherein the external excipients comprise, by weight of the tablet:
(i) from 0% to about 70% diluent; (ii) from about 0.25% to about 2%, suitably from about 0.25% to about 1.25% lubricant; and (iii) from 4% to about 10% disintegrant.
[0070] In the foregoing embodiments, the diluent is suitably a combination of mannitol and microcrystalline cellulose, the non-reducing sugar is suitably mannitol, the binder is suitably polyvinylpyrolidone, the lubricant is suitably magnesium stearate, and the disintegrant is suitably sodium starch glycolate. Suitably, the intragranule filler is a mixture of mannitol and microcrystalline cellulose and the external filler is microcrystalline cellulose.
[0071] In one embodiment of the current invention, tablets are coated with a film coat formed from an aqueous film coat composition. Aqueous film coat compositions suitable for use in the present invention comprise a film-forming polymer, water as a vehicle, and optionally one or more adjuvants such as are known in the film-coating art. When the film coat contains a coordinating metal, as used herein, the amount of coordinating metal is approximately equal to or less than 0.025 parts of Compound B.
[0072] The film-forming polymer is selected to form coatings with mechanical properties (e.g., mechanical strength, flexibility) suitable to meet performance requirements, such as those required by the intended use environment (e.g., dissolution profile in gastrointestinal fluids), and/or use (e.g. solution viscosity). Examples of suitable film-forming polymers include cellulosic polymers (e.g., cellulose ethers such as HPMC, HPC, MC, EC, HEC, CAP, sodium ethyl cellulose sulfate, carboxymethyl cellulose and the like); polyvinylpyrolidone; zein; and acrylic polymers (e.g., methacrylic acid/methacrylic acid ester copolymers such as methacrylic acid/methylmethacrylate copolymers and the like). Cellulosic polymers are preferred in the present invention, especially cellulosic ethers and more especially HPMC and HPC. The polymers are typically provided in either aqueous or organic solvent based solutions or aqueous dispersions. However, the polymers may be provided in dry form, alone or in a powdery mixture with other components (e.g., a plasticizer and/or colorant), which is made into a solution or dispersion by the user by admixing with the aqueous vehicle.
[0073] The aqueous film coat composition further comprises water as a vehicle for the other components, to facilitate their delivery to the tablet surface. The vehicle may optionally further comprise one or more water soluble solvents, e.g., alcohols (e.g., methanol, isopropanol, propanol) and ketones (e.g., acetone). The skilled artisan can select appropriate vehicle components to provide good interaction between the film-forming polymer and the vehicle to ensure good film properties. In general, polymer-vehicle interaction is designed to yield maximum polymer chain extension to produce films having the greatest cohesive strength and thus mechanical properties. The components are also selected to provide good deposition of the film-forming polymer onto the tablet surface, such that a coherent and adherent film is achieved.
[0074] The aqueous film coating composition may optionally comprise one or more adjuvants known in the art, such as plasticizers, colorants, detackifiers, secondary film-forming polymers, flow aids, surfactants (e.g., to assist spreading), maltodextrin, and polydextrose.
[0075] Plasticizers provide flexibility to the film, which may reduce film cracking and improve adhesion to the tablet. Suitable plasticizers will generally have a high degree of compatibility with the film-forming polymer and sufficient permanence such that the coating properties are generally stable. Examples of suitable plasticizers include glycerin, propylene glycol, polyethylene glycols (e.g., molecular weight from 200 to 20,000, including Union Carbide's PEG 400, 4000, 6000, 8000, and 20,000), glycerin triacetate (aka triacetin), acetylated monoglyceride, citrate esters (e.g., triethyl citrate, acetyl triethyl citrate, tributyl citrate, acetyl tributyl citrate), phthalate esters (e.g., diethyl phthalate), mineral oil and hydrogenated glucose syrup. In one embodiment of the present invention, the plasticizer is chosen from polyethylene glycols, triacetin, propylene glycol, glycerin, and mixtures thereof.
[0076] The aqueous film coat composition suitably comprises one or more colorants. In addition to enhancing esthetic appeal, the colorant provides product identification. Suitable colorants include those approved and certified by the FDA, including FD&C and D&C approved dyes, lakes, and pigments, and titanium dioxide, provided that the film coat contains no coordinating metals, or only an amount of coordinating metal approximately equal to or less than 0.025 parts of Compound B.
[0077] Suitably, the colorant comprises one or more coloring agents selected from the group consisting of red iron oxides, red dyes and lakes, yellow iron oxides, yellow dyes and lakes, titanium dioxide, and indigo carmine. For example, the colorant may be selected to provide a light beige shade, for example consisting essentially of a) red iron oxide, red dye, and/or red lake, b) yellow iron oxide, yellow dye, and/or yellow lake, and c) titanium dioxide. Alternatively, the colorant may be selected to provide a pink shade (e.g., consisting essentially of titanium dioxide and red iron oxide, red dye and/or red lake); a light green shade (e.g., consisting essentially of yellow iron oxide, yellow dye and/or yellow lake, indigo carmine, and titanium dioxide); a light blue shade (e.g., consisting essentially of titanium dioxide and indigo carmine); or an orange shade (e.g., consisting of essentially of titanium dioxide and sunset yellow).
[0078] The above mentioned colorants that contain a coordinating metal are acceptable at a level approximately equal to or less than 0.025 parts of Compound B.
[0079] In suitable alternative embodiments, the aqueous film coating composition for use in the current invention comprises:
[0080] (i) a cellulosic film-forming polymer; and
[0081] (ii) a plasticizer.
[0082] Suitably, such compositions further comprise a colorant. Such compositions may optionally further comprise one or more additional adjuvants such as a detackifier, flow aid, surfactant, and secondary film-forming polymer.
[0083] Examples of optional detackifiers include lecithin, stearic acid, mineral oil, modified derivatized starch, tapioca dextrin, and polyethylene glycol. Examples of optional secondary film-forming polymers include sodium alginate, propylene glycol alginate, and polyvinylpyrrolidone. Examples of optional surfactants include dioctyl sodium sulfosuccinate and polysorbate 80. Examples of optional flow aids include talc, fumed silica, bentonite, hydrogenated vegetable oils, stearines, and waxes.
[0084] The aqueous film coat composition will typically comprise from about 5% to about 25%, suitably about 5% to about 20%, coating solids in the vehicle. In suitable embodiments, the solids typically comprise from about 25% to about 70%, suitably about 60% to about 70% film-forming polymer, about 5% to about 10%, suitably about 6% to about 8%, plasticizer, and about 20% to about 35% colorant, by weight.
[0085] A number of suitable aqueous film coating compositions are commercially available. The aqueous film coat composition may be provided in the form of a solution or dispersion. Alternatively, the composition may be provided in a dry form that can be combined with the vehicle components according to supplier instructions prior to coating the tablet. Suitably, aqueous film coating compositions are those commercially available from Colorcon, Inc. of West Point, Pa., under the trade name OPADRY and OPADRY II (nonlimiting examples include Opadry YS-1-7706-G white, Opadry Yellow 03B92357, Opadry Blue 03B90842). These compositions are available as dry film coating compositions that can be diluted in water shortly before use. OPADRY and OPADRY II formulations comprise a cellulosic film forming polymer (e.g., HPMC and/or HPC), and may contain polydextrose, maltodextrin, a plasticizer (e.g., triacetin, polyethylene glycol), polysorbate 80, a colorant (e.g., titanium dioxide, one or more dyes or lakes), and/or other suitable film-forming polymers (e.g., acrylate-methacrylate copolymers). Suitable OPADRY or OPADRY II formulations may comprise a plasticizer and one or more of maltodextrin, and polydextrose (including but not limited to a) triacetin and polydextrose or maltodextrin or lactose, or b) polyethylene glycol and polydextrose or maltodextrin).
[0086] The tablets are also suitably coated to provide a uniform coating without speckling. The tablets are typically coated to provide a dry tablet weight gain of from about 2 to about 5%, suitably about 3 to 4%.
[0087] The uncoated tablet cores are coated with the aqueous film coating composition by methods well known in the art using commercially available equipment (e.g., Thomas Accela-Cota, Vector Hi-Coater, Compu-Lab 36). In general, the process usually involves rolling or tumbling the tablets in a pan, or suspending the tablets on a cushion of air (fluidized bed), and intermittently or continuously (preferably continuously) spraying a fine mist of atomized droplets of the coating composition onto the tablets, the droplets wetting, spreading and coalescing on the surface of the tablets to form an adherent and coherent film coating. The tablets are typically heated to about 40 to 50° C., suitably about 45 to 50° C., e.g., by air having a temperature of up to about 75° C., suitably about 65 to 70° C.
Process of Making the Tablet
[0088] Pharmaceutical tablets of the invention that are wet-granulated can be prepared by a process comprising the steps of:
[0000] I) preparing the granules; which comprises the steps of:
a) mixing together the dry materials comprising eltrombopag olamine, a diluent, a binder, and optionally a disintegrant for a time sufficient to homogenize the materials; b) adding a granulating fluid to the mixture of dry materials, preferably while mixing; c) mixing the granulating fluid with the mixture of dry materials for a granulating time sufficient to generally uniformly wet the dry materials, so as to form wet granules; d) wet-milling the wet granules; e) drying the wet-milled granules to form dry granules; and f) dry milling the dry granules to form granules of desired size;
II) preparing the tablet; which comprises the steps of:
a) mixing the granules prepared in step I) f) with external excipients comprising a filler, a lubricant and a disintegrant for a time sufficient to homogenize the granules and external excipients; and b) compressing the mixture comprising the granules and external excipients to form a tablet.
[0097] Suitably, the tablets are further film-coated, especially aqueous film-coated.
[0098] In preparing wet-granulated granules, the dry materials may be mixed with suitable equipment such as known in the art (e.g., Niro-Fielder Blender/Granulator, Bear Varimixer, Key High Shear Mixer/Granulator) for a time sufficient to homogenize the materials, e.g., for about 3 minutes.
[0099] The granulating fluid is then added to the dry mixture, preferably while mixing. The granulating fluid is suitably water, although may alternatively be comprised of water in admixture with one or more of binders such as PVP and HPMC, from about 10 v/w % to about 30 v/w % of the granulating fluid, based on the total wet granulation mixture, is suitably used. The granulating fluid and dry materials may be mixed using suitable equipment such as known in the art (e.g., Niro-Fielder Blender/Granulator, Bear Varimixer, Key High Shear Mixer/Granulator) for a total time sufficient to generally uniformly wet the dry material so as to form wet granules, suitably for about 3 to about 15 minutes. Typically the fluid is added to the dry material with mixing over a period of about 1 to about 15 minutes, then the total batch is mixed for an additional time (post-granulating fluid-addition time), of about 0.5 minutes to about 6 minutes.
[0100] In a suitable embodiment, about 10 v/w % to about 30 v/w % granulating fluid and a post-granulating fluid-addition granulating time of about 6 minutes or less is used. Suitably, about 24 v/w % granulating fluid and a post-granulating fluid-addition granulating time of less than 3 minutes is used, e.g., about 2.5 minutes. Suitably, about 16 v/w % granulating fluid and a post-granulating fluid-addition granulating time of more than 2.5 minutes is used, e.g., about 4 minutes.
[0101] The wet granules are then wet-milled by methods such as are known in the art for providing a generally uniformly sized wet mass (such that the granules dry relatively evenly). Suitable wet-milling techniques may involve screening (e.g., manual screens), comminuting mills (such as a Co-mil, including but not limited to a 0.375″ screen), or extruders.
[0102] The wet-milled granules are dried by methods such as are known in the art for providing generally uniform drying, to a low residual amount of granulating fluid (preferably about 0.5% to about 1.0%). Fluid bed dryers are suitable drying equipment.
[0103] The dried granules are then dry-milled using known methods to provide generally uniformly sized granules (unimodal distribution), suitably having a mean particle diameter of less than 240 microns (found to provide improved content uniformity). Suitable dry-milling equipment includes Co-mils, including but not limited to having a 0.094″ screen.
[0104] Suitably the granules and the dry materials of the compression mix are generally unimodal in size distribution, in order to facilitate formation of a homogeneous mix and to mitigate possible segregation of the mix after blending. If necessary, the dry materials may be pre-screened to provide the desired particle size distribution. Screening of the lubricant may be particularly useful to deagglomerate the lubricant.
[0105] In preparing the compression mixture, the granules, filler, and disintegrant are mixed over a suitable period of time, about 5 to 15 minutes. Lubricant is then added and mixed for a suitable period of time, about 1 to 4 minutes. The mixture is then compressed into tablets using presses such as are known in the art (e.g., rotary tablet press).
[0106] It has been found that the above granulating fluid levels, granulating times, and excipients provide improved processing.
Capsules
[0107] The choice of particular types and amounts of excipients, and capsulation technique employed depends on the further properties of eltrombopag olamine and the excipients, e.g., compressibility, flowability, particle size, compatibility, and density. The capsules may be prepared according to methods known in the art, suitably filling a standard two piece hard gelatin capsule with eltrombopag olamine admixed with excipients, suitably filling a standard two piece hard gelatin capsule with granules prepared according to this invention, suitably on a scale suitable for commercial production. Suitable capsules of the invention comprise granules comprising eltrombopag olamine and one or more of fillers, binders and disintegrants, wherein the granules are mixed with additional filler, binder, disintegrant and/or lubricant to form a granular mixture that is filled into capsules.
[0108] Included in the present invention are pharmaceutical compositions in capsule form, suitably prepared on a commercial scale, that comprise eltrombopag olamine, wherein the capsule is made using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars.
[0109] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the capsule is made, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 90% of the eltrombopag olamine particles have a particle size greater than 10 micron but less than 90 micron.
[0110] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the capsule is made, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 90% of the eltrombopag olamine particles have a particle size greater than 10 micron but less than 90 micron, suitably greater than 20 micron but less than 50 micron.
[0111] Also included in the present invention are pharmaceutical compositions that comprise eltrombopag olamine, wherein the capsule is made, suitably on a commercial scale, using a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars, and about 50% of the eltrombopag olamine particles have a particle size greater than 5 micron but less than 50 micron, suitably greater than 5 micron but less than 20 micron.
[0112] The invented granules and solid oral pharmaceutical dosage forms may be administered in therapeutically effective amounts to treat or prevent a disease state, e.g., as described in the above referenced International Applications Nos. PCT/US01/16863, PCT/US03/16255 and PCT/US04/013468, the disclosures of which are herein incorporated by reference. It will be recognized by one of skill in the art that the optimal quantity and spacing of individual dosages of eltrombopag olamine formulations of the invention will be determined by the nature and extent of the condition being treated and the particular patient being treated, and that such optimums can be determined by conventional techniques. It will also be appreciated by one of skill in the art that the optimal course of treatment, i.e., the number of doses of eltrombopag olamine given per day for a defined number of days, can be ascertained by those skilled in the art using conventional course of treatment determination tests.
[0113] A method of this invention of inducing TPO agonist activity in humans comprises administering to a subject in need of such activity a therapeutically effective amount of a solid oral pharmaceutical dosage form of the present invention.
[0114] The invention also provides for the use of eltrombopag olamine in the manufacture of a solid oral pharmaceutical dosage form of the present invention.
[0115] The invention also provides for the use of eltrombopag olamine in the manufacture of a solid oral pharmaceutical dosage form of the present invention for use in enhancing platelet production.
[0116] The invention also provides for the use of eltrombopag olamine in the manufacture of a solid oral pharmaceutical dosage form of the present invention for use in treating thrombocytopenia.
[0117] The invention also provides for a solid oral pharmaceutical dosage form for use as a TPO mimetic which comprises eltrombopag olamine and a pharmaceutically acceptable carrier of the present invention.
[0118] The invention also provides for a solid oral pharmaceutical dosage form for use in the treatment of thrombocytopenia which comprises eltrombopag olamine and a pharmaceutically acceptable carrier of the present invention.
[0119] The invention also provides for a solid oral pharmaceutical dosage form for use in enhancing platelet production which comprises eltrombopag olamine and a pharmaceutically acceptable carrier of the present invention.
[0120] The invention also provides a process for preparing solid oral pharmaceutical dosage forms containing a diluent or diluents that are substantially free of coordinating metals and/or that are substantially free of reducing sugars and a therapeutically effective amount of eltrombopag olamine, which process comprises bringing eltrombopag olamine into association with the diluent or diluents.
[0121] No unacceptable toxicological effects are expected when the compound of the invention is administered in accordance with the present invention.
[0122] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following Examples, therefore, are to be construed as merely illustrative and not a limitation of the scope of the present invention.
[0123] All the excipients utilized herein are standard pharmaceutical grade excipients available from numerous manufacturers well known to those in the art.
EXAMPLES
Examples 1 to 7
Tablet Preparation
[0124] Wet granulated, tablets comprising eltrombopag olamine and the ingredients in Table 1 were prepared.
[0000]
TABLE 1
Tablet Strength
Component
12.5 mg
25 mg
25 mg
50 mg
50 mg
75 mg
100 mg
Granules 40% Drug-loaded
(39.9)
(79.7)
(79.7)
(159.4)
(159.4)
(239.1)
(318.8)
eltrombopag olamine, milled
15.95
31.9
31.9
63.8
63.8
95.7
127.6
Microcrystalline cellulose
7.45
14.9
14.9
29.8
29.8
44.7
59.6
Mannitol
14.9
29.7
29.7
59.5
59.5
89.2
118.9
Povidone
1.6
3.2
3.2
6.4
6.4
9.6
12.8
Purified water
—
—
—
—
Extra-granular components
Microcrystalline cellulose
119.4
238.8
238.8
159.1
159.1
79.3
NA
Sodium starch glycolate
14.0
28.0
28.0
28.0
28.0
28.0
27.6
Magnesium Stearate
1.75
3.5
3.5
3.5
3.5
3.5
3.5
Film-coating components
Purified water
—
—
—
—
Opadry ® white
8.9
14.0
14.0
14.0
Opadry Orange
14.0
Opadry Brown
14.0
Opadry Blue
14.0
Total tablet weight (mg/tablet)
183.9
364
364
364
364
364
364
[0125] Granules were prepared by separately weighing and screening mannitol, microcrystalline cellulose and povidone.
[0126] As a general procedure, the ingredients were blended with the active ingredient and then wet-granulated (in a high-shear wet-granulator) with purified water. The wet-granule mass was wet-milled, then dried in a fluid-bed dryer and the dried granules were milled.
[0127] Then extragranular ingredients (microcrystalline cellulose, if needed, and sodium starch glycolate) were separately weighed, screened and blended with the granules. Magnesium stearate was added and blended with the mixture. The blend was compressed and the tablet cores were then film coated. The tablets were film coated with an aqueous suspension of OPADRY film coating preparation.
Example 8
Tablet Preparation
[0128] Eltrombopag olamine tablets containing diluents with the coordinating metal calcium phosphate dibasic anhydrous were manufactured in a similar manner as described above. Tablet composition for the tablet coordinating metal diluent is provided in table 2.
[0000]
TABLE 2
Tablet Strength
Component
50 mg
Granules 40% Drug-loaded
(159.4)
eltrombopag olamine, milled
63.8
Calcium Phopshate dibasic anhydrous
89.3
Povidone
6.4
Purified water
—
Extra-granular components
Microcrystalline cellulose
159.1
Sodium starch glycolate
28.0
Magnesium Stearate
3.5
Film-coating components
Purified water
—
Opadry ® white
14.0
Total tablet weight (mg/tablet)
364
[0129] In FIG. 1 , the tablet prepared with no coordinating metal diluent (indicated as “with non-coordinating metal diluent”) is a eltrombopag 50 mg tablet generally prepared as described in Table 1 above and the tablet prepared with the coordinating metal diluent—Calcium Phopshate dibasic anhydrous—(indicated as “with co-ordinating metal diluent”) is a eltrombopag 50 mg tablet generally prepared as described in Table 2 above. Dissolution comparison was performed using USP Apparatus II, 50 rpm, in phosphate buffer pH 6.8 containing 0.5% Tween 80.
Example 9
[0130] FIG. 2 depicts the effect of API particle size distribution on eltrombopag olamine dissolution. Eltrombopag olamine 75 mg tablets were generally prepared in the manner described in Example 5, using different particle sizes. The particle size refers to the particle size of the drug granules used in the formulation.
[0131] Dissolution comparison was performed using USP Apparatus II, 50 rpm, in phosphate buffer pH 6.8 containing 0.5% Tween 80.
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Disclosed are novel pharmaceutical compositions containing 3′-[(2Z)-[1-(3,4-dimethylphenyl)-1,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylidene]hydrazino]-2′-hydroxy-[1,1′-biphenyl]-3-carboxylic acid bis-(monoethanolamine) (eltrombopag olamine) and processes for preparing the same.
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RELATED APPLICATIONS
[0001] This application claims priority from United States Provisional Patent Application Ser. No. 60/142,559, filed Jul. 7, 1999, entitled “Structure for Adjustably Attaching a Disc Brake Caliper to a Bicycle Frame.”
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention is directed toward bicycle brakes, and more particularly toward a structure for adjustably attaching a disc brake caliper to a bicycle frame.
[0004] 2. Background Art
[0005] Disc brakes for bicycles are growing in popularity as consumers demand and bicycle manufacturers strive to provide ever advancing technology on bicycles. Disc brake systems generally consist of a rotor which is fixedly attached to the hub of a bicycle wheel and a caliper which is fixedly attached to a wheel supporting portion of the bicycle frame and which receives the rotor between a pair of bike pads which are advanced into and out of contact with the rotor along a select axis. The wheel supporting portion of the frame has some structure for attaching the caliper to the chain or seat stay in the rear or fork in the front of the frame. This structure typically consists of a boss or a pair of bosses which extend from the frame substantially parallel to the plane of the rotor and which have internally threaded bores in their distal ends which are intended to lie in a plane normal to the plane of the rotor. The caliper, in turn, has a mounting foot which extends from the caliper body and includes a pair of holes corresponding to the bores in the ends of the attachment bosses. The caliper is then bolted to the frame by bolts axially received the holes in the mounting foot. When properly aligned, the rotor will be received between the brake pads of the caliper so that the brake pads of the caliper are advanced into and out of contact with the rotor along an axis that is normal to the plane of the rotor.
[0006] Assuming that the attachment bosses extend parallel to the plane of the rotor and that the ends of the attachment bosses lie in a plane perpendicular to the plane of the rotor, prior art calipers would be properly aligned with the brake pads being advanced along an axis normal to the rotor. In practice, however, the normal range of manufacturing tolerances in the bicycle and caliper makes it unlikely that the caliper will be properly aligned with respect to the rotor. When the caliper is not properly aligned, the brake pads will not strike the rotor flush which can degrade brake performance. It can even lead to the brake pads rubbing against the rotor and deteriorating bicycle performance.
[0007] One structure known in the prior art for addressing this improper alignment is providing elongate slots on the mounting foot of the caliper corresponding to the bores in the mounting bosses which extend substantially parallel to the select axis of advancement of the pads. These slots allow translational movement of the caliper toward and away from the rotor to precisely position the rotor intermediate the pads of the caliper. In addition, these slots enable the caliper to be canted about an axis parallel to an axis of the mounting boss bores to compensate for some misalignment between the rotor and the caliper. However, because these slots only allow for translational movement and some range of canting, they do not enable proper alignment with the rotor if the tolerances cause misalignment outside of these limited directions of travel.
[0008] The present invention is directed toward overcoming one or more of the problems discussed above.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is an attachment structure for a caliper of a disc brake assembly consisting of a caliper and a rotor. The caliper is attached to a wheel supporting portion of a cycle frame which supports a wheel with the rotor fixedly attached to the wheel and the rotor lying in a fixed a plane relative to the supporting portion of the frame. The supporting portion of the frame has a pair of attachment bores oriented to attach the caliper with the rotor received between a pair of brake pads advanced into and out of contact with the rotor by the caliper along a select axis. The attachment structure allows for infinite variation of the angle of incidence between the select axis and the plane of the rotor within a defined range. Attachment bolts secure the caliper to the frame with a select angle of incidence between the select axis and the plane of the rotor.
[0010] Another aspect of the present invention is a disc brake assembly attachable to a wheel supporting portion of a frame of a cycle. The disc brake assembly includes a rotor fixedly attached to a wheel mounted to the wheel supporting portion of the frame, with the rotor residing in a plane of fixed orientation relative to the wheel supporting portion of the frame. A caliper receives the rotor between a pair of brake pads with the caliper advancing the brake pads into and out of contact with the rotor along a select axis. An attachment structure attaches the caliper to the wheel supporting portion of the frame with the angle of incidence between the select axis and the plane of rotor being infinitely variable within a defined range. In this manner, the caliper can be aligned with the select axis normal to the rotor. At least one bolt is operatively associated with the attaching structure to secure the caliper to the frame with the select axis aligned normal to the rotor. The attaching structure preferably includes slots on the caliper substantially parallel to the select axis for enabling translational movement of the caliper toward and away from the rotor.
[0011] The attaching structure may include a pair of spaced bores on the wheel supporting portion of the frame defining a line substantially parallel to the plane of rotor, the bores having openings which lie in a plane substantially normal to the plane of the rotor. A convex surface is associated with the mouth of each bore. A mating concave surface is associated with a bottom of a mounting foot of the caliper. Aligned holes extend through each of the concave and convex surfaces and correspond to the bores in the wheel supporting portion of the frame. A pair of slots in the mounting foot of the caliper also corresponds to the bores. These slots are substantially parallel to the select axis. A bolt having a head and a shaft is axially received in each slot, aligned hole and corresponding bore with the head protruding therefrom. The bolt is threadably engaged with the bores to maintain the caliper with the select axis aligned normal to the rotor. The attaching structure preferably further includes a pair of washers having mating concave and convex surfaces and opposite flat surfaces receiving the bolt with one of the flat surfaces abutting a top of the mounting foot of the caliper and the other of the flat surfaces abutting the head of the bolt.
[0012] In one embodiment, the mating concave and convex surfaces associated with the mouth of each bore and the underside of the mounting foot of the caliper comprise a pair of washers having mating concave and convex surfaces and opposite flat surfaces, with the washer pairs residing with one of the flat surfaces abutting the bottom of the caliper mounting foot and the other of the flat surfaces abutting the wheel supporting portion of the frame.
[0013] In another embodiment, the mating concave and convex surfaces associated with the mouth of each bore and the bottom of the mounting foot consists of a pair of plates having the mating concave and convex surfaces and opposite flat surfaces, the pair of plates further including the aligned holes, the plates residing with one flat surface abutting the bottom of the mounting foot and the other flat surface abutting the wheel supporting portion of the frame. Preferably, the aligned holes are elongate and correspond to the slots in the caliper mounting foot.
[0014] Yet another aspect of the present invention is a structure for attaching a caliper of a disc brake system to a cycle frame with a pair of brake pads advanced by the caliper in operative engagement with a rotor of the disc brake system, the frame having a pair of threaded caliper mounting bores and the caliper having a mounting foot. The attachment structure consists of mating concave and convex surfaces between the frame and a bottom of the caliper mounting foot to pivot the caliper about a pivoting axis. A pair of holes corresponding to the caliper mounting bores extend through the concave and convex mounting surfaces. A pair of spaced slots on the caliper mounting foot extend transverse the pivoting axis and are aligned with the holes and the mounting bores. A pair of bolts are axially received in the aligned slots, holes and the threaded mounting bores with the bolts engaging the threaded mounting bores to maintain the pads of the caliper in a select orientation relative to the rotor. The mating concave and convex surfaces may be a pair of washers residing between the bottom of the caliper mounting foot and the frame corresponding to each of the caliper mounting bores. Alternatively, the mating concave and convex surfaces residing between the bottom of the caliper mounting foot and the frame maybe formed on a pair of elongate plates. Alternatively, one of the concave and convex surfaces may be on the bottom of the caliper mounting foot and the other may be on an elongate plate residing between the bottom of the caliper mounting foot and the frame. In this embodiment, the pair of holes in the elongate plate are preferably elongate to correspond to the slots in the caliper mounting foot. Preferably, mating concave and convex surfaces are further provided between the head of the bolt and the top of the caliper mounting foot. The mating concave and convex surfaces are preferably on a pair of washers corresponding to each of the bolt heads residing between the bolt heads and the top of the caliper mounting foot.
[0015] The structure for adjustably attaching a disc brake caliper to a bicycle frame of the present invention allows for infinite variation of the angle of incidence between and axis of movement of caliper brake pads and the plane of a rotor within a defined range. Thus, the caliper can be adjusted so that the select axis in is the desired orientation of normal to the plane of the rotor notwithstanding manufacturing tolerances and manufacturing defects that would cause the axis of pad travel of prior art calipers not to be normal to the plane of the rotor. In addition, the attachment structure allows translation of the caliper toward and away from the rotor to compensate for variations in the spacing between the attachment studs and the disc brake rotor amongst the bicycles of various manufacturers. The structure for adjustably attaching the disc brake is virtually self-adjusting within its defined range. The caliper can be readily self-aligned simply by loosening the attachment bolts, actuating the brake pads into abutment with the rotor and then tightening the attachment bolts. Thus, the many advantages of having the select axis of movement of the brake pads normal to the rotor can be achieved with minimal effort on the part of the user. Moreover, the structure providing these many advantages is inexpensive to manufacture and can be made from off the shelf parts making it an inexpensive solution to an otherwise vexing problem.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a perspective view of a caliper mounted to the front fork of a bicycle in operative association with a rotor using a structure for adjustably attaching a disc brake to a bicycle frame of the present invention;
[0017] [0017]FIG. 2 is an exploded view of the structure for adjustably attaching a disc brake caliper to a front fork of a bicycle frame of FIG. 1;
[0018] [0018]FIG. 3 is a perspective view of a caliper mounted to a chain stay of a bicycle frame in operative engagement with a rotor using a second embodiment of a structure for adjustably attaching a disc brake to a bicycle frame of the present invention;
[0019] [0019]FIG. 4 is an exploded view the structure for adjustably attaching a disc brake caliper to bicycle frame of FIG. 3;
[0020] [0020]FIG. 5 is a rear view of the caliper of FIG. 1 showing the translational movement of the caliper relative to the rotor afforded by the present invention;
[0021] [0021]FIG. 6 is a rear view of the caliper of FIG. 1 showing the canting movement afforded by the caliper relative to a rotor of the present invention;
[0022] [0022]FIG. 7 is a bottom view of the caliper of FIG. 1 showing the hinged movement of the caliper relative to the rotor afforded by the present invention; and
[0023] [0023]FIG. 8 is a perspective view of a third embodiment of an attachment structure of the present invention providing the translational movement of FIG. 5, the canting movement of FIG. 6, the hinged movement of FIG. 7 as well as axial movement along a rod.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] A disc brake system 10 consisting of a caliper 12 and a rotor 14 is illustrated in FIG. 1 with the caliper attached to a front fork 16 of a bicycle frame. Although omitted for the sake of clarity, the rotor 14 is fixedly attached to a hub of a wheel for rotation with the wheel with the wheel hub being attached to the bracket 18 of the front fork. Thus, the front fork 16 acts as a wheel support portion of the bicycle frame. The rotor 14 is maintained in a fixed plane relative the wheel and the front fork.
[0025] The rotor 14 is received between a pair of brake pads 20 , 22 attached to the caliper 12 which are best viewed in FIG. 7. The brake pads are advanced into and out of contact with the rotor along a select axis 24 which is intended to be normal to the plane 26 of the rotor 14 .
[0026] A pair of attachment bosses 30 extend from the fork 16 preferably parallel to the plane of the rotor 14 . Referring to FIG. 2, the distal ends 32 of the attachment bosses have an internally threaded bore 34 which is also preferably parallel to the plane of the rotor 14 . The distal ends of the attachment bosses 30 preferably each lie in a common plane which is normal to the plane of the rotor 14 . However, due to manufacturing tolerances and in some cases manufacturing defects, often one of the axis of the threaded bores 34 , the distal ends 32 of the attachment bosses 30 or the plane of the rotor 14 are not precisely in the desired alignment. A structure for adjustably attaching the caliper to a bicycle frame 28 is intended to allow for necessary realignment.
[0027] The structure for adjustably attaching the caliper to a bicycle frame 28 consists of first and second pairs of washers 36 , 38 . A first washer 40 of the washer pair 36 has a concave semispherical surface 42 and a flat surface 44 with a hole 45 extending there between. The second washer 46 of the washer pair 36 has a convex semispherical surface 48 which mates with the concave surface 42 . Opposite the convex surface 48 is a flat surface 50 . A hole 51 extends between the surfaces. The second washer pair 38 is identical to the first washer pair 36 . The first and second washer pairs 36 , 38 reside between the distal ends 32 of the attachment bosses 30 and the bottom 52 of a mounting foot 54 of the caliper 12 . Third and fourth identical washer pairs 56 , 58 reside between a top surface 60 of the mounting foot 54 and the head 62 of bolt 64 . The mounting foot 54 has a pair of elongate slots 66 which extend lengthwise parallel to the select axis 24 . The shaft 68 of the bolt 64 is axially received through the holes in the third washer pair and the elongate slot 66 and the holes in the first washer pair 36 and the shaft 68 is threadably engaged with the bore 34 of the attachment boss 30 . A conventional washer 70 may be further provided adjacent the head 62 of the attachment bolt 64 .
[0028] In use, with the caliper attached as described above, the caliper is moveable in several directions which enable the angle of incidence of the select axis 24 vary infinitely within a select range so that the select axis 24 can be aligned normal to the plane of the rotor 14 . Referring to FIG. 1, arrow 72 illustrates how the caliper can be moved by translation toward and away from the rotor 14 . This movement is also illustrated by the arrows 72 in FIG. 5. This movement is possible by virtue of the elongate slots 66 . The elongate slots 66 also enable canting of the caliper 12 relative to the rotor 14 as illustrated by arcuate arrow 74 in FIG. 1 and also in FIG. 6. Finally, the caliper can be pivoted about a virtual axis 76 such that the caliper is in essence hinged about the engaging concave and convex surfaces of the first and second washer pairs 36 , 38 . This movement is illustrated by the arrow 78 in FIGS. 1 and 7.
[0029] By virtue of the canting movement allowed by the elongate slots 66 and the hinged movement allowed by the engaging concave and convex surface of the first and second washer pairs 36 , 38 , the select axis 24 can be moved relative to the plane of the rotor 14 to have an angle of incidence which is infinitely variable in three dimensions within a select range of movement. Thus, the caliper 12 can be aligned so that the select axis 24 is normal to the plane of the rotor 14 . Furthermore, the elongate slot 66 enable translational movement of the caliper relative to the rotor 14 to the allow the rotor 14 to be placed in a desired position between the brake pads 22 .
[0030] [0030]FIG. 3. illustrates a second embodiment of the structure for adjustably attaching the caliper to a bicycle frame 28 A. In this embodiment, a mounting bracket 86 is fixedly attached to a chain stay 88 which would be at the rear of the bicycle frame. A bracket 90 is at the intersection of the chain stay 88 and the seat stay 92 to which a wheel, which has been omitted for clarity, can be attached to the rear of the bicycle frame. The caliper 14 A is fixedly attached to a hub of the wheel. As with caliper 14 of FIG. 1, caliper 14 A is maintained in a fixed plane relative to the wheel and the chain stay 88 . The mounting bracket 86 has a pair of internally threaded bores 93 the openings of which lie in a plane defined by the surface 94 which is intended to be substantially perpendicular to the plane of the caliper 14 A.
[0031] The second embodiment of the attachment structure for adjustably attaching a caliper to a bicycle frame 28 A consists of an elongate plate 94 having a pair of transverse elongate slots 96 extending between a concave surface 98 and a flat surface 100 . The caliper 12 A has a mounting foot 50 A having an elongate convex bottom surface 102 which mates with the concave surface 98 of the elongate plate 94 . A pair of elongate slots 104 corresponding with and aligning with the elongate slots 96 in the elongate plate 94 extend parallel to the select axis 24 between the top 106 and the convex bottom 102 of the foot 50 A. First and second washer pairs 108 , 110 which are identical to the washer pair 36 discussed above with regard to FIG. 2, reside between the head 62 A of the attachment bolt 64 A and the top 106 of the mounting foot 50 A. The shafts 68 A are axially received by an optional conventional washer 111 and the washer pairs 108 , 110 , the elongate slots 104 , in the mounting foot 50 , and the elongate slots 96 in the elongate plate 94 and threadably engaged in the threaded bores 93 to maintain the caliper in a select position.
[0032] As with the first embodiment discussed with referenced 1 , 2 , 5 , 6 and 7 , the elongate slots 96 , 104 allow translational movement in the direction of the arrow 72 and canting movement in the direction of the arcuate arrow 74 . The mating concave and convex surfaces allow for hinged movement as illustrated by arrow 78 . In this manner, the second embodiment 28 A allows for the same movement and adjustable attachment as the first embodiment 28 .
[0033] It should be noted that the first and second washer pairs 36 , 38 could be substituted for the plate 94 and the convex surface 102 of the foot 50 A. However, the second embodiment provides a greater surface area to resist slipping.
[0034] [0034]FIG. 8 illustrates a third embodiment in the present invention that allows for a fourth direction of movement of the caliper 12 . In this embodiment, a caliper attachment bracket 120 consists of a rod 122 attached to footing plates 124 at each end. The footing plates 124 include elongate slots 126 . The footing plates 124 are attachable to the distal ends of the attachment bosses 30 discussed with reference to FIGS. 1 and 2. A plate 128 having a transverse chanel 130 therein for receiving the bar 122 has a number of holes 132 to allow for fixed attachment of the plate 128 to the bottom of the caliper 12 with a number of screws or bolts, not shown. Once attached, the caliper can be moved translationally as indicated by the arrow 72 canted relative to a rotor illustrated by the arcuate arrows 74 in a hinged manner as illustrated by the arcuate arrow 78 and axially of the bar 122 as illustrated by the arrow 134 . Thus, the third embodiment illustrated in FIG. 8 allows for an additional direction of travel over the first and second embodiments 28 , 28 A.
[0035] The caliper attachment structure of the present invention allows for a great range of movement of the caliper so that the caliper pads can travel along a select axis normal to the plane of the operatively associated rotor regardless of manufacturing tolerances and minor defects. In this manner, braking efficiency can be maximized by assuring that the brake pads are brought into full-flush contact with the rotor. In addition, undesired rubbing between the caliper pads and rotor by misalignment can be minimized. The caliper attachment structure also provides for virtually instantaneous self-alignment. The user need only loosen the attachment bolts, actuate the caliper to advance the brake pads into engagement with the rotor and then tighten the attachment bolts. The attachment structure therefore compensates for manufacturing tolerances and manufacturing defects which can result in misalignment between caliper pads and a rotor of a disc brake system. As can be readily appreciated, these many advantages are provided by a structure which is capable of being fabricated from off the shelf parts and is easily assembled and, perhaps most importantly, is extremely easy for a user to employ.
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An attachment structure for a caliper of a disc brake assembly consisting of a caliper and a rotor. The caliper is attached to a wheel supporting portion of a cycle frame which supports a wheel with the rotor fixedly attached to the wheel and the rotor lying in a fixed a plane relative to the supporting portion of the frame. The supporting portion of the frame has a pair of attachment bores oriented to attach the caliper with the rotor received between a pair of brake pads advanced into and out of contact with the rotor by the caliper along a select axis. The attachment structure allows for infinite variation of the angle of incidence between the select axis and the plane of the rotor within a defined range. Attachment bolts secure the caliper to the frame with a select angle of incidence between the select axis and the plane of the rotor.
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FIELD OF THE INVENTION
The present invention relates to modems. More particularly it relates to switching systems for multiple function modems.
DESCRIPTION OF THE PRIOR ART
The early transmission of digital data between computers over the telephone network used a device-called a modem-that converts between a computer's digital signals and signals that can be carried on the telephone network's limited bandwidth analog transmission lines.
Early modems (the term modem stands for MOdulator DEModulator) were acoustically coupled to a telephone handset. Their sole function was to accomplish the conversion process. They did not dial or switch modes, where mode switching initially meant changing between voice and data. Rather, the user dialed the telephone number, and after a connection was made, put the receiver in an acoustical coupler which was the interface between the modem's electronics and the telephone handset. All modem communication over the telephone network went first through the telephone handset which contained considerable specialized circuitry including an isolation device known as a data access arrangement ("DAA"). To switch from data to voice, the user merely picked up the receiver out of the acoustical coupler.
Early modems were notoriously unreliable and slow due to the telephone system that was designed for voice rather than data. A poor connection which would nonetheless work for a voice communication was unworkable for data. As a result, extensive error correction and adaptive channel compensation features were added to modems. These features improved reliability; however, they slowed the communications process down. For example, each time modems on either end of a telephone wire make a data connection, they establish signal channel distortion compensation which involves sending test signals back and forth that are monitored for distortion and adjusting the receiving modem's electronics to compensate. This process requires considerable time. And each time there is a switch of mode, a new connection was made.
Later, modems were developed which switched modes in response to a control signal. This switching feature was electrically the same as was previously done by hand. Thus, the data connection was still broken. Later still, additional modes were added. In this context, the term mode refers to a set of features. That is, when a system is switched to a mode, the system will implement the features called for by the mode. In today's modern modems, it is desirable to be able to switch to several modes. Some modes are desired to maintain compatibility with old equipment. Yet other modes add new and desirable features. At least the following modes are desirable:
Telephone Mode which is sometimes referred to as plain old telephone systems ("POTS"): A user may wish to use the PC as a conventional telephone. That is, a PC is used to dial the telephone number, but when the other party picks up, the user merely wants to have a voice conversation over the telephone network. The user will just talk into the PC. Of Course the PC must have a microphone and speaker. The keyboard or a stored number is used to dial.
Cellular Mode: The cellular mode allows connection of a modem to a cellular telephone. A DAA is not required; however, a special interface which is different than a conventional telephone wire is required.
Business Audio: The business audio mode focuses on using a personal computer ("PC") an answering machine. This means that the PC must act as a tape recorder and play back messages. This requires the ability to get an audio signal in and out of the PC in a digitized format. That is, (1) an announcement must be recorded for later playback to incoming callers; (2) incoming messages must be recorded from either a POTS line or the cellular telephone system; and (3) messages that have been recorded must be played back.
Digital Simultaneous Voice and Data ("DSVD"): In this mode, once a data connection is made, the user can pick up the telephone hand set and talk to the other party without breaking the data connection. With DSVD, a combined digital voice and data signal comes into the modem, the modem microprocessor separates the voice and data, sends the data to the computer and sends the voice back out to be decoded and sent to a headset so that it can be heard. This requires an additional DSP. The second DSP decodes the audio while the first DSP is processing the modem data. A low speed analog SVD has also been commercialized, but uses the telephone as the voice I/O.
Finally, a modern modem must be able to support other industry standards. Of the other industry standards, "Voice View" a protocol developed and published by the Radish Company (commonly called and hereafter referred to as "Radish") is the most widely used. Thus the system must be able to emulate Radish switching such that if the system is talking to a second modem that only supports Radish, the system can also support Radish.
Because modems connect to conventional telephone wires, they must conform to the requirements of the telephone network. One such requirement is that all equipment connected to the network must be isolated by an interface device. The DAA performs this function. A conventional telephone line consists of two bi-directional wires. These wires come into one side of the DAA. On the other side of the DAA there are 4 wires: an outgoing wire, an incoming wire and a return wire for each. FIG. 1 is a block diagram of a DAA. Referring now to FIG. 1, wires 20 and 22 are bidirectional telephone wires. That is, they are in the telephone network. DAA 24 transforms telephone network wires 20 and 22 into a set of receive wires 26 and 28 and into a set of transmit wires 30 and 32. Lines 26-32 are unidirectional lines with one wire for signal and one for ground. This configuration is useful for echo cancellation. The telephone handset side of the DAA is known in the industry as the 4 wire point and is indicated by reference numeral 34. The telephone network side of the DAA is known in the industry as the two wire point and is indicated by reference numeral 36. A DAA is in every telephone base unit and every modem.
FIG. 2 is a block diagram of a prior art modem system with switching in response to a control signal as defined by the Radish standard. Referring to FIG. 2, reference numeral 38 refers to the system that includes a modem and switching. Telephone wires 20 and 22 are connected through a first set of switches 40 to a first DAA 42 located in modem 44. A second DAA 46 is connected directly to wires 20 and 22. Receiving wires 48 and 50 of DAA 46 are connected to a detector 52. Transmit wires 54 and 56 of DAA 46 are not used. DAA 46 provides isolation for access by detector 52 to telephone wires 20 and 22. Detector 52 looks for a signal sent by the sending modem that indicates that the next signal will be data. Detector 52 sends a signal over wire 58 to the micro controller 60 of modem 44. One side of a second set of switches 62 is connected directly to telephone wires 20 and 22. The other side of switch set 62 is connected to DAA 64 in telephone hand set 66. Switches 40 and 62 are controlled by signals generated by microcontroller 60 and supplied over control wire 68 such that when switches 62 are closed, switches 40 are open and visa versa. In this system, all mode switching is done on the two-wire side of the DAA. This system requires 3 DAA's: 42, 46, and 64.
Another factor affecting modem design is the advent of mobile computer communications. For mobile modem applications, a user cannot be expected to carry a conventional handset around. Yet, the conventional handset has much of the telephone interface circuitry built into it--particularly the DAA. In addition, the PCMCIA standard has become the accepted form factor for mobile computing add-in functions. Thus, any modem design intended for mobile computing must be able to fit into one of the PCMCIA, Type form factors.
SUMMARY OF THE INVENTION
The present invention consists of a switching multi-mode modem that includes a DAA having a two-wire side and a four-wire side. The two-wire side of the DAA is connected to a land based telephone network. The modem includes a first DSP capable of performing all modem digital signal processing functions and a second DSP capable of performing conversion and compression of analog voice signals to digital signals. The modem includes a headset connector and a cellular telephone connector and a switching network connected between the first DSP, the second DSP, the four-wire side of the DAA, the cellular telephone connector and the headset connector. The modem further contains a microcontroller which is connected to the first DSP and the second DSP and the switching network and separates audio signals from data signals and causes the switching network to switch into states that configure the modem to operate a plurality of separate modes.
The switching network may consist of four switches. The first of such switches has a base terminal connected to the input of the first digital signal processor and mutually exclusively connectable to three switchable terminals. The first switchable terminal is connected to the output of the cellular telephone. The second switchable terminal is connected to the output of the four wire side of the DAA. The third switchable terminal is connected to the output of the headset. The second of such switches has a base terminal connected to the input of the four wire side of the DAA and mutually exclusively connectable to two switchable terminals. The first switchable terminal is connected to the output of the first digital signal processor and the second switchable terminal is connected to the output of the headset. The third of such switches has a base terminal connected to the input of the headset and mutually exclusively connectable to three switchable terminals. The first switchable terminal is connected to the output of the first digital signal processor. The second switchable terminal is connected to the output of the second digital signal processor. The third switchable terminal is connected to the input of the vase terminal of the first switch. The fourth of such switches has a base terminal connected to the input of the cellular telephone and mutually exclusively connectable to two switchable terminals. The first switchable terminal is connected to the output of the headset and the second terminal of the second switch and the second switchable terminal is connected to the output of the first digital signal processor and to the first terminal of the second switch and to the first terminal of the third switch.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a basic DAA showing its basic functions.
FIG. 2 is a block diagram of a prior art modem system with switching between voice and data in response to a control signal when a modem is connected to a telephone line.
FIG. 3 is a block diagram of the basic system of the present invention connected to provide simultaneous voice and data features.
FIG. 4 is a block diagram of the system of the present invention when connected to provide business/audio mode features.
FIG. 5 is a block diagram of the system of the present invention when connected to provide Radish--voice mode features.
FIG. 6 is a block diagram of the system of the present invention when connected to provide Radish--data mode features.
FIG. 7 is a block diagram of the system of the present invention when connected to provide cellular transmission mode features.
FIG. 8 is a block diagram of the switch of the present invention.
FIG. 9 is a circuit schematic of switch A of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 is a block diagram of a system incorporating the features of the present invention. In FIG. 3, reference numeral 70 indicates the system generally. Telephone wires 20 and 22 lead into DAA 72 of system 70. Output wires 73 and 74 and input wires 75 and 76 connect the non-network side of DAA 72 with switch 77. Output wires 78 and 79 and input wires 80 and 81 connect switch 77 to DSP 82 which performs modem functions. The filtered and digitized signal is transmitted over data path 84 from DSP 82 to microcontroller 86 which may be a stand alone microcontroller or one built into the modem or it may be a host computer. Microcontroller 86 separates the audio from the data under firmware control and sends the audio portion over data path 88 to DSP 90 where it is converted back to analog. Microcontroller 86 is also connected to switch 77 over data path 89. DSP 90 is connected by output wires 91 and 92 and input wires 93 and 94 to switch 77. Output wires 95 and 96 and input wires 97 and 98 connect switch 77 with headset 100. Output wires 105 and 106 and input wires 107 and 108 connect switch 77 with cellular telephone 110. The signals between DSP 90 and headset 100 are bidirectional since full duplex voice is a requirement. A DAA is not needed in headset 100 because this is not a telephony application. That is, this part of the system is not connected to the telephone network. Data path 102 connects a host computer 104 with microcontroller 86 of modem 70.
The signals on wires 20 and 22 are analog voice and digital data encoded in analog modem format. The signals are bidirectional. Voice signals are generated by a microphone in headset 100 when the user speaks. Voice signals are also received and converted to sound by the speakers in headset 100. Thus analog audio signals are transmitted to and from headset 100. If originating in headset 100, the voice signals are digitized and compressed by DSP 90. They are then passed to microcontroller 86 where they are added to the data signal. This signal is then analog coded by DSP 82 and sent out through DAA 72 to the telephone network. When a voice signal comes in from the telephone system, microcontroller 86 strips off the analog portion and sends it to DSP 90 where it is converted to analog and passed to headset 100. DSP 90 performs voice digitizing and compression. DSP 82 performs modem functions. Both are controlled by microcontroller 86. The intelligence for the applications is in the application software of host 104. Modes may be selected by host 104 by sending commands to modem 70 by programming microprocessor 86 which in turn sets up DSPs 82 and 90 and switch 77 correctly.
FIG. 4 is a block diagram of the system of the present invention when set up to provide business/audio mode features. The business audio features allow a PC to be used as an answering machine. That is, (1) announcement must be recorded for later playback to incoming callers; (2) incoming messages must be recorded from either a POTS line or the cellular telephone system; and (3) messages that have been recorded must be played back. DSP 82 has the same functionality as DSPs 82 and 90 together. For business audio however, the voice and data functions are typically not performed simultaneously and thus two DSP's are not required. That is, DSP 90 is not used since there is a large installed base of software that supports this function using only DSP 82. This means that switch 77 must be able to switch voice into modem DSP 82. Referring now to FIG. 4, the speaker portion of headset 100 is connected via wires 95 and 96 to output wires 78 and 79 of DSP 82. The microphone portion of headset 100 is connected via wires 97 and 98 to input wires 80 and 81 of DSP 82. DSP 82 performs analog to digital and digital to analog conversion functions on the voice signals and passes along the signals via microcontroller 86 to host 104. The intelligence for handling the record and playback functions resides in the application software in host 104.
Radish emulation mode consist of two sub-modes: voice sub-mode and Radish data sub-mode. FIG. 5 is a block diagram of the configuration of switch 77 in the voice sub-mode and FIG. 6 is a block diagram of the configuration of switch 77 in the data sub-mode. In the voice sub-mode, both DSP 82 and DSP 90 add very little functionality. Indeed, the only function that they perform is that DSP 82 listens for the tone that is part of the Radish protocol that signals the modem to switch from voice to data. Referring now to FIG. 5, the speaker portion of headset 100 is connected vial wires 95 and 96 to wires 75 and 76 which are the output of DAA 72. Also, input wires 75 and 76 from DAA 72 are connected to input wires 80 and 81 of DSP 82. The microphone portion of headset 100 is connected via wires 97 and 98 to input wires 73 and 74 of DAA 72.
In the data sub-mode, as illustrated by FIG. 6, the data goes straight through and the voice is disconnected. This is equivalent to the modems that are in most common use today. Referring now to FIG. 6, the output of the four wire side of DAA 72 is connected via wires 75 and 76 to input wires 80 and 81 of DSP 82, and the output of DSP 82 is connected via output wires 78 and 79 and wires 73 and 74 to the input of the four wire side of DAA 72.
Cellular mode configures the modem to communicate over the cellular telephone network. This network is different than the ground based telephone network in certain respects one of which is that a DAA is not used. FIG. 7 is a block diagram illustrating the cellular telephone and POTS connections and the reason for requiring a separate cellular mode arrangement in switch 77. Referring now to FIG. 7, cellular telephone 110 takes the place of headset 100, and is connected to switch 77 by output wires 95 and 96 and by input wires 97 and 98. The signal to be sent out over cellular telephone or POTS is the same signal before reaching switch 77. However separate connections are required for the following reason. Suppose that a user has their cellular telephone connected to modem 70, but that the user uses a POTS line instead of the cellular telephone. If a parallel connector were used, then a cellular telephone that was turned off would be connected to the wires leading to the DAA causing the signal to the DAA to be corrupted. That is, there is a potential for not getting a signal out to the telephone wire since turning the cellular telephone off while it is connected to the modem is equivalent to grounding the cellular telephone line. Accordingly, the switch of the present invention is configured to provide isolation for the case where the user connects their cellular telephone to the modem, but simultaneously connects the modem to POTS. There will be sufficient connectors on future implementations of PCMCIA cards to create this problem. Referring now to FIG. 7, the output of cellular telephone 110 is connected via wires 97 and 98 and switch 77 to wires 80 and 81 of DSP 82, and the output of DSP 82 is supplied via wires 78 and 79, switch 77 and wires 95 and 96 to the input to cellular telephone 110.
FIG. 8 is a schematic representation of the switching that must be accomplished to implement the described modes. The schematic of FIG. 8 is shown as a single ended (signal and return) as opposed to a differential (plus signal, minus signal and return) schematic for simplicity and ease of understanding. Thus all data paths appearing in FIG. 8 as a single line are in reality a unidirectional signal wire and a ground wire.
Referring now to FIG. 8, switch A has a base terminal 194 and terminals labeled 1, 2 and 3 and hereafter referenced as A1, A2 and A3. Base terminal 194 can be connected under computer control to any one of terminals A1, A2 or A3; however connections are mutually exclusive. Base terminal 194 is connected by data path 196 to the analog input terminal 198 of DSP 82. It is also connected via data path 234 to terminal C3. Data path 196 carries analog signals coming into DSP 82 of modem 70. Terminal A1 is connected via data path 200 to cellular telephone 202. Data path 200 carries incoming analog signals from the cellular network through cellular telephone 202 to modem 70. Terminal A2 is connected via data path 204 to the analog output of the four wire side of DAA 72. Data path 204 carries incoming analog signals from DAA 72 to modem 70. Terminal A3 is connected by data path 206 and 207 to analog input 208 of DSP 90 and microphone 210 of headset 100. Data paths 206 and 207 carry incoming voice analog data from microphone 210 in headset 100.
Switch B has a base terminal 212 and terminals labeled 1, 2 and 3 and hereafter referenced as B1, B2 and B3. Base terminal 212 can be connected under computer control to any one of terminals B1, B2 or B3; however connections are mutually exclusive. Base terminal 212 is connected by data path 214 to the analog input terminal of the four-wire side of DAA 72. Data path 214 carries outgoing analog signals to DAA 72. Terminal B1 is connected via data path 216 and data path 219 to analog output 217 of DSP 82. Terminal B1 is also connected by data path 218 to terminals C1 and D3. Data path 216 and data path 219 carries outgoing analog signals from DSP 82 through switch B to DAA 72. Terminal B2 is unconnected and therefore null. This position corresponds to "off" which means that if B2 is selected, no signal appears on base terminal 212. Terminal B3 is connected by data path 220 to the common point between analog input 208 of DSP 90 and microphone 210 of headset 100. Terminal B3 is also connected by data path 222 to terminal D1. Data paths 220 and 222 carry incoming voice analog data from microphone 210 in headset 100. Base terminal 212 can be connected to either terminal B1, B2 or B3; however connections are mutually exclusive.
Switch C has a base terminal 224 and terminals labeled 1, 2 and 3 and hereafter referenced as C1, C2 and C3. Base terminal 224 can be connected under computer control to any one of terminals C1, C2 or C3; however connections are mutually exclusive. Base terminal 224 is connected by data path 226 to head phone 228 of headset 100. Terminal C1 is connected via data path 218 to the analog output 217 of DSP 82. Terminal C1 is also connected by data path 218 to terminal D3 and by data paths 218 and 216 to terminal B1. Terminal C2 is connected by data path 230 to analog output 232 of DSP 90. Terminal C3 is connected by data path 234 to the common point between analog input 198 of DSP 82 and base terminal 194 of switch A. Data path 234 carries the analog output signal from DAA 72 (through switch A) or cellular telephone 202 to headset 228.
Switch D has a base terminal 236 and terminals labeled 1, 2 and 3 and hereafter referenced as D1, D2 and D3. Base terminal 236 can be connected under computer control to any one of terminals D1, D2 or D3; however connections are mutually exclusive. Base terminal 236 is connected by data path 238 to the analog input terminal 240 of cellular telephone 110. Data path 200 carries output analog signals from cellular telephone 110 to switch A. Terminal D1 is connected via data paths 222 and 207 to the common point between analog input 208 of DSP 90 and microphone 210. Terminal D1 is also connected by data path 220 and data path 222 to terminal B3. Terminal D2 is unconnected and therefore null. This position corresponds to "off" which means that if D2 is selected, no signal appears on base terminal 236. Terminal D3 is connected by data path 218 and 219 to analog output 217 of DSP 82. Terminal D3 is also connected by data path 216 to terminal B1 and by data path 218 to terminal C1.
In operation, the switch of FIG. 8 works as follows. Switch A connects input 198 of DSP 82 to three sources of signals: cellular telephone 110, DAA 72 and microphone 210 of headset 100. Note that headset is not a standard phone because a standard phone contains a DAA. Switch A also connects terminal C3 with the same three signal sources. When switch A is in position A1, the output of cellular telephone 110 is connected to the input of DSP 82. This position is selected when using a cellular telephone. When switch A is in position A2, the output of DAA 72 is connected to the input of DSP 82. This position is selected for POTS modes. When switch A is in position A3, the output of headset 100 is connected to input 217 of DSP 82. This position is used for business/audio announcement recording. Thus, switch A controls the line input into the modem DSP and switches between cellular, business audio or telephone.
Switch B takes signals from two sources: the output of DSP 82 and the output of headset 100. Switch B controls the input to the four-wire input of DAA 72. When switch B is in position B1, the output of DSP 82 is connected to the input of DAA 72. This position is selected for Radish data mode emulation and business/audio mode. When switch B is in position B2, nothing is connected to the four-wire input of DAA 72. This position is selected for cellular mode. When switch B is in position B3, the output of headset 100 is connected to the four-wire input of DAA 72. This position is used for Radish voice mode. Thus, switch B controls the line input into the DAA and switches between the microphone 210 and DSP 82 output.
Switch C takes signals from three sources: the output of DSP 90, the output of DAA 72 (through switch A) and the output of DSP 82. When switch C is in position C1, the output of DSP 82 is connected to headphone 228. This position is selected for business/audio. When switch C is in position C2, the output of DSP 90 is connected to headphone 228. This position is selected for Radish data emulation and DSVD mode. When switch C is in position C3, the output of DAA 72 is connected through switch A to headphone 228. This position is used for Radish voice emulation. Thus, switch C controls the input to headphone 228. It switches between DSVDmode and Radish data mode, and business/audio and Radish voice mode
Switch D takes signals from two sources: the output of DSP 82 and microphone 210 of headset 100. When switch D is in position D1, the output of headset 100 is connected to the input of cellular telephone 110. This position is selected for cellular Radish voice emulation mode. When switch D is in position D2, nothing is connected to the input of cellular telephone 110. This position is selected for POTS mode. When switch D is in position D3, the output of DSP 28 is connected to cellular telephone 110. This position is used for cellular Radish data mode emulation and business/audio mode. Thus, switch D controls the input to cellular telephone 110 and switches between headset 100 and the output of DSP 82.
Five control signals are needed to control the four switches of FIG. 8. These signals are generated by microcontroller 86. The connections are not shown in FIG. 8. The five control signals are
Bus/Audio:
An active high signal indicating that business audio mode is active.
Radish Voice:
an active high signal indicating that the headset is connected.
Radish Data:
an active high signal indicating that the downline telephone is connected.
Cellular:
an active high signal indicating that the downline telephone is a cellular telephone.
POTS:
an active high signal indicating that the downline telephone is a Plain Old Telephone System
The condition of the control signals required to implement the desired modes are set out in Table 1. Referring now to Table 1, the modes are the headings for the columns and the switches are the headings for the rows. A "1" in a box indicates that the switch on that line is selected to that column. A "0" indicates that the switch is not selected. For example, if the cellular, RAD V (Radish Voice) is the desired mode, switches A1 and B2 and C3 and D3 are selected. This is indicated in Table 1 by the "1" in the RAD V column next to the selected switches. In like manner, if business/audio is the desired mode, switches A3 and B2 and C1 and D2 are selected. Rad V means Radish voice. Rad D means Radish data.
TABLE 1______________________________________ MODES CELLULAR POTS TERM- RAD RAD RAD RADSWITCH INAL V D V D B/A______________________________________A A1 1 1 0 0 0 A2 0 0 1 1 0 A3 0 0 0 0 1B B1 0 0 0 1 0 B2 1 1 0 0 1 B3 0 0 1 0 0C C1 0 0 0 0 1 C2 0 1 0 1 0 C3 1 0 1 0 0D D1 1 0 0 0 0 D2 0 0 1 1 1 D3 0 1 0 0 0______________________________________
FIG. 9 is a schematic of an actual implementation of switch A of FIG. 8. Referring now to FIG. 9, switch A is built around operational amplifier 300 which has an output 302 and input 304 and gain control resistors 306 and 308. Input 304 of operational amplifier 300 is connected to three input field effect transistors ("FET") 310, 318 and 326. FET 310 has input resistors 312 and 314 connected to its source and gate 316. The drain of FET 310 is connected ground 334. FET 318 has input resistors 320 and 322 connected to its source and its drain is connected to ground 334. Terminal 324 is the gate. FET 326 has input resistors 328 and 330 connected to its source and ground 334 connected to its drain. Terminal 332 is the gate.
FET 310 corresponds to switch A1; FET 318 corresponds to switch A2 and FET 326 corresponds to switch A3 in FIG. 9.
FET's 310, 318 and 326 conduct when the signal on their respective gates is high. Thus when the signal on the gate is high, the mid-point between the two input transistors is shorted to ground 334. Thus, to select a particular input, the FET connected to the input to be selected is turned off and the other two FETs turned on. In this way only the input signal to the FET that is turned off reaches input 304 of operational amplifier 300. Resistors 306 and 308 determine the gain of the switch and are typically set to produce a total gain of 1.
The signals on gates 316, 324 and 332 needed to achieve the proper switching are set out in Table 1.
Switches B, C and D may be implemented in a similar fashion as to switch A shown in FIG. 9.
It will be appreciated from the foregoing that the preferred embodiment is subject to numerous adaptions and modifications without departing from the scope of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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A switching multi-mode modem that switches on the four wire side of the DAA where the two-wire side of the DAA is connected to a land based telephone network. The modem includes a DAA, a first DSP capable of performing all modem digital signal processing functions and a second DSP capable of performing conversion and compression of analog voice signals to digital signals. The modem includes a headset connector and a cellular telephone connector and a switching network connected between the first DSP, the second DSP, the four-wire side of the DAA, the cellular telephone connector and the headset connector. The modem further contains a microcontroller which is connected to the first DSP and the second DSP and the switching network and separates audio signals from data signals and causes the switching network to switch into states that configure the modem to operate in one of the following states: Radish voice mode, or a Radish data mode, or a cellular telephone mode, or a business/audio mode or a digital simultaneous voice and data mode upon command from said microcontroller.
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The Government has rights in this invention pursuant to Contract Number AF19(628)-80-C-0002 awarded by the U.S. Department of the Air Force and Contract Number DE-AC02-80ER10179 awarded by the U.S. Department of Energy.
This application is a continuation of application Ser. No. 332,553 filed Dec. 21, 1981 now abandoned which is a continuation of Ser. No. 181,102 filed Aug. 25, 1980 now abandoned.
BACKGROUND OF THE INVENTION
This invention is an improvement on an earlier invention disclosed in copending application Ser. No. 756,358 of Henry I. Smith for Enhancing Epitaxy and Preferred Orientation, now U.S. Pat. No. 4,333,792, granted June 8, 1982, and relates, in general, to improving the crystallographic quality of solid films grown on surfaces of solid substrates, and more particularly, to improved means for obtaining epitaxial or preferred orientation films on solid substrates, both crystalline and amorphous.
Much of modern technology makes use of thin solid films on the surfaces of solid substrates. Epitaxial and preferred orientation films are particularly important, notably in microelectronic devices, thin film optical devices and solar cells. Thus, improved methods of preparing epitaxial and preferred orientation films are of great importance.
The principle involved in the earlier invention, referenced above, was to use a plurality of artificial defects, formed at predetermined locations at the surface of a solid substrate, to determine, control or influence, by means of the geometric arrangement of adjacent defects, the crystallographic orientation of a film deposited at said surface. The said artificial defects were either (1) artificial point defects or (2) artificial surface relief structure. The method disclosed in said earlier patent has been named "graphoepitaxy" (see "Crystallographic Orientation of Silicon on an Amorphous Substrate Using an Artificial Surface Relief Grating and Laser Crystallization", by M. W. Geis, D. C. Flanders and H. I. Smith, in Applied Physics Letters, Vol. 35, pp. 71-74, July 1, 1979). The name is derived from the Greek ("grapho" meaning to write or incise) and was chosen to convey the principle of using an artificially created surface pattern to induce epitaxy. In addition to the aforesaid copending application Ser. No. 756,358) two additional copending applications disclose improvements on the graphoepitaxy process. These copending applications are entitled "Improving Graphoepitaxy", by M. W. Geis, D. C. Flanders and H. I. Smith, Ser. No. 43,541 filed May 29, 1979, now abandoned, and "Three Dimensional Integration by Graphoepitaxy", by H. I. Smith, D. C. Flanders and M. W. Geis, Ser. No. 43,389 filed May 29, 1979, now abandoned. The present invention concerns (1) the use of a cover or "cap" of material over a film to be oriented; (2) the use of such a cap over a film to be oriented wherein the film is formed into discrete islands or stripes; (3) the use of such a cap over a film to be oriented wherein the substrate on which the film is located has artificial surface relief structure formed in it; (4) the use of such a cap over a film to be oriented wherein the cap has artificial surface relief structure formed in it; (5) the use of such a cap over a film to be oriented wherein both the substrate and the cap have artificial surface relief structure formed in them; (6) the use of a cap over a film to be oriented in any of the above configurations together with heating of the film by irradiation with electromagnetic radiation.
SUMMARY OF THE INVENTION
A film, consisting of a continuous sheet of material on a substrate or formed into one or more discrete islands or stripes on a substrate, is covered with a "cap" that consists of a second film or covering of material. Thereafter, the first film is induced to take on a preferred or epitaxial crystallographic orientation by heating it to a high temperature.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1: Illustrates a strip-heater oven in which a sample is located on top of the lower strip. Current passed through the two strips heats the sample to a high temperature such that crystallization occurs in a silicon film. The sample configuration is depicted in the inset which shows an SiO 2 substrate in which a relief structure is formed, a silicon film, and a cap of SiO 2 covering said film.
FIG. 2(a): Illustrates a sample configuration consisting of a substrate, a film and a cap.
FIG. 2(b): Illustrates a sample configuration in which a relief structure is formed in a substrate, a film is formed on top of it and a cap is formed on top of said film.
FIG. 2(c): Depicts a configuration in which a film is formed into discrete islands on a substrate and then covered with a cap.
FIG. 2(d): Depicts a configuration in which a relief structure is formed on top of a film and a cap is located on top of said film.
FIG. 2(e): Depicts a configuration in which a relief structure is formed on a substrate, a film is formed thereon and a cap having no relief structure in it is formed on top of said film.
FIG. 2(f): Depicts a configuration in which relief structures are formed both in the substrate and in the cap covering a film.
FIG. 2(g): Depicts a configuration in which a grating is formed in a substrate and in a cap over a film, and the two gratings are not parallel.
FIG. 2(h): Depicts a configuration in which a relief structure is formed on a substrate and a film is formed into islands on top of said relief structure and said islands are covered with a cap.
FIG. 2(i): Depicts a configuration in which a film on a substrate is formed into discrete islands, a relief structure is formed in said islands and the islands are covered with a cap.
FIG. 2(j): Depicts a configuration in which a film is formed into discrete islands and a cap is formed on only the top side of said islands.
FIG. 2(k): Depicts a configuration in which a relief structure is formed on a substrate, a discrete island is formed thereon and a cap covers only the top side of said island.
FIG. 2(l): Depicts a configuration in which an island is formed on a substrate and a relief structure is formed on said island and the top of said island is covered with a cap.
DETAILED DESCRIPTION
The copending application entitled, "Improving Graphoepitaxy", described a process that had been used to orient silicon films. That process included the formation of a relief grating in a SiO 2 substrate, the deposition of amorphous or fine grain polycrystalline silicon over the substrate and the crystallization of the silicon under a laser beam. If the crystallization was done in air at an appropriate power level, the silicon became oriented relative to the relief grating. Subsequent experimental work and x-ray analysis (see M. W. Geis, D. A. Antoniadis, D. J. Silversmith, R. W. Mountain and H. I. Smith, "Silicon graphoepitaxy using a strip-heater oven", published in Applied Physics Letters, September 1980), showed that the silicon films over the gratings consisted of many crystallites having their <100> directions parallel to the grating axis to within about 8 to 15 degrees and perpendicular to the substrate plane to within about 3 degrees. Research also showed that an oxide film formed over the silicon when it was heated with the laser in air to near the crystallization temperature, and that this oxide film was necessary to achieve a (100) texture or a strong alignment effect. For example, laser crystallization in inert gases such as argon yielded neither (100) texture nor orientation.
The most recent improvement of the silicon graphoepitaxy process includes depositing amorphous or polycrystalline silicon over a relief grating in an SiO 2 substrate, intentionally depositing an SiO 2 overlayer or "cap" on top of the silicon prior to crystallization, and using a strip-heater oven, rather than a laser, to heat the sample and produce crystallization. FIG. 1 depicts a strip-heater oven as well as the cross-section of such a sample configuration corresponding to FIG. 2(b). As reported in the journal article in the September 1980 issue of Applied Physics Letters, crystallization with the strip-heater oven of silicon films in the same configuration depicted in FIG. 2(a) (i.e., a continuous film, 2, on a substrate, 1, with no surface relief structure and with a cap, 3, over the film) wherein the substrate and cap were SiO 2 , yielded a strong (100) texture (i.e., <100> directions of grains are substantially perpendicular to the substrate surface). The sample configuration depicted in FIG. 2(b) (i.e., a continuous film, 5, over a surface relief structure, 7, in a substrate, 4, with a cap, 6, over the film), wherein the film was Si and the substrate and cap were SiO 2 , yielded a highly oriented film after strip-oven heating to the crystallization temperature. With the sample configuration depicted in FIG. 2(c), (i.e., discrete islands of a film, 9, over a substrate, 8, and a cap, 10, with no surface relief structure in either cap or substrate) for the case of Si islands in the form of stripes rectangular islands with the length many times greater than the width on SiO 2 substrates with SiO 2 caps, a (111) texture was obtained after strip-oven heating to the crystallization temperature. (This result was not reported in the above journal article.)
FIG. 2 depicts a variety of sample configurations encompassed within the inventive concepts of this application. All of said configurations include a substrate, a film to be oriented and a cap. A relief structure may be present in the substrate or the cap or both.
FIG. 2(c) depicts a sample configuration in which a film, 9, is formed into discrete islands over a substrate, 8, and thereafter said film islands are covered with a cap, 10, which covers the top and some of the sidewall area of the island. Said islands can be in a variety of shapes including squares, rectangles, and parallelograms.
FIG. 2(d) depicts a configuration in which the film, 12, is located on top of the substrate, 11, and the relief structure, 14, is formed in the film, 12, the cap, 13, is formed over said relief structure.
FIG. 2(e) depicts a configuration in which a relief structure, 18, is formed only in substrate, 15, the film to be oriented is located on top of said substrate and the cap, 17, is formed on top of said film.
FIG. 2(f) depicts a configuration in which a relief structure, 22, is formed in both the substrate, 19, and the cap, 21, the film, 20, being located between said cap and said substrate.
FIG. 2(g) depicts a configuration in which relief structures are present in both the substrate, 23, and the cap, 25, and said relief structures are gratings, and the axes of said gratings are oriented in different directions.
In FIG. 2(g) the grating in the cap is oriented orthogonally to the grating in the substrate, but other angles may also be employed.
FIG. 2(h) depicts a configuration in which the film, 28, is formed into discrete islands over a substrate, 27, in which a relief structure, 30, is formed and the discrete islands are covered with a cap, 29.
FIG. 2(i) depicts a configuration in which discrete islands, 32, are formed on substrate, 31, and a relief structure, 34, is formed on the top side of said islands, and said islands are covered with a cap, 33, which encloses the top side and at least some of the sidewall area of the islands. FIG. 2(j) depicts a configuration in which a cap, 37, is formed on only the top side of a discrete island, 36, located on top of substrate, 35.
FIG. 2(k) depicts a configuration in which discrete islands, 39, are located on top of substrate, 38, in which a relief structure, 41, is formed and said island is covered only on the top side with a cap, 40.
FIG. 2(l) depicts a configuration in which discrete islands, 43, are located on top of substrate, 42, and a relief structure, 45, is formed in the top side of said island which is covered with cap, 44, on the top side only.
There has been described novel structure and techniques for enhancing epitaxy and preferred orientation. It is evident that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in or possessed by the apparatus and techniques herein disclosed and limited solely by the spirit and scope of the appended claims.
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Improvements on the graphoepitaxial process for obtaining epitaxial or preferred orientation films are described wherein a cap of material is formed over the film to be oriented, artificial surface-relief structure may be present in the substrate, the cap, or both, and the film may be heated by irradiation with electromagnetic radiation.
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TECHNICAL FIELD
The invention relates to a linear drive for a belt pretensioner.
BACKGROUND OF THE INVENTION
A linear drive for a belt pretensioner is disclosed in DE-A 44 15 109. The linear drive disclosed in DE-A 44 15 109 comprises a cylinder tube and a piston arranged for sliding movement in the cylinder tube. The piston has a hollow interior space and an end wall at one axial end. The piston includes a pyrotechnic drive charge which, after being fired, causes the interior space of the piston to be subjected to gas under pressure. The pyrotechnic drive charge is fired in the event of a vehicle collision so that, under the action of the gas produced by the drive charge, the piston performs a tensioning stroke which is converted by the belt pretensioner into rotation of a belt drum of a belt retractor in a belt take-up direction. As a result, belt slack is removed from the belt system so that the vehicle occupant participates in vehicle deceleration from the earliest possible point in time in an accident.
One problem with the aforementioned linear drive is inadvertent firing of the pyrotechnic drive charge under unfavorable conditions, such as during over-heating of the vehicle following a fire in the vehicle, or when the vehicle occupant has already been displaced forward. DE-A 44 15 109 discloses designing the cylinder tube to be burst-proof and thus effective to prevent any danger resulting from the inadvertent firing of the drive charge under unfavorable conditions. Such a design results, however, in an increase in weight.
SUMMARY OF THE INVENTION
The present invention provides a linear drive which has a reduced weight and which is safe from bursting of the cylinder tube.
According to the invention, a linear drive for a belt pretensioner comprises a cylinder tube with a hollow inner space, a pyrotechnic drive charge which generates a pressurized gas, and a piston able to be displaced in the inner space of the cylinder tube under the action of the pressurized gas. The piston has a hollow interior space and an axial end having an end wall. The end wall has a passage opening which is closed by a blow-out patch. The blow-out patch clears the passage opening when there is excessive pressure in the interior space of the piston so that such pressure may be released from the interior space of the piston to forestall bursting of the cylinder tube without having to be particularly massive in design. By appropriate selection of the dimensions of the blow-out patch, the maximum pressure obtained in the interior space of the piston may be set and adapted to the respective conditions.
In accordance with a preferred development of the invention, the blow-out patch has a calibrated discharge flow opening which faces the passage opening. This design offers, in addition to a limitation of the maximum pressure occurring in the interior space of the piston, certain advantages regarding the behavior of the linear drive after belt pretensioning has taken place, particularly when the belt drum is connected with an energy receiving device such as a torsion rod adapted to take up load peaks in the belt system. Such an energy take-up device is described in DE-A 42 27 781. After the completion of belt pretensioning, the belt drum revolves in the pay-out direction against the action of the energy take-up device. Due to the coupling of the belt drum with the linear drive, the piston of the linear drive reverses its movement toward its initial position. Having the discharge opening in the interior space of the piston ensures that, upon the aforementioned reverse movement of the piston, no gas pressure opposes such reverse motion. The discharge opening is also responsible for pressure losses during the tensioning stroke of the piston. However, since the reverse motion of the piston takes place very slowly as compared with the tensioning stroke, a comparatively small discharge opening will be sufficient for venting of the interior space of the piston during the reverse motion of the piston so that pressure losses during rapid tensioning movement of the piston are low. Furthermore, such low pressure losses may be compensated for by having a higher output pyrotechnic drive charge.
Another preferred feature of the invention is that the blow-out patch is press-fitted in the interior space to ensure a particularly firm positioning of the blow-out patch in the interior space of the piston.
As an alternative to the press-fitted blow-out patch design, the patch may have a tubular attachment skirt which extends through the passage opening and secures the blow-out patch to the end wall by a crimped-over edge. In this manner, a particularly reliable attachment of the blow-out patch to the end wall is obtained.
In accordance with a further preferred embodiment of the invention, the blow-out patch has a connection part extending through the passage opening and connected with a tear-off part engaging the interior wall surface of the cylinder tube. The tear-off part is able to be shifted in the cylinder tube in a direction in accordance with the direction of motion of the piston on firing of the drive charge while becoming locked in the cylinder tube upon movement of the piston in the opposite direction. Further, upon continued movement of the piston, the connection part tears from the blow-out patch to clear the passage opening. According to this design, it is possible to attain the same advantageous effects as described for the other embodiments, but without pressure losses during the tensioning stroke.
Preferably, the blow-out patch is made of a metallic foil. This leads to high reproducibility of the pressure values at which the passage opening is cleared since metallic foil can be produced with tight tolerances and its burst pressure is relatively unaffected by changes in temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the invention will become more apparent to one skilled in the art upon consideration of the following description of the invention and the accompanying drawings in which:
FIG. 1 is an exploded perspective view of a linear drive in accordance with the invention with a belt pretensioner and a belt retractor;
FIG. 2 diagrammatically shows a section taken through a linear drive in accordance with the invention as a first embodiment in the initial position;
FIG. 3 diagrammatically shows a section taken through the linear drive of FIG. 2 after the tensioning stroke has been completed;
FIG. 4 shows part of the linear drive of FIG. 2 on a larger scale;
FIG. 5 is an elevational view corresponding to FIG. 4 showing a second embodiment of the invention;
FIG. 6 is a view corresponding to FIG. 4 showing a third embodiment of the invention;
FIG. 7 is a view corresponding to FIG. 4 showing a fourth embodiment of the invention in the initial position; and
FIG. 8 is a diagrammatic section taken through the linear drive of the fourth embodiment of the invention after performance of the tensioning stroke and after completion of reverse motion of the piston into the initial position thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a linear drive 10 constructed in accordance with the invention together with an associated belt pretensioner 12 and a belt retractor 14. The belt pretensioner 12 is arranged to act on the belt retractor 12 via gearing 16.
As shown in FIG. 2, the linear drive 10 comprises a cylinder tube 20 and a piston 22 adapted to move inside the cylinder tube. The piston 22 has a hollow interior space 24 having an end wall 26 at one end and a pyrotechnic drive charge 28 at the opposite axial end. A seal ring 30 is arranged between the cylinder tube 20 and the piston 22. On the lowermost (as viewed in FIG. 2) end of the cylinder tube 22, the cylinder tube is shut off by a plug 32. The plug 32 contains the electrical ignition contacts for firing the drive charge 28. At the opposite end of the cylinder tube 20, the cylinder tube has a piston catcher 33 with an opening 34. The opening 34 vents the cylinder tube 20 during a tensioning stroke of the piston 22.
On an outer axially extending surface, the piston 22 has gearing teeth 36 extending in parallel with its longitudinal axis and cooperating with a gear wheel of the gearing 16 in order to convert a tensioning stroke of the piston 22 into rotary motion. The rotary motion is transmitted to the belt drum of the belt retractor 14 as rotation in the belt take-up direction. The tensioning stroke occurs when the drive charge 28 is fired. The drive charge, when fired, produces gas under pressure which is directed into the interior space of the piston and which leads to a displacement of the piston 22 in the cylinder tube 20. FIG. 3 illustrates the condition of the linear drive after the completion of a tensioning stroke.
FIG. 4 shows the end of the piston 22 with the end wall according to a first embodiment of the invention. The end wall has a passage opening 40 extending in the longitudinal direction of the piston. A blow-out patch 42 is arranged on the end wall on the side facing into the interior space. The blow-out patch 42 shuts off the passage opening 40. The blow-out patch 42 is provided with points 44 of intended weakness to ensure that when the pressure in the interior space 24 of the piston 22 exceeds a predetermined maximum pressure, the passage opening 40 is cleared and the gas under pressure escapes from the interior space of the piston 22. One advantageous feature of the present invention is that if the piston 22 should jam in the initial position upon firing of the drive charge 28, excessively high gas pressure will not build up in the interior of the piston 22.
The blow-out patch 42 is made of a metallic foil press-fitted in the piston. Use of a metallic foil ensures high reproducibility of the pressure values at which the passage opening 40 is cleared because such metallic foil components can be produced with very tight tolerances and are relatively unaffected by changes in temperature. Moreover, by making the blow-out patch 42 from metallic foil, fragmentation of the blow-out patch when the passage opening is cleared is avoided. Since the interior space in the piston 22 is sealed off completely by the blow-out patch 42 and by the seal ring 30, the entire gas pressure produced by the drive charge 28 is optimally converted into a tensioning stroke.
FIG. 5 shows the end of the piston 22 with the end wall according to a second embodiment of the invention. The blow-out patch 42 is made of metallic foil and is provided with a tubular skirt 50. The skirt 50 extends through the passage opening and has free axial end which is crimped over the outer side of the end wall. In this manner, the blow-out patch 42 is reliably located on the end wall 26. The blow-out patch 42 has points 44 of intended weakness so that the blow-out patch 42 will clear the passage opening 40 when there is an excessively high pressure within the interior space of the piston 22.
FIG. 6 shows the end of the piston 22 with the end wall according to a third embodiment of the invention. The blow-out patch 42 is generally the same as the blow-out patch of FIG. 5, except the blow-out patch according to the third embodiment possesses a calibrated discharge opening 60. The calibrated discharge opening 60 connects the interior space 24 of the piston 22 with the passage opening and, accordingly, with the exterior space of the piston. The calibrated discharge opening 60 preferably has a diameter of the order of 0.5 mm. The discharge opening 60 is permanently open. However, because of the relatively small diameter of the discharge opening 60, the losses in pressure occurring during a tensioning stroke of the piston 22 are comparatively small. These pressure losses can be compensated for by using a higher output drive charge. The function of the calibrated discharge opening 60 is to equalize the pressure in the interior space 24 of the piston 22 and the interior space of the cylinder tube 20 when, after completion of the tensioning stroke, the piston 22 moves back to its initial position. Due to the pressure equalization in the interior space 24 of the piston 22 and in the interior space of the cylinder tube 20, it is impossible for any gas pressure to establish itself in the interior space 24 of the piston 22 and thus oppose reverse motion of the piston 22 into the initial position. Accordingly, despite the coupling of the belt drum of the belt retractor with the linear drive, belt webbing may be drawn off of the belt drum.
FIGS. 7 and 8 diagrammatically depict the end of the piston with the end wall of a linear drive constructed according to a fourth embodiment of the invention. The blow-out patch 42 is substantially the same as that of the second embodiment, except that the blow-out patch has an attachment part 51 instead of the attachment skirt. The attachment part 51 is engaged by a tear-off part 70 which has locking lugs 72 in engagement with the internal wall surface of the cylinder tube 20. The locking lugs 72 are located to allow displacement of the tear-off part 70 in a direction corresponding to the direction of motion of the piston on firing the drive charge. However, upon movement of the piston in the opposite direction, the locking lugs 72 lock on the cylinder tube. Thus, upon reverse movement of the piston 22 towards the initial position after a tensioning stroke, the tear-off part 70 is jammed in the cylinder tube 20 and the connection part 51 is ripped off the blow-out patch 42. Accordingly, the passage opening 40 is cleared and the piston 22 may move back into its initial position without any gas pressure building up in its interior space 24 which would oppose such reverse movement. As compared to the third embodiment, the design of the linear drive in accordance with the fourth embodiment offers the advantage that, below the maximum pressure set by the dimensions of the points 44 of predetermined weakness, there will be no loss of pressure after firing of the drive charge 28 since the interior space 24 of the piston 22 is completely sealed off by the blow-out patch 42 and by the seal ring 30.
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A linear drive for a belt pretensioner is provided. The linear drive includes a cylinder tube with a hollow inner space, a pyrotechnic drive charge which generates a pressurized gas, and a piston able to be displaced in the inner space of the cylinder tube under the action of the pressurized gas. The piston has a hollow interior space and an axial end having an end wall. The end wall has a passage opening which is closed by a blow-out patch.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a method for producing single wall carbon nanotubes, also known as linear fullerenes, employing unsupported metal containing catalysts, for decomposition of a C 1 to C 6 carbon feedstock such as carbon monoxide.
[0003] 2. Description of the Related Art
[0000] Multi-Walled Carbon Nanotubes
[0004] Multi-walled carbon nanotubes, or fibrils, are well-known. Typically, carbon fibrils have a core region comprising a series of graphitic layers of carbon.
[0005] Since the 1970's, carbon nanotubes and fibrils have been identified as materials of interest for a variety of applications. Submicron graphitic fibrils belong to a class of materials sometimes called vapor grown carbon fibers. Carbon fibrils are vermicular carbon deposits having diameters less than approximately 1.0μ. They exist in a variety of forms and have been prepared through the catalytic decomposition of various carbon-containing gases at metal surfaces. Such vermicular carbon deposits have been observed almost since the advent of electron microscopy. A good early survey and reference is found in Baker and Harris, Chemistry and Physics of Carbon , Walker and Thrower ed., Vol. 14, 1978, p. 83, and in Rodriguez, N., J. Mater. Research , Vol. 8, p. 3233 (1993).
[0006] Carbon fibrils were seen to originate from a metal catalyst particle which, in the presence of a hydrocarbon containing gas, became supersaturated in carbon. A cylindrical ordered graphitic core is extruded which immediately became coated with an outer layer of pyrolytically deposited graphite. These fibrils with a pyrolytic overcoat typically have diameters in excess of 0.1μ. (Obelm, A. and Endo, M., J. Crystal Growth, 32:335-349(1976).)
[0007] Tibbetts has described the formation of straight carbon fibers through pyrolysis of natural gas at temperatures of 950°-1075° C., Appl. Phys. Lett. 42(8):666(18\983). The fibers are reported to grow in two stages where the fibers first lengthen catalytically and then thicken by pyrolytic deposition of carbon. Tibbetts reports that these stages are “overlapping”, and is unable to grow filaments free of pyrolytically deposited carbon. In addition, Tibbett's approach is commercially impracticable for at least two reasons. First, initiation of fiber growth occurs only after slow carbonization of the steel tube (typically about ten hours), leading to a low overall rate of fiber production. Second, the reaction tube is consumed in the fiber forming process, making commercial scale-up difficult and expensive.
[0008] In 1983, Tennent, U.S. Pat. No. 4,663,230 succeeded in growing cylindrical ordered graphite cores, uncontaminated with pyrolytic carbon, resulting in smaller diameter fibrils, typically 35 to 700 Å (0.0035 to 0.07μ), and an ordered “as grown” graphitic surface. Tennent '230 describes carbon fibrils free of a continuous thermal carbon overcoat and having multiple graphitic outer layers that are substantially parallel to the fibril axis. They may be characterized as having their c-axes, (the axes which are perpendicular to the tangents of the curved layers of graphite) substantially perpendicular to their cylindrical axes, and having diameters no greater than 0.1 μand length to diameter ratios of at least 5.
[0009] Tennent, et al., U.S. Pat. No. 5,171,560 describes carbon fibrils free of thermal overcoat and having graphitic layers substantially parallel to the fibril axes such that the projection of said layers on said fibril axes extends for a distance of at least two fibril diameters. Typically, such fibrils are substantially cylindrical, graphitic nanotubes of substantially constant diameter and comprise cylindrical graphitic sheets whose c-axes are substantially perpendicular to their cylindrical axis. They are substantially free of pyrolytically deposited carbon, have a diameter less than 0.1 μand a length to diameter ratio of greater than 5.
[0010] Moy et al., U.S. Ser. No. 07/887,307 filed May 22, 1992, describes fibrils prepared as aggregates having various macroscopic morphologies (as determined by scanning electron microscopy) including morphologies resembling bird nests (“BN”), combed yarn (“CY”) or “open net” (“ON”) structures.
[0011] Multi-walled carbon nanotubes of a morphology similar to the catalytically grown fibrils described above have been grown in a high temperature carbon arc (Iijima, Nature 354 56 1991). (Iijima also describes arc-grown single-walled nanotubes having only a single layer of carbon arranged in the form of a linear Fullerene.) It is now generally accepted (Weaver, Science 265 1994) that these arc-grown nanofibers have the same morphology as the earlier catalytically grown fibrils of Tennent.
[0000] Single-Walled Carbon Nanotubes
[0012] As mentioned above, the Iijima method partially results in single-walled nanotubes, i.e., nanotubes having only a single layer of carbon arranged in the form of a linear Fullerene.
[0013] U.S. Pat. No. 5,424,054 to Bethune et al. describes a process for producing single-walled carbon nanotubes by contacting carbon vapor with cobalt catalyst. The carbon vapor is produced by electric arc heating of solid carbon, which can be amorphous carbon, graphite, activated or decolorizing carbon or mixtures thereof. Other techniques of carbon heating are discussed, for instance laser heating, electron beam heating and RF induction heating.
[0014] Smalley (Guo, T., Nikoleev, P., Thess, A., Colbert, D. T., and Smally, R. E., Chem. Phys. Lett. 243: 1-12 (1995)) describes a method of producing single-walled carbon nanotubes wherein graphite rods and a transition metal are simultaneously vaporized by a high-temperature laser.
[0015] Smalley (Thess, A., Lee, R., Nikolaev, P., Dai, H., Petit, P., Robert, J., Xu, C., Lee, Y. H., Kim, S. G., Rinzler, A. G., Colbert, D. T., Scuseria, G. E., Tonárek, D., Fischer, J. E., and Smalley, R. E., Science, 273: 483-487 (1996)) also describes a process for production of single-walled carbon nanotubes in which a graphite rod containing a small amount of transition metal is laser vaporized in an oven at about −1200° C. Single-wall nanotubes were reported to be produced in yields of more than 70%.
[0016] Each of the techniques described above employs (1) solid carbon as the carbon feedstock. These techniques are inherently disadvantageous. Specifically, solid carbon vaporization via electric arc or laser apparatus is costly and difficult to operate on the commercial or industrial scale.
[0017] Supported metal catalysts for formation of SWNT are also known. Smalley (Dai., H., Rinzler, A. G., Nikolaev, P., Thess, A., Colbert, D. T., and Smalley, R. E., Chem. Phys. Lett. 260: 471-475 (1996)) describes supported Co, Ni and Mo catalysts for growth of both multi-walled nanotubes and single-walled nanotubes from CO, and a proposed mechanism for their formation.
[0018] However, supported metal catalysts are inherently disadvantageous, as the support is necessarily incorporated into the single-walled carbon nanotube formed therefrom. Single-walled nanotubes contaminated with the support material are obviously less desirable compared to single-walled nanotubes not having such contamination.
OBJECTS OF THE INVENTION
[0019] It is thus an object of the present invention to provide a method of producing single-walled carbon nanotubes which employs a gaseous carbon feedstock.
[0020] It is an object of this invention to provide a method of producing single-walled carbon nanotubes which employs a gas phase, metal containing compound which forms a metal containing catalyst.
[0021] It is also an object of the invention to provide a method of producing single-walled carbon nanotubes which employs an unsupported catalyst.
[0022] It is a further object of this invention to provide a method of producing single-walled carbon nanotubes which employs a gaseous carbon feedstock and an unsupported gas phase metal containing compound which forms a metal containing catalyst.
SUMMARY OF THE INVENTION
[0023] The invention relates to a gas phase reaction in which a gas phase metal containing compound is introduced into a reaction mixture also containing a gaseous carbon source. The carbon source is typically a C 1 through C 6 compound having as hetero atoms H, O, N, S or Cl, optionally mixed with hydrogen. Carbon monoxide or carbon monoxide and hydrogen is a preferred carbon feedstock.
[0024] Increased reaction zone temperatures of approximately 400° C. to 1300° C. and pressures of between ˜0 and ˜100 p.s.i.g., are believed to cause decomposition of the gas phase metal containing compound to a metal containing catalyst. Decomposition may be to the atomic metal or to a partially decomposed intermediate species. The metal containing catalysts (1) catalyze CO decomposition and (2) catalyze SWNT formation. Thus, the invention also relates to forming SWNT via catalytic decomposition of a carbon compound.
[0025] The invention may in some embodiments employ an aerosol technique in which aerosols of metal containing catalysts are introduced into the reaction mixture. An advantage of an aerosol method for producing SWNT is that it will be possible to produce catalyst particles of uniform size and scale such a method for efficient and continuous commercial or industrial production. The previously discussed electric arc discharge and laser deposition methods cannot economically be scaled up for such commercial or industrial production.
[0026] Examples of metal containing compounds useful in the invention include metal carbonyls, metal acetyl acetonates, and other materials which under decomposition conditions can be introduced as a vapor which decomposes to form an unsupported metal catalyst.
[0027] Catalytically active metals include Fe, Co, Mn, Ni and Mo. Molybdenum carbonyls and Iron carbonyls are the preferred metal containing compounds which can be decomposed under reaction conditions to form vapor phase catalyst. Solid forms of these metal carbonyls may be delivered to a pretreatment zone where they are vaporized, thereby becoming the vapor phase precursor of the catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 illustrates a reactor capable of producing SWNT.
[0029] FIG. 2 illustrates the vaporizer component of the reactor described in FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] It has been found that two methods may be employed to form SWNT on unsupported catalysts. The first method is the direct injection of volatile catalyst. The direct injection method is described is copending application Ser. No. 08/459,534, incorporated herein by reference.
[0031] Direct injection of volatile catalyst precursors has been found to result in the formation of SWNT using molybdenum hexacarbonyl [Mo(CO) 6 ] and dicobalt octacarbonyl [CO 2 (CO) 8 ] catalysts. Both materials are solids at room temperature, but sublime at ambient or near-ambient temperatures—the molybdenum compound is thermally stable to at least 1500, the cobalt compound sublimes with decomposition “Organic Syntheses via Metal Carbonyls,” Vol. 1, I. Wender and P. Pino, eds., Interscience Publishers, New York, 1968, p. 40).
[0032] The second method uses a vaporizer to introduce the metal containing compound ( FIG. 2 ).
[0033] In one preferred embodiment of the invention, the vaporizer 10 , shown at FIG. 2 , comprises a quartz thermowell 20 having a seal 24 about 1″ from its bottom to form a second compartment. This compartment has two ¼″ holes 26 which are open and exposed to the reactant gases. The catalyst is placed into this compartment, and then vaporized at any desired temperature using a vaporizer furnace 32 . This furnace is controlled using a first thermocouple 22 .
[0034] A metal containing compound, preferably a metal carbonyl, is vaporized at a temperature below its decomposition point, reactant gases CO or CO/H 2 sweep the precursor into the reaction zone 34 , which is controlled separately by a reaction zone furnace 38 and second thermocouple 42 .
[0035] Although applicants do not wish to be limited to a particular theory of operability, it is believed that at the reactor temperature, the metal containing compound is decomposed either partially to an intermediate species or completely to metal atoms. These intermediate species and/or metal atoms coalesce to larger aggregate particles which are the actual catalyst. The particle then grows to the correct size to both catalyze the decomposition of CO and promote SWNT growth. In the apparatus of FIG. 1 , the catalyst particles and the resultant carbon forms are collected on the quartz wool plug 36 .
[0036] Rate of growth of the particles depends on the concentration of the gas phase metal containing intermediate species. This concentration is determined by the vapor pressure (and therefore the temperature) in the vaporizer. If the concentration is too high, particle growth is too rapid, and structures other than SWNT are grown (e.g., MWNT, amorphous carbon, onions, etc.).
[0037] Examples 5 and 6 show many areas of SWNT along with MWNT and other carbon structures. Mo particles ranged from <1-10 nm. In Example 4, mainly MWNT were formed along with other structures of carbon. Mo particles ranged from ˜1-50 nm. Presumably, the particles generated in Examples 5 and 6 were the right size to promote SWNT growth over the other forms possible. In Example 4, particle sizes favored growth of MWNT and other forms.
EXAMPLES
Example 1
[0038] In a direct injection process, the catalyst compartment was loaded with ˜40 mg Molybdenum hexacarbonyl [Mo(CO) 6 ]which has been ground to ˜−100 mesh. The reactor was heated to 900° C. under an argon flow. Argon was then replaced with CO at atmospheric pressure at a flow of ˜0.8 SLM and the catalyst was injected.
[0039] The flow of CO was continued for 30 min. at 900° C., after which it was replaced by argon, and the reactor furnace turned off. After cooling to ambient temperature, the entire contents of the reactor including the quartz wool plug which had been tared prior to the run, was emptied into a tared plastic bag. The quartz wool plug was blackened, but the yield of carbon growth (wgt C/wgt catalyst) was <1.
[0040] A specimen for Transmission Electron Microscopy (TEM) was prepared by shaking the quartz wool plug in ethanol in a glass vial and ultrasounding the ethanol for ˜2 min. This procedure dispersed the black particles from the quartz wool. A TEM grid was prepared by evaporating several drops of this dispersion onto a carbon-coated copper grid.
[0041] Examination of the grid in the TEM showed a mixture of particles and carbon nanotubes, both MW and SW. Particles varied from ˜1-several hundred nm and were shown to be Mo by dispersive X-ray analysis. The MWNT ranged from ˜4-10 nm diameter. Fishbone fibrils (10-50 nm diameter) were also formed.
[0042] Examination of the grid also showed several areas containing SWNT. Diameters ranged between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 2
[0043] The procedure of Ex. 1 was used to produce a mixture of Mo particles and carbon structures including both MWNT and SWNT. Catalyst charge [MO(CO) 6 ] was ˜8 mg. SWNT yield was <50% of all nanotubes produced.
Example 3
[0044] The procedure of Example 1 was used to grow SWNT using ˜22 mg CO 2 (CO) 8 as catalyst. TEM analysis revealed Co particles to be the major component. MWNT and SWNT ranging in diameter from 1-2 nm were also formed. Estimated yield of SWNT was <25% of the nanotubes formed.
Example 4
[0045] A simulated aerosol reactor ( FIG. 1 ) was used to produce SWNT. As the catalyst sublimed in the vaporizer, the vapors were swept by the reactant gases into the reaction section where they underwent immediate thermal decomposition to Mo atoms and Co. It is theorized that the Mo atoms aggregated and promoted growth of carbon structures, including SWNT. These were caught on the quartz wool plug.
[0046] Approximately 20 mg of Mo(C) 6 was loaded into the vaporizer. Under argon at atmospheric pressure, the reactor section was heated to 900° C. while keeping the vaporizer at ambient temperature. The argon stream was then changed to CO @˜0.8 SLM and H 2 @˜0.08 SLM, and while maintaining 900° in the reactor, the vaporizer temperature was raised to 70° C. Over the course of the run (1.5 hrs) the vaporizer temperature rose to 80° C. due to heat from the reactor furnace. The vapor pressure of Mo(CO) 6 varied from 0.6-10 torr.
[0047] TEM specimens were made by the same procedure as Ex. 1. TEM examination showed mainly very small particles of Mo ranging from ˜1-10 nm. Also produced were amorphous carbon structures and MWNT with diameters ˜4 nm. SWNT with diameters ˜1.5 nm were also produced, but in low yield.
Example 5
[0048] A procedure similar to Ex. 4 where ˜20 mg Mo(CO) 6 was loaded in the vaporizer. With the reactor at atmospheric pressure at 900° C., the vaporizer temperature was set at 40° C. and CO was fed to the system @˜0.8 SLM. Over the course of the run (1.5 hrs) the vaporizer temperature rose to 57° C. For this temperature span, the vapor pressure of Mo(CO) 6 ranged from 0.6-2 torr.
[0049] TEM examination showed mainly Mo nanoparticles 1-10 nm in diameter along with various carbon structures. These included amorphous carbon and MWNT with diameters of 4-10 nm. However, also produced were SWNT with diameters varying from ˜1-3 nm. Estimated yield of SWNT was <20% of the nanotubes produced.
Example 6
[0050] Using the procedure of Exs. 4-5, ˜20 mg Mo(CO) 6 was vaporized at 38-41° C. into the reactor zone which was set at 900° C. The feed gas comprised CO @0.8 SLM and H 2 @0.08 SLM and was fed at atmospheric pressure for 2.0 hrs. Vapor pressure of catalyst was nearly constant at ˜0.6 torr.
[0051] TEM examination showed the presence of Mo nanoparticles, many ˜1 nm diameter. The usual amorphous carbon and MWNT with diameters ranging from 4-10 nm were seen. However, SWNT, 1-3 nm in diameter were also produced at a yield of ˜50% of the nanotubes produced.
Example 7
[0052] Examples 1-6 are summarized in Table I. Precursor was obtained as a powder from ALFA/AESAR, Research Chemicals and Materials. They were ground under an argon blanket to ˜−100 mesh.
CATALYST FEEDSTOCK REACTOR VAPORIZER Run # PRECURSOR COMPOSITION TEMP TEMP STEM SWNT 1* Mo(CO) 6 CO-100% 900° C. NA Mix of <50% particles and MWNT/SWNT 2* Mo(CO) 6 CO-100% 900° C. NA Same as <50% above; X-ray showed no Fe 3* Co 2 (CO) 8 CO-100% 900° C. NA Mostly <25% particles, some SWNT strings 4** Mo(CO) 6 CO-90% 900° C. 70-80° C. Mostly trace H 2 -10% particles, MWNT 5** Mo(CO) 6 CO-100% 900° C. 40-57° C. Mostly <20% particles and MWNT, some SWNT 6** Mo(CO) 6 CO-90% 900° C. 38-41° C. Particles, ˜50% H 2 -10% few MWNT, more SWNT *Direct Injection Method **Simulated Aerosol Method
Example 8
[0053] Ferrocene (C 5 H 5 ) 2 Fe is substituted for the molybdenum hexacarbonyl in the procedure of Example 2 at an appropriate vapor pressure and temperature.
[0054] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0055] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 9
[0056] Ferrocene (C 5 H 5 ) 2 Fe is substituted for the molybdenum hexacarbonyl in the procedure of Example 6 at an appropriate vapor pressure and temperature.
[0057] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0058] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 10
[0059] Methylcyclopentadienyl manganese tricarbonyl (CH 3 C 5 H 4 )Mn(CO) 3 is substituted for the molybdenum hexacarbonyl in the procedure of Example 2 at an appropriate vapor pressure and temperature.
[0060] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0061] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 11
[0062] Methylcyclopentadienyl manganese tricarbonyl (CH 3 C 5 H 4 )Mn(CO) 3 is substituted for the molybdenum hexacarbonyl in the procedure of Example 6 at an appropriate vapor pressure and temperature.
[0063] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0064] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 12
[0065] Cyclopentadienyl cobalt dicarbonyl (C 5 H 5 )CO(CO) 2 is substituted for the molybdenum hexacarbonyl in the procedure of Example 2 at an appropriate vapor pressure and temperature.
[0066] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0067] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 13
[0068] Cyclopentadienyl cobalt dicarbonyl (C 5 H 5 )Co(CO) 2 is substituted for the molybdenum hexacarbonyl in the procedure of Example 6 at an appropriate vapor pressure and temperature.
[0069] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0070] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 14
[0071] Nickel dimethylglyoxime (HC 4 H 6 N 2 O 2 )Ni is substituted for the molybdenum hexacarbonyl in the procedure of Example 2 at an appropriate vapor pressure and temperature.
[0072] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0073] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
Example 15
[0074] Nickel dimethylglyoxime (HC 4 H 6 N 2 O 2 )Ni is substituted for the molybdenum hexacarbonyl in the procedure of Example 6 at an appropriate vapor pressure and temperature.
[0075] Examination of the grid in the TEM shows a mixture of particles and carbon nanotubes, both MW and SW. Particles vary from ˜1-several hundred nm. The MWNT ranges from ˜4-10 nm diameter.
[0076] Examination of the grid also shows several areas containing SWNT. Diameters range between 1-2 nm. TEM estimate of the yield of SWNT was <50% of the carbon formed.
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A process for producing hollow, single-walled carbon nanotubes by catalytic decomposition of one or more gaseous carbon compounds by first forming a gas phase mixture carbon feed stock gas comprising one or more gaseous carbon compounds, each having one to six carbon atoms and only H, O, N, S or Cl as hetero atoms, optionally admixed with hydrogen, and a gas phase metal containing compound which is unstable under reaction conditions for said decomposition, and which forms a metal containing catalyst which acts as a decomposition catalyst under reaction conditions; and then conducting said decomposition reaction under decomposition reaction conditions, thereby producing said nanotubes.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of application Ser. No. 12/461,242 filed Aug. 5, 2009, which is a Continuation of application Ser. No. 11/241,957 filed Oct. 4, 2005, which is a Divisional of application Ser. No. 10/765,972 filed Jan. 29, 2004, which is a Continuation of application Ser. No. 09/601,313 filed Sep. 11, 2000, which is a U.S. National Stage application from PCT/CH99/00586 filed Dec. 7, 1999, which claims priority from Swiss Patent Application No. 2448/98 filed Dec. 10, 1998. The disclosures of the prior applications are hereby incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a plastic object for use in personal hygiene and to a method of producing the plastic object.
2. Description of Related Art
A plastic object of this type takes the form, for example, of a toothbrush. Toothbrushes are mass-produced articles and must therefore allow cost-effective production. Toothbrushes made of a single plastic material and toothbrushes made of two plastic components, which are produced for example by the two-component injection-molding process, are known. In the latter case, the toothbrush comprises two plastic parts: a first plastic part made of a first plastic material, for example polypropylene, extends from the handle of the toothbrush up to the brush head and has interconnected recesses. A second plastic part made of a second plastic material, for example thermoplastic elastomer, fills the recesses of the first plastic part. These two plastic materials bond with one another at the surface where the two plastic parts touch. In comparison with a toothbrush made of only one plastic material, this provides greater scope for design. Since, however, the two plastic materials have to bond with one another during the injection-molding operation, there are restrictions in the selection of the plastic materials and consequently in the design of the toothbrush.
This problem also affects other plastic objects for use in personal hygiene comprising at least two parts made of different plastic materials, such as for example containers or closure caps for containers intended for personal-hygiene preparations and substances, or for medical and dental preparations. There are restrictions in the selection of materials for the two parts in the case of such plastic objects as well.
SUMMARY OF THE INVENTION
The present invention is based on the object of providing a plastic object of the type mentioned at the beginning with which varied design is possible along with cost-effective production.
This object is achieved according to aspects of the invention. The method of producing such a plastic object is distinguished according to aspects of the invention. Preferred developments of the plastic object according to the invention and of the method according to the invention form additional aspects of the invention.
The fact that the two parts of the plastic object are formed by at least two molded parts consisting of different plastic materials which do not bond with one another during the injection-molding operation and are joined to one another in particular by a non-positive and/or positive fit means that there are many possibilities for an expedient design of the plastic object. Plastic materials of different chemical character can be used. They may differ to a greater or lesser extent in their structural formula and their chemical components. At the surfaces where they touch, there do not have to be any chemical or physical bonds, for example in the form of bridge formations or van der Waals forces, between the plastic materials. The frictional forces alone between the molded parts in the joint, preferably constructed in the manner of a shrink fit, are adequate to join the two molded parts firmly to one another. The positive fit realized by means of parts engaging in one another at the surfaces where the two molded parts touch prevents gaps into which water and contaminants can penetrate, or which can even lead to rupture, from forming between the two molded parts during the shrinking operation.
Therefore, in the case of a toothbrush for example, plastic materials with advantageous properties can be used at the right place. The one molded part may consist, for example, of polypropylene (polypropylene is available inexpensively, is flexible, chemically resistant but not completely transparent), while styrene acrylonitrile (SAN) (likewise inexpensive, transparent, esthetic) may be chosen for example for the other molded part. The molded part bearing the brush head is advantageously produced from polypropylene, since polypropylene is resistant to the often aggressive substances of the tooth-cleaning agents.
The two plastic materials advantageously have a different shrinkage behavior, since a firm shrink fit can be achieved more easily in this way. In this case, that molded part which is produced from plastic material with the lower degree of shrinkage is advantageously produced in a first step. The second molded part is produced from plastic material with the greater degree of shrinkage in a second step, thereby achieving a natural pressure of the second plastic material pressing against the first plastic material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below with reference to the drawing, in which:
FIG. 1 shows a first exemplary embodiment of a toothbrush comprising two molded parts in side view and partially in longitudinal section;
FIG. 2 shows the toothbrush according to FIG. 1 in plan view;
FIG. 3 shows the toothbrush according to FIG. 1 in a view from below;
FIG. 4 shows a first molded part of the toothbrush according to FIG. 1 in elevation and partially in longitudinal section;
FIG. 5 shows the molded part according to FIG. 4 in plan view;
FIG. 6 shows a second molded part of the toothbrush according to FIG. 1 in plan view;
FIG. 7 shows a section along line VII-VII in FIG. 6 ;
FIG. 8 shows a joint of the two molded parts according to FIG. 1 on an enlarged scale;
FIG. 9 shows a section along line IX-IX in FIG. 2 on an enlarged scale;
FIG. 10 shows a second exemplary embodiment of a toothbrush comprising two molded parts in side view;
FIG. 11 shows the toothbrush according to FIG. 10 in plan view; and
FIG. 12 shows the toothbrush according to FIG. 10 on an enlarged scale, in side view and partially in section, a closure part for closing a handle cavity from the remaining part of the toothbrush being represented separately.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to FIGS. 1 to 3 , a toothbrush 1 has a first molded part 2 , which bears a brush head 3 in its front region 2 a . The first molded part 2 , consisting of a plastic material A, is enclosed over a portion of its length, to be specific its rear handle region 2 b , by a second molded part 4 , consisting of a plastic material B, and is non-positively joined to the latter in the manner of a shrink fit. The plastic materials A and B are plastic materials of a kind which do not bond with one another during the injection-molding operation at the surfaces where they touch.
For better illustration, the two molded parts 2 , 4 are represented separately from one another in FIGS. 4 to 7 . The two molded parts 2 , 4 have—as described further below—in the region where they touch diametrically opposite projections and recesses engaging in one another, by means of which a positive fit of the two molded parts 2 , 4 is realized in addition to the non-positive fit of the same. It goes without saying that this joint is only produced during the injection-molding operation, in which one of the molded parts is injection-molded in a first step and then the other molded part is injection-molded around or into the first part in a second step. With the different degree of shrinkage of the two molded parts 2 , 4 , that molded part which is to be produced from plastic material with a lower degree of shrinkage is advantageously injection-molded first. In the second step, injection-molding of the other molded part takes place from plastic material with a greater degree of shrinkage, whereby a natural pressure of the second plastic material pressing against the first plastic material is produced.
The second molded part 4 , represented individually in FIGS. 6 and 7 and essentially forming the toothbrush handle, is designed in the form of a sleeve, i.e. is provided with an internal longitudinal bore 7 , which corresponds in its shape and diameter to the rear handle region 2 b of the first molded part 2 , represented individually in FIGS. 4 and 5 . The sleeve-shaped molded part 4 has an outer surface 6 .
A front end face 8 of the sleeve-shaped second molded part 4 is assigned to an offset surface 9 of the first molded part 2 ( FIG. 4 ), seen in the longitudinal direction of the toothbrush. In this case, an annular, front projection 10 of the second molded part 4 protrudes into a diametrically opposite recess 11 of the first molded part 2 , which can be seen particularly well from FIG. 8 . A rear end face 14 of the sleeve-shaped second molded part 4 is assigned to an offset surface 16 of an end piece 15 of the first molded part 2 . Here, too, an annular, rear projection 17 of the second molded part 4 protrudes into a diametrically opposite recess 18 of the end piece 15 .
The second molded part 4 is provided with a cross-sectionally oval, elongate cross-bore 20 , which is arranged transversely to the longitudinal bore 7 and is intended for a diametrically opposite part 21 of the first molded part 2 , penetrating through the cross-bore 20 . The oval part 21 has an upper edge surface 22 and a lower edge surface 22 ′. The second molded part 4 is provided with offset surfaces 23 , 23 ′, which run around the cross-bore 20 and are diametrically opposite the edge surfaces 22 , 22 ′. The edge surfaces 22 , 22 ′ and the offset surfaces 23 , 23 ′ in turn form a type of projection/recess positive-fitting joint between the two molded parts 2 , 4 .
Together with outer surfaces 19 , 19 ′ ( FIG. 4 ) of the oval part 21 , the outer surface 6 of the sleeve-shaped molded part 4 forms a handle surface.
As far as the material for the two molded parts 2 , 4 is concerned, polypropylene (PP) may be advantageously chosen, for example, as the plastic material A for the first molded part 2 , while the second molded part 4 may consist, for example, of the following plastic materials B:
styrene acrylonitrile (SAN) and subgroups,
acrylonitrile-butadiene styrene (ABS) and subgroups,
polyamide (PA) and subgroups,
polycarbonate (PC) and subgroups,
polyester (PBT) and subgroups, or other transparent plastic materials not bonding with polypropylene (PP).
The respective subgroups comprise the plastic materials belonging to the corresponding family.
This combination of materials provides a special advantage. Since modern tooth-cleaning agents often contain aggressive substances, such as peppermint-oil for example, cheap plastics, such as SAN for example, are often attacked. If the first molded part 2 , bearing the brush head 3 , is made of PP, which is resistant to the aggressive substances but not completely transparent, and the second molded part 4 , comprising the handle, is made of transparent, but less resistant SAN, this special embodiment of the invention constitutes a toothbrush which can be produced cost-effectively, is resistant to the aggressive substances of the tooth-cleaning agents and is also able to be esthetically pleasing. Of course, any other resistant plastic material may be used instead of PP and one of the cheaper, and therefore generally less resistant, plastic materials mentioned above may be used, for example, instead of SAN.
With these combinations of materials, preferably the second, sleeve-shaped molded part 4 is produced first, by means of injection molding, in a first step. Subsequently, the first molded part 2 is injection-molded in a second step, the positive fit already described being produced in the region where the two molded parts 2 , 4 touch. The greater degree of shrinkage of the last-molded material A (PP) of the first part 2 has the effect of producing a natural pressure, pressing against the second part 4 consisting of material B (for example SAN), and a non-positive and positive fit of the two molded parts 2 , 4 is brought about by the projections 10 , 17 , 22 , 22 ′ engaging in recesses 11 , 18 , 23 , 23 ′, without gaps into which water and contaminants can penetrate, or which can even lead to a rupture, forming between the plastic materials A, B, which actually do not bond with one another.
As an example, a toothbrush 1 comprising two molded parts 2 , 4 has been presented and described. A different configuration of the two molded parts would be quite possible. The sleeve-shaped configuration of one of the molded parts is not absolutely necessary.
It goes without saying that a toothbrush could also have a plurality of molded parts made of plastic materials not bonding with one another during the injection-molding operation, which are joined to one another by a non-positive and/or positive fit.
Instead of the shrink fit and positive fit described, the individual molded parts, which do not enter into an adhesive or cohesive bond during the injection-molding operation, could be non-positively and/or positively joined to one another in any other way.
However, molded parts comprising two or more plastic components of which, for example, one (or more) component(s) of the one molded part cannot be bonded with one (or more) component(s) of the other molded part, could also be non-positively and/or positively joined to one another.
Represented in FIGS. 10 and 11 is a second exemplary embodiment of a toothbrush 1 ′, which likewise has two molded parts 32 , 34 consisting of different plastic materials A and B which do not bond with one another during the injection-molding operation. Here, too, the first molded part 32 forms a toothbrush part bearing the brush head 3 ′ (the bristles of the brush head 3 ′ are not represented in FIGS. 10 and 11 ; only the depressions 35 intended for anchoring tufts of bristles can be seen). The second molded part 34 forms a toothbrush handle. This is provided over part of its length with a cylindrical hollow 36 , by which a cavity 37 which is open toward the rear and can be closed by means of a closure part 38 is formed in the toothbrush handle. The second molded part 34 preferably consists of an at least partially transparent or translucent material component, for example SAN, so that various esthetically acting means (loose objects, liquid, powder, printed rollers etc.) can be visibly accommodated in the cavity 37 . The closure part 38 may be joined undetachably or detachably to the second molded part 34 . In the latter case, useful objects, such as toothpicks or ampoules with mouth wash or toothpaste, may also be accommodated, for example, in the cavity 37 .
In the case of this embodiment of a toothbrush as well, the surfaces where the two molded parts 32 , 34 touch are provided with parts 40 , 41 engaging in one another, so that the two plastic parts are brought into a non-positive and positive fit during injection molding. The parts 40 , 41 engaging in one another are formed, for example, by a projection 40 on the end face of the molded part 34 forming the handle and a diametrically opposite recess 41 on the end face of the other molded part 32 .
If the handle is produced from the transparent SAN, it is also the case with this embodiment that this handle-forming molded part 34 is preferably produced first in the injection-molding process and the molded part 32 , bearing the brush head, is subsequently injection-molded, for example from more resistant polypropylene.
Both the bristle-bearing part of the toothbrush and the handle may have parts consisting of further material components. For example, a depression for a thumb rest 42 , of a further material component, for example a thermoplastic elastomer (TPE), may be provided, for example, in the molded part 34 .
The toothbrush shown in FIG. 12 corresponds to the toothbrush 1 ′ according to FIGS. 10 and 11 , but is represented on an enlarged scale in comparison with FIG. 10 and partially in section (the same parts are denoted by the same reference numerals). This toothbrush 1 ′ is intended for the insertion of variously filled ampoules 45 , for which a holder 46 of an elastically compliant plastic is present in the front region of the hollow 36 . The closure part 38 is provided on the inside with an elastically compliant counterholder 38 ′. The ampoule 45 is held both radially and axially in its position by the two holders 46 , 38 ′. The holder 46 may, for example, be injection-molded from the same plastic (preferably from PP) and in the same step with the molded part 32 bearing the brush head 3 ′ (the joining channel present for this is denoted by 47 in FIG. 12 ). From the same plastic material and in the same step, a cross-bore 48 may also be filled in the molded part 34 injection-molded first (for example from SAN), whereby the thumb rest 42 is formed on the outer side of the handle.
The ampoules 45 may contain various esthetically acting objects (loose or suspended in a liquid), liquid, powder etc.
As already mentioned, other plastic objects similar to toothbrushes for use in personal hygiene could be formed from at least two molded parts which consist of different plastic materials which do not bond with one another during the injection-molding operation, and which are joined to one another by a non-positive and/or positive fit. For example, in the case of containers or closure caps for containers which are intended for personal-hygiene preparations and substances, or for medical and dental preparations, plastics with advantageous properties could likewise be used at the right place in cost-effective production.
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A unitary two component article for personal hygiene, such as a toothbrush, wherein the same is formed by injection molding of two differing plastic materials. The plastics do not adhesively or chemically bond to each other. The two differing plastic parts of the toothbrush are mechanically connected, such as by interfitting portions of the two plastic components or by shrinking one plastic component about the other.
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BACHGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sinker bar for a hydrocarbon well apparatus operated by means of a cable.
2. Description of the Prior Art
In the field of oil exploration and extraction, it is often necessary to lower various apparatuses down a hydrocarbon well. Such apparatuses are suspended from a cable driven at the surface by means of a winch.
This applies, for example, when a perforator apparatus is operated to bring a well into operation.
It is also known to perform monitoring or diagnosis functions in hydrocarbon wells that are in operation by lowering measuring apparatuses down such wells. By way of example, one such apparatus is described in French patent application No. 97.03422.
It is also known to use sinker bars whose weight adds to that of the apparatus to make it easier to lower the apparatus down the well. Such sinker bars are often necessary to balance the force, resulting from the pressure prevailing in the well, exerted on the cross-section of the cable.
Sinker bars also make it possible to overcome friction against the inside surface of the well due to the centralizer devices of the apparatus. The cross-section of the apparatus may be smaller than the cross-section of the well and centralizer devices may be used to hold the apparatus on the axis of the well. This applies in particular for inclined wells.
Finally, sinker bars are also effective to exert a sufficient tension on the cable used for operating the apparatus.
Known sinker bars are in the form of a tube provided with a thread at each end. A sinker bar or a set of assembled-together sinker bars is thus screwed at its top end to a cable head and at its bottom end to the apparatus. The operations of screwing and unscrewing sinker bars constitute a first drawback of known devices.
In addition, the cable for operating the apparatus is also used for providing an electrical connection between the apparatus and the surface, e.g. for transmitting data. An electrical connection must therefore be established through sinker bars which are disposed between the apparatus and the cable head. Sinker bars must therefore be fluid-tight and capable of withstanding the pressures prevailing in the well.
As a result, electrical contacts must be present to provide connections between sinker bars, and also between the apparatus and the cable, and seals are required to make the sinker bars fluid-tight. This gives rise to problems of reliability due to loss of insulation or to faulty electrical continuity.
Finally, in inclined wells, a special adapter must be added to provide a ball joint between the sinker bars and the apparatus. Such an arrangement is necessary to avoid the need to center sinker bars, which would require centralizer devices of large mechanical strength.
SUMMARY OF THE INVENTION
There is provided according to the invention a sinker bar for use with a well apparatus connected to an operating cable through a cable head, comprising a bar provided with a longitudinal slot, said slot being adapted to permit lateral engagement of said bar onto said cable, and including first connection means at one of its ends for connection to said cable head.
Thanks to their longitudinal slots, the sinker bars can be mounted on the cable above the member forming the cable head. The cable head can be connected to the apparatus by any appropriate means, in particular by screws, using threads which are provided in existing apparatuses.
A first advantage of the invention is that it eliminates all problems of sealing and electrical contact associated with known sinker bars.
In a particular embodiment, the sinker bar includes at its other end second connection means for connection to a member forming a fishing head.
Fishing heads are known. In the prior art, they comprise members provided with means enabling the apparatus to be extracted without using a cable. Such fishing heads are disposed at the top end of the assembly constituted by the apparatus and its sinker bars, where said assembly is connected to the cable.
Thus, it is also possible to provide for using a fishing head with sinker bars of the invention. Nevertheless, the fishing head is now above the bottom end of the cable, on top of the sinker bars.
Advantageously, the first or second connection means are twist-lock means adapted to engage complementary twist-lock means of said members.
This makes the assembling much simpler and quicker than with the threaded prior art sinker bars.
More particularly, the twist-lock means may comprise a flat twist-lock head adapted to be inserted behind at least one shoulder of said member and to be locked by said shoulder after rotating through about one-fourth of a turn, and locking means for preventing said rotation.
Naturally, the inverse configuration could be adopted, with the twist-lock means then comprising at least one shoulder adapted to receive and lock a twist-lock head of said member.
In practice, it is possible to adopt a combined solution in which the sinker bar is provided with a twist-lock head at one end and with a twist-lock shoulder at its other end. All of the bars are then identical and can be assembled one after another.
Also, in a particular embodiment, said connection means are ball joint means.
There is thus no longer any need, as in the prior art, to provide a ball joint adapter since the axes of two successive sinker bars can be slightly offset in deviated wells.
More particularly, the connection means may include a substantially spherical surface adapted to engage a complementary surface of said member.
When using twist-lock or connection means, the twist-lock means can then possess clearance to make ball joint operation possible.
The invention also provides a method of installing a sinker bar for a hydrocarbon well apparatus operatively connected to a cable through a cable head, comprising the step of engaging the sinker bar laterally onto said cable above the cable head by inserting the cable through a longitudinal slot provided in said bar.
BRIEF DESCRIPTION OF THE DRAWINGS
A particular embodiment of the invention is described below by way of non-limiting example and with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a perspective view of an assembly constituted by a fishing head, a sinker bar, and a cable head;
FIG. 2 is a section view on line II—II of FIG. 3 through said assembly after it has been assembled;
FIG. 3 is a section view on line III—III of FIG. 2;
FIG. 4 is a section view on line IV—IV of FIG. 2;
FIG. 5 is an elevation view on a larger scale of the fishing head of FIG. 1;
FIG. 6 is a section view on line VI—VI of FIG. 5;
FIG. 7 is a bottom view of the fishing head of FIG. 5;
FIG. 8 is a perspective view;
FIG. 9 is an elevation view of the sinker bar of FIG. 1;
FIG. 10 is a section view on line X—X of FIG. 9;
FIG. 11 is a bottom view of the sinker bar of FIG. 9;
FIG. 12 is a top view of the sinker bar;
FIG. 13 is a perspective view of the top endpiece of the sinker bar of FIG. 9;
FIG. 14 is a perspective view of its bottom endpiece;
FIG. 15 is an axial section view of the cable head of FIG. 1;
FIG. 16 is a perspective view of the top endpiece of the cable head; and
FIG. 17 is a top view of the cable head of FIG. 15 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a fishing head 1 , a sinker bar 2 , and a cable head 3 . The sinker bar 2 itself comprises a top endpiece 4 , a body 5 , and a bottom endpiece 6 . Similarly, the cable head 3 comprises a top endpiece 7 and a body 8 .
In normal operation, the fishing head 1 , one or more sinker bars 2 (or none), and the cable head 3 are assembled together as shown in FIGS. 2 to 4 and are disposed substantially in the longitudinal direction of the well, with the fishing head 1 on the uphole side and the cable head on the downhole side. Below, the term “top” is used for the lefthand side of the figures (uphole) and “bottom” for the righthand side (downhole).
A threaded bore 9 formed inside the body 8 of the cable head 3 is provided for securing to the bottom of that assembly a hydrocarbon well apparatus, not shown, which may be constituted in particular by a perforator apparatus or a measuring apparatus. A cable, not shown, adapted for operating the apparatus as conventional in the art (i.e. the apparatus is suspended from the cable and hence displaceable through the well by the cable, and electrically operated by the same), has its lower end fixed in conventional manner to the cable head 3 . The cable passes through the sinker bar(s) 2 and then through the fishing head 1 , and at the surface it is wound on a winch, not shown, located near the well-head.
The fishing head 1 is shown in detail in FIGS. 5 to 7 . FIG. 8 shows only the body 10 of the fishing head. The body 10 is substantially axisymmetrical with an axial bore 11 through which the operating cable passes.
The top portion 12 of the body 10 is conical, having a shoulder 13 that faces downwards. The shoulder 13 makes it possible to take hold of the assembly constituted by the apparatus, the cable head, and the sinker bars in order to extract it from the well, should that be necessary.
The bottom portion 14 of the body 10 has a downwardly open cavity 15 for receiving the head of a sinker bar or of the cable head, and as described below. The top end wall of the cavity 15 is spherical and forms the female portion of a ball joint.
During manufacture of the body 10 of the fishing head 1 , two orifices 16 are pierced through the wall of the cavity 15 . Closure pieces 17 are subsequently welded in these orifices, which pieces project into the inside of the cavity 15 to form upwardly-directed shoulders 18 . It is shown hereinafter that these shoulders 18 are used as an engagement surface for the above-mentioned heads of the sinker bars or of the cable head.
The body 10 is provided with a hole 19 whose axis is substantially parallel to the axis of the body. The hole 19 is open at its bottom end and opens out into the cavity 15 . A locking finger 20 is disposed in the hole 19 so as to be capable of projecting into the cavity 15 towards which it is urged by a spring 21 bearing at one end against the finger 20 and at its other end against the end wall of the hole 19 . Finally, a lug 22 secured to the finger 20 and extending substantially perpendicularly to the axis thereof projects outside the body 10 via a longitudinal slot 23 . It is shown below how the finger 20 serves to lock the head of a sinker bar or of the cable head in the cavity 15 .
A sinker bar as shown in FIGS. 9 to 12 is made up of three welded-together portions. The central portion 24 provides the required weight proper and is constituted by a bar 25 having a longitudinal slot 26 of generally U-shaped cross-section extending across its entire length. The width of slot 26 is such as to permit passage of the cable therethrough until engagement of the cable with the bottom surface of the slot. Thereby the central portion 24 can be laterally mounted onto the cable.
The top endpiece 27 of the sinker bar is a member that is substantially axisymmetrical, having a longitudinal slot 28 in line with the slot 26 . At its end, the endpiece 27 forms a head 29 provided with two lateral projections 30 that form downwardly-facing shoulders 31 .
The head 29 also includes a notch 32 which serves to receive the end of a locking finger 20 , as described below. Finally, the upwardly-facing surface 33 of the head 29 is substantially spherical.
The third element of the sinker bar is a bottom endpiece 34 . The bottom endpiece 34 is similar to the body 14 of the fishing head 1 and is therefore not described. The same references have been used for corresponding members in the figures showing the sinker bar and the figures showing the fishing head.
As mentioned above, the cable head 3 comprises an endpiece 7 and a body 8 , the body having a thread 9 for connection to the apparatus. These two elements are welded together and include conventional means for receiving and securing the end of the operating cable.
The endpiece 7 is similar to the endpiece 27 of the sinker bar and the same reference numerals are used for corresponding elements in the figures showing the sinker bar and those showing the cable head endpiece.
However, it should be observed that the top endpiece 7 is not slotted like the endpiece 27 , but is provided with an axial hole 35 opening out into the tubular body 8 of the cable head.
The operation of the invention is described below.
The fishing head 1 is initially engaged on the operating cable and the electrical connection whose end is subsequently fixed in known manner to the cable head 3 . The fishing head may optionally be fixed directly to the cable head, as described below.
It is also possible to install one or more sinker bars. This is done by raising the fishing head so as to release an appropriate length of cable, and then placing said length of cable in the slot 26 of the sinker bar. Thereafter the bottom portion of the sinker bar is fixed to the cable head, and finally the fishing head is fixed to the top portion of the sinker bar.
Both of these fixing operations are performed in the same manner, so only the operation of fixing the sinker bar to the cable head will be described.
To this end, the head 29 of the endpiece 3 is engaged between the pieces 17 of the sinker bar until the shoulders 31 go beyond the shoulders 18 . During this operation, the finger 20 is pushed back into the hole 19 of the sinker bar against the action of the spring 21 .
The sinker bar is then rotated through one-fourth of a turn until the finger 20 comes level with the notch 32 and is engaged therein under thrust from the spring 21 . The sinker bar is thus locked and prevented from rotating by the finger 20 engaged in the notch 32 , and is prevented from moving in translation by the shoulders 31 engaging the shoulders 18 .
Nevertheless, it will be observed that such engagement takes place only when traction is exerted on the sinker bar. Sufficient clearance is provided between the sinker bar and the cable head endpiece to allow for a small amount of relative axial movements between these two elements by co-operation between the spherical surfaces 33 of the cable head and 36 of the end wall of the cavity 15 .
Finally, the fishing head is fixed to the sinker bar in the same manner.
To disassemble the sinker bar, the lug 22 is pushed against the action of the spring 21 so as to extract the finger 20 from the notch 32 . The sinker bar is then free to rotate and it is rotated through one-fourth of a turn so as to offset the shoulders 18 and 31 , thereby enabling the sinker bar to be extracted.
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The invention provides a sinker bar for use with a hydrocarbon well apparatus connected to an operating cable through a cable head. The sinker bar includes a bar provided with a longitudinal slot. This slot is adapted to permit lateral engagement of the bar onto the cable, and to connect at one of its ends at the cable head. The bar may also be adapted to connect at its other end to a fishing head. The connection may be twist locked. The invention is applicable in particular with production logging apparatus.
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This application is a divisional application of application Ser. No. 12/199,604, filed on Aug. 27, 2008, and which will issue on May 29, 2012 as U.S. Pat. No. 8,186,257, the disclosure of such application which is totally incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
This invention relates to the field of devices used to support and shape work-pieces and particularly to a device for supporting and cutting work-pieces.
BACKGROUND
Laminate flooring is a popular flooring product due to its ease of installment as well as its performance. Additionally, the various designs which are available for laminate flooring enhance its popularity with consumers. The designs include wood-grain patterns, slate, marble, mosaic, and granite. Additionally, a number of specialized products have been designed to ease installation of laminate flooring. Such products include transition strips, end caps, stair nosings, moldings and baseboards.
When laminates were first introduced, there was only one method of installation. The laminates were produced in a “tongue and groove” design. When installing the laminate, the tongue and grooves were glued together, then clamped and left to dry. Manufacturers have since developed flooring that requires no glue at all.
Accordingly, installation of laminate flooring has been significantly simplified. One difficult aspect of installation that remains, however, is cutting the laminate flooring to fit within a particular area. Most laminates are provided in planks that are 7-8 inches wide and about 4 foot long. Depending upon the width of a room, the final course of planks may need to be ripped to the appropriate width. Moreover, the lengths of the planks at opposing walls need to be trimmed. Additionally, miter cuts may be required to contour the planks to fit the contours of a particular room.
Traditionally, a number of different types of saws have been used to make the necessary miter and rip cuts in laminate floors. Such saws include table saws, hand saws, jig saws and circular saws. Each of these types of saws provides some advantages. A table saw gives very precise cuts and can be used to rip cut a work-piece. Additionally, table saws can be configured to provide angled cuts by angling the work-piece. Table saws, even the “portable” table saws, however, are large and heavy. Thus, an installer must either accept the difficulty in transporting the table saw near the area where the laminate is to be installed or carry each piece of laminate back and forth from the work area to the saw location. Additionally, many homeowners attempt to install a laminate floor on their own. In the event the homeowner does not own a table saw, a different approach is needed.
Hand saws are, in stark contrast to table saws, extremely mobile. Hand saws are also, however, labor intensive. Thus, while handsaws may reasonably be used to make cuts of a few feet, the large number of planks that may need to be cut for a particular installation presents a daunting challenge to those using handsaws. Moreover, handsaws are generally not as accurate as table saws.
Jig saws and circular saws are generally much more “portable” than table saws and greatly facilitate making a large number of cuts. Depending upon the particular jigs available to an installer, however, these saws still do not provide the accuracy achievable with a table saw. Thus, while professional installers may become very skilled with using a jig saw or circular saw, other users may generate an undesired amount of scrap as a result of erroneous cuts.
What is needed is a system which can be used to rip cut a work piece and to miter cut the work piece. What is further needed is a system which is portable so that it can be located at a work site. A further need is for a system that can provide the required portability while providing accurate cuts.
SUMMARY
In accordance with one embodiment of the present invention, there is provided a laminate flooring saw system which can be used for both rip cuts and miter cuts. In one embodiment the flooring saw system includes a fence, a base including a first locking member configured to cooperate with the fence to lock the fence along a first fence axis, a second locking member configured to cooperate with the fence to lock the fence along a second fence axis, the second fence axis perpendicular to the first fence axis and a support arm positioned above the base for supporting a power tool.
In accordance with another embodiment of the present invention, there is provided a portable saw system including a base, a movable support arm, a saw movable along the support arm, a first power switch proximate the saw and movable with the saw along the support arm, a second power switch that is not movable with the saw along the support arm and a third switch movable between a first position wherein application of energy to the saw is dependent upon the position of the first power switch and independent of the position of the second power switch and a second position wherein application of energy to the saw is dependent upon the position of both the first power switch and the second power switch.
In accordance with a further embodiment, a portable saw system includes a base with an articulation surface, an articulating platform configured to articulate on the articulation surface and to define a cutting axis and a pivot defining a pivot axis and pivotably connecting the articulating platform with the base, the pivot positioned such that the cutting axis intersects the pivot axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a perspective view of a laminate flooring saw system in accordance with principles of the present invention;
FIG. 2 depicts an exploded perspective view of the laminate flooring saw system of FIG. 1 ;
FIG. 3 depicts the base of the laminate flooring saw system of FIG. 1 with the fence and articulating support structure removed;
FIG. 4 depicts a perspective view of the fence of the laminate flooring saw system of FIG. 1 ;
FIG. 5 depicts a top plan view of the articulating support structure of the laminate flooring saw system of FIG. 1 ;
FIG. 6 depicts a side plan view of the articulating support structure of the laminate flooring saw system of FIG. 1 with a plunger in an extended position;
FIG. 7 depicts a side perspective view of the base pillar of the articulating support structure of the laminate flooring saw system of FIG. 1 showing a coiled power cord receptacle;
FIG. 8 depicts a side perspective view of the base pillar of the articulating support structure of the laminate flooring saw system of FIG. 1 showing a toggle switch in accordance with principles of the invention;
FIG. 9 depicts a side perspective view of the locking pillar of the articulating support structure of the laminate flooring saw system of FIG. 1 showing a rip lock button and a miter lock arm;
FIG. 10 depicts a side perspective view of the locking pillar of the articulating support structure of the laminate flooring saw system of FIG. 1 showing a rip lock release button and a female A/B switch member;
FIGS. 11-13 depict various perspective views of the power tool of the laminate flooring saw system of FIG. 1 ;
FIG. 14 shows a schematic diagram of the electrical control circuit used to alternatively enable use of a momentary power switch for making miter cuts and a toggle switch for making rip cuts in accordance with principles of the invention;
FIG. 15 depicts a top perspective view of the laminate flooring saw system of FIG. 1 with the fence removed;
FIG. 16 depicts a top perspective view of the laminate flooring saw system of FIG. 1 with the fence and the articulating support structure positioned for making a rip cut in accordance with principles of the invention; and
FIG. 17 depicts a top perspective view of the laminate flooring saw system of FIG. 1 with the fence positioned for making a miter cut and the articulating support structure positioned to make a ninety degree miter cut in accordance with principles of the invention.
DESCRIPTION
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
FIGS. 1 and 2 show a portable laminate flooring saw system 100 . The system 100 includes a base 102 , an articulating support structure 104 and a fence 106 . A power tool 108 is supported by the support structure 104 . The base 102 includes an upper table portion 110 and a sunken articulation surface 112 . Two openings 114 and 116 extend through the base 102 to provide handholds. With reference to FIG. 3 , a locking member 118 has an axis 120 that is substantially parallel to a rip edge 122 . A locking member 124 has an axis 126 that is substantially parallel to a miter edge 128 .
The sunken articulation surface 112 opens to the miter edge 128 . A wall 130 on one side of the articulation surface 112 extends inwardly from the miter edge 128 and defines a recessed area 132 . The articulation surface 112 terminates at a wall portion 134 at a curved edge portion 136 which includes a graduated angle indicator 138 . A wall 140 extends from the sunken articulation surface 112 to the upper table portion 110 . The wall 140 includes an arced portion 142 . A number of evacuation ports 144 , a pivot opening 146 and a guide slot 148 extend through the base 102 from the sunken articulation surface 112 . A lock bore 150 , which in this embodiment also extends through the base 102 , is located proximate to the curved edge portion 136 .
The fence 106 is shown in FIG. 4 . The fence 106 includes a main body 152 and a shaft 154 . The shaft 154 includes two dog holes 156 and 158 . The dog holes 156 and 158 may be used to attach accessories to the portable saw system 100 such as hold-down devices. One side 167 of the shaft 154 opens to a blade cutout 160 while the other side 169 does not incorporate a cutout. A locking mechanism 162 includes a movable dog 164 and a fixed dog 166 . A handle 168 extends outwardly from the body 152 and is operably connected to the movable dog 164 .
The articulating support structure 104 is shown in FIGS. 5 and 6 with the power tool 108 removed. The articulating support structure 104 includes an articulating base 170 with an extension 172 , a support arm base portion 174 and a pivot base portion 176 . A blade slot 178 extends through the articulating base 170 and is aligned with a pivot 180 . A base pillar 182 is located on the support arm base portion 174 and a locking pillar 184 is located on the extension 172 . A cord support arm 186 and two circular support arms 188 and 190 extend between the base pillar 182 and the locking pillar 184 . A locking boss 192 with an enlarged head 194 is located beneath the locking pillar 184 and a movable plunger 196 is shown extending from the locking pillar 184 and through the articulating base 170 .
Referring to FIGS. 7 and 8 , the base pillar 182 includes a power cord receptacle 200 and a toggle switch 202 . The power cord receptacle 200 is sized to store a coiled power cord 204 which is coiled about the cord support arm 186 . The cord support arm 186 extends outwardly from the receptacle 200 . An external power cord 206 is received into the base pillar 182 .
The locking pillar 184 is shown in FIGS. 9 and 10 . A rip lock button 210 is located on the top of the locking pillar 184 and a miter lock arm 212 is located on the outer side of the locking pillar 184 . The locking pillar 184 further includes a rip lock release button 214 and a keyed female A/B switch member 216 .
FIGS. 11 , 12 and 13 show the power tool 108 removed from the cord support arm 186 and the two circular support arms 188 and 190 . The power tool 108 in this embodiment is a circular saw including a motor housing 220 , a gear box 222 , a blade guard 224 and a handle housing 226 . The handle housing 226 includes three bores 228 , 230 and 232 sized to receive the cord support arm 186 and the two circular support arms 188 and 190 , respectively. A momentary power switch 234 and a lockout switch 236 extend out of the handle housing 226 and a grip 238 is located at the rear 240 of the handle housing 226 . A keyed male A/B switch 242 is located below the bore 232 at the rear 240 of the housing 226 . The coiled power cord 204 is received by a power port 244 located at the front portion 246 of the handle housing 226 .
The blade guard 224 is configured to receive a blade (not shown) operably connected to the power tool 108 . A connection member 250 located at the forward portion of the blade guard 224 is provided for attachment of a hold-down bracket (not shown) and two kick-back pawls 252 and 254 are located on a positionable riving knife 256 located at the rear of the blade guard 224 below a riving knife locking knob 258 . An extension 260 is pivotably attached to the lower portion of the blade guard 224 .
A schematic of the electrical system 270 of the portable saw system 100 is shown in FIG. 14 . The electrical system 270 includes the toggle switch 202 which extends from the base pillar 182 , the momentary switch 234 which extends from the handle housing 226 and an A/B switch 272 which, in this embodiment, is located in the handle housing 226 . The toggle switch 202 is positionable to apply energy to either a terminal 274 or a terminal 276 .
The terminal 274 is connected through a lead 278 to the momentary switch 234 . The momentary switch 234 is biased to contact a terminal 280 which is electrically isolated. By application of pressure, the momentary switch 234 can be positioned to contact a terminal 282 which is connected by a lead 284 to a terminal 286 associated with the A/B switch 272 . The terminal 276 associated with the toggle switch 202 is connected by a lead 290 to a second terminal 292 associated with the A/B switch 272 . The A/B switch 272 , which is biased to contact the terminal 286 , is connected to a motor 294 in the motor housing 220 by a lead 296 .
The portable saw system 100 may be operated in accordance with the following examples. In one example, operation of the portable saw system 100 begins with the fence 106 removed as shown in FIG. 15 . With reference to FIGS. 1-6 , the articulating base 170 of the articulating support structure 104 is positioned on the sunken articulation surface 112 . The pivot 180 extends through the pivot opening 146 and the locking boss 192 extends through the guide slot 148 . The miter lock arm 212 is positioned against the locking pillar 184 , thereby locking the articulating support structure 104 on the base 102 . While a number of variations are possible, the miter lock arm 212 in this embodiment pulls the enlarged head 194 of the locking boss 192 (see FIG. 6 ) upwardly against the base 102 as the miter lock arm 212 is pivoted toward the locking pillar 184 .
With further reference to FIGS. 11-13 , the power tool 108 is slidably mounted on the articulating support structure. Specifically, the circular arm 188 slidably extends through the bore 230 , the circular arm 190 slidably extends through the bore 232 and the power cord support arm 186 slidably extends through the bore 238 . When so positioned, the saw blade (not shown) attached to the power tool 108 extends into the blade slot 178 while the extension 260 is pivotably biased against the articulating base 170 . Thus, no portion of the saw blade (not shown) is exposed to a user.
With the portable saw system 100 in this configuration, the operator determines the type of cut that is needed on a work-piece. In the event that the operator desires to perform a rip cut on a work-piece, the fence 106 is positioned on the base 102 with the locking mechanism 162 positioned over the locking member 124 and the handle 168 in a raised position as shown in FIG. 4 . Once the fence 106 is positioned along the locking member 124 at a location corresponding the to desired width of the work-piece, the handle 168 is moved in a downwardly direction from the position shown in FIG. 4 to the position shown in FIG. 16 , thereby moving the movable dog 164 against the locking member 124 so as to clamp the locking member 124 between the movable dog 164 and the fixed dog 166 . Thus, the side 169 of the shaft 154 defines a guide axis perpendicular to the axis 126 associated with the locking member 124 (see FIG. 3 ). In alternative embodiments, a handle may move a member located between two dogs to clamp the fence.
Next, the articulating support structure 104 is unlocked from the base 102 by movement of the miter lock arm 212 in the direction of the arrow 300 in FIG. 16 . The articulating support structure 104 is then pivoted about the pivot axis 302 defined by the pivot 180 in the direction of the arrow 304 until the articulating support structure 104 abuts the wall 140 . The articulating support structure 104 is then locked into position by movement of the miter lock arm 212 in the direction opposite the arrow 300 in FIG. 16 , thereby pulling the enlarged head 194 against the base 102 .
Positioning the articulating support structure 104 against the wall 140 places the circular arms 188 and 190 in a position parallel to the shaft 154 . Additionally, the plunger 196 is aligned with the locking bore 150 . The plunger 196 is then extended into the locking bore 150 by depressing the spring loaded rip lock button 210 . As the plunger 196 extends into the locking bore 150 , the rip lock release button 214 automatically engages the plunger 196 locking the plunger 196 within the locking bore 150 .
Depression of the rip lock button 210 further causes the female A/B switch member 216 to be configured to accept the male A/B switch member 242 . The power tool 108 may then be slid along the circular arms 188 and 190 until the male A/B switch member 242 enters the female A/B switch member 216 . To ensure the power tool 108 is not accidentally energized during this movement, the lockout switch 236 may be depressed. Depression of the lockout switch 236 locks the momentary power switch 234 into contact with the electrically isolated terminal 280 (see FIG. 14 ).
Continuing with FIG. 14 , as the male A/B switch member 242 enters the female A/B switch member 216 , the A/B switch 272 , which is biased toward the terminal 286 , is forced away from the terminal 286 and into contact with the terminal 292 . Accordingly, the motor 294 may be energized by movement of the toggle switch 202 into contact with the terminal 276 .
Returning to FIG. 16 , prior to energizing the portable tool 108 , the riving knife 256 and the kick-back pawls 252 and 254 are positioned and secured using the riving knife locking knob 258 . The portable saw system 100 may then be energized by positioning the toggle switch 202 into contact with the terminal 276 and a work-piece fed onto the upper table portion 110 along the fence 104 in the direction of the arrow 306 . As the work-piece engages the extension 260 , the extension 260 is pivoted upwardly away from the articulating base 170 exposing the work-piece to the saw blade (not shown). As the work-piece passes by the saw blade (not shown), the riving knife 256 spreads the cut portions of the work-piece to prevent binding of the saw blade (not shown) by the work-piece.
Additionally, the work-piece is positioned underneath the kick-back pawls 252 and 254 as the work-piece passes the saw blade. Accordingly, in the event that the work-piece is forced away from the articulating base 170 , the work-piece would contact the kick-back pawls 252 and 254 . This would generate a torque on the power tool 108 . The power tool 108 , however, is prevented from rotation away from the articulating base 170 by the spacing of the circular arms 188 and 190 . Accordingly kick-back of the work-piece is prevented as is undesired movement of the power tool 108 away from the articulating base 170 .
To switch from rip cutting mode to a miter cutting mode after the saw is de-energized, the fence 106 is removed by moving the handle 168 in an upwardly direction from the position shown in FIG. 16 to the position shown in FIG. 4 . This moves the movable dog 164 away from the locking member 124 , allowing the fence 106 to be lifted off of the base 102 .
Next, the fence 106 is positioned on the base 102 with the locking mechanism 162 positioned over the locking member 118 . Once the fence 106 is positioned on the locking member 118 , the handle 168 is moved in a downwardly direction from the position shown in FIG. 4 to the position shown in FIG. 17 thereby moving the movable dog 164 against the locking member 118 so as to clamp the locking member 118 between the movable dog 164 and the fixed dog 166 . Thus, the side 167 of the shaft 154 defines a guide axis perpendicular to the axis 120 associated with the locking member 118 (see FIG. 3 ).
Next, the articulating support structure 104 is unlocked from the base 102 by sliding the power tool 108 along the circular arms 188 and 190 away from the locking pillar 184 until the male A/B switch member 242 exits the female A/B switch member 216 . To ensure the power tool 108 is not accidentally energized during this movement, the lockout switch 236 may be depressed. Depression of the lockout switch 236 locks the momentary power switch 234 into contact with the electrically isolated terminal 280 (see FIG. 14 ).
Continuing with FIG. 14 , as the male A/B switch member 242 exits the female A/B switch member 216 , pressure from the female A/B switch member 216 is removed from the A/B switch 272 . Thus, because the A/B switch 272 is biased toward the terminal 286 , the A/B switch 272 is forced away from the terminal 292 and into contact with the terminal 286 . Accordingly, the motor 294 may only be energized by movement of the toggle switch 202 into contact with the terminal 274 and movement of the momentary power switch 234 into contact with the terminal 282 .
Movement of the male A/B switch member 242 out from the female A/B switch member 216 further allows the plunger 196 to be withdrawn. This is accomplished by depressing the rip lock release button 214 which releases the rip lock button 210 . With the rip lock release button 214 depressed, a spring (not shown) biases the rip lock button 210 in an upwardly direction, thereby withdrawing the plunger 196 from the locking bore 150 . Movement of the plunger 196 out of the locking bore 150 causes the female A/B switch member 216 to be configured to not accept the male A/B switch member 242 .
In the event that a ninety degree miter cut is desired, the articulating support structure 104 need not be repositioned. If a different angle is desired, the articulating support structure 104 is positioned to the desired angle by swinging the miter lock arm 212 in the direction of the arrow 300 in FIG. 16 . This moves the enlarged head 194 away from the base 102 . The articulating support structure 104 is then pivoted about the pivot axis 302 defined by the pivot 180 in the direction of the arrow 306 until the articulating support structure 104 is at the desired angle. The graduated angle indicator 138 may be used to assist in positioning the articulating support structure 104 .
In this embodiment, when the articulating support structure 104 is positioned with the extension 172 fully positioned within the recessed portion 132 , a 45 degree miter cut may be executed on a work-piece. Thus, the articulating support structure 104 can be positioned to provide a miter cut at any desired angle between 45 degrees and 90 degrees. Additionally, because the portable saw system 100 is configured to align a saw blade held by the power tool 108 with the blade slot 178 , the cutting axis of the power tool 108 is aligned with the pivot 180 throughout the range of motion of the articulating support structure 104 .
Once the articulating support structure 104 is in the desired position, the miter lock arm 212 is pivoted in the direction opposite the arrow 300 in FIG. 16 thereby pulling the enlarged head 194 against the base 102 to lock articulating support structure 104 at the desired position.
Prior to performing a miter cut, the riving knife 256 and the kick-back pawls 252 and 254 are moved away from the articulating base 170 and secured using the riving knife locking knob 258 . Additionally, a hold down clamp may be attached to the blade guard 224 using the connection member 250 . After setting the height of the hold down clamp as desired, a work-piece is positioned on portable saw system 100 . Specifically, the work-piece is positioned against the shaft 154 of the fence 106 and upon the top of the articulating base 170 . Depending upon the particular cut and work-piece, the work-piece may also extend onto the upper table portion 110 . To facilitate placement of a work-piece across both the articulating base 170 and the upper table portion 110 , the height of the articulating base 170 is substantially the same as the height of the wall 140 .
The portable saw system 100 may then be energized by positioning the toggle switch 202 into contact with the terminal 274 and depressing the momentary power switch 234 thereby placing the momentary power switch 234 into contact with the terminal 282 . With the power tool 108 energized, the operator slides the power tool 108 along the circular arms 188 and 190 toward the fence 106 .
As the power tool 108 moves toward the fence 106 , the coiled power cord 204 is gathered into the power cord receptacle 200 to ensure the power cord 204 does not contact the work piece or the power tool 108 . Additionally, as the extension 260 engages the work-piece, the extension 260 is pivoted upwardly away from the articulating base 170 exposing the work-piece to the saw blade (not shown).
As discussed above, the cutting axis defined by the power tool 108 is aligned with the pivot 180 . In order to provide a consistent cut location on a work-piece with respect to the base 102 , the pivot opening 146 is positioned such that the axis 302 intersects the guide axis defined by the fence 106 when the fence 106 is locked to the locking member 118 . Accordingly, the saw blade (not shown) will cross the guide axis at the same location regardless of the miter angle. So as to allow the entire width of a work-piece to be cut, the blade cutout 160 is positioned and shaped to allow the saw blade to cross the guide axis defined by the side 167 .
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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A laminate flooring saw system which can be used for both rip cuts and miter cuts in one embodiment includes a first power switch proximate the saw and movable with the saw along a support arm;
a second power switch that is not movable with the saw along the support arm; and a third switch movable between a first position wherein application of energy to the saw is dependent upon the position of the second power switch and independent of the position of the first power switch and a second position wherein application of energy to the saw is dependent upon the position of both the first power switch and the second power switch.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to electronic amplifiers, and more specifically to employing multi-chip Doherty amplifiers with integrated power detection to control amplifier biasing.
BACKGROUND OF THE INVENTION
[0002] In electronics, there is an ongoing need to improve the efficiency and bandwidth of amplifier circuits. One method for improving the efficiency of an amplifier was invented in 1934 by William H. Doherty. A typical Doherty amplifier is shown in FIG. 1 and has a class-AB main amplifying stage 110 in parallel with a class-C auxiliary amplifier stage 120 . The Doherty amplifier receives an input signal from an off-chip source that controls the biasing provided to the amplifier stages using a biasing control circuit. An input signal is split evenly to drive the two amplifiers, and a combining network 102 sums output signals from the main and auxiliary stages and corrects for phase differences between them. During periods of lower signal power levels, the main stage efficiently amplifies the input signal and the auxiliary stage remains off. In this mode, the main amplifier dynamic load impedance is about two times higher than the optimum power match. During higher power signal peaks, main stage 110 approaches compression but remains operating while auxiliary stage 120 also turns on and transforms the dynamic load of both amplifiers to their optimum power match. This increases the overall efficiency dynamic range (which is the input power range over which efficiency remains high) by about 6 dB.
[0003] In a typical Doherty amplifier assembly, the class-AB main amplifying stage 110 and the class-C auxiliary amplifier stage 120 are manufactured on integrated circuits having different operating parameters. In a prior art embodiment, an off-chip power detector and bias control circuit 130 is used to provide bias for the class-AB main amplifier 110 and the class-C auxiliary amplifier 120 . The same input biasing voltage is provided to each biasing control circuit. In turn, the individual integrated circuits are designed to produce the desired amplification of the various amplification stages 110 , 120 using this common biasing voltage. However, the use of an off-chip detector and control solution adds complexity to the design. Thus, a need exists for a Doherty amplifier design that utilizes the same integrated power detection and bias control circuits in both the main amplifying stage and the auxiliary amplifier stage. Furthermore, a need exists for the main amplifier and the auxiliary amplifier to be created using the same MMIC design.
SUMMARY OF THE INVENTION
[0004] In accordance with an exemplary embodiment of the present invention, a Doherty amplifier is provided for applications in radio frequency (RF), microwave, and other electronic systems. In an exemplary embodiment, a Doherty amplifier comprises a first MMIC having a first power detector, and a second MMIC having a second power detector. The first MMIC and the second MMIC are structurally identical. Furthermore, the first MMIC is configured as a carrier amplifier and the second MMIC is configured as a peaking amplifier. In the exemplary embodiment, an amplifier control bias of the carrier amplifier is a function of the power detected by the first power detector and an amplifier control bias of the peaking amplifier is a function of the power detected by the second power detector. In accordance with the exemplary embodiment, an integrated power detection bias control circuit is adaptable to provide bias for a class-AB main amplifier or a class-C auxiliary amplifier. The ability to assemble a Doherty amplifier using a single MMIC product results in a simple and less expensive manufacturing process. Furthermore, using the same MMIC design for both the class-AB main amplifier and the class-C auxiliary amplifier saves design cost and production cost.
[0005] Furthermore, an exemplary N-way multichip Doherty amplifier has N physically identical separate parallel amplifier paths, where each path has an amplifier MMIC, an RF power detector, a splitter connected to each MMIC to provide input signals and a combiner connected to the outputs of each MMIC. An exemplary method of controlling the Doherty amplifier includes detecting, with a first RF power detector, the power in an RF input signal in a first amplifier path of a first amplifier MMIC, providing a signal representing the detected power to an amplifier MMIC gate bias control of the first amplifier MMIC, and biasing the first amplifier MMIC based on at least the detected power provided to the amplifier MMIC gate bias control. The exemplary method also includes detecting, with a second RF power detector, the power in the RF input signal in a second amplifier path of a second amplifier MMIC, providing a signal representing the detected power to an amplifier MMIC gate bias control of the second amplifier MMIC, and biasing the second amplifier MMIC based on at least the detected power provided to the amplifier MMIC gate bias control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. In the drawings, like reference numerals designate like parts throughout the different views, wherein:
[0007] FIG. 1 is a schematic representation of a conventional Doherty amplifier;
[0008] FIG. 2 is a block diagram of one exemplary embodiment of a multi-chip Doherty amplifier in accordance with an exemplary embodiment of the invention;
[0009] FIGS. 3A and 3B illustrate a block diagram of an exemplary embodiment of multi-chip Doherty amplifier; and
[0010] FIG. 4 is another block diagram of an exemplary embodiment of a multi-chip Doherty amplifier in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] While exemplary embodiments are described herein in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical material, electrical, and mechanical changes may be made without departing from the spirit and scope of the invention. Thus, the following detailed description is presented for purposes of illustration only.
[0012] A typical Doherty amplifier includes multiple amplifier paths. The basic configuration has only two paths, a peaking amplifier path and a carrier amplifier path. In accordance with an exemplary embodiment and with reference to FIG. 2 , a multi-chip Doherty amplifier 200 comprises a peaking amplifier MMIC 210 and a carrier amplifier MMIC 220 . MMIC 210 and MMIC 220 each receive an input signal from an off-chip 90° splitter 201 . Each MMIC 210 , 220 also transmits an output signal to an off-chip Doherty combining network 202 . Furthermore, in an exemplary embodiment, peaking amplifier MMIC 210 comprises at least one amplifier 211 , an amplifier bias control circuit 212 , and a power detector 213 . Similarly, in an exemplary embodiment, carrier amplifier MMIC 220 comprises at least one amplifier 221 , an amplifier bias control circuit 222 , and a power detector 223 .
[0013] In an exemplary embodiment, amplifier bias control circuits 212 , 222 generate a desired “amplifier bias versus RF power” function. The amplifier bias control circuits 212 , 222 are configured to individually receive a signal (referred to as an input) from power detectors 213 , 223 , respectively. For example, the input may be a DC input. The input controls the amount of bias current supplied by amplifier bias control circuits 212 , 222 to the at least one amplifiers 211 , 221 . In an exemplary embodiment, the bias voltage is supplied to the gate of the amplifiers and controls the amplification levels. Furthermore, in an exemplary embodiment, the bias current of carrier amplifier MMIC 220 remains substantially constant with RF input power. In another exemplary embodiment, the bias current of peaking amplifier MMIC 210 increases with RF input power. In addition, amplifier bias control circuits 212 , 222 are powered from an outside source. The outside source is separate from the input provided by power detectors 213 , 223 . For example, FIG. 2 shows amplifier bias control circuits 212 , 222 being powered by VDD, though any other suitable input power may be used.
[0014] In accordance with an exemplary embodiment, the bias of amplifier bias control circuits 212 , 222 are a function of the RF input power. The RF input power may be detected by an RF power detector, for example, power detectors 213 , 223 . In an exemplary embodiment, the RF power detector is integrated on each of said MMICs 210 , 220 . In another exemplary embodiment, the RF power detector is located off-chip and sends an amplifier bias control signal to the corresponding MMIC. In accordance with an exemplary embodiment, the RF power detector generates the amplifier bias control signal based on the level of power drawn through the corresponding MMIC. The amplifier bias control signal is used to bias amplifier bias control circuits 212 , 222 . Furthermore, the amplifier bias control signal is influenced by the biasing of the RF power detector, which controls the sensitivity of the power detector.
[0015] In an exemplary embodiment, one or more adaptive RF power detectors is configured to provide different bias functions to each amplifier path in an N-way multi-chip Doherty amplifier, where identical MMICs are used in the Doherty amplifier. Accordingly, in an exemplary embodiment, power detectors 213 , 223 are adaptive by individually biasing the power detectors at different voltages. As such, power detector 213 may have different biasing than power detector 223 .
[0016] In an exemplary embodiment, the bias of the power detector is set according to the specific amplifier path. The DC output of the power detector is then fed to the bias control circuit of the Doherty amplifier, and used to generate a desired “amplifier bias vs. RF power” function. The “amplifier bias vs. RF input” function desired for carrier amplifier MMIC 220 can be realized by making power detector 223 on carrier amplifier MMIC 220 insensitive to RF input power. Biasing the power detector at a negative voltage (reverse-biasing) results in decreased sensitivity to the RF power, or results in the power detector not responding to a range of RF input power. Thus, in an exemplary embodiment, power detector 223 on MMIC 220 is reverse biased. For example, power detector 223 may be reverse-biased at −3.3 volts. In another example, power detector 223 may be reverse-biased at a voltage in the range of −1 to −5 volts. Furthermore, power detector 223 may be reverse-biased at any suitable negative voltage.
[0017] The “amplifier bias vs. RF input” function desired for peaking amplifier MMIC 210 can be realized by making power detector 213 on peaking amplifier MMIC 210 sensitive to RF input power. Biasing the power detector at a positive voltage (forward-biasing) results in increased sensitivity to the RF power. Thus, in an exemplary embodiment, power detector 213 on MMIC 210 is forward biased. For example, one power detector may be forward-biased at 0.5 volts. In another example, power detector 213 may be forward-biased at a voltage in the range of 0.1 to 5 volts. Furthermore, power detector 223 may be forward-biased at any suitable positive voltage.
[0018] In one exemplary embodiment and with reference to FIG. 3A , a MMIC 310 of a Doherty amplifier includes multiple contact pads 330 (bond pads). The contact pads 330 are the input point for the external bias voltage (VDD) being fed to MMIC 310 . In an exemplary embodiment, different bond pads 330 are configured to provide different wire-bondable tap points within a voltage divider circuit. In an exemplary embodiment and as illustrated by FIG. 3A , bond pads 330 may be divided into two groups. A first group of bond pads 330 are designed for positive voltage biasing and a second group of bond pads 330 are designed for negative voltage biasing. The different bond pads 330 allow the proper detector bias to be achieved on chip. In accordance with an exemplary embodiment, multiple contact pads 330 on MMIC 310 allow for flexibility to adjust for process variation in the MMIC. In other words, multiple contact pads 330 may facilitate adjusting for manufacturing tolerances in MMIC 310 . Furthermore, in an exemplary embodiment, the biasing of the power detectors is configured as a function of temperature for additional biasing control.
[0019] In another exemplary embodiment, multiple contact pads 330 provide a substantial difference in voltage biasing. For example, connecting 5 volts to a first contact pad may result in biasing a power detector at 0.5 volts. In contrast, connecting the same 5 volts to a second contact pad may result in biasing the power detector at less than 0.5 volts. In this exemplary embodiment, a common external power supply (VDD) supplies different biasing voltages to a power detector based on alternate contact pad connections and voltage division circuitry. In an exemplary negative voltage embodiment, a negative voltage is connected to a contact pad in order to bias a power detector at a negative voltage. In yet another exemplary embodiment, the sign of the bias voltage to the power detector is not limited to being the same sign as the supplied voltage. In other words, a positive VDD may be supplied to a contact pad and result in a negative bias voltage to the power detector. Similarly, a negative VDD may be supplied to a contact pad and result in a positive bias voltage to the power detector. Additionally, in an exemplary embodiment, the connection to a contact pad is made during assembly. In another exemplary embodiment, the connection to a contact pad is made after assembly in order to facilitate at least one of tuning and error adjustment.
[0020] In accordance with an exemplary embodiment and with reference to FIG. 3B , MMIC 310 of a Doherty amplifier further comprises a first bias voltage connection 398 and a second bias voltage connection 399 . The first and second bias voltage connections 398 , 399 are connected to contact pads 330 and supply the external bias voltage (VDD) being fed to MMIC 310 . In the exemplary embodiment, VDD is supplied through either first bias voltage connection 398 or second bias voltage connection 399 . A switch may be used to change between the two connections. Supplying the external bias voltage to different contact pads 330 results in different biasing of the power detector.
[0021] In one embodiment, this switching may be used to adjust the operating of MMIC 310 of the Doherty amplifier. For example, switching between contact pads 330 facilitates error correction that may occur during operation. In another exemplary embodiment, more than two bias voltage connections may be present on MMIC 310 , allowing for additional adjustment. Furthermore, in an exemplary embodiment, a switch used to change between the bias voltage connections operates at a switching rate that is at least 2 times faster than the modulation bandwidth of the Doherty Amplifier. A faster switching rate allows the change between first bias voltage connection 398 and second bias voltage connection 399 without missing a cycle of RF input.
[0022] Moreover, a Doherty amplifier with N amplifier paths is generally referred to as an N-way Doherty amplifier. In an exemplary embodiment and with reference to FIG. 4 , a Doherty amplifier comprises multiple amplifier paths. In one embodiment, each path of an N-way Doherty amplifier is a separate MMIC. In an exemplary embodiment, each separate MMIC of the amplifier paths is the same, or substantially equivalent, MMIC type as the other MMICs of the N-way Doherty amplifier. An advantage of the implementing the same MMIC type in all amplifier paths is the increased convenience and cost effectiveness during manufacturing.
[0023] With continued reference to FIG. 4 , in an exemplary embodiment, the N amplifier paths are biased differently. For example, the first MMIC may be biased as a carrier amplifier. The second MMIC may be biased as an initial peaking amplifier. The Nth MMIC may be biased as a higher level peaking amplifier. In other words, the Nth MMIC amplifies the signal in response to the signal exceeding the amplification level of the first and second MMICs.
[0024] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. Exemplary embodiments of the invention have been disclosed in an illustrative style. Accordingly, the terminology employed throughout should be read in an exemplary rather than a limiting manner. As used herein, the terms “includes,” “including,” “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, no element described herein is required for the practice of the invention unless expressly described as “essential” or “critical.” Although minor modifications to the teachings herein will occur to those well versed in the art, it shall be understood that what is intended to be circumscribed within the scope of the patent warranted hereon are all such embodiments that reasonably fall within the scope of the advancement to the art hereby contributed, and that that scope shall not be restricted, except in light of the appended claims and their equivalents.
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In accordance with an exemplary embodiment of the present invention, a Doherty amplifier is provided for applications in radio frequency, microwave, and other electronic systems. An exemplary Doherty amplifier comprises a first MMIC having a first power detector, and a second MMIC having a second power detector. The first MMIC and the second MMIC are structurally identical. Furthermore, the first MMIC is configured as a carrier amplifier and the second MMIC is configured as a peaking amplifier. In the exemplary embodiment, an amplifier control bias of the carrier amplifier is a function of the power detected by the first power detector and an amplifier control bias of the peaking amplifier is a function of the power detected by the second power detector. The ability to assemble a Doherty amplifier using a single MMIC product results in a simple and less expensive manufacturing process.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to shiftable change speed shifting mechanisms comprising selectively, axially movable gears and, in particular, relates to multiple countershaft transmissions utilizing resiliently yieldable shifting mechanism comprising selectively, axially movable main shaft gears having clutch teeth associated therewith and axially movable, resiliently biased clutch collars splined to the main shaft for selectively rotationally fixing said main shaft gears to said main shaft, said clutch collars having clutch teeth associated therewith for engaging the clutch teeth associated with said main shaft gears, wherein the spline teeth of one of the main shaft or clutch collar are of a constantly variable thickness to prevent or minimize undesired disengagement of an engaged mainshaft gear and clutch collar.
2. Description of the Prior Art
Change speed transmissions utilizing resiliently yieldable shifting mechanisms incorporating selectively, axially movable gears and, in particular, multiple countershaft, floating main shaft transmissions utilizing resiliently yieldable shifting mechanisms, are known in the prior art and may be seen by reference to U.S. Pat. Nos. 3,799,002; 3,910,131; 3,921,469; 3,924,484; and 3,983,979, all of which are assigned to the assignee of this invention and all of which are hereby incorporated by reference.
Briefly, the above mentioned multiple countershaft, floating main shaft transmissions utilizing resiliently yieldable shifting mechanisms comprise selectively, axially movable main shaft gears and axially movable clutch collars splined to the main shaft which are resiliently biased toward said main shaft gears and which are positively stopped from moving into engagement therewith until said main shaft gears are axially moved toward said clutch collars. The main shaft gears have clutch teeth associated therewith, preferably integral internal clutch teeth, and the clutch collars have integral external clutch teeth which are adapted to engage the clutch teeth associated with said main shaft gears. In the preferred embodiments of the above mentioned transmissions, various types of blockers are utilized to prevent engagement of the clutch teeth until the main shaft gear selected to be rotationally fixed to the main shaft is rotating at a synchronous speed with the main shaft. The main shaft gears are selectively, axially movable by shift fork mechanisms as is well known in the prior art and the shift fork mechanisms were manipulated by either a linkage mechanism or by a pressure fluid motor, such as an air cylinder, as is also well-known in the prior art.
While the above mentioned transmissions have proven to be highly desirable, especially for substantially simplifying shifting of the transmissions, in certain circumstances, especially in those transmissions utilizing air motor manipulated shift forks, the clutch teeth associated with certain engaged main shaft gears occasionally tended to undesirably disengage from the clutch teeth associated with the engaged clutch collar. This problem, which is sometimes referred to as "kick out", most often occurred during severe usage of the transmission. Such undesirable disengagement, or "kick out", while not completely understood, is believed to be caused by the engaged, selectively axially movable main shaft gear wobbling in respect to the axis of rotation of the main shaft which is believed to cause the main shaft gear to move axially against the shift fork and the bias of the shift cylinder until the clutch teeth associated therewith became disengaged from the clutch teeth associated with the clutch collar. The problem of undesirable disengagement, although not fully understood, is most often associated with those types of multiple countershaft transmissions wherein the main shaft gear is selectively axially moved toward engagement with a clutch collar, rather than with those types of transmissions wherein the main shaft gear is axially fixed with respect to the main shaft.
SUMMARY OF THE INVENTION
In accordance with the present invention, the prior art transmissions have been improved to the extent that a shiftable change speed transmission utilizing resiliently yieldable shifting mechanisms comprising a selectively, axially movable main shaft gear and an axially movable, resiliently biased clutch collar splined to the main shaft is provided which greatly minimizes or eliminates the problem of undesired disengagement during operating conditions. The above is accomplished by utilizing a clutch collar which is splined to the main shaft wherein the splines, also called "spline teeth", of the clutch collar or the main shaft are of a substantially constantly variable circumferential thickness. The constantly variable thickness spline teeth of the clutch collar or main shaft are arranged such that the spline teeth are thickest at the axial end of the clutch collar closest the main shaft gear with which it is associated when the clutch collar is in the axially non-displaced position. In the preferred embodiment, for manufacturing reasons, the clutch collar is the member carrying the constantly variable thickness spline teeth, thus the spline teeth of the clutch collar are of a greater circumferential thickness at the axial end thereof closest the main shaft gear with which the clutch collar is associated. The sides of the constantly variable spline teeth define an angle with respect to a line parallel to the axis of rotation of the clutch collar in the range of about 1/4° to 2° (preferably about 1/2°).
Accordingly, it is an object of the present invention to provide a new and improved change speed transmission utilizing shifting mechanisms comprising selectively axially movable gears.
Another object of the present invention is to provide an improved change speed transmission having resiliently yieldable shifting mechanisms comprising selectively, axially movable main shaft gears having clutch teeth associated therewith and axially movable clutch collars splined to the main shaft and biased toward the main shaft gear, said clutch collars positively stopped from engaging the main shaft gears in the disengaged position thereof, the splines of the clutch collar or the main shaft being of a constantly variable circumferential thickness to prevent or minimize undesired disengagement of an engaged main shaft and clutch collar.
These objects and advantages of the present invention will become apparent from a reading of the detailed description of the preferred embodiment taken in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of one embodiment of the improved transmission of the present invention as taken substantially along the lines I--I in FIG. 5.
FIG. 2 is a cross sectional view of the improved transmission of FIG. 1 taken substantially along the lines II--II in FIG. 5.
FIG. 3 is an enlarged fragmentary view of the improved resilient clutch structure of the embodiment of FIG. 1 according to the present invention.
FIG. 4 is a sectional view of the embodiment of FIG. 1 as taken substantially along the lines IV--IV in FIG. 5.
FIG. 5 is a sectional, elevational view taken along the lines V--V in FIG. 1.
FIG. 6 is a cross sectional view similar to FIG. 2 of an alternate embodiment of the present invention.
FIG. 7 is a portion of FIG. 6 on an enlarged scale.
FIG. 8 is an elevational view of a slidable clutch component and its associated blocker as viewed from the left in FIG. 6.
FIG. 9 is a sectional view taken on the line IX--IX in FIG. 4.
FIG. 10 shows the clutch collar fragmentarily in an unwrapped condition taken along the lines X--X in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Certain terminology will be used in the following description for convenience and reference only and will not be limiting. The words "upwardly", "downwardly", "rightwardly", and "leftwardly" will designate directions in the drawings to which reference is made. The words "forward" and "rearward" will refer respectively to the front and rear ends of the improved transmission as same is conventionally mounted in the vehicle, being respectively the left and right sides of the transmission as is illustrated in FIGS. 1 and 2. The words "inwardly" and "outwardly" will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof, and words of a similar input.
The present invention relates to a spline structure for interconnecting clutch collars to main shafts in transmissions of the type utilizing selectively axially movable mainshaft gears. For purposes of illustration, the transmissions illustrated are of the type having resiliently yieldable shifting mechnisms, it being understood the invention is equally applicable to transmissions wherein the clutch collars are axially fixed with respect to the mainshaft. Further, for purposes of simplifying illustration of the present invention, the resiliently yieldable shifting mechanisms illustrated in FIGS. 1, 2, 3, 4, 8 and 9 are of the type not utilizing blockers, it being understood the invention is equally applicable to resiliently yieldable shifting mechanisms utilizing blockers and that in the preferred embodiment such resiliently yieldable shifting mechanisms do utilize blockers.
Change speed transmissions of the type illustrated in the drawings having resiliently yieldable shifting mechanisms wherein the mainshaft gears are selectively axially movable and the axially movable clutch collars are splined to the mainshaft and are resiliently biased toward the mainshaft gear associated therewith are illustrated in U.S. Pat. No. 3,799,002, assigned to the assignee of this invention and hereby incorporated by reference. Improved blocker constructions for such transmissions are illustrated in U.S. Pat. Nos. 3,921,469; 3,924,484; and 3,983,979, which are also assigned to the assignee of this invention and hereby incorporated by reference.
Referring to FIGS. 1, 2, 3, 4, 9 and 10, there is illustrated a transmission 11 having both a main transmission section 12 and a range or auxiliary transmission section 13, each of which has a plurality of selectable ratios. The main and range sections are both suitably enclosed by a conventional housing 14.
The transmission 11 specifically includes an input shaft 16 supported adjacent its rearward end by a bearing 17 and provided with an input gear 18 nonrotatably connected thereto, as by splines. The input gear 18 simultaneously drives a plurality of countershafts at equal speeds. In the illustrated embodiment, the transmission is provided with two countershafts 21 and 22 disposed on diametrically opposite sides of the main shaft 23, which main shaft is coaxially aligned with the input shaft 16 and is provided with a pilot portion 24 on its forward end rotatably received within and supported by the rearward end of the input shaft 16.
Each of the countershafts 21 and 22 is provided with an identical grouping of countershaft gears 25, 26, 27, 28 and 29 thereon, which groupings form pairs of gears, such as the pair of gears 26, of identical size and number of teeth and disposed on diametrically opposite sides of the main shaft 23.
A plurality of main shaft drive gears 31, 32, 33 and 34 encircle the main shaft and are selectively clutchable thereto one at a time by yieldable clutch mechanisms, as described in greater detail hereinafter.
The main shaft gears 31, 32 and 33 encircle the main shaft 23, are in continuous meshing engagement with, and are floatingly supported by, the diametrically opposed pairs of countershaft gears 26, 27 and 28, respectively, which mounting means and the special advantages resulting therefrom are explained in greater detail in U.S. Pat. Nos. 3,105,393, and 3,335,616. The main shaft gear 34 is the reverse gear and is in continuous meshing engagement with the pair of countershaft gears 29 by means of conventional intermediate gears (not shown). The forwardmost countershaft gears 25 are continually meshed with and driven by the input gear 18 for causing simultaneous rotation of the countershafts 21 and 22 whenever the input shaft 16 is rotatably driven.
As illustrated in FIG. 2, the main shaft gears 31 and 32 are axially interconnected to form a gear pair and are connected to a conventional shift fork 36, the position of the shift fork 36 being controlled in a conventional manner by means of a shift lever 37. The main shaft gear pair 31-32 is thus shiftable axially relative to the main shaft 23 in response to axial shifting of the fork 36 by the lever 37. However, the gears 31 and 32 are independently rotatable relative to one another. In a similar manner, the main shaft gears 33 and 34 are also axially interconnected so as to be axially shiftable as a pair by means of the shift fork 38, which shift fork is also controlled by means of the shift lever 37. The main shaft gear pair 33-34 is likewise axially movable relative to the main shaft 23. It is understood that the shift forks may be manipulated b pressure fluid motors as well as by shift levers.
The input gear 18 is also interconnected to a conventional shift fork 39, which shift fork is similarly controlled by the shift lever 37 for permitting input gear 18 to be shifted axially for selectively permitting direct driving engagement between the input shaft 16 and the main shaft 23.
The yieldable clutch structure, as illustrated in detail in FIG. 3, is generally designated 41 and includes an annular clutch collar 42 encircling the main shaft 23. The clutch collar 42 is provided with internal splines 43 which are disposed within corresponding external splines 44 provided on the main shaft 23 for interconnecting the clutch collar 42 to the main shaft 23 for rotation therewith. However, the cooperating splines 43 and 44 permit the clutch collar 42 to freely slide axially relative to the shaft 23. A stop ring 46 is seated within a suitable groove formed on the external periphery of the shaft 23 and is disposed for contacting the clutch collar 42 and limiting the axial movement thereof. The collar 42 is normally resiliently urged by means of a spring 47 into abutting engagement with the stop ring 46.
The clutch collar 42 is provided with external teeth 48 thereon which are adapted to meshingly engage the internal teeth 49 provided on one of the main shaft gears, such as the gear 33. The teeth 48 on the clutch collar 42 are tapered, as at 51, and in a similar manner the leading edge of the teeth 49 on the main shaft gear 33 are similarly tapered as at 52. The confronting tapered conical surfaces 51 and 52 each extend at an angle of preferably between 30 and 40 degrees relative to the longitudinal axis of the main shaft 23. The exact degree of taper, and the advantages thereof, are explained in detail in U.S. Pat. No. 3,265,173. The other end of the spring 47 resiliently acts against a further clutch collar 53, which collar is identical to the collar 42 but is disposed so that it has the tapered leading end of its teeth facing in the opposite direction. The clutch collar 53 has external teeth 54 which are adapted to meshingly engage the internal teeth 56 provided on the main shaft gear 32, the leading edges of the teeth 54 and 56 each being tapered in a manner similar to the tapered surfaces 51 and 52 as explained in detail above. The clutch collar 53 is also provided with internal splines 57 for nonrotatably but axially slidably engaging the external splines 44 on main shaft 23. The clutch collar 53 is resiliently urged by the spring 47 into a position whereby it normally abuttingly contacts a further stop ring 58. The structural details of mainshaft splines 44 and the clutch collar splines such as 57 comprise the improvement of the illustrated transmission and are described in detail below.
A further resilient clutch assembly 41A is disposed concentrically to the main shaft 23 and positioned between the main shaft gear 31 and the input gear 18. The yieldable clutch assembly 41A is identical to the clutch assembly 41 and is disposed for mshing engagement with the internal teeth of either of the main shaft gear 31 or the input gear 18.
The main shaft 23 is additionally provided with a further clutch collar 59 concentrically and nonrotatably mounted thereon, which clutch collar 59 is identical to the clutch collar 42 described above. However, the clutch collar 59 is axially confined relative to the mainshaft 23 by stop rings 61 and 62 disposed on the opposite axial sides thereof. The clutch collar 59 is disposed for meshing engagement with the internal teeth of the main shaft gear 34 when said gear 34 is shifted rightwardly from the position illustrated in FIG. 2. The clutch collar 59 is not resiliently loaded or biased as is true of the clutch assemblies 41 or 41A since the clutch collar 59 is utilized only when the transmission is driving in reverse, and thus the resilient loading of the clutch collar is not necessary. However, a spring could obviously be provided for resiliently loading the clutch collar 59 if so desired.
Considering now the range section 13, same includes a plurality of countershafts 66 and 67 (FIG. 5) each having an identical grouping of countershaft gears 68 and 69 (FIG. 4) thereon. The first pair of countershaft gears 68 are disposed diametrically opposite and in continuous meshing engagement with a main shaft gear 71, which main shaft gear is floatingly supported by the pair of countershaft gears 68 for substantially concentrically encircling the main shaft 23. A further mainshaft gear 72 is also floatingly and substantially concentrically supported relative to the main shaft 23 by the other pair of countershaft gears 69. The pair of main shaft gears 71 and 72 are axially interconnected and axially movable relative to the main shaft 23 by a further shift fork 73 which shift fork is connected to and movable by any automatically controllable power means, such as a piston structure 76. The piston structure 76 is shiftable in a conventional manner, such as by means of a manually actuated, preferably preselectable, range shift button or lever provided in the vehicle occupant compartment, which in turn controls a valve (not shown) for supplying pressure fluid to the piston structure.
As illustrated in FIG. 2, the main shaft 23 extends continuously through not only the main transmission section 12, but also through the range transmission section 13. The rearward end of the main shaft 23 is provided with a pilot portion 23A which is rotatably received and supported within the end of the output shaft 77.
The range section main shaft gears 71 and 72 are each individually clutchably engageable with the main shaft 23 by means of a resilient clutch assembly 41B, which assembly is identical to the assembly 41 described above. The assembly 41B includes clutch collars 42B and 53B splined on the main shaft 23 and resiliently urged axially in opposite directions by means of the intermediate spring 47B. The external teeth formed on the clutch collars 42B and 53B are adapted to respectively meshingly engage the internal teeth formed on the main shaft gears 72 and 71, respectively. The internal teeth on the main shaft gear 72 are also disposed in meshing engagement with corresponding external teeth formed on the output shaft 77 as illustrated in FIG. 2.
In FIGS. 6, 7, and 8, the preferred embodiment of transmission 11, in which blockers or blocking rings, such as illustrated member 108, are utilized in connection with the resiliently biased clutch collars to prevent engagement of the clutch units until synchronous rotation of the units is achieved is illustrated.
The general operation of the transmissions of FIGS. 1-5 and of 6-8 is well defined in the above mentioned patents, especially U.S. Pat. No. 3,921,469, and thus will not be discussed further herein.
The spline structure comprising the improvement of the present invention may best be seen by reference to FIGS. 9 and 10.
FIG. 9 is a cross sectional view of the clutch collar 53 and main shaft 23. The clutch collar 53 is mounted to the main shaft 23 for axial movement relative thereto and for rotational movement therewith by means of internal splines, or spline teeth 57, which mate with external splines, or spline teeth 44, on the main shaft 23. In cross-section the axially extending internal spline teeth 57 are defined by a circumferentially extending top land 200 and a pair of generally radially extending sides or flanks 202. The splined teeth 57 are separated by generally circumferentially extending bottom lands 204. At a given radial distance from the axis of rotation, taken on a plane perpendicular to the axis of rotation, the circumferential distance from one side of a splined tooth 57 to the other side of the splined tooth defines the circumferential thickness 206 of the splined tooth at the axial point the plane passes through the axis of rotation.
In the prior art devices, for all axial points along the axial extension of the splines, at a given radius from the axis of rotation, the circumferential thickness of the splined teeth of the main shaft and of the clutch collar was substantially constant. In sharp contrast, the circumferential thickness 206 of the splines 57 of the improved transmission 11 is constantly variable and increases toward the axial end 210 of the clutch collar closest the main shaft gear with which it is associated. That is, the circumferential thickness 206 of the spline teeth 57 for a given radial distance from the axis of rotation is greater at the axial end 210 of the clutch collar 53 closest the main shaft gear with which the clutch collar is associated.
Referring to FIG. 10, which is a fragmentary view in which the substantially constantly increasing circumferential thickness of the spline teeth 57 is shown in an exaggerated manner for illustrative purposes only, it may be seen that the intersection of the sides 202 with the top or bottom lands defines an angle A with respect to a line L parallel to the axis of rotation. The angle A is in the range of about 1/4° to 2° and is preferably about 1/2°.
Applicants have discovered that by providing clutch rings of the type shown wherein the splined teeth are of a substantially constantly increasing circumferential thickness toward the end of the clutch collars closest the main shaft gear with which the clutch collar is associated, the incidence of undesired disengagement of engaged main shaft gears from their associated clutch collars is substantially reduced or eliminated. Although the causes of undesired main shaft gear disengagement and the reason why the present invention substantially reduces same is not fully understood, it is believed that by providing spline teeth on the clutch collars which are circumferentially thicker at the end thereof which is closest the associated main shaft gear, the forces transmitted from the main shaft gear are transmitted through a point contact which tends to eliminate the tendency of the main shaft gear to move axially against the bias of the shift fork and member biasing the shift fork.
Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and combination and arrangement of the parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
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An improved shiftable change speed transmission is provided. The improved transmission is preferably provided with at least one countershaft having countershaft gears thereon disposed in meshing engagement with main shaft gears encircling the transmission main shaft. Gears are selectively axially movable relative to the associated shaft by conventional means for effecting shifting of the transmission. The axially movable gears cooperate with clutch rings which surround and are supported on and for rotation with the associated shaft by splines, preferably the clutch rings also are axially movable relative to the associated shaft and are resiliently urged in a direction toward the respective gear with which same cooperates, whereby shifting of the axially movable gear toward its respective clutch ring causes resilient axial movement of the latter until synchronization is achieved to permit the clutch ring to move axially in response to said resilient urging and engage the main shaft gear. The improvement comprises providing spline teeth on the clutch ring or the associated shaft which are of a substantially constantly varying thickness and are arranged such that, when the clutch rings are in the non-axially displaced position, the circumferential spacing betwen cooperating clutch ring and shaft spline teeth is smaller at the axial end of the clutch ring closest to the gear with which it is associated than at the other end of the clutch ring.
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FIELD OF THE INVENTION
This invention relates to traffic barricades. It relates particularly to molded plastic traffic barricades.
BACKGROUND OF THE INVENTION
Traffic barricades are commonly used to warn vehicular and pedestrian traffic of danger, and block off restricted areas. Barricades made of molded plastic have now been known for some time. Examples are found in the Stehle, et al. U.S. Pat. Nos. 3,880,406 and 3,950,873, the Glass U.S. Pat. Nos. 4,298,186 and 4,624,210. Barricades illustrated in these patents include barricades made with two panel units hinged together so that they can be spread apart for use and collapsed for storage or transport. The individual panel units are one piece, integral, hollow plastic panels, formed by rotational or blow molding. The lower hollow sections may contain ballast.
These and other plastic traffic barricades have proven to be a great improvement over conventional steel and wood barricades. They are rugged, yet cause less damage to vehicles if inadvertently struck. Through the use of ballast in the units, the center of gravity of the barricade is lower than either wood or metal barricades. The result is a barricade less susceptible to being blown over by wind. Other features typically incorporated in such barricades are bright colored reflective horizontal panels, flashing lights or signs, and a structural member near the bottom where a sand bag can be placed if additional ballast is required.
Problems linger with many plastic barricades on the market today, however. Internally ballasted plastic barricades have proven to be marginally acceptable on high speed highways because they are not heavy enough to remain in place when buffeted by vehicle induced drafts. All to frequently, on the other hand, externally ballasted barricades deform under the weight of sandbags. When barricade assemblies are struck by a moving vehicle, for example, their structural integrity also leaves something to be desired. When components are damaged, they cannot be readily cannibalized for use in other barricade assemblies. Many of them are not sufficiently compact to permit stacking large quantities of assembled barricades together for transport.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide an improved plastic barricade assembly.
Another object is to provide a plastic traffic barricade assembly which has a high degree of structural integrity.
Yet another object is to provide a plastic traffic barricade assembly which can be easily cannibalized for parts if it is damaged in use.
Still another object is to provide a plastic traffic barricade assembly which, although employing ruggedly substantial leg components, collapses into a narrow profile for storage and shipping.
A further object is to provide a plastic traffic barricade assembly comprising separately blow molded leg and panel members fastened together in interlocking relationship.
Yet a further object is to provide a plastic traffic barricade assembly wherein said separately molded leg and panel members are rigidly interconnected after molding to form two substantially identical leg and panel units which are then pivotally connected.
Still a further object is to provide a new and improved method of constructing a plastic traffic barricade assembly.
The foregoing and other objects are realized in accord with the present invention by providing a barricade assembly comprising separate leg and panel members blow-molded of high molecular weight polyethylene plastic. Two identical leg and panel units are assembled, each from first and second different leg members and a plurality of panel members. The first leg members of each unit are identical to each other. The second leg members of each unit are, in turn, identical to each other.
The leg members are all molded with body sections which have I-beam shaped cross-sections, including opposed flanges interconnected by a web. This configuration permits the leg members to be quite narrow, i.e., the flanges are one-and-one-half (11/2") inch wide in a conventional size barricade.
The outer flanges on each leg member in a leg and panel unit have elongated depressions formed therein, each for receipt of a panel. Each panel, in turn, has a corresponding one-and-one-half inch (11/2") wide channel formed in its back face for mating, in interlocking fashion, with a leg member depression. The panel members are bolted to each of first and second leg members in this relationship to form a leg and panel unit.
Two leg and panel units are then mated with each other, panel members facing outwardly, by interconnecting bearing elements and bearing bores molded unitarily into the head sections of first and second leg members, respectively. The bearing element and bore of corresponding pairs of head sections contain cam action limit stops which then limit spreading of the leg and panel units to a degree desirable for use. The head section of each of the first leg elements also has an ear formed in it which is adapted to engage the upper edge of a panel member on the opposite leg and panel unit to provide a second limit stop for unit opening.
The leg and panel units are bolted together on common axes which are offset from the centerlines of corresponding leg members by a distance corresponding to the panel members' thickness. This permits the leg and panel units to nest flat against each other when the barricade assembly is collapsed for storage or use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a barricade assembly embodying features of the present invention;
FIG. 2 is a front elevational view of the barricade assembly;
FIG. 3 is a front elevational view of one leg and panel unit for the barricade assembly;
FIG. 4 is a side elevational view of the leg and panel unit of FIG. 3;
FIG. 5 is a side elevational view of a first leg member for the leg and panel unit of FIG. 3;
FIG. 6 is a front elevational view of the first leg member seen in FIG. 5;
FIG. 7 is an enlarged side view (from the back) of the head section in the leg member seen in FIG. 6;
FIG. 8 is a sectional view taken along line 8--8 of FIG. 5;
FIG. 9 is a front plan view of a panel member from the leg and panel unit of FIG. 3;
FIG. 10 is an edge elevational view of the panel member seen in FIG. 9;
FIG. 11 is a bottom plan view of the panel member seen in FIG. 9;
FIG. 12 is a side elevational view of the second leg member for the leg and panel unit of FIG. 3;
FIG. 13 is a front elevational view of the second leg member seen in FIG. 12;
FIG. 14 is an enlarged side view (from the back) of the head section in the leg member seen in FIG. 13;
FIG. 15 is a vertical sectional view through the head sections of first and second leg members, as assembled;
FIG. 16A is a diagrammatic view of the pivot bearing and locking cam relationship, open position;
FIG. 16B is a view similar to FIG. 16A showing the closed position relationship;
FIG. 17 is an enlarged side elevational view of the assembly of FIGS. 1 and 2, but in its closed relationship; and
FIG. 18 is a sectional view taken along line 18--18 of FIG. 17, with parts removed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and particularly to FIGS. 1 and 2, a plastic barricade assembly embodying features of the present invention is seen generally at 5. The assembly 5 is comprised of a pair of identical leg and panel units 10 and 110. Only leg and panel unit 10 will be described in detail, it being understood that the leg and panel unit 110 is identical to it. Throughout the specification, all parts of the leg and panel unit 110 are numbered exactly as their counterparts in leg and panel unit 10, with an added 100 digits.
Each leg and panel unit 10 comprises three horizontal panel members 21, 22 and 23, and two vertical leg members 31 and 32. Each of the members 21, 22 and 23, and 31 and 32 is separately blow molded of a high molecular weight polyethylene plastic. The members 21, 22 and 23, and 31 and 32, and corresponding members 121, 122 and 123, and 131 and 132, are assembled in a manner hereinafter discussed to create the assembly 5.
Referring now to FIGS. 3 and 4, a separate leg and panel unit 10 is shown. The panel members 21, 22, and 23, and the leg members 31 and 32 of the leg and panel unit 10 are rigidly interconnected, according to the invention, to assemble the unit 10.
As will be seen, the panel members 21, 22 and 23 are mounted on, and interconnected with, the leg members 31 and 32. The leg members 31 and 32 are spaced approximately twenty inches (20") apart in a standard size barricade.
The panel member 21 is fastened, adjacent one of its ends, to the leg member 31 by bolts 21a and nuts 21b. Similarly, the panel member 22 is fastened to the leg member 31 adjacent one end of the panel member by bolts 22a and nuts 22b. Likewise, the panel member 23 is fastened to the leg member 31 adjacent one end of this panel member by bolts 23a and nuts 23b.
The panel member 21 is, in turn, fastened to the leg member 32 by bolts 21c and nuts 21d. In turn, the panel member 22 is fastened to the leg member 32 by bolts 22c and nuts 22d. Finally, the panel member 23 is fastened to the leg member 32 by bolts 23c and nuts 23d. In contrast to their attachments to the leg member 31, however, the panels members 21, 22 and 23 are fastened to the leg member 32 at a greater distance from the opposite ends of corresponding panel members, as will be seen. This distance is greater by an amount corresponding to the width of a leg member 31 or 32, as seen in FIG. 3; and one-and-one inch (11/2") in a barricade of standard size. Thus, the panel members 21, 22 and 23 are mounted in laterally offset relationship relative to the leg members 31 and 32. As a result, when the panel units 10 and 110 are assembled in face to face relationship, in a manner hereinafter discussed, the panel members 21, 22 and 23 on opposed panel units have their opposite ends aligned with each other, as seen in FIG. 2.
The bolts 21a and 21c, 22a and 23a and 23c extend from their low-profile heads (seen in FIG. 3), which engage the panels 21, 22 and 23, respectively, through suitably formed aperatures in the panels and corresponding legs 31 or 32, in a manner hereinafter discussed in detail. The free ends of the bolts are threaded and receive corresponding nuts, 21b and 21d, 22b and 22d, and 23b and 23d.
Referring now to FIGS. 5-8, a disassembled leg member 31 is illustrated. The leg member 31, which is blow molded in one piece, includes an elongated center section 41, a foot section 42 and a head section 43. As is characteristic of blow molding, of course, the leg member 31 is essentially hollow, with a wall thickness of approximately 0.125 inches.
The central section 41 is molded with an I-beam cross-section, as best seen in FIG. 8. The I-beam cross-section is defined by outer flange 45 and inner flange 46 connected by web 47. The wall which forms the leg member 31, in its central section 41, is spaced apart along most of the central section. However, in the blow molding process, a plurality of inwardly extending offsets or "tacks" 48 and 49 are formed in the web 47, from one side thereof and those tacks become welded to the other side of the web during the molding process. The tacks 48 help to rigidify the central section 41. The tacks 49 bracket bolt holes, hereinafter discussed, to strengthen the central section 41 at these bolt holes.
The outer flange 45 of the central section 41 is also molded with inwardly extending offsets in three areas to form three elongated depressions 51, 52 and 53 in its outer surface. The lengths of each of these depressions corresponds to the height of a corresponding panel member 21, 22 and 23, a subject hereinafter discussed. The depth of each of these depressions 51, 52 and 53 is one-half the thickness of each panel member, but each depression has at least one deeper cut-out (see 51 a in FIG. 5, for example), for reasons hereinafter discussed. According to the invention, this configuration permits a highly effective, interlocking relationship of panel members 21, 22 and 23 and leg member 31 when a panel unit 10 is assembled.
The central section 41 of the leg member 31 also has the aforementioned bolt holes 55 formed vertically through it, from flange 45 to flange 46, inside the web 47. Bolt holes 55 are formed through the leg member 31 in each of the three depressions 51, 52 and 53. As will hereinafter be discussed, the panel numbers 21, 22 and 23 are fastened to the leg member 31 with corresponding bolts which extend through these bolt holes 55.
The foot section 42 of the leg member 31 is defined by a thickened end flange 56 formed in the molding process. The flange 56 defines a ground engaging surface for the leg member 31.
The head section 43 of the leg member 31 includes a radially extending ear 58. As will also hereinafter be discussed, the ear 58 is arranged to engage the upper edge of the panel member 121 when the barricade assembly 5 is opened for operation and serve as a limit stop for opening travel of the two panel sections 10 and 110 as they are spread for use.
Referring to FIGS. 6 and 7, the head section 43 also has an annular stub bearing 60 formed outwardly from one side. The axis of the stub bearing 60, which serves as a pivot axle for the panel units 10 and 110 when they are connected, is spaced from the centerline C/L of the leg member 31 by a distance d corresponding to the thickness of each of the panel members 21, 22 and 23; the centerline of a panel unit being defined here as a line extending longitudinally of the leg member half-way between the flanges 45 and 46. This offset, which is toward the inside of the leg member 31, permits the panel units 10 and 110 to nest flat against each other when they are collapsed, also in a manner hereinafter discussed.
The annular stub bearing 60 has a radially protruding cam 61 formed unitarily with it. This cam 61 acts as another limit stop for opening travel of the two panel sections, in a manner hereinafter discussed.
The annular stub bearing 60 has a bolt hole 62 formed through it on its axis. This bolt hole 62 also extends through the wall of the head section 32 opposite the bearing 60. The function of this bolt hole 62 in the barricade assembly 5 will be hereinafter discussed.
Referring now to FIGS. 9-11, a separate panel member 21 is illustrated. The panel member 21 is blow molded of plastic so that its walls are also about 0.125 inch thick. The panel, itself, is one-half inch (1/2") thick. As such, a cavity 65 is defined within the panel member 21.
The outer wall 66 of the panel member 21 has an essentially smooth outer surface, although outwardly extending ridges 66a are formed horizontally along its upper and lower edges. This facilitates the surface-to-surface fastening of reflective sheeting, for example, between the ridges 66a.
The inner wall 67 of the panel 21 has two discontinuous mounting channels 68 and 69 molded into its outer surface. One of these channels, channel 68, is formed into the wall 67 three-quarters of an inch (3/4") from an end 70a of the panel 21. This channel 68 is one-quarter inch (1/4") deep and one and one-half inch (11/2") wide, except where it is discontinuous, at 68a, 68b and 68c, the discontinuities creating air passages through the channel 68 for molding purposes. The other channel, channel 69, is formed into the wall 67 one-and-three quarters of an inch (13/4") from the other end 70b of the panel 21. This channel 69 is also one-quarter inch (1/4") deep and one inch (1") wide, except where it is discontinuous, at 69a, 69b and 69c, the discontinuities creating internal air passages for blow-molding purposes.
The panel member 21 also has two bolt holes 71 formed through it in the channel 68. These bolt holes 71 are for the bolts 21 a which attach the panel member 21 to the leg member 31. Two more bolt holes 72 are formed through the panel member 21 in the channel 69. These bolt holes 72 are for the bolts 21c.
In the inner wall 67 of the panel member 21, a pattern of cup-shaped indentations 73 are formed inwardly from the outer surface of that wall. These indentations 73 extend into engagement with the inner surface of the outer wall 66 of the panel member 21, and form "tacks" between the walls 66 and 67 by bonding during molding. Four of the cup-shaped indentations, seen at 74, serve an additional purpose, as will hereinafter be discussed.
Panel members 22 and 23 are identical in construction to panel member 21, except for their width dimensions and number of bolt holes. The panel member 21 is twenty four inches (24") long and twelve inches (12") wide. The panel member 22 is eight and one quarter inches (81/4") wide. The panel member 23 is three inches (3") wide.
Turning now to FIGS. 12-14, the leg member 32 is also seen separately. FIG. 12 illustrates the leg member 32 as it would be seen from the right in FIG. 2. FIG. 13 shows the same leg members 32 from the front. FIG. 14 is an enlarged view of the head section 75 of the leg member 32.
As has previously been pointed out, the leg member 32 is identical to the leg member 31, except for the construction of the head section 75. Accordingly, except for the head section 75, all components of the leg member 32 bear the same reference numerals as the leg member 31.
The head section 75 of the leg member 32 includes an elongated crown 76 which forms a bracket for attachment of a flasher warning light unit (not shown). To this end, it will be seen that the crown 76 has a well 77 formed in one side for receipt of a light unit mounting base and attachment bolt (not shown). A bolt hole 78 is formed through the crown 76 in the well 77 for receipt of a bolt (not shown) which attaches the light unit.
Referring to FIG. 14, the head section 75 also has an annular bearing bore 80 formed inwardly from one side. The bearing bore 80, which serves as a pivot axle bearing for the panel units 10 and 110 when they are connected has, like the stub bearing 60 on the leg member 31, an axis which is offset from the centerline C/L of the leg member 32 by the distance d hereinbefore referred to, and for the same purpose.
The annular bearing bore 80 has a radially extending lobe 81 covering an arcuate distance corresponding generally to the travel which the aforedescribed cam 61 is permitted when the panels 10 and 110 are spread to operational relationship. The mating of the stub bearing 60 and bore 80, cam 61 and bore lobe 81, will hereinafter be further discussed.
The annular bearing bore 80 also has a bolt hole 82 formed through its base, at its axis. The bolt hole 82 also extends through the wall of the head section 75 opposite the bearing bore 80.
All of the components of a leg and panel unit 10 have now been described and illustrated. In effect, then, all the components of the leg and panel unit 110 have also been described and illustrated, since they are identical. Now, the method of assembly of the leg and panel units 10 and 110 and, finally, the mating of those units to form the assembly 5, will be described.
A leg and panel unit 10 is assembled by seating three panel members 21, 22 and 23 on the leg members 31 and 32 and securely fastening them with bolts 21a and 21c, 22a and 22c, and 23a and 23c, and with nuts 21b and 21d, 22b and 22d, and 23b and 23d. The channels 68 and 69 in each of the panels 21, 22 and 23 are seated in corresponding elongated depressions 51, 52 and 53 in the leg members 31 and 32. Because the depth of each channel 68 and 69 is one-half the thickness of the panel member (except at the discontinuities 68a and 69a), and the depth of each depression 51, 52 and 53 is the same (except for discontinuities 51a, etc.), the panel members 21, 22 and 23 seat in interlocking relationship with the leg members 31 and 32 while, at the same time, their outer surfaces are substantially flush with the surfaces of the flanges 45 between those recesses. The discontinuities 68a, 68b, 68c and 69a, 69b and 69c in the channels 68 and 69 in panel member 21, for example, mate with corresponding discontinuous cut-outs 51a (see 51a in FIG. 6) molded into the depression 51. The panel members 22 and 23 seat in the same way. This interlocking relationship of panel members and leg members creates leg and panel units which can absorb great impact loads without breaking up.
With the panel members 21, 22 and 23 bolted in place on the leg members 31 and 32, the nuts 21b and 21d, 22b and 22d, and 23b and 23d protrude outwardly of the flanges 46, as do the threaded bolt ends to which they are attached. At the same time, the heads of each bolt 21a and 21c, 22a and 22c, and 23a and 23c are relatively low in profile so that they protrude only slightly. The implication of this construction in the context of the invention will shortly be discussed.
Next, another leg and panel unit is assembled of identical components, in this case the leg and panel unit 110. The two identical leg and panel units 10 and 110 are then placed in face-to-face relationship, so-to-speak, with their respective panel members 21-23 and 121-123 facing outwardly. The stub bearings 60 and 160 on the leg members 31 and 131 are introduced into the bearing bores 180 and 80 on the leg members 132 and 32, respectively, by moving the leg and panel units 18 and 110 traversely of each other. The ears 61 on the stub bearings 60 then lie within the confines of the corresponding bore lobes 81.
At this point, referring to FIG. 15, a bolt 85 is passed through the aligned bolt holes 62 and 82 in the head sections 32 and 75 of each mated pair of leg members, i.e. leg members 31, 132 and 32, 131. A nut 86 is turned onto the threaded end of each nut 85. The panel units 10 and 110 are securely connected in this way to form the barricade assembly 5.
FIGS. 1 and 2 show the completed assembly 5 in its open position, ready for use. In this position, the ear 58 on the head section 32 of the leg member 31 has engaged and is stopped against the upper edge of the panel member 121 in the leg and panel unit 110. At the same time, the ear 158 on the head section 132 of the leg member 131 has engaged and is stopped against the upper edge of the panel member 21 in the leg and panel unit 10.
At the same time, further spreading of the leg and panel units 10 and 110 is also stopped by the cams 61 and 161. These cams 61 and 161 reach the limit of their travel in corresponding lobes 81 and 181 of mating bearing bores 80, as is illustrated in FIG. 16A. Thus, integrity of the assembly 5 is insured by providing dual limit stops associated with each mating pair of leg members.
The construction of the leg members 31, 32 and 131, 132, and the manner in which they are connected to corresponding panel members produces, according to the invention, particularly high resistance to deformation under load. As a result, external weights in the form of sandbags, for example, do not cause the assembly 5 to sag over time.
When it is desired to collapse and store or ship the assembly 5, the leg and panel units are pivoted toward each other, about the co-axial axes of the bearings 60, 160 and bearing bores 80, 180 (which are also the axes of the bolts 85). Because these axes are offset from the centerlines of corresponding leg members by the thickness of the panel members 21-23 and 121-123, the leg and panel units 10 and 110 can collapse into the nested relationship seen in FIG. 17. In this configuration, the cams 61 and 161 are in the positions shown in FIG. 16B.
The intimacy of the nested relationship is also enhanced by mating of the nuts 21b and 121b, 22b and 122b, and 23b and 123b with corresponding cup-shaped depressions 74 formed in the back of each panel member 21-23 and 121-123. This relationship is shown in FIG. 18, where it will be seen that when the leg and panel units 10 and 110 are collapsed against each other, corresponding nuts 21b, etc. (with associate bolt ends) are, in effect, housed within corresponding depressions 74.
The preferred embodiment of the barricade assembly 5 has been discussed in terms of a traffic barricade. However, it should be understood that the invention might also take the form of some other kind of barricade or sign support assembly, for example. Regardless of which, the structure is compact, highly resistant to impact load, able to easily support sand-bag weights without deforming and readily cannibalized for components.
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A plastic barricade assembly including two leg and panel units pivotally interconnected. Each leg and panel unit comprises first and second leg members and a plurality of panel members, the members being separately blow molded. The first leg members of each leg and panel unit are identical to each other and, at the same time, different than the second leg members of each leg and panel unit which are, in turn, identical to each other. Each leg and panel unit is assembled by bolting a first and second leg member together with a plurality of panel members. The leg and panel members of each unit are bolted together in interlocking relationship.
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FIELD OF THE INVENTION
The present invention relates to a pedestrian protection system for a motor vehicle, e.g., having an impact detection sensor for detecting an impact of a pedestrian on the motor vehicle as well as a bumper for a motor vehicle, the bumper including a support made of a stiff material, an outer skin for covering the bumper and an elastic layer situated between the support and the outer skin.
BACKGROUND INFORMATION
Pedestrian protection systems are described, e.g., in European Published Patent Application No. 0 914 992 and German Published Patent Application No. 100 16 142 as well as from the related art discussed in German Published Patent Application No. 100 16 142. German Published Patent Application No. 100 16 142 describes, e.g., a person protection system having a trigger switch, the trigger switch having a first pair of contacts and at least one second pair of contacts which is operable by pressure and by which an electric circuit may be closed and thereby a contact signal produced, the first and the second pair of contacts being situated at a spatial distance from each other.
SUMMARY
Example embodiments of the present invention may provide an improved pedestrian protection system. For this purpose it is desirable to find a particularly good compromise between a low false triggering of the pedestrian protection system, a reliable triggering of the pedestrian protection system in the event of an impact of a pedestrian on the motor vehicle and a quick triggering of the pedestrian protection system in the event of an impact of a pedestrian on the motor vehicle.
A pedestrian protection system for a motor vehicle may include an impact detection sensor for detecting an impact of a pedestrian on the motor vehicle, the impact detection sensor being situated in a front bumper of the motor vehicle near an outer skin for covering the bumper and/or in a front part of the motor vehicle near an outer skin for covering the front part of the motor vehicle. In this connection, when a collision with a pedestrian is detected, the impact detection sensor may trigger a protective mechanism such as, e.g., a raising of an engine hood as described, e.g., in German Published Patent Application No. 100 16 142.
The impact detection sensor may have a side facing the outer skin and a side facing away from the outer skin, the side of the impact detection sensor facing away from the outer skin being, e.g., less than 25 mm away from the outer skin. The side of the impact detection sensor facing the outer skin may substantially or nearly touch the outer skin.
A bumper for a motor vehicle includes a support made of a stiff material, e.g., steel, an outer skin for covering the bumper and an elastic layer (such as, e.g., a foam member) situated between the support and the outer skin, and the bumper having an impact detection sensor, situated between the support and the outer skin near the outer skin, for detecting an impact of a pedestrian on the motor vehicle. In this connection, when a collision with a pedestrian is detected, the impact detection sensor may trigger a protective mechanism such as, e.g., a raising of an engine hood as described, e.g., in German Published Patent Application No. 100 16 142.
The impact detection sensor may have a side facing the outer skin and a side facing away from the outer skin, the side of the impact detection sensor facing away from the outer skin being, e.g., less than 25 mm away from the outer skin. The side of the impact detection sensor facing away from the outer skin essentially or nearly touches the elastic layer.
In another advantageous refinement of the present invention, the side of the impact detection sensor facing the outer skin may substantially or nearly touch the outer skin.
The elastic layer may include foamed material or may be made up substantially of foamed material.
A motor vehicle—e.g., including the above-mentioned characteristics—may have a first impact detection sensor for detecting an impact of a pedestrian on the motor vehicle and at least one second impact detection sensor for detecting an impact of a pedestrian on the motor vehicle, the first impact detection sensor being situated in a front bumper of the motor vehicle, e.g., at a distance of less than 25 mm from an outer skin for covering the bumper and/or in a front part of the motor vehicle at a distance of less than 25 mm, e.g., less than 10 mm, from an outer skin for covering the front part of the motor vehicle, and the second impact detection sensor, e.g., being situated on a pedestrian protection support of the motor vehicle.
Impact detection sensors may be, e.g., contact sensors (such as fiber-optic sensors for example), force sensors or sensors arranged according to the sensor described in German Published Patent Application No. 100 16 142.
An arrangement near an outer skin may include an arrangement at a distance of, e.g., less than 25 mm, e.g., less than 10 mm, from the outer skin.
A motor vehicle may include a land vehicle that may be used individually in road traffic. Motor vehicles are not, however, restricted to land vehicles having an internal combustion engine.
Further aspects and details of exemplary embodiments of the present invention are described below with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary embodiment of a pedestrian protection system of a motor vehicle.
FIG. 2 is a cross-sectional view through a segment of the front part of the motor vehicle illustrated in FIG. 1 .
FIG. 3 is a front view of a motor vehicle.
FIG. 4 is another front view of a motor vehicle.
DETAILED DESCRIPTION
FIG. 1 illustrates a pedestrian protection system 16 , modified with respect to the person protection system described, e.g., in German Published Patent Application No. 100 16 142, for a motor vehicle 10 for protecting pedestrians 14 .
The pedestrian protection system 16 has a raisable engine hood 22 , which is raisable using an engine hood airbag device 24 . In order to prevent a firing of engine hood airbag device 24 from raising engine hood 22 more than a predefined distance, an engine hood catching device 25 in the form of a cable line, a chain or a stop is provided. Engine hood includes, e.g., a covering of a space lying in front of a passenger compartment of a motor vehicle.
Pedestrian protection system 16 includes a control system 31 by which the engine hood airbag device 24 is triggered if a collision with a pedestrian 14 is detected by an impact detection sensor 32 illustrated in FIG. 1 and situated in a front bumper 30 . For this purpose, control system 31 and impact detection sensor 32 are suitably connected to each other in terms of data technology.
If the velocity of the motor vehicle, which is determinable with the aid of impact detection sensor 32 using an impact detection sensor, such as that described, e.g., in German Published Patent Application No. 100 16 142, lies within a predefined velocity window of, e.g., 20 km/h to 50 km/h, then the pyrotechnic charge of engine hood airbag device 24 is triggered. If the velocity lies above the velocity window, then control system 31 locks engine hood 22 using a locking device 48 , which, e.g., secures catching device 25 . An activation of the pyrotechnic charge of engine hood airbag device 24 does not occur.
FIG. 2 is a cross-sectional view through a segment of the front part of motor vehicle 10 including bumper 30 in a detailed view. Bumper 30 includes a steel support 35 , on whose side 39 facing the front side of motor vehicle 10 a solid or honeycomb-structured foam member 34 is situated. Foam member 34 is covered by an outer skin 33 .
Bumper 30 has an impact detection sensor 32 situated between steel support 35 and outer skin 33 —e.g., between foam member 34 and outer skin 33 —at a distance of, e.g., less than 25 mm from the outer skin. The present exemplary embodiment provides for impact detection sensor 32 or for side 45 of impact detection sensor 32 facing outer skin 33 substantially or nearly to touch outer skin 33 . Side 46 of impact detection sensor 32 facing away from outer skin 33 is, e.g., less than 25 mm away from outer skin 33 . In addition, side 46 of impact detection sensor 32 facing away from outer skin 33 substantially or nearly touches foam member 34 .
There may be an optional provision for motor vehicle 10 to have at least one additional impact detection sensor 36 for detecting an impact of a pedestrian 14 in or on a pedestrian protection support 37 of motor vehicle 10 . In this instance, there may be a provision for control system 31 to evaluate also a time difference between a signal of impact detection sensor 32 indicating an impact and a signal of impact detection sensor 36 indicating an impact in order to differentiate between an impact of a pedestrian 14 from an impact of an object, for example.
Impact detection sensors 32 and 36 may be, e.g., contact sensors (such as fiber-optic sensors, for example), force sensors or sensors arranged according to the sensor described, e.g., in German Published Patent Application No. 100 16 142. Sensors arranged in accordance with the sensor described in German Published Patent Application No. 100 16 142, that is, sensors having at least one, e.g., two pairs of contacts, which by contact close an electric circuit in the event of an impact, may be provided for impact detection sensor 32 , that is, an impact detection sensor situated in a bumper.
FIG. 3 and FIG. 4 each show a front view of a motor vehicle 50 or 60 . In this instance, reference numerals 51 , 52 , 61 , 62 , 63 and 64 indicate regions (e.g., not visible from outside), in which impact detection sensors may be situated in a segmented or in a continuous manner. Thus, e.g., motor vehicle 50 may correspond to motor vehicle 10 , it being possible for impact detection sensor 32 to be situated in a segmented or in a continuous manner in region 51 and impact detection sensor 36 to be situated in a segmented or in a continuous manner in region 52 . Motor vehicle 60 may also correspond to motor vehicle 10 , for example, it being possible for impact detection sensor 32 to be situated in a segmented or in a continuous manner in regions 61 , 62 and 63 . There may also be a provision, alternatively or additionally to impact detection sensor 36 , for an impact detection sensor to be situated in region 64 .
LIST OF REFERENCE NUMERALS
10 , 50 , 60 motor vehicle
14 pedestrian
16 pedestrian protection system
22 engine hood
24 engine hood airbag device
25 engine hood catching device
30 bumper
31 control system
32 , 36 impact detection sensor
33 outer skin
34 foam member
35 steel support
37 pedestrian protection support
39 side of a steel support facing the front side of a motor vehicle
45 side of an impact detection sensor facing the outer skin
46 side of an impact detection sensor facing away from the outer skin
48 locking device
51 , 52 , 61 , 62 ,
63 , 64 region
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A pedestrian protection system for a motor vehicle includes an impact recognition sensor for recognizing an impact of the motor vehicle with a pedestrian. The impact recognition sensor is located in a front fender of the motor vehicle, next to an outer skin that lines the fender, or in a front part of the motor vehicle, next to an outer skin that lines the front part of the motor vehicle.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of joining metallic parts. In particular, the present invention relates to a method of joining superalloy sub-components and repairing a component by removing a damaged portion and re-inserting a replacement section.
[0003] 2. Description of Related Art
[0004] Industrial gas turbine (IGT) blades are produced in one of three basic forms: equiaxed, directionally solidified or single crystal. In any of these cases, castings for IGT blades have become extremely large and costly. As the blades become larger and the casting processes become more sophisticated, casting yields tend to decrease, resulting in extra re-melting and casting costs in an effort to recycle defectively produced blades. Low casting yields of large turbine blades also make large volume manufacturing inefficient and expensive. This decrease in casting yields can be attributed to the fact that the casting of large sections inherently induces more defects. To avoid this issue, many manufacturers have been finding ways to join smaller blade components, known as sub-assemblies, to form a single large turbine blade.
[0005] Moreover, modem high temperature superalloy articles, such as nickel-based, precipitation strengthened superalloys used in the manufacture of rotating gas turbines blades, comprise complex alloys at the cutting edge of high temperature metallurgy. Over the years, superalloy materials have been developed to provide mechanical strength to turbine blades and vanes operating at high temperatures. As these turbine blades are difficult and expensive to manufacture, it is desirable to repair a damaged blade than to replace one.
[0006] Typically, aero and IGT hot section components are repaired using either welding or brazing methods. Both methods have been successfully applied to a variety of hot section turbine component materials including nickel-, cobalt-, and iron-based superalloys. Stationary components, such as vanes (also known as nozzles), transition pieces, or combustor liners or combustors are the most often repaired hot section components. Repairs on stationary components may be performed over virtually the entire component due to the lower stresses experienced during operation because these components experience only operational and thermal stresses and do not experience the high rotational stresses experienced by blades (buckets) or discs.
[0007] However, various issues or limitations appear when brazing or welding methods have been used to repair turbine blades. For example, narrow gap brazing techniques have been plagued by joint contamination that results in incomplete bonding, even when elaborate thermo-chemical cleaning processes precede the brazing operation. Narrow gap brazing also lacks the ability to restore damaged or missing areas on the blade. Joints formed using wide gap brazing methods can be difficult to set-up, and porosity in the deposited filler material continues to be a concern. Gas Tungsten Arc Welding (GTAW) and Plasma Transferred Arc Welding (PTAW), while the most commonly used methods for blade repairs today, require the use of lower strength fillers in order to avoid cracking, which limits which parts of the blade that can be welded.
[0008] Due to these limitations, blade repairs are limited to the lower stress regions of the blade airfoil. Thus, some 80 to 90 percent of blade surfaces are non-repairable, and such non-repairable blades are generally returned to suppliers as scrap for credit against replacement blades. The financial impact of this is significant for the utility industry. For example, a single air-cooled, row 1 rotating blade may cost up to thirty-five thousand dollars to replace, and, depending on the turbine manufacturer and model, there are approximately 90 to 120 blades in a typical row. Thus, the need to develop an improved method to repair damaged blades by joining the damaged blade with a replacement superalloy piece would be desirable.
[0009] As noted, it would be desirable to provide an improved technique for joining superalloy parts, such as superalloy turbine blade sub-assemblies, that are subject to high temperatures and stresses, including operational, thermal, and rotational stresses. It also would be desirable to provide an improved technique for repairing damaged turbine blades by joining the damaged blade with a replacement superalloy piece, regardless of the location of the damaged area.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention provides a method for joining metallic members, which can be used to join component sub-assemblies. Further, the present invention provides a method for repairing a component by removing a damaged portion and re-inserting a replacement section.
[0011] In general, the present invention provides in one embodiment a method for joining metallic members comprising: preparing a surface of a first metallic member, thereby providing an oxide-free surface; preparing a surface of a second metallic member, thereby providing an oxide-free surface; applying pressure to the first and second metallic members, thereby forcing the surface of the first metallic member and the surface of the second metallic member together and forming a joint area; sealing an outer edge of the joint area; and subjecting the members to a hot isostatic process operation. In other embodiments, the surface of the first metallic member and the surface of the second metallic member may each comprise an interlocking section, in which the interlocking section of the first metallic member fits into the interlocking section of the second metallic member.
[0012] In another embodiment, the present invention provides a method for joining metallic members comprising: preparing a surface on a first metallic member and a surface on a second metallic member by surface grinding, grit blasting, grinding, polishing, chemical cleaning or combinations thereof; positioning the surface on the first metallic member physically against the surface on the second metallic member are brought tightly together, thereby forming a joint area, wherein the positioning further comprises applying pressure on the first metallic member and the second metallic member to ensure closer physical contact between the surface on the first metallic member and the surface on the second metallic member; sealing an outer edge of the joint area by a seal weld; and subjecting the members to a hot isostatic processing operation.
[0013] Moreover, the present invention provides in an embodiment a method for repairing a work piece, comprising: replacing a damaged portion of a work piece with a metallic member; preparing a surface of the work piece; preparing a surface of the metallic member; applying pressure to the work piece and the metallic member, thereby forcing the surface of the work piece and the surface of the metallic member together and forming a joint area; sealing an outer edge of the joint area; and subjecting the members to a hot isostatic process operation. In alternative embodiments, the surface of the work piece and the surface of the metallic member may each comprise an interlocking section, in which the interlocking section of the work piece fits into the interlocking section of the metallic member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a flowchart illustrating a method according to one embodiment of the present invention;
[0015] FIG. 2 is a flowchart showing a method according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Generally, the present invention provides an improved method for joining metallic parts, specifically, superalloy sub-components, to form a single metallic component. The present invention also provides an improved method for repairing a superalloy metallic component by removing the damaged portion with a new portion rather than completely replacing the component. Additionally, the present invention provides an improved method that helps form stronger joints between metallic parts, even in areas subject to high stress and temperatures. The following text in connection with the Figures describes various embodiments of the present invention. The following description, however, is not intended to limit the scope of the present invention.
[0017] FIG. 1 is a flowchart illustrating a method according to one embodiment of the present invention. A process 100 is used in joining metallic parts. In step 110 , the metallic parts are first prepared, to reduce the amount of oxide on the surfaces of the metallic parts and to clean the surfaces. Any suitable means can be employed to prepare the surfaces, as long as the surfaces become clean and the oxide is reduced to a minimum, preferably making the surface oxide-free after preparation. In a preferred embodiment, step 110 can be achieved by a combination of surface grinding, grit-blasting, grinding/polishing, or fluoride ion cleaning (FIC). After the surfaces have been prepared, some care should be exercised in the handling of the metallic parts so that the joining surfaces do not get. inadvertently contaminated, damaged or oxidized. A clean and oxide-free surface facilitates the eventual formation of a strong metallurgical bond. It is also advisable to process the metallic parts shortly after this preparation step 110 .
[0018] It should be appreciated that the two metallic parts to be joined can be any type of steel. However, in a preferred embodiment, the present invention is used to join superalloy steel pieces together and more preferably to join nickel-based or cobalt-based superalloy pieces. It should be appreciated that the present invention enables these types of superalloy steel pieces to be joined to form or repair turbine blades, turbine vanes, jet engine components, or other components used in aerospace applications.
[0019] In the next step 120 , the pieces are positioned together. The prepared surfaces of the two metallic parts are brought into physical contact with each other, thereby creating mating surfaces for the joint to be formed. Any means can be used to bring the mating surfaces together such as, but not limited to, manually positioning the metallic parts together or using a custom device to guide the metallic parts so that they contact each other at precise locations on the mating surfaces. Pressure is then applied to the metallic parts to minimize any space between the mating surfaces. Any means known in the art can be used to apply pressure, such as, but not limited to, placing the metallic parts in a vise. The amount of pressure varies, depending on how easily close, tight contact can be achieved between the metallic pieces, which may be a function of size, geometry, and other physical conditions of the mating surfaces. However, pressure should not be misapplied such that the metallic parts, especially the mating surfaces, become inadvertently damaged. Thus, some care should be exercised when applying pressure with respect to the amount of pressure and the direction in which the pressure is applied.
[0020] Subsequently in step 130 , the joint formed where the mating surfaces are in contact is then sealed. A seal weld is preferably applied around the outer edge of this joint area, which also establishes the necessary pressure boundary between the mating surfaces. Any welding means known by one of skill in the art can be used to create the seal weld such as, but not limited to, gas welding, flux-cored arc welding, metal-cored arc welding, gas metal arc welding, submerged arc welding, gas tungsten arc welding, plasma transferred arc welding, electroslag welding, laser beam welding, electron beam welding, etc. The seal weld should cover all outer edges of the joint area to prevent any contamination or fluid leakage into the joint area. The seal weld is important in that it eliminates the potential for oxidation or contamination during hot isostatic processing (HIP), which can lead to poor bonding between the two metallic parts. Even though the seal weld in this embodiment does provide some means to join the two metallic pieces, it is not designed to provide mechanically strong connections, unlike the welds created by welding filler materials to the mating surfaces of work pieces. The seal weld must be suitable to withstand the pressure of HIP without rupture. Rupture of the seal weld would lead to failure of the bond due to equalization of the HIP pressure with the contact pressure of the mating faces.
[0021] It should be appreciated that the sealing of the outer edges of the joint area of the two metallic parts is not limited to the use of seal welds. Any suitable sealing media may be used to seal off the outer edges of the joint area. Given that the metallic parts will be undergoing HIP, the sealing media must be one that can withstand the high temperature and high pressure environment of HIP. For example, high temperature waxes similar to those used in the casting industry may be used as a sealing media. Further, one skilled in the art can use any suitable sealing method as long as the other types of seals do not degrade when the metallic parts undergo HIP. For example, the use of brazing to seal off the joint area is likely ineffective because most braze fillers would break down at HIP temperatures.
[0022] In step 140 , after the outer edges of the joint area have been properly sealed off, the joined metallic parts undergo HIP. HIP can be performed in a pressure vessel or furnace, in which the joined metallic parts are subject to high temperatures and isostatic gas pressure (usually inert, i.e., argon). The maximum temperature and pressure for HIP vessels is about 2000° C. and 175-200 MPa, respectively. The operational pressure ranges of HIP can be between 100 to 200 MPa. The operational temperature ranges of HIP can be within 50% to 80% of the metallic parts' melting temperature, which is usually in the temperature range for solution annealing.
[0023] Solutioning can be beneficial for nickel-based alloys to render them less brittle and more workable. The metal and other included materials are heated to a common phase and then cooled very rapidly and uniformly with time and temperature to prevent any subsequent precipitation of secondary phases such as gamma prime, which tends to strengthen the overall alloy matrix and thus provides resistance to HIP pressures. These temperatures, coupled with the high pressures generated from the HIP process, tend to close voids that might have existed in the original casting as well as those that are induced by creep deformation during service exposure. Closing these voids aids in crack prevention since it lowers the number of potential crack initiation sites. HIP also re-establishes the gamma/gamma prime microstructure that provides much of the material's strength. Even though HIP is used to re-condition the microstructure of the alloy to near new condition, it is also utilized in this embodiment of the present invention as a means to create a strong metallurgical bond between the two metallic parts by closing off any gaps left after pressure has been applied to the mating surfaces as discussed in step 120 .
[0024] In an alternate embodiment of the present invention, the mating surfaces of the metallic parts to be joined have interlocking sections, so that the interlocking section from each metallic part can be inserted into a corresponding area in the interlocking section of the other metallic part when the metallic parts are brought into contact with each other. The interlocking sections on the metallic parts can be of any geometry or configuration as long as the interlocking section on each metallic part can be inserted into a corresponding area in the interlocking section of the other metallic part, thereby facilitating the metallic parts to snugly fit into each other. For example, the interlocking sections of each metallic part can have the same geometry or configuration, such as an alternating series of rectangular raised areas and grooves, where the rectangular raised areas of one metallic part can be inserted into the corresponding groove on the other metallic part. The interlocking section of each metallic part may have a different geometry or configuration, but their respective interlocking section form a mating pair. For example, the first metallic part has an interlocking section comprising a cylindrical raised area while the second metallic part has an interlocking section comprising a recessed area configured to receive the cylindrical raised area of the first metallic part.
[0025] The process 100 in this alternate embodiment remains similar, except that the positioning step 120 may require a more precise alignment of the metallic parts based on the geometry or configuration of the interlocking sections as described above. The precise alignment of the metallic parts should occur before pressure is applied. Once properly aligned, the interlocking sections of the metallic parts should be snugly fitted into each other, so that the metallic parts cannot be easily separated from each other. After pressure has been applied, there should be even fewer, if any, spaces between the metallic parts because of the tighter fit of the interlocking sections and the applied pressure, and the metallic parts should be difficult to separate at this point.
[0026] Any means known in the art may be used to create a tight fit between the interlocking sections after they have been precisely aligned into each other. In one embodiment, shrink-fitting is used, in which the metallic parts are immersed in a low temperature dry ice solvent or liquid nitrogen. During this cold immersion, the metallic parts contract, which allows the interlocking sections to fit into each other. The fit between the interlocking sections become very snug after the metallic parts are warmed to room temperature and allowed to expand.
[0027] FIG. 2 is a flowchart showing a method according to another embodiment of the present invention. The process 200 is used to repair superalloy components. In step 210 , the damaged portion of a work piece is replaced with a superalloy part. It should be appreciated that the work piece is made of a superalloy as well. The damaged portion can be removed by any means known in the art, and the removal of the damaged portion should be done carefully without exacerbating the condition of the remaining portion of the work piece. To ensure the best possible repair, the superalloy part used to replace the damaged portion should be comparable to the size and shape of the damaged portion, and the same type of superalloy should be used.
[0028] Next, in step 220 , the work piece and the superalloy part are prepared to reduce the amount of oxide on the surfaces to be joined and to clean these surfaces. A clean and oxide-free surface facilitates the eventual formation of a strong metallurgical bond. As described earlier, any means known by one of skill in the art can be used to prepare these surfaces. Similar to step 110 , the preparation of these surfaces is preferably achieved by a combination of surface grinding, grit-blasting, grinding/polishing, or fluoride ion cleaning (FIC). After these surfaces have been prepared, the work piece and superalloy part should be handled carefully, so that their surfaces do not get inadvertently contaminated, damaged or oxidized. It is also advisable to process the work piece and superalloy part shortly after this step 220 .
[0029] In step 230 , the work piece and superalloy part are positioned together, so that their respective prepared surfaces are brought into physical contact with each other, thereby creating mating surfaces for a joint to be formed. In a repair process 200 , the mating surface on the work piece generally comes from the area where the damaged portion was removed. In this embodiment, it should be appreciated that the mating surface from the superalloy part should fit over the mating surface of the work piece, especially since the superalloy part is comparable to the size and shape of the damaged portion. The mating surfaces cannot be randomly placed against each other, but they need to be positioned such that the work piece and the superalloy part can form a whole component smoothly.
[0030] Alternatively, the mating surfaces may have interlocking sections in a repair context. It may be worthwhile to create interlocking sections on the work piece and superalloy part if, for example, removal of the damaged portion created a surface that is difficult to mate a replacement piece to. The geometry and configuration of the interlocking sections may be influenced by the existing condition of the surface after the damaged portion has been removed, such as creating a more symmetrical pattern out of jagged protrusions from the work piece surface. When using interlocking sections on the mating surfaces, precise alignment of the work piece and the superalloy part is required to position the interlocking sections so that they fit into the corresponding area on the other mating surface, as described in the previous embodiments associated with the joining process 100 . Shrink-fitting may be used to create a very snug fit between the interlocking sections, as described before.
[0031] Just as in the other embodiments, any means known in the art can be used to bring these mating surfaces together during step 230 . After the mating surfaces are in place, pressure is applied to the work piece and superalloy part to provide intimate contact between the mating surfaces, closing off any gaps that may be present. As noted before, any means known in the art can be used to apply pressure, as long as pressure can be applied in a controlled manner so that the work piece and superalloy part do not get inadvertently damaged.
[0032] Subsequently in step 240 , the outer edges along the joint is sealed, to keep out any contamination or fluid leakage into the joint. Similar to step 130 , a seal weld is the preferred means to seal off the outer edges of the joint, although any other suitable means can be used, such as using a high temperature wax, as long as the sealing media or method provides a seal that can withstand the high temperature and pressure conditions associated with HIP.
[0033] In step 250 , the joined work piece and superalloy part undergo HIP. As mentioned earlier, the operational pressure range of HIP is generally 100 to 200 MPa. The operational temperature ranges of HIP can be within 50% to 80% of the materials' melting temperature. HIP serves the same purpose here as in step 140 . HIP not only re-conditions the micro-structure of the materials involved, which fortifies the materials' underlying strength, but also facilitates the formation of a strong metallurgical bond between the work piece and the superalloy part by closing off any gaps left after pressure has been applied to the mating surfaces.
[0034] It should be appreciated that the above embodiments also provide an improved method to enable the joining of superalloy metallic parts to repair hot section turbine components beyond the lower stress regions of the components. Repairs are no longer limited to the lower stress regions of the airfoil because welding with low strength weld fillers to create a weld joint has been eliminated. Instead, the joint area of the superalloy metallic parts are “fused” together via an application of pressure, the sealing of the joint's edges, and HIP, thereby creating a superior metallurgical bond suitable to withstand all stress loads. This improved method for repair offers great promise to save on turbine replacement costs by enabling more repairs to occur along the entire hot section turbine components.
[0035] While the foregoing description and drawing represent various embodiments of the present invention, it should be appreciated that the foregoing description should not be deemed limiting since additions, variations, modification, and substitutions may be made without departing from the spirit and scope of the present invention. It will be clear to one of skill in the art that the present invention may be embodied in other forms, structures, arrangements, proportions and using other elements, materials and components. For example, although the method has been described in terms of joining superalloy metallic parts, the method can be adapted for use with other types of steel or metals. The present disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims and not limited to the foregoing description.
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Accordingly, the present invention provides a method for joining metallic members, which can be used to join component sub-assemblies. Further, the present invention provides a method for repairing a component by replacing a damaged portion and re-inserting a replacement section. In general, the present invention provides in one embodiment a method for joining metallic members comprising: preparing a surface of a first metallic member, thereby providing an oxide-free surface; preparing a surface of a second metallic member, thereby providing an oxide-free surface; applying pressure to the first and second metallic members, thereby forcing the surface of the first metallic member and the surface of the second metallic member together and forming a joint area; sealing an outer edge of the joint area; and subjecting the members to a hot isostatic process operation.
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The present invention relates to a method and apparatus for supplying fibers to the inner wall of a spinning rotor of an open-end spinning machine whereby fibers resolved from a sliver are oriented and transported by an air current.
BACKGROUND OF THE INVENTION
1. Field of the Invention
It is important to stretch fibers resolved from a sliver and to orient and maintain the stretched fibers in parallelized condition as they are transported from a resolving device to a fiber collection surface of a spinning rotor. The most effective means of transporting such fibers utilized heretofore has been by an accelerated air stream passing through a fiber feed tube extending from the resolving device to the fiber-collection surface. However, intermolecular friction and friction between the air and the walls of the feed channel through which the air flows create shear stress in the air stream which results in turbulence. Consequently, fibers are frequently improperly and randomly oriented when they reach the spinning rotor, so that the quality and consistency of yarn spun in the rotor has suffered.
On the other hand, in the region in which the air stream contacts the rigid walls of a feed tube, the molecular random or mixing motion is damped by friction with the tube walls so that a boundary layer of laminar flow results. However, at locations spaced from the tube walls, the damping effect of the wall decreases and the internal friction of the air molecules again creates conditions such that turbulence is predominant. Again, fibers carried by the air stream are effected by such turbulence so that they cannot be maintained in a desired consistently oriented, generally parallel condition.
2. Prior Art
A variety of feed tubes for transporting fibers from one location to another are known. The following prior art is the most relevant to the present invention. The prior art disclosures do not recognize or solve the turbulence problems overcome by the present invention; and feed tubes constructed in accordance with those disclosures do produce turbulent airflow conditions, or are not suitable for parallelizing fibers, or otherwise are incapable of orienting fibers satisfactorily to cooperate with an open-end spinning machine for forming yarn of consistent quality and desired characteristics.
Prior apparatus for accelerating an air current for transporting fiber is disclosed in DT-AS 1,510,741 which includes a frustoconical or otherwise reduced cross-sectional area feed tube. While the fibers being transported to the spinning rotor may be oriented as desired initially, the aforesaid conditions of turbulence prevail and prevent controlled orientation of the fibers at the point of deposit on the fiber collection surface of a spinning rotor.
Prior feed tubes having a conic portion followed by a cylindrical portion have been proposed. One such feed tube arrangement is disclosed in DT-OS 1,922,743. In this case, the conic portion functions as a condenser. The cylindrical portion merely forms a passage through the spinning rotor housing cover and cooperates with the conic portion to hold the cover firmly in place. Another feed tube is shown in DT-OS 1,925,999, but the degree of conicity of the conic portion is too slight to impart sufficient acceleration to the fibers for effecting a consistent fiber lay. The fibers are accelerated by an auxiliary vacuum air current which acts on the fibers in the region between the conic and cylindrical portion. The effect of this sudden air current is to create substantial turbulence whereby the lay of the fibers is undesirably disturbed.
Another variation in feed tubes is disclosed in U.S. Pat. No. 3,521,440 in which the cross-sectional shape of a tube is varied along its length without changing the cross-sectional area of the tube. This type of tube serves the function of urging fibers together to form a concentrated fiber stream and is used for fibers delivered by a drafting system rolling mill. In this apparatus, there is no acceleration of the air which accompanies the fiber stream.
SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide a method and apparatus which produces acceleration of the proper degree of transport and orientation of resolved fibers by a fluid or air medium.
It is a companion object to eliminate the turbulence which has heretofore prevented deposition of fibers on the spinning rotor inner wall with consistent preferred orientation.
The foregoing objects are accomplished in accordance with the present invention by first subjecting fibers resolved from a sliver to a rapidly accelerating air current, by immediately thereafter subjecting such fibers to an air current flowing at substantially constant velocity and, finally, by subjecting such fibers to the rotational forces of the rotating inner wall of the spinning rotor. The intermolecular friction of the fluid medium is reduced and turbulence is substantially diminished by the sequential process of accelerating the fluid current and then maintaining such current at a velocity approaching constancy. By such method the fibers supplied to such current are also stabilized so that the fibers are transported in stretched and parallelized condition to the spinning rotor inner wall.
Apparatus for carrying out this procedure includes a feed tube having a frustoconical first section tapering to a cylindrical second section. The infeed orifice of the conic portion has a cross-sectional area 4 to 20 times the area of the cylindrical portion. The diameter of the cylindrical portion is between one-tenth and one-twenty-fifth of the total length of the feed tube, and the length of the cylindrical portion is from 1/2 to 3 times the length of the conic portion. In a feed tube constructed within these proportions, a stream of air passing through the tube first strongly accelerates the fibers delivered by a sliver-opening roller. Because of their mass, the fibers have sufficient inertia so that they cannot be accelerated as quickly as the air. Consequently, the conic portion must have sufficient length and conicity to provide an adequate period to accelerate the fibers to the velocity of the air stream in the cylindrical portion of the feed tube. The internal friction of the air is substantially reduced in the tube cylindrical portion so that there is little turbulence in this portion of the fiber transport. Consequently, the lay of the fibers is improved and stabilized.
In order to prevent a source of turbulence at the outfeed orifice of the feed tube, the center of the orifice should be spaced from the spinning rotor inner wall a distance between one-tenth and four-tenths of the inside diameter of the spinning rotor at the location of the outfeed end of the feed tube. The fiber can be guided even more advantageously from the substantially constant velocity of the feed tube into the angular velocity of the spinning rotor boundary layer by providing a notch in the outfeed end of the feed tube adjacent to the rotor inner wall, the length of which notch extends in the circumferential direction of the spinning rotor.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a section through a resolving device and spinning rotor taken axially of the rotor and showing the fiber feed arrangement of the present invention.
FIG. 2 is an axial section through a feed tube in accordance with the present invention.
FIG. 3 is a fragmentary section similar to FIG. 1 showing a modified feed tube.
FIG. 4 is a diametral section through the spinning rotor showing the outfeed end of the feed tube with parts broken away.
FIG. 5 is a diametral section similar to FIG. 4, but showing the modified feed tube of FIG. 3.
DETAILED DESCRIPTION
The open-end spinning device shown in FIG. 1 conventionally includes a resolving device 1 for resolving a fiber sliver into individual fibers. Such fibers are transported by a feed tube 2 to the spinning rotor 3. Spinning rotor 3 is enclosed by a housing 30 closed by a cover 31. The cover also carries a draw-off tube (not shown) through which spun thread is drawn off by a conventional take-up device. The subpressure required for spinning is created either by the rotation of the spinning rotor itself or by evacuating means common to a number of spinning rotors. The form of resolving device shown by way of illustration includes a rapidly rotating opening roller 11 carried in a housing 10. The roller-receiving hollow of housing 10 forms with the roller periphery a channel 12 for guiding the fibers to feed tube 2. The feed tube has a frustoconical infeed section 20 which is joined at 23 directly to a cylindrical outfeed section 21. The larger end of the conical section defines an infeed orifice 22 and the end of the cylindrical section remote from the conical section defines an outfeed orifice 24. A fluid medium, which is preferably air, transports the fibers through feed tube 2.
In accordance with the present invention, the conical section is to effect acceleration of the air to the desired end velocity, for which purpose a very rapid acceleration is required. The degree of acceleration between the resolving device 1 and the feed tube junction 23 should be in the range of 6.6 × 10 5 cm/sec. and 1.8 × 10 6 cm/sec 2 and the degree of acceleration between the junction 23 and the outfeed orifice 24 should be in the range of 2 × 10 6 cm/sec 2 and 7.8 × 10 5 cm/sec 2 . In order to produce the necessary acceleration, the infeed orifice 22 has a cross-sectional area four to twenty times greater than the cross-sectional area of the tubular passage through the cylindrical section 21. The cross-sectional area of the cylindrical section is established in the conventional manner. In the cylindrical section 21, the air assumes a constant velocity.
While fibers carried by the feed tube air stream are accelerated by frictional engagement with the air stream molecules, such fibers receive a somewhat smaller acceleration than the air stream acceleration resulting from the taper of the passage through the conic section because of their inertia. The fiber speed, therefore, is less than the air speed at the junction 23 between the conic section 20 and the cylindrical section 21. Because of intermolecular friction in the accelerating air stream, turbulence is created which disturbs the parallelized lay of the fibers which would result from streamline air flow. Consequently, in order to postaccelerate the fibers to improve the lay of the fibers in the rotor 3 in accordance with the present invention, the cylindrical section 21 is joined directly to the smaller end of the frustoconical section 20. As the air assumes constant velocity in the cylindrical section, intermolecular friction is reduced, and, consequently, there is little turbulence in this feed tube portion. Because the fibers do not achieve the same speed as the air stream in the conic accelerating section 20, the fibers are additionally accelerated in the constant air speed cylindrical section whereby they are further straightened and parallelized, and such orientation is maintained by the substantially turbulent-free air stream throughout the cylindrical section.
It has been determined in accordance with the invention that the length a of the cylindrical section 21 shown in FIG. 2 must be between one-half and three times the length b of the conic section 20. Experiments have shown that the fibers cannot be postaccelerated to attain substantially the speed of the air in the cylindrical section if it is shorter than one-half the length of the conic section. Furthermore, it has been determined that, if the cylindrical section is longer than three times the length of the conic section, the effect of the friction between the tube walls and the air predominates and generates turbulence in the air stream.
The total length L of the feed tube 2 has been determined in accordance with the present invention to be in the range of ten to twenty-five times the internal diameter d of the cylindrical section 21. Within this range the fibers can be accelerated to the desired end speed while permitting good parallelization of the fibers and stabilization of the fiber lay to be achieved in the cylindrical section 21. A typical exemple of a preferred type of feed tube for spinning of short staple fibers has the following dimensions:
Length a of the cylindrical section 21 : 40 mm
Length b of the conic section 20 : 40 mm
Total length L : 80 mm
Area of infeed orifice 22 : 154 mm 2
Area of junction 23 : 33 mm 2
After resolution of a fiber sliver, the individual fibers are first exposed to the effect of a heavily accelerated air stream in the conic section 20 of the feed tube 2. Immediately thereafter the fibers are subjected to an air stream flowing at substantially constant speed through the cylindrical section 21. As the fibers leave the outfeed orifice 24, they are subjected to the effect of the rotating inner wall 32 of the spinning chamber in rotor 33 and the rotating air boundary layer, the speed of which boundary layer corresponds directly, or very closely, to the circumferential speed of the spinning rotor inner wall 32. The angular velocity of the rotating air in the spinning rotor 3 decreases radially inwardly from the rotor wall 32 because, on the one hand, the radius decreases and, on the other hand, because the frictional effect of the boundary layer decreases.
If the feed tube opens into a region in which the rotating boundary layer effects an air speed greater than the speed of the air discharged from the feed tube 2, then an air shear corner develops at the outfeed end of the feed tube and air vortices are created. Such vortices work into the end of the feed tube and cause the exiting fibers to whirl around at the outfeed orifice 24. In order to avoid this vortex effect, it has been determined that the radial distance c from the rotor inner wall 32 to the center of the outfeed orifice 24 (FIG. 4) should be in the range of one-fortieth to one-tenth of the diameter D of the rotor diametral plane on which the orifice center lies. By such location of the feed tube outfeed orifice 24 the rotating air flow is not disturbed.
Diametrically opposite sides of the outfeed end of tube 21 along a diameter substantially aligned with the axis of the spinning rotor 3 can be disposed closer to the spinning rotor inner wall 32 in order to maintain the fibers under control of the linear flow of the feed tube air stream for a greater distance along the rotor inner wall 32 axially of the rotor. This can be done in accordance with the present invention by providing a notch 25 in that side of the rim of orifice 24 adjacent to the spinning rotor wall 32. The length of such notch extends in a direction substantially circumferentially of the spinning rotor 3. Therefore, as shown in FIG. 3, the outfeed end of the feed tube 2, has projections 26 and 27 on opposite sides of notch 25 which are located at opposite ends of a chord of orifice 24 extending substantially parallel to the axis of spinning rotor 3. Such a notched feed tube end can be used to improve the performance of other forms of feed tubes used in combination with spinning rotors of openend spinning machines and is not restricted only to use with the feed tube construction disclosed herein.
By use of the method and apparatus of the present invention, fibers are guided in their path from the resolving device 1 under the control of the air current in such a manner that they are deposited in stretched and parallelized condition onto the spinning rotor inner wall 32. At the same time the apparatus for providing such controlled fiber transport is simple in construction. The form of cover 31 is not significant for purposes of the present invention; thus the invention can be used in spinning devices in which the cover projects farther into the spinning rotor cavity than is shown in FIG. 1, and the outfeed end of tube 2 can be just inside the cover, as shown, or can project farther into the rotor cavity.
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Fibers are carried to a spinning rotor from a fiber-resolving device by a translational fluid medium, such as air, which is first accelerated to orient the fibers. Carrier fluid next is maintained at constant speed and laminar flow to deliver the oriented fibers to a rotating laminar fluid in the region adjacent to the inner wall of the spinning rotor. The acceleration and velocity of the translational fluid is effected by a feed tube having a frustoconical infeed section, tapered toward a cylindrical outfeed section.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to a composition and method for insulating roadways to prevent icing and, more particularly, to a method for incorporating foam plastic pellets into the final surface layer, or wearing course, of a paved road.
[0002] It is well known that roads, bridges, expressways, and overpasses can ice over in periods of low temperature, resulting in unsafe driving conditions. Bridges and overpasses are particularly susceptible to this problem because they have a higher content of cold-conducting metal in their structures and more of their surface area is exposed to wind and low temperatures than that of typical roadways. The tendency of bridges and overpasses to ice over earlier than the approach pavement can result in severe accidents when unsuspecting motorists encounter an iced-over bridge after traveling on a relatively safe roadway.
[0003] Numerous methods have been employed in an attempt to reduce the danger created by this phenomenon. Some methods, such as the application of salt or sand to a roadway, are implemented shortly before or after the structure freezes in an attempt to melt the ice that forms, or to provide better traction for vehicles driving on the ice. The application of sand and deicing materials, such as salt, typically transpires after icing has occurred, which is often too late for the first motorists to drive on the roadway. In addition, the necessity of repeated applications and the corrosive effect many of these materials have on the road surface result in high maintenance costs. Furthermore, these materials can be harmful to drivers and their vehicles. The materials often cause the formation of rust on vehicles, reducing their value, and the presence of loose debris on the roadway is dangerous to pedestrians and passengers, as well as harmful to the vehicles themselves.
[0004] Other attempts at a solution focus on prevention through construction of a roadway less susceptible to icing. For example, road builders have been known to apply thick layers of gravel or other non-frost susceptible materials as a base course prior to laying down the surface pavement. The gravel layers are designed to serve as a frost barrier. The disadvantage of this method is that thick layers of the material are required to achieve the desired effect. This results in very high material, transport, and labor costs. Furthermore, it is not always feasible to lay thick layers of gravel down on bridges and overpasses.
[0005] Builders have also been known to add a layer of high-grade insulating material, such as boards of plastic foam or cork, prior to applying the surface layer of the road. The foam insulation is superior to gravel because a thinner layer of material can provide the same insulative effect. Foam plastic—created from any suitable expanded plastic polymer, such as polystyrene, polyethylene, or polyurethane—is comprised of about 5% plastic polymer and 95% air. Because air is an excellent insulator, a structure containing a sufficient amount of foam plastic will be less likely to freeze. Plastic foam's quality as an insulator is well known and can be seen in coffee cups, coolers, packaging materials, and wall insulation. However, when boards of plastic foam or other high-grade insulating material are used to form an insulative sub-layer, the material is fragile and difficult to work with. Typically, an additional layer of sand must be applied on top of the insulation material prior to the use of heavy road construction equipment or the fragile material will be crushed. The need to apply an additional layer of sand as well as the difficulty inherent in transporting and installing such lightweight and fragile material make this an undesirable method.
[0006] A third method of road construction disclosed in the prior art involves the use of an insulating sub-layer comprised of foam plastic particles dispersed throughout cement. According to this method, an additional layer of traditional asphalt or concrete is applied on top of the insulating layer to serve as the wearing course. This method has the disadvantage of requiring the application of a final surface layer of concrete on top of the insulating layer of concrete. This leads to increased labor costs because road builders must create at least two different concrete mixtures and are required to apply multiple layers.
[0007] While previous methods for insulating roadways have included layers of insulating material below the surface pavement, none have disclosed incorporating insulation material into the wearing course of a finished roadway. This is likely due to concerns about the insulating material's effect on the strength and durability of the surface pavement. However, in addition to reducing the likelihood of icing on a roadway, incorporating foam plastic into a road's wearing course rather than a sub-layer provides numerous benefits. One benefit would be lower labor costs. Because the insulating layer is the wearing course, road builders are not required to mix and spread more than one type of concrete or asphalt. A second benefit is the low cost of foam plastic itself. Foam typically costs less than the same volume of aggregate used in traditional roadways. Other benefits can be expected to arise from plastic foam's unique characteristics. For example, it is likely that a wearing course containing foam plastic will exhibit less road noise than a typical pavement and will be less impacted by environmental factors, such as extreme heat.
[0008] What is needed, therefore, is a composition and a method, which is not overly expensive or burdensome, that reduces roadway icing by incorporating insulation material into a pavement's wearing course.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention solves the foregoing problem by providing a wearing course for a paved road that includes insulative foam plastic in its structure and further providing a method for constructing said wearing course.
[0010] The wearing course in the present invention comprises an aggregate composite material, such as portland cement concrete or asphalt concrete, and a quantity of expanded plastic polymer, commonly referred to as “foam plastic,” which functions as insulation. The insulative wearing course serves as a paved roadway's trafficked surface layer and is applied directly to a prepared subgrade or base course. The insulative wearing course may also serve as the surface layer for bridges, expressways, and overpasses by applying it directly to the deck of the structure or a prepared base course.
[0011] Despite previous concerns about the insulating material's effect on the strength and durability of the surface pavement, by following the method taught in the present invention, no change is expected in the durability of the roadway's wearing course. This is due to the inherent strength of confined air as well as the energy absorption characteristics of plastic foam.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. The same reference numerals are employed to designate like parts in both Figures.
[0013] In the drawings:
[0014] FIG. 1 shows a cross-sectional elevation view of a roadway pavement constructed according to one embodiment of the present invention.
[0015] FIG. 2 shows a perspective view in partial cross-section of a bridge or overpass constructed according to one embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] FIG. 1 shows one embodiment of the present invention. The ground is leveled and compacted to form a suitable subgrade 2 according to techniques well known in the art. A base course 4 , preferably comprised of larger-grade mineral aggregate 6 , is spread and compacted on top of the subgrade 2 . Alternatively, the base course 4 may be omitted. An insulative wearing course 8 of aggregate composite material, described in more detail below, is fabricated and applied as a final pavement layer.
[0017] The insulative wearing course 8 employs expanded plastic polymer pellets 10 as insulation. In one embodiment, the foam plastic pellets 10 are roughly spherical with a diameter of approximately ¼ inch and are made of polystyrene foam. Polystyrene is preferred because it is inexpensive and widely available. Spherical pellets are preferred because a sphere provides the maximum amount of surface area by volume and, therefore, the most insulation for its size. Foam pellets approximately ¼ inch in diameter will generally work well because ¼ inch is a typical size for aggregate and pellets that size will integrate well with many composite material mixtures. However, the size of the foam pellets may vary and may depend upon such factors as the type of roadway being constructed, as well as the size and quantity of other aggregate added to the composite material mixture.
[0018] The insulative wearing course 8 may be in the form of one of numerous types of pavements. One embodiment of the insulative wearing course 8 is an asphalt concrete pavement. Foam plastic pellets 10 are added to a mixture of mineral aggregate 12 and bituminous binder in an amount approximately equal to 25% to 30% of the total volume of the mixture. The amount and quality of mineral aggregate 12 added will vary depending on the particular circumstances, and a road builder with ordinary skill in the art will be able to determine the qualities best suited for obtaining a homogenous mixture. Preferably the mixture is added to the hopper of a hot mix asphalt paving machine. The asphalt concrete mixture is then applied to the desired substrate, either a base course 4 , a prepared subgrade 2 as in FIG. 1 , or a deck 26 as in FIG. 2 . The asphalt concrete mixture may be applied using the asphalt paving machine and compressed with a roller in a manner familiar to those skilled in the art. Alternatively, a mixture of the foam plastic pellets 10 and mineral aggregate 12 is applied directly to the structure. The bituminous binder may then be applied on top of the aggregate and compressed with a roller.
[0019] A second embodiment of the insulative wearing course 8 is a cement concrete pavement. Foam plastic pellets 10 are added to a mixture of mineral aggregate 12 and portland cement binder in an amount approximately equal to 25% to 30% of the total volume of the mixture. Alternatively, the foam plastic pellets 10 may be added to the drum of a concrete mixer truck containing a cement concrete mixture. Adding the foam plastic pellets 10 to the aggregate composite material mixture prior to pouring the pavement is not essential, but it is preferred, as loose plastic foam pellets may be difficult to work with in inclement weather. As with an asphalt concrete pavement, the amount and quality of mineral aggregate 12 added will vary depending on the particular circumstances and a road builder with ordinary skill in the art will be able to determine the qualities best suited for obtaining a homogenous mixture. The cement concrete mixture is then poured onto the desired substrate, either a base course 4 , a prepared subgrade 2 as in FIG. 1 , or a deck 26 as in FIG. 2 . A paving machine is used to facilitate the paving process.
[0020] A third embodiment of the insulative wearing course 8 is a pavement constructed from prefabricated concrete slabs. Cement concrete is mixed according to the cement concrete pavement embodiment described above. The cement concrete mixture containing the foam plastic pellets 10 is poured into a form designed for concrete pavement slabs of dimensions well known in the art. After they have cured, the prefabricated concrete slabs are transported and applied to the desired substrate, either a base course 4 , a prepared subgrade 2 as in FIG. 1 , or a deck 26 as in FIG. 2 .
[0021] An alternative embodiment of the present invention is illustrated in FIG. 2 . A bridge or overpass is constructed according to traditional methods well known in the art. Preferably, steel reinforced concrete girders 20 are installed longitudinally between supports 22 attached to reinforced concrete piles 24 of the desired height. The concrete girders 20 support the deck 26 of the roadway. Concrete barrier walls 28 or guard rails should run longitudinally along the structure for safety. A base course 4 , preferably comprised of larger-grade mineral aggregate 6 , is spread and compacted on top of the deck 26 . Alternatively, the base course 4 may be omitted. As in the previous embodiment, an insulative wearing course 8 , described in more detail above, is fabricated and applied as a final pavement layer.
[0022] The foregoing description of the preferred embodiments of the present invention has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above description. The scope of the invention is to be defined only by the claims appended hereto.
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A method and composition of matter used to reduce icing of roads, bridges, and overpasses where the wearing course of the paved structure contains expanded plastic polymer. The expanded plastic polymer functions as insulation and reduces the likelihood that the wearing course of the structure will freeze over, thereby lessening the danger drivers face during colder months.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the storage of ammonia in a solid form using metal ammine complexes and delivery there from. The invention also relates to the use of ammonia stored in a solid form as the reducing agent in selective catalytic reduction (SCR) of NO x in exhaust gases from combustion processes, to methods for producing such complexes and to an ammonia delivery device comprising such complexes.
[0003] 2. Description of the Related Art
[0004] Current environmental regulations necessitate the use of catalysts in the exhaust gas from automotive vehicles, boilers and furnaces for control of NO x emission leaving the system. Particularly, vehicles equipped with diesel engines or other lean burn engines offer the benefit of improved fuel economy, but suffer from the drawback of increased formation of NO x being noxious and which must be eliminated from the exhaust gas. However, catalytic reduction of NO x using conventional so-called three-way exhaust catalysts for automobiles is impossible because of the high content of oxygen in the exhaust gas. Instead, selective catalytic reduction (SCR) has proven useful for achieving the required low levels of NO x in the exhaust gas both in stationary and mobile units. In such systems NO x is continuously removed from the exhaust gas by injection of a reducing agent into the exhaust gas prior to entering an SCR catalyst capable of achieving a high conversion of NO x . So far, ammonia has proven to be the most efficient reducing agent, which is usually introduced into the exhaust gas by controlled injection of gaseous ammonia, aqueous ammonia or aqueous urea. In all cases, the amount of reducing agent being dosed has to be very precisely controlled. Injection of a too large amount of reducing agent will cause emission of ammonia with the exhaust gas whereas injection of a too small amount of reducing agent causes a less than optimum conversion of NO x .
[0005] In many mobile units powered by combustion engines, the preferred technical solution is to use an aqueous solution of urea as the reducing agent since in this way potential hazards or safety issues relating to the transport and handling of liquid ammonia in high pressure containers are eliminated. However, there are several disadvantages related to the use of aqueous urea as the reducing agent. First of all, the use of urea solutions requires the carrying of a relatively large volume in order to provide sufficient amounts of ammonia to allow a vehicle to drive e.g. about 20,000 kilometres without having to substitute or refill the source of ammonia. In typical systems, an aqueous solution comprising about 30 wt % of urea is preferred meaning that about 70 wt % of the content of a container holding the urea solution is used only to transport water. During the decomposition, one molecule of urea forms two molecules of NH 3 and one molecule of CO 2 and thus, ammonia only constitutes roughly 50 wt % of the weight of the urea molecule and hence, the concentration of ammonia of the reducing agent is very low. Similar concentrations of ammonia can be achieved using aqueous solutions of ammonia as reducing agents. Furthermore, when using solutions, specially designed spray nozzles combined with a precision liquid pump are required to ensure that a) the aqueous urea is delivered to the exhaust system at a desired (and dynamically changing) flow rate and b) the aqueous urea is efficiently dispersed in the gas phase before entering the catalyst. Finally, the aqueous solutions might freeze in cold weather conditions (below minus 11° C.), or the urea solution may simply form precipitates, which will block the dosing system, e.g. the nozzle. Altogether, these difficulties may limit the possibilities of using SCR technology in abatement of pollution from NO x , particularly in connection with mobile units.
[0006] Transporting ammonia as a pressurized liquid is hazardous as the container may burst or a valve or tube might break in an accident giving a discharge of poisonous/lethal gaseous ammonia. In the case of the use of a solid storage medium containing absorbed/adsorbed ammonia, the safety issues are much less critical since a small amount of heat is required to release the ammonia from the storage medium.
[0007] International Patent Publication No. WO 99/01205 discloses a method and a device for selective catalytic NOx reduction in waste gases containing oxygen, using ammonia and a reduction catalyst. According to the method, gaseous ammonia is provided by heating a solid storage medium comprising one or more salts, especially a chloride and/or sulphate of one or more cations selected from alkaline earth metals, and/or one or more transition metals, preferably Mn, Fe, Co, Ni, Cu, and/or Zn, said storage medium being introduced into a container. In the preferred embodiments of WO 99/01205 the cation is Ca 2+ or Sr 2+ . The inventive method and device are stated to be particularly suitable for use in automobiles.
[0008] However, the use of the ammonia storage media known from WO 99/01205 suffers from various draw-backs hampering a wide-spread use in the automotive industry. The vapour pressure of ammonia above a solid salt phase is e.g. about 1 bar at room temperature and atmospheric pressure for calcium octa ammine chloride and strontium octa ammine chloride complexes rendering the use somewhat complicated due to the high pressures that must be taken into account in view of the toxicity of ammonia. Having such a high partial pressure of ammonia, the handling and transportation of the saturated storage material is still difficult and also dangerous. Still further, the use of granulated storage materials—stated as preferred embodiments in WO 99/01205—requires measures for preventing the storage material from leaving the container during use in moving vehicles. Furthermore, a granulated material will have a considerable void between the granules which will drastically reduce the bulk density of the storage material by a factor 1.5-2.
[0009] It has now been found that these drawbacks may be overcome using a magnesium salt complex according to the present invention providing a compact, light-weight, cheap and more safe storage for ammonia having a very low vapour pressure of ammonia below 0.1 bar at room temperature to be used in the automotive industry.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg.
[0011] In a second aspect the invention relates to a method of producing a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, said method comprising the steps of
1) providing the solid salt,
2) saturating the salt with ammonia, and
3) compressing the ammonia salt complex.
[0012] In a third aspect the invention relates to a method for selective catalytic NO x reduction in waste gases containing oxygen, using ammonia and a reduction catalyst wherein gaseous ammonia is provided by heating a solid storage medium comprising one or more ionic ammonia absorbing salts of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and transition metals such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions such as chloride or sulphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg and wherein the release rate of ammonia is controlled in consideration of the content of NO x in the waste gases.
[0013] In a fourth aspect the invention relates to the use of a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and transition metals such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions such as chloride or sulphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg as a source of ammonia as the reducing agent in selective catalytic reduction (SCR) of NO x in exhaust gases from combustion processes.
[0014] In a fifth aspect the invention relates to an ammonia delivery device comprising a container comprising
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg, said container being provided with one or more closable outlet opening(s) connected to a pipe and further being provided with means for heating the container and the ammonia absorbing salt for release of gaseous ammonia.
[0015] In a sixth aspect the invention relates to the use of an ammonia delivery device comprising a container comprising
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg, said container being provided with one or one or more closable outlet opening(s) connected to a pipe and further being provided with means for heating the container and the ammonia absorbing salt for release of gaseous ammonia as a source for ammonia in selective catalytic reduction of NO x in exhaust gases from combustion processes.
[0016] In a seventh aspect the invention relates to a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkali metals, alkaline earth metals, and transition metals such as Li, Na, K, Cs, Mg, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn or combinations thereof such as NaAl, KAI, K 2 Zn, CsCu, or K 2 Fe, X is one or more anions selected from fluoride, chloride, bromide, iodide, nitrate, thiocyanate, sulphate, molybdate, and phosphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, said storage and delivery material having a density of 0.9 to 1.3 g/cm 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention is disclosed more in detail with reference to the drawings in which
[0018] FIG. 1 shows a photograph of an ammonia delivery device of the invention,
[0019] FIG. 2 shows schematically a top view of the location of thermocouples in the device of FIG. 1 ,
[0020] FIG. 3 shows a diagram of the experimental setup,
[0021] FIG. 4 shows a graphical representation of the desorption of the ammonia,
[0022] FIG. 5 is a plot of the buffer pressure during desorption of the ammonia,
[0023] FIG. 6 shows the pressure and flow in a single pressure oscillation period during desorption,
[0024] FIG. 7 schematically shows a device for compression of an ammonia delivery material,
[0025] FIG. 8 schematically shows an embodiment of an ammonia delivery device of the invention,
[0026] FIG. 9 schematically shows another embodiment of an ammonia delivery device of the invention,
[0027] and FIG. 10 shows an equilibrium phase-diagram for the MgCl 2 —NH 3 system.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0028] The present invention is related to the use of metal-ammine salts as safe and efficient solid storage media for storage and controlled delivery of ammonia, which in turn is used as the reduction agent in selective catalytic. reduction to reduce NO x emissions, especially from automotive vehicles, boilers and furnaces.
[0029] The present invention relates to a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg.
[0030] Suitable anions to be used according to the present invention may be selected from fluoride, chloride, bromide, iodide, nitrate, thiocyanate, sulphate, molybdate, and phosphate ions. The anion is preferably the chloride.
[0031] A preferred solid ammonia delivery material according to the invention is Mg(NH 3 ) 6 Cl 2 .
[0032] It has been found that although Mg(NH 3 ) 6 Cl 2 has a very low partial pressure of ammonia above a salt phase, below 0.1 bar at room temperature, it is very suitable for use as a source of ammonia in SCR technology for abatement of pollution from NO x .
[0033] A solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions selected from chloride and sulphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, and the use thereof are also considered aspects of the present invention.
[0034] An ammonia saturated material of the invention may be prepared by exposing the dry salt to gaseous ammonia in a manner known per se. The ammonia saturated delivery material as prepared is powdery and rather “fluffy” and difficult to handle or transport and may be—during transport or use—transformed into small particle fragments thereby potentially blocking the dosing system of a device or give rise to hazardous dust into the environment. Furthermore, the powder has a low bulk density.
[0035] In a preferred embodiment of the invention the solid delivery material has a density of 0.9 to 1.3 g/cm 3 , more preferred a density of 1.1 to 1.3 g/cm 3 giving a very high-density storage and delivery material.
[0036] The compacted material shows a very low release rate of ammonia at room temperature and atmospheric pressure and may be handled without special precautionary measures for protection against the action of ammonia. The compacted material can easily be handled during transport and during and after the final application.
[0037] It has surprisingly been found that a powdered ammonia delivery material of the present invention having a very low vapour pressure of ammonia at room temperature may be compacted to a very high density using several different methods for shaping of the material into a desired form and still be capable of delivery of ammonia at a sufficient rate to be suitable for use as a source of ammonia for a SCR reduction of NOx in e.g. automotive vehicles, boilers and furnaces. Such methods are e.g. pressing, extrusion, and injection moulding. In the case of pressing, a pressure might be applied in several different ways in a manner known per se. In one embodiment, the material is compressed to shapes like dense blocks or tablets by placing the saturated salt in a groove/dent/hole/pit in a metal block (e.g. in a cylindrical hole) and applying pressure to compress the material using a corresponding piston.
[0038] The saturated material is preferably compressed to a bulk density above 70%, more preferred above 80% and even more preferred above 85%, of the skeleton density. In a preferred embodiment the present invention is related to the compaction and shaping of the saturated ammonia delivery material.
[0039] When an ammine complex of a salt is compressed to such a high extent, desorption from such a compacted material would be expected to be extremely slow, mostly due to diffusion hindrance. In most dense materials desorption of ammonia would involve solid state diffusion which is known to be a slow process for virtually all materials. This has surprisingly been found not to be the case for the dense materials according to the present invention. It has been found that when ammonia desorbs, a progressing nano-porous structure is formed as the “reaction front” proceeds, leaving open paths for additional ammonia to leave from the central parts of the body of storage material. This is in contrast to e.g. classical heterogeneous catalysis where conversion of reactants is only possible, if reactants are able to diffuse into the catalyst pore structure and the products are able to diffuse out of the catalyst pore structure.
[0040] The metal-ammine salts constitute a solid storage medium for ammonia, which represent a safe, practical and compact option for storage and transportation of ammonia (a single-crystalline compound of Mg(NH 3 ) 6 Cl 2 has an ammonia density of 38 kmole NH 3 /m 3 , whereas that of liquid ammonia is only slightly higher (40 kmole NH 3 /m 3 )). Ammonia may be released from the metal ammine salt by heating the salt to temperatures in the range from 10° C., to the melting point of the metal salt ammine complex, preferably to a temperature from 100 to 700° C., more preferred to a temperature from 150 to 500° C.
[0041] During release of ammonia the metal-ammine salt of the formula M a (NH 3 ) n X z wherein M, X, a, n, and z has the meaning stated above, is gradually transformed into a salt of the formula M a (NH 3 ) m X z wherein 0≦m<n. When the desired amount of ammonia has been released, the resulting salt of formula M a (NH 3 ) m X z can usually be converted back into the salt of the formula M a (NH 3 ) n X z by treatment with a gas containing ammonia.
[0042] Anhydrous MgCl 2 absorbs up to six moles of NH 3 (Gmelins Handbuch, 1939; Liu, 2004) according to reactions 1 to 3:
[0000] MgCl 2 (s)+NH 3 (g) Mg(NH 3 )Cl 2 (s) (1)
[0000] Mg(NH 3 )Cl 2 (s)+NH 3 (g) Mg(NH 3 ) 2 Cl 2 (s) (2)
[0000] Mg(NH 3 ) 2 Cl 2 (s)+4NH 3 (g) Mg(NH 3 ) 6 Cl 2 (s) (3)
[0043] Typical ammonia contents of the metal ammine complexes are in the range of 20-60 wt %, and preferred complexes comprise above 30 wt % ammonia, more preferred above 40 wt % ammonia. The inexpensive compound Mg(NH 3 ) 6 Cl 2 contains 51.7 wt % ammonia.
[0044] The present invention offers ammonia storage at significantly higher densities (both on a volume and a weight basis) than both aqueous ammonia and aqueous urea. For several metal ammine salts it is possible to release all ammonia and then transform the resulting material back into the original metal ammine salt in a large number of cycles. Additionally, the ammonia is directly delivered into the exhaust pipe as a gas, which is an advantage in itself—both for the simplicity of the flow control system and for an efficient mixing of reducing agent, ammonia, in the exhaust gas—but it also eliminates possible difficulties related to blocking of the dosing system because of precipitation in the liquid-based system.
[0045] Some metal ammine complexes offer a further advantage in that the vapour pressure of ammonia above a solid salt phase is relatively low. It is preferred that the vapour pressure is below 0.1 bar at room temperature, preferably below 0.01 bar. Specifically for Mg(NH 3 ) 6 Cl 2 the vapour pressure is as low as 0.002 bar at room temperature and atmospheric pressure which in practice eliminates any noxious effect of the ammonia as the release of ammonia is as low or lower than the release from common cleaning materials containing ammonia.
[0046] For Mg(NH 3 ) 6 Cl 2 the partial pressure of ammonia at room temperature is 0.002 bar. Even though a partial pressure of ammonia of 0.002 bar at ambient temperature in itself could cause health problems, the compacted material according to the invention saturated with ammonia releases ammonia at a very slow rate at ambient temperature and an equilibrium pressure of 0.002 bar will only be obtained after a considerable span of time, even if the material is placed in a very confined space. However, when raising the temperature e.g. in the delivery device, a quite quick desorption of ammonia is observed as discussed above.
[0047] For mobile units, it is particularly useful to use an ammonia delivery device comprising a container containing the metal ammine complex as such a container may easily be separated from mobile unit and replaced by a fresh at suitable intervals. In preferred embodiments, the metal ammine containers are recycled and recharged with ammonia in a separate recharging unit.
[0048] Due to the slow release of ammonia in open atmosphere at ambient temperatures for the compressed materials of the present invention, the handling of the materials does not require extensive safety precautions and substitution of exhausted storage and delivery material with fresh material does not require an encapsulation of the material facilitating the handling as compared to the handling of the materials used in the methods of the state of the art.
[0049] In another aspect the invention relates to a method of producing a solid ammonia storage and delivery material comprising an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, said method comprising the steps of
1) providing the solid salt,
2) saturating the salt with ammonia, and
3) compressing the ammonia salt complex to a dense, shaped body.
[0050] In a preferred embodiment of the method of the invention, the ammonia salt complex is compressed to a density of 0.9 to 1.3 g/cm 3 , more preferred to a density of 1.1 to 1.3 g/cm 3
[0051] In a further aspect the invention relates to a method of selective catalytic NO x reduction in waste gases containing oxygen, using ammonia and a reduction catalyst wherein gaseous ammonia is provided by heating a solid storage and delivery medium comprising one or more ionic ammonia absorbing salts of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and transition metals such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg and wherein the release rate of ammonia is controlled in consideration of the content of NO x in the waste gases.
[0052] In a yet further aspect the invention relates to the use of a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and transition metals such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg as a source of ammonia as the reducing agent in selective catalytic reduction (SCR) of NO x in exhaust gases from combustion processes.
[0053] In yet another aspect the invention relates to an ammonia delivery device comprising a container comprising
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg, said container being provided with one or more closable outlet opening(s) connected to a pipe and further being ing provided with means for heating the container and the ammonia absorbing salt for release of gaseous ammonia.
[0054] In the ammonia delivery device according to the invention, the closure of the closable outlet opening(s) may be in the form of one or more valve(s) known per se for use in connection with ammonia.
[0055] Heating means may be in the form of an electrical resistive heating device known per se.
[0056] The heating means may alternatively be provided as heat produced by chemical reactions.
[0057] The salt is normally heated to temperatures in the range from 10° C. to the melting point of the metal salt ammine complex, preferably to a temperature from 100 to 700° C., more preferred to a temperature from 150 to 500° C.
[0058] In a preferred embodiment of the invention the release rate of ammonia is controlled by accurate control of the heating of the container and the ammonia absorbing salt for release of gaseous ammonia. The release of ammonia is preferably further controlled by reduction valves, flow controllers or similar equipment or units. The release of ammonia from a container is preferably controlled by interaction with an electronic engine control system for delivery of an optimum amount of ammonia in a specific ratio (e.g. NH 3 :NOx=1:1) of the changing emission of NOx from the engine.
[0059] In still another aspect the invention relates to the use of an ammonia delivery device comprising a container comprising
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, wherein M is Mg, said container being provided with one or more closable outlet opening(s) connected to a pipe and further being provided with means for heating the container and the ammonia absorbing salt for release of gaseous ammonia as a source for ammonia in selective catalytic reduction of NO x in exhaust gases from combustion processes.
[0060] In yet a further aspect, the invention relates to a solid ammonia storage and delivery material comprising:
[0000] an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkali metals, alkaline earth metals, and transition metals such as Li, Na, K, Cs, Mg, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn or combinations thereof such as NaAl, KAl, K 2 Zn, CsCu, or K 2 Fe, X is one or more anions selected from fluoride, chloride, bromide, iodide, nitrate, thiocyanate, sulphate, molybdate, and phosphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, said storage and delivery material having a density of 0.9 to 1.3 g/cm 3 .
[0061] Still further, the invention relates to a method of producing a solid ammonia storage and delivery material comprising an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula:
[0000] M a (NH 3 ) n X z ,
[0000] wherein M is one or more cations selected from alkali metals, alkaline earth metals, and transition metals such as Li, Na, K, Cs, Mg, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn or combinations thereof such as NaAl, KAl, K 2 Zn, CsCu, or K 2 Fe, X is one or more anions selected from fluoride, chloride, bromide, iodide, nitrate, thiocyanate, sulphate, molybdate, and phosphate ions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and n is the coordination number of 2 to 12, said storage and delivery material having a density of 0.9 to 1.3 g/cm 3 , said method comprising the steps of
1) providing the solid salt,
2) saturating the salt with ammonia, and
3) compressing the ammonia salt complex to a density of 0.9 to 1.3 g/cm 3 .
[0062] The present invention is especially suitable for use in reduction of emission of NO x in exhaust gases from stationary and mobile combustion engines or power plants fuelled by diesel oil, petrol, natural gas or any other fossil fuels.
[0063] Thus, the present invention is also especially suitable as a source for providing ammonia in selective catalytic reduction in exhaust gasses for reduction of emission from stationary and mobile combustion engines or power plants fuelled by methanol, ethanol, hydrogen, methane, ethane or any other synthetic fuels.
[0064] Mobile combustion engines for which the invention is suitable are may e.g. be automobiles, trucks, trains, ships or any other motorised vehicle.
[0065] The invention is particularly suitable for use in connection with reduction of NO x in combustion gases from automobiles and trucks.
[0066] Stationary power plants for which the invention is suitable are preferably power plants generating electricity.
[0067] The present invention is also especially suitable for use in reduction of emission of NO x in exhaust gases from solid oxide fuel cells (SOFC). SOFC's are operated at a high temperature, where there may be a small production of NO x , which can be removed by adding ammonia using the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0068] The invention is now explained more in detail with reference to the drawings showing preferred embodiments of the invention.
Materials and Methods
[0069] MgCl 2 powder: anhydrous, >98% purity, Merck Schuchardt.
[0070] Glove-bag: Aldrich premium AtmosBag from Aldrich Chemical Company, Inc., 1001 West Saint Paul Ave., Milwaukee, Wis. 53233, USA.
[0071] Ammonia Gas: Ammonia Gas 99.9% from Hede Nielsen, Industriparken 27-31, 2750 Ballerup, Denmark.
Preparation of Ammonia Saturated MgCl 2 Powder.
[0072] The ammonia carrier, Mg(NH 3 ) 6 Cl 2 , was prepared by placing MgCl 2 powder for several days in a glove-bag containing ammonia gas at atmospheric pressure (1 bar) and at room temperature. The degree of saturation was checked by temperature programmed desorption (TPD) and verified to be near 100% of the theoretical amount. The absorption/desorption was found to be fully reversible.
[0073] The rate of absorption is dramatically increased at higher NH 3 pressures (minutes rather than days) (Touzain and Moundamga-lniamy, 1994).
[0074] An equilibrium phase-diagram of the MgCl 2 —NH 3 system is shown in FIG. 10 also showing the process of saturation when carried out at 5 bars.
[0075] Starting from point B′ (pure MgCl 2 ) the pressure was increased to 5 bars at point A corresponding to an isothermal absorption at T=298.15K and resulting in the formation of fully saturated Mg(NH 3 ) 6 Cl 2 . The rate of formation depends on the equilibrium pressure drop; however absorption is generally quite fast at ammonia pressures of more than 4 bars (Touzain and Moundamga-Iniamy, 1994). As mentioned, the desorption reaction only proceeds at elevated temperatures, which is also indicated on the path from A to B (isobaric desorption at P=5 bar).
Example 1
[0076] An ammonia delivery device was made from stainless steel in the form of a cylindrical container, having the dimensions 2R0=H=10 cm, where R0 is the inner radius and H is the height of the reactor. A photograph of the device is shown in FIG. 1 . The device was provided with five wells for insertion of thermocouples placed perpendicular to the tangent of the reactor circumference for determining the radial temperature distribution. Furthermore, a thermocouple was placed on the outer wall to measure the actual temperature of the heated steel wall. Ammonia-saturated MgCl 2 powder (258.8 grams) was then placed and compacted slightly by manual pressure to a bed density of approximately 331 kg/m 3 . A thin sheet of quartz cotton was placed on top of the salt to prevent any grains from being carried out of the reactor. As desorption of ammonia from the complex requires elevated temperature, a heating wire was wrapped around the reactor and thermal insulation (Rockwool) was placed on top of this. Using a PC with labview interface, the power to the heating tape surrounding the storage container was turned on/off when the pressure in the buffer was below/above the pressure set-point. The desorbed gaseous ammonia flowed into a small buffer container, that was placed after the desorption unit and having a volume of approximately 200 millilitres. The pressure inside the buffer was measured using a digital Kobold SEN-87 pressure meter. The position of the thermocouples (denoted T1 to T5) are shown in the below table 1 and illustrated in FIG. 2 .
[0000]
TABLE 1
Radial position of five thermocouples
Thermocouple
Radial distance from inner wall (mm)
T1
0 (inner wall)
T2
12
T3
26
T4
45
T5
50 (centre)
The total test setup is shown in FIG. 3.
[0077] A mass-flow controller (Brooks Smart Mass Flow 5850S calibrated to NH 3 ) dosed the ammonia from the buffer container into a “tailpipe” conveying a stream of carrier gas of air (1000 litres/minute) corresponding roughly to the current of exhaust gas from a small car. In addition to dosing ammonia, the same device also measured the actual flow through the valve in millilitres/minute (at T=298.15 K and P=1 bar). According to the stoichiometry of the SCR reaction, the mixture ratio between NH 3 and NOx should be approximately 1:1 (e.g. (Koebel and Kleeman, 2000; Fang and DaCosta, 2003)). The transient NOx concentration (and by that the transient NH3 concentration) in the exhaust gas from a car is very complicated to describe a continuous mathematical function and as an approximation, a sinusoidal function was used. The amplitude was set to 210 millilitres/minute and the period was set to 120 seconds. Due to limitations in the dynamics of the mass-flow controller, however, the resulting outlet flow was not completely sinusoidal. Heating of the desorption unit was controlled using the ON-OFF controller programmed along with the datacollection in Labview. The control parameter was chosen as the buffer pressure and the set-point pressure was set to 5 bars. At such high pressures it is fairly safe to assume that there is no pressure gradient across the porous bed (Lu and Spinner, 1996), and therefore the reactor pressure should be equal to the buffer pressure. It is possible to reduce the set-point pressure, which will reduce the temperature required for desorption. However, the main reason for the choice of set-point pressure was to maintain a well-defined flow through the mass-flow controller. With proper flow-mapping the flow through the valve should in principle be independent of the back-pressure.
[0078] The result of the experiment appears from FIG. 4 which shows a graphical representation of recorded temperature at positions T1 and T5 (the melting point for MgCl 2 is 714° C.) during desorption of ammonia from the ammonia-saturated MgCl 2 powder, and FIG. 5 shows the recorded pressure in the buffer container during the experiment. Phases I-IV and an intermediate phase (phase (II-III)) have been indicated in FIGS. 4 and 5 and are explained more in detail below.
[0079] During the experiment, a controller increased the temperature of the unit slowly to sustain a desired pressure of ammonia in the buffer. In the case of the experiment in FIGS. 4 and 5 , the buffer was kept at a pressure close to 5 bars. Other experiments were done at lower buffer pressures. This resulted in a lower operating temperature due to the thermodynamics of the storage material. A higher ammonia pressure gives a higher desorption temperature.
Phase (I)-Warm-up
[0080] During this phase the pressure was allowed to build up to the set-point, no ammonia was extracted during this initial warm-up phase.
Phase (II)—Desorption of First Four Moles of Ammonia
[0081] When reaching the set-point buffer pressure, heating was turned off and the mass-flow controller began to dose ammonia. This eventually caused the pressure to drop and heating was turned on again. Switching between on and off for dosing ammonia caused the pressure to oscillate around the set-point. The small oscillations in the measured out-flow (nearly sinusoidal flow) can also be seen in the large oscillations around the set-point, as it is shown in FIG. 6 .
[0082] The large (and slow) oscillations are also seen in the temperature, and due to the low effective thermal conductivity of the porous solid matrix this is most pronounced in the vicinity of the source of heat (T1). During phase II, the oscillations of the pressure and temperature continued to increase in amplitude and decrease in frequency. Combined with the large temperature gradients observed from FIG. 4 this indicates, that the reaction proceeds along an inward moving reaction front. Such a moving front will increase the way of heat-transfer, which will result in increasing amplitude and decreasing frequency of the pressure/temperature oscillations.
Phase II-III—Transition Phase
[0083] As the front moves toward the centre of the reactor, less and less ammonia is available for desorption. Eventually, a new front builds up near the heat-source, in which the fifth mole of coordinated ammonia is desorbed. This again reduces the way needed for heat-transfer and thus reduces the amplitude and increases the frequency of the oscillations. The apparently lower amplitude of the oscillations in the transition phase as compared to phase III, indicates that there still is ammonia bound as Mg(NH 3 ) 6 Cl 2 left for desorption near the centre.
Phase III—Desorption of Fifth Mole of Ammonia
[0084] The sudden increase of the amplitude marks the end of the transition phase and the beginning of the third phase, in which only the fifth mole of ammonia desorbed. The decrease of the pressure overshoot as compared to phase II is most obviously due to the fact that only one mole of ammonia was released as compared to the four moles released during phase II (cf. reactions 2 and 3), therefore reducing the overall desorption rate. However, the increased loss of heat to the surroundings due to the higher temperature level at T1 could also help moderating the temperature/pressure peaks. During this phase it is difficult to see any increase of amplitude and decrease of frequency of the pressure oscillation; however the peak temperature does increase throughout the phase.
Phase IV—Desorption of Sixth Mole of Ammonia
[0085] The amplitude of the pressure overshoot was even smaller during this phase than for phase II. One mole of ammonia was desorbed in both phase III and IV, but the increased loss of heat at T1 during phase IV helped moderating the temperature peaks and hence, also the overshoot of pressure. Since this experiment was run for several hours, including a night, a maximum allowable temperature of 500° C. was set as a safety parameter. From FIGS. 4 and 5 it can be seen, that this temperature was reached, which resulted in the loss of buffer pressure. As this occurred during the night, it was not corrected until the following morning by setting the maximum allowable temperature to 650° C. (64° C. less than the melting point temperature of MgCl 2 ). The temperature and pressure fluctuated a somewhat during this phase. This might indicate some sort of build-up of pressure and subsequent release due to mass-transfer hindrance. During phase IV, the temperature throughout the reactor became quite high. However, in an optimized system the set-point for pressure will certainly be lower than the chosen 5 bars, which will also reduce the required temperature for all three desorption reactions to occur.
[0086] Integration of the outlet flow curve in time yields the total accumulated volume of NH 3 released through the valve. This value can be converted to number of moles by means of the ideal gas law. In order for the process to be efficient, this value should be close to the theoretically predicted amount of NH 3 contained in the salt. This is easily calculated, since the ratio of MgCl 2 and NH 3 in a 100% saturated salt is 1:6. The stoichiometric calculations showed that, theoretically, 7.88 moles of ammonia should be stored within the given mass of Mg(NH 3 ) 6 Cl 2 salt (258.8 grams), while the integration of the calibrated signal from the mass flow controller revealed that 7.86 moles of ammonia was released through controller giving a very high storage efficiency of approximately 99.8%.
Example 2
Compression of Solid Ammonia Storage Medium
[0087] FIG. 7 schematically shows a device compression of the solid ammonia delivery material for the preparation of cylindrical tablets (dimensions: 13 mm in diameter; 10 mm high). In this embodiment, the solid ammonia delivery material was compressed in a chamber by applying a pressure of 2-4 tons/cm 2 using a piston compressing the powdered saturated storage material. When the piston was removed, the delivery material was in the desired shape of e.g. a tablet, a cylinder or a rod, and had a density above 80% of the theoretical crystal density.
[0088] FIG. 8 schematically shows an embodiment of an ammonia delivery device of the invention for desorption of the compressed delivery material. In this embodiment, one or more tablets of solid ammonia delivery material 1 are placed in a container 2 , which can be heated by a heating device 3 . Desorbed ammonia leaves the container through a nozzle 4 . Heat for the heating device 3 may be provided by e.g. resistive electric heating or chemical reactions. Such chemical reactions could be generated e.g. by combustion of a part of the released ammonia. If the delivery device is used in connection with SCR of NOx in exhaust gases, waste heat from the engine producing the gases can also be applied.
[0089] FIG. 9 schematically shows another preferred embodiment where only a part of the stored solid delivery material 1 is heated at a time. The solid delivery material is stored in compressed form, and introduced into a hot chamber 2 one at the time at intervals corresponding to the requirement for gaseous ammonia. The hot chamber is heated by a heating device 3 operated after the same principles as described above 2 . Gaseous ammonia leaves the hot chamber through a nozzle 4 , and when all ammonia is desorbed from a tablet 5 of solid ammonia delivery material, it is discarded into a separate container 6 .
[0090] In a similar type of embodiment, the entire storage material is separated into a number of compartments each having their own heating source so that it is possible to have complete desorption of a given fraction of the material without using any moving parts to replace saturated/unsaturated salt e.g. on-board the vehicle during use.
[0091] The bed-density of the delivery material used in Example 1 was quite low (331 kg/m 3 when compacted gently by hand) when compared to the density of MgCl 2 and Mg(NH 3 ) 6 Cl 2 (1252 kg/m 3 , cf. the below table 2).
[0000]
TABLE 2
Mass density
Molar volume
Salt
kg/m 3
cm 3 /mole
Source
MgCl 2
2325
40.86
CRC Handbook 2004
Mg(NH 3 ) 6 Cl 2
1252
157.4
Gmelins Handbook 1939
[0092] A low density means that the entire storage system would require more space. This problem was solved by compressing Mg(NH 3 ) 6 Cl 2 into solid rods having a density of 1219 kg/m 3 (97% of the solid density). TPD experiments confirmed that it was possible to desorp all ammonia from this tablet, thus increasing the potential storage capacity by a factor of 3.7 (on a molar basis) to approximately 93% of the volumetric ammonia storage capacity of liquid ammonia. A nearly quantitative desorption of ammonia from the dense material is possible because the front of desorption leaves behind a porous layer of anhydrous MgCl 2 . This automatically generates the required pore system needed for mass-transfer through the structure. This is considered an ideal combination of a) an initially very compact structure having almost no void and being easy to handle, b) a high capacity for containing and delivering ammonia, c) a low external surface area, and d) a high degree of safety.
Example 3
Comparison of the Use of Ammonia Delivery Devices of the Invention and Urea-technology
[0093] By calculating the amount of NOx (assumed to be pure NO) generated per kilometre in a model fuel (taken as pure n-octane, ρ=696.8 kg/m3), the corresponding driving distance for a given amount of ammonia or urea can be found.
[0094] Based on the EURO 3 standards (The European Parliament, 1998) as well as by the values used by some researchers (Hyundai Motor Co.: Choi et al., 2001), the assumed NOx concentrations and the fuel economies are: 150 ppm and 10 km/litre for stoichiometric combustion (typically gasoline) and 300 ppm and 15 km/litre for lean burn combustion (λ=1.5, typically diesel).
[0095] Taking 1 litre (or 696.8 g) of fuel as a basis of calculations the generated NOx per. kilometre would be 5.87·10 −2 mole/km or 0.18 g/km for stoichiometric combustion, while for lean burn combustion (λ=1.5), the NOx emission is 1.15·10 −2 mole/km or 0.34 g/km.
[0096] In the below table 3 is shown the required mass/volume of the high-density Mg(NH 3 ) 6 Cl 2 needed to drive 20,000 km (excluding the mass/volume of any equipment) compared to that of the 32.5% urea solution. The comparison is based on the combustion of pure n-octane and the above assumptions. The fuel is assumed to be pure n-octane and the exhaust is assumed to have an average molar fraction of 300 ppm NOx. The engine is assumed to run lean with a fuel economy of 15 km/litre fuel. The density of a 32.5% wt/wt urea solution is 1090 kg/m 3 and the density of the Mg(NH 3 ) 6 Cl 2 is assumed to be 1219 kg/m 3 .
[0000]
TABLE 3
Mass/20,000 km
Volume/20,000 km
Material
kg
litre
1
Urea
21.2
19.4
2
Mg(NH3) 6 Cl 2
7.5
6.2
Ratio 1:2
2.8
3.1
[0097] The results clearly show the superior ammonia storage capacity of Mg(NH 3 ) 6 Cl 2 over that of the urea solution. Combined with a high efficiency of approximately 99% this ammonia storage compound is very appropriate for the purpose. Due to the nature of the compaction of the materials, the present invention is also superior to the disclosures of WO 99/01205, where the preferred embodiment of granulated material of either Ca(NH 3 ) 8 Cl 2 or Sr(NH 3 ) 8 Cl 2 will results in a reduction in volumetric capacity of the theoretical salt densities by a factor of 1.5-2.
REFERENCES
[0000]
Fang, H. L., DaCosta, H. F., 2003. Urea thermolysis and NOx reduction with and without SCR catalysts. Applied Catalysis B: Environmental 46, 17-34.
Goetz, V., Marty, A., 1992. A model for reversible solid-gas reactions submitted to temperature and pressure constraints: Simulation of the rate of reaction in solid-gas reactor used as chemical heat pump. Chem. Eng. Sci. 47 (17-18), 4445-4454.
H. Van Vlack, L., 1989. Elements of Materials Science and Engineering, sixth Edition. Addison-Wesley Publishing Company Inc.
Hyundai Motor Co.: Choi, S.-m., Yoon, Y.-k., Kim, S.-j., Yeo, G.-k., Heesung Engelhard Corp.: Han, H.-s., 2001. Development of UREA-SCR system for light-duty diesel passenger car. SAE Technical Paper Series.
Koebel, M.; Elsener, M., Kleeman, M., 2000. Urea-scr: A promising technique to reduce NOx emissions from automotive diesel engines. Catalysis Today 59, 335-345.
Liu, Chun Yi & Aika, K.-i., 2004. Ammonia absorption on alkaline earth halides as ammonia separation and storage procedure. Bull. Chem. Soc. Jpn. 77 (1), 123-131.
Lu, Hui-Bo; Mazet, N., Spinner, B., 1996. Modelling of gas-solid reaction coupling of heat and mass transfer with chemical reaction. Chem. Eng. Sci. 51 (15), 3829-3845.
Matsumoto, S., 1997. Recent advances in automobile exhaust catalyst. Catalysis Surveys from Japan 1, 111-117.
Olovsson, I., 1965. Packing principles in the structures of metal ammine salts. Acta Cryst. 18, 889-8.93.
CRC Handbook, 2004. Handbook of chemistry and physics (web edition). Gmelins Handbuch, 1939. Magnesium teil b: Die verbindungen des magnesiums (27).
The European Parliament, 1998. Directive 98/69/ec.
The European Parliament, 1999. Directive 1999/96/ec.
The European Parliament, 2003. Directive 2003/17/ec.
Touzain, P., Moundamga-lniamy, 1994. Thermochemical heattransformation:
Study of the ammonia/magnesium chloride-GIC pair in a laboratory pilot. Mol. Crys. Liq. Cryst. 245, 243-248.
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A solid ammonia storage and delivery material A solid ammonia storage material comprising: an ammonia absorbing salt, wherein the ammonia absorbing salt is an ionic salt of the general formula: M a (NH 3 ) n X z , wherein M is one or more cations selected from alkaline earth metals, and/or one or more transition metals, such as Mn, Fe, Co, Ni, Cu, and/or Zn, X is one or more anions, a is the number of cations per salt molecule, z is the number of anions per salt molecule, and ri is the coordination number of 2 to 12, wherein M is Mg provides a safe, light-weight and cheap compact storage for ammonia to be used in the automotive industry.
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FIELD OF THE INVENTION
This invention relates to sewing machines and more particularly to method and apparatus to preload two pieces of material to be sewn into the sewing machine while sewing operation is being performed to enhance machine production and to compensate for uneven lengths of the two pieces of material.
BACKGROUND OF THE INVENTION
There are a number of commercial sewing machines on the market, one such sewing machine being described in U.S. Pat. No. 4,825,781 issued May 2, 1989. Machines of this type do a very good job of sewing together two pieces of material, such as the seam of a pants leg; however, such machines do have certain limitations.
The first such limitation is that the machine operator cannot load new material to be sewn into the machine until sewing on the prior material is completed. The loading operation is also completely manual. Thus, for one exemplary machine, while it takes approximately six seconds for the machine to sew a pants leg, it can take up to twelve additional seconds for a new piece of material to be loaded into the machine. It thus takes approximately eighteen seconds to sew a pants leg in this machine, with only approximately one third of that time being used for actual sewing. Therefore, in order to increase production from a given machine, it is desirable to be able to reduce the time required for loading the machine, and in particular to permit preloading of material into the machine so that there is some overlap between loading time and sewing time. By simplifying the load procedure permitting preload so that the loading operation may occur at the same time the sewing operation is being performed, and permitting the actual loading operation to be performed automatically, it should be possible to reduce the time required to sew for example a pants leg by as much as 50%, and even greater time savings may be possible.
The second problem is that, no matter how carefully the material is originally cut, there are frequently differences in the length of the two pieces of material being sewn. It is known that such differences in length can be compensated for by changing the feed rate at the sewing head for either one or both of the pieces of material so that on of the pieces of material has a little extra fullness in some area and/or the other piece of material is stretched slightly. For a pants leg, it is preferable that this adjustment be made over the top third of the leg (i.e. in the area above the knee). However, heretofore, the operator has been relied upon to estimate the amount of mismatch between the two pieces of material being sewn together and to manually adjust the feed rate to compensate for such mismatch. This extra labor on the part of the operator accounts in part for the time required to load ne pieces of material to be sewn into the machine. The need for the operator to estimate and make manual adjustment for mismatches also means that the operator must have a certain skill level, the need for more highly skilled operators also increasing costs. Thus, production time could be reduced, thus further reducing cost, if a mechanism were provided for automatically detecting mismatches in the pieces of material to be sewn and compensating for such mismatches.
A need therefore exists for an improved method and apparatus which increases the production obtainable from a sewing machine, and thus reduces the cost of operation thereof, by permitting preloading of material to be sewn during a prior sewing operation, and by permitting automatic detection of material mismatches and compensation for such mismatches.
SUMMARY OF THE INVENTION
In accordance with the above, this invention provides a method and apparatus for preloading two pieces of material which are to be sewn together into a sewing machine. The sewing machine has a table with the sewing head being mounted near one end thereof and an arm mounted above the table which arm is normally positioned at a distance from the sewing head. At least two grippers extend from the arm toward the table with the operator positioning the piece of material between the gripper and the table to preload the material. When the material is properly preloaded, the grippers engage the material. When the sewing head is ready to receive the material, having completed the prior sewing operation, the arm, and thus the preloaded material engaged by the grippers, is moved across the table toward the sewing head. When the material reaches the sewing head, it is disengaged from the grippers and the arm is then returned to its normal position. A separator is preferably positioned by the operator to keep the two pieces of material apart. When a separator plate at the sewing head is between the two pieces of material, the separator inserted by the operator may be kicked out or otherwise removed.
For the preferred embodiment, only a portion of the preloaded two pieces of material are on the table, with most of the material hanging down over an edge of the table. A table extension from that the edge is provided, at least in the area of the sewing head, which extension is normally down with its plane substantially at a right angle to the plane of the table. However, when the material is at the sewing head, the table extension is raised to be in substantially the same plane as the table.
A sensor is also provided for each piece of material, and a suitable means as provided for moving the sensors along the length, for example, of the hanging portion for the preferred embodiment, of the material when the material is in the preload position to detect length mismatches. The sewing means include a means responsive to a difference in length between the two pieces of material for altering the feed rate for at least one of the pieces of material for at least a portion of the sewing operation.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a top view in semiblock form of a sewing machine incorporating the teachings of this invention with the machine in the preload position.
FIG. 2 is a side view taken generally along the line 2--2 in FIG. 1.
FIG. 3 is a back view taken generally along the line 3--3 in FIG. 1 with the apparatus at a slightly later stage in its operation than as shown in FIG. 2.
FIG. 4 is a top view of the apparatus shown in FIG. 1 with the apparatus in the load position.
FIG. 5 is a partially broken side view taken generally along the line 5--5 in FIG. 4.
FIG. 6 is a partially schematic top front perspective view of an automatic feed rate control suitable for use with this invention.
FIG. 7 is a flow diagram illustrating the operation of the apparatus shown in FIGS. 1--6.
DETAILED DESCRIPTION
FIGS. 1-5 show a sewing machine of a preferred embodiment which incorporates the teachings of this invention. Referring to these figures, the sewing machine 10 has a table 12, the top surface of which is preferably of a low friction material. A sewing head 14 is mounted at one end of table 12. The sewing head may for example be of the type shown and described in conjunction with the before mentioned Pat. No. 4,825,781. However, since the exact nature of the sewing head does not form part of the present invention, the sewing head is shown only in block form and the details of this head ar not described herein. For purposes of this invention it will be assumed that material moves from right to left, as viewed in FIG. 1, through the sewing head. A suitable detector 16, such as a photo detector, is provided adjacent the left side of sewing head 14 to detect when material being sewn has exited the head. For example, assuming the top surface of table 12, at least in the area thereof under detector 16, is reflective, there would be an output from the photodetector when no material is thereunder. However, when material is between detector 16 and table 12 during a sewing operation, there would be no output from the detector.
An arm 20 is mounted above table 12, the arm being parallel to the table and spaced therefrom. The arm is normally in the preload position shown in FIGS. 1-3. Arm 20 is supported by a bracket 22 which is attached to a collar 24 which rides on a pneumatic guide rail 26. Pneumatic pressure to drive collar 24 along rail 26 toward sewing head 14 is provided from a pneumatic line 30 through chamber 28. Similarly, pneumatic pressure to drive collar 24 away from sewing head 14 is provided from a pneumatic line 32 through pneumatic chamber 34.
A pair of guide fingers 38A and 38B rest on the top of table 12 at their lower ends. At their other ends, the fingers are attached by brackets 40 to arm 20. A pressure plate assembly 42 is also mounted to arm 20. Assembly 42 consist of a pressure plate 44 having a pair of guide rods 46A and 46B extending therefrom. Each guide rod 46 passes through a corresponding guide hole 48A and 48B formed in a corresponding bracket 50A, 50B, which brackets are mounted by screws, rivets or other suitable means not shown to arm 20. The pressure plate assembly is completed by a pneumatic cylinder 52 which is mounted to arm 20 by a bracket 54. Pneumatic cylinder 52 has a piston 56 which is attached to the center of pressure plate 44 and in conjunction with the pneumatic cylinder controls the raising and lowering of the pressure plate assembly. Pneumatic pressure is applied to piston 52 from a suitable source through pneumatic line 58.
The final element attached to arm 20 is a separator finger 60 which is hingedly connected to a bracket 62. Bracket 62 is attached to arm 20. Finger 60 has a projection 64 at its upper end which is adapted to co act with bar or arm 66 mounted at the sewing head end of table 12 to kick separator 60 in a manner to be described later out from between two plies of material which are to be sewn. Arm 66 is supported by a bracket 68 which is attached to table 12. A separator plate 70 is also provided in the area of arm 66 which is adapted to fit between two pieces of material which are being sewn.
A table extension 72 is mounted to the right edge of table 12 by a pair of hinges 74. Table extension 72 is raised to the position shown in FIG. 4, where it is in the plane of table 12 by a pneumatic cylinder 74. Cylinder 74 is attached at one end by a shaft 76 to the housing 77 supporting table 12 and has a pneumatic piston 78 extending from its other end which piston is attached by a bracket 80 to the underside of table extension 72. Pneumatic pressure is applied to piston 74 through a pneumatic line 82. A detector 84, for example an optical detector which is mounted to table 12 by a bracket 86, is provided to indicate when material is no longer on table extension 72, at which time piston 74 may lower table 72 to the position shown in FIGS. 1 and 2 in preparation for the next material loading operation.
A separator plate 90 is mounted to hang down from the right side of table 12 adjacent arm 20 when arm 20 is in its preload position shown in FIGS. 1 and 2. Plate 90 is supported by a bracket 92 attached by suitable means to table 12. Separator plate 90 has an open channel 94 formed therein. A pair of light sources 95A and 95B (FIG. 3) and corresponding photodetectors 96A and 96B are provided which are mounted to a detector assembly 97 attached by a bracket 98 to a collar 100 on pneumatic column 102. Pneumatic pressure to drive collar 100, and the detector assembly 97 attached thereto, downward is applied through pneumatic line 104 and pneumatic pressure to drive the collar and detectors in the upward direction to return them to the position shown in FIG. 2 is applied through pneumatic line 106. The function of the assembly consisting of elements 90-106 will be described shortly.
Table 12 also has a "ready" button 110 mounted thereon which the operator may hit when the preload operation has been completed. There are also a plurality of air holes 112 in the top surface of table 12 through which air under low pressure may be applied from a suitable source. Air may either be continuously applied through holes 112 or may only be applied when material is being moved from the preload to the sewing position. The function of air holes 112 and the air flowing therethrough is to provide air flotation for the material as it moves over table 12, thus further reducing friction between the material and the table.
A processor and control unit 114 is also provided which is operative to control the operation of the apparatus 10. In particular, control 114 controls appropriate valves (not shown) o other suitable pneumatic controls to apply pneumatic pressure to the various pneumatic lines at the appropriate points in the operation of the apparatus. While the sequence in which the valves are controlled to perform the various functions is important, and this sequence is illustrated in FIG. 7, the exact manner in which the various valves are controlled and in which the other controls are performed is not critical to the invention and these functions may be performed in any standard manner known in the art.
Finally, referring to FIG. 6, the system has a pair of servomotors 115A and 115B which are controlled by suitable electrical lines, 116A and 116B respectively, from processor and control device 114 in response to a detection of a difference in length between two pieces of material to be sew or in response to a manually applied input. Each servomotor 115 has an output shaft 117A, 117B which is connected through a suitable gearing and linkage mechanism 118A, 118B to a shaft 119A, 119B having a pinion 121A, 121B at the end thereof. Each gear and linkage mechanism 118 converts a rotation of the corresponding shaft 117 into a suitable corresponding linear movement of pinion gears 121. Pinion gears 121 mesh with corresponding racks 123A and 123B extending from sewing head 14. Rack 123A is connected to an existing mechanism within the sewing head 14 which controls the feed rate for the upper ply of material being fed through the sewing head 14, while rack 123B connects to an existing mechanism in the sewing head which controls the rate at which the lower ply of material is fed through the sewing head. Thus, processor 114 may, by applying suitable inputs to servomotors 115A and 115B, independently control the feed rate of each ply of material. The manner in which the feed rate control mechanism shown in FIG. 6 is utilized will be described later.
FIG. 7 illustrates the operation of the system shown in FIGS. 1-5. Assume initially that two pieces of material which are in sewing head 14 are being sewn, that table extension 72 is in the raised position shown in FIG. 4, that arm 20 and the elements connected thereto are in the preload position shown in FIG. 1, that pressure plate assembly 42 is in the raised position shown in FIG. 2 and that the detector assembly 97 mounted to sleeve 100 is in the up position also shown in FIG. 2. At this time the operator positions two pieces of material which are to be sewn together in the apparatus by passing the two pieces of material under pressure plate 44 and under the fingers 38 until the leading edge of both pieces of material are aligned with the forward edge of fingers 38 and the left edge of the material is just to the left of the left edge of finger 38A. Fingers 38 thus serve as a guide for preloading the material. This is operation 120 shown in FIG. 7. The material 125 as preloaded is shown in phantom lines in FIGS. 1 and 2. From these figures, it is seen that only a small portion of the material is actually on table 12 at this time, with most of the material hanging over the right edge of the table. The operator adjusts the material hanging over the right edge so that one piece of material is on each side of separator plate 90. The operator also places separator finger 60 between the pieces or plies of material as shown in FIG. 2. When these operations are completed the operator is finished preloading the piece of material and indicates this by hitting ready button 110 (step 122).
Once ready button 110 has been pressed by the operator, the operation proceeds to steps 124 and 126 to perform two separate operations more or less simultaneously. During step 124, pneumatic pressure is applied through line 58 to pneumatic cylinder 52 to force piston 56 downward causing pressure plate 44 to press material 125 against the top of table 12.
During step 126, pressure is applied through line 104 to column 102 to drive collar 100 downward. This causes detector assembly 97 to move down along the pieces of material 125 hanging down on either side of separator plate 90. During this operation, piece of material 125B is between light source 95B and photodetector 96B, while piece of material 125A is between light source 95A and photodetector 96A. When each photodetector reaches the end of its respective piece of material, it generates an output to processor 114. Processor 114, during step 128, determines the difference in the time at which it receives the outputs from detectors 96A and 96B and utilizes this, during step 128, to determine from the known speed at which collar 100 is being driven, the difference in length between the two pieces of material 121A and 121B. Once the difference determination operation has been completed, pneumatic pressure is applied to line 106 to return collar 100 and the detector assembly 97 attached thereto to the position shown in FIG. 2.
From step 128, the operation proceeds to step 130 during which an adjustment is provided by processor and control 114 to sewing head 14 to control the rate at which either one or both of the pieces of material will be fed through the sewing head for at least a portion of the sewing operation. As indicated previously, assuming it is pants legs which are being sewn, it is desirable that the adjustments, which may be either adding fullness to the longer piece of material, stretching the shorter piece of material or both, is performed over the first third of the pants leg in the area above the knee. The adjustment which is determined to be required in order to correct for the length difference, which adjustment may for example be stored in a read only memory which is addressed by length differences, is preferably retained in processor 114 and applied to sewing head 14 when the now preloaded pieces of material 121 are loaded into the sewing head (see step 147).
Once the operations described above have been completed, nothing further happens until the material being sewn is no longer over photo detector 84. Thus, as illustrated by step 132, when material is no longer over detector 84, the operation proceeds to step 134 to either apply pneumatic pressure to pneumatic line 82 in a direction to cause table 72 to be lowered, or to merely remove pneumatic pressure from line 82, permitting table extension 72 to return to its lowered position shown in FIGS. 1 and 2 either by gravity or under the action of a spring or other suitable biasing means.
When the steps described above have been completed, the system, as illustrated by step 136, monitors to determine if material is still under detector 16. If material is still under detector 16, the sewing head is still sewing the loaded piece of material and is not ready to receive a new piece of material. When the piece of material being sewn is completed, an output is obtained from detector 16 which is applied to processor 114, indicating a "yes" output from step 136.
When this happens, material 125 may be loaded into the sewing head. This is accomplished during step 138 by applying pneumatic pressure to line 30 to drive collar 24 along rail 26 toward sewing head 14. This causes arm 20 and the various elements attached thereto to also move toward sewing head 14. In particular, since pressure plate 44 is bearing against material 125, it causes material 125 to be moved across the low friction top of table 12 toward the sewing head. Fingers 38 hold the leading edge of the material against the table. Since most of the material is hanging over the edge of table 20, such friction as there is on the material does not tend to skew the material, resulting in the alignment of the material being generally maintained.
During step 140, a determination is made as to whether the material has reached the sewing head, with pneumatic pressure continuing to be applied through line 30 until this occurs When it is detected that the material is at the sewing head 14 by, for example, collar 24 reaching a predetermined point on rail 26, two operations occur. The first operation is a mechanical operation which does not depend on a detection of the material reaching the sewing head, and actually occurs slightly before the material reaches this point. As illustrated by step 142, when the material approaches sewing head 14, ar 66 contacts extension 64 on separator finger 60 kicking the separator finger 60 up and out from between pieces of material 125A and 125B. Because of the relative position of arm 66 and separator plate 70, separator 70 is between the two pieces of material when this occurs. The mechanics of this operation are best seen in FIG. 5.
The detection of the material reaching the sewing head causes a signal to be applied to control 114. In response, during step 144, control 114 either causes pneumatic pressure to be applied to cylinder 52 in a direction to raise piston 56, and thus to raise pressure plate 44, or merely removes pneumatic pressure from line 58, permitting piston 56 to be raised by a spring or other suitable biasing means. At the same time, pneumatic pressure is applied through line 82 to pneumatic cylinder 74, extending piston 78 to raise table extension 72 to the position shown in FIG. 4 with the plane of the extension being generally in the same plane as that of the table 12. This is illustrated by step 146.
Finally, at this time, the adjusted for difference in length between the two pieces of material, which was determined during step 130 and stored, is retrieved by processor 114 and is utilized to generate an appropriate signal or signals over line 116A and/or line 116B to the appropriate one or more of the servomotors 115. This results in a movement of the appropriate one or more of the shafts 117 which causes a corresponding movement of the appropriate arm or arms 119. This results in the appropriate one or more of the racks 123 being moved in an appropriate direction to adjust the feed rate of the upper piece of material 125A and/or lower piece of material 125B so as to compensate for the difference of length in the two pieces of material.
When the operations indicated above have been completed, the apparatus is ready to sew the two pieces of material 125A and 125B and control 114 causes the sewing operation to begin (step 148). At the same time, control 114 applies pneumatic pressure to line 32 to drive collar 24 and the arm 20 attached thereto back to the preload position shown in FIGS. 1 and 2. This is illustrated by step 150. When arm 20 is in its original position, a cycle of operation has been completed and the apparatus is ready for the operator to preload the next two pieces of material to be sewn. The operation this returns to step 120.
A method in apparatus is thus provided which permits material to be preloaded while a sewing operation is being performed and substantially reduces the period of time required to load a piece of material by eliminating the need for the operator to determine length differences between the two pieces of material being loaded and to make feed rate adjustments in the machine for such differences. The time required to complete a single sewing operation may thus be reduced by 50% or more resulting in substantially enhanced production from a single sewing machine.
While for the preferred embodiment, the various drives have been illustrated as being performed pneumatically, it is apparent that such operations could also be performed hydraulically or that suitable drive motors could be utilized for performing each of these operations. Further, while the material 125 has been illustrated as being engaged by having a pressure plate 44 press it against table 12, it is apparent that the material could be engaged in other ways. For example, vacuum could be applied to the lower surfaces of plate 44, fingers 38 or both in order to engage the material so that it may be moved from the preload to load position. Further, while photo detectors have been illustrated for performing the various detection operations, other types of detectors could also be utilized. Similar variations might also be made in the various other components of the system.
In addition, while for the preferred embodiment of the invention material 125 has been shown as hanging over the edge of table 12 during the length detection operation, and for various reasons indicated, this mode of operation is preferred, it is within the contemplation of the invention that the length difference detection operation could be performed with the material on the table 12 rather than hanging over the edge thereof. Similarly, while it is preferred that the length difference determination be fully automatic so that the operator need not become involved in this operation at all, it is also within the contemplation of the invention that this operation could be semi automatic. For this mode of operation, the operator would visually determine the difference in length between the two pieces of material, but rather than the operator having to manually enter an adjustment based on this difference determination, the operator would merely have to enter the estimated length difference into the processor 14 by suitable means. For example, assuming that, for a given operation, the difference in lengths would not exceed one inch, eight buttons could be provided, either on processor and control 114 or at another suitable location, with four of the buttons for the upper ply being longer in increments of one quarter inch and the other four buttons for the lower ply being longer in increments of one quarter inch. The operator would merely operate the appropriate button before hitting button 110, and processor 114 would automatically determine the appropriate adjustments in feed rate.
Thus, while the invention has been particularly shown and described with reference to a preferred embodiment, the foregoing and other changes of form and detail made therein by one skilled in the art without departing from the spirit and scope of the invention.
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An improved method and apparatus is provided for use in a sewing machine. The improvements include preloading two pieces of material which are to be sewn together. The preloading is accomplished by positioning pieces of material to be sewn under a gripper spaced from the sewing head on a table while prior pieces of material are being sewn. The gripper engages the material and, when the prior sewing operation is completed, the gripper is moved across the table toward the sewing head to load the preloaded pieces of material. When the two pieces of material are preloaded, most of the material hangs over an edge of the table and the lengths of the pieces of material are determined by movable detectors.
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PRIORITY CLAIM
[0001] The present application is a Continuation of U.S. patent application Ser. No. 10/665,332 filed on Sep. 17, 2003; which is a Continuation of U.S. patent application Ser. No. 10/004,939 filed on Dec. 3, 2001; which is a Divisional of U.S. application Ser. No. 09/456,835 filed on Dec. 7, 1999, the entire disclosure of these patents/applications are expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to a vacuum grabbing device used to grip and maneuver a suspect area within a body cavity. More specifically, the invention is directed to a vacuum device for gripping a suspect lesion found in a body cavity and positioning it so that it can be excised and withdrawn from the body cavity.
DESCRIPTION OF RELATED ART
[0003] Endoluminal procedures have become very common, and millions of these procedures are performed each year in hospitals around the world. An endoluminal procedure is a medical procedure that takes place within one of the many tube-like cavities, also called lumens, that are present within the human body. Endoluminal procedures may take place in vascular, gastrointestinal, or air exchange lumens, and may involve disease diagnosis as well as treatment of certain diseases.
[0004] Endoluminal procedures are often performed by using a device known as the endoscope. An endoscope is a tube, either rigid or flexible, which is introduced through an opening into a lumen in the human body. In the case of the gastrointestinal passage, the endoscope can be inserted either through the mouth or through the rectum. The endoscope may be used simply to hold the lumen open for examination, but often also carries light and vision systems, so that the operator can see within the lumen. The endoscope also often includes a working channel, usually formed within the body of the endoscope, so that the surgeon can insert and withdraw other instruments and diagnostic or treatment devices through the endoscope, to easily reach the position within the lumen being observed by the endoscope.
[0005] One important use of the endoscope is to allow the surgeon to view the patient internally, even when the portion of the patient's body cavity to be viewed is not in a direct line of sight from outside of the body. For this purpose, endoscopes typically contain a lens coupled to a visual display device by fiber optic cables, so that the body cavity in front of the endoscope can be remotely viewed on a TV screen. This common procedure is known as laparoscopy, and involves inserting the endoscope into the patient through a small incision made by the doctor, or alternatively through natural body openings like the colon or the esophagus.
[0006] Another common application of endoluminal procedures is the removal of tumors or of suspected tumor lesions inside the body cavity. In a conventional retrieval operation, an endoscope is inserted into an internal cavity of the patient, such as the colon. The endoscope is used to identify and locate the suspect region within the internal cavity, so that the suspect area can be removed. Conventionally, graspers have been used to grip tissue and draw it into a device for excision. Staples are then used to close the opening so that it may heal more effectively. The graspers are manipulated from outside the body and the cutting and stapling operations also are controlled and manipulated from outside the patient's body. Tiny grippers are generally used to grasp the lesion, but their positioning and the amount of tissue they grip is inaccurate, and often too much or too little tissue is removed.
[0007] The use of endoscopes typically reduces the size of the incision needed to perform a surgical procedure, thus allowing the patient to recover faster. In some cases no incision is necessary, since the endoscope is introduced through an existing body opening. Various types of tools such as cutters, vacuum suction devices, and other tools can be inserted through a working channel of an endoscope, and can be operated by the surgeon as they are guided to the appropriate section of the body cavity through the working channel of the endoscope. The tools are manually steered by the surgeon from the proximal end of the endoscope, i.e., the end remaining outside of the body. Other devices such as fiber optic cables used to carry illumination and images are generally part of the endoscope itself, and do not intrude in the working channel of the endoscope.
[0008] One specific tool that can be used in conjunction with the endoscope is the full thickness resectioning device, or FTRD. The FTRD is inserted in the body cavity, and has a working channel through which an endoscope and other tools can be inserted. The endoscope is advanced under visual observation until a desired location is visible. The FTRD is then pushed along the endoscope to the proper location within the body cavity, at which point other devices may be inserted through the working channel of the FTRD to the endoscope's location. The tissue to be removed is drawn into a chamber of the FTRD and then cut away from the surrounding healthy tissue while ensuring that no part of the tissue to be removed remains within the body cavity. The FTRD simultaneously staples together the severed sides of the healthy tissue to close up the wound and promote healing. Alternatively, the tissue may be stapled around the tissue to be removed before cutting. This procedure may eliminate the need for surgery and expedites recovery. However, one difficulty of using the FTRD to remove a tumor is that it may be difficult to bring the entire tumor into the chamber, and to ensure that no part of the tumor has been left in the body cavity.
[0009] When a biopsy or a resectioning is performed either using an FTRD or another biopsy device, the device is required to grip the suspect tissue before it is cut away. When the FTRD is used, the wound left by the removal of a large suspect section of tissue is closed by stapling together the surrounding healthy tissue so it may heal more easily. However, when a biopsy is conducted, the sample taken is generally much smaller, and therefore it is not necessary to use staples to close the wound. In both cases, it is important to grip the proper amount of tissue, so that the suspect portion of body cavity tissue is accurately pulled away from the wall of the body cavity lumen.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a vacuum grabber device that substantially obviates one or more of the problems due to the limitations and disadvantages of the related art, and can be used to more easily and accurately remove suspect areas in body cavities. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. Other advantages of the invention will be realized and obtained by the apparatus and method particularly pointed out in the written description and claims hereof, as well as the appended drawings.
[0011] To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, the invention is a vacuum grabber device adapted for use with an insertion device inserted in the body cavity, comprising a vacuum line slidable within a working channel of the insertion device and having a distal end insertable in the insertion device, a substantially transparent flexible cup attached to the distal end of the vacuum line foldable to fit within the working channel and deployable to a configuration substantially funnel shaped, means for applying a vacuum to the flexible cup, and means for positioning the deployed flexible cup within the body cavity such that the flexible cup can hold a selected inner portion of the body cavity by vacuum, and can be at least partially withdrawn into the insertion device while holding the selected inner portion. A vision device is used to view the selected inner portion of the body cavity through the flexible cup.
[0012] In another embodiment, the invention is a method for removing a selected portion of tissue from a surface of a body cavity, having the steps of inserting into the body cavity an insertion device, advancing through the insertion device a substantially transparent flexible cup in a folded configuration within the insertion device, deploying from the insertion device the flexible cup in a substantially funnel shaped configuration, and visually positioning the deployed flexible cup adjacent to the selected portion of tissue by observing the selected portion of tissue through the flexible cup. The steps of the method also include applying a vacuum pressure through the flexible cup to draw the selected portion of tissue into the flexible cup, and at least partially withdrawing the flexible cup proximally into the insertion device to draw the selected portion of tissue into a desired position relative to the insertion device.
[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in an constituent part of this specification, illustrate several embodiments of the invention and together with a description serve to explain the present invention. In the drawings:
[0015] FIG. 1 is a diagram showing a cut-away view of the vacuum grabber device according to one embodiment of the invention, deployed from an insertion device located within a body cavity;
[0016] FIG. 2 is a diagram showing a cut-away view of the vacuum grabber device according to an embodiment of the present invention, in a folded configuration within the insertion device; and
[0017] FIG. 3 is a diagram showing the flexible cup of the vacuum grabber device shown in FIG. 2 , in a deployed configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention provides a device and method to ensure that a selected inner portion of a body cavity is gripped, so that a suspect area possibly containing a tumor as well as a small surrounding area of healthy tissue may be removed. The additional amount of healthy tissue being removed is necessary to provide a safety margin portion of tissue, to ensure that all of the suspect area has been cut away from the body cavity. The invention also ensures that the entire tissue sample that has been cut is actually removed from the body cavity before the endoscope and associated tools are removed. The invention prevents the cut tissue from falling out of the device and being left within the body cavity, so that further study of the removed tissue to perform a diagnosis is possible. The invention protects the cut tissue from the surrounding area while withdrawing it from the body cavity, so that the sample is not contaminated by extraneous materials on the way out of the body cavity. In addition, the invention limits the amount of healthy tissue surrounding the suspect area that is damaged when the suspect area is removed from the body cavity.
[0019] FIG. 1 shows a diagram of an embodiment according to the invention, used in conjunction with a FTRD to remove a suspect area from a body cavity. FTRD 10 is inserted within a body cavity 20 either through an incision made by the surgeon or through a natural opening of the cavity. Body cavity 20 is roughly tubular in shape, and has an inner surface 22 that includes a suspect area 24 . The suspect area 24 may be either a lesion that has to be removed and analyzed to determine if it is cancerous, or a growth such as a polyp that has to be removed, or from which a biopsy must be taken. The vacuum grabber device 30 is inserted inside a working channel 36 formed in the center of the FTRD 10 , and includes a vacuum line 32 and a flexible cup 34 attached to the vacuum line 32 .
[0020] The vacuum grabber device 30 is adapted to be inserted in the FTRD 10 , so that both components can be introduced within the patient's body cavity 20 . The distal end of FTRD 10 is placed in position near the suspected lesion 24 located on inner wall 22 of the body cavity 20 , and the vacuum grabber device 30 can thus also reach the suspected lesion 24 . When vacuum grabber device 30 is inserted in the working channel of FTRD 10 , the flexible cup portion 34 is in the folded configuration, so that it can more easily travel through working channel 36 . FIG. 2 shows this configuration. Once FTRD 10 is positioned within the body cavity 20 near the suspect region 24 , head assembly 38 of the FTRD 10 is opened, for example by pushing on control wire 40 which connects the head assembly 38 to an area outside of the patient's body. Once head assembly 38 is opened, vacuum grabber device 30 is pushed outside of FTRD 10 through an opening between the main body of FTRD 10 and the head assembly 38 .
[0021] Although the present embodiment of the invention is described in conjunction with a FTRD, other insertion devices capable of excising a portion of tissue within a body cavity can also be used. The present invention is thus generally usable to capture a suspect portion of the inner surface of a body cavity so that treatment, observations or removal to the suspect portion of tissue may be performed.
[0022] In another embodiment according to the invention, vacuum grabber device 30 could be inserted into the patient's body cavity 20 by means of an insertion device other than an FTRD that can shield the vacuum line 32 and the flexible cup 34 . Once the insertion device reaches the suspect area of interest, an opening could be made in the insertion device to eject the vacuum grabber device 30 . For example, the insertion device could be similar to the FTRD, but without the ability to cut and staple the tissue of the body cavity 20 . As described above, the cutting and stapling functions could be performed by additional tools inside or adjacent to the insertion device.
[0023] As shown in FIGS. 1 and 3 , vacuum grabber device 30 is pushed outside of the opening made between head assembly 38 and the main body of FTRD 10 , at which point the folded flexible cup 34 automatically deploys into a substantially funnel shaped configuration.
[0024] In a preferred embodiment according to the invention shown in FIG. 3 , the flexible cup in the deployed configuration has a substantially funnel shape, with a small opening 31 connected to the vacuum line 32 , and a larger opening 46 adapted to be placed over the suspect region 24 that requires treatment. The flexible cup can have openings that are not round, as long as it can be connected to the source of vacuum, and the large opening can cover the desired portion of tissue.
[0025] After exiting the working channel 36 of FTRD 10 , the flexible cup 34 opens to its deployed configuration automatically, due to the force exerted by resilient elements that make up the structure of flexible cup 34 . For example, a resilient ring-like structure 42 can be disposed near the large opening 46 , so that once it is no longer constrained, flexible cup 34 will open to its funnel configuration. In addition, or instead of resilient ring 42 , several resilient ribs 44 can be located on the sides of flexible cup 34 to force it in the deployed configuration once its no longer constrained within working channel 36 . The resilient elements can be embedded in a transparent membrane 40 forming the flexible cup, or can be placed inside or outside of membrane 40 . Other configurations of resilient elements 42 and 44 could be used, such as spiral configurations, multiple rings, or any other known configurations that will open flexible cup 34 to its proper shape.
[0026] The vacuum grabber device 30 can be moved axially along the inside of body cavity 20 by simply pushing or pulling on the vacuum line 32 . In addition, in one embodiment according to the invention, flexible cup 34 is placed at an angle from the center line of vacuum line 32 , so that rotating vacuum line 32 will cause large opening 46 of flexible cup 34 to sweep in a generally circumferential direction along the inner surface 22 of body cavity 20 . This configuration allows large opening 46 to be placed over a selected portion of the body cavity.
[0027] In one preferred embodiment according to the invention, the flexible cup 34 is made of a flexible polymer that is clear, for example, a plasticized silicon material. Other materials could be used that are transparent and substantially air tight, so that a vacuum can be applied and held by the flexible cup. The materials preferably can insulate the suspect lesion or other tissue that was removed from the surrounding body cavity, so that it will not be contaminated by extraneous materials when it is withdrawn from the body. The flexible cup must be sufficiently transparent so that the tissue in question can be seen through the flexible cup. For example, an endoscope could be used to look at the tissue through membrane 40 .
[0028] In yet another embodiment according to the invention, a mesh 50 or other type of screen can be located in the vacuum line 32 , or near the small opening of flexible cup 34 . This screen is designed to prevent portions of the tissue that was removed from traveling down the vacuum line, and can also be used to form a holding area for the tissue, so that it will be protected from contamination by vacuum line 32 and by the membrane 40 of flexible cup 34 .
[0029] The operation of vacuum grabber device 30 will now be explained with reference to FIGS. 1 through 3 . FTRD 10 or another type of insertion device is inserted in body cavity 20 and is navigated by the surgeon to a location near suspect lesion 24 , located on inner surface 22 of the body cavity 20 . At this point, vacuum grabber device 30 is inside working channel 36 of FTRD 10 , and flexible cup 34 is in the folded configuration shown in FIG. 2 . When FTRD 10 is in place, head assembly 38 is opened, and flexible cup portion 34 is ejected outside of FTRD 10 .
[0030] As explained above, flexible cup 34 opens in its funnel configuration once no longer constrained in working channel 36 . The surgeon can look for suspect lesion 24 through the endoscope 11 which is also inserted through the working channel of FTRD 10 , and can position flexible cup 34 over the suspect lesion by rotating, pulling and pushing vacuum line 32 . By looking with endoscope 11 through transparent membrane 40 of flexible cup 34 , the surgeon can position the funnel-like flexible cup over the suspect lesion 24 , and can start applying a vacuum by operating vacuum means, such as vacuum pump 60 , which can provide both an adjustable vacuum and positive pressure in vacuum line 32 .
[0031] While looking through transparent membrane 40 of flexible cup 34 , the surgeon can vary the amount of vacuum and positive pressure applied to the flexible cup 34 , so that the selected inner portion of the body cavity containing the suspect lesion 24 as well as a safety margin portion 26 of healthy tissue surrounding the suspect lesion 24 is gripped and contained within flexible cup 34 . In a preferred embodiment, the safety margin portion 26 can extend beyond lesion 24 by about 3 mm to 6 mm.
[0032] By looking with endoscope 11 through transparent membrane 40 of flexible cup 34 , the surgeon can position the funnel-like flexible cup over the suspect lesion 24 , and can start applying a vacuum by operating vacuum means, such as vacuum pump 60 , which can provide both an adjustable vacuum and positive pressure in vacuum line 32 .
[0033] The surgeon at that point can operate cutting device 56 that is part of the FTRD 10 , to separate the selected inner portion of the body cavity from the rest of inner surface 22 . For example, cutting device 56 can be an extendable and movable blade. A stapling portion 58 of FTRD 10 can be used at that point to close the wound left by the removed portion of the body cavity, so that healing will be promoted. The specific configuration of cutting device 56 and stapling portion 58 can vary, as long as a portion of the body cavity drawn inside FTRD 10 is cut and the severed sides of the remaining healthy tissue are stapled together.
[0034] The selected inner portion of body cavity containing suspect lesion 24 as well as a margin of safety portion 26 of healthy tissue is thus held by vacuum within flexible cup 34 , and after cutting is withdrawn from the body of the patient while being protected from contamination by membrane 40 of flexible cup 34 . A pathology study of suspect lesion 24 can then be carried out without the concern that the results may be affected by possible contamination of the sample.
[0035] According to one embodiment of the invention, the selected inner portion of body cavity that was removed can be held near the flexible cup 34 by a screen 50 acting as a sample catcher. Alternatively, the selected inner portion can be drawn by vacuum all the way down vacuum line 32 , and can be collected outside of the body at the proximal opening of vacuum line 32 .
[0036] In one embodiment, FTRD 10 can be inserted into the patient and can carry an endoscope in a working channel of the FTRD. Alternatively, the FTRD could be inserted separately from the endoscope, in the same cavity. The important consideration in positioning the endoscope is that the surgeon must be able to see the flexible cup 34 and the suspect lesion area 24 , so that the transparent flexible cup 34 can be correctly placed over the lesion area 24 , and the selected inner portion of the body cavity can be drawn within flexible cup 34 .
[0037] In yet another embodiment according to the invention, flexible cup 34 can be provided in various sizes, so that the appropriate cup can be applied to different size lesions to ensure that the entire lesion plus a safety margin of healthy tissue can be drawn inside the flexible cup 34 . In addition, for cases where the lesion 24 has a very irregular shape, specially designed flexible cups could be used, either having very high flexibility or having specific shapes of the large opening 46 to accommodate the irregularly shaped lesion. In the latter case, flexible cup 34 should have dimensions commensurate with the largest dimension of the lesion, such as the lesion length or diameter. An increased vacuum may also be necessary to firmly hold a lesion having an irregular shape within flexible cup 34 .
[0038] It will be apparent to those skilled in the art that various modifications and variations can be made in the structure and methodology of the present invention, without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A grabbing device includes a transparent flexible cup that can be placed adjacent to a selected region of an inner surface of a body cavity. The flexible cup is visually put in place by the surgeon, and a vacuum is applied to draw a selected amount of tissue into the flexible cup, so that it may, e.g., be excised. The device may also retrieve the tissue excised from the body cavity.
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This application is a continuation-in-part of Ser. No. 138,704, filed Apr. 9, 1980, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates broadly to the field of printing apparatus and more specifically to the field of non-impact offset printing apparatus wherein cut sheet paper is fed to a rotatable drum type printing apparatus for accurate registration of the margins of the printed matter on each sheet.
2. Description of the Prior Art
In a non-impact printer of the offset type, it is necessary to accurately and repeatably match up the paper to its intended image so that when the image is affixed to the page the proper margins are achieved. A mechanism for providing this makes for repeatable registration of printed matter in the direction of paper travel assuming proper registration transverse to the paper's motion is achieved by some other means as for example, edge guides or guide walls, etc.
In a compact non-impact printer it is possible for the image to be placed on the offset medium (drum or belt) before a sheet of paper is ever fed. Therefore, it is possible for feed and transport error to affect registration. The motion of the paper must be "recalibrated" so that the page will meet up with its intended image. To provide this recalibration, registration fingers or an interposer become a necessary adjunct to the printing apparatus.
There are several requirements that such a mechanism should fulfill. The mechanism should not take an inordinate amount of space. Its location should be as close as possible to the transfer location. It should be relatively inexpensive and reliable to maintain and operate. It should be mechanically linked (i.e. through timing belts) to the offset medium for highest accuracy. Its motion should provide the proper transition from paper path speed to transfer speed. It should be a cyclic device with a frequency of one actuation per registered sheet of paper. A number of registration methods are possible that attempt to solve this task. However, they all fall short in one or more of the above requirements.
For example, rotating fingers are simple, but they take up too much space and they do not provide the ideal transition motion that is required for smooth operation of the device. A belt with fingers attached would work, but belts are relatively expensive.
SUMMARY OF THE INVENTION
The mechanism of the present invention, however, fulfills all of the necessary requirements. The path of a finger appropriately placed on the coupler of a four-bar mechanism can be made to coincide with the ideal path for registration fingers. Also, through more detailed synthesis, the speed of the finger can be tailored to provide the ideal transition between higher speed relating course paper path motion and the lower, more finely controlled speed of the transfer area. The present mechanism is compact, can be placed close to the transfer point and one revolution of the input link of the device provides for the registration of exactly one sheet of paper with all of its margins accurately maintained. Since the present four-bar interposer apparatus dwells below the paper path, the gap between sheets is decreased to a minimum at the transfer point which is a factor in increasing the throughput of a cut sheet printer. The four-bar interposer mechanism therefore represents a novel improvement over the existing methods earlier referred to.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, slightly enlarged, of the multiple paths available to the present four-bar interposer mechanism apparatus;
FIG. 2 is a view of a portion of the device of FIG. 1 showing the interposer mechanism in its active position to engage a sheet of paper on its inward path toward the receptor drum; and
FIG. 3 is a schematic diagram of the acceptable maximum mechanism envelope or path of an interposer device for use with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In a non-impact printer of the offset type, it is necessary to accurately and repeatably match up paper to its intended image so that when the image is impressed on the page the proper margin is achieved. In a compact non-impact printer, it is possible for the image to be placed in the offset device (drum or belt), before a sheet of paper is fed. Therefore, it is possible for feed and transport error to affect registration. The novel mechanism described herein is a means for providing repeatable top-to-bottom registration of printed matter transferred to cut sheet paper fed in the so-called "portrait" direction which in the case of an 81/2"×11" sheet of paper is the 11" direction or dimension.
In the case of general printer development, the following features are desirable in an interposer;
1. It must operate at one cycle per sheet for machine timing advantage.
2. It must operate in an area very close to the offset device for keeping transport error from creeping back in after registration is accomplished.
3. It must be compact in size.
4. It must be inexpensive to manufacture.
5. It must be reliable.
6. It must be mechanically connected to the transfer movement mechanism and/or the offset media for accurate link-up with paper sheets.
7. The speed match-up for proper registration action must be accurate.
The apparatus embodying the present invention, as seen in FIG. 1, is a novel means for providing repeatable top-to-bottom registration of untreated, readily available, cut sheet paper (e.g. 81/2"×11") prior to the information data transfer process. Blank sheets of paper from an input hopper (not shown) are advanced to a process station which may, for example, be a rotating photo-receptor drum. In order for the data to be intelligible, the blank paper must be registered (or synchronized) with the image that has previously been placed upon the receptor drum. This means that the data will be placed correctly upon the paper in the "portrait" direction of feed by which is meant that the "11" inch direction or dimension is utilized.
A number of different interposing mechanisms have been suggested in the past, but each has had its own peculiar set of unwieldy conflicts or non-efficient aspects and limitations. Since it is desirable to keep the paper flow continuous, stop-start finger interposers are not acceptable. Neither are rotating fingers, since the space required by such a mechanism prevents the fingers from being positioned close enough to provide top efficiency of operation. Interference with the rotating drum surface is another problem which limits the closeness of the interposer to the transfer point, i.e., the point where the paper a actually meets the drum or printing device. Stopping and starting the paper for normal amounts of time would tend to cause the front edge of one sheet to crash into the rear edge of the sheet in front of this first sheet. Belts are inherently expensive to fabricate, maintain and utilize.
As seen in FIG. 3 of the drawings, the desired path for the interposer is not one easily obtained by conventional registration finger motion (i.e. rotating devices or fingers on a belt). However, by synthesizing an appropriate four-bar linkage the coupler curve can be used to provide the desired motion. The concept of a four-bar coupler curve interposer action represents a novel improvement over existing methods. The synthesis of such a mechanism produces a four-bar interposer linkage. Such interposer provides all the desirable features previously listed. Also, its speed can be tailored to provide the proper interception action and the dwell portion (beneath the paper path) can be designed so that the nose-to-tail distance (window) resulting between sheets is minimal, which is an important factor in throughput of cut sheet printers having a given print speed.
As noted by reference to FIG. 3, an acceptable maximum mechanism envelope has been previously calculated in order most efficiently to take advantage of the available non-interfering space between the paper feed mechanism and the photo-receptor drum. As previously stated, the interposer mechanism must be positioned as close to the transfer point as possible, (this point will be described in detail later on herein), to avoid timing problems associated with registering the sheet on the printing drum as well as to avoid the possibility of overlap or paper jams. Detailed description of the operational assembly performing the various functions will be discussed, first with respect to FIGS. 1 and 2.
The mechanical structure of the four-bar interposer apparatus 10 embodying the present invention is seen in FIG. 1 to include a vertical wall structure 12 of rigid material, such for example, as aluminum, etc. Two oppositely disposed tracks 14 and 16 form respectively, an entering sheet paper path from below and a return sheet paper "duplexer" path from above, as is described in more detail in copending U.S. application filed June 26, 1980, U.S. Ser. No. 163,394 in the name of Emmett B. Peter III entitled "Duplex Printing Paper Handling Mechanism for Cut Sheet Printing", assigned to the same assignee as the present invention. Cut sheet paper 18 is, or may be fed from a sheet hopper (not shown) into the nip between the drive and idler rollers 20 and 22 respectively, upwardly, FIG. 1, along track 14 to the nip of drive and idler rollers 24 and 26. Continued driven movement caused by these drive rollers of paper sheet 18 forces the paper to enter the nip between the drive and idler rollers 28 and 30 respectively, at which point passage of the paper 18 interrupts light passing across the paper path from the jam detector photo diode 32 to the output receiving signal generating detector 34.
Because the paper transport and feed apparatus are inherently not too accurate, it becomes necessary to provide some means of registering the paper sheet so that it is located immediately before the photo-receptor drum 36, thus insuring that the printed indicia (intelligence-data) will be properly and accurately placed on the paper as the paper is passed around the photo-receptor drum surface 38. Since stopping and starting the paper 18 creates more problems than it solves, the paper is slowed in forward movement to coincide with the rotative movement of the drum in the direction of arrow 40. The timing involved is critical. The solution involves calculation of the desired path of the so-called interposing device or mechanism and synthesizing an appropriate "coupler curve" for a four-bar linkage with the coupler curve. The four-bar coupler curve interposer action represents a novel improvement over existing methods as will now be described.
As seen most clearly in FIGS. 1 and 2, a so-called four-bar interposer mechanism 50 is arranged beneath the upper and lower converging paper tracks 16 and 14 respectively. Mechanism 50, as shown, comprises a rotatable pulley wheel 52 provided with a peripheral timing notch 54 rotatable by means (not shown) counterclockwise (CC) in the direction of arrow 56 past a timing transducer, e.g. photo transistor 58, which is electrically interconnected to software (not shown) for precisely synchronizing the timing of the paper 18 advance and the imaging of the drive member 36.
Secured to pulley 52 at 180° in opposition to the transducer timing notch 54 is a pivot member 59 to which is rockably secured an irregularly shaped interposer link 60. The opposite free end of link 60 is arcuately shaped as to 62 for purposes to be described shortly herein. An interconnecting rocking link 64 (vertically disposed in FIG. 1) is pivotally mounted at one end 66 to the intermediate lower edge of link 60, while the opposite end of link 64 is rockably pivoted to the lower portion of wall member 12 as at 68.
Rotation of pulley 62 by means (not shown) in the direction of arrow 56 causes a clock timing pulse to be sent to the software main high resolution clock control circuitry (not shown) which enables the imaging of drum 36 and paper advance from the sheet hopper (not shown), in time synchronism to the movement of linkage 50. Arcuate movement of the end of link 60 carries the scoop-shaped end 62 first downwardly, FIG. 1, then leftwardly, thence upwardly into the position shown in FIG. 2. It is noted, although not shown in detail in the drawing, that the scoop-shaped nose portion 62 of member 60 passes into a slightly upwardly through 1n elongated slot 70 in the horizontal track portion 72 of the horizontal track forming members 74--74.
Thereafter, continued rotation of drum pulley 52 causes link 60 to move in its rightwardly raised condition along slot 70 to a position 76, FIG. 1, slightly beyond pretransfer rolls 42-44 and during this forward motion acts to slightly slow the inward egress of paper 18 from the higher speed rollers so that the forward movement of the paper tends to assume the rotative speed of drum 36 so that complete and accurate registration with the movement of drum 36 can be made. Thus, the registration of the intelligible data on the drum can be imprinted on the paper without fear of losing detail or of having only a portion of the data present on the paper after the paper has passed over and across the curved top surface of the drum.
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Non-impact offset printing apparatus providing repeatable top-to-bottom registration of printed matter transferred to cut sheet paper fed in the "portrait" direction by means of a timer-interposer mechanism which contacts the leading edge of each incoming sheet and times the entry of the sheet into the transfer point adjacent to the rim of the offset non-impact rotary printing apparatus effectively creating positive and accurate registration of all four margins of printed matter on each page.
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REFERENCE TO RELATED APPLICATION
This is a Continuation-In-Part application of PCT/EP2011/053397 filed Mar. 7, 2011. The subject matter of the aforementioned prior application is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method and to a device for producing tapering pipe sections on cylindrical pipes for ground screw foundations. Methods and devices for producing tapering, and more particularly conical sections on cylindrical, and notably metallic, pipes for the production of screw-in foundations used to mount components in the ground are known. The conical sections can be produced in a variety of ways, for example by welding together prefabricated shaped parts, or by hammering preferably seamless cylindrical pipes (see EP 1 105 597 B1). It is also possible to produce them by rolling preferably seamless pipes. The designs of the devices used for this purpose can thus vary accordingly.
However, the aforementioned methods are very complex. Production starting from prefabricated shaped parts, for example, requires a variety of steps (producing the shaped parts, for example by cutting, then bending and welding of the seams, and the like). Production processes based on hammering or rolling cylindrical pipes are not problematic as such, but are very complex in terms of the equipment that is required for the hammering or rolling device. The conventional hammering is associated with high wear and corresponding noise.
The objects are therefore to provide a method, by means of which such tapering sections can be produced on cylindrical pipes, or tapering sections can be produced from cylindrical pipes, for ground screw foundations in a simple and cost-effective manner, and to provide a device for carrying out such a method, which can be produced with reasonable complexity and which also allows for production of the ground screw foundations, which are economical and free of defects, requiring low personnel overhead. Tapering sections shall be considered to include all sections in which the cross-sectional shape or the diameter decreases. In pipes, a tapering section shall be considered to be in particular a section which is rotationally symmetrical relative to the longitudinal direction of the pipe, such as a conical section for example, which is to say a taper or a (truncated) cone, or a section having a curved, and more particularly a convex or concave, surface in the longitudinal direction of the pipe. Non-rotationally symmetrical sections, such as (truncated) cones having an elliptic base area or polygonal pyramids, and more particularly rectangular pyramids, are also tapering sections within the meaning of the invention.
SUMMARY OF THE INVENTION
According to the invention, the tapering pipe sections are produced by way of drawing preferably cylindrical, seamless pipes. The device according to the invention is used to carry out this method.
The deformation device comprises a working tool, which is composed of a variety of press roll disks or press roll disk segments. These are disposed radially around a longitudinal axis of a holder for the cylindrical pipe that is to be drawn. In addition, they are disposed pivotably around shafts which extend transversely and tangentially relative to the longitudinal axis of the holder and are designed so that, with development, the outer circumferential surfaces thereof form a tapering shape, preferably a cone.
The device moreover comprises a drawing unit. This unit is used to draw the pipe and/or the working tool along the longitudinal axis so that relative movement is achieved between the pipe and the working tool, which causes the shaping outer circumferential surfaces of the press roll disks, or press roll disk segments, to roll on the pipe and thus, through the cooperation thereof, transfer the tapering, and more particularly the conical or semi-conical shaping of the development to the pipe. By a corresponding selection of the development curve of the press roll disks or press roll disk segments, a tapering section can be produced which can be substantially freely selected in terms of the contour or geometry thereof.
This procedure has considerable advantages, in particular over the production of corresponding tapering pipe sections by way of rolling, which is likewise conceivable. In particular, this eliminates the complex drive is required for the rolling device. This is particularly important because a variety of press roll disks, or press roll disk segments, are provided in the device according to the patent. So as to produce the required synchronization of the speed of the press roll disks, or press roll disk segments, during rolling, each disk would have to be driven. However, this requires a complex gearboxes, which would be almost impossible to accommodate in the necessary dimensions, and in any case would be extremely complex and costly in terms of the design. However, when drawing is selected as the working method, a drive for the press roll disks, or press roll disk segments, is not necessary, which in itself results in considerable reductions in the complexity. In particular, a configuration comprising segments allows a particularly stable and compact construction.
The relative movement between the working tool and the pipe that is to be drawn can be generated in a variety of ways. The working tool can be held in a stationary manner, and the pipe can be drawn by means of the drawing unit. Alternatively, the pipe can be held in a stationary manner by means of a retaining unit, and the working tool can be drawn by means of the drawing unit. Finally, it is even possible to move both the pipe and the working tool toward each other in the relative movement.
So as to ensure uniformity of the cylinder shape which is created during drawing, and notably so as to minimize burrs between the individual press roll disk impressions on the workpiece, according to the invention, the pipe, or the working tool, can be further rotated about the longitudinal axis thereof (the longitudinal axis of the holder, or of the tube) during drawing. For this purpose, the retaining and drawing unit can also be designed as a rotating unit, or the working tool can be rotatable.
The rotation of the pipe, or of the working tool, does not have to be a rotation of 360° C. A rotation by an angle alpha=360°/number of rolls×2 suffices to ensure overlapping working of the seams between the press roll disk or of burrs forming on the workpiece, and the rotation can be carried out in steps or in an oscillating manner.
The device comprises one or more clamping units for clamping the pipe so as to be able to hold, draw and optionally rotate the pipe.
The clamping units can be designed to be self-locking so that, during drawing, the retaining force thereof increases proportionally to the tensile loads that are applied.
So as to prevent the pipe or pipes from diverting from the longitudinal axis of the holder during the drawing operation, the drawing device is advantageously equipped with a linear guide for guiding the pipe or pipes and/or the retaining, drawing and rotating unit and/or the working tool along the longitudinal axis of the holder.
So as to ensure that the outer circumferential surfaces of the press roll disks, or press roll disk segments, are carried along in a shaping manner during drawing, they must be seated with a friction fit against the pipe that is to be drawn at the start of the drawing operation. For this purpose, the press roll disks, or press roll disk segments, are preloaded by at least one spring element, so that they are seated with friction fit under tension against the pipe inserted into the holder. This is achieved according to the invention as follows:
The press roll disks, or press roll disk segments, are preloaded by the at least one spring element so that they are in the position of the smallest cross-section of the development thereof. When a pipe, for the purpose of working the same, is inserted into the holder defined by the outer circumferential surfaces of the press roll disks, or press roll disk segments, it impinges on this smallest cross-section of the development. In the course of further insertion of the pipe into the working position, it pushes the press roll disks, or press roll disk segments, back against the force of the at least one spring element in the direction of the position of the largest cross-section (or the cross-section corresponding to the pipe cross-section) of the development of the outer circumferential surfaces of the disks or disk segments, this being the position in which working of the pipe starts, as a result of drawing the same in the opposite direction.
The spring element ensures, or the spring elements ensure, by way of the restoring force thereof directed in the working direction, not only that the plurality of outer circumferential surfaces of the press roll disks, or press roll disk segments, are in uniform contact against the pipe, but also that they support the drawing process with this force, to a certain degree.
It is, of course, also conceivable to design the device so that the cylindrical pipe is inserted into the device in the same direction in which it is drawn out during the work. This would have the advantage of avoiding reversing the direction between insertion and drawing of the pipe. However, the press roll disks, or press roll disk segments, would then have to be in an open position for insertion of the pipe, because otherwise the pipe could not be inserted. This precludes the option of holding the press rolls disks, or press roll disk segments, under preload during insertion of the pipe. So as to ensure that the press roll disks, or press roll disk segments, are carried along during drawing, the corresponding preload must be established after the pipe is inserted and the position in which working is to begin is reached. This solution thus requires a higher design complexity than the one described before.
The spring element can be, among other things, at least one gas spring or a controlled pneumatic cylinder.
While the spring elements, through the restoring force thereof, do to some extent ensure a uniform, synchronous development of the outer circumferential surfaces of the press roll disks, or press roll disk segments, on the pipe, and thus a desired accurate transfer of the size of the development to the pipe, it is nonetheless advisable that this be further ensured this by way of synchronized coupling of the press roll disks, or press roll disk segments.
According to the invention, this is done by providing toothing on the disks or disk segments. This toothing can, for example, be positioned in the vicinity of the outer circumferential edges. The coupling attained is thus not very complex in terms of the design, and notably is very direct, with little friction loss.
According to the invention, at least 18, preferably 24, and still more preferably 28, 32 or 36 press roll disks, or press roll disk segments, are provided. This large number of disks ensures exact, uniform working of the workpiece.
The key here is to avoid the formation of burrs on the taper to be formed. The outer circumferential surfaces of the press roll disks, or press roll disk segments, must thus seamlessly join one another in the development thereof. So as to ensure this, the disk edges are radially chamfered.
In order that the outer circumferential surfaces of the disks, or disk segments, form a taper that diminishes opposite to the working direction, in the development thereof, the surfaces must be tapered toward the cone point. In light of the large number of press roll disks, or press roll disk segments, which are provided according to the invention, they could potentially become so narrow toward the cone point that the stability which is required to absorb the high deformation pressures would be jeopardized. So as to counteract this, according to the invention, the number of disks involved in the deformation is decreased over the course of the deformation process toward increasingly smaller pipe diameters. This is assured by designing individual or groups of press roll disks, or press roll disk segments, so as to be radially disengageable in relation to the remaining press roll disks, or press roll disk segments, during the drawing of the pipe.
The press roll disks, or press roll disk segments, can be replaceable with disk sets having a different size, so as to produce tapering sections on cylindrical pipes having differing cross-sections using a drawing unit according to the invention.
This application is based on the assumption that a tapering section is normally produced in a single drawing operation. However, this may cause the device to reach the limits of the load capacity thereof, notably with particularly strong cylindrical pipes or with particularly strong deformations (high gradients of the tapering section to be formed). For such cases, according to the invention, the drawing unit is designed for multi-stage or multi-step drawing operations. This means that the desired shape, for example a cone, is not produced in one operation, but rather, in a first step, the pipe is initially inserted into the holder only over a portion of the section of the intended tapering deformation, and is drawn so that only a deformation smaller than the one which is ultimately intended is initially reached, and the pipe, in one or several further steps, is then inserted a little deeper into the holder each time, and is drawn until the desired net shape, for example a cone, has been produced.
Considering the manner of the configuration of the outer circumferential surfaces of the press roll disks, or press roll disk segments, the formation of burrs on the tapering section should be precluded, or should remain within a reasonable scope, because the outer circumferential surfaces seamlessly adjoin each other in the development, and therefore no room should exist for formation of burrs. In order to further ensure this, for example if the seamless adjoining of the outer circumferential surfaces should be adversely impacted, for example due to tool wear or other tolerances, and moreover in order to achieve uniformity of the outer contour in any case, a rotating unit may be further provided for rotating the pipe and/or the working tool around the longitudinal axis of the holder during the drawing operation, or between the multiple drawing steps of a multi-step drawing operation.
The invention further relates to a method for producing tapering sections on cylindrical pipes for ground screw foundations by way of drawing, by means of the hereinabove described device.
This method can, for example, also be designed so that the drawing operation is carried out in several stages or steps (multi-step). This is done by inserting the cylindrical pipe only part-way into the holder for the first drawing stage, then drawing it, and subsequently inserting it a little further into the holder for a second drawing stage, then drawing it, and finally, for example in a third drawing stage, inserting it entirely into the holder, then drawing it, so that in this step the outer circumferential surfaces of the press roll disks, or press roll disk segments, roll entirely on the pipe and completely transfer the shape of the development thereof to the pipe. For this purpose, a drawing unit which allows such multi-step drawing is to be provided.
The method may include rotating the pipe around the longitudinal axis thereof during drawing and/or between several consecutive drawing steps, for example in order to avoid the formation of burrs or so as to compensate for inaccuracies in the tapering section to be formed. The rotating device is provided for this purpose.
The method can further be designed so that the several drawing steps are applied consecutively, at differing points on the length of the cylindrical pipe, so as to generate several tapering sections having differing cross-sections and/or differing gradients on a cylindrical pipe. For this purpose, the drawing unit must support such a multi-step drawing operation, for example by way of adjustable cooperation between the drawing device and deformation unit, in such a manner that either several deformation units are arranged consecutively and the individual deformation units have different sets of press roll disks, or press roll disk segments, respectively, and the drawing unit feeds the pipe that is to be deformed to the respective deformation unit, or the drawing unit, and the press roll disks or segments cooperate so that the pipe that is to be deformed is consecutively fed to the regions of the press roll disks, or press roll disk segments, which correspond to the respective degree of deformation to be achieved.
The method for generating several tapering sections of differing cross-sections and/or differing gradients on a cylindrical pipe is thus also carried out with different sets of press roll disks, or press roll disk segments. For this purpose, it must be possible to replace sets of press roll disks, or press roll disk segments, of differing sizes between each other, unless a dedicated drawing unit is to be used for each size.
The invention further relates to a method of the type mentioned above for generating several tapering sections having differing cross-sections and/or differing gradients on cylindrical pipes of ground screw foundations, in which a first tapering section is produced on a pipe having a smaller pipe cross-section by means of a device according to the patent, and then a tapering section is produced on a cylindrical pipe having a larger pipe cross-section by means of a device according to the invention, wherein a cylindrical end region of the cylindrical pipe having the smaller pipe cross-section is introduced, into the end region of the cylindrical pipe having the larger cross-section that is to be deformed in a tapering manner, before or during the production of the tapering section on the cylindrical pipe having the larger cross-section, and is fixed there during the tapering deformation.
The invention moreover relates to a method of the type mentioned above, in which one of the end regions of a cylindrical pipe having a smaller pipe cross-section is introduced into the end region of cylindrical pipe having a larger cross-section that is to be deformed in a tapering manner, before or during the production of the tapering section on the cylindrical pipe having a larger cross-section, and is fixed there with press fitting during the tapering deformation of this end region, so as to generate a ground screw foundation from cylindrical pipes having differing cross-sections and at least one tapering section.
Lastly, the invention also relates to a ground screw foundation comprising at least one cylindrical pipe having at least one tapering section, produced by one of the aforementioned methods. A tapering section designed as a cone may have a constant cone angle, or several, different cone angles.
Using the drawing method according to the invention, ground screw foundations having tapering sections notably in the longitudinal direction of the ground screw foundation can be produced. In the production method according to the invention, the curve shape of the press roll disks, which is to say the development contour of the press roll disks, defines the engagement in the radial direction. The geometry of the ground screw foundation can thus be adapted to the respective application of the ground screw foundation by appropriately selecting the curve shape of every curve disk, which can essentially be freely selected.
The transitions between different tubular and tapering sections, and more particularly between the conical and cylindrical sections of the ground screw foundation, can be convexly or concavely tapering transition regions, or an edge or a bend. The lateral region of the ground screw foundation preferably transitions continuously, which is to say substantially without an edge, from a tubular or conical section into a convex or concave region. Both the convexity radius R and the concavity radius r of the tapering transition regions can be designed to be constant or variable. It is obvious to a person skilled in the art that, because of the technical circumstances, an edge will always have a certain small radius.
The different tubular and tapering sections and the transition regions can be combined in any arbitrary form for this purpose. In particular an S shape can be formed, in which a first tubular section transitions via a cone into a second tubular section. The transition regions between the cone and the tubular sections preferably have a concave or convex design. The length of the concave section may be designed infinitesimally smaller, so that the convex section transitions into a concave section in a reversal line extending around the ground screw foundation.
A ground screw foundation according to the invention has a single- or multi-piece design, and more particularly a two-piece design. In the case of a multi-piece design, the ground screw foundation preferably comprises several cylindrical sections, and the individual elements of the ground screw foundation are joined during the production method according to the invention by way of a press-fit connection, notably in a cylindrical section of the pipes.
In a further method step, this basic shape of a ground screw foundation can subsequently be provided with a screw helix and/or a tip. The tip can, for example, be produced by obliquely severing the lower end of the ground screw foundation or by way of forging. The screw helix is often welded to the basic shape.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail based on the drawings. In the drawings:
FIG. 1 : shows a perspective view of the device according to the invention for producing conical sections 1 on cylindrical pipes 2 of ground screw foundations by way of drawing;
FIG. 2 : is a different perspective view of the device according to the invention;
FIG. 2 a : is a different perspective view of the device according to the invention in which, in particular, the clamping unit ( 21 ) of the drawing and rotating unit ( 19 , 15 ) and the angle of rotation of the drawing unit are shown in more detail;
FIG. 3 : is a sectional view of the device according to the invention of FIGS. 1 and 2 , showing the cylindrical pipe 2 inserted into the holder 6 for working purposes;
FIG. 4 : is a sectional view of the device according to the invention of FIGS. 1 and 2 , showing the end phase of the conical working of the cylindrical pipe 2 ;
FIG. 5 : is the perspective view of a press roll disk segment 3 ;
FIG. 6 : is a sectional view of the device according to the invention;
FIG. 7 : is a top view of the device according to the invention comprising the press roll disks or press roll disk segments 3 ;
FIGS. 8 a to c : show three phases of the process of conically deforming a cylindrical pipe 2 ;
FIGS. 9 a to c : show three phases of the process of conically deforming a cylindrical pipe 2 having a larger cross-section 17 , and having an end region 19 that is to be conically deformed, into which the cylindrical end region 18 of a cylindrical pipe 2 which has a smaller cross-section and is provided with a conical section 1 is introduced and fixed, by way of press fitting, during the conical deformation of the pipe having the larger cross-section;
FIGS. 10 a to c : show three phases of the process of conically deforming a cylindrical pipe 2 having a larger cross-section 17 , and having an end region 19 that is to be conically deformed, into which one of the end regions of a cylindrical pipe 2 having a smaller cross-section 16 is introduced and fixed, by way of press fitting, during the conical deformation of the pipe having the larger cross-section 17 ;
FIG. 11 : shows the device according to the invention, comprising a working tool ( 3 ), a retaining unit ( 20 ) for the pipe ( 2 ) that is to be worked, and a drawing and rotating unit ( 10 , 15 ) having a linear guide ( 22 ) for the working tool ( 3 ) and/or the retaining unit ( 20 ) as well as a further retaining unit ( 20 a ) for a cylindrical pipe ( 2 ) having a smaller pipe cross-section ( 16 ), which can be introduced into the end region ( 19 ) of the pipe ( 2 ) having the larger cross-section ( 17 ) that is to be deformed, so as to be fixed on this pipe;
FIGS. 12 a to f : show six different basic shapes of a single-piece ground screw foundation according to the invention;
FIG. 13 : shows a single-piece ground screw foundation according to the invention;
FIGS. 14 a to x : show twenty-four different basic shapes of a two-piece ground screw foundation according to the invention; and
FIGS. 15 a and b : shows a two-piece ground screw foundation according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the device according to the invention for producing at least one conical section ( 1 ) on cylindrical pipes ( 2 ) of ground screw foundations by way of drawing. The device comprises a plurality of press roll disks or press roll disk segments ( 4 ), which are disposed radially around a longitudinal axis ( 5 ) of a holder ( 6 ) for the cylindrical pipe ( 2 ) that is to be drawn, and pivotably around shafts ( 7 ) extending transversely and tangentially relative to the longitudinal axis ( 5 ), and which are designed so that, with development, the outer circumferential surfaces ( 8 ) of the press roll disks or press roll disk segments ( 3 ) form a cone.
Also shown are spring elements ( 11 ) in the form of gas springs ( 12 ), by means of which the press roll disks or press roll disk segments ( 4 ) are preloaded.
In addition, a unit ( 10 ) for drawing and/or for rotating ( 15 ) the pipe ( 2 ) is shown, by means of which the pipe ( 2 ) can be drawn along the longitudinal axis ( 5 ) through the press roll disks or press roll disk segments ( 4 ), so that the conical section ( 1 ) can be formed by means of the outer circumferential surfaces ( 8 ) rolling on the pipe during drawing.
FIG. 2 shows a different perspective view of the device according to the invention of FIG. 1 . It differs from the representation of FIG. 1 in that only a single element ( 11 , 12 ) is shown in the place of the several spring elements ( 11 ) in the form of gas springs ( 12 ). Moreover, the toothing ( 13 ) is shown here, by means of which the press roll disk segments ( 4 ) are synchronously coupled to each other.
FIG. 2 a is a different perspective view of the device according to the invention of FIG. 2 , in which, in particular, the clamping unit ( 21 ) of the drawing and rotating unit ( 10 , 15 ) and the angle of rotation ( 23 ) of the drawing unit ( 15 ) are shown in more detail. In accordance with the formula alpha=360°/number of rolls×2, this angle of rotation ( 23 ) is established so as to allow for working burrs, which may be created between the effective regions of the press roll disks or press roll disk segments ( 4 ), at the smallest angle of rotation possible.
FIG. 3 shows a sectional view of the device according to the invention of FIGS. 1 and 2 , comprising press roll disk segments ( 4 ) which are disposed radially around a longitudinal axis ( 5 ) of a holder ( 6 ) for the cylindrical pipe ( 2 ) that is to be drawn, and pivotably around shafts ( 7 ) extending transversely and tangentially relative to the longitudinal axis ( 5 ), and which are designed so that, with development, the outer circumferential surfaces ( 8 ) of the disk segments ( 3 ) form a cone.
Also shown are spring elements ( 11 ) in the form of gas springs ( 12 ), by means of which the disks or disk segments ( 4 ) are preloaded.
In addition, the cylindrical pipe ( 2 ) that is to be worked and inserted into the holder ( 6 ) is shown in the position at the start of the working operation by way of drawing.
FIG. 4 shows a sectional view of the device according to the invention of FIGS. 1, 2 and 3 , comprising press roll disk segments ( 4 ) which are disposed radially around a longitudinal axis ( 5 ) of a holder ( 6 ) for the cylindrical pipe ( 2 ) that is to be drawn, and pivotably around shafts ( 7 ) extending transversely and tangentially relative to the longitudinal axis ( 5 ), and which are designed so that, with development, the outer circumferential surfaces ( 8 ) of the disk segments ( 3 ) form a cone.
Also shown are spring elements ( 11 ) in the form of gas springs ( 12 ), by means of which the disks or disk segments ( 4 ) are preloaded in accordance with the representation or the method step according to FIG. 3 .
In addition, the cylindrical pipe ( 2 ) that is to be worked and inserted into the holder ( 6 ) is shown in the position of the final phase of the working operation by way of drawing, which is to say having an already shaped conical section ( 1 ) in the form of a cone ( 9 ).
In addition, a unit ( 10 ) for drawing and rotating ( 15 ) the pipe ( 2 ) is shown cut in half, and by these means the pipe ( 2 ) was drawn along the longitudinal axis 5 through the press roll disk segments ( 4 ) so that the conical section ( 1 ) was formed by means of the outer circumferential surfaces ( 8 ) rolling on the pipe ( 2 ) during drawing.
FIG. 5 shows a perspective view of a press roll disk segment ( 4 ). It shows the shaft ( 7 ) of the segment and the outer circumferential surface ( 8 ) thereof, and moreover the toothing ( 13 ) in the edge region ( 14 ) of the disk ( 4 ). In addition, the chamfer is visible, which is used to ensure that the press roll disk segments ( 4 ), when installed, are clear of each other during development, while the pipe section ( 2 ) is deformed into the cone ( 9 ), and adjoin each other as seamlessly as possible so as to achieve a cone surface that is uniformly deformed and clean to as great an extent as possible.
FIG. 6 shows a top view of the device according to the invention. The press roll disk segments ( 4 ) and the outer circumferential surfaces ( 8 ) thereof can be seen. Also shown is the holder ( 6 ) for the pipe ( 2 ) that is to be worked and the longitudinal axis ( 5 ). Fastening bores for holding lugs for preload elements ( 11 , 12 ) for the disks or disk segments ( 4 ) are likewise shown.
FIG. 7 shows a top view of the device according to the invention. The press roll disk segments ( 4 ) and the outer circumferential surfaces ( 8 ) thereof can be seen. Also shown is the holder ( 6 ) for the pipe that is to be worked and the longitudinal axis ( 5 ). The toothing ( 13 ) of the press roll disk segments ( 4 ) provided at the disk edges ( 14 ) is also indicated. The thickness of the disks or disk segments ( 4 ) is such that, not only can the high deformation forces be transmitted, but the disks ( 4 ) are only just clear of each other at the smallest cone diameter, yet are seated against the cone surface over almost the entire circumferences thereof.
FIGS. 8 a to c show the process of conically deforming a cylindrical pipe ( 2 ) in three phases. The cylindrical pipe ( 2 ) here has already been provided with a conical section ( 1 ) (in an earlier operation). FIGS. 8 a to c show the process of further conically deforming the conical section ( 1 ) in three steps.
In FIG. 8 a , the pipe ( 2 ) that is to be deformed is inserted into the device so far that the smallest radius of press roll disk segments ( 4 ) comes in contact with the surface of the pipe ( 2 ) that is to be deformed, at exactly the point at which further deformation into a longer cone section ( 1 ) on the pipe ( 2 ) starts.
FIG. 8 b shows that the process for the further conification has already been half way completed. The final cone ( 1 ) that is to be attained is indicated by the dash-dotted line. And finally,
FIG. 8 c shows the state of conification in which the smallest conification diameter has been reached by way of the press roll disk segments ( 4 ) that formed this region of the smallest cone diameter, with the largest radii of press roll disk segments ( 4 ) located opposite each other.
FIGS. 9 a to c show three phases of producing a ground screw foundation having two conical sections ( 1 ) from cylindrical pipes ( 2 ) having differing cross-sections ( 16 , 17 ).
The figures show a cylindrical pipe ( 2 ) having a larger cross-section ( 17 ), which was introduced into the holder in the longitudinal axis ( 5 ) of the holder ( 6 ).
Also shown is a further cylindrical pipe ( 2 ) having a smaller pipe cross-section ( 16 ) and a conical section ( 1 ), the cylindrical end region ( 18 ) of the pipe being axially aligned with the end region ( 19 ) of the pipe having the larger cross-section ( 17 ), which is to be conically deformed, for the purpose of being introduced into this second end region.
Also shown are press roll disk elements ( 4 ), which are mounted pivotably on shafts ( 7 ), and the outer circumferential surfaces ( 8 ) thereof for generating a conical section 1 at the end region ( 19 ) of the pipe ( 2 ) having the larger pipe cross-section ( 17 ) which is to be conically deformed.
FIG. 9 a shows the device after inserting the cylindrical pipe ( 2 ) having the larger pipe cross-section ( 17 ), with the longitudinal axis ( 5 ) thereof in the holder ( 6 ). The pipe ( 2 ) and the press roll disk segments ( 4 ) are located in the open position, which is the position in which the working of the end region ( 19 ) which is to be conically deformed is to start, by way of drawing out the pipe ( 2 ) and roll-like rolling of the outer circumferential surfaces ( 8 ) of the press roll disk segments ( 4 ). The cylindrical end region ( 18 ) of the pipe ( 16 ) having the smaller pipe cross-section has not yet been introduced into the end region ( 19 ) of the pipe ( 17 ) having the larger pipe cross-section which is to be conically deformed.
FIG. 9 b shows the same device after insertion of the cylindrical end region ( 18 ) of the pipe ( 2 ) having the smaller pipe cross-section ( 16 ) into the end region ( 19 ) of the pipe ( 2 ) having the larger pipe cross-section ( 17 ), which is to be conically deformed. The cylindrical pipe ( 2 ) having the larger cross-section ( 17 ) in this illustration has already been drawn approximately half way. The deformation of the end region ( 19 ) of the pipe ( 2 ) having the larger pipe cross-section ( 17 ) which is to be conically deformed has already been partially completed.
FIG. 9 c shows the state at the end of the drawing and deformation process. The deformation of the end region ( 19 ) that is to be conically deformed is completed. The portion of the pipe ( 2 ) having the smaller cross-section ( 16 ), which has been inserted into the end region ( 19 ) of the pipe ( 2 ) having the larger cross-section ( 17 ), which is to be conically deformed, is fixed there by press fitting as a result of the conical deformation of the latter.
FIGS. 10 a to c show the same device and the same working steps of deforming an end region ( 19 ) of a cylindrical pipe ( 2 ) having a larger cross-section ( 17 ) and of integrally connecting a cylindrical pipe ( 2 ) having a smaller cross-section ( 16 ), the cylindrical end region 18 of which is introduced into the end region of the pipe ( 2 ) having the larger cross-section ( 17 ) which is to be conically deformed, and is fixed there with press fitting during the conical deformation of the end region 19 of the pipe having the larger cross-section 17 which is to be conically deformed, as is shown and described for FIGS. 9 a to c.
Thus, FIGS. 10 a to c differ from FIGS. 9 a to c only in that the cylindrical pipe ( 2 ) having the smaller cross-section ( 16 ) does not have a conical section ( 1 ), but instead has a substantially undeformed cylindrical shape. Substantially undeformed shall mean that a certain degree of deformation of the cylindrical pipe ( 2 ) having the smaller pipe cross-section ( 16 ) is produced only in the connecting region, in which the two pipe parts were formed together or pressed together with press fitting.
FIG. 11 shows a device according to the invention comprising a working tool ( 3 ) composed of press roll disk segments ( 4 ), which are arranged around the longitudinal axis ( 5 ) of the holder ( 6 ) on shafts ( 7 ). A cylindrical pipe ( 2 ) having a larger pipe cross-section ( 17 ) is located in the holder ( 6 ) in longitudinal alignment with the longitudinal axis ( 5 ) of the holder ( 6 ). The pipe is inserted into the holder ( 6 ) so far that the press roll disk segments ( 7 ) are in the largest open positions thereof, and are seated against the pipe for the conical deformation thereof. The pipe ( 2 ) is held in a stationary manner and in the longitudinal axis ( 5 ) of the holder ( 6 ) by a retaining unit ( 20 ), by means of a clamping unit ( 21 ), and potentially also rotated by the rotating unit ( 15 ) during working, and/or drawn by the drawing unit ( 10 ) with linear guidance by the linear guide ( 22 ).
The working tool ( 3 ) is in turn linearly guided along the longitudinal axis ( 5 ) of the holder ( 6 ) by means of the linear guide ( 22 ) and can be rotated by a rotating unit ( 15 ) and/or drawn by the drawing unit ( 10 ). This configuration includes the option of moving only the working tool ( 3 ) by way of the rotating and/or drawing unit ( 10 , 15 ), or of moving only the retaining unit ( 20 ) using the rotating and/or drawing unit ( 10 ), or moving both the working and the retaining units ( 3 , 20 ) relative to each other.
A cylindrical pipe ( 2 ) having a smaller pipe cross-section ( 16 ) is held by a further retaining unit ( 20 a ) comprising a clamping unit ( 21 a ) in alignment with the longitudinal axis ( 5 ) of the holder ( 6 ) and is guided along the longitudinal axis ( 5 ) of the holder ( 6 ) by means of the linear guide ( 22 ) so that it can be inserted into the end region ( 19 ) of the pipe ( 2 ) having the larger cross-section ( 17 ) which is to be conically deformed so as to be fixed to this pipe.
FIGS. 12 a to f show different embodiments of a single-piece basic ground screw foundation shape. FIG. 12 a shows a base body of a ground screw foundation having a cylindrical pipe section 2 , which transitions into a conically tapering pipe section 1 . The cylindrical pipe section 2 has an outside pipe diameter D at the larger cross-section 17 . A bend-shaped transition 24 , which is to say an edge, is formed between the cylindrical and conical pipe sections. The edge is shown by the peripheral line on the base body. In contrast, FIG. 12 b shows the transition by way of a tapering, convex region 25 . The lateral region of the basic ground screw foundation shape transitions continuously, which is to say essentially without an edge, from a cylindrical section 2 , via the convex transition region 25 , into the conical section 1 .
FIGS. 12 c to f have an S-shaped contour, which is to say the basic shape of the ground screw foundation has two cylindrical pipe sections 2 , 2 ′, between which a conical section 1 is formed. The second cylindrical pipe section 2 ′ has a diameter d. The transitions between the cylindrical sections 2 , 2 ′ and the conical section 1 are designed as bend-shaped transitions 24 , respectively, according to FIG. 12 c . In contrast, FIG. 12 d shows the transition between the cylindrical pipe section 2 and the conical pipe section 1 as a continuous, convex transition region 25 . The convex radius R is at least five times the pipe diameter D at the larger cross-section 17 of the cylindrical pipe 2 . According to FIG. 12 e , which shows a variant of the embodiment of FIG. 12 c , the transition between the conical section 1 and the cylindrical pipe section 2 ′ is designed as a concavely tapering transition region 26 . The embodiment according to FIG. 12 f has a convex transition 25 between the cylindrical pipe section 2 and the conical pipe section 1 , and a concave transition region 26 between the conical section 1 and the cylindrical pipe section 2 ′. With such an embodiment having at least one concave or a convex transition 25 , 26 , the conical section 1 can also be designed infinitesimally short, so that the length thereof moves toward zero and a continuous transition occurs from the convex region 25 into the concave region 26 .
FIG. 13 shows a single-piece base body of the ground screw foundation according to FIG. 12 f , which was produced by the method according to the invention and in which, in further method steps, a tip 27 is forged and a screw helix 28 is welded on the periphery.
FIGS. 14 a to x show the basic shapes of different two-piece ground screw foundations produced by a method according to the invention, wherein the basic shapes can essentially be produced by combining the single-piece variant of the basic shapes according to FIGS. 12 a to f . As is shown in FIGS. 9 a to c , the two elements of the two-piece design are joined between the cylindrical end region of the first pipe having the smaller pipe cross-section 18 and the conically deformed end region of the second pipe having the larger pipe cross-section 19 . A joining region, in which the two cylindrical pipes 2 are connected by way of press fit, is shown in detail A of FIG. 15 .
The embodiments according to FIGS. 14 a, b, g, h, m, n, s, t have two substantially tubular sections 2 , 2 ′ and have a conical section 1 ′ at the lower end. The remaining embodiments have three tubular sections 2 , 2 ′, 2 ″ and two conical sections 1 , 1 ′ arranged downstream between two tubular pipe sections 2 , 2 ′, 2 ″, respectively. The transitions between the individual sections are designed as a bend-shaped transition 24 , as a convex transition region 25 , or as a concave transition region 26 .
FIG. 15 a shows a two-piece basic shape according to FIG. 14 x , which in a further work step is provided with a tip 27 and a screw helix 28 , so that it can be used as a ground screw foundation.
FIG. 15 b shows the joining region in more detail, in which the two pipes 2 overlap.
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The invention relates to a method and device for producing conical sections in cylindrical pipes of screw-in foundations by drawing. The device comprises a plurality of press rolling disks (segments) disposed radially about a longitudinal axis of a receptacle for the cylindrical pipe to drawn, pivotable about axes extending transverse and tangential to the longitudinal axis and designed such that the outer circumferential surfaces of the press roller disks (segments) form a developed cone. The device further comprises a drawing die for drawing the pipe along the longitudinal axis through the press roller disks (segments), such that the conical section can be formed by means of the outer circumferential surfaces rolling on the pipe during drawing. Spring elements clamp the press roller disks (segments) against the pipe. A rotary device rotates the pipe for uniform processing thereof.
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“This application is a is a continuation of copending application No. 10/132,482 filed on Apr. 25, 2002, which a continuation of application Ser. No. 09/676,335 filed on Sep. 29, 2000 now U.S. Pat. No. 6,471,285, and claims the benefit of the filing date of both applications.”
FIELD OF THE INVENTION
The present invention relates generally to a structural reinforcement system for use in increasing the stiffness, strength, or durability of different portions of automotive or aerospace vehicles. More particularly, the present invention relates to structurally reinforced closed forms, such as a hydroform structure or hydroform rail, which utilizes an expandable and foamable material to cross-link, structurally adhere, and reinforce the form when the foamable material becomes chemically active and expands upon heating.
BACKGROUND OF THE INVENTION
Traditionally, closed form or hydroforming techniques are used to draw and shape metal tubes. Conventional hydroforming techniques often involve two steps: (1) placing the desired bends in the tube and (2) forming the tube to the desired configuration. Step 2 of this process usually requires placing a tubular member having an open bore in a mold and pinching off the ends of the tube. A pressurized liquid is then injected into the open bore, causing the tube to stretch and expand out against the mold.
The manufacturing advantages of the hydroforming process is that it allows formation of relatively long tubular structures having a seamless perimeter. This process eliminates the cost of welding, machining, or fastening operations often used to shape the part in the desired configuration. As a result, a hydroform or closed form structure very often has a high length to diameter ratio. For instance, a hydroform structure may have a length in excess of 15′ and a diameter ranging from approximately ¾″ to more than 12″. To this end, a further manufacturing process advantage of a hydroform structure is that it can exceed the length of other tubular members, such as torsion bars or tubular bars, formed using other processes.
Additionally, hydroforming processing creates complex structural shapes that typically include bends and contour changes. Often the number of bends and contour changes in a hydroformed bar are greater and more complex than those found in torsion bars or other tubular structures formed using different techniques.
Hydroform structures typically have a constant wall thickness prior to forming, and might develop strength differences at the site of bends or changes in contour, as well as at certain locations along a long tubular section. Thus, it is often desirable to reinforce closed form and hydroform sections to improve their structural stiffness, strength, and durability, particularly in automotive vehicle applications.
Traditional ways of reinforcing tubular structures such as hydroforms and other closed forms include sliding a metal sleeve inside the tube and welding the reinforcing member in place. However, because the hydroform often includes one or more bends or one or more changes in contour and/or diameter, it is often difficult to insert the sleeve into the hydroform at the precise location of the weak portion. Other techniques include reinforcing the hydroform from the outside by welding the sleeve onto the outside of the hydroform. However, hydroforms are often used in applications having very close tolerances, resulting in little or no clearance for an externally placed reinforcing member. Accordingly, exterior reinforcements are often not as effective as interior reinforcements.
Additionally, in many operations the weight of the tubular member is critical and must be kept low as possible. Thus, the use of an external sleeve adds unwanted weight to the tubular assembly. Still further, the welding operation tends to be labor intensive, time consuming and inexact, increasing the cost of forming the hydroform member and producing parts that have questionable reliability. Finally, these additional manufacturing steps and operations are often cumbersome and difficult to integrate into a final vehicle manufacturing process in that additional tooling would need to be developed by the manufacturer and assembly plant resources, labor, maintenance, and space would need to be dedicated and expensed by the vehicle manufacturer.
Accordingly, there is a need in industry and manufacturing operations for system, device, and method for reinforcing the weak areas of closed forms and other hydroform tubes without significantly increasing the weight and manufacturing complexity. In particular, there is a need for reinforcing a closed form or hydroform, which utilizes a plurality of members or pieces to achieve integrated reinforcement within the closed form since the contour or shape of typical tubes do not allow for placement of single piece reinforcement members. In this regard, the present invention addresses and overcomes the shortcomings found in the prior art by providing a multi-piece reinforcement system having at least two members capable of being nested together within a hydroform that may then be fixed in location through the use of a third member which serves as a locking and positioning member of the reinforcement system within the hydroform or other closed form. However, design of two nesting member could also create a lock mechanism. Structural reinforcement of the hydroform is achieved through activation by heat of an adhesive material disposed along at least two of the members, such a material would typically expand to contact a substrate surface and in doing so structurally adhere the multiple members to each other and the hydroform.
SUMMARY OF THE INVENTION
The invention relates to methods and systems for reinforcing a closed form or hydroform member. In one embodiment, the hydroform member includes an outer structural member having an open bore; and an expandable material or structural foam supported by the outer structural member. The expandable material extends along at least a portion of the length of the outer structural member, and may fill at least a portion of the length of the bore.
The expandable material is generally and preferably a heat-activated epoxy-based resin having foamable characteristics upon activation through the use of heat typically encountered in an e-coat or other automotive painting operation. As the foam is heated, it expands, cross-links, and structurally adheres to adjacent surfaces. Preferred structural foam materials are commercially available from L&L Products, Inc. of Romeo, Mich. under the designation L5204, L5206, L5207, L5208, or L5209. Generally speaking, these automotive vehicle applications may utilize technology and processes such as those disclosed in U.S. Pat. Nos. 4,922,596, 4,978,562, 5,124,186, and 5,884,960 and commonly owned, co-pending U.S. application Ser. Nos. 09/502,686 filed Feb. 11, 2000, 09/524,961 filed Mar. 14, 2000, and particularly, 09/459,756 filed Dec. 10, 1999, all of which are expressly incorporated by reference.
The system generally employs two or more members adapted for stiffening the structure to be reinforced and helping to redirect applied loads. In use, the members are inserted into a closed form, such as a hydroformed tube, with the heat activated bonding material serving as the load transferring and potentially energy absorbing medium. In a particularly preferred embodiment, at least two of the composite members are composed of an injection molded nylon carrier, an injection molded polymer, or a molded metal (such as aluminum, magnesium, and titanium, an alloy derived from the metals or a metallic foam derived from these metals or other metal foam) and it is at least partially coated with a bonding material on at least one of its sides, and in some instances on four or more sides. A preferred bonding medium is an epoxy-based resin, such as L5204, L5206, L5207, L5208 or L5209 structural foam commercially available from L & L Products, Inc. of Romeo, Mich. However, the third member which serves to lock and position the first two members could also utilize an adhesive material along its outer surface. In addition, it is contemplated that the member could comprise a nylon or other polymeric material as set forth in commonly owned U.S. Pat. No. 6,103,341, expressly incorporated by reference herein. Still further, the member adapted for stiffening the structure to be reinforced could comprise a stamped and formed cold-rolled steel, a stamped and formed high strength low alloy steel, a stamped and formed transformation induced plasticity (TRIP) steel, a roll formed cold rolled steel, a roll formed high strength low alloy steel, or a roll formed transformation induced plasticity (TRIP) steel. In essence, any material that is considered structural may be used in conjunction with the structural foam. The choice of the structural material used in conjunction with a structural foam or other bonding medium will be dictated by performance requirements and economics of a specific application.
Additional foamable or expandable materials that could be utilized in the present invention include other materials which are suitable as bonding or acoustic media and which may be heat activated foams which generally activate and expand to fill a desired cavity or occupy a desired space or function when exposed to temperatures typically encountered in automotive e-coat curing ovens and other paint operations ovens. Though other heat-activated materials are possible, a preferred heat activated material is an expandable or flowable polymeric formulation, and preferably one that can activate to foam, flow, adhere, or otherwise change states when exposed to the heating operation of a typical automotive assembly painting operation. For example, without limitation, in one embodiment, the polymeric foam is based on ethylene copolymer or terpolymer that may possess an alpha-olefin. As a copolymer or terpolymer, the polymer is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules. Examples of particularly preferred polymers include ethylene vinyl acetate, EPDM, or a mixture thereof. Without limitation, other examples of preferred foam formulation that are commercially available include polymer-based material commercially available from L&L Products, Inc. of Romeo, Mich., under the designations as L-2105, L-2100, L-7005 or L-2018, L-7101, L7102, L-2411, L-2420, L-4141, etc. and may comprise either open or closed cell polymeric base material.
Further, it is contemplated that if an acoustic material is used in conjunction with the present invention, when activated through the application of heat, it can also assist in the reduction of vibration and noise in the overall automotive body. In this regard, the now reinforced closed form or hydroform will have increased stiffness in the cross-members, which will reduce the natural frequency, measured in hertz that resonates through the automotive chassis and reduced acoustic transmission and the ability to block or absorb noise through the use of the conjunctive acoustic product. By increasing the stiffness and rigidity of the cross-members, the noise and frequency of the overall engine ride vibration that occurs from the operation of the vehicle can be reduced since a reduced frequency of noise and vibration will resonate through the chassis. Although the use of such vibration reducing materials or media can be utilized instead of, or in conjunction with, the structural expandable material, the preferred embodiment of the structural reinforcement system of the present invention utilizes the structurally reinforcing expandable material. Use of acoustic materials in conjunction with structural may provide additional structural improvement but primarily would be incorporated to improve NV H characteristics.
It is also contemplated that foamable or expandable material could be delivered and placed into contact with the member or hydroform, such as hydroform tube found in automotive applications, through a variety of delivery systems which include, but are not limited to, a mechanical snap fit assembly, extrusion techniques commonly known in the art as well as a mini-applicator technique as in accordance with the teachings of commonly owned U.S. Pat. No. 5,358,397 (“Apparatus For Extruding Flowable Materials”), hereby expressly incorporated by reference. In this non-limiting embodiment, the material or medium is at least partially coated with heat-activated polymer that could be structural or acoustic in nature. This preferably heat activated material can be snap-fit onto the chosen surface or substrate; placed into beads or pellets for placement along the chosen substrate or member by means of extrusion; placed along the substrate through the use of baffle technology; a die-cutting operation according to teachings that are well known in the art; pumpable application systems which could include the use of a baffle and bladder system; and sprayable applications.
In one embodiment, at least two members composed of an injection molded nylon are provided with a suitable amount of bonding or load transfer medium molded onto its sides in at least one location wherein each portion is smaller in diameter than a corresponding insertable opening in the form or tube to enable placement within a cavity defined within an automotive vehicle, such as portions of a hydrofrom tube section or other area or substrate found in an automotive vehicle which could benefit from the structural reinforcement characteristics found in the present invention. In this embodiment, a first portion corresponds to, and is insertably attached to an opening located within a lower portion of the hydroform tube section. A second portion is slideably engaged and affixed to an upper surface of the first portion. A third portion is then utilized to fixedly bridge the first and second portions together within the hydroform tube. It is contemplated that the bonding medium could be applied to a substrate in a variety of patterns, shapes, and thicknesses to accommodate the particular size, shape, and dimensions of the cavity corresponding to the chosen form or vehicle application. The expandable material or bonding medium is activated to accomplish expansion through the application of heat typically encountered in an automotive e-coat oven or other painting operation oven in the space defined between the plurality of members and the walls of the hydroform tube defining the cavity. The resulting structure includes the wall structure of the hydroform tube joined to the plurality of members with the aid of the structural foam.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims and drawings, of which the following is a brief description:
FIG. 1 is a perspective view of a hydroform structural reinforcement system in accordance with the teachings of the present invention.
FIG. 2 is an exploded section view of a portion of a hydroform tube described in FIG. 1, showing the position of the plurality of members and the expandable material in the uncured state.
FIG. 3 is a cutaway sectional view of a hydroform structural reinforcement system in accordance with the teachings of the present invention showing the plurality of members one of the members comprising the hydroform structural reinforcement system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a reinforced hydroform system 10 formed in accordance with the teachings of the present invention. The hydroform reinforcement system 10 imparts increased strength, stiffness, or durability to a structural member, and, thus, may be used in a variety of applications. For instance, the reinforced hydroform system 10 may be used as part of the frame or rail system for automobiles or building structures.
In a preferred embodiment, as in FIG. 2, the present invention comprises at least two members 12 , 13 composed of an injection molded polymer are provided with a suitable amount of an expandable material or load transfer medium 14 , 15 molded on its sides perhaps in a plurality of portions 16 wherein each portion 16 is smaller in diameter than a corresponding insertable opening in the form or tube 18 , for placement within a cavity defined within an automotive vehicle, such as portions of a hydrofrom tube section or other area or substrate found in an automotive vehicle which could benefit from the structural reinforcement characteristics found in the present invention. In this embodiment, a first portion 20 corresponds to, and is insertably attached to an opening located within a lower portion of the hydroform tube section. A second portion 22 is slideably engaged and affixed to an upper surface of the first portion. A third portion 24 is then utilized to fixedly bridge the first 20 and second 22 portions together within the hydroform tube. It is contemplated that the bonding medium 14 , 15 could be applied to a substrate in a variety of patterns, shapes, and thicknesses to accommodate the particular size, shape, and dimensions of the cavity corresponding to the chosen form or vehicle application. The expandable material or bonding medium 14 , 15 is activated to accomplish expansion through the application of heat typically encountered in an automotive e-coat oven or other heating operation in the space defined between the plurality of members and the walls of the hydroform tube defining the cavity. The resulting structure includes the wall structure of the hydroform tube joined to the plurality of members with the aid of the structural foam.
In this preferred embodiment, the first 20 and second 22 portions are nested together within the hydroform tube 18 with each having an application of the expandable material or bonding medium 14 , 15 . The third portion 24 is then insertably engaged through the hydroform tube 18 as shown in FIG. 2 to serve as a locking and positioning member of the reinforcement system within the hydroform or other closed form. Structural reinforcement of the hydroform tube 18 is achieved through activation by heat or some other activation stimulus applied to the structural material 14 , 15 disposed along at least first 20 and second 22 portions wherein the structural material 14 , 15 may expand and will structurally adhere the first 20 , second 22 , and third 24 portions to each other and the hydroform tube 18 .
It is contemplated that the structural material or bonding material 14 , 15 comprises a structural foam, which is preferably heat-activated and expands and cures upon heating, typically accomplished by gas release foaming coupled with a cross-linking chemical reaction. This structural foam is generally applied to the members 12 , 13 in a solid or semi-solid state. The structural foam may be applied to the outer surface of the members 12 , 13 in a fluid state using commonly known manufacturing techniques, wherein the structural foam is heated to a temperature that permits the structural foam to flow slightly to aid in substrate wetting. Upon curing the structural foam hardens and adheres to the outer surface of the member 12 , 13 . Alternatively, the structural foam may be applied to the members 12 , 13 as precast pellets, which are heated slightly to permit the pellets to bond to the outer surface of the members 12 , 13 . At this stage, the structural foam is heated just enough to cause the structural foam to flow slightly, but not enough to cause the structural foam to thermally expand. Additionally, the structural foam may also be applied by heat bonding/thermoforming or by co-extrusion. Note that other stimuli activated materials capable of bonding can be used, such as, without limitation, an encapsulated mixture of materials that, when activated by temperature, pressure, chemically, or other by other ambient conditions, will become chemically active. To this end, one aspect of the present invention is to facilitate a streamlined manufacturing process whereby the bonding material 14 , 15 can be placed along the members 12 , 13 in a desired configuration and inserted within the closed form or hydroform at a point before final assembly of the vehicle.
The bonding material that may have foamable characteristics is generally an epoxy-based material, but may include an ethylene copolymer or terpolymer, such as with an alpha-olefin. As a copolymer or terpolymer, the molecule is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules.
A number of epoxy-based structural reinforcing foams are known in the art and may also be used to produce the bonding material 14 of the present invention. A typical structural foam includes a polymeric base material, such as an epoxy resin or ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing agent and perhaps a curing agent and filler), typically expands and cures in a reliable and predictable manner upon the application of heat or another activation stimulus. The resulting material has a low density and sufficient stiffness to impart desired rigidity to a supported article. From a chemical standpoint for a thermally-activated material, the structural foam is usually initially processed as a thermoplastic material before curing. After curing, the structural foam typically becomes a thermoset material that is fixed and incapable of flowing.
An example of a preferred structural foam formulation is an epoxy-based material that may include polymer modificis such as an ethylene copolymer or terpolymer that is commercially available from L&L Products, Inc. of Romeo, Mich., under the designations L5206, L5207, L5208 and L5209. One advantage of the preferred structural foam materials over prior art materials is the preferred materials can be processed in several ways. Possible processing techniques for the preferred materials include injection molding, extrusion or extrusion with a mini-applicator extruder. This enables the creation of part designs that exceed the capability of most prior art materials.
While the preferred materials for fabricating the bonding material 14 have been disclosed, the material 14 can be formed of other materials provided that the material selected is heat-activated or otherwise activated by an ambient condition (e.g. moisture, pressure, time or the like) and expands in a predictable and reliable manner under appropriate conditions for the selected application. One such material is the epoxy based resin disclosed in U.S. patent application Ser. No. 09/268,810, the teachings of which are incorporated herein by reference, filed with the United States Patent and Trademark Office on Mar. 8, 1999 by the assignee of this application. Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, polyurethane materials with high glass transition temperatures, and mixtures or composites that may include even metallic foams such as an aluminum foam composition. See also, U.S. Pat. Nos. 5,766,719; 5,755,486; 5,575,526; 5,932,680 (incorporated herein by reference). In general, the desired characteristics of the structural foam 16 include high stiffness, high strength, high glass transition temperature (typically greater than 70 degrees Celsius), and good adhesion retention, particularly in the presence of corrosive or high humidity environments.
In applications where a heat activated, thermally expanding material is employed, an important consideration involved with the selection and formulation of the material comprising the structural foam is the temperature at which a material reaction or expansion, and possibly curing, will take place. For instance, in most applications, it is undesirable for the material to be active at room temperature or otherwise at the ambient temperature in a production line environment. More typically, the structural foam becomes reactive at higher processing temperatures, such as those encountered in an automobile assembly plant, when the foam is processed along with the automobile components at elevated temperatures or at higher applied energy levels. While temperatures encountered in an automobile assembly body shop ovens may be in the range of 148.89° C. to 204.44° C. (300° F. to 400° F.), and paint shop oven temps are commonly about 93.33° C. (215° F.) or higher. If needed, blowing agents activators can be incorporated into the composition to cause expansion at different temperatures outside the above ranges.
Generally, prior art expandable acoustic foams have a range of expansion ranging from approximately 100 to over 1000 percent. The level of expansion of the structural foam 16 may be increased to as high as 1500 percent or more, but is typically between 0% and 300%. In general, higher expansion will produce materials with lower strength and stiffness.
The hydroform reinforcement system 10 disclosed in the present invention may be used in a variety of applications where structural reinforcement is desired. The hydroform system 10 has particular application in those instances where the overall weight of the structure being reinforced is a critical factor. For instance, the hydroform system 10 may be used to increase the structural strength of aircraft frames, marine vehicles, automobile frames, building structures or other similar objects. In the embodiment disclosed the hydroform system 10 is used as part of an automobile frame to reinforce selected areas of the automobile frame or rails, and may also be utilized in conjunction with rockers, cross-members, chassis engine cradles, radiator/rad supports, and door impact bars in automotive vehicles.
As best illustrated in FIGS. 2 and 3, the hydroform reinforcement system 10 is suitable for placement within a frame portion of an automobile frame assembly. At least two members 12 composed of an injection molded polymer (or other material (e.g., metal) or composite) are provided with a suitable amount of an expandable material or load transfer medium 14 molded on its sides in a plurality of portions 16 wherein each portion 16 is smaller in diameter than a corresponding insertable opening in the form or tube 18 , for placement within a cavity defined within an automotive vehicle, such as portions of a hydroform tube section or other area or substrate found in an automotive vehicle which could benefit from the structural reinforcement characteristics found in the present invention. In this embodiment, a first portion 20 corresponds to, and is insertably attached to an opening located within a lower portion of the hydroform tube section. A second portion 22 is slideably engaged and affixed to an upper surface of the first portion. A third portion 24 is then utilized to fixedly bridge the first 20 and second 22 portions together within the hydroform tube. It will be appreciated that the hydroform reinforcement system 10 of the present invention may be used to reinforce other areas of an automobile frame or rocker assembly and the number of members 12 and placement of the expandable material 14 along the members 12 would be dictated by the shape and desired application.
Though other heat activated materials are possible, a preferred heat activated material is an expandable polymeric material, and preferably one that is foamable. A particularly preferred material is an epoxy-based structural foam. For example, without limitation, in one embodiment, the structural foam is an epoxy-based material that may include an ethylene copolymer or terpolymer.
A number of epoxy-based structural reinforcing foams are known in the art and may also be used to produce the structural foam. A typical structural foam includes a polymeric base material, such as an epoxy resin or ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing and curing agent), expands and cures in a reliable and predicable manner upon the application of heat or the occurrence of a particular ambient condition. From a chemical standpoint for a thermally-activated material, the structural foam is usually initially processed as a flowable thermoplastic material before curing. It will cross-link upon curing, which makes the material incapable of further flow.
Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, and polyurethane. See also, U.S. Pat. Nos. 5,266,133; 5,766,719; 5,755,486; 5,575,526; 5,932,680; and WO 00/27920 (PCT/US 99/24795) (all of which are expressly incorporated by reference). In general, the desired characteristics of the resulting material include relatively high glass transition point, and good environmental degradation resistance properties. In this manner, the material does not generally interfere with the materials systems employed by automobile manufacturers. Moreover, it will withstand the processing conditions typically encountered in the manufacture of a vehicle, such as the e-coat priming, cleaning and degreasing and other coating processes, as well as the painting operations encountered in final vehicle assembly.
In another embodiment, the material 14 is provided in an encapsulated or partially encapsulated form, which may comprise a pellet, which includes an expandable foamable material, encapsulated or partially encapsulated in an adhesive shell, which could then be attached to the members 12 in a desired configuration. An example of one such system is disclosed in commonly owned, co-pending U.S. application Ser. No. 09/524,298 (“Expandable Pre-Formed Plug”), hereby incorporated by reference. In addition, as discussed previously, preformed patterns may also be employed such as those made by extruding a sheet (having a flat or contoured surface) and then die cutting it according to a predetermined configuration.
The skilled artisan will appreciate that the system may be employed in combination with or as a component of a conventional sound blocking baffle, or a vehicle structural reinforcement system, such as is disclosed in commonly owned co-pending U.S. application Ser. Nos. 09/524,961 or 09/502,686 (hereby incorporated by reference).
A number of advantages are realized in accordance with the present invention, including, but not limited to, the ability to manufacture a structural reinforcement system for use in a hydroform or other closed form for delivery and assembly at a vehicle assembly plant without the need for application of pumpable products, wet chemical products, and multiple sets of tools, such as for other prior art.
The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.
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An structural reinforcement system for use with hydroforms and other closed forms having a plurality of members designed to be secured to a closed form, such as an hydroform tube used in automotive applications. A bonding material, such as an epoxy-based reinforcing foam, is disposed on at least a portion of the outer surface of each of the plurality of members. Once the system is attached to the closed form, the foam expands and cures during an automobile assembly operation, bonding the reinforcement system to the hydroform tube and the members. As a result, the reinforcement system provides enhanced load distribution over the vehicle frame without adding excessive weight and further serves to reduce noise and vibrational characteristics of the automotive vehicle.
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BACKGROUND OF THE INVENTION
1. Statement of the Technical Field
The present invention relates to the field of data visualization and more particularly, to tree-map visualization.
2. Description of the Related Art
As computer technology advances, computing systems have undertaken the management and processing of larger data systems. With data systems ranging from massive standalone databases to vast distributed networks, oftentimes the limiting factor in analyzing the state of a given system rests not with computing resources, but with the human operator. Specifically, though the computing system may aggregate vast quantities of data in near real-time, in the end, a human being must visualize the compilation of data to draw effective conclusions from the visualization. Yet, the ability of the end user to digest compiled information varies inversely with the amount of data presented to the end user. Where the amount of compiled data becomes excessive, it can be nearly impossible for a human being to adequately analyze the data.
In an effort to address the foregoing difficulties, tree-map visualization methods have been developed. Initially proposed by Brian Johnson and Ben Shneiderman in the seminal paper, Johnson et al., Tree - Maps: A Space - Filling Approach to the Visualization of Hierarchical Information Structures , Dept. of Computer Science & Human-interaction Laboratory (University of Maryland June 1991), tree-map visualization techniques map “hierarchical information to a rectangular 2-D display in a space-filling manner” in which the entirety of a designated display space is utilized. Additionally, “[i]nteractive control allows users to specify the presentation of both structural (depth bounds, etc.) and content (display properties such as color mappings) information.”
Notably, tree-map visualization techniques can be compared in a contrasting manner to traditional static methods of displaying hierarchically structured information. According to conventional static methods, a substantial portion of hierarchical information can be hidden from user view to accommodate the view of the hierarchy itself. Alternatively, the entire hierarchy can be visually represented, albeit vast amounts of display space can be obscured, hence wasted simply to accommodate the structure without regard to the hierarchical data in the hierarchy itself.
In the tree-map visualization technique, however, sections of the hierarchy containing more important information can be allocated more display space while portions of the hierarchy which are deemed less important to the specific task at hand can be allocated less space. More particularly, in operation tree-maps partition the display space into a collection of rectangular bounding boxes representing the tree structure. The drawing of nodes within the bounding boxes can be entirely dependent on the content of the nodes, and can be interactively controlled. Since the display size is user controlled, the drawing size of each node varies inversely with the size of the tree, for instance the number of nodes. Thus, trees having many nodes can be displayed and manipulated in a fixed display space, yet still be visible even when dealing with 1 million objects.
To date, the tree-map visualization technique has been limited to displaying strictly hierarchical data. This is a significant limitation that impedes the usefulness of the tree-map in many circumstances. For example, where a tree-map is used to visualize a system of servers for many different business processes in a single company, a particular server can support several of the business process. Thus, the server cannot be viewed as belonging to a single parent business process. In a conventional tree map, the server simply would be visually replicated in the bounding box for each business process. In such a case, however, it will not be apparent to the user that the server in one bounding box is the same server that is represented in one or more other bounding boxes in the tree-map.
SUMMARY OF THE INVENTION
The present invention is a system, method and apparatus for presenting multi-ownership in a tree-map. The method can include detecting a proximity event about a representation for a node in the tree-map and determining through the representation a unique identifier for the node. All other representations in the tree-map can be located which corresponding to the unique identifier. Consequently, each of the representations can be highlighted in the tree-map. In this regard, the step of highlighting can include displaying a call-out box for each of the representations. Moreover, the detecting step can include receiving either a mouse-over event or a mouse-click event in either an event handler for the tree-map or in an event handler for the representation about which the proximity event is detected.
A multi-ownership tree-map visualization system can include a tree-map configured to visualize a set of interrelated nodes in which at least one individual node in the set is related to at least two parent nodes in the set. The system further can include an event handler programmed to process a proximity event associated with a specific portion of the tree-map by highlighting multiple portions of the tree-map in which the portions represent a single node in the set. In this regard, the proximity event can include a mouse-over event, a mouse-click event, or a keyboard selection event, to name a few. The system yet further can include logic for displaying a call-out box for each portion of the tree-map associated with the single node in the set. Each call-out box also can display properties specific to the node, such as a label, as well as properties that are specific to the node's parent such as priority.
BRIEF DESCRIPTION OF THE DRAWINGS
There are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
FIG. 1 is pictorial illustration of a multi-ownership tree-map visualization which has been configured in accordance with the inventive arrangements;
FIG. 2 is a schematic illustration of a tree-map visualization system which has been configured with the multi-ownership tree-map visualization of FIG. 1 ; and,
FIG. 3 is a flow chart illustrating a process for handling multi-ownership in the tree-map visualization system of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a system, method and apparatus for displaying multi-ownership in a tree-map visualization. Multi-ownership, as used herein, refers to the circumstance where a node within a set of nodes is represented among multiple parent nodes, multiple child nodes, or both multiple parent and child nodes. In this regard, multi-ownership does not comport strictly with a hierarchical structure. In accordance with the inventive arrangements, each node in the set of nodes can include a unique identifier. Whenever a node in the tree-map receives interest, such as when a mouse pointer passes in proximity to the node of interest, all other nodes in the tree-map which include the same unique identifier as the node of interest can be highlighted as can the node of interest. In this way, multi-ownership of the node of interest can be visually recognized by one observing the tree-map of the present invention.
FIG. 1 is pictorial illustration of a multi-ownership tree-map visualization which has been configured in accordance with the inventive arrangements. The tree-map 100 can include a multiplicity of nested nodes 110 , 120 , 130 , 140 , 150 , which can include a composition of one or more additionally nested nodes, such as the nodes 160 , 170 . As it is well-known in the art, a hierarchy of nodes can be displayed in tree-map form, although each node within the tree map is considered to be unique and independent. In this regard, it will not be apparent from the tree-map visualization where multiple representations of the same node occur within the tree map.
In the present invention, however, as shown in FIG. 1 , where the nested node 160 is the same representation of a node as the node 170 , one viewing the tree-map 100 can recognize the identity in multiple parent nodes 120 , 140 through the highlighting of nodes 160 , 170 , and in the concurrent display of the identity in one or more call-out boxes 190 A, 190 B. More particularly, as a mouse pointer 180 passes within proximity to the node 160 , not only can node 160 be highlighted and the call-out box 190 A overlain about the node 160 , but also node 170 can be highlighted and the call-out box 190 B can be overlain about the node 170 within the parent node 140 conveying to the user that node 160 and node 170 are the same node. Furthermore, though not illustrated specifically in FIG. 1 , the call-out boxes 190 A, 190 B could each convey a consistent label about the nodes 160 , 170 , or each one of the call-out boxes 190 A, 190 B could convey other information that may be influenced by the bounding boxes 120 , 140 . More particularly, call-out boxes can display properties specific to the node (as in the case of call-out box 190 B), such as a label, as well as properties that are specific to the node's parent such as priority (as in the case of call-out box 190 A).
Importantly, one skilled in the art will recognize that the invention is not merely limited to equating nodes 160 , 170 on an identity basis. Rather, the skilled artisan will also recognize that other types of firmly established relationships can be visualized in accordance with the multi-ownership visualization technique of the present invention. To that end, where common characteristics of nodes are shared among multiple nodes, highlighting and call-out boxes can be overlain about the multiple nodes in the tree-map. Hence, the relationship between nodes based upon which the unique identifier can be assigned is limited only by the types of relationships which can be established between nodes and their underlying representative entity.
FIG. 2 is a schematic illustration of a tree-map visualization system which has been configured with the multi-ownership tree-map visualization of FIG. 1 . The system can include a set of nodes 210 arranged in a hierarchy in which multiple nodes incorporate common nodes among one another. Each node can include a unique identifier 220 . A tree-map population process 230 can process the set of nodes 210 into a tree-map 100 . Importantly, though any one node 210 having a unique identifier can be represented by multiple locations within the tree-map 100 , in consequence of the unique identifier 220 , it can be determined in which multiple locations of the tree-map 100 the one node 210 can be located.
The system further can include an event handler 250 programmed to process operating system events received through a user interface 260 to the tree-map 100 . Specifically, operating system events such as mouse movements, keyboard strikes and mouse clicks can be received in the user interface 260 and routed to the event handler 250 . The event handler 250 can determine when the received operating system event should be interpreted as a request to identify an underlying node in the tree-map 100 . To that end, the operating system event can range from a simple mouse click upon a portion of the tree-map corresponding to the node, to a mouse-over event in which the mouse pointer passes over the portion of the tree-map corresponding to node.
In any case, responsive to the receipt of such an event, the identity of the underlying node associated with the portion of the tree-map 100 can be presented through the user interface 260 . For instance, a call-out box can be displayed in a similar manner to a tool-tip in which the identity of the node and ancillary data can be displayed. Significantly, in addition to displaying the call-out box, the tree-map 100 can be searched for other nodes 210 sharing the same unique identifier 220 as the node in the call-out box. For each found node, an additional call-out box or other presentation element can display or otherwise present the identity of the found node and any ancillary data which may be specific to the sub-hierarchy in which the other nodes 210 can be located. In this way, all portions of the tree-map 100 containing the same node 210 can be displayed concurrently through the user interface 260 .
FIG. 3 is a flow chart illustrating a process for handling multi-ownership in the tree-map visualization system of FIG. 2 . In step 310 , a proximity event can be received in an event handler. The proximity event can include, but is not limited to mouse and keyboard induced movements which are proximate to a region of a tree-map representing an underlying node. In block 320 , the underlying node can be identified. In block 330 , the unique identifier for the underlying node can be extracted and in block 340 , the tree-map can be searched for nodes sharing the same unique identifier.
In respect to the underlying node, the instance of the node can be highlighted in the tree-map. Specifically, a call-out box containing data for the underlying node such as a description or node name can be displayed, audibly spoken or presented using any other common user interface presentation manner. If in decision block 360 no other nodes in the tree-map share the same unique identifier, in block 380 the process can end. Importantly, however, if other nodes displayed in the tree-map share the same unique identifier, it can be presumed that the same node is represented in multiple portions of the tree map. Consequently, in block 370 , the other instances of the node can be highlighted and have call-out boxes overlain concurrently with the highlighting of the primary instance of the node.
The present invention can be realized in hardware, software, or a combination of hardware and software. An implementation of the method and system of the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein.
A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computer system is able to carry out these methods. Alternatively, the present invention can be included as part of an electronically distributable user-interface such as those commonly encountered over the global Internet in the form of renderable markup language documents.
Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.
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A multi-ownership tree-map visualization system can include a tree-map configured to visualize a set of interrelated nodes in which at least one individual node in the set is related to at least two parent nodes in the set. The system further can include an event handler programmed to process a proximity event associated with a specific portion of the tree-map by highlighting multiple portions of the tree-map in which the portions represent a single node in the set. In this regard, the proximity event can include a mouse-over event, a mouse-click event, or a keyboard selection event, to name a few. The system yet further can include logic for displaying a call-out box for each portion of the tree-map associated with the single node in the set.
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RELATED APPLICATION
[0001] This application (and any resulting patent) is a continuation of and claims priority from pending U.S. patent application Ser. No. 13/763,703 of the same title, filed 2 Feb. 2013 (attorney docket no. UWK-7000-UT); which claims the benefit of and priority to U.S. provisional patent application Ser. No. 61/597,699 of the same title, filed 10 Feb. 2012 (attorney docket no. UWK-7000-PV), the content of which is hereby incorporated by reference in its entirety for any and all purposes.
TECHNICAL FIELD
[0002] This invention relates to improved, ergonomically designed clothing hangers.
BACKGROUND OF THE INVENTION
[0003] Clothing hangers are well known and widely used, and numerous designs have appeared over time. Despite their ubiquity, clothing hangers are difficult to comfortably grasp, particularly when used to hang heavy garments or when carrying several clothing-laden hangers together. This is because when clothes are hung on a conventional clothing hanger (a wire-based example of which is shown in FIG. 1( a ) ), only the hook or suspension portion ( 10 ) is available to be grasped. While the hook or suspension portion ( 10 ) is effective for suspending the hanger ( 1 ) from, for example, a closet rod, it is not well designed for grasping by two or more fingers. The present invention solves this long-standing design flaw by providing clothing hangers in which the hook or suspension portion ( 10 ) incorporates features adapted for being grasped by two or more human fingers.
SUMMARY OF THE INVENTION
[0004] The ergonomic clothing hangers of the invention comprise a hook or suspension portion that, when viewed from the side, comprises at least two, preferably linearly arrayed and preferably arcuate, finger-engaging regions at least one, and preferably all, of which, are adapted to ergonomically engage an adult human finger. The hangers of the invention each further include a connector portion that connects the hook or suspension portion to the clothing support portion of the clothing hanger.
[0005] In preferred embodiments, the hangers of the invention are substantially planar and have suspension portions that comprise first, second, and third, or first, second, third, and fourth, linearly arrayed finger-engaging regions each adapted to ergonomically engage an adult human finger (preferably by having an arcuate or curved profile). In many preferred embodiments, one of the finger-engaging regions is also adapted for secure hanging association with a closet rod of substantially circular or ovoid cross-section, although finger-engaging regions, or suspension regions interspersed between finger-engaging regions, adapted for suspension from a closet rod of any particular geometric cross-section (e.g., ovoid, circular, or polygonal) are also within the scope of the invention.
[0006] These and other aspects and embodiments of the invention are discussed in greater detail in the sections that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows two side-view illustrations, (a) and (b), of conventional clothing hangers. The illustration in FIG. 1( a ) depicts a wire clothing hanger, while that in FIG. 1( b ) depicts a clothing hanger formed from plastic.
[0008] FIG. 2 shows two side-view illustrations, (a) and (b), of clothing hangers according to the invention. The illustration in FIG. 2( a ) depicts a hanger having a suspension portion ( 10 ) with two curved finger-engaging regions ( 11 , 12 ). The illustration in FIG. 2( b ) depicts a hanger having a suspension portion ( 10 ) with three curved finger-engaging regions ( 11 , 12 , 13 ).
[0009] FIG. 3 shows four side-view illustrations, (a)-(d), of representative hook or suspension portions ( 10 ) of clothing hangers according to the invention (connector and clothing support portions ( 50 , 100 ) are not shown).
[0010] FIG. 4 shows two representative embodiments, depicted in panels (a) and (b). Each panel contains a side view and a cross-section of a hook or suspension portion ( 10 ) of a hanger of the invention.
[0011] FIG. 5 shows three representative embodiments, depicted in panels (a), (b), and (c). Each panel contains a side view and a top view (from above) of a hook or suspension portion ( 10 ) of a hanger of the invention.
DETAILED DESCRIPTION
[0012] In the drawings, features common among clothing hangers may be commonly designated. A clothing hanger ( 1 ) includes a hook or suspension portion ( 10 ) connected to the clothing support portion ( 100 ) via a connector portion ( 50 ). The clothing support portion ( 100 ) can have any desired shape and configuration, whether now known or later developed. Indeed, a multitude of such shapes and configurations are known due to the tremendous variety of clothing types stored by hanging, including coats, pants, and jackets. For example, the clothing support portion can have a pair of downwardly inclined members, the distal ends of which may or may not be connected via a support member. As will be appreciated, support members, when present, can be used to hang coats, pants, and/or shirts, for example. In other embodiments, the clothing support portion of a hanger may be flat or straight, and may be comprises of one or more pieces. For example, in some embodiments wherein the clothing support portion is flat, it is comprised of two opposing pieces connected via a spring mechanism than allows a garment to be clasped there between.
[0013] As will be appreciated, any now known or later developed clothing support portions and/or connector portions can be adapted for combination with an ergonomic hook suspension portion ( 10 ). Generally, the hook or suspension portion ( 10 ) and connector region ( 50 ) are designed to connect to the clothing support portion ( 100 ) so that the hanger will, when loaded with one or more articles of clothing, hang in a balanced way when suspended from a closet rod, coat hook, cable, or the like.
[0014] Moreover, the hangers of the invention can be manufactured from any suitable material, or combination of materials. Suitable materials include metal wire and plastics or other polymeric materials that can be readily formed into desired shapes and configurations. Plastics are particularly preferred, as various widely available manufacturing processes, including injection molding and extrusion.
[0015] Turning now to the drawings, FIG. 2( a ) shows a clothing hanger ( 1 ) according to the invention that comprises a suspension portion ( 10 ) connected via a connector portion ( 50 ) to a clothing support portion ( 100 ). The suspension portion ( 1 ) is preferably substantially planar and, as shown in the embodiment shown in FIG. 2( a ) , includes at least two finger-engaging regions ( 11 , 12 ) in a linear array (i.e., adjacently positioned).
[0016] FIG. 2( b ) shows an alternative hanger embodiment wherein the hook ( 10 ) includes three arcuate or curved regions ( 11 , 12 , 13 ) in a linear array. In these and other embodiments of the invention, each of the finger-engaging regions (e.g., 11 , 12 , and/or 13 ) are arcuate or curved or otherwise ergonomically shaped to fit an adult human finger (typically an index, middle, or ring finger), although the invention also envisions embodiments where at least one, but fewer than all, of the finger-engaging regions has ergonomically adapted dimensions and curvature to be comfortably held by an adult human finger.
[0017] FIG. 3( a ) shows an embodiment wherein the hook ( 10 ) includes three linearly arrayed finger-engaging regions ( 11 , 20 , 13 ), wherein the central finger-engaging region ( 20 ) is of a size and shape that substantially complements the outer diameter of a closet rod ( 30 ) having a circular cross section. For example, standard wooden or metal closet rods in the United States have a diameter of about 1.25 inches, although closet rods of numerous cross-sectional shapes and sizes exist. As will be appreciated, the region of the suspension portion of a clothing hanger according to the invention intended to engage a closet rod can be manufactured to fit any desired closet rod shape and/or size. Indeed, the invention envisions kits that comprise a hanger of the invention and one or more adapter pieces that can be associated with the suspension portion of the hanger in order to accommodate closet or hanger rods of different shapes and/or sizes.
[0018] FIG. 3( b ) shows an embodiment wherein the hook ( 10 ) includes two arcuate finger-engaging regions ( 11 , 12 ) interspersed with an engaging element ( 21 ) designed to engage a closet rod ( 31 ) having a rectangular cross-section. In this embodiment, the engaging element ( 21 ) is not optimized for engaging a human finger.
[0019] FIG. 3( c ) shows an embodiment wherein the hook ( 10 ) includes three linearly arrayed finger-engaging regions ( 15 , 11 , 16 ), wherein the central finger-engaging region ( 11 ) is arcuate and is bounded on either side by finger-engaging regions ( 15 , 16 ) that have substantially planar surfaces in the areas intended to contact fingers. The central region ( 11 ) is of a size and shape that substantially complements the outer diameter of a closet rod (not shown) having a circular cross section.
[0020] FIG. 3( d ) shows an embodiment wherein the hook ( 10 ) includes four linearly arrayed, arcuate finger-engaging regions ( 11 , 12 , 13 , 14 ).
[0021] Those in the art will appreciate that the clothing hangers of the invention provide improved ergonomics as compared to conventional clothing hangers. Preferably, some or all of the finger-engaging regions of the hook or suspension portion ( 10 ) are configured to conform to the shape of an adult human finger that will engage that region when the hanger is being held or grasped by a person. In some embodiments, a finger-engaging region will have a curved or arcuate shape when viewed from the side. In some embodiments, including some having three linearly arrayed finger-engaging regions, at least one of the finger-engaging regions may be large enough to comfortably accommodate two (less preferably, three) fingers when grasped by a person carrying the hanger. The surface of the finger-engaging region intended for contact with a human finger (i.e., a “finger contact region”) preferably has an ergonomic shape or surface profile. FIGS. 4( a ) and (b) show two such shapes. FIG. 4( a ) shows a cross-section taken at the plane defined by A-A′ of the suspension portion ( 10 ) of a hanger of the invention having three finger-engaging regions ( 11 , 12 , 13 ), the center of which ( 12 ) is also intended to engage a closet rod (not shown) of circular or ovoid cross-section. In the depicted embodiment, the finger contact area ( 30 ) of the first finger-engaging region ( 11 ), which typically spans from a hanger hook's front face ( 41 ) to its rear face ( 42 ), has a slightly convex surface, whereas in the representative embodiment depicted in FIG. 4( b ) , the corresponding finger contact area ( 30 ) has a substantially planar surface. As will be appreciated, in some embodiments, each finger contact region of a particular hanger can have the same or substantially similar surface profile (e.g., a slightly convex or substantially planar surface), or the different finger contact regions can have different surface profiles. For example, in one embodiment wherein the suspension portion ( 10 ) has three adjacent finger-engaging regions, the finger contact region of each may be slightly convex. In a similar such embodiment, the three finger contact regions have substantially planar surfaces. In yet another similar such embodiment, the central finger contact region has a substantially planar surface (to promote stable closet rod engagement in addition to user comfort) while the finger contact regions on either side of the central finger contact region have slightly convex surface profiles.
[0022] For user comfort, the regions where the front or rear hook (or suspension portion) face meets the finger contact area of a finger-engaging region preferably provide for a smooth transition from one surface to the other, for example, through the use of a rounded, beveled, or otherwise tapered corner.
[0023] In some preferred embodiments, the front and/or rear face(s) ( 41 , 42 ) of the suspension portion ( 10 ) can also have a surface that includes one or more features adapted for comfortable, ergonomic engagement with those parts of a person's fingers that contact the those surfaces while the person is holding or grasping the hanger. FIG. 5 illustrates top views of three such representative ergonomic suspension portions ( 10 ) having three linearly arrayed finger-engaging regions ( 11 , 12 , 13 ). In the embodiment shown in FIG. 5( a ) , the front face ( 41 ) of the suspension portion ( 10 ) includes three convex indentations formed therein ( 43 , 44 , 45 ) to comfortably accommodate the distal portions of a user's fingers (not shown) or that part of the palm of a user's hand (not shown) adjacent to her/his that will engage the face during grasping. In the embodiment shown in FIG. 5( b ) , both the front and rear faces ( 41 , 42 ) of the suspension portion ( 10 ) have surfaces that include ergonomic features ( 43 , 44 , 45 , 43 ′, 44 ′ 45 ′) adapted to provide comfortable, ergonomic engagement with a person's fingers when grasping the hanger. Having the same ergonomic features on both the front and rear faces of the hook allow the hanger to be comfortably grasped by either a left or right hand regardless of whether the hanger is facing forward or backward. In contrast, the embodiment shown in FIG. 5( c ) has a suspension portion ( 10 ) wherein one face (e.g., the front face ( 41 )) includes convex indentations formed therein ( 43 , 44 , 45 ) accommodate the distal portions of a user's fingers (not shown), while the other face (e.g., the rear face ( 42 )) includes a single, large, slightly convex indentation ( 46 ) intended for engagement by the palm of the hand grasping the suspension portion ( 10 ) hanger.
[0024] The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Also, the invention illustratively described herein suitably may be practiced in the absence of any element(s) not specifically disclosed herein. Thus, for example, in each instance herein any of the terms “comprising”, “consisting essentially of”, and “consisting of” may be replaced with either of the other two terms. Furthermore, while the articles and methods of this 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 the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the spirit and scope of the invention. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
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The present invention relates to ergonomically designed clothing hangers adapted for ease of hand-carrying and hanging on a closet rod. These ergonomic hanger designs feature a rod hook or suspension portion that includes at least two, and preferably three, linearly arrayed curved regions each adapted to ergonomically engage an adult human finger. In this way, for example, the index, middle, and ring fingers of one hand of a person carrying the hanger can easily and comfortably grasp the hanger by the suspension portion. When simultaneously carrying one or several such clothing hangers loaded with clothes, the resultant load is better distributed across the person's hand, allowing for easier, more comfortable, and less fatiguing transportation of the clothing item(s) hanging on the hangers. In preferred embodiments, at least one of the curved regions (often the central or second region among three) is also adapted to conform to the outer dimension and shape of a closet rod.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for producing adamantyl (meth)acrylates having an adamantane skeleton, which are excellent in optical properties, heat resistance and acid dissociability and useful for crosslinked resins, optical fibers, optical waveguides, optical disc substrates, other optical materials such as photoresists and their starting materials, as well as for intermediates for medicines and agrochemical intermediates, and other various industrial products, etc.
2. Description of the Related Art
Adamantane has a rigid structure of high symmetricity and its derivatives show specific functions, and therefore, they are known to be useful for high-function resin materials, medicine intermediates, optical materials (see JP-B 1-53633 and JP-A 6-305044), photoresists (see JP-A 4-39665 and JP-A 2006-016379), etc.
BRIEF SUMMARY OF THE INVENTION
Of those adamantanes described in the above-mentioned patent publications, the adamantane derivatives described in JP-A 2006-016379 are obtained generally through (meth)acryl-esterification of the starting compound of adamantane-dialcohols. However, the present inventors have found the following problems with the method for producing adamantane derivatives described in the patent publication. Concretely, according to the method for producing adamantane derivatives described in the patent publication, the reaction product is a mixture of the starting compound, monoester and diester, and therefore, it is not easy to separate and purify the mixture. For the separation and purification, for example, employable is a method based on adsorption such as silica gel column purification, or any other known method of distillation, crystallization, etc.; however, industrial use of these methods is difficult because of the following reasons.
First, column purification may readily enable separation and purification, but in industrial-scale production, it has some disadvantages in that the production volume is small and the production cost is high. Regarding distillation purification, it is difficult to vaporize the compound by itself in an industrial-scale distillation method since the boiling point of the compound is high. Accordingly, crystallization could be only one industrially practicable purification method, which, however, is intrinsically problematic in that the crystallization is extremely difficult when the purity of the objective compound is low. Therefore, the intended compound must be sufficiently separated from the by-products before it is collected through crystallization. For these reasons, it is necessary to establish a production method suitable to industrial-scale production.
An object of the present invention is to provide an efficient production method suitable to industrial-scale production not requiring column purification for adamantyl (meth)acrylates having an adamantane skeleton and useful as monomers for use for resins excellent in optical properties, etc.
The present inventors have assiduously studied for the purpose of solving the above-mentioned problems and, as a result, have found that a mixture of compounds of formulae (2) to (4) can be efficiently separated according to the present invention mentioned below.
Specifically, the present invention is a method for producing adamantyl (meth)acrylates of formulae (3) and (4), comprising a reaction step of reacting a compound of formula (1) with a (meth)acryloyl halide or a (meth)acrylic anhydride in a reaction solution to give a mixture of compounds of formulae (2) to (4), and a separation step of separating the mixture of compounds of formulae (2) to (4); wherein the separation step comprises an extraction step of extracting compounds of formulae (2) and (3) from the reaction solution with a mixed solvent of water and a polar organic solvent, thereby giving a water/polar organic solvent solution containing the compounds of formulae (2) and (3) and the mixed solvent, and a back-extraction step of back-extracting the compound of formula (3) from the water/polar organic solvent solution with a non-polar organic solvent,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and Y 1 and Y 2 are the same or different, each representing a hydrogen atom, lithium, sodium, or a magnesium halide group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; and R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and R 5 represents a hydrogen atom or a methyl group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and R 5 and R 6 are the same or different, each representing a hydrogen atom or a methyl group.
The compounds of formulae (3) and (4) in the present invention and functional resin compositions starting from them have a hydrophobic alicyclic skeleton and are used for crosslinked resins, optical fibers, optical waveguides, optical disc substrates, other optical materials such as photoresists and their starting materials, and also for intermediates for medicines and agrochemical intermediates, and other various industrial products, etc. In particular, they have an acid-dissociable ester group and undergo large polarity change before and after dissociation at the acid-dissociable group thereof, therefore having a large dissolution contrast; and accordingly, they are useful as monomers for photoresists for KrF excimer laser, ArF excimer laser or F 2 excimer laser, or X-ray, EUV or electron-beam lithography. Above all, when incorporated in conventional ArF resist polymers, they enhance the contrast in microfabrication.
According to the present invention, there is provided an efficient production method suitable to industrial-scale production for adamantyl (meth)acrylates having an adamantane skeleton, excellent in optical properties, heat resistance and acid dissociability and useful for crosslinked resins, optical fibers, optical waveguides, optical disc substrates, other optical materials such as photoresists and their starting materials, as well as for intermediates for medicines and agrochemical intermediates, and various industrial products, etc.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter embodiments of the present invention will be described.
The present invention is a method of producing adamantyl (meth)acrylates of formulae (3) and (4), which comprises a reaction step of reacting a compound of formula (1) with a (meth)acryloyl halide or a (meth)acrylic anhydride in a reaction solution to give a mixture of compounds of formulae (2) to (4), and a separation step of separating the mixture of compounds of formulae (2) to (4). The separation step comprises an extraction step of extracting compounds of formulae (2) and (3) from the reaction solution with a mixed solvent of water and a polar organic solvent, thereby giving a water/polar organic solvent solution containing the compounds of formulae (2) and (3) and the mixed solvent, and a back-extraction step of back-extracting the compound of formula (3) from the water/polar organic solvent solution with a non-polar organic solvent.
The individual steps will be described in detail below.
[Reaction Step]
The reaction step is a step of reacting a compound of formula (1) with a (meth)acryloyl halide or a (meth)acrylic anhydride in a reaction solution to give a mixture of compounds of formulae (2) to (4). Specifically, a mixture of compounds of formulae (2) to (4) is produced in the reaction solution through esterification of an adamantane compound of formula (1) with a (meth)acrylic acid compound.
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and Y 1 and Y 2 are the same or different, each representing a hydrogen atom, lithium, sodium, or a magnesium halide group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; and R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and R 5 represents a hydrogen atom or a methyl group,
wherein X's are the same or different, each representing a hydrogen atom, an alkyl group, a halogen-containing alkyl group, a halogen group, a nitrile group, or an ether group; n indicates an integer of 14; R 1 to R 4 are the same or different, each representing an alkyl group or a halogen-containing alkyl group; and R 5 and R 6 are the same or different, each representing a hydrogen atom or a methyl group.
The reaction solution mainly contains an adamantane compound of formula (1), a (meth)acryloyl halide and/or a (meth)acrylic anhydride, and a solvent for their reaction.
The adamantane compound of formula (1) for use herein is generally a compound having two hydroxyl groups. The compound having two hydroxyl groups is represented by formula (1) where Y 1 and Y 2 are both hydrogen atoms. The hydroxyl group may be alcoholated with an alkali metal such as lithium or sodium, or an alkyl lithium such as butyllithium, or a Grignard reagent such as ethylmagnesium bromide or the like; and thereafter the resulting compound may be esterified with a (meth)acrylic acid compound. The alcoholate compound is represented by formula (1) wherein Y 1 and Y 2 are the same or different, each representing Li, Na, MgBr, MgCl, MgI, etc.
A compound produced through reaction of a 1,3-adamantane-dicarboxylic acid and an organic metal compound may also have a form of the above-mentioned alcoholate compound, and the compound of the type may be esterified directly with a (meth)acrylic acid compound.
A (meth)acrylic acid compound includes, for example, (meth)acryloyl halides, (meth)acrylic anhydrides, (meth)acrylic acids, (meth)acrylates, etc.; and in the present invention, used are a (meth)acryloyl halide and a (meth)acrylic anhydride or any one of these (hereinafter referred to as “(meth)acrylic acid compound”, if desired), as capable of producing compounds of formulae (3) and (4) at a high reaction yield. Concretely, the (meth)acryloyl halide includes acryloyl chloride and methacryloyl chloride. The (meth)acrylic anhydride includes methacrylic anhydride, acrylic anhydride, and methacrylic/acrylic anhydride. The amount of the (meth)acrylic acid compound may be from 0.5 to 10 equivalents relative to the adamantane compound of formula (1) (hereinafter this may be referred to as a starting compound), preferably from 0.7 to 3 equivalents (in this, one equivalent corresponds to the necessary acryloyloxy group). When the amount of the (meth)acrylic acid compound to be used is less than 0.5 equivalents, then the yield may lower; but when more than 10 equivalents, it is uneconomical.
For rapidly reacting the adamantane compound of formula (1) with the (meth)acrylic acid compound at a high yield, a base compound is preferably added to the starting compound. Adding the base compound promotes the reaction, therefore giving the intended substance at a higher yield. The base compound to be added is preferably an amine compound, as capable of giving compounds of formulae (3) and (4) at a high reaction yield. Examples of the amine compound include aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, di-iso-propylamine, tri-n-propylamine, n-butylamine, di-n-butylamine, di-iso-butylamine, tri-n-butylamine, diphenylamine, 1,5-diazabicyclo[4.3.0]nonene-5,1,5-diazabicyclo[5.4.0]undecene-5, diazabicyclo[2.2.2]octane; anilines such as aniline, methylaniline, dimethylaniline, toluidine, anisidine, chloroaniline, bromoaniline, nitroaniline, aminobenzoic acid; nitrogen-containing heterocyclic compounds such as pyridines, e.g., pyridine, dimethylaminopyridine, and pyrroles, quinolines, piperidines, etc.
As the base compound, also usable are metal alkoxides such as sodium methoxide, lithium methoxide; quaternary ammonium hydroxides such as tetramethylammonium hydroxide, trimethyl-n-propylammonium hydroxide; amine sulfates, nitrates and chlorides such as ethylammonium sulfate, trimethylammonium nitrate, anilinium chloride; inorganic bases such as sodium hydrogencarbonate; Grignard reagents such as ethylmagnesium bromide, in addition to the above-mentioned amine compounds.
Preferably, the amount of the base compound to be used is at most 10 equivalents relative to the starting compound. Even though the amount of the base compound used is more than 10 equivalents, the effect of the base compound added is no more enhanced. However, in case where the base compound is liquid, the compound itself may serve also as a solvent and therefore the amount of the base compound to be used is not limited. The method of adding the base compound is not specifically limited. The base compound may be previously fed into the reactor before a (meth)acrylic acid compound is put thereinto, or it may be fed into the reactor after a (meth)acrylic acid compound is put thereinto. The compound may be dropwise put into the reactor simultaneously with a (meth)acrylic acid compound thereinto. In this case, the system is preferably so controlled as to prevent the reaction temperature from rising abnormally, as capable of retarding the promotion of side reactions.
The solvent to be used in reacting the adamantane compound of formula (1) and a (meth)acrylic acid compound is preferably one in which the solubility of the starting compound and the intended product (adamantyl (meth)acrylates) is high. The solvent includes halogen compounds such as dichloromethane, chloroform, 1,2-dichloroethane; ether compounds such as tetrahydrofuran, diethyl ether, diisopropyl ether, di-n-propyl ether, di-n-butyl ether, methyl t-butyl ether, dioxane; aromatic compounds such as benzene, toluene, xylene, ethylbenzene, cumene, mesitylene, pseudocumene; aliphatic hydrocarbons having from 6 to 10 carbon atoms such as hexane, heptane, octane, nonane, decane; alicyclic hydrocarbons having from 6 to 10 carbon atoms such as cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane; nitrile compounds such as acetonitrile, benzonitrile; ester compounds such as ethyl formate, methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate; amides such as formamide, acetamide, dimethylformamide, dimethylacetamide, etc. The above-mentioned base compound may serve also as a solvent. One or more of those solvents may be used herein either singly or as a mixed system thereof. The amount of the solvent to be used may be in a ratio of from 0.1 to 20 parts by weight relative to 1 part by weight of the starting compound, preferably from 1 to 10 parts by weight.
The reaction temperature may be generally from −70° C. to 200° C., preferably from −50° C. to 80° C. When the reaction temperature is lower than −70° C., then the reaction speed may be low; but when higher than 200° C., then the reaction may be difficult to control or side reactions may go on to lower the yield. The reaction time for esterification in the present invention may be generally from 0.5 to 1000 hours, preferably from 1 to 100 hours. However, the reaction time depends on the reaction temperature and the esterification method, and is therefore determined in accordance with the intended yield; and accordingly, the reaction time is not limited to the above range.
In esterification reaction, a polymerization inhibitor may be added to the system. Not specifically limited, the polymerization inhibitor may be any ordinary one, including, for example, nitroso compounds such as 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl, N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine aluminium salt, N-nitroso-N-(1-naphthyl)hydroxylamine ammonium salt, N-nitrosodiphenylamine, N-nitroso-N-methylaniline, nitrosonaphthol, p-nitrosophenol, N,N′-dimethyl-p-nitrosoaniline; sulfur-containing compounds such as phenothiazine, methylene blue, 2-mercaptobenzimidazole; amines such as N,N′-diphenyl-p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, 4-hydroxydiphenylamine, aminophenol; quinones such as hydroxyquinoline, hydroquinone, methylhydroquinone, p-benzoquinone, hydroquinone monomethyl ether; phenols such as methoxyphenol, 2,4-dimethyl-6-t-butylphenol, catechol, 3-S-butylcatechol, 2,2-methylenebis-(6-t-butyl-4-methylphenol); imides such as N-hydroxyphthalimide; oximes such as cyclohexane oxime, p-quinone dioxime; dialkylthio dipropionates, etc. The amount of the polymerization inhibitor to be added may be from 0.001 part by weight to 10 parts by weight relative to 100 parts by weight of the (meth)acrylic acid compound, preferably from 0.01 part by weight to 1 part by weight.
After the reaction, the reaction liquid is washed with water to remove excessive (meth)acrylic acid compounds and additives such as acid and base. In this stage, the washing water may contain a suitable inorganic salt such as sodium chloride, sodium hydrogencarbonate, etc. The unreacted (meth)acrylic acid compounds are removed through washing with alkali. For the alkali washing, usable is an aqueous sodium hydroxide solution, a potassium hydroxide solution, aqueous ammonia or the like; but the alkali ingredient in the solution to be used is not specifically limited. For removing base and metal impurities, acid washing may be performed. For the acid washing, usable is an inorganic acid such as an aqueous hydrochloric acid solution, an aqueous sulfuric acid solution or an aqueous phosphoric acid solution, or an organic acid such as an aqueous oxalic acid solution, etc. In washing, an organic solvent may be added to the reaction solution, depending on the physical properties of the compounds of formulae (2) to (4). The organic solvent to be added may be the same as that used in the above-mentioned esterification reaction, or may be a different solvent.
Depending on the physical properties of the compound of formula (2), the compound may partly precipitate after the reaction or after the washing. In case where the compound precipitates after the reaction, the precipitate may be separated through filtration. Alternatively, a solvent capable of dissolving the compound of formula (2) may be added to the system and the washing treatment may be continued further. In case where the compound precipitates after the washing, the compound of formula (2) may be separated through filtration, or may be dissolved in the solvent used in the extraction step to be mentioned later.
[Separation Step]
The separation step is a step of separating a mixture of the compounds of formulae (2) to (4). The separation step comprises the following extraction step and back-extraction step.
(Extraction Step)
The organic layer after the washing contains a mixture of the compounds of formulae (2) to (4). First, the compounds of formulae (2) and (3) are separated from the compound of formula (4) through solvent extraction. As the solvent for extraction, used is a water/polar organic solvent. The water/polar organic solvent means a mixed solvent of water and a polar organic solvent. When such a water/polar organic solvent is used, then the compounds of formulae (2) and (3) are extracted into the water/polar organic solvent, thereby giving a water/polar organic solvent solution containing the compounds of formulae (2) and (3) and the water/polar organic solvent. On the other hand, the compound of formula (4) is kept remaining in the organic layer.
Depending on the type of the solvent that dilutes the organic layer containing the compounds of formulae (2) to (4), the intended compounds could not be extracted into the water/polar organic solvent. In such a case, it is desirable to remove the solvent that has previously diluted the compounds, according to a known method of distillation or the like. Preferably, the polar organic solvent is an aliphatic alcohol having from 1 to 3 carbon atoms, or acetonitrile. In this case, the solution may be separated more readily from the organic layer through liquid-liquid separation, than in a case where the polar organic solvent has 4 or more carbon atoms. The diluent solvent is preferably any of aliphatic hydrocarbons or cycloaliphatic hydrocarbons having from 6 to 10 carbon atoms, or aromatic compounds such as benzene, toluene, xylene, ethylbenzene, cumene, mesitylene, pseudocumene or the like, as facilitating the liquid-liquid separation from the water/polar organic solvent.
The water/polar organic solvent for use herein may be prepared generally by mixing them in a ratio of from 2 to 10 times by weight of a polar organic solvent relative to the basis amount, 1, of water, preferably from 3 to 7 times by weight. In this case, the extraction efficiency for the compounds of formulae (2) and (3) increases more than in a case where the ratio of the polar organic solvent is less than 2 times by weight. In addition, as compared with a case where the ratio of the polar organic solvent is more than 10 times by weight, the present case is more favorable in that the extraction of the compound of formula (4) is well inhibited and that the failure in liquid-liquid separation of the reaction solution is also well inhibited. The amount of the water/polar organic solvent to be used may be from 0.2 to 10 times by weight relative to the basis amount, 1, of the solution containing the compounds of formulae (2) to (4), preferably from 0.5 to 4 times by weight, more preferably from 0.8 to 2 times by weight. When the amount of the water/polar organic solvent to be used is within the above range, then the extraction efficiency is enhanced more than in a case where the amount is less than 0.2 time by weight, and in addition, the compound of formula (4) is prevented more sufficiently from being extracted into the water/polar organic solvent than in a case where the amount of the water/polar organic solvent to be used is more than 10 times by weight. The extraction frequency is not specifically limited, as depending on the extraction efficiency; but in general, the extraction may be once to 6 times.
After processed for extraction with the water/polar organic solvent, the organic layer contains the compound of formula (4) at high purity. The organic layer is processed for separation through treatment with activated carbon, filtration, concentration, crystallization or the like, or through a combination of those treatments, whereby the compound of formula (4) may be readily separated and purified.
(Back-Extraction Step)
Next, from the water/polar organic solvent solution containing a mixture of the compounds of formulae (2) and (3) and a water/polar organic solvent, the compounds of formulae (2) and (3) are separated through solvent extraction. Specifically, a non-polar organic solvent is added to the water/polar organic solvent solution to thereby back-extract the compound of formula (3) into the non-polar organic solvent while the compound of formula (2) is kept remaining in the water/polar organic solvent solution. As the non-polar organic solvent, preferred are aliphatic hydrocarbons or cycloaliphatic hydrocarbons having from 6 to 10 carbon atoms, alkylbenzenes such as toluene, xylene, ethylbenzene, cumene, mesitylene, pseudocumene, or aromatic compounds such as benzene, as capable of attaining good liquid-liquid separation from the water/polar organic solvent.
In the present back-extraction step, the polarity of the water/polar organic solvent may be changed by adding water or by removing the polar organic solvent through evaporation. Applying this operation may better the separability of the compounds of formulae (2) and (3).
The amount of the non-polar organic solvent to be used may be generally from 0.2 to 10 times by weight relative to the basis amount, 1, of the water/polar organic solvent solution containing a mixture of the compounds of formulae (2) and (3), preferably from 0.5 to 4 times by weight, more preferably from 0.8 to 2 times by weight. In this case, the back-extraction efficiency is better than in a case where the amount of the non-polar organic solvent to be used for back extraction is less than 0.2 times by weight; and the reactor-base yield is higher than in a case where the amount of the non-polar organic solvent to be used for back extraction is more than 10 times by weight. The extraction frequency is not specifically limited, as depending on the extraction efficiency; but in general, the extraction may be once to 4 times.
The back-extracted non-polar organic solvent contains the compound of formula (3) at high purity. The organic layer is processed for separation through treatment with activated carbon, filtration, concentration, crystallization or the like, or through a combination of those treatments, whereby the compound of formula (3) may be readily separated and purified.
After the back extraction, the water/polar organic solvent contains the compound of formula (2) at high purity. The water/polar organic solvent layer is processed for separation through treatment with activated carbon, filtration, concentration, crystallization or the like, or through a combination of those treatments, whereby the compound of formula (2) may be readily separated and purified.
In the manner as above, adamantyl (meth)acrylates of formula (4) and adamantyl (meth)acrylates of formula (3) are obtained. According to the production method of the present invention, adamantyl (meth)acrylates of formulae (3) and (4) can be separated efficiently, not requiring column purification. Accordingly, the production method of the present invention is suitable for industrial-scale production.
Hereinafter the contents of the present invention will be described more concretely with reference to Examples and Comparative Examples. However, the present invention should not be restricted at all by the following Examples.
Example 1
126 g of 1,3-adamantane-diisopropanol and 1000 ml, of 1,2-dichloroethane were fed into a 5-neck flask equipped with a stirrer, a thermometer, a Dimroth condenser and two dropping funnels; and 105 g of methacryloyl chloride and 151 g of triethylamine were simultaneously dropwise added thereto, taking 1 hour. Next, the reaction solution in the 5-neck flask was stirred at 59 to 65° C. for 4 hours, then the reaction solution was cooled to room temperature, and thereafter 100 mL of water was added thereto to stop the reaction. Since the unreacted starting compound partly precipitated therein, the reaction solution was filtered under suction through a 5C paper filter and separated into the unreacted starting compound and a filtrate. In this stage, the amount of the unreacted starting compound was 25 g. The filtrate was separated into an organic layer and an aqueous layer. Next, the organic layer was washed with 800 g of aqueous 5% sodium hydroxide solution, 250 mL of ion-exchanged water, 750 g of aqueous 10% sulfuric acid solution, 250 mL of ion-exchanged water, and 250 mL of ion-exchanged water in that order, and then concentrated to give 138 g of a crude product. 320 mL of hexane was added to the thus-obtained crude product, and the unreacted starting compound precipitated. The crude product was filtered under suction through a 50 paper filter, thereby giving 15 g of the unreacted starting compound and a hexane solution.
64 mL of water and 320 mL of methanol were added to the obtained hexane solution, and well stirred, and the resulting liquid was separated into a hexane solution and a water/methanol solution through liquid-liquid separation. This operation was thereafter repeated further three times.
1374 g of the water/methanol solution was concentrated to 565 g. 640 mL of heptane was added to the thus-concentrated water/methanol solution, well stirred, and the resulting liquid was separated into a heptane solution and a water/methanol solution through liquid-liquid separation. Further, 640 mL of heptane was added to the concentrated water/methanol solution, well stirred, and the resulting liquid was separated into a heptane solution and a water/methanol solution through liquid-liquid separation. All the heptane solutions collected in the above liquid-liquid separation were mixed, then 12 g of activated carbon was added thereto and stirred for 1 hour, and thereafter this was filtered through a 5C paper filter and a membrane filter (pore size: 0.1 μm). The heptane layer thus recovered in the filtrate was concentrated and stirred at 0° C. for 1 hour, thereby giving 43 g of 2-methacryloyloxy-2-(3-(2-hydroxy-2-propyl)-1-adamantyl)propane (monomethacrylate of the starting compound).
On the other hand, the hexane solution after the extraction was concentrated, then methanol was added thereto, and this was cooled to 0° C. to give 4 g of 2-methacryloyloxy-2-(3-(2-methacryloyloxy-2-propyl)-1-adamantyl)propane (dimethacrylate of the starting compound).
Example 2
25 g of 1,3-adamantane-diisopropanol, 50 mL of tetrahydrofuran, 70.5 g of pyridine and 0.0986 g of phenothiazine were fed into a 4-neck flask equipped with a stirrer, a thermometer, a Dimroth condenser and a dropping funnel, and heated to 50° C. 10.3 g of methacryloyl chloride was dropwise added thereto, taking 15 minutes. Next, the reaction solution was stirred for 4 hours while kept at 50° C. Next, the reaction solution was cooled with ice, then 50 mL of ion-exchanged water was dropwise added thereto, and this was poured into 500 g of aqueous 10% sulfuric acid solution. Further, 100 mL of heptane, 30 g of sodium chloride and 250 mL of tetrahydrofuran were added to the aqueous 10% sulfuric acid solution, then well stirred, and thereafter the resulting liquid was processed for liquid-liquid separation into an organic layer and an aqueous layer. The organic layer was washed with 250 mL of ion-exchanged water, 100 g of aqueous 5% sodium hydroxide solution, and 250 ml, of ion-exchanged water in that order. 235 g of the organic layer was concentrated under reduced pressure to 68 g, then 100 mL of heptane was added thereto, and this was re-concentrated to 117 g. The organic layer was cooled with ice for 2 hours, and the organic layer with the starting compound precipitated therein was filtered under suction through a 5C paper filter, and separated into the precipitated starting compound and a filtrate.
The precipitated starting compound was rinsed with 100 mL of heptane. The recovery yield of the collected starting compound was 35%. On the other hand, the filtrate was analyzed through HPLC, which confirmed the existence of the starting compound, the monoester and the diester in the filtrate, in an yield ratio by mol of starting compound/monoester/diester=2/38/4 (based on the starting compound fed in the reactor). The filtrate was extracted four times with methanol (50 mL)/ion-exchanged water (10 mL). Through this operation, the starting compound and the monoester were separated from the diester. The methanol/ion-exchanged water solution was concentrated to 211 g, and extracted twice with 150 mL of heptane. Through this operation, the starting compound and the monoester were separated from each other. The heptane layer obtained in this stage was analyzed through HPLC, which confirmed the existence of the starting compound, the monoester and the diester in the heptane layer, in a mole yield of starting compound/monoester/diester 0.4/27/0.3 (based on the starting compound fed in the reactor). The heptane layer was concentrated under reduced pressure to 23 g, and a seed crystal of the monoester of the starting compound was added to the heptane layer, which gave a crystal therein. The heptane layer was further cooled with ice for 2 hours, and then filtered under suction through a 5C paper filter thereby giving 7.4 g of 2-methacryloyloxy-2-(3-(2-hydroxy-2-propyl)-1-adamantyl)propane (monomethacrylate of the starting compound).
On the other hand, the filtrate after the extraction with methanol/ion-exchanged water was concentrated, then methanol was added thereto, and this was cooled to 0° C. to give 2-methacryloyloxy-2-(3-(2-methacryloyloxy-2-propyl)-1-adamantyl)propane (dimethacrylate of the starting compound).
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The present invention provides an efficient production method suitable to industrial-scale production not requiring column purification for adamantyl (meth)acrylates having an adamantine skeleton having utility in crosslinked resins, optical fibers, optical waveguides, optical disc substrates and other optical materials.
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BACKGROUND OF THE INVENTION
Fetal monitoring during labor and birth has become standard procedure in obstetric centers in the United States. Typically during early stages of labor extrauterine ultrasound probes placed on the maternal abdomen derive a signal which when processed yields fetal heart rate and maternal contractions. Subsequently, when labor has advanced to the point that the amniotic membranes have ruptured, the maternal cervix has dilated to 3 cm. and the fetus' head is presented, electrodes that penetrate the scalp are fastened to the fetus' displayed head. The signals picked up by this electrode are directed through multi-component processors yielding fetal heart rate (hereinafter FHR). Comparators in multi-component processors compare current FHR vs. FHR over time as well as a preprogrammed normal current FHR and FHR over time. Some systems have alarms incorporated into the circuits which are preset to alert the obstetric team (hereinafter OBT) that FHR is too high/too low, etc. The thus measured FHR is one of the means of detecting fetal distress. Based on FHR plus ultrasound viewing of the fetus and maternal medical indications the OBT may take other action such as inserting probes through cervical os to measure amniotic fluid pressure and maternal contraction pressure. In some cases, such as prolonged labor or early rupture of the membranes, synthetic amniotic fluid may be infused into the uterus to relieve fetal distress. In other instances the OBT may reach the conclusion that labor should be terminated by cesarian delivery.
In many cesarian deliveries triggered by FHR information it has been found that the fetus was not really in critical distress and could have been vaginally delivered in normal fashion.
One of the shortcomings of the state of the art systems is the variability of FHR which may change quite dramatically during maternal contractions. This information gathered by the sensors attached to the fetus' scalp is processed by multi-processors and is included in the readout of average FHR vs. actual and time line FHR. This processed information may lead the OBT to conclude there is fetal distress. However, this may not be the case, merely FHR slowing because of extracranial pressure caused by the maternal contractions.
Alternatively such processed FHR readings may not show actual fetal distress.
OBJECT OF THE INVENTION
The primary object of the invention is to supply the OBT with specific medical information about an inutero fetus during maternal labor to properly assess fetal well being.
An important object of the invention is to provide sensors which permit the monitoring of FHR, blood chemistry blood oxygen saturation and to eliminate the processing of FHR and blood chemistry information during maternal contraction cycles.
It is another important object of the invention to supply the OBT information regarding arterial blood flow to the scalp and by extrapolation to the brain.
PRIOR ART
The following art was found in a preliminary search for patentability.
U.S. Pat. No. 5,088,497--February, 1992--Ikeda--processing apparatus correlated between maternal pain intensity and fetal heart rate. Division of U.S. Pat. No. 5,069,218.
U.S. Pat. No. 5,046,965--September, 1991--Neese et al.--connector for coupling fetal scalp electrodes and maternal body for base references.
U.S. Pat. No. 5,042,499--August, 1991--Frank et al.--apparatus to non-invasively obtain from the maternal abdomen fetal ECG signal.
U.S. Pat. No. 5,025,787--June, 1991--Sutherland et al.--intrauterine probe which monitors Fetal Heart Rate and pressure sensor to develop intrauterine pressure.
U.S. Pat. No. 5,012,811--May, 1991--Malis--apparatus to affix fetal electrode to fetal scalp with OBT protective shield.
U.S. Pat. No. 4,951,680--August, 1991--Kirk et al.--apparatus to filter and process FHR signals from an electrode affixed to a fetus to establish changes or variation in the FR electrocardial interval which is useful to indicate fetal acidosis.
U.S. Pat. No. 4,945,917--August, 1990--Akselrod et al.--apparatus and method for displaying Fetal R-wave while eliminating maternal R-wave signal.
U.S. Pat. No. 4,934,371--June, 1990--Malis et al.--Spiral scalp electrode fetal monitoring device with protective shield to protect OBT.
U.S. Pat. No. 4,898,179--February, 1990--Sirota--Device for monitoring of fetal and maternal vital signs also permitting communication between mother and her fetus.
U.S. Pat. No. 4,890,624--January 1990--Ganguly et al.--Ultrasound doppler signal processor to determine FHR.
U.S. Pat. No. 4,873,986--October, 1989--Wallace--disposable uterus invasive apparatus for monitoring intrauterine pressure and FHR.
U.S. Pat. No. 4,781,200--November, 1988--Baker--Continuous ambulatory non-invasive fetal well being monitor apparatus.
U.S. Pat. No. 4,722,730--February, 1988--Levy et al.--uterine invasive apparatus for simultaneously monitoring intrauterine pressure and delivering infusible fluids for relief of fetal distress.
U.S. Pat. No. 4,644,956--February, 1987--Morgtenstern--fetal scalp electrode adapted to be transcervically fixed to the fetus.
None of the above combine the features of the instant invention nor method of affixing sensors to the fetus.
Other prior art which may be of interest follows.
U.S. Pat. No. 4,830,014--May, 1989--Goodman et al.--conformal sensor for transillumination of blood perfused portion of flesh to measure light extinction.
U.S. Pat. No. 4,700,708--October, 1987--New et al.--probe for use with an optimal oximeter.
U.S. Pat. No. 4,621,643--November, 1981--New et al.--solid state monitor for determination of oxygen saturation and pulse rate.
U.S. Pat. No. 4,167,331--September, 1979--Nielson --Multi-wavelength increment absorbance oximeter.
U.S. Pat. No. 3,998,550--December, 1976--Konishi et al.--photoelectric oximeter.
U.S. Pat. No. 3,847,483--November, 1972--Shaw et al.--optical oximeter apparatus and method.
U.S. Pat. No. 3,704,706--December, 1972--Herezfeld et al.--photo electric apparatus for detection of pulse rate and oxygen content of blood.
U.S. Pat. No. 3,638,640--February, 1972--Shaw--oximeter method and apparatus to determine oxygen saturation of blood.
U.S. Pat. No. 2,706,927--April, 1955--Wood--apparatus for determining percentage of oxygen saturation of blood.
SUMMARY OF THE INVENTION
In its simplest form the instant invention utilizes ongoing spectrophotomeric analysis of fetal blood in combination with or without pressure switches and pressure measuring devices which are combined in a single unit which is easily applied inutero to fetal flesh. Many other devices have been devised to measure individual parameters such as intrauterine pressure and fetal heart rate. None of the devices found in commerce or prior art reveal a device which monitors in utero fetal blood oxygen content, blood chemistry, maternal contraction pressure as well as eliminating information gathered during maternal contractions. The elimination of this information is important since the changes in FHR measured during maternal contractions may reflect normal physiological response but if averaged into ongoing FHR monitoring may distort the overall FHR information. The most common spectrophotometric analyzers in use are oximeters of the prior art. They function by transillumination of flesh with tuned wavelength light and a receiver or sensor tuned to be responsive to the absorption of wavelengths transmitted by the light source. The usual wavelength range of light source in these devices is in the near red range and specifically 540-580 nanometers range which is the range wherein absorption of light by single bound oxygen such as in hemoglobin is strongest. From such absorption data it is possible to determine total blood hemoglobin content and oxygen solution by determining the ratio of oxyhemoglobin to deoxyhemoglobin.
This information alone is a most useful monitoring tool to determine stress in an exutero patient because basic gravimetric or spectrogravimetric analysis of blood and urine have usually been or can be done to establish basic organ, cellular and metabolic function. This valuable base line information is not available nor readily obtainable in an inutero fetus.
It is one of the features of the invention to permit the instant ongoing non fetal invasive determination and ongoing monitoring of base line blood information. This is accomplished by use of transillumination of fetal flesh with an infrared light source and tuned receiver or sensor which is responsive to predetermined infrared absorption wavelengths. Most commonly indications of muscle damage, organ and cellular malfunction is by generation of chemicals in unusual amounts which become a constituent of blood. For example, measurable amounts of myoglobin indicates muscle damage. Similarly, significant amounts of aliphatic esters and ketones such as acetoacetone, acetone and b-hydroxybutyrate are indicative of cellular and organ malfunction.
Most of these chemicals exist as organic anions. The first indication of distress is an increase in total blood serum organic anion content (exclusive of protenate). Blood anion includes a great variety of individual ions of which lactate is usually most abundant to make up about 80% of the total organic anion fraction. The remaining 20% is made up of fatty acids, amino acids and others produced during normal metabolism. In various disease states some of these minor anions accumulate to significant concentrates. For example increase in total anion concentrates above 26 mmol/ion charges/l usually indicates renal problems. Similarly when lactate concentrations reach 25 mmol/l indicates lactic acidosis. Increase of keto acids, ketones and secondary alcohol acid ions may indicate metabolic problems and liver malfunction.
The organic aliphatic acids, amino acids, esters, ketone and alcohols have very narrow absorbancy characteristics in the infrared range wavelengths from 700-1,000 nanometer range. For example ionized aliphatic acid(anionic) absorb in the 700 nanometer range, aliphatic esters absorb in the 810 nanometer range and aliphatic ketones in the 840 nanometer range. Similarly double bound oxygen as found in myoglobin responds in the 825 nanometer range. Therefore the incorporation of CWLS and and tuned sensors that respectively radiate and sense absorption in the 540-590 and 700-825 nanometer range into a single device along with pressure switch and pressure measuring devices develops all of the data necessary for the OBT to assess ongoing fetal well being.
Perhaps the most significant early alerting of fetal distress is the detection of unusual amounts of organic anions (700 nanometers) which by extrapolation (i.e. every ionized anion must have a cation which is usually a Hydrogen ion) is an indication of possible low pH of fetal blood. Subsequent determination of the other components of the blood organic ion at other infrared wavelengths will provide the OBT with information as to the specific reason for the elevated organic ion level in the blood. This device can easily be adhered to a fetus' head or body via cervical insertion. The device is affixed to the fetus' head or body using well known transparent water based gel adhesives or alternatively affixed to the presented fetal scalp by the well known corkscrew FHR devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the probe of the instant invention with CWLS tuned receiver, pressure switch and transducer.
FIG. 2 is a plan view of an intrauterine lariat probe.
FIG. 3 is a side view of an intrauterine lariat probe affixed to fetus' extremity.
FIG. 4 is a side view of FIG. 1 illustrating layer of gel adhesive layer to affix to fetus.
FIG. 5 is a sagittal view demonstrating placement of device on fetus' head.
FIG. 6 is a sagittal view demonstrating proper initial insertion of lariat device.
FIG. 7 is a sagittal view of proper ensnarement of fetal extremity.
FIG. 8 is a side view of CWLS and tuned sensor, mounted on known corkscrew scalp electrode.
DETAILED DESCRIPTION
FIG. 1 is a plan view of the sensor pad 10 of this invention which is designed to be intercervically adhered to the fetus' face or chest. It includes a controlled multi-wavelength light source (CWLS) such as a light emitting diode. A light sensor 4 which is responsive to the transilluminated wavelengths emitted by source 2, a pressure sensitive switch 6 and a pressure measuring device such as a transducer 7. Each of these devices have signal transmission cables (not shown) which are connected into microprocessors which are programmed to interpret absorption response to yield medical data such as pulse rate, blood chemistry and blood oxygen levels and intrauterally developed pressure. The placement of CWLS and receiver in proper relationship to each other is significant in supplying and sensing the reflected CWLS after passing through the cutaneous vascular area of the fetus. Experimentally it has been found that the angular relationship between the CWLS and sensors should at maximum be an arc A of 90° locations 2-4 and at minimum but no less than an arc B of 45° locations 2A-4A. Deviation from this range significantly changes the ability of the sensor to pick up proper absorption of radiated light to be transmitted to the interpreting microprocessor. The function of pressure switch 6 is to shut down transmission of sensor 4-4A when maternal contractions occur as when device 10 is applied intercervically to fetus' scalp, face, neck or body area FIG. 5 and adhered with an optically transparent gelatin adhesive 42 FIG. 4. In this location CWLS 2(2A) illuminates fetus' head cutaneous area and sensor 4(4A) generates signal which is transmitted to the microprocessor. Since pressure switch 6 stops transmission of that signal when contractions force fetal head into cervical area there is no need for circuitry or programming to interpret the signal as it changes in pulse rate, blood flow rate, blood oxygen level or blood chemistry. Thus only unstressed fetal non-maternal contracting pulse rate, blood flow rate, blood oxygen and chemistry are microprocessed eliminating the gathering of information which may cause the OBT to falsely determine that the fetus is distressed. Transducer 7 continues to function thus supplying OBT with maternal contracting pressure to assist in determining the progression of labor. The transducer 7 should have a sensitivity of range from 10 PSI (0.70 kg/sq.cm.) through 80 PSI (5.63 kg/sq.cm.) to function reasonably as a maternal contraction pressure indicator. This range of maternal contracting pressure is well known having previously been developed by intrauterine devices of the prior art.
The laminate sensor pad of the instant device 40 FIG. 4 is made up of three layers, the first of which is a transparent adhesive layer 42 the second a transparent film 46 which covers the CWLS, responsive sensor, pressure responsive switch and transducers and a bottom conforming layer 44. The CWLS responsive sensor, pressure responsive switch, transducer and interconnect wires 48 in cable 50 being sandwiched between the bottom layer and transparent film.
The gel adhesives utilized in bonding the pad to fetus are known and are largely commercially available. Such gels are colloids in which the disperse phase has been combined with the continuous phase. They are usually transparent. Flow, adhesive qualities and compatability with various body fluids are determined by formulation and rate of cooling a solution wherein the solutes form submicroscopic crystalline particle groups which retain solvents and other formulating chemicals in the interstices of the crystalline particles (so called brush heap structure). Specific formulations of these adhesives do not irritate even tender neonatal skin and are easily washed off the delivered infant.
FIG. 2, a second variation of the instant invention, is designed for intrauterine application wherein the components of sensor pad 10 are incorporated onto a lineal semi-flexible member 20 which may be plastic with controlled flexural modulus. End member 24 friction fits into slit 22 forming a lariat. The lariat FIG. 3 which is affixed to semi-flexible tube member 30 which also must have a controlled flexural modulus. The assembly of 20 and 30 when formed into a lariat is passed through the cervix by the OB after the membranes have ruptured FIG. 6. Thence by manipulation device 20 by tube 30, which is usually followed by ultrasound imaging, the OB snares fetus' extremity 50. Device 20 is then tightened to bring CWLS 2, tuned sensor 4, pressure switch 6 and transducer 7 in contact with fetus' extremity 50. Rapid release of formed lariat requires only a tug by the OB to have end 24 clear from friction fit slit 22. The device and connecting tube are then easily removed from the uterus via the dilated cervix.
In another variation, the device 10 is affixed to the commonly used scalp electrode. In this instance the backing material 44 for pad 62 shown in FIG. 8 is made of a somewhat springing plastic which has been formed into a slight concave arc so that as scalp electrode is screwed into fetus' scalp 64 it contacts fetus' scalp with slight spring conforming to the radius of the fetus' head to ensure scalp contact of CWLS 2 and sensor 4. In this form the device does not include a pressure switch or pressure measuring means, only CWLS and controlled wavelength light sensor. The device as shown has a separate backing but it should be understood that the CWLS and light sensor could be incorporated directly into the base of a modified scalp electrode as long as the geometry of separation of CWLS and sensor is maintained. This compound device will permit the ongoing FHR as well as the other essential fetal medical information. In order to block out response during maternal contractions it is coupled with a separate device 70 FIG. 8 with pressure switch 6 and transducer 7 which monitors maternal contraction and pressure and blocks transmission of FHR and CWLS reflection during maternal contraction as aforesaid transmission of information from the sensor to the microprocessor is interrupted during maternal contractions thus eliminating information which may reflect on fetal distress during maternal contractions. A transparent gel may be used under the CWLS and sensor to eliminate extraneous information which may develop because of contamination of the fetal scalp. The composite device 62 can readily be removed in normal fashion just prior to fetus' head passing through the cervix.
The instant invention may incorporate a single CWLS and receiver to be responsive to absorption of such emitted radiation.
Alternatively, multiple individually tuned CWLS and multiple individually tuned sensors may be used particularly if they are tuned to respond to the desired wavelengths for optimum absorption for given blood components.
It is thought that the above described device will be most useful for inuterine fetus monitoring to be able to more clearly define fetal stress during delivery to better be able to determine if and when c-section delivery is required.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. As such, the scope of the invention is therefore indicated in the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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An improved fetal monitoring device which incorporates sensors which permit the monitoring of inutero fetal heart rate, oxygen saturation, blood chemistry and eliminates the collection of such information during maternal contractions.
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BACKGROUND
1. Field of the Invention
The present invention relates to a fabric valve, and more particularly, to a fabric valve for use in air bags or similar vehicular safety devices.
2. Background of the Invention
Modern passenger vehicles are manufactured with a number of safety features that are designed to minimize passenger injury in accidents. Such features include, for example, rollover bars, uni-body construction, seat belts, and inflatable devices, such as, for example, air bags and air curtains. Inflatable devices generally remain in an inactive compressed condition until an impact or other physical stimulus activates such devices to inflate to protect passengers during an accident.
Thus the term “inflatable devices” will be used throughout this disclosure to describe devices that typically are in an inactive compressed state until a trigger activates them to become inflated. Such devices include, but are not limited to, air bags, air curtains, inflatable tubular structures, and air walls. Inflatable devices generally have an inflatable structure in fluid communication with a source of compressed gas or a gas generator, which, upon activation, releases gas into the inflatable structure.
Some conventional air bag systems have multiple bags and gas inflatable compartments, thereby allowing for different and typically layered cushion zones to handle soft and hard passenger impacts. Valves may be used between these different cushion zones to control the amount of gas passable between the zones. These valves may be one-way valves that are simple in design, but may not be fully successful in preventing back flow of gas from a high pressure gas cushion zone to a lower pressure gas cushion zone. Thus, there is a need for a device that acts as a one-way valve to restrict the flow of gas to one direction.
SUMMARY OF THE INVENTION
The present invention is a fabric valve that is made of a fabric blank folded in a pattern that promotes the flow of fluid in one direction along an axis of the fabric valve, but restricts the flow in the opposite direction along the same axis. The valve is manufactured from, for example, a rectangular sheet of fabric. A series of simple folds are used to create a fabric valve that is then attached onto an inlet tube such that gas is only directed in one direction. The fabric valve prevents backflow of gas back through the valve by creating a wall of fabric that seals the valve when a higher pressure is sensed downstream of a moving lip mechanism on the valve.
An exemplary fabric valve implementing the present invention includes a fabric blank having a top edge, a left edge, a bottom edge, and a right edge. A Z-fold is created along the right edge thereby resulting in a Z-folded fabric blank. The Z-folded fabric blank is folded in half along a first traverse fold line that is parallel to the top and bottom edges to result in a bi-folded fabric blank. The bi-folded fabric blank is further folded in half along a second traverse fold line that is parallel to the top and bottom edges and the first traverse fold line to result in a quad-folded fabric blank. The fabric valve further has a first line of stitches parallel to the second traverse fold line. The first line of stitches secures a portion of the Z-fold at the second traverse fold line. The fabric valve also has a second line of stitches parallel to the first line of stitches. The second line of stitches secures another portion of the Z-fold at the first traverse fold line, the top edge, and the bottom edge. Fluid is restricted to flow through the quad-folded fabric blank only in a direction from the left edge to the right edge (and not vice-versa).
Another exemplary implementation of the present invention is an easy to follow method for making a fabric valve. First, a fabric blank having a top edge, a right edge, a bottom edge, and a left edge is selected. A Z-fold is created along the right edge to result in a Z-folded blank. The Z-folded blank is folded in half along a first traverse line perpendicular to the Z-fold to result in a half-size Z-folded blank. The half-size Z-folded blank is folded in half along a second traverse line perpendicular to the Z-fold to result in a quarter-size Z-folded blank. The quarter-size Z folded blank is secured along the second traverse line from the right edge across a width of the Z-fold. The quarter-size Z folded blank is secured along the first traverse line from the right edge to the left edge.
Yet another exemplary implementation of the present invention is an inflatable vehicular safety system that contains a fabric valve that promotes gas flow in one direction but restricts gas flow in the opposite direction. The system includes a first chamber that is adapted to receive gas from a gas generator. The system also includes a fabric valve having a body member and a Z-fold member. The body member includes four layers of a fabric blank and is adapted to receive a portion of the gas from the first chamber and to discharge the portion of gas out of the Z-fold member. The Z-fold member includes 12 layers of the fabric blank. The system also includes a second chamber upon which the fabric valve is attached, wherein the second chamber receives the portion of gas from the first chamber through the fabric valve. When the first chamber experiences a decrease in pressure, the Z-fold member prevents the portion of gas in the second chamber from returning to the first chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an isometric view of an exemplary embodiment of the present invention.
FIGS. 2A through 2E are explanatory views for explaining how the fabric valve shown in FIG. 1 may be made.
FIGS. 2 AA through 2 DD are side cut views of the fabric valve in FIGS. 2A through 2D, respectively.
FIG. 3 is a schematic diagram showing how the fabric valve shown in FIG. 1 may be attached in an inflatable tubular structure.
FIG. 4 is an expanded view of area 400 indicated in FIG. 3 .
FIG. 5 is a schematic diagram of the fabric valve between two gas chambers in an inflatable vehicular safety system.
FIG. 6 is another exemplary embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An exemplary embodiment of the present invention is a fabric valve for use in conjunction with an air bag or similar vehicular safety device. A typical vehicular safety device for use with the present invention is the Inflatable Tubular Structure (“ITS”) manufactured by Simula, Inc. of Phoenix, Ariz. ITS is fully disclosed in U.S. Pat. Nos. 5,322,322 and 5,480,181 (both issued to Bark et al.), each of which is hereby incorporated herein by reference in its entirety.
The present invention may be adapted for use with other vehicular safety devices having two or more air chambers. For example, it may be used in any multi-chambered inflatable device wherein gas passes through the chambers and exists at different pressures in different chambers. A fabric valve according to the present invention would be suitable to restrict backflow between the chambers.
An exemplary embodiment of the present invention is a fabric valve that is designed for use in an air bag system in which a single gas generator fills an ITS through an inlet fill tube and also fills a separate curtain-style (i.e., curtain type) air bag. Gas fills the ITS by entering a bladder of the ITS through the fill tube and fabric valve, but is restricted by the fabric valve from flowing back out of the bladder. Typically, an air bag only remains inflated for less than one second, whereas an ITS preferably remains inflated for a longer period. In this system, the curtain-style air bag may leak at a higher rate than the ITS, causing gas to flow out of the ITS and back into the curtain bag. Therefore, a valve that prevents backflow, such as the fabric valve described herein, may be required to increase the inflated time of the ITS in this air bag system.
FIG. 1 is a schematic diagram showing an isometric view of an exemplary embodiment of the present invention. Fabric valve 100 is folded in a unique configuration that is most advantageous to an airbag for which the fabric valve is designed. Fabric valve 100 includes one or more substantially planar sheets 110 of a fabric. Fabric valve 100 may comprise multiple layers 121 , which may be multiple separate sheets 110 attached together or a single sheet 110 folded into multiple layers. The exemplary embodiment shown in FIG. 1 is a single sheet folded into multiple layers, but multiple separate sheets attached together by suitable adhering means, such as, for example, thread, adhesive, clips, or the like, also may be used. In the exemplary embodiment shown in FIG. 1, the single sheet 110 is folded to form at least two free ends 120 and a folded end 122 . The fabric valve 100 has an inlet end 125 and an outlet end 126 , a top side 140 and a bottom side 145 . At the outlet end 126 , there may be a multiple fold region having multiple folds 130 . The multiple layers of the fabric valve 100 may be adhered together through adhering means, such as, for example, thread, adhesive, clips, or the like. In the exemplary embodiment shown, a top stitch 150 secures the top side of the fabric valve 100 and bottom stitch 160 secures the bottom side of the fabric valve. Other stitches also may be used. The stitches provide structural stability to the fabric valve by preventing disintegration of the valve at high pressures, and also serve to keep the valve closed when higher pressures are present downstream of the valve, described in more detail below.
The fabric valve 100 is a piece of fabric folded and attached to the end of the ITS fill tube. The fold pattern and stitching on the fabric valve 100 are dependent upon one or more factors. The factors are, for example, the nature of the fabric used, desired strength of valve, and anticipated fluid pressures and temperatures that would be encountered during deployment. For example, higher density stitching would be more desirable for higher strength fabrics. Such a fabric may be constructed of, but is not limited to, the same types of fabrics used in construction of an air bag or air curtain. Thus, a silicone-coated nylon fabric could be used. Heavier fabrics that may be used include a double side silicone-coated nylon. For the heavier fabrics, the stitching is usually denser to preserve the integrity of the fabric valve. The valve material and configuration are dependent upon the gas generator used in the air bag system. The temperature and pressure of the gas determines the fabric weight, coating weight, thread material, and sewing configuration. Multiple fabrics, thread materials, and stitch densities may be used to construct a valve according to each application.
Materials that may be needed to construct an exemplary embodiment of the fabric valve 100 include, but are not limited to, fabric, fabric coating, and thread. The fabric may be, for example, nylon, from about 420 denier to about 840 denier. The fabric coating may be applied on a single side or on both sides of the fabric. Such fabric coatings may be, for example, silicone, neoprene, or other such coatings. The thread used to stitch the fabric may be, for example, nylon, polyester, para-aramid (KEVLAR), or other such threads.
The seams in the fabric valve 100 may have varying stitch densities. For example, stitch densities of about six stitches per inch to about 20 stitches per inch may be used. One or more needles may be used to sew the seams. For example, a double needle may be used to create two parallel seams. A silicone sealant may be used to seal the threads at the stitch points. Alternatively, an adhesive may be used to promote the seal of the stitches or to adhere the layers of fabric together.
The fold geometry may vary from the exemplary embodiment shown in FIG. 1 without departing from the scope and spirit of the present invention. For example, alternative fold geometries may have: different lengths of segments; differing numbers of layers; different location and numbers of transverse folds; different number of folds in series; different lengths of materials on different sides of the folds; and different widths of the folds; or the like, without departing from the scope and spirit of the present invention.
The variables described above are tuning parameters, which can be utilized to modify the valve design based upon a desired need. For example, a higher temperature and pressure gas may require a higher denier fabric with heavier coating and a double needle seam with sealant. Based on the operating pressure, the fold geometry (length, number of folds, etc.) may be changed.
FIGS. 2A through 2D, and 2 AA through 2 DD, are explanatory views for showing how a fabric valve 200 shown in FIG. 2E may be made. Fabric valve 200 comprises a fabric blank 210 , which may be of a suitable size and material to communicate with a corresponding ITS (not shown). Preferably, the fabric blank 210 has a rectangular shape with a top edge 202 , a bottom edge 204 , a left edge 208 , and a right edge 206 . For example, each of the left 208 and right 206 edges is about 260 mm long, and each of the top 202 and bottom 204 edges is about 140 mm wide. Depending on the number of folds, length of folds, and seam geometry, these dimensions may range from about 60 mm to about 600 mm in width, and from about 200 mm to about 500 mm in length.
A Z-fold 218 is created along the right edge 206 (see FIGS. 2 B and 2 BB). For example, the Z-fold 218 is located approximately 15 mm from the right edge 206 . This results in a Z-folded fabric blank 230 having a width of about 90 mm, which is about 50 mm narrower than the unfolded fabric blank 210 . The “missing” 50 mm is overlapping within the Z-fold 218 . In other words, a first Z-fold line 212 is located about 75 mm from the left edge 208 to facilitate the fabric blank 210 to be folded downwards along the first Z-fold line 212 . A second Z-fold line 214 is located about 25 mm to the left of the first Z-fold line 212 to facilitate the fabric blank 210 to be folded downward along the second Z-fold line 214 . The remaining 15 mm of the fabric blank closest to the right edge 206 is exposed to the right of the first Z-fold line 212 . As shown in FIGS. 2 B and 2 BB, first Z-fold line 212 is above line 216 .
The Z-fold 218 may range in width from about 15 mm to about 75 mm, although the exemplary embodiment is shown having a width of 25 mm. The exposed material to the right of the Z-fold 218 in the figures may range from about 10 mm to about 50 mm in width.
Next, the Z-folded fabric blank 230 is folded in half along a first traverse fold line 220 (shown in FIGS. 2 B and 2 BB), that is parallel to the top 202 and bottom 204 edges. The first traverse fold line 220 bisects the Z-folded fabric blank 230 to create an upper half portion 232 and a lower half portion 234 . The upper half portion 232 is folded so that it is located below the bottom half portion 234 , resulting in a bi-folded fabric blank 250 shown in FIGS. 2 C and 2 CC.
The bi-folded fabric blank 250 is further folded in half to create a quad-folded blank 270 along a second traverse fold line 222 , as shown in FIGS. 2 C and 2 CC, that is parallel to the top 202 and bottom 204 edges and the first traverse fold line 220 . The second traverse fold line 222 bisects the bi-folded fabric blank 250 to create an upper quarter portion 252 and a lower quarter portion 254 . The upper quarter portion 252 is folded so that it is located below the bottom quarter portion 254 , resulting in a quad-folded fabric blank 270 shown in FIGS. 2 D and 2 DD.
Finally, the quad-folded fabric blank 270 may be sewn into place using one or more stitch lines, such as, for example, a first stitch line 242 and a second stitch line 244 to create and secure the fabric valve 200 . The stitch lines 242 and 244 may be of any suitable stitch design, such as, for example, a lock stitch. A single needle, such as, for example, a 140/22 needle, may be used to create the lock stitch. The start and end of the lock stitch may be about two mm from the top and bottom edges of the quad-folded fabric blank 270 . The stitch density may be, for example, about 10 to 12 threads per 25 mm, and may use, for example, IAW FED STD 751A TYPE 301. The stitch lines 242 and 244 may be of suitable geometry to handle internal pressure of the valve. For example, FIG. 6 shows a different stitch line configuration.
The fabric valve 200 may be attached in position with respect to an ITS 310 , as shown in FIG. 3 . For example, fabric valve 200 may be attached to the ITS 310 by sewing. The ITS 310 may have a bladder having a stretchable portion 330 that expands as gas enters the ITS 310 through an inlet tube 320 and the fabric valve 200 in direction 350 . Once the gas has entered into the ITS 310 as shown by arrow 350 , the gas is prevented from exiting back out of the inlet tube 320 by the fabric valve 200 which prevents gas backflow.
The stitch lines 242 and 244 are attached, for example by sewing, onto the ITS 310 . The inlet tube 320 is inserted within the body member 420 in a hole created by the fabric valve 200 . The inlet tube 320 is inserted into the fabric valve 200 to a depth that would not interfere with the Z-fold member 410 . Specifically, the Z-fold member 410 's moving lip mechanism (see FIG. 4) is not interfered with by the inlet tube 320 .
Referring to FIG. 4, the first stitch line 242 may be from about two mm to about 15 mm, for example, approximately five mm, from the fold line 222 . The length of the first stitch line 242 depends upon the length of the Z-fold 218 , and should extend past line 214 . For example, the first stitch line 242 could be about 50 mm long and slope upward and end at fold line 222 . The first stitch line 242 could range in length from about 25 mm to about 125 mm.
The position of the second stitch line 244 depends upon seam geometry, but should be from about ten mm to about 20 mm, for example, about 12 mm, from the bottom edge 204 within the Z-fold member 410 . The length of the second stitch line 244 depends upon seam geometry and the length of the member 410 and/or 420 . The second stitch line 244 may, for example, extend approximately 75 mm along the bottom edge 204 from the right edge 206 , before sloping upward and crossing lines 326 and 324 and communicating with inlet tube 320 . Within the body member 420 , the location of the second stitch line 244 depends upon valve and seam geometry. For example, the second stitch line 244 may be about 24 mm from the bottom edge, although it could range between about ten mm and about 75 mm.
Although the description of FIGS. 2-4 were made with specific dimensions, such dimensions are only exemplary, and are not intended to be limiting. Thus, one having ordinary skill in the art would change the dimensions accordingly to fit a particular geometry of ITS or inlet tube.
The fabric valve 200 may be attached onto the inlet tube 320 in one of several ways. For example, as shown in FIG. 4, fabric valve 200 may be secured with the inlet tube 320 through various stitches 324 and 326 that prevent relative movement of the fabric valve 200 with respect to the inlet tube 320 . As shown in FIG. 4, the front edge 322 of the inlet tube 320 stops short of the Z-fold line 214 , thereby eliminating any interference between the inlet tube 320 and the moving lip mechanism of the fabric valve 200 . Clamps, rivets, and other fasteners may be used to secure the fabric valve 200 onto the inlet tube 320 .
An exemplary method for making the exemplary embodiment of the present invention described above comprises the following steps. The valve begins as a flat blank of material of appropriate size for the application. A single Z-fold is made and temporarily clipped at one end of the fabric blank. The blank is then folded in half perpendicular to the original Z-fold, and then folded in half again to result in a blank one-quarter the size of the original Z-folded blank. Finally, the valve is sewn closed in a configuration according to its particular application.
The valve works by creating a resistance to the backflow of the gas. This resistance is created by a moving lip seal mechanism, which allows unidirectional flow by pinching closed when pressure is applied on the downstream side of the valve. The folding and sewing of the valve material results in a more rigid section in the valve (a lip) which opens with pressure from the upstream side, but closes when downstream pressure exceeds the upstream pressure.
As shown in FIG. 5, an inflatable vehicular safety system 500 includes a source of gas 510 , which typically is compressed gas or a gas generator. Upon sensing an impact, a signal triggers the release of gas from the gas source 510 through a gas conduit 520 to a chamber 530 , which may be an inflatable safety device, such as, for example, a curtain style air bag or the like. Another chamber 560 may be in communication with chamber 530 . The second chamber 560 may be, for example, an ITS or another inflatable structure. Gas may enter the second chamber 560 through a fill tube 540 . Attached to the fill tube 540 may be a fabric valve 550 , as described above. During operation, compressed gas may be released from the gas source 510 , thereby flowing to and inflating both chambers 530 and 560 . Gas in chamber 530 may leak out in the direction of arrow 571 to the ambient environment through gas escape point 570 . Thus, gas in chamber 530 remains at a higher than ambient pressure for a relatively short amount of time. For example, a conventional air bag remains inflated for about a second before deflating. However, gas that enters chamber 560 through fill tube 540 is prevented from escaping by fabric valve 550 , as described above.
Although the above system and fabric valve have been described with respect to a vehicular safety system, the present invention is not limited to only vehicles, and may be used wherever such an inflatable system may be used. Furthermore, such a fabric valve and system may be used to prevent the back flow of gas in an undesired path.
Furthermore, the above valve geometry shown in FIGS. 1-4 is only exemplary and is not intended to be limiting of the present disclosure. For example, the valve shown in FIG. 6 is another exemplary embodiment of the valve and is shown with a slope 610 on one side of the valve body. Other geometries for the valve that substantially perform the same functions of the valve described above also are within the scope of this invention.
In describing representative embodiments of the invention, the specification may have presented the method and/or process of the invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the invention.
The foregoing disclosure of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
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A fabric valve is disclosed that is made of a fabric blank folded in a pattern that promotes the flow of fluid in one direction along an axis of the fabric valve but restricts the flow in the opposite direction along the same axis. The fabric valve is easy to construct and is made by a series of folds. The fabric valve may be particularly suitable for use with inflatable safety devices used in vehicles, such as air bags and air curtains, to restrict backflow of gas from a given air bag when pressure, is applied to the bag. A method of making the fabric valve and a system incorporating the fabric valve are also disclosed.
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FIELD OF THE INVENTION
[0001] The present invention relates to electric machines, and more particularly to electric generators that are thermally protected from damage resulting from high currents in such machines.
BACKGROUND OF THE INVENTION
[0002] Permanent magnet electric motors and generators are well known and understood. Typically, such permanent magnet machines include a rotor formed, at least in part, from a magnetic material such as Samarium-Cobalt. Electric windings on a stator about the rotor are used to carry current that either generates a magnetic field or is the result of a magnetic field about the rotor. As a motor, current through the windings induces the rotating magnetic field, which in turn applies a torque to the magnetic portion of the rotor causing it to act as motor. Similarly, as a generator, torque applied to the rotor, results in a rotating magnetic field that induces a current in the windings.
[0003] Such electric machines provide significant benefits over synchronous machines, squirrel cage motors and other types of electric machines. Significantly, permanent magnet machines do not require brushes; are relatively light; use conventional and developed electronics to generate any required rotating magnetic field; and can act as both motors and generators.
[0004] In view of these benefits, such machines appear well suited for aircraft applications. Particularly, such machines would appear to lend themselves for use as starters and generators within a turbine engine.
[0005] Conveniently, such machines can be connected directly to the engine shaft. When required, generated electricity can be rectified and filtered using conventional lightweight electronics. When DC currents are required, as in traditional aircraft applications, the speed of rotation and frequency of generator output does not need be controlled. Heavy gearing is therefore not required. Operating as motors, such machines can act as starters.
[0006] Disadvantageously, however, machines coupled to such engines can potentially generate extreme power limited only by the power of the turbine engine driving the rotor of the machine, Unabated, generation of such electric power can result in extreme heat, particularly in the stator windings, that may cause the motor to melt and potentially burn. This is clearly undesirable. Obviously, current provided by the machine to interconnected electrical equipment may be limited by fusing the interconnected equipment or even the electronics used to rectify or regulate AC currents. However, such fusing will not react to short circuits internal to the machine. While unlikely, such short circuits might, for example, occur in the stator windings. Should this happen, a permanent magnet machine will invariably overload and overheat causing damage to the machine, and perhaps even to the associated engine. In the extreme case, this may cause the main engine to fail as a result of the high temperature of the engine shaft coupled to the motor. Similar problems may be manifested in other types of electric machines.
[0007] Accordingly, an improved electric machine that is thermally protected is desirable.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, an electric machine includes a ferrite portion, forming part of its rotor or stator that loses its magnetic characteristics above a certain chosen temperature. As a result, any magnetic flux circulating between the rotor and stator is significantly reduced above this temperature, and the machine stops acting as generator. The component is thermally coupled to windings carrying current from the machine's stator. The material forming the component is selected so that the certain temperature is lower than the temperature at which the machine would be thermally damaged. This, in turn, limits the operating temperature of the windings, and thus preventing overheating of the machine during operation.
[0009] In accordance with an aspect of the present invention an electric machine includes a permanent magnet motor and a stator mounted about the rotor, at least partially forming a magnetic circuit guiding a magnetic flux emanating from the permanent magnet. At least one winding extends about the stator for picking up a current induced by the magnetic flux. At least a portion of the magnetic circuit is thermally coupled to the winding and is formed from magnetic material having a Curie temperature below a temperature at which the machine is damaged. This limits the magnetic flux about the magnetic circuit above the Curie temperature, and thus limits the operating temperature of the windings, and prevents overheating of the machine during operation.
[0010] In accordance with another aspect of the invention, an electric generator includes a rotor assembly including a permanent magnet; and a stator formed of a ferrite material mounted about the rotor, at least partially forming a magnetic circuit guiding a magnetic field emanating from the permanent magnet. At least one winding extends about the stator for picking up a current induced by the magnetic field. Preferably, the ferrite material is a Manganese-Zinc ferrite material.
[0011] Other aspects and features of the present invention will become apparent to those of ordinary skill in the art, upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In figures which illustrate, by way of example only, preferred embodiments of the invention,
[0013] [0013]FIG. 1 is an exploded view of a permanent magnet machine, exemplary of an embodiment of the present invention;
[0014] [0014]FIG. 2 is a cross sectional view of the machine of FIG. 1;
[0015] [0015]FIG. 3 is an exploded view of a partial stator assembly that may form part of the machine of FIG. 1;
[0016] [0016]FIG. 4 is a side perspective view of an exemplary stator assembly forming part of the machine of FIG. 1;
[0017] [0017]FIG. 5 is a back end view of FIG. 4;
[0018] [0018]FIG. 6 is a front end view of FIG. 4;
[0019] [0019]FIG. 7 schematically illustrates the flow of current about the stator assembly of FIG. 4; and
[0020] [0020]FIG. 8 is a top view of a portion of a further stator that may be used with a machine exemplary of a further embodiment of the present invention.
DETAILED DESCRIPTION
[0021] [0021]FIGS. 1 and 2 illustrate a permanent magnet electric machine 10 , exemplary of an embodiment of the present invention. As illustrated, electric machine 10 includes a stator assembly 12 and rotor assembly 14 , preferably mounted within a housing 16 . Rotor assembly 14 is mounted for free rotation about its central axis within housing 16 by bearings 20 and 22 .
[0022] Housing 16 includes an outer cylindrical shell 24 , and generally disc shaped front and rear end plates 26 and 28 . End plates 26 and 28 are fixed to shell 24 , and thereby retain stator assembly 12 , rotor assembly 14 , and bearings 20 and 22 within housing 16 . Annular walls 30 and 32 extend inwardly from the interior of end plates 26 and 28 and retain bearings 20 and 22 at defined axial positions within housing 16 , about rotor assembly 14 . A further retaining washer 23 assists to retain bearings 20 and 22 . Housing 16 is preferably formed of high-grade stainless steel.
[0023] Example rotor assembly 14 includes a generally cylindrical core section 38 . Two smaller diameter cylindrical shafts 34 and 36 extend axially outward from core section 38 , toward the front and rear of housing 16 , respectively. Spacing ledges 42 , 44 and 46 , 48 separate shafts 34 and 36 , respectively, from core section 38 . Ledges 42 and 46 abut with bearings 20 and 22 . A further smaller diameter concentric drive shaft 40 extends axially outward from shaft 34 and the front of housing 16 . As will be appreciated, core section 38 ; shafts 34 , 36 and 40 are preferably machined from a single piece of relatively low strength magnetic steel, such as maraging steel. A thin shell 18 formed of non-magnetic material, such as a Nickle alloy, at least partially encapsulates core section 38 and contains the relatively low strength magnetic steel. Shell S 1 is preferably formed of AMS 5662 or AMS 5663 Nickel Alloy and may be shrink fitted to the core portion 38 and then ground to achieve a desired overall thickness of shell 18 .
[0024] Stator assembly 12 is further illustrated in FIGS. 3 - 7 . As illustrated, stator assembly 12 includes a magnetic circuit defined by an exemplary hollow cylinder 50 . Cylinder 50 includes a plurality of lengthwise extending, evenly spaced slots 52 a , 52 b and 52 c (collectively slots 52 ) extending on its interior. In the preferred embodiment, a total of eighteen such slots extend along the cylinder's length. Conveniently, the eighteen slots 52 a , 52 b and 52 c may be grouped into three groups, with all slots 52 a belonging to one group, all slots 52 b and 52 c to another. Each third slot belongs in one of the groups. As best illustrated in FIG. 3, a set of six rectangular conductors 54 a that are complementary in shape to slots 52 a , occupy the entire length of these slots. Each of these conductors is formed of a material such as copper, and is insulated by a thin plastic coating. Each of conductors 54 a is identical in length, and extends slightly beyond the ends of cylinder 50 . Adjacent conductors within the group of conductors 54 a are interconnected by arced conductors 56 a extending radially about the central axis of cylinder 50 , and exterior to cylinder SO. Alternating pairs of conductors 54 a are connected at opposite ends of cylinder 50 . Thus, two arced conductors 56 a are at one end of cylinder 50 and three are at the opposite. Conductors 54 a and 56 a thus form an electric circuit (referred to as circuit 58 a ) traversing the length of cylinder 50 six times, at intervals spaced sixty degrees about a central axis of cylinder 50 . Diametrically opposed rectangular conductors (ie. spaced by one-hundred and eighty degrees) have currents running in opposite direction along the length of cylinder 50 and thus form current loops or windings about the central axis of machine 10 . As illustrated in FIGS. 4 - 6 , conductors 54 b , 56 b and 54 c , 56 c are similarly arranged to occupy the remaining slots 52 b and 52 c , and thus form circuits 5 b and 55 c . Resulting circuits 58 a , 58 b and 58 c (collectively circuits 58 ) thus form nine current loops or windings about central axis of machine 10 . As illustrated in FIG. 6, conductors 54 b and 54 c have the same length as conductors 54 a and are arranged at axial positions so that conductors 54 a , 54 b , 54 c (collectively conductors 54 ) and 56 a , 56 b and 56 c (collectively conductors 56 ) are not in contact with each other Moreover, these conductors are preferably insulated so that they are not electrically connected with cylinder 50 , and are thermally coupled to cylinder 50 . The conductors may be coupled to cylinder 50 by way of a known thermal conductive varnish or epoxy. Cylinder 50 and conductors 54 may be encapsulated using this varnish or epoxy. Contact points for each circuit 58 a , 58 b and 58 c extend from the rear end of cylinder 50 , as illustrated in FIG. 5. Current flow in circuits 58 a , 58 b and 58 c as viewed at the rear of machine 10 , resulting from a potential difference across the contact points is schematically illustrated in FIG. 7.
[0025] As illustrated, stator assembly 12 and cylinder 50 are coaxial with core section 38 . A small air gap separates core section 38 from cylinder 50 .
[0026] A conventional three phase circuit (not shown) may be used to drive circuits 58 a , 58 b and 58 c to cause machine 10 to act as a motor. Specifically, driving circuits 58 results in a rotating magnetic field generated by the nine windings or current loops, travelling circumferentially within cylinder 50 . This field is guided by cylinder 50 acting as part of a magnetic circuit about the center axis of this cylinder 50 , and in turn the core section 38 of rotor assembly 14 . As will be appreciated by those of ordinary skill in the art, the rotating magnetic field exerts a torque on the magnetic portion of rotor assembly 14 , causing it to rotate.
[0027] Cylinder 50 is preferably formed of a ferrite material. As is understood by those of ordinary skill in the art, ferrite materials exhibit magnetic properties and have high relative permeability resulting in low magnetic reluctance, allowing such materials to guide magnetic flux. Ferrites typically have cubic crystalline structure with the chemical formula MO.Fe 2 O 3 , where MO is typically a combination of two or more divalent metals, such as zinc, nickel, manganese or copper. Ferrites are typically classified as “hard” or “soft”. “Soft” ferrite materials only exhibit significant magnetic characteristics in the presence of a magnetic field, while “hard” ferrite materials tend to permanently retain their magnetic characteristics. As is further, understood, the nature of most magnetic materials is typically temperature dependent. Most magnetic materials lose their magnetic properties above a critical temperature, referred to as the Curie temperature of the material. For many materials, and for most ferrites, once the temperature of the material drops below the critical temperature, their magnetic properties return. Iron, for example, has a Curie temperature of about 770° C. In fact, most magnetic materials used in electric machines have Curie temperature far exceeding the operating temperature of the machine, In machine 10 , however, cylinder 50 and hence the magnetic circuit defined by cylinder 50 is formed of a material (preferably a ferrite) having a Curie temperature above conventional operating temperatures, but below a critical temperature at which damage might be caused to the circuits 58 or the remainder of machine 10 . For reasons that will become apparent, this Curie temperature may be considered to be the desired shut-down temperature of machine 10 . Preferably, cylinder 50 is formed of a “soft” ferrite having a Curie temperature of approximately 200° C. A ferrite having such property is, for example, a Manganese-Zinc available from Phillips under material type 3C85, having a Curie temperature of 215° C. Of course, other materials may be suitable, and will be easily identified by those of ordinary skill in the art. Preferably the material will have a Curie temperature between 95° C. and 300° C. depending on the desired shut-down temperature. Of course, some machine designs may require lower or higher shut-down temperatures.
[0028] In operation then, circuits 58 may be driven by a three-phase power source, as describe above, causing machine 10 to act as a motor. Instead of using an alternating current three-phase power source, each of circuits 58 a , 58 b and 58 c may be driven by a square wave source, with each square way source out of phase with a another square wave source by 120°. As will be appreciated, this has the same effect of using a poly-phase AC source, driving rotor assembly 14 .
[0029] More significantly, however, machine 10 may be operated as a generator by driving shaft 40 using a rotational source of mechanical power. For example, shaft 40 may be interconnected with the power shaft of a gas turbine engine, and driven at very high speeds (potentially in excess of 100,000 rpm). As will be appreciated, rotating rotor assembly 14 , and more particularly magnetic shell 18 will generate a rotating magnetic field about the central axis of rotor assembly 14 . This, in turn, establishes an alternating magnetic flux in the magnetic circuit defined by cylinder 50 . This flux, in turn, induces an electric current in the windings defined by circuits 58 a , 58 b and 58 c . As will be appreciated, the current so generated will be three-phase current, having a frequency proportional to the speed of rotation of rotor assembly 14 , with current through circuits 58 a , 58 b and 58 c being out of phase with each other by 120°. If desired, this current may be rectified using a conventional rectification circuit (also not shown).
[0030] Now, in the event machine 10 is subject to an internal fault, such as for example, caused by a short across conductors 54 or 56 , current in the conductors will increase, resulting in increased heat in the conductors, Moreover, as conductors 54 , and 56 are preferably in physical contact with, and thermally coupled to cylinder 50 , increase in temperature of conductors 54 or 56 will be transferred to cylinder 50 . As the temperature of cylinder 50 approaches the Curie temperature of the material forming cylinder 50 , cylinder 50 loses its magnetic properties, thereby severely limiting the flux through cylinder 50 and the current induced in the windings formed by circuits 58 , and effectively shutting down machine 10 acting as a generator. Clearly, as the current is reduced, the temperature of the conductors is reduced until the temperature of cylinder 50 again drops below the curie temperature of the material and its magnetic properties return. As will be apparent, in steady state and in the presence of a fault, machine 10 will operate with cylinder 50 at or near the selected shut-down or Curie temperature. Clearly, for a properly chosen Curie temperature, cylinder 50 acts as temperature activated fuse, limiting the operating temperature of machine 10 , and thereby any damage to its components.
[0031] Additionally, the use of ferrite material in the formation of stator assembly 12 advantageously reduces Hysteresis and Eddy current losses within stator assembly 12 . This becomes particularly beneficial at high speeds.
[0032] In yet another embodiment, rotor assembly 14 may include a material having the desired shut-down Curie temperature. Preferably, a ferrite material in placed radially outward of magnets forming part of rotor assembly 14 , effectively as part of the magnetic circuit formed coupling the flux from rotor assembly 14 to stator assembly 12 . Cylinder 50 may be formed of a material having a much higher Curie temperature, The ferrite material on rotor assembly 14 may then be thermally coupled to the conductors forming circuits 58 . These conductors, could for example, be coupled to rotor assembly 14 by radiation or convection. In the event that the temperature of these conductors increases, the increase in temperature is conducted to the ferrite portion of the rotor assembly 14 , thereby causing the ferrite material to lose its magnetic properties near the Curie temperature, This results in a portion of the magnetic circuit about the magnets of rotor assembly 14 having a very low permeability, thereby reducing the magnetic flux emanating with rotor assembly and coupled to cylinder 50 ; the resulting flux in cylinder 50 ; and the resulting current in circuits 58 . Again, at steady state this second embodiment will operate with the temperature of the windings and rotor at or near the selected shut-down or Curie temperature.
[0033] In a further embodiment, a cylinder 50 ′ illustrated in FIG. 8 may form part of a machine that is otherwise identical to machine 10 , may be formed of more than one material. A portion 62 of the cylinder 50 , of cylinder 50 is preferably formed of ferrite material having the desired shut-down Curie temperature, and the remaining portion 64 of the cylinder formed of a material having a different Curie temperature. For example the toothed portion (ie. the lengthwise extending teeth or ridges) of cylinder 50 ′ may be formed of laminated iron, while the remainder of cylinder 50 ′ may be formed of Manganese-zinc having a Curie temperature of about 200° C. individual iron teeth or ridges may be epoxied to a Manganese-Zinc portion. Above the Curie temperature, the resulting magnetic circuit would have a very high reluctance, severely limiting the magnetic flux guided about rotor assembly 14 , and therefore the current through windings about the cylinder 50 ′, again causing cylinder 50 ′ to operate at or near the chosen Curie temperature. Of course, other configurations of cylinder 50 ′ having other portions formed of a magnetic material having the desired Curie temperature will be readily apparent to those of ordinary skill in the art.
[0034] Clearly, the above embodiments may be modified in many ways while still embodying the invention, For example, the shape of cylinder 50 could be modified—a toroid or other shape could take its place; the arrangements of conductors and windings could be changed in any number of known ways; the permanent magnet of rotor assembly 14 can be formed in numerous ways; and the size of the machine can be scaled (increased or decreased) as required; other magnetic materials having suitable Curie temperature may be used. Thus it is apparent that the described invention may be embodied in many ways. As further examples, the invention could be embodied in a salient pole DC machine; or in a synchronous machine.
[0035] The above described embodiments, are intended to be illustrative only and in no way limiting. The described embodiments of carrying out the invention, are susceptible to many modifications of form, size, arrangement of parts, and details of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.
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An electric machine including a magnetic component, forming part of its rotor or stator that loses its magnetic characteristics above a certain chosen temperature is disclosed. This magnetic material forms part of a magnetic circuit that guides flux about the stator. As a result, any magnetic flux emanating with the rotor stops circulating about the stator above this temperature, and the machine stops acting as generator. The component is thermally coupled to windings carrying current from the machine's stator. The material forming the component is selected so that the chosen temperature is lower than the temperature at which the machine would be thermally damaged. This, in turn, limits the operating temperature of the windings, and thus prevents overheating of the machine during operation, typically caused by a fault. Preferably this magnetic material is formed from a ferrite material, such as a Manganese Zinc ferrite material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to pressure seals for use in oil well drilling strings and, more particularly, but not by way of limitation, it relates to an improved frangible sealing disk that may be used with packers, bridge plugs or the like as a break-away seal.
2. Description of the Prior Art
The prior art includes numerous types of sealing disks, both permanent and actuable, that may be used in conjunction with drill strings and related elements but such prior types of seals have not been of frangible construction but of permanent, hard materials that necessitated their physical removal from the drill string to release pressure flow. Nor has the prior type had a radial curvature to hold against pressure. This style also relieves problematic debris from falling into the wellbore.
SUMMARY OF THE INVENTION
The present invention relates to improvements in construction of drill or tubing string seals as used with packers, bridge plugs and the like, such improvement comprising constructing the seal of selected ceramics, a frangible material, in a precise arcuate shape offering maximum pressure resistance. Ideally, the frangible seal is a molded, arcuate configuration formed from a ceramic material obtained from the Coors Ceramic Company, which is employed in combination with an elastomer packing O-ring to isolate pressure either above or below a designated point in a tubing or drill string. When it is desired to remove the seal from the pipe string, it is only necessary to lower a breaking implement down the bore to strike the sealing disk and shatter it into pieces whereupon it will fall away down the bore of the pipe string leaving the bore open and communicating throughout.
Therefore, it is an object of the present invention to provide a borehole seal that is readily removable by breakage carried out by wielding a breaking implement within the borehole.
It is also an object of the present invention to form a seal out of frangible ceramic material that can be readily broken away to release the seal.
It is yet further an object of the invention to provide a ceramic seal in the form of an arcuate disk formed to present maximum strength to forces normal to tangential.
Finally, it is an object of the present invention to provide an arcuate ceramic seal member for use in combination with a sealing O-ring to provide pressure isolation adjacent a bridge plug, packer or similar pressure isolation component.
Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings that illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view in elevation of a two way seal assembly in combination with a packer assembly;
FIG. 2 is a cross-sectional view of a first form of frangible seal;
FIG. 3 is a top plan view of the frangible seal of FIG. 2;
FIG. 4 is a top plan view of an alternative form of frangible seal;
FIG. 5 is a cross-sectional view of the frangible seal of FIG. 4;
FIG. 6 is an elevation of a frangible seal as utilized with a bridge plug shown in elevation with one side shown in cutaway section; and
FIG. 7 is a screw-on plug body shown in elevation with one side in cutaway section.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a pair of frangible disks 12 and 14 used in combination with a frac plug 10 to provide isolation against both uphole and downhole pressure. Each of the frangible disks 12 and 14 is employed in association with a respective elastomer sealing O-ring 16 and 18 disposed around respective curved, sloping portions of convex surfaces of disks 12 and 14 as shown in FIG. 1. A cylindrical plug body 20 of selected diameter defines a central bore with threads 22 for receiving a pipe or tubing stub 24 threadedly gripped by means of threads 26 to define the inner wall 28 and central bore 30. The opposite end of plug body 20 includes threads 32 and groove 34 with O-ring 36 for receiving one end 38 of cylinder 40 therein as secured by means of threads 42.
The plug body 20 is formed with an annular formation 44 at about the middle interior which includes annular shoulder surfaces 46 and 48 that function to support the lower faces 50 and 52, respectively, of frangible disk members 14 and 12. The lower frangible disk 14 is positioned and an O-ring 18 assumes a crushed seal attitude with insertion of comb 54 of end plug 24 thereby to maintain frangible disk 14 in tight seal. The opposite or upward facing frangible disk 12 is maintained in sealed seating by means of the crushed O-ring 16 as maintained seated by threaded insertion of cylindrical body 40 within threads 32 of plug body 20. Thus, in this case, ceramic disks 12 and 14 are utilized in a back-to-back relationship in what is termed a ceramic dome configuration.
The frac plug cylinder body 40 includes a selected type of lower slips 56 and upper slips 58 disposed therealong in circumfery, depending upon the type of slip formation. A combination packing element 60 is utilized with an 80 durometer packing sleeve 62 buttressed by respective lower and upper 90 durometer packing elements 64 and 66 positioned on each side. Finally, internal threads 68 within the plug body cylinder 40 provide connection to whatever the supporting assembly or string.
FIGS. 2 and 3 show a first form of frangible ceramic disk 12 such as that utilized in the dome combination of FIG. 1. The disk 12 is formed with a dome of predetermined radius of curvature 67 that provides maximum strength to forces normal to tangential, and terminates in a lower circumferential comb 68 having circular seating face 52 with all corners finished sharp, i.e., without chamfer. A ceramic disk of this configuration would be suitable for sealing of a 4.5 inch outside diameter frac plug rated at 6,000 psi and 200° F.
FIGS. 4 and 5 show an alternative formation of ceramic disk 70 having similar properties and a curvature radius 72 of 1.321R±0.032 inches, but having a 45° chamfer around the circular seating face 74. The ceramic disks are made by Coors Ceramic Company using Coors technical specification No. 800-900-001 which designates the guidelines for dimensional tolerancing and visual criteria.
Referring to FIG. 6, the packer assembly 80 incorporates a ceramic disk pressure seal 82 in a different manner. The packer 80 includes a bore 84, upper slips 86 and an array of packing elements 88 as supported on a cylindrical body 90. The cylinder body 90 includes bottom threads 92 for receiving a threaded capture sub 94 thereon. The capture sub 94 consists of an upper enlarged portion having threads 96 for secure engagement on cylinder threads 92 while defining a cupped seating space 98 wherein the ceramic disk 82 is received for operative positioning. The capture sub 94 then extends on downward to expose external threads 100 albeit such threading is not necessary in certain applications. The ceramic disk 82 is positioned with the bottom edge surface held against a lower rim 102 of cylinder body 90 by means of the cup space 98 of the capture sub 94, and the central portion, i.e., the domed portion 104 of ceramic disk 82 is maintained centered over the central bore 106 defined by capture sub 94. The lower slips 108 of packer 80 are disposed immediately above the capture sub 94 and function in well-known manner.
FIG. 7 illustrates a screw-on plug 110 that may be used to provide the same function as capture sub 94. The bottom plug 112 defines a central bore 114 which is actually an annular shoulder having threads 118 formed thereabove and defining an annular shoulder 116 facing downward. The plug body 112 includes internal threads 118 which may be secured on threads 92 of the cylinder body 90 (see FIG. 6) to secure the lower region of the packer 80. A selected ceramic disk 120 may then be secured beneath annular surface 116 by means of a securing ring 122 which extends a securing ring upward for threaded engagement within the lower rim 124 of plug 112. Here again, the ring 122 defines a central bore 126 which exposes a large part of the dome surface 128 of ceramic disk 120. Such a plug 110 may be used for securing a downwardly directed ceramic disk 128 to withstand downhole pressures.
The bottom plug 112 may also be constructed to seat a ceramic dome type of seal. That is, a double up and down seal as illustrated in the FIG. 1 embodiment. The necessary dome seating structure could readily be molded into the seal seating arrangements or plugs accommodating such ceramic dome seals.
In operation, any of the ceramic disks, whether directed downhole or uphole to withstand incident pressures, is frangible to simply allow a striking implement lowered in the bore to break the ceramic disk centrally such that the constituent parts fall away down the string bore. Thus, there is no necessitation for special implements, withdrawal of the assembly, or in any way working of the drill string to relieve the pressure block by removing the seal.
The foregoing discloses a ceramic disk that is capable of withstanding elevated pressures and temperatures that may be encountered in downhole drilling situations. Further, use of the ceramic disk alleviates any problems inherent with subsequent releasing of the pressure block since it is only necessary to lower an instrument down the borehole and to break out the center of the ceramic disk while allowing the fragments to fall harmlessly down the borehole thus avoiding any accumulation of metal plates or other blockage implements at the site.
Changes may be made in the combination and arrangement of elements as heretofore set forth in the specification and shown in the drawings; it being understood that changes may be made in the embodiments disclosed without departing from the spirit and scope of the invention as defined in the following claims.
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A frangible sealing disk for use downhole in combination with packer components. The sealing disk is a molded ceramic disk having a circular seating face and extending centrally through a dome-shaped seal. The seal is preferred for use in combination with a packer assembly for pressure sealing the borehole, either up hole or down, so that the seal may be broken away easily when it is desired to remove or reset the packer assembly.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a projection exposure apparatus which is used for the purpose of forming a fine pattern in production of LSIs.
2. Description of the Related Art
FIG. 46 shows a known projection exposure apparatus. This known apparatus has a fly-eye lens 3 which is disposed to confront the front side of the lamp house 1 across a mirror 2. An aperture member 4 is disposed in front of the fly-eye lens 3, and an exposure mask 8 having a desired circuit pattern is disposed to face the aperture member 4 across condenser lenses 5, 6 and a mirror 7. A wafer 10 is disposed in front of the mask 8 so as to oppose the latter across a projection lens system 9. As will be seen from FIGS. 47 and 48, the aperture member 4 has a disk-like member having a central circular aperture 4a.
Light emitted from the lamp house 1 impinges upon the fly-eye lens 3 through the mirror 2, so as to be divided into regions corresponding to the elementary lenses 3a which form the fly-eye lens 3. The light components which have passed through the elementary lenses 3a illuminate the whole region of the mask 8 through the aperture 4a of the aperture member 4, condenser lens 5, mirror 7 and the condenser lens 6. Thus, the light components from the elementary lenses 3a are superposed one on another to uniformly illuminate the mask 8. The light which has passed through the mask 8 reaches the wafer 10 past the projection lens system 9, whereby a circuit pattern is printed on the surface of the wafer 10.
It is well known that, in projection exposure apparatus of the kind described, the minimum resolution R is proportional to λ/NA, where λ represents the wavelength of the light employed and NA represents the aperture number of the optical system. Hitherto, therefore, design of the optical system has been done in such a way as to employ a large aperture number NA so as to enhance the resolution of the projection exposure apparatus, thus coping with the current demand for higher degree of scale of integration of LSI circuits.
Increase in the aperture number NA in one hand improves the resolution, i.e., reduces the minimum resolution R bur on the other hand reduces the depth of focus DOF of the projection exposure apparatus. The focal depth DOF is proportional to λ/NA 2 In the known projection exposure apparatus, therefore, an increase in the aperture number NA for improving the resolution is inevitably accompanied by degradation of the transfer precision due to reduction in the focal depth.
FIG. 49 illustrates a light source image formed in the pupil 9a of the projection lens system 9 when the circuit pattern of the mask 8 has parallel-line pattern of a minuteness level approximating the resolution limit. A light source image S 0 is formed by the 0-order light on the center of the pupil 9a, while light source images S 1 and S 2 are formed by first-order light on both sides of the light source image S 0 . For instance, the light L 0 passing through the center of the 0-order light source image S 0 interferes with the lights L 1 and L 2 passing through the centers of the fist-Order light source images S 1 and S 2 so as to form a pattern on the wafer 10. The aperture number NA is given by sin θ 1 , representing the angle of incidence of each of the lights L 1 and L 2 on the wafer 10 by θ, Consequently, the focal depth DOF decreases as the angle of incidence of the light to the wafer 10 increases.
In order to avoid reduction in the focal depth DOF, Japanese Patent Laid-Open No. 61-91662 discloses a projection exposure apparatus which employs a ring-shaped aperture member. In this art, as shown in FIG. 50, the lights L 0 to L 2 passing through the centers of the respective light-source images S 0 to S 2 are interrupted by the aperture member Consequently, lights passing through the peripheral portions of the pupil 9 are interrupted in the region near the resolution limit, the angle θ 2 of incidence of lights to the wafer 10 is reduced to offer an appreciable improvement in the focal depth DOF. Referring to FIG. 50, however, the lights L 4 and L 5 , among the lights L 3 to L 5 passing through the upper edges of the light source images S 0 to S 2 which are directed to regions outside the pupil 9a are interrupted by the pupil 9a. Consequently, the light L 3 of the 0-order light source image S 0 merely contributes to illumination of the background, without being focused in the wafer 10. Consequently, the contrast of the image is seriously impaired to deteriorate the transfer precision.
Referring to FIG. 51, there are shown lights L 6 to L 8 which pas through left portions of the light source images S 0 to S 2 , among which the light L 8 of the -1-order light source image S 2 is interrupted by the pupil 9a. Consequently, the light L 6 of the 0-order light source image S 0 interferes only with the light L 7 of the +1-order light source image S 1 , so as to form an image on the wafer 10. Similarly, the light passing through the hatched region Q 0 of the 0-order light source image S 0 interferes only with the light passing through he hatched region Q 1 of the +1-order light source image S 1 , and the light passing through the right hatched region R 0 of the 0-order light source image S 0 interferes only with the light passing through he hatched region R 2 of the -1-order light source image S 2 , Thus, in the hatched areas Q 0 , Q 1 , R 0 and R 1 , one of the light of the +1-order light source image S 1 and the light of the -1-order light source S 2 cannot make contribution to the formation of the image.
It is assumed here that the mask 8 has a line-and-space circuit pattern having light-interrupting portions 8a and light-transmitting portions 8b having the same width, as shown in FIG. 52. In such a case, the 0-order light source image S 0 has an amplitude T 0 of 0.5, while the amplitudes T 1 and T 2 of the -1-order light source images S 1 and S 2 are 063/2. In FIG. 51, the amplitudes T0 to T2 are represented by thickness of the disks which indicate the light source images S 0 to S 2 . Am optical image with large amplitude E is advantageously obtained as shown in FIG. 53 when all the light source images S 0 to S 2 having amplitudes T 0 to T 2 contribute to the formation of the image. However, when one of the lights of the +1-order light source image S 1 and the light of the -1-order light source image S 2 do not contribute to the formation of the image, only a small amplitude F of the optical image is obtained, resulting in an inferior contrast of the image.
FIGS. 54 and 55 show Levenson type phase shift mask. This mask has a transparent substrate 8c on which provided at a constant pitch are parallel Cr light-interrupting members 8d so that light-transmitting portion and shading portion are formed alternately. Phase shift members 8e of for example, SOG are formed in every other light-transmitting portions. When this type of phase shift mask is used, in the region where the phase shift member 8e and the transparent substrate 8c neighbor each other as viewed on the planar pattern, the light which has been transmitted both through the phase shift member 8e and the transparent substrate 8c and the light which has passed only through the transparent substrate 8c interfere with each other, so that the light intensity is reduced to zero. Therefore, when a positive resist is used, the pattern on the wafer is partly deformed as at 10b so that the patterns 10a to be formed by the light interrupting members 8d are undesirably connected, resulting in an impaired transfer accuracy.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a projection exposure apparatus which can provide higher transfer precision, thereby overcoming the above-described problems of the prior art.
To this end, according to the present invention, there is provided a projection exposure apparatus, comprising: a light source; a light condensing optical system through which light from the light source is condensed and applied to a mask carrying a circuit pattern; a projection lens system which projects the light transmitted through the mask onto the surface of a wafer; and an aperture member which is interposed between the light source and the light condensing optical system; wherein the aperture member has a light transmission region for transmitting the light from the light source and a light-interrupting member disposed to extend across the light transmission region.
The light-interrupting member used in the aperture member can have various forms such as belt-like form, bobbin-like form, cross-form centered at the center of the transmission region and radial form centered at the center of the transmission region.
The arrangement may be such that the aperture member has belt-like first and second light-interrupting members which extend across the transmission region passing the center of the latter and which are rotatable about the center of the transmission region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of an optical system incorporated in the first embodiment of the projection exposure device of the present invention;
FIG. 2 is a plan view of an aperture member used in the first embodiment;
FIG. 3 is a sectional view taken along the line A--A of FIG. 2;
FIG. 4 is an illustration of the relationship between a light source image formed on the pupil of a projection lens system and the angle of incidence of light to a wafer, as obtained when the aperture member of FIG. 2 is used together with a mask having a circuit pattern which is a parallel-line pattern approximating resolution limit;
FIGS. 5 to 10 are plan views of aperture members use din the second to seventh embodiments;
FIG. 11 is an illustration of the relationship between a light source image formed on the pupil of a projection lens system and the angle of incidence of light to a wafer, as obtained when the aperture member of FIG. 10 is used together with a mask having a circuit pattern which is a parallel-line pattern approximating resolution limit;
FIGS. 12 to 15 are plan views of aperture members used in the eighth to eleventh embodiments;
FIG. 16 is a sectional view taken along the line B--B of FIG. 15;
FIG. 17 is a plan view of an aperture member used in a twelfth embodiment;
FIG. 18 is an illustration of the relationship between a light source image formed on a pupil of a projection lens system and angle of incidence to a wafer;
FIGS. 19 and 20 are plan views of aperture members used in thirteenth and fourteenth embodiments;
FIG. 21 is an illustration of the relationship between a light source image formed on a pupil of a projection lens system and angle of incidence to a wafer as observed when the aperture member shown in FIG. 20 is used;
FIGS. 22 and 23 are plan views of aperture members used in fifteenth and sixteenth embodiments, respectively;
FIG. 24 is an illustration of the relationship between a light source image formed on a pupil of a projection lens system and angle of incidence to a wafer as observed when the aperture member shown in FIG. 23 is used;
FIG. 25 is a plan view of an aperture member used in a seventeenth embodiment;
FIG. 26 is an illustration of a mask used in a eighteenth embodiment;
FIG. 27 is an illustration of a light source image formed on a projection lens system when the mask of FIG. 26 is used;
FIG. 28 is an illustration of the amplitude of the optical image formed on a wafer by the use of the mask shown in FIG. 26:
FIG. 29 is a sectional view of a mask used in a nineteenth embodiment of the present invention;
FIGS. 30 to 32 are sectional views of the masks used in 20th to 22nd embodiment and amplitudes of optical image son wafers;
FIG. 33 is a plan view of an aperture member used in the 23rd embodiment;
FIG. 34 is a plan view of a positive resist pattern on a wafer as obtained when the aperture member of FIG. 33 is used;
FIG. 35 is an illustration of the relationship between an optical image formed on the pupil of a projection lens system and angle of incidence to a wafer, as obtained when the aperture member of FIG. 33 is used;
FIGS. 36 and 37 are plan views of the aperture members used in 24th and 25th embodiments, respectively;
FIG. 38 is an illustration of the relationship between an optical image formed on the pupil of a projection lens system and angle of incidence to a wafer, as obtained when the aperture member of FIG. 37 is used;
FIGS. 39 and 40 are plan views of the aperture members used in 26th and 27th embodiments, respectively;
FIG. 41 is an illustration of the relationship between an optical image formed on the pupil of a projection lens system and angle of incidence to a wafer, as obtained when the aperture member of FIG. 40 is used;
FIGS. 42 and 43 are plan views of the aperture members used in 28th and 29th embodiments, respectively;
FIG. 44 is an illustration of the relationship between an optical image formed on the pupil of a projection lens system and angle of incidence to a wafer, as obtained when the aperture member of FIG. 43 is used;
FIG. 45 is a plan view of an aperture member used in the 30th embodiment;
FIG. 46 is an illustration of an optical system of a known projection exposure apparatus;
FIG. 47 is a plan view of an aperture member used in the apparatus of FIG. 46;
FIG. 4θis a sectional view taken along the line C--C of FIG. 47;
FIG. 49 is an illustration of the relationship between a light source image formed on the pupil of a projection lens system and the angle of incidence of light to a wafer, as obtained when the aperture member of FIG. 47 is used together with a mask having a circuit pattern which is a parallel-line pattern approximating resolution limit;
FIG. 50 is an illustration of the relationship between a light source image formed on the pupil of a projection lens system and the angle of incidence of light to a wafer, as obtained when a known aperture member is used together with a mask having a circuit pattern which is a parallel-line pattern approximating resolution limit;
FIG. 51 is an illustration of light source images formed on the pupil of a projection lens system when another aperture member is used;
FIG. 52 is an illustration of a shifter-shade type phase shift mask;
FIG. 53 is a graph showing the amplitude of light source image formed on a wafer with the use of the mask shown in FIG. 52;
FIG. 54 is a sectional view of a Levenson type phase shift mask;
FIG. 55 is a plan view of the mask shown in FIG. 54; and
FIG. 56 is a plan view of a wafer showing a positive resist pattern formed thereon when the mask of FIG. 54 is formed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 illustrates an optical system used in a first embodiment of the projection exposure apparatus of the present invention. The optical system includes a lamp house 11 for emitting light of a wavelength λ. Light from the lamp house 11 is reflected by a mirror 12 and impinges upon a fly-eye lens 13 on the emitting side of which is disposed an aperture member 21. The light passed through the aperture member 21 is made to impinge upon an exposure mask 18 carrying a desired circuit pattern, past condenser lenses 15, 16 and a mirror 17. A wafer 20 is disposed o oppose the mask 18 across a projection lens system 19. The lamp house 11, mirror 12 and the fly-eye lens 13 form a light source, while the condenser lenses 15, 16 and the mirror 17 form a condensing lens system.
As will be seen from FIGS. 2 and 3, the aperture member has a disk-shaped frame 22 having a central circular aperture 22a, a transparent member 23 which is formed to cover the entire area of the opening 22a in the frame 22 and a belt-like light-interrupting member 24 which is formed on a surface of the transparent member 23 so as to extend across the opening 22a in the frame 22. The opening 22a in the frame 22 defines a transmission region D which transmits light from the lamp house 11. The frame 22 and the light-interrupting member 24 may be formed of a metal such as aluminum, while the transparent member 23 may be formed of, for example, a sheet of glass. The light-interrupting member 24 may be formed by vacuum evaporation of the metal material on the transparent member 23.
A description will now be given of the operation of this embodiment. The light emitted from the lamp house 11 is reflected by the mirror 12 so as to impinge upon the fly-eye lens 13 so as to be divided into components corresponding to the elementary lenses 13a. The light components which have passed through the respective elementary lenses 13a are made to pass through the light transmission region D of the aperture member 21 to illuminate the entire area of the mask 18 past the condenser lens 15, mirror 17 and the condenser lens 16. Thus, the light components from the elementary lenses 13a of the fly-eye lens 13 are superposed on one another to uniformly illuminate the mask 18. The light then passes through the mask 18 to be focused on the wafer 20 past the projection lens system 19, whereby the circuit pattern is printed on the surface of the wafer 20.
FIG. 4 illustrates a light source image which is formed on the pupil 19a of the projection lens system 19 when the circuit pattern on the mask 18 is a parallel-line pattern of fineness approximating the resolution limit. A light source image S 0 is formed by the 0-order light on the center of the pupil 19a, while light source images S 1 and S 2 are formed on the left and right sides of the light source image S 0 by the 1-order lights, respectively. These light source images S 0 to S 2 have belt-like light-interrupted portions P 0 to P 2 which are formed by the light-interrupting member 24 of the aperture member 21. Assuming that the belt-like light-interrupting member 24 is parallel to the parallel-line pattern on the mask 18, the light-interrupted portions P 1 and P 2 of the 1-order light source images S 1 and S 2 are located On the periphery of the pupil 19a as shown in FIG. 4. Referring to FIG. 4, therefore, the lights L 0 to L 2 having axes on the centers of the light source images S 0 to S 2 and the lights L 3 to L 5 passing through the upper edge portions of the light source images S 0 to S 2 are interrupted by the light-interrupting member 24 of the aperture member 21. Consequently, the angle θ 3 of incidence to the wafer 20 is reduced to improve the focal depth DOF, whereas the lights which contribute only to illumination of the background are interrupted so as to avoid degradation of the contrast.
It is preferred that, a described above, the light-interrupting member 24 of the aperture member 21 is parallel to the parallel-line pattern on the mask 18. Therefore, when the mask 18 has a parallel-line pattern orthogonal to that of the first embodiment, it is recommended to use an aperture member 31 which has a laterally-extending light-interrupting member 41 as shown in FIG. 5.
When the mask has a composite pattern composed of two orthogonal parallel-line patterns, it is effective to use an aperture member 32 which has a cross-shaped light-interrupting member 42 centered at the center of the transmission region D. When these two orthogonal parallel-line patterns have different line pitches, an aperture member 33 of FIG. 7 is conveniently used which has a cross-shaped light-interrupting member 43 having vertical and horizontal portions of different widths.
When the mask 18 has oblique patterns in addition to two orthogonal parallel-line patterns, it is preferred to use an aperture member of FIG. 8 which has radial light-interrupting member 44 which is centered at the center of the light transmitting region D.
When the mask 18 has oblique patterns inclined at specific angles, e.g., 30° and 60°, it is advisable to use an aperture member 35 of FIG. 9 which has a light-interrupting member 45 composed of two belt-like portions which are inclined at the same angles as those of the mask pattern and which cross each other at the same angle as that in the mask pattern.
It is also possible to use an aperture member 36 of FIG. 10 which has a light-interrupting member 46 extending across the light-transmitting region D and having a bobbin-like form. FIG. 11 illustrates the light source image which is formed on the pupil 19a of the projection lens system 19 when the aperture member 36 of FIG. 10 is used together with the parallel-line pattern of a fineness approximating the resolution limit. As will be seen from FIG. 11, the lights L 0 to L 2 having optical axes on the centers of the light source images S0 to S2 and the light L3 to L5 passing through upper edge portions of the light source images S0 to S2 are interrupted by the light-interrupting member 46 of the aperture member 36. Consequently, the angle θ 4 of incidence to the wafer 20 is reduced to improve the focal depth DOF, whereas the lights which contribute only to illumination of the background are interrupted so as to avoid degradation of the contrast. By using a bobbin-shaped light-interrupting member 46, it is possible to effectively interrupt only the components of the light from the light source which act to impair the contrast of the optical image and the focal depth.
The aperture member having a bobbin-shaped light-interrupting member can have various modified forms in accordance with the pattern on the mask 18, such as an aperture member 37 with a horizontal light-interrupting member 47 as shown in FIG. 12, an aperture member 38 having a cross-shaped light-interrupting member 48 as shown in FIG. 13 and an aperture member 39 having cross-shaped light-interrupting member 49 having vertical and horizontal portions of different widths, as shown in FIG. 14.
FIGS. 15 and 16 show an aperture member 51 having first and second belt-like light-interrupting members 64 and 74 which are rotatable relative to each other. More specifically, this aperture member has a cylindrical casing 52 and first and first and second rotational members 61 and 71 which are rotatably encased by the casing 52. A flange 53 is formed on the upper side of he casing 52 so as to project inward from the inner peripheral edge thereof, and a circular aperture 54 defining the light transmitting region of the aperture member 51 is formed in the center of the lower wall of the casing 52. The first and second rotational members 61 and 71 have, respectively, disk-shaped frames 62 and 72 having central circular apertures 62a and 72a, transparent members 63 and 73 formed to close the entire areas of the apertures 62a an 72a, and belt-shaped light-interrupting members 64 and 74 which are formed on the surfaces of the transparent members 63 and 73 so as to extend across the apertures 62a and 72a. Levers 65 and 75 are secured to the frames 62 and 72 of the first and second rotational members 61 and 71, respectively, so as to project to the exterior of the casing 52.
The arrangement is such that the rotational members 61 and 71 are independently rotated within the casing 52 as the associated levers 65 and 75 are moved circumferentially. Thus, the first and second rotational members are rotatable about the center of the light-transmitting region D, thus enabling the control of the angles of the first and second light-interrupting members 64 and 74 in accordance with the pattern held by the mask 18. By using this aperture member 51, it is possible to obtain a projection exposure apparatus having a high degree of utility.
It is also possible to use an aperture member in which, as denoted by 81 in FIG. 17, the light-interrupting member 91 has such a spindle-like form as to extend transversely of the light transmitting region D. FIG. 18 shows a light source image which is formed on the pupil 19a of the projection lens system 19 when this aperture member 81 is used together with a mask 18 whose circuit pattern includes a comparatively coarse parallel line pattern. As will be seen from FIG. 18, each of the light source images S 0 to S 2 has spindle-shaped light-interrupted portion P 0 to P 2 and light-transmitted portions on both sides of the light-interrupting portion. The light-transmitted portions Al and A2 of the primary light source images S 1 and S 2 are cut by the pupil 19a of the projection lens system 19, so that the angle θ 5 of incidence to the wafer 20 is reduced. As a consequence, the depth of focus DOF is improved. The use of the aperture member 81 having the spindle-shaped light-interrupting member 91 offers an advantage particularly when the circuit pattern has a practical size.
When the mask 18 has parallel-line patterns which orthogonally cross each other, it is effective to use an aperture member 82 shown in FIG. 19 which has a spindle-and cross-shaped light-interrupting member 92.
It is also possible to use an aperture member 83 shown in FIG. 20 which has a mesh-like light-interrupting member 93 extending transversely of the transmitting region D. FIG. 21 shows the light source image formed on the pupil 19a of the projection lens system when this aperture member 83 is used with a mask 18 whose circuit pattern includes a comparative coarse parallel-line pattern. As will be seen from FIG. 21, each of the light source images S 0 to S 2 has spindle-shaped light-interrupted portion P 0 to P 2 and light-transmitted portions on both sides of the light-interrupting portion. The light-transmitted portions A 1 and A2 of the primary light source images S 1 and S 2 are cut by the pupil 19a of the projection lens system 19, so that the angle θ 6 of incidence to the wafer 20 is reduced. As a consequence, the depth of focus DOF is improved. In this case, since the light-interrupting member 93 is formed of a mesh member, the light-interrupting portions P 0 to P 2 also transmit light although the light quantity is small. It is possible to adjust the effect of the deformed light source method by using this feature. The use of the aperture member 83 having the mesh-type light-interrupting member 93 offers an advantage particularly when the circuit pattern has a practical size.
Although the light-interrupting member 93 shown in FIG. 20 has a spindle-like outer configuration, this is only illustrative and the light-transmitting member 93 can have any other suitable configurations such as belt-like form or bobbin-like form. In FIG. 20, the mesh of the light-interrupting member 93 is finer in the central region of the member 93 than in the peripheral region so as to enhance the light-interrupting effect in the central region of each light source image S 0 to S 2 . This, however, is not exclusive and the light-interrupting member 93 may have a uniform mesh size over the entire area thereof.
When the mask has parallel-line patterns which orthogonally cross each other, it is effective to use an aperture member θ4 having a cross-shaped meshed light-interrupting member 94 as shown in FIG. 22.
It is also possible to use an aperture member 85 shown in FIG. 23 which has a light-interrupting member 95 made of a light-absorption film extending transversely of the transmitting region D. The light-absorption film may be a silicon nitride film. FIG. 24 shows the light source image formed on the pupil 19a of the projection lens system when this aperture member 85 is used with a mask 18 whose circuit pattern includes a comparatively coarse parallel-line pattern. As will be seen from FIG. 24, each of the light source images S 0 to S 2 has spindle-shaped light-interrupted portion P 0 to P 2 and light-transmitted portions on both sides of the light-interrupting portion. The light-transmitted portions A 1 and A 2 of the primary light source images S 1 and S 2 are cut by the pupil 19a of the projection lens system 19, so that the angle θ 7 of incidence to the wafer 20 is reduced. As a consequence, the depth of focus DOF is improved. In this case, since the light-interrupting member 93 is formed of a light absorption film, the light-interrupting portions P 0 to P 2 also transmit light although the light quantity is small. It is possible to adjust the effect of the deformed light source method by using this feature. The use of the aperture member 85 having the mesh-type light-interrupting member 95 offers an advantage particularly when the circuit pattern has a practical size.
Although the light-interrupting member 95 shown in FIG. 23 has a spindle-like outer configuration, this is only illustrative and the light-transmitting member 95 can have any other suitable configurations such as belt-like form or bobbin-like form. In FIG. 23, the light-interrupting member 95 is designed to exhibit a greater light absorption in the central region of the member 95 than in the peripheral region, by being thickened at its central region, so as to enhance the light-interrupting effect in the central region of each light source image S 0 to S 2 . This, however, is not exclusive and the light-interrupting member 93 may have a uniform light absorption distribution over the entire area thereof.
When the mask has parallel-line patterns which orthogonally cross each other, it is effective to use an aperture member 86 having a cross-shaped light-interrupting member 96 made of a cross-shaped light absorption film as shown in FIG. 22.
The mask 18 may be of a type shown in FIG. 26 which has a circuit pattern formed by shifter-shade type phase shift member 182 formed on a transparent glass substrate 181. The phase shift member 182 is made from, for example, SOG. It is assumed that the phase shift member has such a thickness as to cause a phase differential amounting to half the wavelength λ of the light used in the projection exposure apparatus, and that a line-and-space pattern is formed in such a manner that the ratio of the width of the phase shift member 182 to the width of the portion of the transparent glass substrate 181 devoid of the phase shift member 182 is 1:3. In such a case, as shown in FIG. 27, the amplitude T 3 of the 0-order light source image S 0 is 0.5 and the amplitudes T 4 and T 5 of the +1-order light source image S 1 and the -1-order light source image S 2 are respectively 0.9/2. That is to say, by forming the circuit pattern from shifter-shade type phase shift members 182, it is possible to increase the amplitudes of the +1-order and -1-order light source images S 1 and S 2 by about 1.5 times as compared with the mask 8 of FIG. 39 composed of light-interrupting and transmitting portions, while maintaining the amplitude of the 0-order light source image S 0 at the same level. In FIG. 27, the amplitudes T 3 to T 5 of the light-source images S 0 to S 2 are represented by the thicknesses of the disks which indicate the light source images S 0 to S 2 , respectively.
As will be understood from FIG. 27, the light passing through the hatched region Q 3 of the 0-order light source image S 0 interferes only with the light passed through the hatched region Q 4 of the +1-order light source image S 1 , whereas the light passing through the right hatched region R 3 of the 0-order light source image S 0 interferes only with the light passing through the hatched area R 5 of the 1-order light source image S 2 , thus forming an image. That is, the 0-order light source image S 0 interferes only with the light of one of the +1-order light source image S 1 and the -1-order light source image S 2 . By forming the pattern on the mask 18 with the phase shift member 182 of shifter-shade type, the amplitude of the +1-order and -1-order light source images S 1 and S 2 are increased by about 1.5 times. Consequently, as shown in FIG. 28, the optical image formed on the wafer 20 has an amplitude G which is greater than the amplitude F obtained when the mask 8 of FIG. 52 is used, thus attaining an improvement in the image contrast, as well as in the transfer precision.
The ratio of the width of the phase shift member 182 as shown in FIG. 26 is only illustrative, and an equivalent effect is obtained by using a mask having a different value of the width ratio.
In addition, it is not always necessary that the circuit pattern on the mask is wholly composed of the phase shift members. For instance, as a mask 28 shown in FIG. 29, the arrangement may be such that, while a repetitional pattern is formed by the phase shift members 282 of shifter-shade type n the transparent glass substrate 281, the pattern in a sufficiently wide light transmission region is formed by an ordinary metal light-interrupting member such as Cr because in such a wide light-interruption region the influence of interference between the 0-order light and the lights of +1-order and -1-order is small.
It is possible to use a shifter-shade type mask of the type denoted by 100 in FIG. 30. This mask 100 has a transparent substrate 101 and a phase shifter member 102 of shifter-shade type formed thereon. Furthermore, a light-interrupting member 103 such as of Cr is formed on the peripheral edge portion of the phase shifter member 102. When this mask 100 is used, the amplitude of the transmitted light is proportional to the area of the hatched region of the amplitude distribution shown in FIG. 30. It is therefore possible to control the quantity of the light transmitted, by varying the size of the light-interrupting member 103.
It is possible to use a shifter-shade type mask of the type denoted by 110 in FIG. 31. This mask 110 has a transparent substrate 111 and a phase shifter member 112 of shifter-shade type formed thereon. Furthermore, a light-interrupting member 113 is formed on the center of the phase shifter member 112. When this mask 110 is used, the amplitude of the transmitted light is proportional to the area of the hatched region of the amplitude distribution shown in FIG. 31. It is therefore possible to control the quantity of the light transmitted, by varying the size of the light-interrupting member 113.
It is possible to use a shifter-shade type mask of the type denoted by 120 in FIG. 32. This mask 120 has a transparent substrate 121 and a phase shifter member 122 of shifter-shade type formed thereon through the intermediary of a halftone light-interrupting member 123, whereby a translucent pattern is formed. When this mask 120 is used, the amplitude of the transmitted light is proportional to the area of the hatched region of the amplitude distribution shown in FIG. 32. It is therefore possible to control the quantity of the light transmitted, by varying the size of the translucent pattern.
When a Levenson type phase shift mask shown in FIGS. 54 and 55 is employed, it is preferred to use an aperture member 131 shown in FIG. 33. This aperture member has a pair of light-transmitting portions 141 arranged in the center thereof in the direction Y shown in FIG. 33, while other portions interrupt light. By using this aperture member 131, it is possible to obtain different spatial coherency in X and Y directions. More specifically, coherency is higher in X direction than in Y direction.
The direction of the aperture member 131 is then set such that the direction Y in which the pair of light-transmitting portions 141 are arranged extend in parallel with the parallel-line pattern of the phase shift mask. This arrangement conveniently reduces the tendency of interference between the light which has passed both through the phase shift member 8e and the transparent substrate 8c and the light which has transmitted through the transparent substrate 8c alone, in the boundary region between the phase shift member 8e and the transparent substrate 8c of the phase shift mask shown in FIG. 55. Consequently, when a positive resist is used for example, it is possible to accurately form the pattern determined by the light-interrupting member 8d on the wafer 10, without any local deformation of the pattern, as will be seen from FIG. 34.
FIG. 35 shows a light source image which is formed on the pupil 19a of the projection lens system 19 when the above-described aperture member 131 is used. In this case, since a Levenson type phase shift mask is employed, light source images S 1 and S 2 of +1-order and -1-order are formed at positions closer to the center of the pupil 19a as compared with the case where a light-interrupting or shifter-shading phase shift mask is used. As a consequence, the angle θ 8 of incidence to the wafer 20 is reduced to improve the depth of focus DOF.
When the mask have parallel-line patterns orthogonal to each other, it is effective to use an aperture member 132 having two pairs of light-transmitting portions 142 arrange din X and Y directions, respectively, as shown in FIG. 36.
FIG. 37 shows an aperture member 133 in which an elongated rectangular light-transmitting portion 143 is formed in the center thereof. This aperture member 133 provides substantially the same effect as that produced by the aperture member 131 of FIG. 33. FIG. 38 shows a light source image which is formed on the pupil 19a of the projection lens system 19 when the above-described aperture member 133 is used. In this case, since a Levenson type phase shift mask is employed, light source images S 1 and S 2 of +1-order and -1-order are formed at positions closer to the center of the pupil 19a as compared with the case where a light-interrupting or shifter-shading phase shift mask is used. As a consequence, the angle θ 9 of incidence to the wafer 20 is reduced to improve the depth of focus DOF.
When the mask have parallel-line patterns orthogonal to each other, it is effective to use an aperture member 134 having a cross-shaped light-transmitting portion 144 as shown in FIG. 39
When the Levenson type phase shift mask has a fine parallel-line pattern, it is preferred to use an aperture member 135 shown in FIG. 40 having a central bobbin-shaped light-transmitting portion 145. FIG. 41 shows a light source image which is formed on the pupil 19a of the projection lens system 19 when the above-described aperture member 135 is used. In this case, since a Levenson type phase shift mask is employed, light source images S 1 and S 2 of +1-order and -1-order are formed at positions closer to the center of the pupil 19a as compared with the case where a light-interrupting or shifter-shading phase shift mask is used. As a consequence, the angle θ 10 of incidence to the wafer 20 is reduced to improve the depth of focus DOF.
When the mask have parallel-line patterns orthogonal to each other, it is effective to use an aperture member 136 having a bobbin-cross-shaped light-transmitting portion 146 as shown in FIG. 42.
In contrast, when the Levenson type phase shift mask has a coarse parallel-line pattern, it is preferred to use an aperture member 137 shown in FIG. 43 having a central spindle-shaped light-transmitting portion 147. FIG. 44 shows a light source image which is formed on the pupil 19a of the projection lens system 19 when the above-described aperture member 137 is used. In this case, since a Levenson type phase shift mask is employed, light source images S 1 and S 2 of +1-order and -1-order are formed at positions closer to the center of the pupil 19a as compared with the case where a light-interrupting or shifter-shading phase shift mask is used. As a consequence, the angle θ 11 of incidence to the wafer 20 is reduced to improve the depth of focus DOF.
When the mask have parallel-line patterns orthogonal to each other, it is effective to use an aperture member 138 having a spindle-cross-shaped light-transmitting portion 146 as shown in FIG. 45.
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A projection exposure apparatus for use in LSI production comprises a light source, a light condensing optical system through which light from the light source is condensed and applied to a mask carrying a circuit pattern, a projection lens system which projects the light transmitted through the mask onto the surface of a wafer, and an aperture member which is interposed between the light source and the light condensing optical system. The aperture member has a light transmission region for transmitting the light from the light source and a light-interrupting member disposed to extend across the light transmission region. The shape or configuration of the light-interrupting member is determined in accordance with the geometry of the circuit pattern formed on the mask.
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REFERENCE TO RELATED APPLICATIONS
This is a continuation of pending International Patent Application PCT/KR2012/008801 filed on Oct. 25, 2012, which designates the United States and claims priority of Korean Patent Application No. 10-2011-0146923 filed on Dec. 30, 2011, and Korean Patent Application No. 10-2012-0114735 filed on Oct. 16, 2012, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a thermoplastic polyurethane compound composition which is used to form a coating layer on the surface of yarn made of polyester, nylon, spandex or the like, and more particularly to a thermoplastic polyurethane compound composition, which is used to produce coated yarn by mixing thermoplastic polyurethane resin with additives, compounding the mixture in an extruder and coating the surface of yarn (made of polyester, nylon, spandex or the like) with the compounded thermoplastic polyurethane to form a coating layer, and to a method of producing coated yarn using the thermoplastic polyurethane compound composition.
BACKGROUND OF THE INVENTION
As is known, yarns that are used to make industrial blind or floor materials are made of polyester, nylon, spandex or the like. However, these yarns have low rigidity, and thus a coating layer is formed on the surface of the yarns. Coated yarn is produced by coating PVC or PP on the surface of yarn made of polyester, nylon, spandex or the like while passing the yarn through a coating machine, particularly the core of the coating machine, in a state in which the yarn is wound around bobbins on the shelf.
However, the coated yarn produced by the above-described method has disadvantages of low durability and abrasion resistance, as well as insufficient properties such as low mechanical strength and chemical strength. For this reason, industrial blind or floor materials made of the coated yarn cannot be used for a long period of time in industrial fields.
In addition, among prior art documents as described below, prior art document (Korean Patent Registration No. 10-0875709; hereinafter referred to “conventional technology”) discloses coated yarn produced by coating the surface of yarn with thermoplastic polyurethane and a non-slipping fabric made of the coated yarn.
However, in the case of the conventional technology, when thermoplastic polyurethane is used, productivity is reduced to the low viscosity of the thermoplastic polyurethane, and particularly, it is impossible to produce coated yarn having thin thickness. In addition, the surface of the coated yarn becomes glossy, and for this reason, an additional process for matting the surface is required.
PRIOR ART DOCUMENTS
Patent Documents
Document 1: Korean Patent Laid-Open Publication No. 10-2012-0078630 (entitled “polyester yarn and production method thereof; published on Jul. 10, 2012).
Document 2: Korean Patent No. 10-0875709 (entitled “non-slipping fabric comprising thermoplastic polyurethane-coated yarn; published on Dec. 23, 2008).
Document 3: Korean Patent Laid-Open Publication No. 10-2008-0028665 (entitled “apparatus of producing PVC-coated yarn using polyester yarn; published Apr. 1, 208).
Document 4: Korean Patent No. 10-0749311 (entitled “method for producing yarn”; published on May 16, 2007).
Document 5: Korean Patent No. 10-0752272 (entitled “method for producing coated yarn having glossy and metallic feeling and dice for use in production of yarn; published on Sep. 18, 2007).
SUMMARY OF THE INVENTION
The present invention has been made in order to solve the above-described problems occurring in the prior art, and it is an object of the present invention to provide a thermoplastic polyurethane compound composition, which is used to produce a coated yarn having high durability, abrasion resistance, mechanical strength and chemical strength by mixing thermoplastic polyurethane resin with various additives, compounding the mixture in an extruder, and coating the compounded thermoplastic polyurethane on the surface of yarn (made of polyester, nylon, spandex or the like) in a conventional extruder to form a coating layer, and a method of producing coated yarn using the thermoplastic polyurethane compound composition.
Another object of the present invention is to provide a thermoplastic polyurethane compound composition for coating yarn, which can be used in a wide range of applications, including blind or floor materials, sports goods and daily necessities, and a method of producing coated yarn using the thermoplastic polyurethane compound composition.
Still another object of the present invention is to provide a thermoplastic polyurethane compound composition for coating yarn, which comprises, in addition to thermoplastic polyurethane, a thickener that can increase the viscosity of coating solution to achieve a required discharge rate (preferably, a discharge rate of 600 m/min or higher, which makes it possible to increase productivity and produce yarns having a fineness of 1,000 denier or less), and a method of producing coated yarn using the thermoplastic polyurethane compound composition.
The present invention is characterized in that a thermoplastic polyurethane compound for coating yarn is prepared by compounding a thermoplastic polyurethane with a thickener and a processing aid, the color of the thermoplastic polyurethane compound may be reproduced by adding a master batch corresponding to a desired color, and a coated yarn having a desired thickness may be produced by coating the thermoplastic polyurethane compound on the surface of yarn made of polyester, nylon, spandex or the like in a conventional extruder.
In addition, the present invention is characterized in that the thickener that is used to prepare the thermoplastic polyurethane compound for coating yarn is any one selected from among inorganic materials, including silica, talc and calcium carbonate (CaCO 3 ).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a process of producing a thermoplastic polyurethane compound for coating of yarn according to a preferred embodiment of the present invention by mixing thermoplastic polyurethane with various additives and compounding the mixture in an extruder.
FIG. 2 shows a process of coating a thermoplastic polyurethane compound, obtained as shown in FIG. 1 , on the surface of yarn made of polyester, nylon, spandex or the like according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a thermoplastic polyurethane compound composition which is used to produce coated yarn, the composition comprising thermoplastic polyurethane and a thickener.
Hereinafter, preferred embodiments of the present invention will be described detail with reference to the accompanying drawings. In the following detailed description, exemplary embodiments for solving the technical problem of the present invention will be described. Embodiments other than the disclosed embodiments may also be contemplated according to the present invention.
The present invention provides a method capable of producing a coated yarn having excellent physical properties, the method comprising: preparing virgin thermoplastic polyurethane or collecting thermoplastic polyurethane scrap remaining after the manufacture of airbag patterns in footwear manufacturing processes or after processing of thermoplastic polyurethane; mixing the thermoplastic polyurethane with various additives; compounding the mixture in an extruder to prepare a thermoplastic polyurethane compound (hereinafter referred to as “TPU compound”) for coating yarn; and coating the TPU compound on the surface of yarn made of polyester, nylon, spandex or the like in a conventional extruder. The present invention also provides a thermoplastic polyurethane compound composition which is used to produce the coated yarn.
In the present invention, coated yarn having a desired color can be produced by adding a master batch corresponding to the desired color during production of the TPU compound for coating yarn. Moreover, a TPU compound for coating yarn, which has a desired hardness, can be prepared by controlling the content of raw material. In addition, the thickness of coated yarn can be reduced depending on the thickness of yarn made of polyester, nylon, spandex or the like.
Thus, the present invention provides a thermoplastic polyurethane compound composition, which is used to produce a coated yarn which has excellent durability and abrasion resistance and good mechanical strength and chemical strength due to the inherent physical properties of thermoplastic polyurethane, and thus can be used in a wide range of applications, including sports goods, daily necessities and industrial supplies. The present invention also provides a method of producing coated yarn using the thermoplastic polyurethane compound composition.
Hereinafter, the present invention will be described in detail with reference to preferred embodiments, but the scope of the present invention is not limited to these embodiments.
Embodiment 1
A method of producing coated yarn using thermoplastic polyurethane according to a preferred embodiment of the present invention is divided into the following two steps: a first step of preparing a TPU compound for coating yarn; and a second step of coating the surface of yarn with the TPU compound. The production method according to the present invention will now be described in further detail with reference to FIGS. 1 and 2 . The first step is a step of mixing thermoplastic polyurethane with various additives and compounding the mixture in an extruder to prepare a TPU compound for coating yarn and is specifically shown in FIG. 1 . The second step is a step of coating the TPU compound on the surface of yarn made of polyester, nylon, spandex or the like and is specifically shown in FIG. 2 .
1. Step of Preparing TPU Compound for Coating Yarn
As shown in FIG. 1 , this step comprises: 1) mixing thermoplastic polyurethane with various additives (preferably a thickener and a processing aid) and feeding the mixture into the hopper of a conventional compounding extruder; 2) melting, kneading and compounding the mixture in the cylinder of the compounding extruder at a temperature of 150˜250° C. and a pressure of 50-150 kgf; 3) cutting a coating solution (i.e., compounded thermoplastic polyurethane coating solution), discharged through the dice of the compounding extruder, in cooling water to form pellets; and 4) drying the formed thermoplastic polyurethane pellets at a temperature of 60˜80° C. for 4-6 hours and aging the dried pellets at a temperature of 30˜50° C. for 7 days or more.
Hereinafter, components that are used in the production of a TPU compound for coating yarn, that is, thermoplastic polyurethane, a thickener and a processing aid, will be described.
The thermoplastic polyurethane is a virgin thermoplastic polyurethane prepared by polymerizing aromatic isocyanate or aliphatic isocyanate with polyether polyol or polycarprolactone using short chain glycol (e.g., 1,4-butanediol) as a chain extender.
In the present invention, in addition to virgin thermoplastic polyurethane, thermoplastic polyurethane scrap remaining after the manufacture of footwear may also be used in the present invention. Specifically, either airbag scrap remaining after the processing of airbags for footwear or clear or semi-clear type thermoplastic polyurethane scrap is used.
In the present invention, a thickener is used during the preparation of a thermoplastic polyurethane coating solution in order to improve productivity and matting properties. As the thickener, silica powder or an inorganic material (e.g., talc or CaCO 3 ) that increases viscosity is used. The thickener that is used in the present invention may also be an alloy with a resin such as a styrene butadiene styrene (SBS) block copolymer, a styrene ethylene/butylene styrene (SEBS) resin, a polyacetal resin (POM) or a styrene acrylonitrile resin (SAN), which can impart compatibility with thermoplastic polyurethane.
In the present invention, a processing agent is also used in order to improve productivity. Specifically, the processing agent is montane wax or a fatty acid ester (C 5 -C 9 ) with pentaerythritol.
In addition, in the present invention, an adhesive additive is used after weaving of a mesh with coated yarn. The adhesive additive is an olefin (PE, PP, EVA, etc.)-based coupling agent (containing 2-20% maleic anhydride).
Table 1 below show the results of using silica as a thickener when producing coated yarn using thermoplastic polyurethane according to the present invention.
TABLE 1
TPU
Melt
Flow
Extru-
compound
index
beginning
sion
(product
(g/10
tempera-
Flow viscosity
work-
Silica
name)
min)
ture (° C.)
165° C.
170° C.
ability
content
ESTANE58277
19.58
155.2
30,950
10,830
Poor
0.0 phr
(Lubrizol)
AK-92A-4
13.50
154.6
34,380
12,030
Good
1.5 phr
AK-92A-5
8.45
156.5
40,570
14,930
Good
3.0 phr
As can be seen in Table 1 above, as the silica content increased, the melt index decreased and the flow viscosity increased, suggesting that silica showed a thickening effect. Also, it could be seen that the extrusion workability was good when the silica content was 1.5 phr or higher. Further, the product having a silica content of 3.0 phr showed good extrusion workability, but was difficult to apply, due to the occurrence of blooming.
Additionally, the product names “AK-92A-4” and “AK-92A-5” shown in Table 1 are TPU compounds for coating yarn, prepared by the composition and preparation method of the present invention. Preferably, these product names are TPU compounds for coating yarn, prepared using silica as a thickener. In addition, the product name “ESTANE58277 (Lubrizol)” shown in Table 1 is a compound for coating yarn, prepared according to the method of conventional technology.
Table 2 below shows components that are added to prepare TPU compounds (particularly “AK-92A-4” or “AK-92A-5” shown in Table 1) for coating yarn, and the composition ratio of the components.
TABLE 2
Composition of the
present invention
AK-92A-4 (wt %)
AK-92A-5 (wt %)
Footwear airbag scrap
50.0
50.0
Virgin TPU
43.0
41.5
Polyethylene-based
5.0
5.0
coupling agent
Silica (thickener)
1.5
3.0
Montane wax
0.2
0.2
Fatty acid ester
0.3
0.3
Table 3 below shows a composition between the physical properties of TPU compounds (particularly “AK-92A-4” and “AK-92A-5” shown in Table 2) for coating yarn, prepared by the composition and preparation method of the present invention, and the physical properties of a compound for coating yarn (e.g., “ESTANE58277 (Lubrizol) shown in Table 1), prepared by conventional technology.
TABLE 3
Compound
according to
conventional
TPU compounds of
technology
Product
the present invention
ESTANE58277
name
AK-92A-4
AK-92A-5
(Lubrizol)
Remarks
TPU melt
13.5
8.45
15.2
200° C., 2.16
viscosity
kgf
(g/10 min)
TPU flow
154.6
156.5
155.2
beginning
temperature
(° C.)
Core yarn
Polyester
Polyester
Polyester yarn
yarn
yarn
TPU tensile
250 kgf/cm 2
230 kgf/cm 2
350 kgf/cm 2
strength
TPU tear
110 kgf/cm
105 kgf/cm
120 kgf/cm
strength
TPU specific
1.20-1.21
1.20-1.21
1.21-1.22
g/cc
gravity
TPU
91 ± 2A
91 ± 2A
92 ± 2A
Shore A
hardness
Minimum
0.2∅
0.2∅
0.4∅
PVC: 0.2∅
thickness of
coated yarn
Coated yarn
500-600
500-600
100-150
PVC: 600-
productivity
rpm/min
rpm/min
rpm/min
700 rpm/min
Adhesive
2.5-3.0
1.5-2.0
0.5-1.0
Adhered to
strength of
kgf
kgf
kgf
reflective film
mesh woven
(using glass
with coated
bead)
yarn
As can be seen from the results in Table 3 above, the products (“AK-92A-4” and “AK-92A-5”) obtained using silica as a thickener showed significantly high productivity, thin thickness and good adhesive strength compared to the product (“ESTANE58277(Lubrizol)”) obtained using general TPU. Also, it can be seen that the product “AK-92A-5” had low adhesive strength due to blooming caused by an excessively high content of silica. In addition, the use of silica can also provide matting effects.
Table 4 below shows the results of using an inorganic material (e.g., talc) as a thickener.
TABLE 4
TPU
Melt
Flow
Extru-
compound
index
beginning
sion
(product
(g/10
tempera-
Flow viscosity
work-
name)
min)
ture (° C.)
165° C.
170° C.
ability
Talc
ESTANE58277
19.58
155.2
30,950
10,830
Poor
0.0 phr
(Lubrizol)
TC-92A-3
9.50
157.8
43,380
15,030
Good
10 phr
TC-92A-6
5.65
158.5
60,550
18,880
Good
20 phr
As can be seen in Table 4 above, as the talc content increased, the melt index decreased and the flow viscosity increased, suggesting that talc showed a thickening effect. Also, it could be seen that the extrusion workability was good when the talc content was 10 phr or higher. Further, the product having a talc content of 30 phr showed good extrusion workability, but was difficult to apply, due to the occurrence of blooming.
Meanwhile, the product names “TC-92A-3” and “TC-92A-6” shown in Table 4 are TPU compounds for coating yarn, prepared by the composition and preparation method of the present invention. Preferably, these product names are TPU compounds for coating yarn, prepared using talc as a thickener. In addition, the product name “ESTANE58277 (Lubrizol)” shown in Table 4 is a compound for coating yarn, prepared according to the method of conventional technology.
Table 5 below shows components that are added to prepare TPU compounds (particularly “TC-92A-3” or “TC-92A-6” shown in Table 4) for coating yarn, and the composition ratio of the components.
TABLE 5
Composition of the
present invention
TC-92A-3 (wt %)
TC-92A-6 (wt %)
Footwear airbag scrap
40.0
40.0
Virgin TPU
44.5
34.5
Polyethylene-based
5.0
5.0
coupling agent
Talc (thickener)
10.0
20.0
Montane wax
0.2
0.2
Fatty acid ester
0.3
0.3
Table 6 below shows a composition between the physical properties of TPU compounds (particularly “TC-92A-3” and “TC-92A-6” shown in Table 5) for coating yarn, prepared by the composition and preparation method of the present invention, and the physical properties of a compound for coating yarn (e.g., “ESTANE58277 (Lubrizol) shown in Table 4), prepared by conventional technology.
TABLE 6
Compound
according to
conventional
TPU compounds of
technology
Product
the present invention
ESTANE58277
name
TC-92A-3
TC-92A-6
(Lubrizol)
Remarks
TPU melt
9.50
5.65
15.2
200° C., 2.16
viscosity
kgf
(g/10 min)
TPU flow
157.8
158.5
155.2
beginning
temperature
(° C.)
Core yarn
Polyester
Polyester
Polyester yarn
yarn
yarn
TPU tensile
200 kgf/cm 2
160 kgf/cm 2
350 kgf/cm 2
strength
TPU tear
100 kgf/cm
90 kgf/cm
120 kgf/cm
strength
TPU specific
1.21-1.22
1.22-1.23
1.21-1.22
g/cc
gravity
TPU
92 ± 2A
93 ± 2A
92 ± 2A
Shore A
hardness
Minimum
0.2∅
0.25∅
0.4∅
PVC: 0.2∅
thickness of
coated yarn
Coated yarn
300-400
300-400
100-150
PVC: 600-
productivity
rpm/min
rpm/min
rpm/min
700 rpm/min
Adhesive
1.5-2.0
1.0-1.5
0.5-1.0
Adhered to
strength of
kgf
kgf
kgf
reflective film
mesh woven
(using glass
with coated
bead)
yarn
As can be seen from the results in Table 6 above, the products (“TC-92A-3” and “TC-92A-6”) obtained using talc as a thickener showed high productivity and thin coated yarn thickness compared to the product (“ESTANE58277(Lubrizol)”) obtained using general TPU, but these products showed slightly low productivity and low adhesive strength compared to the products (“AK-92A-4” and “AK-92A-5”) obtained using silica as a thickener. Also, it can be seen that the product “TC-92A-6” had low adhesive strength due to blooming caused by an excessively high content of talc.
Table 7 below show the results of using polyacetal resin (POM) as a thickener when producing coated yarn using thermoplastic polyurethane according to the present invention.
TABLE 7
TPU
Melt
Flow
Extru-
compound
index
beginning
sion
(product
(g/10
tempera-
Flow viscosity
work-
POM
name)
min)
ture (° C.)
165° C.
170° C.
ability
content
ESTANE58277
19.58
155.2
30,950
10,830
Poor
0.0 phr
(Lubrizol)
PA-95A-3
10.20
178.2
52,240
27,830
Good
10 phr
PA-95A-5
6.65
185.1
63,580
37,880
Good
20 phr
As can be seen in Table 7 above, as the POM content increased, the melt index decreased and the flow viscosity increased, suggesting that POM showed a thickening effect. Also, it could be seen that the extrusion workability was good when the POM content was 10 phr or higher. Further, the product having a POM content of 10 phr showed good extrusion workability, but had hard significantly hard feeling due to increased hardness.
Additionally, the product names “PA-95A-3” and “PA-95A-5” shown in Table 7 are TPU compounds for coating yarn, prepared by the composition and preparation method of the present invention. Preferably, these product names are TPU compounds for coating yarn, prepared using polyacetal resin (POM) as a thickener. In addition, the product name “ESTANE58277 (Lubrizol)” shown in Table 7 is a compound for coating yarn, prepared according to the method of conventional technology.
Table 8 below shows components that are added to prepare TPU compounds (particularly “PA-95A-3” or “PA-95A-5” shown in Table 7) for coating yarn, and the composition ratio of the components.
TABLE 8
Composition of the
present invention
PA-95A-3 (wt %)
PA-95A-5 (wt %)
Virgin TPU
84.5
74.5
Polyethylene-based
10.0
20.0
coupling agent
POM resin
5.0
5.0
Montane wax
0.2
0.2
Fatty acid ester
0.3
0.3
Table 9 below shows a composition between the physical properties of TPU compounds (particularly “PA-95A-3” and “PA-95A-5” shown in Table 8) for coating yarn, prepared by the composition and preparation method of the present invention, and the physical properties of a compound for coating yarn (e.g., “ESTANE58277 (Lubrizol) shown in Table 7), prepared by conventional technology.
TABLE 9
Compound
according to
conventional
TPU compounds of the
technology
Product
present invention
ESTANE58277
name
AK-92A-3
AK-92A-5
(Lubrizol)
Remarks
TPU melt
10.2
6.65
15.2
200° C., 2.16
viscosity
kgf
(g/10 min)
TPU flow
178.2
185.1
155.2
beginning
temperature
(° C.)
Core yarn
Polyester
Polyester
Polyester yarn
yarn
yarn
TPU tensile
300 kgf/cm 2
250 kgf/cm 2
350 kgf/cm 2
strength
TPU tear
150 kgf/cm
160 kgf/cm
120 kgf/cm
strength
TPU specific
1.20-1.21
1.19-1.20
1.21-1.22
g/cc
gravity
TPU
95 ± 2A
97 ± 2A
92 ± 2A
Shore A
hardness
Minimum
0.2∅
0.2∅
0.4∅
PVC: 0.2∅
thickness of
coated yarn
Coated yarn
350-450
300-400
100-150
PVC: 600-
productivity
rpm/min
rpm/min
rpm/min
700 rpm/min
Adhesive
2.5-3.0
2.0-2.5
0.5-1.0
Adhered to
strength of
kgf
kgf
kgf
reflective film
mesh woven
(using glass
with coated
bead)
yarn
As can be seen from the results in Table 9 above, the products (“PA-95A-3” and “PA-95A-5”) obtained using POM resin as a thickener showed high productivity and thin coated yarn thickness compared to the product (“ESTANE58277(Lubrizol)”) obtained using general TPU, but these products showed slightly low productivity compared to the products obtained using silica. Also, it can be seen that the product “PA-95A-5” had high hardness due to an excessively high content of POM resin, suggesting that it would provide a fabric having significantly hard feeling.
From the results of using the thickeners as described above, it can be seen that the use of silica as a thickener showed the highest productivity and excellent matting effects, suggesting that it can provide the best product (coated yarn).
The physical properties shown in Tables 3, 6 and 9 above, including TPU melt viscosity, TPU flow beginning temperature, TPU tensile strength, TPU tear strength, TPU specific gravity and TPU hardness, are the physical properties of the TPU compound for coating yarn to be provided by the present invention.
2. Step of Producing Coated Yarn
The step of producing coated yarn is a step of coating the TPU compound on the surface of yarn (made of polyester, nylon, spandex or the like).
As shown in FIG. 2 , this step comprises: 1) mixing the TPU compound for coating yarn (i.e., pellet-type thermoplastic polyurethane as described above) with a master batch corresponding to a desired color and feeding the mixture into the hopper of a yarn coating extruder; 2) melting the mixture of the TPU compound and the master batch in the cylinder of the yarn coating extruder at a temperature of 150˜250° C. and a pressure of 50-150 kgf; 3) coating the TPU compound on the surface of yarn (made of polyester, nylon, spandex or the like) passing through a nipple and a dice to produce coated yarn; and 4) winding the coated yarn around a bobbin using a winding machine.
As shown in FIG. 2 , coated yarn comprising thermoplastic polyurethane according to the present invention can be obtained by coating a TPU compound (particularly, dried and aged pellet-type thermoplastic polyurethane), prepared by the preparation method and composition of the present invention, on the surface of yarn made of polyester, nylon, spandex or the like.
The thermoplastic polyurethane compound composition according to the embodiment of the present invention and the method of producing coated yarn using the thermoplastic polyurethane compound composition achieves the following effects.
First, because the thermoplastic polyurethane compound for coating yarn according to the present invention is prepared by compounding thermoplastic polyurethane with a thickener (preferably an inorganic material such as silica, talc or calcium carbonate) in an extruder, higher productivity (i.e., 3-5 times higher productivity) and excellent matting properties compared to the use of conventional thermoplastic polyurethane can be achieved in the present invention.
Second, fabric made of the coated yarn of the present invention has excellent abrasion resistance, high tensile strength and excellent waterproof properties and can show excellent thermal moldability and adhesive properties, compared to conventional fabric.
Third, because the coated yarn according to the present invention has excellent durability, abrasion resistance and mechanical strength, it can be applied to sports good, daily necessities, industrial supplies and the like.
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The present invention provides a coated yarn and a method for manufacturing a coated yarn having outstanding physical properties, the method comprising: collecting thermoplastic polyurethane in virgin form, or from scraps remaining after usage, for example, those used for airbag patterns in a shoe manufacturing process, or from scraps remaining after other thermoplastic polyurethane is processed; mixing the various kinds of thermoplastic polyurethane with various additives; compounding the resultant mixture using an extruder to prepare a thermoplastic polyurethane compound for a coated yarn; and coating the surface of a yarn made from polyester, nylon, spandex, etc. with the compound using an extruder.
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RELATION TO PRIOR APPLICATIONS
[0001] This nonprovisional application is based on prior provisional applications, U.S. Ser. No. 60/436,119 filed on Dec. 23, 2002, and U.S. Ser. No. 60/444,028 filed on Jan. 31, 2003.
BACKGROUND OF THE INVENTION
[0002] I. Field of the Invention
[0003] The present invention relates generally to devices and methods used to contain leaks of oil and other liquids having a specific gravity less than that of water from vessels or other fluid-containing structures below the surface of the ocean or any other body of water.
[0004] II. Background and Prior Art
[0005] It is well known that oil tankers, barges, and other oil-containing vessels occasionally sustain damage and release the contents of their cargo into the surrounding water. The cargo is typically oil, although other combustible fuels having a specific gravity less than water, such as gasoline, diesel, and kerosene, are often transported in this manner. Because the most common cargo is oil, however, that term will be used exclusively herein with the understanding that it is representative of all fluids having specific gravities less than 1.0. Such leaks sometimes occur when the vessel is still afloat, and in other cases, the vessel sinks to the bottom of the ocean and remains their permanently. In those instances when a vessel sinks, the oil may still be contained within the vessel, but may slowly leak out through the damaged hull or other opening. By virtue of its lower density, the oil will rise to the surface of the water. This accumulation of oil, sometimes referred to as an “oil slick”, is particularly difficult to collect, prompting tremendous efforts over the last several decades to devise equipment and methods to remove the oil from the surface.
[0006] Consequently, there is a great need for a system which can be employed to retrieve oil leaking from sunken vessels in a manner which prevents the oil from reaching the surface. Even if the oil-containing vessel is not leaking, the gradual effects of corrosion and ocean currents over the course of time will eventually cause the oil to escape from the vessel. Therefore, it is desirable to have an oil collection system which can also be positioned above a release hole formed into the penetrated hull of the vessel to remove the oil.
SUMMARY OF THE INVENTION
[0007] Therefore, one object of the present invention is to provide a subsea oil collector which collects oil from below the surface of the water.
[0008] It is also an object of the present invention to provide a subsea oil collector which can be positioned on the hull of a vessel at a select location.
[0009] A further object of the present invention is to provide a subsea oil collector which can be retrieved onto surface vessels or emptied in accordance with acceptable methods.
[0010] Another object of the present invention is to provide a subsea oil collector which can be guided into place by a remotely operated vehicle (ROV).
[0011] Accordingly, a subsea fluid collector is provided, comprising a container having a fluid inlet and a fluid outlet; a vessel positioning device operatively connected to the container; a closure mechanism to close the fluid inlet; and a closure mechanism to close the fluid outlet; wherein the container is positioned by the vessel positioning device to receive, through the fluid inlet, a leaking fluid (such as crude oil, gasoline, diesel, or the like) exiting from a fluid leak source on the vessel, and wherein water, if any, residing within the container is displaced as leaking fluid enters the container. Preferably, the vessel positioning device includes means for attaching to and detaching from the vessel, and is optionally controlled remotely. Also, it is preferable that both the inlet aclosure mechanism and outlet closure mechanism are controlled remotely, or by the volume of fluid collected within the container. In a preferred embodiment, the container has negative buoyancy prior to being filled with the leaked fluid.
[0012] In an alternate embodiment, the collector further includes a buoy residing at or near the surface of the water; and a guide cable having a first end operatively attached to the buoy, and a second end operatively attached at or near the fluid leak source; and wherein the container is slidably attached to the guide cable for ascent and descent. Optionally, a speed control means for controlling the speed at which the container slides along the cable is also present. In a further arrangement, the collector further inclues a fluid conduit operatively connected between the fluid outlet on the container and the buoy, wherein the conduit permits transfer of fluid from the container to the buoy.
[0013] In another alternate embodiment, the collector further includes a ballast chain and handling wire wherein the container is attached to ballast chain which is in turn attached to a lighter, high tensile, handling wire. The chain provides negative buoyancy to assist the container on its descent. Once the container reaches the ocean bottom, and the ballast chain lays on the ocean bottom, the container can be more easily maneuvered by an ROV with the assistance of the handling wire. The handling wire can be retrieved onto a reel type mechanism to assist the collector with a controlled ascent after it has been filled with fluids.
[0014] A method for collecting fluids below the sea is also disclosed, comprising the steps of providing a fluid collection container having a positioning mechanism, a fluid inlet, and a fluid outlet; mounting the container using the positioning device to a submerged vessel having a fluid leak source and positioning the fluid inlet above the leak source; permitting the leaking fluid to enter the container until the container is filled with fluid; closing the fluid inlet; and moving the container to the sea surface where it can be retrieved onto a surface vessel or the fluids can be transferred to a surface vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an elevation view of a preferred embodiment of the present invention, depicting the subsea oil collector in an operating configuration.
[0016] FIG. 2 is another view of the embodiment of FIG. 1 offloading the contents of the collector to a barge.
[0017] FIG. 3 is an elevation view of an alternative embodiment of the present invention depicting the subsea oil collector in an operating configuration, while offloading fluids into a barge at the ocean surface, and attached to a guide cable extending between a submerged vessel and a surface ship.
[0018] FIG. 4 is an elevation view of a third embodiment of the present invention depicting the subsea oil collector as including a ballast chain and handling wire device.
[0019] FIG. 5 is yet another embodiment employing features common to those in FIGS. 1-4 .
[0020] FIG. 6 is another view of the embodiment of FIG. 3 depicting the subsea oil collector in an operating configuration near the ocean bottom, while collecting fluids from the leaking source.
[0021] FIG. 7 is an elevation view of an alternative embodiment depicting the subsea oil collector attached to a guide cable extending between a submerged vessel and a buoy.
[0022] FIG. 8 is an elevation view of a basic alternative embodiment depicting the subsea oil colletor in an operating configuration without the attachment of any cables or wires.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Unless otherwise noted herein, all construction materials are fluid impervious, and all attachments between such components are structurally sound. Materials and methods are intended to impart a maximum level of strength and structural rigidity, while keeping the invention as lightweight and easy to use as possible. Certain features which are used in assembling or operating the invention, but which are known to those of ordinary skill in the art and not bearing upon points of novelty, such as screws, bolts, nuts, welds, and other common fasteners, may not be shown for clarity.
[0024] In preparation for use of the invention to be described below, a large release hole 11 is cut into one of the tanks on the submerged tanker or other vessel 10 using an ROV (in deep water) or by divers (at depths enabling diver operations). Immediately after the release hole 11 is formed, a closure mechanism is immediately installed on the vessel 10 , such as a magnetic cap, valve, or other suitable device capable of substantially sealing the release hole 11 , to prevent the premature release of fluids 12 through hole 11 .
[0025] Turning now to the figures, a preferred embodiment of a subsea oil collector 1 is illustrated in an elevation view in FIG. 1 . The collector 1 is shown in an operating configuration below the surface of the sea 6 , and includes a container 2 , which can be either a rigid structure or of flexible material, having a fluid inlet 3 and a fluid outlet 4 . The holding volume of the container 2 may be approximately 100,000 gallons, although this size may vary depending on the circumstances. The container 2 includes a positioning device 5 , which can simply be one or more link chains, cables or a mechanical latching device, which operates to position the container 2 above a vessel 10 which has a leak source 11 . Fluid 12 leaking from the leak source 11 is typically oil, gasoline or some other hydrocarbon-based fluid which has a positive buoyancy, e.g. a specific gravity less than that of the surrounding water. In the absence of the present invention, such fluid 12 would simply float to the surface 6 and form a “slick,” which is exceedingly difficult and expensive to contain and remove. Preferably, the collector 1 has a “negative” buoyancy upon entering the water, such that its weight and density will enable it to sink toward the vessel 10 relatively unassisted.
[0026] In the embodiment of FIG. 1 , the container 2 is suspended from a tethered cable 40 which is attached to the top of container 2 and originating from some other structure, typically a ship, barge, or other first surface vessel 41 , located on the sea surface 6 . Most conveniently, the cable 40 is attached to a cable storage reel 42 on the first surface vessel 41 , such that unwinding of the reel 42 permits the container 2 to sink toward the submerged vessel 10 , and winding of the reel 42 raises the container 2 for further handling.
[0027] With specific reference to the container 2 , inlet 3 may include a closure device or valve 7 which seals the container 2 at that location when closed, and which permits fluid 12 to enter container 2 when open. In typical applications, inlet 3 may range from 24 inches to 36 inches in diameter to accommodate the flow of fluids 12 released from hole 11 , although the specific size may vary depending upon the precise needs of the situation. Similarly, outlet 4 also includes a closure device or valve 8 which remains closed as the container 2 is filled with fluid 12 , but which can be opened to release the contents of the container 2 when it is retrieved. Both of closure devices 7 , 8 may be opened and closed manually by divers or by an ROV, depending upon the depth of the water. Alternatively, either or both of closure devices 7 , 8 can be opened or closed responsive to operating conditions or a fill condition of the container 2 . For example, inlet closure device 7 may be caused to close by a motor or other common solenoid device upon an electronic signal generated from buoyancy sensors indicating that the container 2 is becoming completely filled with fluid 12 .
[0028] Once the container 2 is positioned directly above the hole 11 or other leak source, the positioning device 5 is preferably attached to the vessel 10 . This task would be performed either by divers at the site or by an ROV depending on the depth. The outlet closure device 8 is closed to seal outlet 4 , and fluid 12 rises into the inlet 3 and displaces any water, if any, residing within the container 2 . As the volume of fluid 12 increases within the container 2 , water is continuously expelled through the inlet 3 until the container 2 is completely filled with fluid 12 . Since the density of the oil is less than the density of the water, the oil will float to the top of container 2 while displacing the water to the bottom of container 2 and then out through inlet 3 . When the container 2 is filled with fluid 12 , the inlet 3 is closed. Next, the positioning device 5 is detached from the vessel 10 in preparation for retrieval of the fluid-filled container 2 .
[0029] Preferably, the materials of construction of the container 2 and the positioning device 5 are such that the filled container 2 will ascend without assistance due to its increased buoyancy. If desired, additional flotation devices, such as buoyant materials commonly used for deep water marine applications, may also be installed onto the container 2 .
[0030] With respect to the attachment and detachment of the positioning device 5 , the positioning device 5 may also comprise mechanical devices or additional ropes or cables with anchors to ensure that the collector 1 is securely in place over the release hole 11 . Alternatively, the positioning device 5 may be detached in response to some other condition, such as by the closing of inlet closure device 7 or by reaching a predetermined volume of fluid 12 within container 2 . In either case, it is essential that the anchoring or attachment of the positioning device 5 be sufficiently secure to prevent the premature ascendence of the container 2 due to the increased buoyancy during collection of the fluid 12 .
[0031] Although not required, the container 2 may be constructed from a tightly woven scrim that is permeable by water but not by the leaking fluid, e.g. crude oil. In this configuration, water can simply be passed through the sides of the container 2 as fluid 12 fills the container 2 . Preferably, the top of the container 2 may be formed in the shape of an inverted cone, because the buoyancy forces applied to the top of the container 2 when filled will impart significant stresses to the fabricated container 2 . Constructing the top of the container 2 in this manner should serve to minimize such stress and avoid possible tearing.
[0032] FIG. 2 illustrates a preferred manner in which the contents of the collector 1 are offloaded. Upon closure of the inlet closure device 7 and release of the positioning devices 5 from the vessel 10 , a magnetic cover or other closure for the release hole 11 is reapplied as explained earlier. Since the container 2 is filled with oil, it should then naturally rise due to its positive buoyancy. As the container 2 approaches the surface 6 , an ROV or divers maneuver the container 2 toward the underside of a barge 43 or other containment vessel. The barge 43 includes an underside inlet 44 which is sized and shaped to interface with the outlet 4 of container 2 . Once the outlet 4 is connected to the barge inlet 44 , positioning devices 45 in the form of chains, cables, or other suitable means, are used to secure the container 2 to the barge 43 . Next, outlet closure device 8 is opened to allow the buoyant fluid 12 to enter the barge 43 . Generally, the buoyancy of the fluid 12 will be sufficient to convey the contents of container 2 directly into barge 43 , although assisted emptying of container 2 may be accomplished by pumps or vacuum methods known to those of ordinary skill in this field. Finally, when the container 2 is substantially empty, the outlet 4 is closed, and the positioning devices 45 are released, causing the empty collector 1 , due to its negative buoyancy, to sink back down toward the vessel 10 for another collection cycle. It should also be noted that although a second surface vessel in the form of barge 43 is described in this embodiment, it is also possible for the first surface vessel 41 to serve as the offloading location if it includes suitable storage compartments similar to those of barge 43 .
[0033] In FIGS. 3 and 6 , an alternative embodiment of the invention is shown, and further includes a barge 43 or other containment vessel residing at or near the surface 6 of the water and a guide cable 21 . The guide cable 21 includes a first end 22 operatively attached to the barge 43 , and a second end 23 operatively attached in close proximity to the fluid leak source, such as to a mechanical fastener which has been installed in or near the release hole 11 . Alternatively, the second end 23 can be attached to anchors adjacent to the release hole 11 . In this embodiment, the second end 23 of the guide cable 21 is attached either by divers or by an ROV depending upon the depth. The guide cable 21 serves as a guide for the container 2 , and is passed through a guide tube 24 extending within the center of the container 2 , thus making the container 2 slidably attached to the guide cable 21 . Optionally, the guide tube 24 may be attached to the outside of the container 2 with substantially the same effect. Also, while it is believed that a single guide cable 21 may be sufficient for most purposes, two or more such guide cables 21 may be employed to maintain the orientation of the container 2 . Thus, as container 2 is introduced into the water and descends toward the vessel 10 , it is guided and positioned above the release hole 11 with minimal assistance. Optionally, the collector 1 may include speed control means for controlling the speed at which the container 2 slides along the guide cable 21 during descent to the vessel 10 . For example, one such speed control means may comprise a friction-type lock which slows the rate of descent, but which also locks against the guide cable 21 once the container 2 reaches the vessel 10 . In this manner, the speed control device contributes to the secure placement of the container 2 and prevents its premature ascendance. Once the container 2 is properly in place, the positioning devices 5 are applied and the closure device or cover for the release hole 11 is opened by divers or by ROV, and the fluid 12 commences to fill the container 2 , as shown in FIG. 6 . When the container 2 is filled, the inlet 3 is closed as with the previous embodiment, and the closure device over the release hole 11 is replaced. Next, the locking mechanism is released by the divers or ROV, along with the positioning devices 5 , and the container 2 should rise due to its positive buoyancy. Offloading of the container 2 is essentially identical to the procedure described for the previous embodiment, except for the ease with which the container 2 may be guided toward the barge 43 by the guide cable 21 .
[0034] FIG. 4 illustrates a third embodiment of the present invention, depicting a variation on the first embodiment described above. Although the prior embodiments may be employed at a variety of depths, this embodiment is particularly suited to extreme depths, i.e. greater than about 5,000 feet. Specifically, the tethered cable 51 originates from a reel 42 similar to that described earlier, and it is attached at its opposite end 53 to the terminal end 54 of a ballast chain 55 or other suitably heavy and flexible device which can be used as will be explained below. Preferably, the cable 51 is constructed from a light, high tensile strength material whose weight at extreme depths will not significantly hinder the maneauverability of the container 2 , and which can be easily spooled and unspooled for frequent collection cycles over extended periods of time. In this embodiment, assuming that the ballast chain 55 is attached to the top of the container 2 , the ballast chain 55 is at least as long as the height and width of the container 2 , such that a portion of the ballast chain 55 may come to rest upon the surrounding surfaces. For example, as the container 2 comes into contact with the vessel 10 , the ballast chain 55 continues to sink and rest upon the surrounding surfaces or the ocean bottom. This effectively temporarily anchors the container 2 at the vessel 10 , but still permits the ROV to move the container 2 from side to side with much less power required than without the presence of the ballast chain 55 .
[0035] FIG. 5 is another embodiment which depicts an elongated container 2 slidably attached to a guide cable 21 , but which also includes a ballast chain 55 connected to a handling wire or cable 51 as described earlier. In this embodiment, the guide cable 21 would be attached between the vessel 10 and the offloading barge 43 , which the handling wire 51 originates from a reel 42 either on the same barge 43 or on another support vessel 41 . Note that in this embodiment, the ballast chain 55 is attached roughly midway along the container 2 , such that the only length requirement of the ballast chain 55 is that there be at least some portion of its length that will rest upon the surrounding surfaces when the container 2 is secured to the leaking vessel 10 .
[0036] FIG. 7 illustrates another embodiment of the invention in which the container 2 , as described previously herein with respect to FIGS. 3 and 6 , is slidably attached to a cable having a first end 22 attached to a buoy floating at or near the surface of the water. Optionally, the buoy may comprise a floating fluid vessel, and an additional conduit fluidically connected between the top of container 2 and the buoy or floating fluid vessel. In this manner, fluids collected within container 2 may rise through the conduit and into the floating fluid vessel, which can then be removed or emptied as described earlier herein.
[0037] Finally, FIG. 8 depicts the simplest embodiment in which the container 2 is maneuvered to its submerged position and retrieved for removal or emptying entirely by ROV or divers. Although both of these embodiments require the greatest amount of manual handling, their relatively inexpensive costs, in terms of both labor and equipment, may make them suitable for a variety of applications, such as in shallow water.
[0038] In all of the above described embodiments, an offloading pump on board surface vessels 43 may be used to connect to the outlet 4 to pump out fluids 12 within the container 2 . The fluids 12 may be pumped into towable bladders or into other barges on site. If necessary, a steam collar may be affixed to the outlet 4 to heat and facilitate offloading of highly viscous fluids 12 . Also, the filled container 2 may be towed to land for offloading or transported on a vessel to port for offloading at another site.
[0039] Although exemplary embodiments of the present invention have been shown and described, many changes, modifications, and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of the invention. For example, the invention could be adapted to capture oil that rises from naturally occurring oil seeps in the ocean floor, by modifying the mounting device as necessary to attach to sea floor structures.
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A subsea fluid collector is provided, comprising a container having a fluid inlet and a fluid outlet, and a vessel positioning device which is attachable to a submerged vessel leaking oil or other fluids. The container is positioned by the vessel positioning device to receive, through the fluid inlet, a leaking fluid (such as crude oil, gasoline, diesel, or the like) exiting from a fluid leak source on the vessel, and the water residing within the container is displaced as leaking fluid enters the container. The vessel positioning device may be attached or detached from the vessel by divers or remotely using a remotely operated vehicle (ROV). In one embodiment, the container may be guided into position above the leak by a guide cable. Once the container is filled by the leaking fluid, it ascends to the surface of the sea for retrieval and removal of the contents.
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FIELD OF THE INVENTION
[0001] The present invention relates to multi-ply platforms for the manufacture of floor and wall panels and floor and wall panels made using such multi-ply platforms.
BACKGROUND ART
[0002] Plywood is an example of a multi-ply product—that is a product which is made of a plurality of layers of sheet material in which the faces of adjacent sheets are bonded to each other. Plywood is a panel product manufactured by gluing together one or more veneers to both sides of a veneer, solid wood, or reconstituted wood core. In the case of solid-wood-core plywood and reconstituted-wood-core plywood, an additional intermediate step is the production of cores, which are made by lateral gluing of blocks or strips of wood or by gluing oriented wood chips with resin adhesives. Plywood has many advantages over natural wood, an important one being greater dimensional stability. Its uniformity of strength, resistance to splitting, panel form, and decorative value make it adaptable to various uses.
[0003] In plywood, both structural and decorative plywood, the grain of alternate layers is typically crossed, in general at right angles and the species, thickness, and grain direction of each layer are matched with those of their opposite number on the other side of the core or central veneer. The total number of layers of veneers is typically odd (three, five, or more) so that the physical properties of the plywood are balanced around its central plane (i.e. the plane parallel to the faces of the plywood and passing though the mid-line of the plywood) i.e. it has approximately the same physical properties (e.g. expansion/contraction with changes of temperature and/or humidity) on both sides of the midline. In other words, the potential for dimensional change when subject to changes of ambient temperature and/or humidity must be equal on the two sides of the panel at equal distances from the centre of the panel. Preferably in moving from the centre of a panel outward toward the surfaces, the panel makeup should be a mirror image on both sides of the panel. Balanced plywood is stable and less likely to cup, warp, shrink or swell. Laminating an odd number of plies [3, 5, 7 . . . ] reduces warping while increasing the number of plies increases the resistance to shearing forces.
[0004] Typically the grain direction of the two surface veneers (the front and back faces) is parallel to the longer dimension of rectangular sheets. Three-ply is stronger along the surface grain axis, but as the number of plies increase, the lengthwise/crosswise strengths and stiffness of a plywood sheet will become more equal. Three-ply bends easier along the grain direction of the surface plies because only the middle core ply will have crosswise grain. To ensure the strength and stiffness characteristics of three-ply in the face grain direction it is required that the thickness of each surface veneer is between 25% and 33% of the total sheet thickness, i.e. the two surface sheets comprise 50% to 66% of the total sheet thickness.
[0005] The outer plies may be called the ‘faces’ (or the ‘face’ and ‘back’) and the intermediate plies may be called the ‘crossbands’. In order to procure a balanced panel, with five or more plies the total thickness of the odd numbered plies [number 1 being a face ply] should be about the same total thickness as the even numbered plies.
[0006] Plywood is often used as a platform for decorative veneers or lamellae used in floor or wall panels. During the manufacture of such floor or wall panels (called “decorative panels” in the following for the sake of brevity, but without implying that the invention is restricted to panels having an attractive decorative veneer or lamella) a decorative veneer or a decorative solid wood sawn lamella, usually of a thickness of 2-4 mm in Europe but as little as 0.2 mm in Asia, of a decorative wood is attached, using by gluing, to one of the faces of a sheet of plywood. This leads to an unbalanced product as the formerly balanced plywood platform has the decorative veneer only attached to one face. When such decorative panels are subjected to changes in relative humidity, e.g. from 10% relative humidity during the winter months to 80-90% relative humidity during the summer, or large changes of temperature, deformations in the decorative surface may occur as the swelling and contraction of the fibres of the decorative veneer cannot be balanced by the underlying plywood platform.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide multi-ply platforms suitable for the manufacture of decorative panels, and decorative panels incorporating such multi-ply platforms, which multi-ply platforms improve the resistance to deformation caused by changes in relative humidity and/or temperature of, or around, such decorative panels.
[0008] The present invention achieves the above object by providing multi-ply platforms comprising a plurality of plies in which are arranged so that the platform is substantially unbalanced about its central plane. These unbalanced platforms are intended to be bonded to a further ply to form a substantially balanced decorative panel.
[0009] In one embodiment of the present invention this is achieved by providing a multi-ply platform in which a face ply and the adjacent underlying ply have substantially the same grain direction.
[0010] In a further embodiment of the present invention this is achieved by providing a multi-ply platform in which a face ply and the adjacent underlying ply and the next adjacent underlying ply have substantially the same grain direction.
[0011] In yet a further embodiment of the present invention this is achieved by providing a decorative panel comprising a decorative lamella attached to the face of a multi-ply platform wherein the grain direction of said face and at least the next adjacent ply are substantially the same and are substantially perpendicular to the grain direction of the decorative lamella. Further embodiments of the invention are also described in the following description.
DESCRIPTION OF THE FIGURES
[0012] FIG. 1 a ) shows schematically in perspective, an exploded view of the plies of a prior art 5-ply plywood sheet;
[0013] FIG. 1 b ) shows the sheet of FIG. 1 a ) in its assembled state;
[0014] FIG. 1 c ) is an end view of the platform of FIG. 1 b ) seen from the direction of arrow c in FIG. 1 b );
[0015] FIG. 2 a ) shows schematically in perspective, an exploded view of an example of the veneer and plies of a prior art decorated plywood panel;
[0016] FIG. 2 b ) shows the decorated plywood panel of FIG. 2 a ) in its assembled state;
[0017] FIG. 2 c ) is an end view of the panel of FIG. 2 b ) seen from the direction of arrow c in FIG. 2 b );
[0018] FIG. 3 a ) shows schematically in perspective, an exploded view of the plies of a 4-ply multi-ply platform in accordance with a first embodiment of the present invention;
[0019] FIG. 3 b ) shows the multi-ply platform of FIG. 3 a ) in its assembled state;
[0020] FIG. 3 c ) is an end view of the platform of FIG. 3 b ) seen from the direction of arrow c in FIG. 3 b );
[0021] FIG. 4 a ) shows schematically in perspective, an exploded view of an example of the veneer and plies of a decorated panel using a multi-ply platform in accordance with the first embodiment of the present invention;
[0022] FIG. 4 b ) shows the decorated panel of FIG. 4 a ) in its assembled state;
[0023] FIG. 4 c ) is an end view of the panel of FIG. 4 b ) seen from the direction of arrow c in FIG. 4 b );
[0024] FIG. 5 a ) shows schematically an end view of a second embodiment of a multi-ply platform in accordance with the present invention;
[0025] FIG. 5 b ) shows schematically an end view of a decorated panel using a multi-ply platform in accordance with the second embodiment of the present invention;
[0026] FIGS. 5 c ) to 5 h ) shows schematically end views of multi-ply platforms in accordance with the further embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] In the following it is assumed merely for the sake of brevity that multi-ply platforms and decorated panels in accordance with the present invention have a rectangular shape of defined length, width and thickness wherein the thickness is less than the length and width, however the present invention is applicable to panels and platforms of any shape. Furthermore the term multi-ply is not intended to be limited to panels and platforms consisting only of wooden plies, but is intended to encompass any multi-ply constructions in which one or more plies are made of a material which has properties in one direction which are different to the properties in the same ply in a substantially orthogonal direction, one of these directions being defined the grain (or longitudinal) direction, the other being defined the cross direction, and/or one or more plies is made of medium density fibreboard (MDF), high density fibreboard (HDF), woven material, non-woven materials, paper, impregnated paper, metal (e.g. aluminium), foil, plastics, polymer material, composite materials, rubber and/or any other material which can provide a desired characteristic (for example, one of more of the following non-exhaustive list of desirable characteristics: improved strength, improved flexibility, reduced flexibility, improved water-resistance, improved machineability, local reinforcement at high-stress regions (e.g. where panels are intended to provided with mutually cooperating features which allow panels to be joined together), reduced sensitivity to moisture, better sound-damping) to the panel or platform—these plies can be solid or perforated and optionally provided with features such as ribs, grooves, projections and depressions to give desired mechanical properties and/or to improve bonding between plies. The following terminology will be used: the longest dimension of the platforms and panels extends in the longitudinal direction, and plies, veneers or the like having their grain in the longitudinal direction will be called longitudinal grain panels. The direction transverse to the longitudinal direction (i.e. the direction in the plane of a ply at 90° to the longitudinal direction) is the cross direction and plies, veneers or the like having their grain in the cross direction will be called cross grain plies. Plies having no discernable grain (e.g. MDF plies) will be called neutral plies. While neutral plies have no discernable grain it is possible that to make plies which have different properties in the longitudinal and cross directions, for example by selecting the orientation of fibres in composite materials or by adding strengthening ribs or the like to panels and in such panels if the axis with the greatest resistance to bending is the longitudinal axis then such panels will be considered to be equivalent to longitudinal grain panels. Similarly if the axis with the greatest resistance to bending is the transverse axis then such panels will be considered to be equivalent to cross grain panels. The direction perpendicular to the plane of a ply is called the thickness. Thus in platform or panel having dimensions of 2400 mm×1200 mm×15 mm, the longitudinal direction extends for 2400 mm, the transverse direction extends for 1200 mm and the platform or panel is 15 mm thick. Grain direction is illustrated by thick, double-ended arrows in the figures.
[0028] FIG. 1 a ) shows an exploded view of a prior art 5-ply plywood sheet 1 . Sheet 1 comprises 5 veneers, 3 , 5 , 7 , 9 , 11 arranged in a pile with their edges aligned. Veneers 3 and 5 are face plies—i.e. they have a face surface that is exposed and each has its grain substantially aligned in the longitudinal direction of the sheet 1 —a ply or veneer with its grain substantially aligned in the longitudinal direction will henceforth will be called a longitudinal grain ply (or “L”). The middle ply 9 is also a longitudinal grain ply. Positioned adjacent to both sides of the middle ply 9 are intermediate plies 7 , 11 . These plies each have their grain in the cross direction and a ply or veneer with its grain substantially aligned in the cross direction will henceforth will be called a cross grain ply (“C”)
[0029] FIGS. 1 b ) and 1 c ) show the plies of FIG. 1 a ) assembled into a plywood sheet—not shown is the adhesive applied between contacting faces in order to hold the plies together. This has 5 plies arranged L-C-L-C-L. This is a balanced plywood sheet as the number of plies and the directions of their grains are symmetrical about the central plane of the sheet.
[0030] FIG. 2 a ) shows an exploded view of a prior art decorated plywood panel 13 . Decorated plywood panel 13 comprises a plywood panel covered by a decorative lamella 15 . Depending on the type of decorated plywood panel being made lamella 15 can be a peeled, sliced or sawn sheet of material, usually wood if the decorated plywood panel is to be used for walls or flooring. The grain direction of the material of lamella 15 is in the longitudinal direction so it is a longitudinal grain ply.
[0031] FIGS. 2 b ) and 2 c ) show the lamella and plywood sheet of FIG. 2 a ) assembled into a decorated plywood panel 13 —not shown is the adhesive applied between contacting faces in order to hold the lamella (“La”) and plywood sheet together. This has panel has 6 plies arranged La-L-C-L-C-L. This is an unbalanced panel as the number of plies and the directions of their grains are asymmetrical about the central plane of the sheet. This means that when such a panel is subject to changes in humidity and/or temperature there is a high probability that the panel will deform in an asymmetric manner.
[0032] FIG. 3 a ) shows schematically in perspective an exploded view of the plies of a 4-ply multi-ply platform 21 in accordance with a first embodiment of the present invention. Platform 21 is intended to be joined with a decorative lamella which has its grain direction in the longitudinal direction in order to form a decorated panel, e.g. for use as a wall or floor. Platform 21 comprises 4 veneers 23 , 25 , 27 , 29 arranged in a pile with their edges aligned. Contrary to the construction normally used in prior art plywood sheets, the veneers are not arranged with alternating grain directions. Veneer 23 is a face ply and has a visible working surface 31 which is intended to receive a decorative lamella when the platform is made into a decorated panel. Veneer 23 has a grain direction which is substantially perpendicular to the grain direction of the decorative lamella which is intended to be attached to it. Veneer 25 is also a face ply and it has a grain direction which is parallel with the grain direction of the decorative lamella which is intended to be attached to veneer 23 . There are two intermediate plies 27 , 29 each of which have their grain directions aligned with that of veneer 23 . In this example as the multi-ply platform is intended to be used with a wooden decorative lamella (also called “top wear layer”) which has its grain direction in the longitudinal direction veneers 23 , 27 and 29 are cross grain ply and face veneer 25 is longitudinal grain ply.
[0033] FIGS. 3 b ) and 3 c ) show the plies of FIG. 3 a ) assembled into a multi-ply platform—not shown is the adhesive applied between contacting faces in order to hold the plies together. This platform 21 has four plies 23 , 27 , 29 , 25 arranged C-C-C-L. This is unbalanced as the number of plies and the directions of their grains are asymmetrical about the central plane of the sheet.
[0034] FIG. 4 a ) shows an exploded view of a first embodiment of a decorated multi-ply panel 33 in accordance with the present invention. Decorated multi-ply panel 33 comprises the multi-ply platform 21 covered by a decorative lamella 35 . Depending on the type of decorated multi-ply panel being made lamella 35 can be a peeled, sliced or sawn sheet of material, usually wood if the decorated multi-ply panel 33 is to be used for walls or flooring. In order to form a balanced panel the grain direction of the material of the lamella 35 is in the longitudinal direction so it is a longitudinal grain ply.
[0035] FIGS. 4 b ) and 4 c ) shows the lamella 35 and multi-ply platform 21 of FIG. 4 a ) assembled into a decorated multi-ply panel 33 —not shown is the adhesive applied between contacting faces in order to hold the lamella 35 and multi-ply platform 21 together. This has panel has 5 plies arranged Lamella-C-C-C-L. Preferably the properties of the lamella and plies are matched in strength and density. They may also be matched in thickness. If lamella and all the plies are made of the same material then preferably the lamella 35 and the bottom face ply 25 have the same thickness and the total thickness of lamella 35 and face ply 25 is substantially the same as the total thickness of plies 23 , 27 and 29 . This will give a balanced panel as the number of plies and the directions of their grains are symmetrical about the central plane of the sheet. In general it is desirable that in a substantially balanced panel using the same type of material for each ply that the combined thickness of longitudinal grain plies is substantially the same as the combined thickness of cross grain plies, however if different types of material are used, e.g dense wood for longitudinal grain plies and less dense wood for cross grain plies then the total thickness of the cross grain plies may need to be thicker than the total thickness of the longitudinal grain plies in order to achieve a balanced panel.
[0036] If the grain direction of the material of the lamella is in the cross direction, i.e. it is a cross ply, then in order to achieve a balanced decorated multi-ply panel, the lamella should be attached to a multi-ply platform with a ply structure L-L-L-C, the lamella La being attached to the outermost L ply to form a multi-ply panel with plies arranged La-L-L-L-C.
[0037] In a second embodiment of the present invention, an unbalanced multi-ply platform comprises three plies. In the event that the multi-ply platform is intended to be used with a lamella in which the grain direction of the material of the lamella is in the longitudinal direction then the multi-ply platform would have a ply structure C-C-L, the lamella being attached to the outermost C ply to form a multi-ply panel with plies arranged Lamella-C-C-L. Conversely, in the event that the multi-ply platform is intended to be used with a lamella in which the grain direction of the material of the lamella has is in the cross direction then the multi-ply platform would have a ply structure L-L-C, the lamella being attached to the outermost L ply to form a multi-ply panel with plies arranged La-L-L-C.
[0038] Other embodiments of unbalanced platforms in accordance with the present invention are also conceivable where more that 3 consecutive plies have substantially the same grain direction, for example C-C-C-C . . . or L-L-L-L . . . , are then followed by one or more plies, at least the first of which has a substantially perpendicular grain direction, i.e. C-C-C-C-L . . . or L-L-L-L-C . . . as shown in FIGS. 5 c ) and 5 d ).
[0039] Further embodiments of unbalanced platforms in accordance with the present invention are conceivable in which one or more neutral plies are present. If only one neutral layer is provided then it is may be provided in a position such that when the platform is made into a decorative panel by adding a decorative lamella the central plane of the panel will lie in the neutral ply—for example if the neutral ply is made of some strong but flexible material, such metal or MDF or HDF or composite material or the like, and is intended to form part of a locking system for holding laid panels together. As one alternative the neutral ply can be the ply furthest away from the decorative lamella (for example if the neutral ply is waterproof and is intended to stop water under the platform from penetrating into the platform) as shown in FIG. 5 e ) or as another alternative it can form the ply directly in contact with the lamella (for example if the neutral ply is waterproof and is intended to stop water on the panel from penetrating into the platform) as shown in FIG. 5 f.
[0040] An embodiment of a platform comprising a neutral ply could, for example, have the plies arranged L-L-L-N-C as shown in FIG. 5 g ) (with optional additional N and L shown in dotted lines) and a decorative panel based on this platform could have the plies arranged Lamella-L-L-L-N-C. In this case the lamella would be a cross grain ply. Purely as an example a further embodiment of a platform comprising a neutral ply could have plies arranged L-L-N-L-C as shown in FIG. 5 h ) and a decorative panel based on this platform could have the plies arranged Lamella-L-L-N-L-C. In this case the lamella would be a cross grain ply. Other unbalanced platform arrangements (such as C-N-C-L, C-C-N-C-C-L, etc) are also conceivable and in these examples a substantially balanced decorative panel would have a lamella which has the characteristics of a longitudinal grain ply.
[0041] If a neutral ply is thin and flexible, for example, a plastic film intended to act as a vapour or moisture barrier, and therefore doesn't significantly affect the strength of the platform then it can be placed anywhere in the platform without substantially affecting the balance of the final decorative panel.
[0042] More than one neutral layer can be incorporated into a platform (as shown by dotted lines in FIGS. 5 g ) and 5 h )—for example a water-proof plastic film could be provided to reduce the penetration of water into the platform while a MDF, HDF, plastic, polymer, composite material, and a metal ply could be provided to provide local strength and/or flexibility and/or improved machineability—for example if a simple tongue and groove joining system 51 , 53 (as shown schematically in 5 g ) or more complicated projection and groove click-lock or snap-lock 55 , 57 (as shown schematically in FIG. 5 h ) joining system formed in the edges of the platform is to be used. Such joining systems comprise a projection in one edge of the platform and a corresponding groove in the opposite edge of the platform, the groove being able to receive the projection from an adjacent panel (when the platforms have been made into panels and are being laid together). Possible joining systems are not limited to the examples shown in FIGS. 5 g ) and 5 h ) but can be of any type. They may be formed in, extend through or comprise more than one ply and are not limited to being formed in neutral plies. Furthermore joining systems are conceivable which use additional components intended to be fitted between adjacent panels during laying (or hanging) of the panels, for example aluminium profiles which are fitted into grooves in the panels, said grooves being adapted to receive and grip the profiles.
[0043] An advantage of platforms and multi-ply panels incorporating such platforms in accordance with the present invention is that as the multi-ply panel is balanced, it can be made thinner than a conventional panel intended for the same use. For example, if a conventional floor panel is intended to use a 2 mm thick lamella as the wear surface then in order to achieve good dimensional stability during use, the 2 mm thick lamella is commonly attached to a 10 mm thick 5-ply balanced plywood platform. However, in accordance with the present invention, the same dimensional stability can be achieved by using an unbalanced platform which is only 6 mm thick after sanding. This platform can be made of three 2.1 mm thick plies glued together in C-C-L order. The platform can be sanded which removes 0.15 mm from the face plies resulting in an unbalanced platform which is 6 mm thick with the total thickness of the C-plies totalling 4.05 mm and the L ply being 1.95 mm thick. When a 2 mm lamella is glued to the working surface of the outermost C-ply the result will be an 8 mm thick panel which has Lamella-C-C-L ply arrangement and in which the total thickness of Lamella and L-plies is 3.95 mm and the total thickness of the C-plies is 4.05 mm. This is substantially balanced (the ratio of C-plies to L-plies is almost 1:1) and uses only about ⅔ of the material required for the conventional product.
[0044] Furthermore, it is conceivable that in a platform in accordance with the present invention a plurality of consecutive plies with substantially the same grain direction are followed by a plurality of consecutive plies with a substantially perpendicular grain direction e.g. C-C-C-L-L. For example, if a panel is intended to use a 4 mm thick lamella with longitudinal grain then it conceivable that it could be attached to a platform in accordance with the present invention which platform has 5 plies, each nominally 2 mm thick and arranged C-C-C-L-L thereby forming a panel Lamella-C-C-C-L-L. Using ply thicknesses of 4-2.7-2.7-2.7-2-2 mm would give a substantially balanced panel.
[0045] In order to make a substantially balanced 20 mm thick multi-ply panel using a 5 mm lamella with grain in the longitudinal direction, an unbalanced platform in accordance with the present invention could be made of five plies arranged C-C-C-L-L. The C-plies can be 3.4 mm thick and the L-plies can be 2.6 mm thick, for a total thickness of 15.4 mm. This platform is unbalanced to the extent that it needs one or more additional plies added onto the exposed C-ply which additional plies are the equivalent of the two longitudinal plies to balance it. After sanding 0.2 mm from each face, the total thickness would be 15 mm of which 10 mm is C-ply and 5 mm L-ply. When the 5 mm thick lamella is glued to the working surface of the outermost C-ply the result is a 20 mm thick substantially balanced panel which has Lamella-C-C-C-L-L ply arrangement and in which the total thickness of Lamella and L-plies is 10 mm and the total thickness of the C-plies is 10 mm.
[0046] Alternatively a substantially balanced 20 mm thick multi-ply panel using a 5 mm lamella with grain in the longitudinal direction, can be made using an unbalanced platform with 6 plies arranged C-C-C-C-L-L. This platform is unbalanced to the extent that it needs one or more additional plies added onto the exposed C-ply which additional plies are the equivalent of the two longitudinal plies to balance it. The C-plies can be 2.5 mm thick and the L-plies can be 2.6 mm thick for a total of 15.2 mm. After sanding 0.1 mm from each face, the total thickness would be 15 mm of which 9.9 mm is C-ply and 5.1 mm L-ply. When the 5 mm thick lamella is glued to the working surface of the outermost C-ply the result is a 20 mm thick substantially balanced panel which has Lamella-C-C-C-C-L-L ply arrangement and in which the total thickness of Lamella and L-plies is 10.1 mm and the total thickness of the C-plies is 9.9 mm.
[0047] All platforms and panels in accordance with the present invention may be adapted to have one or more of their edges profiled to enable panels and platforms laid adjacent each other to be fastened together by mutually cooperating features such as click-lock, snap-lock or tongue and groove projections and depressions.
[0048] The present invention is not limited to the embodiments described and modifications can be made to them without departing from the scope of the invention as set forth in the appended claims.
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A multi-ply platform suitable for the manufacture of decorative panels and decorative panels incorporating such multi-ply platforms, which has improved resistance to deformation caused by changes in relative humidity and/or temperature of, or around, such decorative panels. This multi-ply platform includes a plurality of plies which are arranged so that the platform is substantially unbalanced around its central plane. The unbalanced platform is achieved by, arranging the plies such that at least two adjacent plies have substantially the same main grain direction and/or that two plies having substantially the same main grain direction are separated only by one or more neutral plies. These unbalanced platforms are intended to be bonded to a further ply to form a substantially balanced decorative panel.
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BACKGROUND
[0001] This disclosure relates to a system and method for treating a subterranean formation surrounding a wellbore, and, more particularly, to such a system and method for removing downhole tools that are inserted into the wellbore to perform various operations in connection with recovering hydrocarbons from the formation.
[0002] Various types of downhole tools are inserted into a well in connection with producing hydrocarbons from the formation surrounding the well. For example, tools for plugging, or sealing, different zones of the formation are often inserted in the wellbore to isolate particular zones in the formation. After the operation is complete, the plugging or sealing tools must be removed from the wellbore which can be accomplished by inserting a drilling tool, mud motor, or the like into the wellbore and mechanically breaking up the tools by drilling, milling, or the like. However this removal process requires multiple trips in and out of the hole, is expensive, and time consuming.
[0003] The present invention is directed to a system and method for removing tools from a wellbore that is an improvement over the above techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] [0004]FIG. 1 is a partial elevational/partial sectional view, not necessarily to scale, depicting a well and a system for recovering oil and gas from an underground formation.
[0005] [0005]FIG. 2 is a sectional view of an example of a tool that is inserted in the well of FIG. 1 then removed according to an embodiment of the present invention.
[0006] [0006]FIGS. 3-5 are enlarged sectional views of the well of FIG. 1 illustrating several steps of inserting and removing the tool of FIG. 2 according to the above embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] Referring to FIG. 1, the reference numeral 10 refers to a wellbore penetrating a subterranean formation F for the purpose of recovering hydrocarbons from the formation. To this end, and for the purpose of carrying out a specific operation to be described, a downhole tool 12 is lowered into the wellbore 10 to a predetermined depth, by a string 14 , in the form of wireline, coiled tubing, jointed tubing, or the like, which is connected to the upper end of the tool 12 . The tool 12 is shown generally in FIG. 1 but will be described in detail later. The string 14 extends from a rig 16 that is located above ground and extends over the wellbore 10 . The rig 16 is conventional and, as such, includes support structure, a motor driven winch, and other associated equipment for receiving and supporting the tool 12 and lowering it into the wellbore 10 by unwinding the string 14 from a reel, or the like, provided on the rig 16 .
[0008] At least a portion of the wellbore 10 can be lined with a casing 20 , and the casing 20 is cemented in the wellbore 10 by introducing cement 22 in an annulus formed between the inner surface of the wellbore 10 and the outer surface of the casing 20 , all in a convention manner. A production tubing 26 having a diameter greater than that of the tool 12 , but less than that of the casing 20 , is installed in the wellbore 10 in a conventional manner and extends from the ground surface to a predetermined depth in the casing 20 .
[0009] For the purpose of example only, it will be assumed that the tool 12 is in the form of a plug that is used in a stimulation/fracturing operation to be described. To this end, and with reference to FIG. 2, the tool 12 includes an elongated tubular body member 32 having a continuous axial bore extending through its length for passing fluids in a manner to be described. A cage 34 is formed at the upper end of the body member 32 for receiving a ball valve 36 which prevents fluid flow downwardly through the body member 32 , as viewed in FIG. 1, but permits fluid flow upwardly through the body member 32 .
[0010] A packer 40 extends around the body member 32 and can be formed by a plurality of angularly spaced sealing elements. A plurality of angularly spaced slips 42 are mounted around the body member 32 just below the packer 40 . A tapered shoe 44 is provided at the lower end of the body member 32 for the purpose of guiding and protecting the tool 12 as it is lowered into the wellbore 10 . An explosive device 46 is mounted on the body member 32 . The explosive device 46 can be in the form of any type of conventional explosive sheet, detonation cord, or the like.
[0011] With the exception of the ball valve 36 and any elastomers or other sealing elements utilized in the packer 40 , all of the above components, as well as many other components making up the tool 12 which are not shown and described above, are fabricated from cast iron, i.e. a hard, brittle, nonmalleable iron-carbon alloy. As a non-limiting example, the cast iron can be an iron-carbon alloy containing 2 to 4.5 percent carbon, 0.5 to 3 percent silicon, and lesser amounts of sulfur, manganese, and phosphorus. The cast iron is relatively high in strength yet fractures, shatters, or otherwise breaks up under detonation exposure due to its brittle nature, for reasons to be described. Otherwise, the tool 12 is conventional and therefore will not be described in further detail.
[0012] [0012]FIGS. 3-5 depict the application of the tool 12 in an operation for recovering hydrocarbons from the formation F. In particular, and referring to FIG. 3, a lower producing zone A, an intermediate producing zone B, and an upper producing zone C, are all formed in the formation F. A plurality of perforations 20 a and 22 a are initially made in the casing 20 and the cement 22 , respectively, adjacent the zone A. This can be done in a conventional manner, such as by lowering a perforating tool (not shown) into the wellbore 10 , performing the perforating operation, and then pulling the tool from the wellbore 10 .
[0013] The area of the formation F adjacent the perforations 20 a and 22 a can then be treated by introducing a conventional stimulation/fracturing fluid into the wellbore 10 , so that it passes through the perforations 20 a and 22 a and into the formation F. This stimulation/fracturing fluid can be introduced into the wellbore 10 in any conventional manner, such as by lowering a tool containing discharge nozzles or jets for discharging the fluid at a relatively high pressure, or by passing the stimulation/fracturing fluid from the rig 16 directly into the wellbore 10 . In either case, the stimulation/fracturing fluid passes through the perforations 20 a and 22 a and into the zone A for stimulating the recovery of production fluids, in the form of oil and/or gas containing hydrocarbons. The production fluids pass from the zone A, through the perforations 20 a and 22 a, and up the wellbore 10 to the production tubing 26 for recovery at the rig 16 . If the stimulation/fracturing fluid is discharged through a downhole tool as described above, the latter tool is then removed from the wellbore 10 .
[0014] The tool 12 is then lowered by the string 14 into the wellbore 10 to a position where its lower end portion formed by the shoe 44 is just above the perforations 20 a and 22 a, as shown in FIG. 4. The packer 40 is set to seal the interface between the tool 12 and the casing 20 and thus isolate the zone A. The string 14 is disconnected from the tool 12 and returned to the rig 16 . The production fluids from the zone A then pass through the perforations 20 a and 22 a, into the wellbore 10 , and through the aforementioned bore in the body member 32 of the tool 12 , before flowing up the wellbore 10 to the production tubing 26 for recovery at the rig 16 .
[0015] A second set of perforations 20 b and 22 b are then formed, in the manner discussed above, through the casing 20 and the cement 22 , respectively, adjacent the zone B just above the upper end of the tool 12 . The zone B can then be treated by the stimulation/fracturing fluid, in the manner discussed above, causing the recovered fluids from the zone B to pass through the perforations 20 b and 22 b and into the wellbore 10 where they mix with the recovered fluids from the zone A before flowing up the wellbore 10 to the production tubing 26 for recovery at the ground surface.
[0016] As shown in FIG. 5, another tool 12 ′ is provided, which is identical to the tool 12 and thus includes identical components as the tool 12 , which components are given the same reference numerals. The tool 12 ′ is lowered by the string 14 into the wellbore 10 to a position where its lower end portion formed by the shoe 44 is just above the perforations 20 b and 22 b. The packer 40 of the tool 12 ′ is set to seal the interface between the tool 12 ′ and the casing 20 and thus isolate the zone B. The string 14 is then disconnected from the tool 12 ′ and returned to the rig 16 .
[0017] A third set of perforations 20 c and 22 c are then formed in the casing 20 and the cement 22 adjacent the zone C and just above the upper end of the tool 12 ′, in the manner discussed above. The zone C can then be treated by the stimulation/fracturing fluid, also in the manner discussed above, causing the recovered fluids from the zone C to pass through the perforations 20 c and 22 c and into the wellbore 10 where they mix with the recovered fluids from the zones A and B before passing up the wellbore 10 to the production tubing 26 for recovery at the ground surface.
[0018] It can be appreciated that additional producing zones, similar to the zones A, B, and C, can be provided above the zone C, in which case the above operations would also be applied to these additional zones.
[0019] After the above fluid recovery operations are terminated, the tools remaining in the wellbore 10 , which in the above example are tools 12 and 12 ′, must be removed from the wellbore 10 . In this context, and as stated above, many of the components making up the tools 12 and 12 ′ are fabricated from cast iron. Therefore upon detonation of the explosive device 46 , the cast iron components of the tools 12 and 12 ′ fracture, shatter, or otherwise break up into many relatively small pieces which will fall to the bottom of the wellbore 10 . The above detonation of the explosive device 46 can be initiated by a timer (not shown) built into the tools 12 and 12 ′, and the detonations can either be simultaneously or sequentially.
[0020] According to an alternate embodiment, many of the above components making up the tools 12 and 12 ′, with the exception of the ball valve 36 and any elastomers or other sealing elements utilized in the tools 12 and 12 ′, are fabricated from any conventional ceramic material which, in general, can consist of any of various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing a nonmetallic mineral, such as clay, at a high temperature. The ceramic material offers relatively high strength and high chemical resistance, yet fractures, shatters, or otherwise breaks up relatively easily under detonation exposure due to its brittle nature.
[0021] Thus, upon detonation of the explosive device 46 , the ceramic components of the tools 12 and 12 ′ will fracture, shatter, or otherwise break up into many relatively small pieces which will fall to the bottom of the wellbore 10 . As in the previous embodiment, the above detonation of the explosive device 46 can be initiated by a timer (not shown) built into the tools 12 and 12 ′ and the detonations can either be simultaneously or sequentially. Therefore this alternative embodiment enjoys all of the advantages of the first embodiment.
[0022] Thus, according to each of the above embodiments, the downhole tool(s) 12 and 12 ′ can be easily and quickly removed with a minimum of time and expense.
Variations and Alternates
[0023] (1) The type of downhole tools, or portions of downhole tools, utilized and fractured, shattered, or otherwise broken up the above manner can be varied.
[0024] (2) The entire portion of the downhole tools 12 and 12 ′ can be fabricated from cast iron or ceramic.
[0025] (3) The explosive device 46 on the downhole tools 12 and 12 ′ can be detonated in any know manner other than by a timer.
[0026] (4) The number of downhole tools broken up in the above manner can vary.
[0027] (5) The casing 20 , and therefore the cement 22 , can be eliminated.
[0028] (6) The type of material forming the downhole tools 12 and 12 ′, or the components of the tools discussed above, can vary as long as the material fractures, shatters, or otherwise breaks up upon detonation of the explosive device 46 .
[0029] (7) The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many other modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
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A method of treating a subterranean formation surrounding a wellbore, according to which a tool inserted into the wellbore for performing a function in the wellbore is fabricated of a material that breaks up upon detonation of an explosive mounted on the tool, thus allowing the pieces of the tool to fall to the bottom of the wellbore.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention pertains to a vehicle employed in the rehabilitation of water wells. Specifically, the present invention pertains to a vehicle mounting a 3,000 gallon-capacity tank and a 135 horsepower hydraulic pump connected in fluid communication with the tank through a network of fluid conducting conduits that together provide an apparatus that transports all of the necessary equipment to a water well location for rehabilitation of the well.
(2) Description of the Related Art
Water wells are formed by drilling the well downward through the ground to a certain depth where the well intersects one or more aquifers or water bearing stratum of permeable rock, sand, or gravel. Water in the aquifer(s) flows through the permeable rock, sand, or gravel and fills the drilled well to a certain depth. As water is pumped from the well, water continues to flow through the spaces between the permeable rock, sand, or gravel back into the well. A well's efficiency is rated by its specific capacity (SC) which is defined as the ratio of gallons per minute of water being pumped from the well divided by the number of feet of draw down or the number of feet the water level decreases in the well.
A new well constructed properly should have an efficiency approaching 100%. However, after a well has been used over a period of time, the spaces between the permeable rock, sand, or gravel in the aquifer(s) intersected by the well will often become blocked with dissolved minerals in the ground water traveling through the aquifer(s) or blocked biologically, for example by iron bacteria that feed on amounts of iron carried in the ground water. The blockage of the spaces between the rock, sand, or gravel creates an increased resistance to the flow of water through the aquifer(s) to the well and results in a lower pumping level of the water in the well and subsequently, a lower specific capacity (SC) of the well. Should the situation go unremedied and allowed to continue without well cleaning being performed, the specific capacity of the well could be reduced to the point that the well would no longer be useful requiring a new well to be drilled.
Water wells require periodic maintenance and cleaning to maintain their specific capacities. Well rehabilitation is the art of thoroughly cleaning mineral and biological deposits from the well to increase the specific capacity of a deteriorated well.
In the prior art, mechanical well cleaning methods and acid injections have been used to rehabilitate water wells. However, in many situations these have proven to be ineffective. This is due in part because the mechanical methods or chemical treatments that are used to remove or dissolve the minerals and bacteria causing the blockage of the aquifer only reach the face of the blocked aquifers. High pressure injection procedures have been developed to overcome this shortcoming by using sustained injection pressures of cleaning chemicals. The high pressure injection of the chemicals forces the chemical treatment to all sections of the well system and adjacent areas of the aquifers feeding ground water to the well. Injection rates from less than 100 gallons per minute (GPM) to over 4,000 GPM have been found to be necessary to effectively clean the wide range of potable water and industrial wells existing in the United States. The equipment necessary to perform the high pressure injection procedure at first involved the use of a 1,000 gallon tank, a 25 HP electric injection pump, a generator to power the pump, and a plurality of lengths of hoses and hose couplings required to connect the tank with the pump and connect the pump with the well. This prior art method of high pressure injection well cleaning was later improved to include a 2,000 gallon capacity tank and a 75 HP injection pump. However, these prior art methods all involved an external power source and proved to be inefficient due to the necessity of transporting the separate tank, generator, pump, and hose lengths and couplings to the well site and due to the constant changing of valves, fittings, and hoses required in rehabilitating the well.
SUMMARY OF THE INVENTION
The well rehabilitation apparatus of the present invention overcomes disadvantages encountered in prior art methods of rehabilitating water wells by providing a vehicle transporting the necessary equipment for high pressure injection cleaning of water wells. Generally, the apparatus of the present invention is comprised of a wheeled platform supporting a 3,000 capacity tank, a 135 HP hydraulic pump, a hydraulic motor connected to the pump, and a network of fluid conducting conduits connected between the tank and pump. The network of conduits includes a manifold having a plurality of branch conduits including an output conduit supplying liquid contained in the tank to the well being rehabilitated, an input conduit providing fluid communication back from the well to the manifold, a discharge conduit providing fluid communication from the manifold away from the vehicle and the well, and a return conduit providing fluid communication between the manifold and the tank interior. A pair of fill conduits are also communicated with the tank interior volume for use in filling the tank with a liquid. An operator's platform is provided at the rearward end of the vehicle. A plurality of manually operated valves are provided on the manifold branch conduits and the fill conduits enabling an operator of the apparatus standing on the platform to easy access any one of the plurality of valves to control the flow rate of liquid through the conduit associated with the valve.
The novel construction of the well rehabilitation apparatus of the invention enables an operator of the apparatus to stand on the platform off the ground's surface and operate the control valves and control the hydraulic pump from one location. Once a well treatment crew has connected hoses to and from the well to the manifold branch conduits, the operator can control all functions from the operator's platform. A flow of liquid can be recirculated in the tank for mixing chemicals, and injected into the well at variable rates, or discharged from the apparatus or directed to a test meter for test measurements.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and features of the present invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:
FIG. 1 is a top plan view of the apparatus of the invention;
FIG. 2 is a right side elevation view of the apparatus of the invention;
FIG. 3 is a front elevation view of the apparatus;
FIG. 4 is a rear elevation view of the apparatus;
FIG. 5 is a left side elevation view of the apparatus; and
FIG. 6 is a schematic representation of the network of fluid conducting conduits of the apparatus of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 through 5 show various views of the well rehabilitation apparatus 10 of the present invention. Generally, the apparatus is comprised of a wheeled vehicle 12, a large capacity tank 14 supported on the vehicle and a pumping system 16 also supported on the vehicle. The wheeled vehicle 14 in the preferred embodiment is a trailer. However, the apparatus of the invention is equally well suited to be supported on the chassis of a truck and it should be understood that referring to the apparatus as being supported on a wheeled vehicle 12 is intended to be interpreted broadly to include a trailer, truck or other similar type of transportation vehicle.
The wheeled vehicle, or trailer 12, as shown in the drawing figures is constructed in a conventional manner but with a reinforced chassis 18 to support the weight of the component parts of the invention, particularly the large capacity tank 14 when filled with liquid. The chassis 18 is supported for transportation by tandem wheels 20 on which the chassis is mounted by a conventional suspension system (not shown). A tongue assembly 22 projects from the forward end of the trailer chassis 18 and a hitch. 24 is provided on the tongue assembly for connection to a towing vehicle. Four manually operated jacks 26 are positioned around the chassis 18. As shown in FIG. 2, the jacks are lowered to maintain the chassis 18 in a horizontal orientation when the apparatus is being used in a well rehabilitation procedure and is not being transported. As shown in FIG. 5, the jacks 26 are raised when the apparatus is to be transported. The chassis 18 also supports a front platform 28 at the forward end of the trailer and a rear platform 30 at the rearward end of the trailer. Railings 32 extend around portions of the two platforms.
The tank 14 is shown having a rectangular configuration but may also have other configurations. The tank is constructed having a bottom 34, front and back walls 36, 38, a left sidewall 40 and right sidewall 42 and a top 44. Preferably, the tank is constructed of sheets of metal welded together in a fluid tight box configuration enclosing the interior volume 46 of the tank. A plurality of generally triangular gusset plates 48 are welded between the tank bottom 34 and left and right sidewalls 40, 42 to reinforce the tank and also provide obstructions in the tank interior that produce turbulence in the liquid injected into the tank. The tank bottom 34 slopes downward as it extends from the tank back wall to the tank front wall 36. A drain opening 50 is provided at the center of the tank bottom adjacent the front wall 36 and the slope of the tank bottom 34 causes liquid contained in the tank interior to flow to the drain opening 50. A screened enclosure 52 is formed around the drain opening 50 to prevent debris such as sand and gravel from draining through the drain opening 50. The screened enclosure has a plate top that prevents vortexing of the liquid drained through the opening. An access opening covered by a hatch 54 is provided through the tank top wall 44. A railing 56 extends around the tank top wall and front and rear ladders 58, 60 extend upward over the front wall 36 and back wall 38 of the tank to the tank top 44. In the preferred embodiment of the invention the tank interior volume 46 has a 3,000 gallon capacity.
The pumping system 16 includes an injection pump 64 mounted to the forward platform 28 of the vehicle. In the preferred embodiment of the invention the injection pump 64 has a power rating of 135 HP. The pumping system 16 also includes a motor 66 mounted on the front platform 28 and connected in a driving connection with the injection pump 64 to power the pump. In the preferred embodiment of the invention the motor is a hydraulic motor with a power rating of 125 HP. However, other types of motors may be employed with the apparatus of the invention, for example an electric powered or a gas or diesel powered motor, without departing from the intended scope of the invention defined by the claims. The pumping system has the capacity of pumping 3,000 gallons of liquid at a rate of over 4,000 GPM.
A network of fluid conducting conduits connects the pumping system 16 in fluid communication with the tank 14. The network employs a plurality of discharge outlets and fluid input couplings in performing the high pressure injection procedures involved in rehabilitating a well with the apparatus of the invention. The conduit network includes a pair of fill conduits, with one fill conduit 70 being a two inch diameter conduit operated by a manually operated valve A and the other fill conduit 72 being a four inch diameter conduit operated by a manually operated valve B. The two different size fill conduits are provided to enable the tank interior volume to be filled by coupling either of the two conduits to a water source, the use of the particular fill conduit depending on the source of water available. Both fill conduits 70, 72 can be used together or separately to fill the interior volume of the tank. The respective manual valves A, B of the fill conduits 70, 72 are used to open and close the conduits and adjust the rate of fluid flow through the conduits.
A first, intake conduit 76 extends between the tank drain opening 50 and the pump 64 and connects the tank interior volume in fluid communication with the pump. A second conduit 78 extends from the pump output 80 through the tank front wall 36, the tank interior volume 46, and through the tank back wall 38 to a manifold 82 connecting the manifold in fluid communication with the pump 64.
The manifold 82 has a plurality of branch conduits including a return conduit 86 providing fluid communication between the manifold 82 and the tank interior volume 46. Fluid communication between the manifold 82 and the return conduit 86 is controlled manually by a manual valve C provided on the return conduit. The valve C is operated manually to open or close fluid communication out through the manifold and the return conduit or to adjust the rate of fluid flow through the manifold and return conduit.
The return conduit 86 passes through the tank back wall 38 into the tank interior volume 46 and is connected in fluid communication with a distribution conduit 88 intermediate opposite ends of the distribution conduit. The distribution conduit 88 extends across the tank bottom 34 adjacent the tank back wall 38 to its opposite ends and has a pair of dispensing nozzles 90 connected at its opposite ends for dispensing liquid into the tank interior volume and mixing liquid in the volume.
The plurality of manifold branch conduits also includes an output conduit 92 or injection conduit that is adapted to be connected to the well (not shown) to be rehabilitated by the apparatus by a length of hosing (not shown), the output conduit and length of hosing connecting the manifold 82 and the well in fluid communication with each other. Fluid communication between the manifold 82 and well through the output conduit 92 and hosing is controlled by a manual valve D provided on the output conduit. Manual operation of the valve D opens and closes fluid communication between the manifold and well through the output conduit and attached length of hose and also adjusts the rate of fluid flow from the manifold through the output conduit and length of hose to the well.
The plurality of manifold branch conduits also includes an input conduit 96 or surge line that is also adapted to be connected in fluid communication with the well (not shown) by a length of hose (not shown). The input conduit 96 and attached length of hose provide fluid communication from the well back to the manifold 82. Fluid communication through the input conduit 96 is controlled by a manual valve E provided on the conduit. The manual valve E can be manually operated to open and close fluid communication from the well through the input conduit 96 and attached length of hose to the manifold 82 and can also control the rate of fluid flow through the input conduit to the manifold.
The plurality of manifold branch conduits also includes a discharge conduit 98 that branches off from the input conduit 96. As seen in the drawing figures the discharge conduit 98 branches off from the input conduit 96 between the manual valve E controlling fluid flow through the input conduit and the distal end of the input conduit that is connected in fluid communication with the well by a length of hose (not shown). The discharge conduit 98 directs fluid flow from the input conduit 96 away from the apparatus 10 and the well. The distal end of the discharge conduit 98 from its connection to the input conduit 96 may be connected to a length of hose (not shown) to further distance liquid discharged through the discharge conduit 98 away from the apparatus 10 and the well. The discharge conduit is provided with a manually operated valve F to control fluid flow through the conduit. The valve F can be manually operated to either close or open the discharge conduit 98 or adjust the rate of fluid flow through the conduit.
An additional manually operated valve G is provided on the input conduit 96 between the connection of the discharge conduit 98 to the input conduit 96 and the distal end of the input conduit that is communicated with the well through a length of hose (not shown). This additional manual valve G is manually operated to open and close fluid communication through the portion of the input conduit 96 extending between the connection of the discharge conduit 98 and the distal end of the input conduit, and to adjust the rate of fluid flow through this portion of the input conduit.
From the description provided above, it should be appreciated that all of the manually operated valves A-G are positioned on the network of fluid conducting conduits where they are all accessible manually by an operator of the apparatus standing on the rear platform 30. This enables the apparatus to be controlled by a single operator standing on the rear platform 30. Also accessible from the rear platform is an electric switch 102 mounted on the tank back wall 38 and connected electrically to a servo control (not shown) of the hydraulic motor 66 for selectively turning the motor on and off by depressing the switch. A pressure gauge 104 is mounted on the manifold 82 to provide the operator of the apparatus standing on the rear platform 30 a visual indication of the fluid pressure in the manifold. This novel arrangement of controls of the apparatus provides the operator of the apparatus standing on the rear platform 30 with easy access to all of the manually operated controls to control the operation of the apparatus in performing the high pressure injection procedures involved in rehabilitating a water well employing the apparatus.
In use of the apparatus 10 the vehicle trailer 12 is first transported to the site of the well to be rehabilitated by the apparatus. At the well site four external connections to the fluid conduit network of the apparatus are required. The connections include connecting a supply of water to one of the two fill conduits 70, 72, connecting the output conduit 92 to the well by a length of hose, connecting the input conduit 96 to the well pump by a length of hose, and connecting the discharge conduit 98 to a length of hose extending away from the apparatus 10 or to a metering apparatus if the discharge liquid pumped from the rehabilitated well is to be tested.
The configuration of the conduit network of the apparatus enables five functions to be performed by the single apparatus once the above-described connections are made. These functions include mixing chemicals to be used in the rehabilitation process with water inside the tank interior volume, injecting the liquid contained in the tank volume into the well, filling the tank interior volume directly from the well being rehabilitated, discharging the liquid contained in the tank through the discharged conduit, and discharging liquid contained in the well through the discharge conduit to a waste area remote from the apparatus and well or to metering apparatus to test the liquid discharged from the well. A schematic representation of the tank 14, the pumping system 16, and the fluid conduit network is provided in FIG. 6 to assist in the following explanation of the operation of the apparatus 10.
Each of the above-described functions is performed by a single operator of the apparatus standing on the rear platform 30 by manually manipulating the seven valves A-G and the pump motor on/off switch 102. In a typical use of the apparatus, chemicals to be mixed with water and used in the rehabilitation of the well are poured into the tank interior volume 46 through the access opening 54 in the top of the tank. Water is supplied to the tank interior for mixing with the chemicals by the external source of water connected to one of the two fill conduits 70, 72. By opening the corresponding manual valve A, B for the fill conduit connected to the source of water, the operator supplies water from the external source to the tank interior to be mixed with the chemicals. Once the tank is filled, the operator next activates the pump motor by depressing the electric switch 102. The pump motor 66 drives the injection pump 64 drawing liquid from the tank interior through the first conduit 76, the pump 64, and the second conduit 78 to the manifold 82. To thoroughly mix the chemicals and the water contained in the tank, the return conduit valve C is opened with the other valves closed. This will cause the liquid pumped from the tank to be recirculated through the manifold 82 and the return conduit 86 and then through the distribution conduit 88 and the pair of nozzles 90. The liquid output from the mixing nozzles 90 is directed against the Gussets 48 in the tank interior creating turbulence in the liquid contained in the tank and thoroughly mixing the water and chemicals.
With the liquid thoroughly mixed in the tank interior, it is next injected into the well to be rehabilitated. To perform the injection function of the apparatus, the manual valve D on the output conduit 92 is opened with all other valves being closed. This causes the contents of the tank to be pumped through the output conduit 92 and the length of hose connecting it with the well (not shown) into the well.
If surging of the well is required, the liquid which has been injected into the well can be pumped back out into the tank interior using the well pump (not shown) to pump surged liquid from the well through the input conduit 96. To perform the surging operation valves C, E and G are opened with all other valves closed. Liquid surged from the well will then be pumped by the well pump back into the tank interior volume.
To discharge the contents of the tank to a test meter or waste area through the discharge conduit 98 valves E and F are opened with all others closed. This will cause the tank contents to be pumped through the first conduit 76, the pump 64, the second conduit 78, the manifold 82, a portion of the input conduit 96 and the discharge conduit 98 to the meter or the waste area away from the apparatus and the well.
To pump the liquid in the well from the well to a waste area or to a test meter to evaluate the performance of the well cleaning procedure, the well pump (not shown) is used to pump the liquid from the well and to the input conduit 96 through the length of hose connecting the conduit with the well. The manual valves F and G are opened with all other valves closed. The well pump will cause liquid from the well to be pumped through the input conduit 96 and the discharge conduit 98 to the test meter or waste area away from the apparatus and the well.
All of the above described operations capable of being performed by the apparatus of the invention can be performed by a single operator standing on the rear platform 30 of the apparatus.
While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.
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A vehicle employed in the rehabilitation of water wells comprises a 3,000 gallon capacity tank and a 135 horsepower hydraulic pump connected in fluid communication with the tank through a network of fluid conducting conduits providing an apparatus that transports all of the necessary equipment to a water well location for rehabilitation of the well.
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BACKGROUND OF THE INVENTION
The present invention relates to a brake mechanism for an automatic washer and more particularly to a band brake for retarding motion of the wash basket.
In conventional vertical-axis automatic washers, there is a central agitator which oscillates during the wash portion of the cycle within a wash basket holding the materials to be washed, the wash basket being held in a fixed position relative to the washer cabinet by a brake. For example, U.S. Pat. No. 3,216,227 discloses a direct drive motor that drives an agitator by means of the motor shaft and drives the basket by means of a coupling between the motor housing and the basket. The basket is locked by a brake mechanism comprising a brake shoe controlled by a spring and a solenoid to selectively cause the shoe to engage a drum connected to the rotating wash basket so that the basket will be locked during agitation.
Band brakes are also utilized to provide the braking function in which one of the ends of the band is held in a fixed position and the other end is controlled by a spring and solenoid to selectively tighten or loosen the band to effect braking. A disadvantage of this type of brake arrangement is that the brake is capable of effective braking in only one direction of rotation. The brake drum can slip in the opposite direction even though the brake may be "on".
SUMMARY OF THE INVENTION
The present invention provides a band brake for an automatic washer which achieves effective braking in either direction of rotation of the wash basket. To accomplish this bidirectional braking, each end of the band is connected to a separate pivot bracket or crank. These two brackets are mounted on a common post and then connected via an extension spring that provides the braking tension. When the brake drum rotates in a counter-clockwise direction, for example, the left and right brackets rotate clockwise (due to the friction on the band brake) until the left end of the band is radially aligned with the center of the post. The extension spring then causes the band to provide braking in the clockwise direction.
When the brake drum reverses direction to the counter-clockwise direction, the two brackets pivot counter-clockwise until the right band end is radially aligned with the center of the post. The extension spring then provides the braking force in the counter-clockwise direction.
The pivot band brake may be placed in the "off" position by pulling the two radially inward release ends of the brackets together against the force of the extension spring. This provides the slack needed to allow the brake drum to rotate in the either direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration of an automatic washer embodying the principles of the present invention.
FIG. 2 is a side sectional view of the agitator and drive and brake system of the washer of FIG. 1.
FIG. 3 is a sectional view taken generally along the line III--III of FIG. 2.
FIG. 4 is a side elevational view taken generally along the line IV--IV of FIG. 3.
FIG. 5 is a sectional view similar to FIG. 3 illustrating the position of the pivot brackets and band brake when the basket is rotating in a clockwise direction.
FIG. 6 is a sectional view similar to FIG. 3 illustrating the position of the pivot brackets and band brake when the basket is rotating in a counter-clockwise direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is illustrated an automatic washer generally at 10 embodying the principles of the present invention. The washer has an outer cabinet 12 with an openable lid 13 which encloses an imperforate wash tub 14 for receiving a supply of wash liquid. Concentrically mounted within the wash tub is wash basket 16 for receiving a load of materials to be washed in a vertical axis agitator 18. A motor 20 is provided which is drivingly connected to the agitator 18 to drive it in an oscillatory or rotary manner and is also selectively connectable to the basket 16 to rotate or oscillate it. The assembly of tubs, agitator and motor is mounted on a suspension system 22. A plurality of controls 26 are provided on a control console 28 for automatically operating the washer through a series of washing, rinsing and liquid extracting steps.
The drive mechanism is shown in greater detail in FIG. 2 where it is seen that the motor 20 is connected by means of a drive belt 30 to a gear arrangement such as a planetary gear assembly 32 to a vertical shaft 34 connected to the agitator 18. In this particular drive arrangement, the motor 20 may be a permanent split capacitor (PSC) motor which is to be reversely operated to provide the oscillatory motion to the agitator and basket. The wash basket 16 is connected via a spin tube 36 to the gear arrangement 32, such as to an outer ring gear having an external generally cylindrical hub surface 44. The vertical shaft 34 is connected to planet gears through the use of a connecting carrier plate and a sun gear is directly connected to a shaft 48 connected to a pulley 50 which is rotated by the belt 30 connected to the motor 20.
When the washer is operating in the agitator mode, the motor 20 is operated in a reversing fashion which causes the shaft 48 to oscillate, thus driving the sun gear in alternating opposite directions. The agitator is therefore oscillated through its connection with the planet gears. The wash basket is held stationary during this operation and to provide the means for holding the basket 16 stationary, a band brake mechanism 52 shown best in FIGS. 3-6 is provided. The mechanism comprises a brake band 54 having a high friction interior lining 56 which is engageable with at least a portion of the circumference of the hub 44 connected to the basket 16. A first end 58 of the band 54 is pivotally connected to a first pivot bracket or crank 60 which is in turn pivotally connected to a fixed vertical post 62 forming a part of a frame 65 of the washer. A second end 64 of the band 54 is pivotally connected to a second pivot bracket or crank 66 which is also pivotally mounted on the post 62. Thus, no additional mounting hardware is required and the brackets can be installed on conventionally configured washing machines. The invention can also be employed in an environment wherein the two brackets 60, 66 are pivotally mounted at separate locations rather than having a common pivot such as post 62.
As seen best in FIG. 4, the first bracket 60 is formed generally in a U-shape with a top horizontal leg or wall 68, a bottom horizontal leg or wall 70 and a vertical bight leg or wall 72 interconnecting the two horizontal legs. Both the top and bottom legs have an aperture 74, 76, therethrough for being pivotally received on the post 62. The top and bottom legs each have a second aperture 78, 80 therethrough for receiving a vertically oriented pivot pin 82 to which is attached the first end 58 of the brake band 54.
As seen in the view of FIG. 3, the first pivot bracket 60 is configured such that the connecting bight leg 72 is positioned at a left side of the bracket adjacent to a left radially outward edge 84. The perimeters of the upper and lower legs are in vertical alignment from the left side of the radial outer edge along the bight leg 72 and radially inwardly to a radially inward edge 86 and along the radially inward edge to a point just to the right of the apertures 74, 76 for the post 62. The perimeter of the top leg 68 then angles radially outwardly and to the left, back toward the left radially outward edge 84. The bottom leg 70, however, proceeds radially outwardly, but extends somewhat to the right and has a right radially outward portion 86 with an aperture 88 therein. The perimeter of the lower leg 70 then proceeds in a concave arcuate manner as illustrated at 90 to the left radially outward edge 84.
The second pivot bracket 66 is configured somewhat similarly, although in a reverse manner. This second bracket 66 also has a top leg or wall 92 and a bottom leg or wall 94 with a connecting bight leg or wall 96. The top and bottom legs have apertures 98, 100 therethrough for receiving the post 62 and they have apertures 102, 104 for receiving a vertically oriented pivot pin 106 to which the second end 64 of the brake band 54 is attached. The height of the bight leg 72 of the first bracket 60 and the bight leg 96 of the second bracket 66 is the same so that the spacings of the two top and bottom legs is identical. The two brackets are arranged so as to be overlapping such that the top leg 68 of the first bracket 60 overlies the top leg 92 of the second bracket 66 and the bottom leg 70 of the first bracket 60 overlies the bottom leg 94 of the second bracket 66.
The bight leg 96 of the second bracket is positioned, from the vantage point of FIG. 3, at the right radially outward edge 108. Again, the top and bottom walls have perimeters in alignment along the bight leg 96 and radially inwardly to a radially inward end 110 and along the radial inward end to a point just to the left of the apertures 98, 100. The top leg angles radially outwardly and rightwardly back toward the radial outward end 108 from a point just to the left of the post aperture 98, but the bottom wall 94 extends radially outwardly and somewhat to the left to end in a left radially outward edge 112. The perimeter of the bottom wall then extends in a concave arcuate manner indicated at 114 back toward the right radially outward edge 108.
The centers of the apertures 78, 80 and 102, 104 for the pivot pins 82, 106 are positioned radially inwardly of the centers of the apertures for the post 62. A spring 116 is attached at either end to the bight legs 72, 96 and operates to continuously bias those two walls towards each other. Thus, a line connecting the spring attachment point, the post 62 centerpoint and the pivot pin centerpoint has an L-shape so that the bracket functions as a bell crank.
An actuator mechanism is provided to overcome the bias of the spring to turn the brake "off". A Bowden cable 118 has its outer sheath 120 secured to the left radially outward edge portion 112 of the lower leg 94 of the second bracket 66 by a clamp 122 and its cable portion 124 is captured in the aperture 88 near the right radially outward edge 86 of the lower wall 70 of the first bracket 60. A solenoid 126 is operatively connected to the cable 124 to selectively withdraw or extend it from the sheath 120. If the cable 124 is drawn into the sheath, the first bracket 60 will be pivoted clockwise on the post 62 relative to the second bracket 66. This will result in the two sets of apertures 78, 80 and 102, 104 being moved towards each other thereby loosening the brake band 54 on the hub 44 to reduce or eliminate any braking effect of the band on the hub. Thus, the bias of the spring 116 is overcome.
When the cable is extended from the sheath then the spring 116 will cause the two bight legs to move towards each other and therefore the two sets of apertures 78, 80 and 102, 104 move away from each other, thus tightening the band 54 on the hub.
The mounting arrangement of the two ends 58, 64 of the band 54 and the two brackets 60, 66 permits the brake to be effective in either rotational direction of the hub 44. As illustrated in FIG. 5, when the hub rotates in a clockwise direction, the first and second brackets are caused to rotate about the post 62 in a clockwise direction (due to the friction on the brake band 54). This rotation of the bracket will continue until the first end 58 of the band is in radial alignment with the center of the post 62 causing the pin 82 to act as a fixed mounting post assuring effective braking in that direction. When the hub begins to rotate in a counter-clockwise direction, the two brackets will also rotate about the hub 62 in a counter-clockwise direction until the second end 64 of the band 54 is in radial alignment with the center of the post 62, shown in FIG. 6. At that point, the pivot pin 106 will act as a fixed attachment point assuring effective braking of the hub in a counter-clockwise direction.
Thus, the present arrangement provides for effective braking in either direction of rotation of the wash basket and hub with a relatively simple assembly and limited number of parts which are adapted to be incorporated into conventionally configured washing machines.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.
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A brake mechanism for an automatic washer is provided wherein a brake band is engageable with a hub attached to the wash basket and has both of its ends pivotally mounted on pivot brackets so that braking is effective in either rotational direction of the basket. A spring interconnects the two brackets to continuously bias the band into tight engagement with the hub and a solenoid operated actuator is provided to overcome the force of the spring to loosen the brake. The brackets are mounted on a common pivot post so that one of the band ends will be pulled into radial alignment, by pivoting of the brackets, in either direction of rotation of the basket. This causes the mounting to act as a fixed mount increasing the bidirectional effectiveness of the brake.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to fishing lures, specifically to what are commonly called spinnerbaits.
[0003] 2. Description of the Prior Art
[0004] Prior art related to various fishing lures, some of which may be relevant to the present invention, are disclosed in U.S. Pat. No. 4,201,008 to Sparkman which discloses a plurality of conventional spinners. In addition, U.S. Pat. No. 4,209,932 to Pate as well as U.S. Pat. No. 4,773,180 to Shimizu discloses spinner lures with plural blades. U.S. Pat. No. 5,024,019 to Rust discloses a fishing lure with a blade and a sound generating rattle. U.S. Pat. No. 4,011,681 to Johnson discloses a fishing lure with a blade and a spring element in one portion of the support rod (main shaft) for increased flexibility. U.S. Pat. No. 5,647,163 to Gorney discloses a spinner lure with a stainless wire main shaft.
[0000]
520178
Spinnerbait fishing lure
April, 1993
Mcwilliams
666597
Spinnerbait fishing lure
November 2001
Hammond
540054
Fishing lure system with
October 1993
Johnson
flexible support rod
514670
Weedless fishing lure
September 1992
Hilliard
apparatus
5,113,606
Scented lure
May 1992
Rinker
481523
Fish lure
March 1989
Pingel
480533
Sonic fishing lure
February 1989
Fuentes
464004
Spinner bait with arms
February 1987
Stanley
of different diameter
457187
Fishing lure
February 1986
Montgomery
420993
Spinner bait fishing lure
June 1978
Pate
420100
Fishing lure and spinner
January 1979
Sparkman
502401
Spinner bait lure with
June 1989
Rust
rattle pod
4,011,681
Fishing lure
October 1975
Johnson
[0005] Fishing lures, including “V” shape fishing lure assemblies such as spinnerbaits, are known in the prior art. However, most spinnerbaits which are found in prior art and in industry today embody shafts or shanks (arms) made of relatively rigid material (such as stainless steel wire), which is less flexible than the type of main shaft used in the present invention (flexible shaft), and which can become deformed or break after continued use, thus adversely affecting the overall desired performance of the lure assembly.
[0006] Of all the above-mentioned patented inventions, two patents with flexible support rods, relevant to the present invention, have been submitted (U.S. Pat. No. 5,400,542 to Johnson and U.S. Pat. No. 6,665,977 to Hammond). They, however, are substantially different in their concepts or designs or results.
[0007] U.S. Pat. No. 5,400,542 to Johnson (Fishing lure system with flexible support rod) differs in its concept, in its design (“U” shape configuration) and in its results as it does not incorporate a “V” shape stabilizer for maintaining the desired “V” shape configuration (versus a “U” shape) as in the present invention. The diameter of the main flexible shaft may also be smaller than that which is embodied in the present invention and may thus cause distortion of the shanks of the “U” shape configuration of the assembly and lead to instability and malfunction of the entire assembly when pulled through water.
[0008] U.S. Pat. No. 6,665,977 to Hammond (Spinnerbait fishing lure) differs in its concept, in its design (a straight flexible shaft configuration intended to bend when pulled through water) and in its results as it does not incorporate a “V” shape stabilizer for maintaining the desired “V” shape configuration, as in the present invention, and, due to its concept and design, may lead to instability of the entire assembly when pulled through water.
SUMMARY OF THE INVENTION
[0009] This invention, which relates to fishing lures in general, specifically to what are commonly called spinnerbaits, and more specifically to flexible spinnerbait assemblies, is a spinnerbait assembly with a main flexible shaft onto which is incorporated, along its length, a rigid or semi rigid “V” shape stabilizer which 1) assures the assembly maintains the desired “V” shape and 2) allows for attachment of the fishing line to the lure. The present invention embodies two designs for the “V” shape stabilizer, both of which accomplish the same task, with essentially the same results, and can be used interchangeably for the assembly. Compared to existing spinnerbaits, the present invention maintains the desired “V” shape in its relaxed state as well as when pulled through water and is thus more stable and thus more efficient. The main flexible shaft may be of diameters greater than or equal to 0.041 inch and may be made of any material or combination of materials (such as flexible nylon coated stainless steel wire) which allows for the desired flexibility. The “V” shape stabilizer may be made of any material or combination of materials which allows for the desired rigidity necessary to maintain the “V” shape of the assembly, and, depending on the desired overall configuration of the assembly, the “V” shape stabilizer can be of different lengths and can be incorporated anywhere along the length of the main flexible shaft, thus allowing for different lengths of the two shanks comprising the “V” shape. Generally, to one extremity of the main flexible shaft, or along its corresponding shank, is incorporated a fish attracting head shape weight with 2-D or 3-D eyes, coupled with a hook or hooks, and hook skirt or Buck Tail, and in some cases, additional fish attracting components such as an artificial bumble bee. To the other extremity of the main flexible shaft and along its corresponding shank, are incorporated combinations of beads, clevises, blades, jingle bells and a single or double barrel sleeve which forms a loop to hold a crane swivel, barrel swivel or ball bearing swivel on which is attached a blade or blades. The aforementioned components of the assembly can be of various arrangements, shapes, sizes, lengths and materials which can be color coordinated in a manner most effective for catching a particular species of fish in a given fishing situation.
[0010] Compared to flexible spinnerbait assemblies which currently exist on the market and in prior art, the main innovations of the present flexible spinnerbait assembly, are 1) the diameter of the main flexible shaft, which is larger than that used in, for example, the flexible lure embodied in U.S. Pat. No. 5,400,542, and 2) the newly invented “V” shape stabilizer, which has not been seen in prior art or on the market. Both innovations, in combination, enable the spinnerbait assembly to more effectively maintain its desired “V” shape configuration when pulled through water (versus U.S. Pat. No. 6,665,977, for example) and provides the assembly with greater overall stability. When the assembly is pulled through water, the “V” shape angle is reduced depending on the retrieve speed of the angler and the pressure caused by the water against the lure, but it still holds its “V” shape configuration. When slack is provided to the fishing line, the lure assumes a wider “V” shape configuration, and when the spinnerbait assembly is in its relaxed position, it assumes its initial wider “V” shape configuration. The “V” shape stabilizer, which maintains the assembly's “V” shape while being pulled through water, also assures that the two shanks and the corresponding assembly components do not become entangled while in use. Compared to spinnerbaits with rigid shafts, the higher flexibility of the main flexible shaft of the present invention helps to reduce the risk of undesired distortion or breakage of the shanks with increased use, thus allowing for longer lasting overall stability and desired performance of the assembly, which in turn produces steadier and smoother natural vibrations which are commonly known to attract fish. The preferred positioning of the components, in combination with the main flexible shaft and the “V” shape stabilizer also provide increased vertical stability of the assembly when pulled through water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) comprising the flexible shaft spinnerbait assembly, showing each of the two preferred designs of the “V” shape stabilizer.
[0012] FIG. 2 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration.
[0013] FIG. 3 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration and the preferred arrangement of basic fish-attracting components.
[0014] FIG. 4 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration, the preferred arrangement of basic fish-attracting components and additional fish-attracting components and a trailer hook.
[0015] FIG. 5 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration, the preferred arrangement of basic fish-attracting components and a trailer hook with a hook skirt.
[0016] FIG. 6 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration, the preferred arrangement of basic fish-attracting components and a trailer hook, as well as Buck Tail.
[0017] FIG. 7 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the basic preferred fish attracting head shape weight with integrated hook and eyelet configuration, the preferred arrangement of basic fish-attracting components and a bumble bee assembly.
[0018] FIG. 8 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the preferred arrangement of basic fish-attracting components, but with a variation of the method by which the fish attracting head shape weight with integrated hook is attached to the main assembly.
[0019] FIG. 9 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the preferred arrangement of basic fish-attracting components, but with yet another variation of the method by which the fish attracting head shape weight with integrated hook is attached to the main assembly.
[0020] FIG. 10 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the preferred arrangement of basic fish-attracting components, but with the fish attracting head shape weight incorporated directly onto the main shaft of the assembly and the hook separately attached to the end of main shaft.
[0021] FIG. 11 is a side view depicting the preferred assembly and configuration of the main parts (skeleton) of the flexible shaft spinnerbait assembly, showing one of the two preferred designs of the “V” shape stabilizer and comprising the preferred arrangement of basic fish-attracting components, but with the fish attracting head shape weight attached to the end of main shaft and the hook attached to the fish attracting head shape weight in the fashion depicted.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Its functional advantages:
[0023] This Flexible Shaft Spinnerbait Fishing Lure Assembly With “V” Shape Stabilizer is unlike other conventional spinner baits, generally maintaining its intended “V” shape configuration and remaining in a vertical position while being pulled through water, with its weighted side remaining generally downward and the main fish attracting blade components at the opposite extremity of the weighted side remaining generally upward while being pulled through water while both shanks of the main flexible shaft move up and down depending on the speed with which the assembly is being pulled through the water. The faster the assembly is retrieved through water the more compact it becomes, yet it maintains its “V” shape configuration and the assembly remains vertical without rolling from side to side (laterally). When being pulled through water slowly, the assembly retains a wider “V” shaped configuration and still remains vertical without rolling from side to side.
[0024] This spinnerbait fishing lure produces more desirous fish attracting vibrations, much more so than the standard “hard” wire spinnerbaits made of stainless steel or other rigid or semi rigid metals. This is mainly due to the fact that both shanks of the Flexible Shaft Spinnerbait Fishing Lure Assembly With “V” Shape Stabilizer are highly flexible, thus more effectively interacting with the natural surrounding forces, thus generating more natural vibrations. Such natural vibrations are known to attract fish.
[0025] As with most types of lures, when a fish is initially attracted to a spinnerbait assembly, it often bumps into it seeking out the bait. When a fish bumps into a standard “hard” wire spinnerbait assembly seeking the bait, it must move against the entire rigid “V Shape Frame” of the assembly to seek the bait in order to eventually get properly hooked. With the two flexible shanks of the main flexible shaft of the present invention, which are held in position with the “V” shape stabilizer, the spinnerbait arms are free to easily move laterally, up and down, and generally in any direction, thus, when the fish initially bumps into the assembly seeking the bait, it encounters less resistance and becomes more easily hooked. When a fish gets hooked to a lure, it will often jump to try to get rid of it. Generally, standard “hard” wire spinnerbait assemblies are formed from one piece of solid rigid wire which is bent into a “V shape frame” making the assembly relatively inflexible and thus making it easier for the fish to shake it off due to its inflexibility. With the present invention and its innovative flexible, yet stable, design, when a hooked fish jumps, the fish has a very difficult time shaking it off. What is noticed when using the present invention is that most fish will hook themselves just by bumping into it and will stay hooked ⅘ or 9/10 times.
[0026] Unlike the relatively few flexible spinnerbaits fishing lures which exist on the market, this present invention, due to its incorporated “V” shape stabilizer and its overall preferred configuration, permits the assembly to maintain its “V” shape configuration, with the two flexible shanks of the main flexible shaft also free to swing about in many directions, while keeping both shanks with their corresponding integrated or attached components at appropriate distances away from each other such that self entanglement of the shanks and their components is avoided.
[0027] Referring to FIG. 1 : The present invention comprises of a main flexible shaft 2 , which has a minimum diameter of 0.041 inches and which is made of any material or combination of materials (such a plastic or nylon coated stainless steel wire) which allows for the desired flexibility of the shaft and its two shanks, onto which is incorporated a “V” shape stabilizer 1 or 1 A onto which is attached the fishing line. The main flexible shaft can be of any length, depending on the usage needs or requirements, which depend mainly on the type of fish being fished and the fishing conditions (for example, rapids, calm lakes, etc.). Depending on the desired configuration, the angle at which the “V” shape stabilizer 1 or 1 A is bent or molded or formed into allows for the flexible main shaft 2 to remain bent into a “V” shape at an angle of between approximately 45 and 120 degrees, and allows the entire assembly to generally maintain the desired “V” shape both in its relaxed position and while the lure assembly is being pulled through water. The tubing used to create the “V” shape stabilizer 1 is made of any material or combination of materials (for example, brass, plastic or carbon fiber resin) which is rigid enough to assure that the main flexible shaft 2 , with its two corresponding shanks, retains its desired “V” shape, and which is malleable enough to be bent into a “V” shape 1 , which includes the desired partially open eyelet onto which the fishing line is attached, and crimped or clamped into the desired position along the main flexible shaft 2 . The tubing used to form the “V” shape stabilizer 1 is slid onto the main flexible shaft 2 and positioned at a desired point along the main flexible shaft, and then, with the appropriate tools, the tube is bent to its desired shape 1 and crimped or clamped into position. The “V” shape stabilizer 1 A is made of any material or combination of materials (for example, plastic, carbon fiber, bismuth, etc.) which allow the “V” shape stabilizer 1 A, which is designed with an eyelet onto which the fishing line is attached, to be molded or formed directly onto the desired location along the main flexible shaft 2 . The material or combination of materials used to form the “V” shape stabilizer 1 or 1 A are also selected such that the assembly achieves the desired level of floatability when being pulled through water. Depending on the desired usage of the spinnerbait, which often depends of the type of fish desired to attract (for example, some types of fish tend to stay nearer the bottom of a lake and others tend to remain closer to the surface), the combination of the weight and density of the material or combination of materials used to form the “V” shape stabilizer 1 or 1 A will in part determine the degree of floatability of the assembly in water. The main flexible shaft 2 can be of any diameter greater or equal to 0.041 inches and the tubing used for forming the “V” shape stabilizer 1 has a slightly larger inside diameter relative to the diameter of the main flexible shaft 2 such that the main flexible shaft 2 can slide freely yet snugly through the tubing before forming and clamping or crimping. Depending on fishing requirements and depending on the desired size and configuration of the assembly, the main flexible shaft 2 and the tube used to form the “V” shape stabilizer 1 can vary in length, color or combination of colors suited for attracting different varieties of fish in varying fishing conditions. Wound thread, with or without glue or varnish, or a shrinkable tubing ring 12 with or without glue, or any equivalent or similar method of attachment is added to the “V” shape stabilizer 1 in order to close the partially open eyelet and thus better secure the fishing line to the spinnerbait assembly.
[0028] Referring to FIG. 2 : FIG. 2 shows the preferred basic embodiment of the spinnerbait assembly where the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 and integrated hook 6 is molded directly onto one extremity of the main flexible shaft 2 . In all configurations of the assembly, even when the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 , with or without an integrated hook 6 is attached to the same extremity of the main flexible shaft 2 by different means (such as in FIGS. 8 , 9 , 10 and 11 ), the opposing extremity of the main flexible shaft 2 is bent into a loop and crimped or clamped into position with a single or double barrel sleeve 3 .
[0029] Referring to FIG. 3 : Prior to bending that extremity of the main flexible shaft 2 into a loop and securing it with the single or double barrel sleeve 3 , beads 7 and a clevis 8 with a blade 9 are incorporated to this shank of the main flexible shaft 2 by sliding them over the main flexible shaft 2 and a blade 11 or a set of blades is attached to the loop by coupling with a crane swivel 10 , barrel swivel 10 or ball bearing swivel 10 . Although usually made of metal for fishing lure applications, the blades 9 and 11 , the clevis 8 , and the single or double barrel sleeve 3 and the swivel 10 , as well as the beads 7 , could be made of any other material or combination of materials that duplicate the desired use and efficiency of the these components. All aforementioned components can be of varying sizes, shapes and colors, and can be color combined as desired for attracting different varieties of fish in varying fishing conditions.
[0030] Referring to FIG. 4 : A trailer hook 13 is added to the assembly by attaching it to the integrated hook 6 protruding from the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 and securing it in place with a shrinkable tubing ring hook keeper 14 with or without glue such that the trailer hook has freedom of movement but does not fall off. This feature adds to the fish attracting qualities (additional movement) of the assembly. A jingle bell 25 , which attracts certain types of fish, is attached to a clevis 8 with a split ring 24 , which in turn is attached to the main flexible shaft prior to creating the loop which is held in position with a single or double barrel sleeve 3 .
[0031] Referring to FIG. 5 : FIG. 5 is similar to FIG. 4 , but with two differences: 1) the jingle bell 25 , the clevis 8 onto which the jingle bell 25 is attached, and the split ring 24 which joins the jingle bell 25 to the clevis 8 are removed, and 2) a hook skirt 15 (another fish attracting component) is added to the assembly near the base of the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 nearest the integrated hook 6 by a variety of means depending on the type of hook skirt 15 used.
[0032] Referring to FIG. 6 : FIG. 6 depicts essentially the same assembly as seen in FIG. 5 , with or without the trailer hook 13 , but with buck tail 17 (another fish attracting component) added to the assembly by tying it with tying thread 16 near the base of the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 nearest the integrated hook 6 . Varnish or glue is applied to the thread to further secure it in place.
[0033] Referring to FIG. 7 : FIG. 7 depicts essentially the same assembly as FIG. 3 but incorporates an artificial bumble bee assembly which is set onto the hook 6 by inserting the hook 6 through the bumble bee assembly. The bumble bee assembly, which comprises the bumble bee body 18 , hackle 19 , trolling wire 20 and a treble hook 21 , can be assembled separately, and then inserted onto the hook 6 , or it can be assembled directly onto the hook 6 and secured with tying thread and/or glue and/or shrinkable rubber tubing.
[0034] Referring to FIG. 8 : FIG. 8 depicts an assembly similar to that which is depicted in FIG. 3 , but with one main difference: The fish attracting head shape weight 4 with 2-D or 3-D eyes 5 with an integrated hook 6 is attached to the main flexible shaft 2 by means of a split ring 24 attached to a second loop formed by crimping or clamping a single or double barrel sleeve 3 on the same extremity of the main flexible shaft 2 where, in all heretofore Figures, the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 is directly molded onto the main flexible shaft 2 . This configuration allows for increased movement of the spinnerbait assembly, another additional fish attracting feature.
[0035] Referring to FIG. 9 : FIG. 9 depicts an assembly similar to that which is depicted in FIG. 8 , but with one difference: The fish attracting head shape weight 4 with 2-D or 3-D eyes 5 with an integrated hook 6 is attached to the loop of the same extremity of main flexible shaft 2 by means of a crane swivel 10 , barrel swivel 10 or ball bearing swivel 10 instead of by means of a split ring 24 . As in FIG. 8 , this configuration allows for increased movement of the spinnerbait assembly, another additional fish attracting feature.
[0036] Referring to FIG. 10 : FIG. 10 depicts an assembly similar to that depicted in FIG. 9 , but where the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 , without an integrated hook, is molded directly onto the corresponding shank of the main flexible shaft 2 , and a hook 6 is attached to the corresponding loop by clamping the hook 6 directly onto the loop.
[0037] Referring to FIG. 11 : FIG. 11 depicts an assembly similar to that depicted in FIG. 9 , but in which the fish attracting head shape weight 4 with 2-D or 3-D eyes 5 , attached to the main flexible shaft 2 in the same way as depicted in FIG. 9 , has integrated onto it a wire clip 26 instead of an integrated hook. The hook 6 is instead attached to the wire clip 26 by means of a crane swivel 10 , barrel swivel 10 or ball bearing swivel 10 .
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A flexible shaft spinnerbait fishing lure assembly comprising a main flexible shaft of a minimum diameter of 0.041 inch onto which is incorporated, along its length, a rigid or semi rigid “V” shape stabilizer, onto which is integrated an eyelet onto which the fishing line is attached, and which serves to maintain the “V” shape of the spinnerbait assembly, resulting in little to no deformation or breakage of the assembly with continued use. The preferred positioning of the stabilizer and its preferred fish attracting head shape weight, hook and fish attracting components configurations allow for increased overall stability of the assembly, including vertical stability when being pulled through water. Due to this increased stability, the flexible spinnerbait assembly also generates, with greater consistency, the frequencies desired to increase fish attraction.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2015-0170976, filed with the Korean Intellectual Property Office on Dec. 02, 2015, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a power transmission apparatus for a vehicle. More particularly, the present disclosure relates to a power transmission apparatus for a vehicle that realizes ten forward speed stages and one reverse speed stage using three synchronizers and two planetary gear sets.
BACKGROUND
[0003] Environmentally-friendly traits of vehicles are very important technologies on which the motor industry is dependent. Vehicle makers are focusing on development of environmentally-friendly vehicles to meet environment and fuel consumption regulations.
[0004] Some examples of future vehicle technologies include electric vehicles (EV) and hybrid electric vehicles (HEV) that use electrical energy, and double clutch transmissions (DCT) that improve efficiency and convenience.
[0005] The DCT may include two clutch devices and a gear train of a manual transmission. The DCT may selectively transmit torque input from an engine to two input shafts through two clutches, change the torque selectively transmitted to the two input shafts through the gear train, and output the changed torque.
[0006] The DCT may be used to realize a compact transmission achieving a forward speed stage higher than a fifth forward speed stage. The DCT may be used as an automated manual transmission that does not require a driver's manual manipulation by controlling two clutches and synchronizing devices by a controller.
[0007] Compared with an automatic transmission with planetary gear sets, the DCT has excellent power delivery efficiency, simplifies changing and adding components for achieving multiple gear stages, and improves fuel economy.
[0008] The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure 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
[0009] The present disclosure has been made in an effort to provide a power transmission apparatus for a vehicle having advantages of achieving ten forward speed stages and a reverse speed stage, realizing multiple speed stages, and improving fuel economy by adding two planetary gear sets to a DCT including three synchronizers.
[0010] Another embodiment of the present disclosure provides a power transmission apparatus for a vehicle having further advantages of simplifying an interior layout and minimizing weight of the power transmission apparatus by reducing the number of components, and of improving fuel economy by achieving ten forward speed stages and one reverse speed stage with three synchronizers and two planetary gear sets.
[0011] A power transmission apparatus for a vehicle according to an exemplary embodiment of the present disclosure may include: a first input shaft directly connected to an engine; a second input shaft enclosing the first input shaft rotating independently from the first input shaft and selectively receiving torque of the engine through a first clutch; a third input shaft enclosing the second input shaft rotating independently from the second input shaft and selectively receiving the torque of the engine through a second clutch; an intermediate shaft disposed in parallel with the first, second, and third input shafts; a transfer gear fixedly disposed on the intermediate shaft and outputting torque of the intermediate shaft; a first shifting member receiving the torque of the engine from the second input shaft, changing the torque of the engine into first and second preliminarily shifted torques, and outputting the first and second preliminarily shifted torques; a second shifting member receiving the torque of the engine from the third input shaft, changing the torque of the engine into third, fourth, and fifth preliminarily shifted torques, and outputting the third, fourth, and fifth preliminarily shifted torques; and a third shifting member changing the torque of the engine selectively transmitted from the first input shaft and the first preliminarily shifted torque to the fifth preliminarily shifted torque selectively transmitted from the first shifting member or the second shifting member into ten forward speed stages and one reverse speed stage, and outputting the ten forward speed stages and the one reverse speed stage.
[0012] The first shifting member may include: a 1/9 drive gear rotatably disposed on the second input shaft; a 3/7 drive gear rotatably disposed on the second input shaft and engaged with the transfer gear on the intermediate shaft; a first synchronizer operably connecting the 1/9 drive gear or the 3/7 drive gear to the second input shaft selectively; and a 1/9 driven gear fixedly disposed on the intermediate shaft and engaged with the 1/9 drive gear.
[0013] In one aspect, the second shifting member may include: a 2/8 drive gear, a 4/6 drive gear and a 10/R drive gear fixedly disposed on the third input shaft; a 2/8 driven gear rotatably disposed on the intermediate shaft and engaged with the 2/8 drive gear; a 4/6 driven gear rotatably disposed on the intermediate shaft and engaged with the 4/6 drive gear; a second synchronizer operably connecting the 2/8 driven gear or the 4/6 driven gear to the intermediate shaft selectively; a 10/R driven gear rotatably disposed on the intermediate shaft and operably connected to the 10/R drive gear through an idle gear on an idle shaft; and a third synchronizer operably connecting the 10/R driven gear to the intermediate shaft selectively.
[0014] In another aspect, the second shifting member may include: a 2/8 drive gear, a 4/6 drive gear and a 10/R drive gear rotatably disposed on the third input shaft; a second synchronizer operably connecting the 2/8 drive gear or the 4/6 drive gear to the third input shaft selectively; a third synchronizer operably connecting the 10/R drive gear to the third input shaft selectively; a 2/8 driven gear fixedly disposed on the intermediate shaft and engaged with the 2/8 drive gear; a 4/6 driven gear fixedly disposed on the intermediate shaft and engaged with the 4/6 drive gear; and a 10/R driven gear fixedly disposed on the intermediate shaft and operably connected to the 10/R drive gear through an idle gear on an idle shaft.
[0015] The third shifting member may include: a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear as rotation elements thereof; a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear as rotation elements thereof; four rotation shafts directly connected to at least one rotation element among the rotation elements of the first planetary gear set and the second planetary gear set; and frictional elements, any one of the frictional elements selectively connecting any one rotation shaft among the four rotation shafts to the first input shaft and the other of the frictional elements selectively connecting another rotation shaft among the four rotation shafts to a transmission housing.
[0016] Each of the first planetary gear set and the second planetary gear set may be a single pinion planetary gear set.
[0017] The four rotation shafts may include: a first rotation shaft directly connected to the first sun gear and selectively connected to the transmission housing; a second rotation shaft directly connecting the first planet carrier to the second ring gear and directly connected to an output shaft; a third rotation shaft directly connecting the first ring gear to the second planet carrier and selectively connected to the first input shaft; and a fourth rotation shaft directly connected to the second sun gear and receiving torque from the first shifting member and the second shifting member.
[0018] The frictional elements may include: a third clutch disposed between the first input shaft and the third rotation shaft; and a brake disposed between the first rotation shaft and the transmission housing.
[0019] A power transmission apparatus for a vehicle according to another exemplary embodiment of the present disclosure may include: a first input shaft directly connected to an engine; a second input shaft enclosing the first input shaft rotating independently from the first input shaft and selectively receiving torque of the engine through a first clutch; a third input shaft enclosing the second input shaft rotating independently from the second input shaft and selectively receiving the torque of the engine through a second clutch; an intermediate shaft disposed in parallel with the first, second, and third input shafts; a transfer gear fixedly disposed on the intermediate shaft and outputting torque of the intermediate shaft; a first shifting member including at least two drive gears rotatably disposed on the second input shaft, at least one driven gear fixedly disposed on the intermediate shaft, and at least one synchronizer selectively connecting any of the at least two drive gears to the second input shaft, wherein one of the at least two drive gears is engaged with the transfer gear and the other of the at least two drive gears is engaged with the at least one driven gear; a second shifting member including at least two drive gears fixedly disposed on the third input shaft, at least two driven gears rotatably disposed on the intermediate shaft, and at least one synchronizer selectively connecting any of the at least two driven gears to the intermediate shaft, wherein one of the at least two drive gears is operably connected to one of the at least two driven gears through an idle gear and another of the at least two drive gears is engaged with another of the at least two driven gears; and a third shifting member receiving torque of the first shifting member or the second shifting member from the drive gear engaged with the transfer gear, selectively receiving the torque of the engine from the first input shaft, and changing and outputting the torque received from the first shifting member or the second shifting member and the torque of the engine.
[0020] The at least two drive gears of the first shifting member may include a 1/9 drive gear and a 3/7 drive gear, the at least one driven gear of the first shifting member may include a 1/9 driven gear, and the at least one synchronizer of the first shifting member may include a first synchronizer.
[0021] The 1/9 drive gear may be engaged with the 1/9 driven gear, the 3/7 drive gear may be engaged with the transfer gear, and the first synchronizer may selectively connect the 1/9 drive gear or the 3/7 drive gear to the second input shaft.
[0022] The at least two drive gears of the second shifting member may include a 2/8 drive gear, a 4/6 drive gear, and a 10/R drive gear, the at least two driven gears of the second shifting member may include a 2/8 driven gear, a 4/6 driven gear, and a 10/R driven gear, and the at least one synchronizer of the second shifting member may include second and third synchronizers.
[0023] The 2/8 drive gear may be engaged with the 2/8 driven gear, the 4/6 drive gear may be engaged with the 4/6 driven gear, the 10/R drive gear may be operably connected to the 10/R drive gear through the idle gear, the second synchronizer may selectively connect the 2/8 driven gear or the 4/6 driven gear to the intermediate shaft, and the third synchronizer may selectively connect the 10/R driven gear to the intermediate shaft.
[0024] The third shifting member may include: a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear as rotation elements thereof; a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear as rotation elements thereof; four rotation shafts directly connected to at least one rotation element among the rotation elements of the first planetary gear set and the second planetary gear set; and frictional elements, any one of the frictional elements selectively connecting any one rotation shaft among the four rotation shafts to the first input shaft and the other of the frictional elements selectively connecting another rotation shaft among the four rotation shafts to a transmission housing.
[0025] Other rotation shaft among the four rotation shafts may be directly connected to the drive gear engaged with the transfer gear.
[0026] The four rotation shafts may include: a first rotation shaft directly connected to the first sun gear and selectively connected to the transmission housing through a brake; a second rotation shaft directly connecting the first planet carrier to the second ring gear and directly connected to an output shaft; a third rotation shaft directly connecting the first ring gear to the second planet carrier and selectively connected to the first input shaft through a third clutch; and a fourth rotation shaft directly connected to the second sun gear and receiving torque from the first shifting member and the second shifting member.
[0027] A power transmission apparatus for a vehicle according to another exemplary embodiment of the present disclosure may include: a first input shaft directly connected to an engine; a second input shaft enclosing the first input shaft rotating independently from the first input shaft and selectively receiving torque of the engine through a first clutch; a third input shaft enclosing the second input shaft rotating independently from the second input shaft and selectively receiving the torque of the engine through a second clutch; an intermediate shaft disposed in parallel with the first, second, and third input shafts; a transfer gear fixedly disposed on the intermediate shaft and outputting torque of the intermediate shaft; a first shifting member including at least two drive gears rotatably disposed on the second input shaft, at least one driven gear fixedly disposed on the intermediate shaft, and at least one synchronizer selectively connecting any of the at least two drive gears to the second input shaft, wherein one of the at least two drive gears is engaged with the transfer gear and the other of the at least two drive gears is engaged with the at least one driven gear; a second shifting member including at least two drive gears rotatably disposed on the third input shaft, at least two driven gears fixedly disposed on the intermediate shaft, and at least one synchronizer selectively connecting any of the at least two drive gears to the third input shaft, wherein one of the at least two drive gears is operably connected to one of the at least two driven gears through an idle gear and another of the at least two drive gears is engaged with another of the at least two driven gears; and a third shifting member receiving torque of the first shifting member or the second shifting member from the drive gear engaged with the transfer gear, selectively receiving the torque of the engine from the first input shaft, and changing and outputting the torque received from the first shifting member or the second shifting member and the torque of the engine.
[0028] The at least two drive gears of the first shifting member may include a 1/9 drive gear and a 3/7 drive gear, the at least one driven gear of the first shifting member may include a 1/9 driven gear, and the at least one synchronizer of the first shifting member may include a first synchronizer.
[0029] The 1/9 drive gear may be engaged with the 1/9 driven gear, the 3/7 drive gear may be engaged with the transfer gear, and the first synchronizer may selectively connect the 1/9 drive gear or the 3/7 drive gear to the second input shaft.
[0030] The at least two drive gears of the second shifting member may include a 2/8 drive gear, a 4/6 drive gear, and a 10/R drive gear, the at least two driven gears of the second shifting member may include a 2/8 driven gear, a 4/6 driven gear, and a 10/R driven gear, and the at least one synchronizer of the second shifting member may include second and third synchronizers.
[0031] The 2/8 drive gear may be engaged with the 2/8 driven gear, the 4/6 drive gear may be engaged with the 4/6 driven gear, the 10/R drive gear may be operably connected to the 10/R drive gear through the idle gear, the second synchronizer may selectively connect the 2/8 drive gear or the 4/6 drive gear to the third input shaft, and the third synchronizer may selectively connect the 10/R drive gear to the third input shaft.
[0032] The third shifting member may include: a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear as rotation elements thereof; a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear as rotation elements thereof; four rotation shafts directly connected to at least one rotation element among the rotation elements of the first planetary gear set and the second planetary gear set; and frictional elements, any one of the frictional elements selectively connecting any one rotation shaft among the four rotation shafts to the first input shaft and the other of the frictional elements selectively connecting another rotation shaft among the four rotation shafts to a transmission housing.
[0033] Other rotation shaft among the four rotation shafts may be directly connected to the drive gear engaged with the transfer gear.
[0034] The four rotation shafts may include: a first rotation shaft directly connected to the first sun gear and selectively connected to the transmission housing through a brake; a second rotation shaft directly connecting the first planet carrier to the second ring gear and directly connected to an output shaft; a third rotation shaft directly connecting the first ring gear to the second planet carrier and selectively connected to the first input shaft through a third clutch; and a fourth rotation shaft directly connected to the second sun gear and receiving torque from the first shifting member and the second shifting member.
[0035] The exemplary embodiment of the present disclosure may achieve one reverse speed stage and ten forward speed stages by adding two planetary gear sets to a DCT provided with three synchronizers. Therefore, multiple speed stages are achieved and fuel economy is improved.
[0036] In addition, an interior layout may be simplified, length and weight of the DCT may be minimized by reducing the number of components.
[0037] In addition, since even-numbered speed stages and odd-numbered speed stages are achieved by turns by alternately operating two clutches, smooth shift may be achieved.
[0038] Other effects obtainable or predictable from an exemplary embodiment of the present disclosure will be explicitly or implicitly described in a DETAILED DESCRIPTION section. That is, various effects predictable from an exemplary embodiment of the present disclosure will be described in the DETAILED DESCRIPTION section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a schematic diagram of a power transmission apparatus for a vehicle according to an exemplary embodiment of the present disclosure.
[0040] FIG. 2 is an operational chart of a power transmission apparatus for a vehicle according to an exemplary embodiment of the present disclosure.
[0041] FIG. 3 is a lever diagram of a power transmission apparatus for a vehicle according an exemplary embodiment of the present disclosure.
[0042] FIG. 4 is a schematic diagram of a power transmission apparatus for a vehicle according to another exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
[0043] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the disclosure 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 disclosure.
[0044] Parts which are not related with the description may be omitted for clearly describing the exemplary embodiments of the present disclosure and like reference numerals may refer to like or similar elements throughout the specification.
[0045] In the following description, dividing names of components into first, second, and the like is to divide the names because the names of the components are the same as each other and an order thereof is not particularly limited.
[0046] FIG. 1 is a schematic diagram of a power transmission apparatus for a vehicle according to the first exemplary embodiment of the present disclosure.
[0047] Referring to FIG. 1 , torque of an engine ENG that is a power source may be changed into five preliminarily shifted torques through a first shifting member T 1 and a second shifting member T 2 and the five preliminarily shifted torques may be transmitted to a third shifting member T 3 in a power transmission apparatus according to a first exemplary embodiment of the present disclosure. The five preliminarily shifted torques transmitted to the third shifting member T 3 may be changed into ten forward speed stages and one reverse speed stage, and the ten forward speed stages and the one reverse speed stage may be output.
[0048] The engine ENG that is the power source may be a gasoline engine or a diesel engine using a fossil fuel, or an electric motor.
[0049] The torque generated in the engine ENG may be transmitted to the first shifting member T 1 , the second shifting member T 2 and the third shifting member T 3 through first, second, and third input shafts IS 1 , IS 2 , and IS 3 .
[0050] The first input shaft IS 1 may be directly connected to an output side of the engine ENG and directly transmit torque of the engine ENG to the third shifting member T 3 .
[0051] The second input shaft IS 2 may be a hollow shaft, enclose the first input shaft IS 1 without rotational interference therewith, may be selectively connected to the output side of the engine ENG through a first clutch CL 1 , and selectively transmit the torque of the engine ENG to the first shifting member T 1 .
[0052] The third input shaft IS 3 may be a hollow shaft, enclose the second input shaft IS 2 without rotational interference therewith, may be selectively connected to the output side of the engine ENG through a second clutch CL 2 , and selectively transmit the torque of the engine ENG to the second shifting member T 2 .
[0053] The first shifting member T 1 may include a 1/9 drive gear D 1 / 9 , a 3/7 drive gear D 3 / 7 , a first synchronizer SL 1 disposed on the second input shaft IS 2 , and a 1/9 driven gear P 1 / 9 fixedly disposed on an intermediate shaft CS disposed in parallel with the second input shaft IS 2 and engaged with the 1/9 drive gear D 1 / 9 .
[0054] The 1/9 drive gear D 1 / 9 and the 3/7 drive gear D 3 / 7 may be rotatably disposed on the second input shaft IS 2 , and the first synchronizer SL 1 may operably connect the 1/9 drive gear D 1 / 9 or the 3/7 drive gear D 3 / 7 to the second input shaft IS 2 selectively.
[0055] In addition, a transfer gear TFG engaged with the 3/7 drive gear D 3 / 7 may be fixedly disposed on a rear portion of the intermediate shaft CS.
[0056] The first synchronizer SL 1 may operably connect the 1/9 drive gear D 1 / 9 or the 3/7 drive gear D 3 / 7 to the second input shaft IS 2 selectively. Therefore, the torque of the engine ENG may be transmitted to the third shifting member T 3 through the 3/7 drive gear D 3 / 7 without rotation speed change, or may be transmitted to the intermediate shaft CS through the first synchronizer SL 1 and the 1/9 drive gear D 1 / 9 and may then be transmitted to the third shifting member T 3 through the 3/7 drive gear D 3 / 7 engaged with the transfer gear TFG with the rotation speed being changed.
[0057] Therefore, a first preliminarily shifted torque for achieving a first forward speed stage and a ninth forward speed stage, and a second preliminarily shifted torque for achieving a third forward speed stage and a seventh forward speed stage may be generated in the first shifting member T 1 . Herein, the second preliminarily shifted torque may be the same as a rotation speed of the engine ENG.
[0058] The transfer gear TFG engaged with the 3/7 drive gear D 3 / 7 fixedly disposed on the intermediate shaft CS may transmit torque transmitted from the first shifting member T 1 and the second shifting member T 2 to the third shifting member T 3 through the 3/7 drive gear D 3 / 7 .
[0059] In addition, the 3/7 drive gear D 3 / 7 may transmit torque of the intermediate shaft CS to the third shifting member T 3 without rotation speed change, or may change rotation speed of the intermediate shaft CS according to gear ratios of the transfer gear TFG and the 3/7 drive gear D 3 / 7 engaged with each other and transmit the changed rotation speed to the third shifting member T 3 .
[0060] The second shifting member T 2 may include a 2/8 drive gear D 2 / 8 fixedly disposed on the third input shaft IS 3 , a 4/6 drive gear D 4 / 6 fixedly disposed on the third input shaft IS 3 , a 10/R drive gear D 10 /R fixedly disposed on the third input shaft IS 3 , a 2/8 driven gear P 2 / 8 engaged with the 2/8 drive gear D 2 / 8 , a 4/6 driven gear P 4 / 6 engaged with the 4/6 drive gear D 4 / 6 , a second synchronizer SL 2 disposed on the intermediate shaft CS, a 10/R driven gear P 10 /R operably connected to the 10/R drive gear D 10 /R, a third synchronizer SL 3 disposed on the intermediate shaft CS, an idle gear IDG engaged with the 10/R drive gear D 10 /R and the 10/R driven gear P 10 /R.
[0061] The 2/8 driven gear P 2 / 8 and the 4/6 driven gear P 4 / 6 may be rotatably disposed on the intermediate shaft CS, and the second synchronizer SL 2 may operably connect the 2/8 driven gear P 2 / 8 or the 4/6 driven gear P 4 / 6 to the intermediate shaft CS selectively. In addition, the 10/R driven gear P 10 /R may be rotatably disposed on the intermediate shaft CS, and the third synchronizer SL 3 may operably connect the 10/R driven gear P 10 /R to the intermediate shaft CS selectively.
[0062] The idle gear IDG may be disposed on an idle shaft IDS and cause the 10/R driven gear P 10 /R and the 10/R drive gear D 10 /R to rotate in the same direction.
[0063] Therefore, a third preliminarily shifted torque for achieving a second forward speed stage and an eighth forward speed stage, a fourth preliminarily shifted torque for achieving a fourth forward speed stage and a sixth forward speed stage, and a fifth preliminarily shifted torque for achieving a tenth forward speed stage and a reverse speed stage may be generated in the second shifting member T 2 . The fifth preliminarily shifted torque may be, or produce, an inverse rotation speed.
[0064] The third shifting member T 3 may include first and second planetary gear sets PG 1 and PG 2 , one clutch CL 3 and one brake BK.
[0065] The first planetary gear set PG 1 may be a single pinion planetary gear set and may include a first sun gear S 1 , a first planet carrier PC 1 rotatably supporting a first pinion P 1 that is externally meshed with the first sun gear S 1 , and a first ring gear R 1 that is internally meshed with the first pinion P 1 as rotation elements thereof.
[0066] The second planetary gear set PG 2 may be a single pinion planetary gear set and may include a second sun gear S 2 , a second planet carrier PC 2 rotatably supporting a second pinion P 2 that is externally meshed with the second sun gear S 2 , and a second ring gear R 2 that is internally meshed with the second pinion P 2 as rotation elements thereof.
[0067] Since the first planet carrier PC 1 may be directly connected to the second ring gear R 2 and the first ring gear R 1 may be directly connected to the second planet carrier PC 2 , the first and second planetary gear sets PG 1 and PG 2 may include four rotation shafts TM 1 to TM 4 .
[0068] The four rotation shafts TM 1 to TM 4 will be described in detail below.
[0069] The first rotation shaft TM 1 may be directly connected to the first sun gear S 1 and may be selectively connected to a transmission housing H so as to be operated as a selective fixed element.
[0070] The second rotation shaft TM 2 may directly connect the first planet carrier PC 1 with the second ring gear R 2 and may be directly connected to the output shaft OS so as to be operated as an output element continuously.
[0071] The third rotation shaft TM 3 may directly connect the first ring gear R 1 with the second planet carrier PC 2 and may be selectively connected to the first input shaft IS 1 so as to be operated as a selective input element.
[0072] The fourth rotation shaft TM 4 may be directly connected to the second sun gear S 2 and may be directly connected to the 3/7 drive gear D 3 / 7 of the first shifting member T 1 .
[0073] The first ring gear R 1 and the second planet carrier PC 2 directly connected to the third rotation shaft TM 3 may be selectively connected to the first input shaft IS 1 through the third clutch CL 3 , and the first sun gear S 1 directly connected to the first rotation shaft TM 1 may be selectively connected to the transmission housing H through a brake BK.
[0074] The output shaft OS directly connected to the second rotation shaft TM 2 may transmit torque output from the third shifting member T 3 to a final speed reduction unit of a differential apparatus (not shown).
[0075] Since the first, second, and third synchronizers SL 1 , SL 2 , and SL 3 may be well known to a person of an ordinary skill in the art, a detailed description thereof will be omitted. In addition, first, second, and third sleeves SLE 1 , SLE 2 , and SLE 3 applied respectively to the first, second, and third synchronizers SL 1 , SL 2 , and SL 3 , as may be also well known to a person of an ordinary skill in the art, are operated by additional actuators (not shown) and the actuators may be controlled by a transmission control unit.
[0076] FIG. 2 is an operational chart of a power transmission apparatus for a vehicle according to an exemplary embodiment of the present disclosure, and FIG. 3 is a lever diagram of a power transmission apparatus for a vehicle according to an exemplary embodiment of the present disclosure. Referring to FIG. 2 and FIG. 3 , shifting processes of the power transmission apparatus will be described in detail below.
[0077] The third clutch CL 3 may not be operated and torque input to the fourth rotation shaft TM 4 may be operated as input torque at the first to the fourth forward speed stages and the reverse speed stage. On the contrary, the third clutch CL 3 may be operated and torque input to the fourth rotation shaft TM 4 and the third rotation shaft TM 3 may be operated as input torque at the sixth to the tenth forward speed stages. In addition, since the third clutch CL 3 may be operated but any synchronizer may not be operated at the fifth forward speed stage, torque input to the third rotation shaft TM 3 may be operated as input torque.
[Reverse Speed Stage]
[0078] As shown in FIG. 2 , the 10/R driven gear P 10 /R may be operably connected to the intermediate shaft CS through the sleeve SLE 3 of the third synchronizer SL 3 , and the second clutch CL 2 and the brake BK may be operated at the reverse speed stage REV.
[0079] Therefore, the torque of the engine ENG may be shifted into the fifth preliminarily shifted torque through the second clutch CL 2 , the third input shaft IS 3 , the 10/R drive gear D 10 /R, the idle gear IDG, the 10/R driven gear P 10 /R, the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the fifth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 as the inverse rotation speed.
[0080] As shown in FIG. 3 , since the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK in a state that the fifth preliminarily shifted torque is input to the fourth rotation shaft TM 4 , a reverse shift line SR may be formed in the third shifting member T 3 . Therefore, a gear ratio of REV may be output through the second rotation shaft TM 2 that is the output member.
[First Forward Speed Stage]
[0081] As shown in FIG. 2 , the 1/9 drive gear D 1 / 9 may be operably connected to the second input shaft IS 2 through the sleeve SLE 1 of the first synchronizer SL 1 , and the first clutch CL 1 and the brake BK may be operated at the first forward speed stage D/ 1 .
[0082] Therefore, the torque of the engine ENG may be shifted into the first preliminarily shifted torque through the first clutch CL 1 , the second input shaft IS 2 , the 1/9 drive gear D 1 / 9 , the 1/9 driven gear P 1 / 9 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the first preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0083] As shown in FIG. 3 , since the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK in a state that the first preliminarily shifted torque is input to the fourth rotation shaft TM 4 , a first shift line SP 1 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 1 may be output through the second rotation shaft TM 2 that is the output member.
[Second Forward Speed Stage]
[0084] As shown in FIG. 2 , the 2/8 driven gear P 2 / 8 may be operably connected to the intermediate shaft CS through the sleeve SLE 2 of the second synchronizer SL 2 , and the second clutch CL 2 and the brake BK may be operated at the second forward speed stage D 2 .
[0085] Therefore, the torque of the engine ENG may be shifted into the third preliminarily shifted torque through the second clutch CL 2 , the third input shaft IS 3 , the 2/8 drive gear D 2 / 8 , the 2/8 driven gear P 2 / 8 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the third preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0086] As shown in FIG. 3 , since the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK in a state that the third preliminarily shifted torque is input to the fourth rotation shaft TM 4 , a second shift line SP 2 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 2 may be output through the second rotation shaft TM 2 that is the output member.
[Third Forward Speed Stage]
[0087] As shown in FIG. 2 , the 3/7 drive gear D 3 / 7 may be operably connected to the second input shaft IS 2 through the sleeve SLE 1 of the first synchronizer SL 1 , and the first clutch CL 1 and the brake BK may be operated at the third forward speed stage D 3 .
[0088] Therefore, the torque of the engine ENG may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 as the second preliminarily shifted torque through the first clutch CL 1 , the second input shaft IS 2 , and the 3/7 drive gear D 3 / 7 .
[0089] As shown in FIG. 3 , since the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK in a state that the second preliminarily shifted torque is input to the fourth rotation shaft TM 4 , a third shift line SP 3 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 3 may be output through the second rotation shaft TM 2 that is the output member.
[Fourth Forward Speed Stage]
[0090] As shown in FIG. 2 , the 4/6 driven gear P 4 / 6 may be operably connected to the intermediate shaft CS through the sleeve SLE 2 of the second synchronizer SL 2 , and the second clutch CL 2 and the brake BK may be operated at the fourth forward speed stage D 4 .
[0091] Therefore, the torque of the engine ENG may be shifted into the fourth preliminarily shifted torque through the second clutch CL 2 , the third input shaft IS 3 , the 4/6 drive gear D 4 / 6 , the 4/6 driven gear P 4 / 6 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the fourth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0092] As shown in FIG. 3 , since the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK in a state that the fourth preliminarily shifted torque is input to the fourth rotation shaft TM 4 , a fourth shift line SP 4 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 4 may be output through the second rotation shaft TM 2 that is the output member.
[Fifth Forward Speed Stage]
[0093] As shown in FIG. 2 , the first, second, and third synchronizers SL 1 , SL 2 , and SL 3 may maintain neutral states, and the third clutch CL 3 and the brake BK may be operated at the fifth forward speed stage D 5 .
[0094] Therefore, since the torque of the engine ENG may be input to the third rotation shaft TM 3 through the first input shaft IS 1 and the first rotation shaft TM 1 may be operated as the fixed element by operation of the brake BK, a fifth shift line SP 5 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 5 may be output through the second rotation shaft TM 2 that is the output member.
[Sixth Forward Speed Stage]
[0095] As shown in FIG. 2 , the 4/6 driven gear P 4 / 6 may be operably connected to the intermediate shaft CS through the sleeve SLE 2 of the second synchronizer SL 2 , and the second and third clutches CL 2 and CL 3 may be operated at the sixth forward speed stage D 6 .
[0096] Therefore, the torque of the engine ENG may be shifted into the fourth preliminarily shifted torque through the third input shaft IS 3 , the 4/6 drive gear D 4 / 6 , the 4/6 driven gear P 4 / 6 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 by operation of the second clutch CL 2 , and the fourth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0097] In addition, the torque of the engine ENG may be input to the third rotation shaft TM 3 of the third shifting member T 3 through the first input shaft IS 1 by operation of the third clutch CL 3 .
[0098] As shown in FIG. 3 , since the torque of the engine ENG may be input to the third rotation shaft TM 3 and the fourth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 , a sixth shift line SP 6 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 6 may be output through the second rotation shaft TM 2 that is the output member.
[Seventh Forward Speed Stage]
[0099] As shown in FIG. 2 , the 3/7 drive gear D 3 / 7 may be operably connected to the second input shaft IS 2 through the sleeve SLE 1 of the first synchronizer SL 1 , and the first and third clutches CL 1 and CL 3 may be operated at the seventh forward speed stage D 7 .
[0100] Therefore, the torque of the engine ENG may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 as the second preliminarily shifted torque through the first clutch CL 1 , the second input shaft IS 2 , and the 3/7 drive gear D 3 / 7 .
[0101] In addition, the torque of the engine ENG may be input to the third rotation shaft TM 3 of the third shifting member T 3 through the first input shaft IS 1 by operation of the third clutch CL 3 .
[0102] As shown in FIG. 3 , since the torque of the engine ENG may be input to the third rotation shaft TM 3 and the second preliminarily shifted torque may be input to the fourth rotation shaft TM 4 , the first and second planetary gear sets PG 1 and PG 2 may be integrally rotated and a seventh shift line SP 7 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 7 may be output through the second rotation shaft TM 2 that is the output member.
[Eighth Forward Speed Stage]
[0103] As shown in FIG. 2 , the 2/8 driven gear P 2 / 8 may be operably connected to the intermediate shaft CS through the sleeve SLE 2 of the second synchronizer SL 2 , and the second and third clutches CL 2 and CL 3 may be operated at the eighth forward speed stage D 8 .
[0104] Therefore, the torque of the engine ENG may be shifted into the third preliminarily shifted torque through the second clutch CL 2 , the third input shaft IS 3 , the 2/8 drive gear D 2 / 8 , the 2/8 driven gear P 2 / 8 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the third preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0105] In addition, the torque of the engine ENG may be input to the third rotation shaft TM 3 of the third shifting member T 3 by operation of the third clutch CL 3 .
[0106] As shown in FIG. 3 , since the torque of the engine ENG may be input to the third rotation shaft TM 3 and the third preliminarily shifted torque may be input to the fourth rotation shaft TM 4 , an eighth shift line SP 8 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 8 may be output through the second rotation shaft TM 2 that is the output member.
[Ninth Forward Speed Stage]
[0107] As shown in FIG. 2 , the 1/9 drive gear D 1 / 9 may be operably connected to the second input shaft IS 2 through the sleeve SLE 1 of the first synchronizer SL 1 , and the first and third clutches CL 1 and CL 3 may be operated at the ninth forward speed stage D 9 .
[0108] Therefore, the torque of the engine ENG may be shifted into the first preliminarily shifted torque through the first clutch CL 1 , the second input shaft IS 2 , the 1/9 drive gear D 1 / 9 , the 1/9 driven gear P 1 / 9 , the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the first preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 .
[0109] In addition, the torque of the engine ENG may be input to the third rotation shaft TM 3 of the third shifting member T 3 through the first input shaft IS 1 by operation of the third clutch CL 3 .
[0110] As shown in FIG. 3 , since the torque of the engine ENG may be input to the third rotation shaft TM 3 and the first preliminarily shifted torque may be input to the fourth rotation shaft TM 4 , a ninth shift line SP 9 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 9 may be output through the second rotation shaft TM 2 that is the output member.
[Tenth Forward Speed Stage]
[0111] As shown in FIG. 2 , the 10/R driven gear P 10 /R may be operably connected to the intermediate shaft CS through the sleeve SLE 3 of the third synchronizer SL 3 , and the second and third clutches CL 2 and CL 3 may be operated at the tenth forward speed stage D 10 .
[0112] Therefore, the torque of the engine ENG may be shifted into the fifth preliminarily shifted torque through the second clutch CL 2 , the third input shaft IS 3 , the 10/R drive gear D 10 /R, the idle gear IDG, the 10/R driven gear P 10 /R, the intermediate shaft CS, the transfer gear TFG, and the 3/7 drive gear D 3 / 7 , and the fifth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 of the third shifting member T 3 as an inverse rotation speed.
[0113] In addition, the torque of the engine ENG may be input to the third rotation shaft TM 3 of the third shifting member T 3 through the first input shaft IS 1 by operation of the third clutch CL 3 .
[0114] As shown in FIG. 3 , since the torque of the engine ENG may be input to the third rotation shaft TM 3 and the fifth preliminarily shifted torque may be input to the fourth rotation shaft TM 4 , a tenth shift line SP 10 may be formed in the third shifting member T 3 . Therefore, a gear ratio of D 10 may be output through the second rotation shaft TM 2 that is the output member.
[0115] The power transmission apparatus for a vehicle according to a first exemplary embodiment of the present disclosure may achieve the reverse speed stage and ten forward speed stage by adding two planetary gear sets to a DCT provided with three synchronizers. Therefore, multiple speed stages may be achieved and fuel economy may be improved.
[0116] In addition, an interior layout may be simplified, and a length and weight of the DCT may be minimized by reducing the number of components.
[0117] In addition, since even-numbered speed stages and odd-numbered speed stages are achieved in turns by alternately operating two clutches, smooth shifting may be achieved.
[0118] FIG. 4 is a schematic diagram of a power transmission apparatus for a vehicle according to another exemplary embodiment of the present disclosure.
[0119] Referring to FIG. 4 , the second and third synchronizers SL 2 and SL 3 included in the second shifting member T 2 may be disposed on the intermediate shaft CS in the power transmission apparatus for a vehicle according to a first exemplary embodiment of the present disclosure, but the second and third synchronizers SL 2 and SL 3 may be disposed on the third input shaft IS 3 according to a second exemplary embodiment.
[0120] Therefore, the 2/8 drive gear D 2 / 8 and the 4/6 drive gear D 4 / 6 may be rotatably disposed on the third input shaft IS 3 , and the second synchronizer SL 2 operably may connect the 2/8 drive gear D 2 / 8 or the 4/6 drive gear D 4 / 6 to the third input shaft IS 3 selectively. In addition, the 2/8 driven gear P 2 / 8 engaged with the 2/8 drive gear D 2 / 8 and the 4/6 driven gear P 4 / 6 engaged with the 4/6 drive gear D 4 / 6 may be fixedly disposed on the intermediate shaft CS.
[0121] Further, the 10/R drive gear D 10 /R may be rotatably disposed on the third input shaft IS 3 and the third synchronizer SL 3 may operably connect the 10/R drive gear D 10 /R to the third input shaft IS 3 selectively. In addition, the 10/R driven gear P 10 /R engaged with the 10/R drive gear D 10 /R may be fixedly disposed on the intermediate shaft CS.
[0122] The constituent elements and shifting processes according to a second exemplary embodiment of the present disclosure may be the same as those according to a first exemplary embodiment except for arrangements of the second and third synchronizers SL 2 and SL 3 and the drive gears and the driven gears related thereto. Therefore, detailed description thereof will be omitted.
[0123] While this disclosure has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the disclosure 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.
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A power transmission apparatus for a vehicle includes a first input shaft directly connected to an engine, a second input shaft enclosing the first input shaft and rotating independently from the first input shaft and selectively receiving torque of the engine through a first clutch, a third input shaft enclosing the second input shaft and rotating independently from with the second input shaft and selectively receiving the torque of the engine through a second clutch, an intermediate shaft disposed in parallel with the first, second and third input shafts, a transfer gear fixedly disposed on the intermediate shaft and outputting torque of the intermediate shaft, a first shifting member, a second shifting member, and a third shifting member for changing the torque of the engine.
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FIELD
[0001] This application relates generally to farming equipment. More particularly, this application relates to a truck or trailer bed having a side loading panel for loading and transporting harvested fruits and vegetables from the field.
BACKGROUND
[0002] Modern harvesting equipment is essential is efficient farming. Specialized harvesting equipment allows for minimum labor in harvesting large amounts of crops. With potatoes, onions, beets, and other root vegetables, harvesters dig into the ground and separate the vegetables from the greens and the dirt through a series of belts. The harvesters then load the harvested vegetables into vegetable trucks, which are filled as they drive along next to the harvester. Some vegetable trucks are trailers for semi-tractors and others are special beds on heavy trucks.
[0003] Fruit and vegetable hauling trucks and trailers usually have a side that swings out on a hinge and drops down to allow the harvester to position a loading boom close over the truck and close enough to the bottom of the payload floor to limit damage to the harvested crop as they are loaded into the bed. As the as the bed is filled, the loading boom rises as the level of the vegetables in the truck rises and the drop side is eventually raised to allow the entire bed to be filled.
[0004] Current drop sides are often raised and lowered by swinging a side panel down around a hinge at the bottom of the panel using an automatic actuator. The drop sides can sometimes hit the loading boom when being raised, which can damage the drop panel or the automatic actuator and mechanisms for opening and closing the panel, or the loading boom and its components. Such side panels also require a relatively long boom to allow enough room for the door to swing shut, and a careful distance management between the harvester and the hauling bed. Additionally, the side panel sometimes damages some of the vegetables by pinching them in the hinged section. The hinged drop panels also require a long loading boom to allow the truck to travel to the side of the harvester without the panel striking the harvester or the boom when being lowered and raised.
SUMMARY
[0005] A vehicle may be provided with a crop hauling bed. The bed may include a frame configured to be mounted to the chassis of a vehicle or trailer (the frame supporting body panels which provide a volume suitable for holding harvested crops), a door opening along a side edge of the frame, a door coupled to the frame such that the door is selectively and slidably openable and closable to cover the door opening, and at least one actuator configured to slidably move the door between an open position and a closed position. The bed may also include a slide mechanism slidably coupling the door to the frame.
[0006] In some embodiments, the slide mechanism may include pins and slots. The pins may extend from the door and the slots may be formed in the frame or vice-versa. In some embodiments, the at least one actuator may be a linear actuator such as a hydraulic cylinder, screw jack, pneumatic cylinder, chain and pulley with an electric motor, etc. The at least one actuator may be powered by a vehicle coupled to the bed, and may be controlled from the cab of the vehicle. The door may also include a layer configured to reduce damage to harvested crops.
[0007] Loading crops in the crop hauling bed may be accomplished by providing a harvester to harvest a crop and deliver it to a vehicle with a crop hauling bed having a loading door. The loading door may be slidably lowered from a closed position to an open position on the crop hauling bed using actuators. The harvested crops may then be loaded into to crop hauling bed, and the loading door slidably raised on the crop hauling bed to a closed position as the crop hauling bed fills with harvested crops.
[0008] These and other aspects of the present invention will become more fully apparent from the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The following description can be better understood in light of Figures, in which:
[0010] FIG. 1 a is a perspective view of an exemplary embodiment of a loading door on crop hauling bed in an open position;
[0011] FIG. 1 b is a perspective view of an exemplary embodiment of a loading door on crop hauling bed in a closed position;
[0012] FIGS. 2 a -2 b are detailed views of a slide mechanism an exemplary embodiment of a loading door on crop hauling bed;
[0013] FIGS. 3 a -3 b illustrate a door panel accommodation of an exemplary embodiment of a loading door on crop hauling bed in an open and closed position; and
[0014] FIGS. 4 a -4 b illustrate an actuator mechanism of an exemplary embodiment of a loading door on crop hauling bed in an open and closed position.
[0015] Together with the following description, the Figures demonstrate and explain the principles of loading doors on hauling beds and associated methods. In the Figures, the size and relative placement of components and regions of illustrated devices may be exaggerated or modified for clarity. The same reference numerals in different drawings represent the same element, and thus their descriptions may not be repeated. Some drawings may omit certain components not necessary for describing the illustrated embodiments, but which would be known to those of ordinary skill in the art to be present in hauling beds.
DETAILED DESCRIPTION
[0016] As in the illustrated embodiments, aspects and features of exemplary loading doors on crop hauling beds and associated methods of making and using such doors are disclosed and described below. The following description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the apparatus and associated methods of using the apparatus can be implemented and used without employing these specific details. Indeed, the devices and associated methods can be placed into practice by modifying the illustrated devices and associated methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry. For example, while this description focuses on loading doors on crop hauling bed attached to a truck chassis, embodiments employing the principles described herein may be used on or with trailers, or other load-hauling machinery, mechanisms, vehicles, devices, etc. without departing from the scope of the devices described herein.
[0017] FIGS. 1 a -4 b illustrate various features of a produce hauling bed 20 on a truck chassis 10 . The hauling bed 20 may include a loading door 100 . Loading door 100 and hauling bed 20 may include slide mechanism 130 to slidably attach loading door 100 to truck chassis 10 , and actuators 160 to move loading door 100 between a closed ( FIG. 1 a ) and an open ( FIG. 1 b ) position.
[0018] Loading door 100 may open and close by sliding a top portion 112 vertically until loading door 100 is in a closed position where a bottom portion 114 engages with a lower lip 24 of a door frame in hauling bed 20 , thereby providing additional volume within hauling bed 20 . Loading door 100 may be gradually raised as hauling bed 20 is filled to provide a continuous short drop for harvested produce, reducing the amount of loss from bruising. Additionally, the generally vertical closing motion of loading door 100 may provide less risk of damage to loading door 100 and to a harvester depositing into hauling bed 20 .
[0019] Generally, traditional hauling beds usually have a loading door that swings out and drops down around a hinge to allow the harvester to position a loading boom close over the truck and close enough to the bottom of the payload floor to limit damage to the harvested crop as they are loaded into the bed. Current drop sides are often raised and lowered by swinging a side panel down around a hinge at the bottom of the panel using an automatic actuator. The drop sides can sometimes hit the loading boom when being raised, which can damage the drop panel or the automatic actuator and mechanisms for opening and closing the panel, or the loading boom and its components. Such side panels also require a relatively long boom to allow enough room for the door to swing shut, and a careful distance management between the harvester and the hauling bed. Additionally, the side panel sometimes damages some of the harvested crops by pinching them in the hinged section. The hinged drop panels also require a long loading boom to allow the truck to travel to the side of the harvester without the panel striking the harvester or the boom when being lowered and raised.
[0020] In contrast to traditional hauling beds, the present embodiments of exemplary loading doors 100 , including those illustrated in FIGS. 1 a -4 b , slide up into a closed position ( FIGS. 1 b , 2 b , 3 b , 4 b ) using actuators 160 thereby eliminating the room required for the traditional outwardly swinging loading doors, and minimizing potential damage to harvester booms and the loading door 100 . Additionally, the sliding action of loading doors 100 may reduce produce damaged by traditionally closing hinged doors that would crush loaded produce in the hinge intersection.
[0021] As best shown in FIGS. 2 a -2 b , 4 a -4 b , slide mechanisms 130 , 140 may include pins 134 , 144 , slidably engaged in slots 132 , 142 . As shown in FIGS. 2 a -2 b , slot 132 is formed in frame member 26 , which forms an edge of an opening for loading door 100 . Pin 134 may be located on an edge of loading panel 110 close to top 112 of loading door 100 such that when pin 134 slides in slot 132 , top 112 generally moves vertically to open/shut loading door 100 . As top 112 moves up, bottom 114 follows the contour of the bed 20 until bottom 114 engages with frame edge 24 , indicating a fully closed loading door 100 , as shown in FIGS. 1 b , 2 b , 3 b , 4 b . When closing loading door 100 with harvested produce in the bed bottom 114 slides out from under the loaded produce with low risk of damage to the loaded produce.
[0022] Actuators 160 may be used to push loading door 100 open. Actuators 160 may be attached to bracket 111 on upper portion 110 of loading door 100 and to chassis 10 or bed 20 , such that when actuator 160 is activated, loading door 100 moves between the open and closed positions, or vice versa. Actuators 160 may be hydraulic cylinders controlled with a hydraulic system of chassis 10 , or may be any actuator capable of moving loading door between closed and open positions. In some embodiments, actuators may of any suitable type and controlled using vehicle hydraulic, pneumatic, or electrical systems.
[0023] The various components of loading door 100 and bed 20 may be formed of steel, aluminum, or any suitable material or alloy used in the construction of such items. In some embodiments, the inside of hauling bed 20 , including an inside surface of loading door 100 , may be lined with plastic layer, such as HDPE, PTFE or may be treated with a surface treatment to facilitate protection or movement of loaded produce in hauling bed 20 , including offload through door 22 as shown in FIGS. 3 a -3 b . In some embodiments, pins 134 , 144 may include bearings or bushings, or other similar device, to reduce wear between slot 132 , 142 and pins 132 , 142 .
[0024] In some embodiments, slot 132 may be through two sides a hollow tube frame member 26 , or may be through only one side such that the pin movement is hidden within the frame member, with a similar arrangement for slot 142 and its corresponding frame member. In other embodiments, frame member 26 may be a solid piece with a channel or a slot to cooperate with pin 134 . Similarly, the slots may be provided in a portion of door 100 and the pins may be provided extending from frame member 26 . In some embodiments, doors consistent with this description may be retrofitted onto existing beds by replacing a section of the bed walls or by replacing the traditionally outward swinging door.
[0025] Similarly, in some embodiments, the actuators 160 may be a single actuator located near the center of the door, or the actuators may be positioned at the very edges of door 100 close to the slide mechanisms 130 , 140 .
[0026] In addition to any previously indicated modification, numerous other variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of this description, and appended claims are intended to cover such modifications and arrangements. Thus, while the information has been described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred aspects, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, form, function, manner of operation and use may be made without departing from the principles and concepts set forth herein. Also, as used herein, examples are meant to be illustrative only and should not be construed to be limiting in any manner.
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A vehicle may be provided with a crop hauling bed. The bed may include a frame configured to be mounted to the chassis of a vehicle or trailer (the frame supporting body panels which provide a volume suitable for holding harvested crops), a door opening along a side edge of the frame, a door coupled to the frame such that the door is selectively and slidably openable and closable to cover the door opening, and at least one actuator configured to slidably move the door between an open position and a closed position. The bed may also include a slide mechanism slidably coupling the door to the frame.
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BACKGROUND OF THE INVENTION
1. Field Of The Invention
The invention herein pertains to a suction tool for plumbers or others to be used for installing basket strainers, food disposals and other plumbing assemblies wherein a first component of the assembly is held stationary against one surface of a barrier such as an inner sink basin while a second component of the assembly is connected to the first through the opposite surface of the barrier, such as against the underneath surface of the sink.
2. Description Of The Prior Art And Objectives Of The Invention
The installation of flanged members such as sink traps, disposal ports and the like have long caused concern for plumbers and servicemen who must firmly hold components on opposite surfaces of sinks, walls or the like during installation and assembly In past years installation and service work on food disposals under kitchen sinks has generally required the use of a plumber and a helper to adequately complete the required work. The helper would hold the disposal trap flange along the inner (upper) sink surface proximate the opening in the kitchen sink while the plumber, by working underneath, would attach a pipe, food disposal or other components to the held disposal trap. However, in recent years with the cost of labor ever increasing, many plumbers now prefer, and in some cases must work alone, although many jobs need an extra "hand" from time to time to stabilize or to reach a component or part as they work through an opposite barrier surface. Oftentimes a lone plumber will install a food disposal by working mainly underneath the sink, only to realize when arising that the previously positioned top-side trap flange has shifted somewhat, requiring the disposal be disconnected and reset, much to the chagrin of the installer.
Thus, with the disadvantages and problems associated with prior art tools and methods available, the present invention was conceived and one of its objectives is to provide a unique tool which will assist a plumber in working alone when installing basket strainers, food disposals or other assemblies and components that are connected through an inconvenient to reach-around barrier wall.
It is yet another objective of the present invention to provide a tool for assisting in installing various plumbing components which will temporarily maintain a component in a steady, fixed manner until fully set.
It is still another objective of the present invention to provide a tool which includes a suction cup and pressure plate for retaining a plumbing component in an immovable posture such as along the inner or top surface of a conventional kitchen sink and which can easily be removed from the component when the work is completed.
It is yet another objective of the present invention to provide a suction tool for use by plumbers or others which is relatively easy to learn to use, long lasting and which is inexpensive to purchase.
Numerous other objectives and advantages of the present invention become apparent to those skilled in the art as a more detailed description is presented below.
SUMMARY OF THE INVENTION
The aforesaid and other objectives are realized by providing a tool which produces a suction force to hold a plumbing component against a sink bottom or the like which may have various embodiments, each consisting of a rigid pressure plate or disk which is connected to a suction cup. In one embodiment a longitudinal member has suction cups at each end which securely attaches the tool to the bottom of a sink or other barrier surface. The pressure plate is affixed to the bottom end of a transverse member which is slidably received perpendicularly within the longitudinal member. By manually urging the transverse member downwardly where it is held by a pawl, the pressure plate presses against the flange of a basket strainer to temporarily hold the flange in place. A plumber can then attach pipes or other components to the strainer by working beneath the sink to permanently secure the strainer in place. Thereafter, by relieving the suction force created by the tool, the tool can be removed from the basket strainer with the strainer correctly installed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a side view of the suction tool which may be used in conventional kitchen sinks for releasably, temporarily holding basket strainers or the like therein;
FIG. 2 shows a bottom view of the embodiment of the tool as shown in FIG. 1;
FIG. 3 demonstrates a top view of the tool as seen in FIG. 1;
FIG. 4 pictures a cross-sectional view along the front of a conventional sink with a second embodiment of the tool as shown in FIG. 1 used to secure a food disposal trap within the sink;
FIG. 5 depicts in exploded fashion the assembly components of a conventional food disposal in which the disposal trap is installed from above the sink whereas the remaining components are installed beneath the sink;
FIG. 6 illustrates a conventional basket strainer having certain components installed above and other components which are installed below the sink;
FIG. 7 demonstrates yet another embodiment of the tool in which a suction cup is provided with a central pressure plate having a strainer insert joined thereto as seen in side cross-sectional view; and
FIG. 8 demonstrates the tool of FIG. 7 shown in a bottom plan view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred form of the invention is shown in FIG. 1 whereby a pair of suction cups are joined at opposite ends to a longitudinal member. The longitudinal member defines a vertical slot approximately mid-way therealong through which a transverse member is slidably positioned perpendicularly to the longitudinal member. A pressure plate in circular form is affixed at the distal end of the transverse member and a strainer insert is attached to the underneath surface of the pressure plate for retaining a conventional basket strainer. On the upper end of the transverse member is situated a knob for applying manual force to the notched transverse member and a pivotal pawl is mounted on the longitudinal member, near the slot for "locking" the transverse member in position relative to the longitudinal member for maintaining pressure on the basket strainer or the like during installation.
DETAILED DESCRIPTION OF THE DRAWINGS AND OPERATION OF THE INVENTION
For a more complete understanding of the invention and its method of use, turning now to the drawings, FIG. 1 demonstrates plumbing tool 10 which consists of longitudinal member 11 having means
providing a suction in the form of suction cups 12, 12'. Longitudinal member 11 includes a slot 13 through which transverse member 14 slides. Transverse member 14 is notched and includes a series of teeth 15 along one side thereof. Pawl 16 is pivotally attached at 17 to longitudinal member 11. Pressure member 18 as seen in FIG. 1 consists of a rigid, circular metal plate which is affixed at the distal end 19 of transverse member 14. At the proximal end 20 of transverse member 14, a rounded knob 21 for applying manual pressure thereto is seen. As would be understood, pawl 16 which is spring-loaded, allows transverse member 14 to pass through longitudinal member 11 and locks member 14 into place as pawl 16 engages teeth 15 therealong. In the bottom view of tool 10 in FIG. 2, strainer insert 22 is shown. The top view of tool 10 as shown in FIG. 3 demonstrates the configuration thereof in another perspective, and as would be understood, tool 10 may have various parts formed from plastic, metal or other materials as suitably appropriate.
In FIG. 4 plumbing tool 30 is shown which is substantially similar to plumbing tool 10 of FIG. 1 with the exception that tool 30 does not include strainer insert 22, as would be needed for basket strainer installations. FIG. 4 depicts tool 30 affixed to sink 32 by suction force generated by suction cups 31, 31' along the upper inside surface 37 of sink 32, and illustrated in cross-sectional view. Transverse member 33 is in a locked downwardly position whereby pressure member 34 applies pressure to food disposal trap flange 35.
As further seen in FIG. 5, food disposal 39 consists of a series of assembly components including food disposal trap 36 having flange 35 thereon. As would also be noted, food disposal trap 36 is positioned along the inner surface 37 (FIG. 4) of sink 32. Other assembly components as seen in FIG. 5 include rubber gasket 38, fiber gasket 40, metal flanged member 41, threaded member 42, snap ring 43, and power unit 44 which are all assembled beneath sink 32, against bottom sink surface 45 (FIG. 4).
Another series of assembly components are depicted in FIG. 6 whereby basket strainer assembly 50 is shown with basket strainer 51 placed along the top or upper surface of a sink. As further illustrated in exploded fashion in FIG. 6, basket strainer 51 is held in place by rubber gasket 52, fiber gasket 53 and metal lock ring 54 which are attached to basket strainer 51 from beneath the sink.
As pictured in cross-sectional view, tool 60 in FIG. 7, comprises a single means for developing suction by use of suction cup 61 attached at its uppermost end to handle 62. Suction cup 61 is formed from conventional polymeric materials and utilizes pressure plate 63 which is centrally positioned thereunder as presented in FIG. 8. Strainer insert 64 provides a series of teeth 65 to maintain basket strainer 51 in firm engagement within sink 66 as shown in FIG. 7. Suction cup release lever 67 also is shown in FIG. 7 which is affixed to the side of suction cup 61. Release lever 67 is employed when it is desirable to remove plumbing tool 60 by pressing downwardly therealong whereby lip 68 will be lifted and the suction force dissipated so tool 60 can be easily removed therefrom.
In use, after disposal trap 36 is conventionally placed in sink opening 28 as seen in FIG. 4, tool 30 is pressed downwardly against inner surface 37 of sink 32 with transverse member 33 in its upper most position. Suction cups 31, 31' will firmly grip surface 37. Manual force can then be applied to knob 29 causing pressure member or plate 34 to contact flange 35 of trap 36, and flange 35 is forced against surface 37. Pawl 27 which is spring-loaded engages teeth 26 on transverse member 33 to "lock" member 33 in its downward posture. Once installation of the disposal is completed from beneath sink 32, suction cups 31, 31' are lifted and tool 30 is easily removed.
The embodiment of tool 60 as seen in FIGS. 7 and 8 is likewise easily employed, but tool 60 has only a one step attachment method. Tool 60 is positioned over basket strainer 51 and is pressed downwardly whereby pressure plate 63 urges strainer 51 tightly into sink opening 69 and basket insert teeth 65 prevent strainer 51 from rotating. A suction force is achieved by suction cup 61. To release cup 61, lip 68 is lifted by applying finger pressure to release lever 67 mounted on the side of cup 61. Handle 62 allows for convenience in removing tool 60 from sink 66 which may have small inside dimensions and could not accommodate wider tool 10 as seen in FIG. 1.
The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.
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A plumbing tool having a suction producing effect allows for the convenient installation of plumbing components which are mounted on barriers such as within sinks which cannot be conveniently held in place by a lone individual during installation. The suction device acts as an extra "band" to allow the plumber to install and assemble components on opposite sides of sinks in a quick, safe efficient manner.
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This invention relates to plastic fasteners, and more particularly, to continuously connected plastic fastener stock.
Continuously connected plastic fastener stock, and techniques for securing and dispensing fasteners from such fastener stock, are disclosed in U.S. Pat. No. 4,121,487, issued Oct. 24, 1978; U.S. Pat. No. 4,039,078, issued Aug. 2, 1977 and U.S. Pat. No. 3,948,128 issued Apr. 6, 1976. In these patents fastener attachment stock is formed by continuously connected plastic side members that are intercoupled by a plurality of cross links. The stock may be produced from flexible plastic materials, such as nylon, polyethylene and polypropylene, by molding or stamping.
Such attachment members can be dispensed to couple buttons to fabric, merchandising tags to articles of commerce, and in the general attachment of one item to another, such as the attachment of tubing to a chassis or electrical wiring to a frame.
FIG. 24 shows a prior art embodiment of continuous fastener stock 100 of the same general type as that of the present invention. Elongated, continuous side members 102 and 108 are cross coupled by a plurality of cross-links or filaments 105. Side member 108 comprises a plurality of tab or paddle end members 107 joined together by severable connectors 109. Side members 51 comprise a plurality of end-bars or T-bars 103 optionally joined by severable connectors 104.
As shown in FIG. 25, the filaments 105 of such prior art fastener stock are approximately D-shaped in cross-section with the maximum width at a substantially flat plane at one side thereof. In the assignee's commercial embodiment of such fastener stock shown in FIG. 26 (which is a close up perspective view from above of the connector region 104 of the end-bar 102 of FIG. 24), the severable connectors of end-bar 102 are defined by a castle shaped indentation 112. This design sometimes left a "tail" remnant 117 after severing the T-bar connectors, as shown in FIG. 27. This remnant 117 could cause jamming during ejection of the fastener through the needle bore, as the remnant could wedge between the ejector rod and the needle. Such remnants also led at times to the T-bar pulling out of a garment as the needle was withdrawn after dispensing the fastener ("T-bar pull-out"). Furthermore, the engagement of the end-surface 103s of the severed T-bar by the ejector or plunger was somewhat unreliable due to the angled configuration of surface 103s.
Accordingly, it is a principal object of the invention to provide improved continuously connected fastener stock. Such improvement should result in more reliable dispensing of such stock. It is desirable to reduce the jamming of fastener dispensing apparatus, and "T-bar pull-out".
SUMMARY OF THE INVENTION
The invention provides improved fastener stock of the type having two continuous, elongated plastic side members cross coupled by a plurality of filaments, such stock being proportioned to be fed as a unit to a position where individual fasteners are separated therefrom within a machine. One of the side members is proportioned so that each separated fastener includes an end-bar formed from a portion of said side member and configured for feeding through the bore of a hollow needle having a longitudinal slot for passage of the associated filament. The improvement resides in the configuration of the end-bar with a plurality of severable connectors intermediate respective filaments, such connectors being defined by respective saw-tooth-like indentations in the end-bar to define the connectors. The saw-tooth-like indentations are defined by a steep surface which is either perpendicular to or at a slight diverging angle from a perpendicular to the longitudinal axis of the end-bar, and a more obliquely sloped surface. When the fastener stock is severed at the apex of such indentation or on the side of said apex at the steep surface, a clean, flat end surface of the severed end-bar results, which facilitates the dispensing of the severed fastener.
The steep surface may be at a perpendicular to the longitudinal axis of the end-bar, but it is preferred to form such surface at a slight diverging angle from such perpendicular, illustratively on the order of 5°. The fastener stock may be formed with a trumpeted outer surface adjacent such steep surface, thereby to provide a more suitable configuration of the severed end-bar for engagement by an ejector rod or plunger in dispensing the fastener through the hollow needle.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and additional aspects of the invention are illustrated in the following detailed description of a preferred embodiment of continuously connected fastener stock and of a fastener dispensing gun for use therewith, which should be taken together with the drawings in which:
FIG. 1 is an elevation view of the gun as seen from the left side, with most of the left halves of the handle and trigger removed, showing the trigger in its rest position;
FIG. 2 is an elevation view of the lower part of the gun casing with the left half removed, showing the trigger engaged by the catch lever;
FIG. 3 is an elevation view corresponding to FIG. 2, showing the trigger fully depressed;
FIG. 4 is a partial elevation view of the upper part of the gun as seen from the left side with the left half removed, showing the actuator slide at its forwardmost position;
FIG. 5 is a partial sectional view of the gun from above, showing the cam bar and related mechanisms;
FIG. 6 is a rear sectional view of the upper part of the gun, in a section through the actuator slide;
FIG. 7 is a sectional view from the left side of the shuttle assembly and cam bar, in a section taken in the plane of the needle bore, showing a fastener aligned with the needle;
FIG. 8 is a top view of the gun, with part of the casing removed to display mechanisms at the left half of the gun;
FIG. 9 is a top view of the gun corresponding to FIG. 8, at the level of the fastener feed track;
FIG. 10 is a sectional view of the fastener antiback device of the needle assembly at the Section 10--10 of FIG. 8;
FIG. 11 is a sectional view of the fastener feed track at the section 11--11 of FIG. 8;
FIG. 12 is a top sectional view of the shuttle assembly and adjacent mechanisms including the feed finger advance, showing the fastener stock fed advanced into the shuttle prior to severing of a fastener;
FIG. 13 is a top sectional view of the shuttle assembly and adjacent structures, showing the fastener slide advanced to move a second fastener in-line with the needle bore;
FIG. 14 is a top plan view of the needle assembly;
FIG. 15 shows the needle assembly from the left side;
FIG. 16 is a bottom view of the needle assembly;
FIG. 17 is a sectional view of the needle assembly in the section 17--17 of FIG. 16;
FIG. 18 is a partial sectional view of the needle assembly in the section 18--18 of FIG. 14;
FIG. 19 is a sectional view of the needle in the section 19--19 of FIG. 14;
FIG. 20 is a top view of the metal needle;
FIG. 21 is a side view of the needle;
FIG. 22 is a sectional view of the needle shank in the section 22--22 of FIG. 20; and
FIG. 23 is a rear view of the needle.
FIG. 24 is a plane view of continuously connected fastener stock according to the prior art;
FIG. 25 is a perspective view of a portion of the prior art fastener stock of FIG. 24 illustrating one end-bar and its associated connectors;
FIG. 26 is another perspective view of the end-bar, in a magnified view of the severable connector region of said end-bar;
FIG. 27 shows the end-bar connector region of FIG. 26, after severing;
FIG. 28 is a perspective view of the end-bar configuration according to a preferred embodiment of the invention, in a perspective corresponding to the prior art view of FIG. 26;
FIG. 29 is a sectional view of the connector region taken through the indentation center line of FIG. 28; and
FIG. 30 is a detail view of the apex of the end-bar indentation.
DETAILED DESCRIPTION
With reference to the drawings, an apparatus or gun 10 for dispensing attachment members from improved continuously connected fastener stock in accordance with the invention is shown in FIG. 1.
The fasteners are of the continuously connected type shown in U.S. Pat. No. 4,288,017 which issued Sep. 8, 1981. As shown in FIG. 1 hereof, each individual fastener 101 includes a filament 105 which extends between a head member or paddle 107 and an opposite end member or T-bar 103. The heads and opposite ends of successive fasteners are joined by severable connectors to form continuously connected fastener stock. Thus, as seen in FIGS. 9, 13 which show the fastener stock 100 in section, the T-bars 103 are joined by severable connectors 104. These connectors are severed within the tool 10 using the apparatus of the invention, discussed below. The connections between successive paddles 107 is severed after an individual fastener has been ejected from the tool, as explained below.
Now having reference to the partial perspective view of FIG. 28, applicant has invented an improved fastener stock 100 of the type illustrated in FIG. 24, which facilitates the severing and dispensing of individual fasteners 101 from such stock. FIG. 28 is a perspective view of the connector region of end-bar 102, corresponding to the prior art view of FIG. 26. Applicant has replaced the symmetrical "castle" configuration of FIG. 26 with a substantially saw-tooth-like design--referring to the shape of the metal fixture in the mold which forms this connector. The indentation 113 defining the connector advantageously includes, on one side, a steep surface 114 at a slight angle from the connector center line (i.e. from a perpendicular to the longitudinal axis of the end-bar); illustratively such angle is on the order of 5°. This surface eventually serves as the area of engagement of fastener 101 by the ejector rod 60. After severing, this area 114 becomes a substantially flat face which provides an excellent interface with the ejector rod. On its other side, the indentation 113 is more obliquely angled from the apex 115 of indentation 113, at surface 116, to provide a broader clearance region. The surface 116 on this side may take any form consistent with the need to provide adequate relief of the end bar material. FIG. 29 shows a sectional view of the end-bar connector region in the section taken at 29--29 in FIG. 28. FIG. 30 is a detail view of the apex region 115 (dotted line region in FIG. 28) which shows a radiused configuration providing only a limited surface for severing--thereby avoiding formation of remnants.
As shown at 118 the end-bar 102 advantageously has a trumpeted shape which helps to assure good interface with the ejector rod. This may be defined by a surface 118 which is perpendicular to the steep surface 114. Applicant has observed that the deformation of this region during severing of fastener stock formed of soft plastic materials like polypropylene results in an excellent configuration of the severed T-bar for interface with the plunger.
The fastener stock of the invention is especially adapted for continuous molding and for feeding and dispensing as hereinafter described. Continuous molding of continuously connected fastener stock is illustrated in commonly owned U.S. Pat. No. 4,456,123.
The improved fastener stock of the invention may be used with the assignee's prior art dispensing apparatus of U.S. Pat. No. 4,456,161. In such apparatus, as noted above, separation of T-bars 103 occurs by rotating the leading end-bar about connector 104 into a position of alignment with the needle bore. The exposed end-bar is then driven against a knife surface at the back of the needle to sever the connector 104. Using such severing technique, the improved saw tooth design of the present invention creates a smaller cutting area than the prior art design of FIG. 26; avoids formation of a remnant "tail" as shown in FIG. 27; and presents an excellent interface with the ejector rod. Alternatively, the improved fastener stock 100 may be employed with the fastener dispensing apparatus discussed below.
Referring again to FIG. 1, the gun is formed by a hollow casing or handle assembly 12, and is hand actuated by a trigger 16. The casing is preferably in two halves, a left handle 14 and right handle 15, which may be joined together in conventional fashion using, for example, screw fasteners, and fabricated from any convenient material, such as molded plastic. Similarly, the trigger 16 may consist of left half 17 and right half 19. Various features within the handle 12 and trigger 16 may consist of dual structures within the respective body halves, but the following discussion refers only to single structures for the sake of simplicity. In FIG. 1, the left handle 14 is removed for clarity. Trigger assembly 16 is held biased against the handle assembly 12 by a compression spring 23 which reacts against spring post 28. The trigger rotates about pivots 26 in the handle assembly. Motion is restricted in the open position (as shown in FIG. 1) by the engagement between a stop tab 25 located on the trigger and a bumper 27 housed in the handle. The spring post 28 reacts against and rotates in a pivot 29 in the handle assembly. The trigger assembly houses a spring retainer 21 pivottably mounted between the trigger halves.
A drive link assembly 30 connects the trigger 16 to an actuator slide 35, which in turn drives various major functional assemblies of gun 10 as explained below. The drive link assembly 30 is comprised of drive link 31, idler link 33, the actuator slide 35 and two pivot pins 34 and 42. A boss 32 travels in a slot 37 in the trigger and transmits trigger motion to the drive link assembly 30 as the trigger 16 is rotated about pivot 26. The drive link 31 is attached to actuator slide 35 by the pivot pin 34. The idler link 33 rotates between drive link 31 (to which it is pivotally connected by pin 42) and a pivot 41 in the handle assembly. This produces lost motion of the upper end of drive link 31, during linear motion of the actuator slide 35. The rearward motion of trigger 16 is limited by bumper 43. This drive link arrangement maintains mechanical advantage and provides a linear force profile, as the trigger 16 is depressed.
Trigger antiback assembly 40 controls the motion of trigger 16, with operational advantages explained below. Trigger antiback assembly 40 includes a catch lever 45 pivotally mounted within the handle at pin 51. Lever 45 is biased toward its position shown in FIG. 1 by virtue of the over-center mounting of a compression spring 46 between a spring retainer 48 and spring pivot 49. When the trigger 16 is depressed, the catch lever 45 is cammed over-center by the action of stop tab 25 against cam surface 52. If the trigger is not fully depressed, but has rotated beyond the position at which stop tab 25 rides over locking tab 55, stop tab 25 will be engaged in the cavity 54 preventing return rotation of the trigger 16. (See FIG. 2). As will become more evident in the further explanation of the fastener feed mechanisms, this locking or antiback action occurs at the point at which the feed of the fastener stock 100 has begun. Trigger 16 must then be completely rotated to its rearward position to cam the catch lever 45 into the position shown in FIG. 3 and thereby clear the lever 45 out of the way to permit return rotation of the trigger 16.
As seen in FIGS. 4-6, the actuator slide 35 moves along a linear path, sliding between tracks 58 and 59 in the handle halves 14 and 15.
Actuator slide 35 serves three functions in gun 10:
(1) To eject a fastener through needle 140 by advancing an ejector rod 60;
(2) To actuate the feed finger advance 68 which feeds the fastener stock 100 to a shuttle assembly 80; and
(3) To provide motion to the cam bar 65 which in turn reciprocates shuttle assembly 80. This linear shuttle motion comprises distinct motions of a knife slide 81, knife 83, and fastener slide 85, as explained below.
Having reference to FIGS. 4, 6, the actuator slide 35 includes an upright support 38 to which the ejection rod 60 is secured at its upper end. Thus, the forward stroke of the actuator slide 35 causes the forward motion of the ejector rod 60 through needle 140.
As seen from above (FIGS. 9, 13), the feed finger advance 68 includes a series of saw teeth 69 which urge the fastener stock 100 forward during the forward motion of feed finger advance 68, but permit the feed finger 68 to slide over the fastener filaments 105 during the rearward motion of this structure thereby to engage a successive fastener. Feed finger advance 68 is biased toward the fastener stock 100 by leaf spring 73. As seen in FIG. 4 the feed finger advance 68 has a pair of depending legs 71, 72; note also the rear sectional view of this structure in FIG. 6. The actuator slide 35 has a protuberance 47 (FIGS. 4, 5) which abuts against the legs 71, 72 as the actuator slide 35 approaches its forward and rearward extremes of travel, respectively. By this means, the feed finger advance 68 advances the fastener chain 100 over the pitch of one fastener during each actuation of the trigger 16, in particular as the trigger reaches and moves past the position shown in FIG. 2. By the same means, the feed finger advance 68 is retracted on the rearward stroke of the actuator slide 35 (return rotation of trigger 16) to engage the next fastener in chain 100.
As best seen in FIG. 6, actuator slide 35 slides within two tracks 58, 59 in handle halves 14, 15. Tracks 58, 59 define a linear path. As seen in FIG. 5, a cam bar 65 is pivotally mounted at the rear of tool 10, at 66, and fits within a tapered cavity 36 in actuator slide 35. The forward or rearward motion of actuator slide 35 results in lateral motion of the front of cam bar 65 when the actuator slide engages the inclined cam region 67 causing a slight swinging of the cam. This in turn causes lateral motion of the mechanisms of shuttle assembly 80 as discussed below. This arrangement positively drives the shuttle motion in both directions.
Continuously connected fastener stock 100 is fed from a suitable supply, such as the supply spool 75 shown in FIG. 1. Referring to the top views of FIGS. 8, 9, the fastener stock 100 passes from the supply assembly 75 into feed track 120 at the top of the tool, so that the interconnected T-bars 103 of the fasteners are firmly engaged within the track (FIG. 9) while the filaments 105 and paddles 107 project from the top of the tool. One of the particularly novel aspects of this tool design is the incorporation of a needle assembly 130 which cooperates with a mating portion of the tool body to define the fastener track. As shown in FIG. 11, which is a section taken at 11--11 in FIG. 8 at the entry region of the feed track 120, needle assembly 130 mates with right handle 15 to define the feed track 120.
The needle assembly 130 incorporates an antiback mechanism 135 which prevents the fastener stock 100 from backing out of the feed track 120 during operation. As shown in FIG. 8 and the isolated views of the needle assembly in FIGS. 14, 16, the antiback mechanism 135 comprises a living hinge, i.e. a flexible finger integral with the needle assembly 130 and having a saw tooth 136 which engages the fastener filaments 105. Because of the mild slope of its leading edge the antiback tooth 136 permits the fastener to advance while the antiback 135 deflects out of the fastener path; the tooth 136 has an abrupt rear surface to prevent the retrograde motion of a fastener which has moved past it. As seen in FIG. 10 which is a section taken at 10--10 in FIG. 8, antiback 135 includes a pin 137 which permits the operator to deflect the antiback 135 in the direction indicated by arrow A, and a second pin 138 which forces the feed finger advance 68 out of the fastener track; the operator may then unload the chain of fasteners from the track 120. The lower pin 138 fits within a slot 68a in the feed finger advance (FIGS. 9, 12).
Thus, the needle assembly 130 contains not only the needle--the means by which a fastener is inserted into an article to be marked--but also defines the fastener feed track, contains the fastener antiback mechanism, and provides the release mechanism which permits unloading the fastener stock from the tool. Other features of the needle assembly, and its manufacture, are discussed below.
A portion 123 of the fastener track 120 on either side of the antiback 135 is essentially straight and parallel to the ejection axis, that of the needle 140 and ejector rod 60. This feed track segment 123 leads up to the transfer section 125 of the feed track at which shuttle assembly 80 severs an individual fastener from fastener stock 100, and move the fastener laterally to the ejection axis.
Referring to FIG. 7, the knife slide 81 acts as the main shuttle mechanism which carries the knife 83 and fastener slide 85 during the operation of the tool. As seen in FIGS. 5, 13, a compression spring 86 biases the knife slide 81 toward the left handle. Knife slide 81 includes a boss or cam yoke 87 which connects it to cam bar 65 and transmits the lateral motion of the cam to the knife slide. As seen in FIGS. 7, 13 the knife 83 is fixed to knife slide 81 to move therewith. The fastener slide 85 is retained by knife slide 81 by means of a tongue and groove mechanism 89. It is free to slide in parallel with the knife slide between upstanding walls 81w of the knife slide. Fastener slide 85 is held biased toward the left side of the knife slide by compression spring 88. Thus, the main compression spring 86 biases the entire shuttle assembly to the left side, while the secondary spring 88, which has a lower spring constant than spring 86, only biases the fastener slide 85. By this arrangement, the fastener slide serves as a secondary shuttle which yields when it meets interference with a fastener to compress the spring 88 (FIG. 12). This motion of the fastener shuttle exposes the cutting surface of knife 83 to the fastener stock, and the fastener slide 85 allows the knife slide 81 further motion to the right until the knife cuts the fastener at the thin connector 104. Thereupon, spring 88 returns the fastener slide 85 to its home position and forces the severed fastener against the exit slot of needle 140 (FIG. 13), after the plunger 60 withdraws to the rear. An elevated portion at the right side of fastener slide 85 defines a wall surface 85s for engaging T-bar, while a further elevated finger 85f engages the filament 105 (FIG. 13). The system is calibrated to continue to maintain pressure on the fastener against the wall of the needle entry.
Applicants have observed that a straight shearing of the T-bar section of continuously connected fastener stock requires an unduly high force. They have discovered that by putting a thin, sharp knife alongside a yieldable transfer mechanism, and cutting the fastener stock just as the transfer action commences, the cutting force required is markedly reduced. In the shuttle assembly 80, the transfer mechanism is a reciprocating slide, but alternatively the transfer device could be an oscillating rotor which is biased clockwise or counter clockwise. The transfer slide or rotor, or at least a portion thereof which is adjacent the knife, is yieldable so that the T-bar section can deflect as the knife is cutting. By allowing this deflection, the knife can make a clean square cut with a relatively small force, and the T-bar section will be returned to its original straight configuration once the cut is completed. The feed track and ejection track preferably should be parallel to each other and in close proximity (illustratively, on the order of 3 millimeters). A transfer device designed as described above can simultaneously cut an individual "T" bar and transfer it in line with the ejection track.
The transfer mechanism described above requires a straight line motion for severing and transferring an individual fastener. In the manual tool of the preferred embodiment, the shuttle is spring biased toward the left side, to provide the force for cutting the fastener. This biasing also allows the shuttle assembly 80 to properly interface with the cam bar 65. Although the illustrated tool depends on a spring force to urge the knife slide 81 toward the ejection axis, it is also feasible to rely on an electrically or fluidically powered mechanism to positively drive the knife slide.
Reference should now be had to FIGS. 14-23 which illustrate the preferred construction of a needle assembly 130 for use with the tool 10. As seen in the side view of FIG. 15 and bottom view of FIG. 16, needle assembly 140 includes three downwardly protruding posts 147 and a rib 144 at the front of the assembly, and a locking tab 149 toward the rear of the assembly. (See also FIG. 18 which shows a sectional view of the locking tab 149). Referring to FIG. 1 as well as FIGS. 14 and 16, the needle assembly 140 also includes a downward keyhole-shaped projection 146 which may be rotated by the operator by means of a needle lock knob 145. Locking tab 149 and projection 146 are designed to fit into apertures 151 (FIG. 12), 152 (FIG. 9), in the right half of the tool body, while posts 147 and rib 144 support the needle assembly against walls of the tool body. To insert a replacement needle assembly into the tool, the operator inserts locking tab 149 into a slot opening in the handle half 15, and exerts slight backward pressure while seating the front part of the needle assembly in place. The user then rotates needle lock knob 145 a half turn to lock the needle assembly in place due to the mating of the cam surface 146c of projection 146 with an aperture within the tool body.
As explained above, needle assembly 130 is configured to define the fastener feed track 120 in conjunction with the tool body (FIG. 11). The needle assembly 140 is shaped to provide an arcuate entry feed path 122 (FIG. 8) followed by a straight path 123 parallel to the ejection axis, and a short, transversely oriented transfer path 125 (FIG. 8) leading up to the entry region of the needle. FIG. 17 shows the entry region of the needle assembly 140 as seen from the rear.
FIGS. 20-23 provide various views of the hollow, slotted metal needle 140 from the needle assembly 130. Advantageously, the needle 140 is stamped and rolled into the configuration shown, as known in the prior art. The remainder of the needle assembly is then formed of a thermoplastic material such as nylon, which is injection molded around the metal needle 140. FIG. 19 shows a sectional view of the needle assembly taken at section 19--19 in FIG. 16, in a transverse section through the needle lock.
The sequence of operation of tool 10 is as follows. When the tool is in its relaxed configuration (FIG. 1), a completely severed fastener 101 is loaded into the needle 140 for ejection. A tag is placed over the needle 140 and the needle inserted through the article to be marked. Trigger 16 is then squeezed and the drive linkage is actuated as explained above. Actuator slide 35 begins to advance and carries ejector rod 60 into the back end of the T-bar 103 of fastener 101 (FIG. 13). Continued motion of the mechanism causes the fastener T-bar to be loaded into the bore of hollow needle 140. Further motion causes T-bar 105 to continue to travel down the bore of hollow 140, and begins the motion of knife slide 81. The actuator slide 35 interacts with the cam bar 65 as explained above to impart a slight rotational motion to the cam. This causes the front end of the cam to move to the right, carrying with it the knife slide 81 by means of the boss 87. Thus, the fastener slide 85 and knife 83 are also displaced to a point at which the shuttle is aligned with the feed track 120 (FIG. 12).
Continued motion of the actuator slide begins actuation of the feed finger advance 68. At this point in the cycle, the trigger antiback 45 is actuated and the trigger assembly cannot be released until the tool has completed its cycle. Feed finger advance 68 begins pushing on filament 105 of the fastener until it is indexed one complete pitch of the fastener chain, loading the connected chain into the shuttle mechanism, and indexing the next fastener in line beyond the antiback portion 135 of needle assembly 130. During this time, ejector rod 60 completes ejection of the fastener 101 through hollow needle 140, the tags, and the article to be marked, completing the forward cycling of the tool, and clearing the trigger antiback 45.
The tool may be removed from the goods now marked with the trigger still completely squeezed; by releasing the trigger prior to withdrawal of the tool from the goods; or while releasing the trigger simultaneously with withdrawing the needle from the goods. As the needle is withdrawn from the article to be marked, the T-bar 103 will resiliently resume its transverse orientation with respect to filament 105. This will prevent withdrawal of the filament from the material. Motion of tool 10 as it is removed from the article will break the connection between the paddle 107 of the ejected fastener and the paddle of the next fastener, in the manner illustrated in U.S. Pat. No. 3,733,657.
Releasing of trigger assembly 16 causes the following events to occur:
The ejector rod 60 begins to withdraw from needle 140 as actuator slide 35 moves back within the tool. Continued rearward motion of actuator slide 35 commences the movement of shuttle assembly 80 by rotating the cam bar 65 which urges the boss 87 of knife slide 81 to the left. As the knife slide 81 moves to the left, the fastener stock 100 arrests the motion of the fastener slide 85 by compression spring 88 and begins to expose the knife 83. Full exposure of knife 83 to the fastener stock severs the end most fastener 101 from the remainder of the fastener stock 100. The cut fastener is then pushed to the left side of the tool by the compression spring 88 into contact with the ejector rod 60 which is continuing to withdraw from the needle assembly 130. Continued return motion of trigger 16 withdraws ejector rod 60 from the shuttle section of tool 10 and begins to withdraw the feed finger advance 68 to a point beyond fastener antiback 135. Completion of the rearward stroke of actuator slide 35 results in the complete withdrawal of the ejector rod from the shuttle section allowing the severed fastener 101 to be completely loaded into its ejection position in preparation for a subsequent actuation of the tool.
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Improved continuously connected plastic fastener stock for attaching price tags to garments and other joining applications. The fastener stock includes two side members connected by a series of filaments, one of the side members comprising a series of severally connected T-bars. The T-bar connectors are defined by saw-tooth-like indentations in that end bar, having a perpendicular or slightly angled surface which is eventually engaged by the plunger when ejecting the severed T-bar.
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BACKGROUND OF THE INVENTION
This invention relates to improved methods for manufacturing extremely thin, very delicate metallic structures possessing grid-like patterns of minute, closely spaced, precisely dimensioned apertures. Such apertured metal structures, hereinafter referred to as "microsieves", are especially useful in sorting and sieving objects of only a few microns in size. One such microsieve, designated a "cell carrier", is described in Spanish patent No. 522,207, granted June 1, 1984, and in commonly assigned, copending U.S. patent application Ser. No. 550,233, filed Nov. 8, 1983, the disclosure of which is incorporated by reference herein, for classifying biological cells by size. The cell carrier is prepared employing a modified photo-fabrication technique of the type used in the manufacture of transmission electron microscope grids. The cell carrier is on the order of only a few microns in thickness and possesses a numerically dense pattern of minute apertures. Even with the exercise of great care, the very delicate nature of the cell carrier makes it difficult to manipulate, for example, to insert it in a holder of the type shown in aforesaid U.S. patent application Ser. No. 550,233, without causing it appreciable damage, frequently in the form of a structural deflection or deformation which renders it useless for its intended use.
In order to better understand and appreciate the improvements and advantages made possible by the present invention, the foregoing known type of microsieve, or cell carrier as it is called, and a method for its manufacture will be described in connection with the accompanying figures of drawing, all of which are greatly enlarged in size and with certain features exaggerated for the sake of clarity, in which FIG. 1(a) is a plan view of the cell carrier, FIGS. 1(b) and 1(c) are perspective and side elevational views, respectively, of a typical secticn of the cell carrier and FIGS. 2(a) through 2(e) are side elevational views of successive steps in the manufacture of a section of the cell carrier.
The cell carrier 10 shown in FIG. 1(a) is a very thin metallic disk, for example, about 8 to 10 microns in thickness, with a square-shaped, grid-like pattern of apertures 11 with centers about 15 microns apart defined within its geometric center. The cell carrier can be fabricated from a variety of metals including copper, nickel, silver, gold, etc., or a metal alloy. The apertures actually number 100 on a side for a total of 10,000 apertures and are thus able to receive, and retain, up to 10,000 cells of the desired size with each cell occupying a single aperture. Keyway 12 is provided to approximately orient the cell carrier within its holder.
As shown in FIGS. 1(b) and 1(c), a representative section of grid 11 of cell carrier 10 possesses numerous apertures or holes 20 arranged in a matrix-like pattern of rows and columns along axes X and Y respectively. This arrangement makes it possible to label and locate any one aperture in terms of its position along coordinates X and Y. The shape of apertures 20 enables biological cells 21 of preslected dimensions to be effectively held to the carrier by applying means, such as a pressure differential between the upper and the bottom side of the carrier, or electromagnetic forces. To first separate a particular group of cells from cells of other groups, carrier 10 is chosen to have apertures of sizes so that when the matter, for example, blood, containing the various cell groups is placed on carrier 10, most, if not all, of the apertures become occupied by cells of the group of interest with each aperture containing one such cell. Thus, the apertures can be sized to receive, say, lymphocytes of which there are two principal sizes, namely, those of 7 microns and those of 10-15 microns, with the former being the cells of most interest and the latter being washed away from the upper surface 10t of the grid under a continuous flow of fluid. To capture and retain the smalle size lymphocytes, apertures 20 will have an upper cross-sectional diameter of about 6 microns and a lower cross-sectional diameter of about 2 microns or so. In this way, a lymphocyte from the desired population of cells can easily enter an aperture but once it has occupied the aperture, it cannot pass out through the bottom side 10b of the carrier. The cut-out areas 30(d) about the bottom of each aperture have no functional significance and result from the procedures whereby the cell carrier is manufactured as discussed below in connection with FIGS. 2(a) through 2(e).
In the initial steps of the known method of manufacturing cell carrier 10 which are illustrated in FIGS. 2(a) through 2(e), a layer of photoresist 30, e.g., a photoemulsion, having a thickness, or height, generally on the order of about 1 micron or so, is applied to a metallic base plate, or mandrel, 31, e.g., of copper, upon which the carrier is to be formed. In FIG. 2(b), photoemulsion layer 30 has been selectively exposed to a source of actinic radiation employing a conventional mask procedure to produce a patterned surface of discrete areas of unexposed photoemulsion 30(a) surrounded by a continuous area 30(b) of exposed photoemulsion. Following conventional treatment of photoemulsion layer 30 with developer, fixer and finally, with clearing agent to wash away exposed area 30(b), there remains discrete areas of fixed photoemulsion 30(a) supported upon mandrel 31 as shown in FIG. 2(c). These fixed areas of photoemulsion correspond to the sites later defining the bottoms of apertures 20 in the finished carrier 10 and most frequently will be circular in cross-section. As shown in FIG. 2(d), a continuous layer of metal 30(c), e.g., copper, gold, nickel, silver, etc., or metal alloy, which is to provide the body of cell carrier 10, is electrodeposited upon mandrel 31. Since fixed areas 30(a) of the photoemulsion 10 are very thin, in order to build up the thickness of the carrier, or aperture height, some of metal 30(c) will inevitably overflow onto the peripheral edges of fixed areas 30(a) to form an aperture having a cone-shaped bore. Clearly, as one increases the thickness of the electrodeposited metal, the steeper will be the slope of the ultimate aperture bore. To prevent the aperture from becoming occluded by the overflow of electrodeposited metal, it is necessary to place the areas of fixed photoemulsion further apart as the thickness (i.e., the height) of electrodeposited metal layer 30(c) is increased. This has the necessary consequence of reducing the number of apertures which can be formed in the metal structure as its thickness is increased. In the final manufacturing steps shown in FIG. 2(e), mandrel 31 is removed and the fixed areas 30(a) of the photoemulsion are dissolved, or etched, away to provide carrier 10 containing the desired pattern, or grid, of apertures 20. A circumferential cut-away area 30(d) which possesses no role in the operation of the cell carrier is defined in the bottom of each aperture once fixed photoemulsion areas 30(a) are removed.
The aforedescribed method for making a microsieve is subject to a number of disadvantages, foremost among them being the practical difficulty of providing a sufficient thickness, or aperture height, without simultaneously unduly reducing the numerical density of the apertures. In addition, because of the thinness of the microsieve (typically weighing about 400 micrograms or so) which is obtainable by this manufacturing method, the structure is mechanically very fragile and as a result, is difficult to manipulate without causing it to be distorted or damaged. Still another disadvantage lies in the fact that the sloping sides of apertures 20 make it easy for them to be occupied by more than one cell. Ideally, an essentially vertical slope is desired to prevent or minimize this possibility; however, such a slope cannot be obtained with the foregoing method.
Other prior art which may relate to one or more features of the present invention can be found in U.S. Pat. Nos. 2,968,555; 3,139,392; 3,190,778; 3,329,541; 3,403,024; 4,058,432; 4,388,351; and 4,415,405.
SUMMARY OF THE INVENTION
By way of overcoming the foregoing drawbacks and deficiencies associated with the prior art method of manufacturing a microsieve, and the limitations inherent in the microsieve so manufactured, it is a principal object of the invention to provide a microsieve having a greater rigidity than heretofore practical or obtainable, and consequently, having a much greater resistance to mechanical distortion and other damage when manipulated as compared with the afore-described known type of microsieve.
It is another object of the invention to provide a microsieve in which the required rigidity is imparted thereto by the fact that it is integral with a rigid, self-supporting frame.
It is another object of the invention to provide a microsieve in which the required rigidity is imparted thereto by the fact that it has a greater thickness than has been dislosed in the prior art.
It is another object of the invention to provide a microsieve in which the required rigidity is imparted thereto by the fact that it is built up from successively laminated microlayers.
Yet a further object of the invention is to provide a microsieve in which a substantial proportion of the walls of the individual apertures are essentially perpendicular to the microsieve surface.
In keeping with the foregoing objects, an ordinarily delicate microsieve is provided with greater resistance to mechanical distortion by being integrally formed with a rigid frame or by having its thickness built up to an extent where it is significantly more capable of with-standing flex.
Since the microsieve is formed as an integral part of a larger, frame member, it can be readily handled without significant risk of damage.
The term "microsieve" as used herein shall be understood to include not only cell carriers and similar devices but other kinds of precision sieves, screens, grids, scales, reticules, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) through 1(c) and 2(a) through 2(e) are illustrative of a known type of microsieve and its method of manufacture and are fully described above.
FIG. 3 is a side elevational, greatly enlarged view of a portion of one embodiment of microsieve in accordance with this invention.
FIGS. 5(a) through 5(f) are side elevational views of successive steps in the manufacture of a frame-supported microsieve in accordance with the present invention.
FIGS. 6, 7, 8(a) and 8(b) are side elevational views illustrative of still other embodiments of microsieves in accordance with this invention and the methods used in their manufacture.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is illustrative of a preferred microsieve in accordance with this invention shown generally at 10. As shown, the sides of apertures 20 are essentially vertical in contrast to the sloping sides of the apertures in the prior art microsieve of FIGS. 1(a)-(c). This arrangement helps to lessen the opportunity for more than one cell to occupy more than one aperture and also minimizes distortion of the light path which can result from apertures with comparatively gentle sloping walls.
Microsieve 10 of FIG. 3 is made by a modification of the known method illustrated in FIGS. 2(a)-(e). Specifically, instead of laying down a thickness of photoresist 30 of only about 1 micron as in FIG. 2(a), the thickness of the photoresist layer is made to be about 7 microns or so. Thus, when the fixed areas of photoresist are eventually removed to provide the sieve, undercut areas 30(d) will actually have the straight-bore configuration shown in FIG. 3. In use, the undercut areas 30(d) of microsieve 10 face upwardly, i.e., toward upper face 40. At upper face 40, the diameter of apertures 20 is about 6 microns and in the constricted area 60, the diameter is about 2 microns; the diameter of the opening at under surface 50 of microsieve 10 is of no significance to the functioning of the device.
Microsieve 10 of FIGS. 5(a)-(f) illustrates still another embodiment of the present invention. As shown in FIG. 5(a), surface 13a of rigid frame member 13 which is fabricated from an electrically conductive material such as copper, nickel, gold, silver, etc., is placed against a suitable nonadherent surface 11, e.g., one which is substantially optically flat, either directly thereon or indirectly upon a thin foil 12 which serves as a shim to separate surface 13a a short distance, e.g., 5 to 20 microns or so, from surface 11. Frame member 13 possesses a relatively large aperture 14, preferably circular in configuration and defined within the geometric center of surface 13a of the frame, filled with a hardenable electrically conductive material 15, e.g., Wood's alloy which solidifies below its melting point of about 65° C., to form a smooth surface 17. Electrical contact 16 is inserted before, during or after hardening of electrically conductive material 15. Once electrically conductive material 15 has become hardened, i.e., by being cooled to below its solidification point, it will possess a smooth surface 17 of electrically conductive material corresponding to the configuration of the large aperture 14 and surrounded by surface 13a of frame member 13. The sole function of surface 11 is to provide corresponding surface 17 of the electrically conductive material, when hardened, with a smooth, striation-free surface and that of optional foil 12 to extend surface 17 some short distance beyond surface 13a of frame 13. After electrically conductive material 15 has hardened, surface 13a of frame 13 is removed from contact with surface 11 and inverted to the face-up position as shown in FIG. 5(b). In the latter figure, a layer of photoresist 18, e.g., of a photoemulsion or photopolymerizable composition, is applied to surface 17 of electrically conductive material 15 and, for good measure, to at least a part of surface 13a of frame 13 to insure adequate and uniform coverage of the area which will eventually be occupied by the array of apertures constituting the microsieve. Typically, the height (or thickness) of photoresist 18 will be on the order of about 1 or 2 microns, the precise thickness being dependent in large measure upon the rheological properties of the particular photoresist selected.
In FIG. 5(c), conventional masking/exposure techniques (as described above in connection with FIGS. 2(a)-(e) which are illustrative of the prior art) provide a grid-like pattern of unexposed areas of photoresist 18(a) surrounded by a continuous area of exposed photoresist 18(b). Following conventional developing, fixing and clearing operations, there is provided the fixed areas of photoresist 18(a) supported on Wood's metal 15 as shown in FIG. 5d.
It will be understood that either positive or negative photoresists can be used in the practice of the invention in accordance with procedures which are well known to those skilled in the art.
In the following step shown in FIG. 5(e), a metal 19, e.g., copper, gold, silver, etc., is electrodeposited upon the exposed surfaces of frame member 13 as in the known method of manufacturing a microsieve described above. This electrodeposited metal 19 completely surrounds areas of fixed photoresist. As shown in FIG. 5(f), electrically conductive material 15 is removed from frame member 13, usually with only a simple breaking-away action, and the fixed areas of photoresist are removed by dissolution or etching with an appropriate solvent to provide the finished, completely self-supporting microsieve spanning what had originally been large aperture 14 of frame member 13.
In the variation of the foregoing method illustrated in FIG. 6, copper frame member 13' of microsieve 10' initially does not possess an aperture. However, an etchant resistant, electrically non-conductive coating 20 is applied to the underside of frame member 13' except for an exposed, bare copper metal area 21 directly beneath the microsieve portion to be formed from electroplated nickel 19' layer. An etchant which selectively removes copper metal but which does not affect nickel is then used to remove central copper core 22 and fixed areas 18'b of photoresist are removed to provide a finished microsieve 10' similar to that shown in FIG. 5(f).
In yet another variation of the method described in FIGS. 5(a) through 5(f) which is shown in FIG. 7, central aperture 14 of frame member 13' is filled with a readily meltable or solvent-soluble electrically non-conductive material 30, e.g., a paraffin wax, in place of electrically conductive material 15 of FIG. 5(a). However, prior to applying photoresist as shown in FIG. 5(b), an electrically conductive metal 31, e.g., gold, silver, etc., is vapor deposited upon the complete upper face of frame member 10 to provide electroconductivity even in the area of the aperture occluded by material 30. Thereafter, the steps of applying photoresist, exposing, developing and fixing the photoresist, washing exposed photoresist away and electroplating metal are carried out as before. Finally, material 30 is removed, the exposed thin layer of vapor deposited metal 31 is selectively etched or otherwise removed and the fixed areas of photoresist are removed to provide the finished microsieve.
Another approach to imparting increased rigidity to a microsieve is illustrated in FIGS. 8(a) and (b). Here, the object is to build up the thickness of the microsieve body to the point where it becomes appreciably more resistant to flex, yet without sacrificing the numerical density of apertures.
As shown in FIG. 8(a), copper (or other electrically conductive metal) mandrel 40 possesses successive layers 41 to 53 of electroplated metal, e.g., nickel, surrounding fixed photoresist areas 53b which are in concentric alignment with the previously deposited areas of photoresist therebeneath. This method of manufacturing a microsieve requires that each layer of electroplated metal be no higher, or thicker, than the adjacent areas of fixed photoresist. Optionally, each of layers 41 to 53 can be separated by a layer 54 of vapor deposited metal of only a few angstroms thickness. With the removal of mandrel 40 and the fixed areas of photoresist 53b, there is obtained the finished microsieve 60 shown in FIG. 8(b).
The foregoing method makes it possible to vary the cross-sectional geometry of the aperture from one layer to the next and/or to stagger successive layers to obtain an aperture with a non-vertical bore.
While various aspects of the invention have been set forth by the drawings and the specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described, may be made without departing from the spirit and scope of the invention as set forth in appended claims.
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An ordinarily delicate microsieve is provided with greater resistance to mechanical distortion by being formed integrally with a rigid frame or by having its thickness built up to an extent where it is significantly more capable of withstanding flex.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority under 35 U.S.C. §119 to Korean patent Application No. 10-2013-0138985, filed on Nov. 15, 2013, the disclosure of which is hereby incorporated by reference herein in its entirety.
BACKGROUND
Technical Field
Example embodiments of the invention relate to methods of forming oxide semiconductor devices and methods of manufacturing display devices having oxide semiconductor devices. More particularly, example embodiments of the invention relate to methods of forming oxide semiconductor devices having enhanced electrical characteristics by simultaneously performing an ultraviolet ray irradiation process and a thermal treatment process, and methods of manufacturing display devices including the oxide semiconductor devices.
Description of the Related Art
An oxide semiconductor device including an active pattern containing an oxide semiconductor device may be employed in various display devices such as an active matrix liquid crystal display, an active matrix organic light emitting device, etc.
In conventional methods of forming the oxide semiconductor device, damage to an active pattern may be caused during a process in which a metal thin film for forming a source electrode and a drain electrode is deposited on the active pattern and/or a process in which the metal thin film for forming the source electrode and the drain electrode is patterned. As a result, electrical characteristics of the oxide semiconductor device such as operating current, threshold voltage distribution, mobility, etc. may be degraded because of the damage to the active pattern.
SUMMARY
Example embodiments provide methods of forming oxide semiconductor devices having enhanced electrical characteristics by simultaneously performing an ultraviolet ray irradiation process and a thermal treatment process after forming a source electrode and a drain electrode.
Example embodiments provide methods of manufacturing display devices including the oxide semiconductor devices with enhanced electrical characteristics.
According to one aspect of the invention, there is provided a method of making an oxide semiconductor device. In the method, a substrate comprising a first major surface and a second major surface that faces away from the first major surface may be provided. An oxide semiconductor device may be formed over the first major surface to provide an intermediate device, and the semiconductor device may comprise an oxide active layer. The intermediate device may be subjected to ultraviolet (UV) light (e.g., ultraviolet ray irradiation process) for a first period, and subjected to heat (e.g., thermal treatment process) for a second period. The first and second periods may at least partly overlap.
In example embodiments, the ultraviolet ray irradiation process may be carried out for about 10 second to about 1 hour.
In example embodiments, the ultraviolet ray irradiation process may be executed using an ultraviolet ray having a wavelength between about 185 nm and about 370 nm.
In example embodiments, the ultraviolet ray irradiation process may be performed using the ultraviolet ray generated from an ultraviolet ray lamp or a short wavelength light emitting diode (LED). For example, the ultraviolet ray may have an energy density less than about 254 mW/cm 2 .
In example embodiments, the thermal treatment process may be carried out under an atmosphere including air, oxygen, ozone, nitrogen, or argon.
In example embodiments, the thermal treatment process may be performed for about 10 second to about 1 hour.
In example embodiments, the thermal treatment process may be executed at a temperature less than about 400° C.
In example embodiments, the thermal treatment process may be performed using a hot plate or a furnace.
In example embodiments, the ultraviolet ray irradiation process may comprise applying the UV light from a side of the first major surface of the substrate or from a side of the second major surface of the substrate. Additionally, the thermal treatment process may comprise applying the heat from the side of the first major surface or the second major surface.
In some example embodiments, the ultraviolet ray irradiation process may comprise applying the UV light from both the side of the first major surface and the side of the second major surface. Further, the thermal treatment process may comprise applying the heat from both the side of the first major surface and the side of the second major surface.
In example embodiments, the oxide active layer may include a semiconductor oxide containing a binary compound (ABx), a ternary compound (ABxCy) and/or a quaternary compound (ABxCyDz).
In example embodiments, the oxide active layer may include the semiconductor oxide containing indium (In), zinc (Zn), gallium (Ga), stannum (Sn), titanium (Ti), aluminum (Al), hafnium (Hf), zirconium (Zr) and/or magnesium (Mg).
In some example embodiments, the oxide active layer pattern may have a composition in which lithium (Li), natrium (Na), manganese (Mn), nickel (Ni), palladium (Pd), copper (Cu), carbon (C), nitrogen (N), phosphorus (P), titanium (Ti), zirconium (Zr), vanadium (V), rubidium (Ru), germanium (Ge), stannum (Sn) and/or fluorine (F) is or are added to the semiconductor oxide.
In example embodiments, an etching stop layer may be additionally formed on the oxide active layer. A protection layer may be formed to cover the etching stop layer, a source electrode and a drain electrode.
In example embodiments, the etching stop layer and the protection layer may be formed after the ultraviolet ray irradiation process and the thermal treatment process.
According to another aspect of the invention, there is provided a method of manufacturing a display device. In the method, a substrate comprising a first major surface and a second major surface that faces away from the first major surface may be provided. An oxide semiconductor device may be formed over the first major surface to provide an intermediate device, and the semiconductor device may comprise an oxide active layer. The intermediate device may include a gate electrode formed on the first major surface and a gate insulation layer formed on the first major surface over the gate electrode. The intermediate device may be subjected to ultraviolet (UV) light (e.g., ultraviolet ray irradiation process) for a first period, and subjected to heat (e.g., thermal treatment process) for a second period. The first and second periods may at least partly overlap. Subsequent to subjecting the UV light and the heat, a light emitting diode may be formed over the intermediate device. The light emitting diode may be connected to the oxide semiconductor device and comprise an organic light emitting layer.
In example embodiments, the ultraviolet ray irradiation process may comprise applying the UV light from a side of the first major surface of the substrate or from a side of the second major surface of the substrate. Alternatively, the ultraviolet ray irradiation process may comprise applying the UV light from both the side of the first major surface and the side of the second major surface. The thermal treatment process may comprise applying the heat from the side of the first major surface or the second major surface. Alternatively, the thermal treatment process may comprise applying the heat from both the side of the first major surface and the side of the second major surface.
In example embodiments, an etching stop layer may be additionally formed on the oxide active layer, and a protection layer may be formed to cover the etching stop layer, a source electrode, and a drain electrode.
In example embodiments, the etching stop layer and the protection layer may be formed after the ultraviolet ray irradiation process and the thermal treatment process.
According to example embodiments, the ultraviolet ray irradiation process and the thermal treatment process may be simultaneously carried out after forming a source electrode and a drain electrode on the gate insulation layer and the oxide active layer. Therefore, damage caused to the oxide active layer while forming the source and the drain electrodes may be prevented. In addition, moisture and/or hydroxyl group generated during the process of forming the oxide semiconductor device may be efficiently reduced or removed. Accordingly, the oxide semiconductor device according to example embodiments may ensure enhanced electrical characteristics such as reduction of operating current, increase of threshold voltage distribution, reduction of mobility, etc. As a result, when the oxide semiconductor device is employed in the display device such as the organic light emitting display device, the liquid crystal display device, the flexible display device, etc., the display device may have increased quality of images and also may ensure enhanced operating speed.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative, non-limiting example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.
FIGS. 1 through 6 are cross-sectional views illustrating a method of forming an oxide semiconductor device in accordance with example embodiments.
FIG. 7 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with a wavelength of an irradiated ultraviolet ray when an ultraviolet ray irradiation process is performed on the oxide semiconductor device.
FIG. 8 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with an energy density of an irradiated ultraviolet ray when an ultraviolet ray irradiation process is performed on the oxide semiconductor device.
FIG. 9 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with process time when an ultraviolet ray irradiation process and a thermal treatment process are performed on the oxide semiconductor device at the same time.
FIGS. 10 through 18 are cross-sectional views illustrating a method of manufacturing a display device in accordance with example embodiments.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Hereinafter, methods of forming oxide semiconductor devices and methods of manufacturing display devices having oxide semiconductor devices in accordance with example embodiments will be explained in detail with reference to the accompanying drawings.
It will be understood that although the terms “first” and “second” are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element, and similarly, a second element may be termed a first element without departing from the teachings of this disclosure.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers.
In the drawings, the sizes and the thicknesses of layers and regions are exaggerated for convenience of explanation, and thus the sizes and the thicknesses are not limited thereto.
FIGS. 1 through 6 are cross-sectional views illustrating a method of forming an oxide semiconductor device in accordance with example embodiments.
Referring to FIG. 1 , a buffer layer 120 may be formed on a first face (e.g. the surface that faces upward in FIG. 1 ) of a substrate 110 . The substrate 110 may include a transparent insulation substrate. For example, the substrate 110 may include a glass substrate, a transparent resin substrate, a transparent metal oxide substrate, etc.
The buffer layer 120 may prevent diffusion of impurities from the substrate 110 . In addition, the buffer layer 120 may enhance flatness of the surface of the substrate 110 . When the substrate 110 has a relatively irregular surface, the buffer layer 120 may enhance a flatness of the surface of the first substrate 10 . Furthermore, in a case that the buffer layer 120 is formed on the substrate 110 , a gate electrode 130 may be more easily formed because stress generated while forming the gate electrode 130 may be decreased by the buffer layer 120 . The buffer layer 120 may be formed using a silicon compound. For example, the buffer layer 120 may include silicon oxide (SiOx), silicon oxycarbide (SiOxCy), etc. These may be used alone or in any mixture thereof. The buffer layer 120 may have a single layer structure or a multi layer structure including the silicon compound.
The gate electrode 130 may be formed on the buffer layer 120 . The gate electrode 130 may be connected to a gate line of a display device including the oxide semiconductor device. The gate electrode 130 may include metal, alloy, conductive metal oxide, a transparent conductive material, etc. For example, the gate electrode 130 may be formed using any of aluminum (Al), alloy containing aluminum, aluminum nitride (AlNx), silver (Ag), alloy containing silver, tungsten (W), tungsten nitride (WNx), copper (Cu), alloy containing copper, nickel (Ni), alloy containing nickel, chrome (Cr), molybdenum (Mo), alloy containing molybdenum, titanium (Ti), titanium nitride (TiNx), platinum (Pt), tantalum (Ta), tantalum nitride (TaNx), neodymium (Nd), scandium (Sc), strontium ruthenium oxide (SrRuxOy), zinc oxide (ZnOx), indium tin oxide (ITO), tin oxide (SnOx), indium oxide (InOx), gallium oxide (GaOx), indium zinc oxide (IZO), etc. These may be used alone or in any combination thereof.
Referring to FIG. 2 , a gate insulation layer 140 may be formed on the buffer layer 120 to cover the gate electrode 130 . The gate insulation layer 140 may include a silicon compound, metal oxide, etc. For example, the gate insulation layer 140 may be formed using any of silicon oxide, silicon nitride, silicon oxynitride (SiOxNy), aluminum oxide (AlOx), tantalum oxide (TaOx), hafnium oxide (HfOx), zirconium oxide (ZrOx), titanium oxide (TiOx), etc. These may be used alone or in any combination thereof. In addition, the gate insulation layer 140 may have a single layer structure or a multi layer structure including the silicon compound and/or the metal oxide.
Referring to FIG. 3 , a semiconductor layer (not illustrated) may be formed on the gate insulation layer 140 , and then the semiconductor layer may be patterned to form an active pattern (e.g., active layer) 150 . In example embodiments, the active pattern 150 include a binary compound (ABx) containing indium (In), zinc (Zn), gallium (Ga), tin (Sn), titanium (Ti), aluminum (Al), halfnium (Hf), zirconium (Zr), magnesium (Mg), etc., a ternary compound (ABxCy), for example, including such elements, or a quaternary compound (ABxCyDz), for example, including such elements, etc. For example, the active pattern 150 may include any of indium-gallium-zinc oxide (IGZO), gallium zinc oxide (GaZnxOy), indium tin oxide (ITO), indium zinc oxide (IZO), zinc magnesium oxide (ZnMgxOy), zinc tin oxide (ZnSnxOy), zinc zirconium oxide (ZnZrxOy), zinc oxide (ZnOx), gallium oxide (GaOx), titanium oxide (TiOx), tin oxide (SnOx), indium oxide (SnOx), indium-gallium-hafnium oxide (IGHO), tin-aluminum-zinc oxide (TAZO), indium-gallium-tin oxide (IGSO), etc. These may be used alone or in any combination thereof. In some example embodiments, the active pattern 150 may include a semiconductor oxide doped with any of lithium (Li), sodium (Na), manganese (Mn), nickel (Ni), palladium (Pd), copper (Cu), carbon (C), nitrogen (N), phosphorus (P), titanium, zirconium, vanadium (V), rubidium (Ru), germanium (Ge), tin, fluorine (F), etc. These may be used alone or in any mixture thereof. The active pattern 150 may have a single layer structure or a multi layer structure including the semiconductor oxide.
Referring to FIG. 4 , a source electrode 160 and a drain electrode 170 may be formed on the gate insulation layer 140 and the active pattern 150 . In example embodiments, an electrode layer (not illustrated) may be formed on the gate insulation layer 140 and the active pattern 150 , and then a mask (not illustrated) may be formed over the electrode layer. Here, the electrode layer may be patterned to form the source electrode 160 and the drain electrode 170 separated from each other by a predetermined distance substantially centering the active pattern 150 . The source electrode 160 and the drain electrode 170 may extend on the gate insulation layer 140 and may expose a central portion of the active pattern 150 (e.g., neither the source electrode 160 nor the drain electrode 170 is formed on the central portion of the active pattern 150 ).
Each of the source electrode 160 and the drain electrode 170 may be formed using any of metal, alloy, metal nitride, conductive metal oxide, a transparent conductive material, etc. For example, the source electrode 160 and the drain electrode 170 may be formed using any of aluminum, copper, molybdenum, titanium, chrome, tantalum, tungsten, neodymium, scandium, an alloy thereof, a nitride thereof, strontium ruthenium oxide, indium tin oxide, indium zinc oxide, zinc oxide, tin oxide, carbon nano tube (CNT), etc. These may be used alone or in any combination thereof. In addition, each of the source electrode 160 and the drain electrode 170 may have a single layer structure or a multi layer structure including any of the metal, the alloy, the metal nitride, the conductive metal oxide, the transparent conductive material, etc.
In a conventional method of forming a source electrode and a drain electrode of an oxide semiconductor device, damage to an active pattern may be caused during a process in which the electrode layer for forming the source electrode and the drain electrode are patterned because a metal thin film may be patterned as the electrode layer using plasma and/or an etchant. When the damage to the active pattern is generated, electrical characteristics of the oxide semiconductor device, such as operating current, threshold voltage distribution, mobility, etc. may be degraded because of the damage to the active pattern. Although the conventional method of forming the oxide semiconductor device may perform an ultraviolet ray irradiation process under an air atmosphere using an ultraviolet ray to improve electrical characteristics of the active pattern, the conventional ultraviolet ray irradiation process may not sufficiently enhance the electrical characteristic of the active pattern because the threshold voltage distribution may be easily shifted even if the ultraviolet ray is irradiated for a short irradiation time.
In example embodiments, as illustrated in FIG. 5 , an ultraviolet ray irradiation process in which an ultraviolet ray is irradiated onto a first face of the substrate 110 (e.g., the top surface in FIG. 5 ), and also a thermal treatment process in which a heat is applied to a second face of the substrate 110 (e.g., the bottom surface in FIG. 5 ) opposed to the first face of the substrate 110 may be performed at the same time. For example, the ultraviolet ray irradiation process may be carried out for about 10 second to about 1 hour using an ultraviolet ray having a wavelength between about 185 nm and about 370 nm and an energy density less than about 254 mW/cm 2 . In this case, the ultraviolet ray may be generated from an ultraviolet ray lamp or a short wavelength light emitting diode (LED). The thermal treatment process may be executed under an atmosphere including air, oxygen, ozone, nitrogen, or argon. In addition, the thermal treatment process may be performed at a temperature less than about 400° C. for about 10 second to about 1 hour. For example, the thermal treatment process may be carried out after that the substrate 110 may be disposed on a hot plate or the substrate 110 may be loaded in a furnace. Thus, the active pattern 150 may be cured, so that damage to the active pattern 150 generated in forming of the source electrode 160 and the drain electrode 170 may be efficiently reduced or removed. Furthermore, moisture and/or hydroxyl group at a surface of the active pattern 150 generated while forming the source and the drain electrodes 160 and 170 may be efficiently reduced or removed. Accordingly, the oxide semiconductor device may have enhanced electrical characteristics.
In example embodiments, the ultraviolet ray irradiation process may be performed on the second face of the substrate 110 (e.g., the bottom surface in FIG. 5 ), and the thermal treatment process may be executed on the first face of the substrate 110 (e.g., the top surface in FIG. 5 ). In some example embodiments, the ultraviolet ray irradiation process and the thermal treatment process may be simultaneously performed on the first and the second faces of the substrate 110 . Therefore, electrical characteristics of the oxide semiconductor device may be efficiently improved.
In one embodiment, the ultraviolet ray irradiation process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 . In another embodiment, the ultraviolet ray irradiation process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 . In one embodiment, the thermal treatment process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 . In another embodiment, the thermal treatment process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 .
In one embodiment, the ultraviolet ray irradiation process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 , and the thermal treatment process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 . In another embodiment, the ultraviolet ray irradiation process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 , and the thermal treatment process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 . In one embodiment, the ultraviolet ray irradiation process is performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 , and the thermal treatment process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 . In another embodiment, the ultraviolet ray irradiation process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 , and the thermal treatment process is performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 . In one embodiment, the ultraviolet ray irradiation process and the thermal treatment process are both performed on the first surface (e.g., top surface in FIG. 5 ) of the substrate 110 . In another embodiment, the ultraviolet ray irradiation process and the thermal treatment process are both performed on the second surface (e.g., bottom surface in FIG. 5 ) of the substrate 110 .
Referring to FIG. 6 , an etching stop layer 180 may be formed on the active pattern 150 exposed by the source electrode 160 and the drain electrode 170 . For example, the etching stop layer 180 may be formed using any of silicon oxide, silicon nitride, silicon oxynitride, semiconductor oxide, etc. These may be used alone or in any combination thereof.
A protection layer 190 may be formed on the gate insulation layer 140 to cover the source electrode 160 , the drain electrode 170 , and the etching stop layer 180 . For example, the protection layer 190 may include any of silicon oxide, silicon nitride, silicon oxynitride, etc.
In the oxide semiconductor device described with reference to FIG. 6 , the oxide semiconductor device may have a bottom gate construction in which the gate electrode 130 is disposed under the active pattern 150 . However, the construction of the oxide semiconductor device may not be limited thereto. For example, the oxide semiconductor device may have a top gate construction in which the gate electrode 130 is disposed on the active pattern 150 .
FIG. 7 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with a wavelength of an irradiated ultraviolet ray when an ultraviolet ray irradiation process is performed on the oxide semiconductor device.
Referring to FIG. 7 , ultraviolet rays having different wavelengths (e.g., about 185 nm and about 365 nm) were irradiated onto an oxide semiconductor device for about 30 minutes. In this case, the mobility of the oxide semiconductor device onto which an ultraviolet ray having a wavelength of about 185 nm was irradiated was higher than the mobility of the oxide semiconductor device onto which an ultraviolet ray having a wavelength of about 365 nm. In addition, the threshold voltage distribution of the oxide semiconductor device onto which an ultraviolet ray having the wavelength of about 185 nm was irradiated was lower than the threshold voltage distribution of the oxide semiconductor device onto which an ultraviolet ray having the wavelength of about 365 nm. Therefore, it may be appropriate that an ultraviolet ray irradiation process may be performed using an ultraviolet ray having a wavelength between about 185 nm and about 370 nm.
FIG. 8 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with an energy density of an irradiated ultraviolet ray when an ultraviolet ray irradiation process is performed on the oxide semiconductor device.
Referring to FIG. 8 , ultraviolet rays having different energy densities (e.g., about 64 mW/cm 2 and about 254 mW/cm 2 ) were irradiated onto an oxide semiconductor device for about 30 minutes. In this case, the mobility of the oxide semiconductor device onto which an ultraviolet ray having an energy density of about 64 mW/cm 2 was irradiated was lower than the mobility of the oxide semiconductor device onto which an ultraviolet ray having an energy density of about 254 mW/cm 2 . Further, the threshold voltage distribution of the oxide semiconductor device onto which an ultraviolet ray having the energy density of about 64 mW/cm 2 was irradiated was higher than the threshold voltage distribution of the oxide semiconductor device onto which an ultraviolet ray having the energy density of about 254 mW/cm 2 . Therefore, it may be appropriate that an ultraviolet ray irradiation process may be performed using an ultraviolet ray the having an energy density less than about 254 mW/cm 2 .
FIG. 9 is a graph illustrating the transfer characteristic of an oxide semiconductor device in accordance with process time when an ultraviolet ray irradiation process and a thermal treatment process are performed on the oxide semiconductor device at the same time.
Referring to FIG. 9 , an ultraviolet ray irradiation process and a thermal treatment process were simultaneously executed on the oxide semiconductor device for different process times. Here, the thermal treatment process was performed under an atmosphere including air at a temperature less than about 200° C., and the ultraviolet ray irradiation process was carried out using an the ultraviolet ray having a wavelength of about 365 nm and an energy density having about 254 mW/cm 2 .
Table 1 shows mobilities of oxide semiconductor devices and threshold voltage distributions of oxide semiconductor devices in accordance with Comparative Example, Example 1, Example 2, Example 3, and Example 4.
TABLE 1
Mobility of an oxide
Threshold voltage
semiconductor
distribution of an oxide
No
device (cm 2 /vs)
semiconductor device (V)
Comparative
4.84
5.98
Example
Example 1
8.47
2.16
Example 2
9.02
1.64
Example 3
11.92
0.76
Example 4
10.71
1.69
Example 1
An ultraviolet ray having a wavelength of about 365 nm and an energy density of about 254 mW/cm 2 was irradiated onto an oxide semiconductor device for about 10 minutes while heating the oxide semiconductor device for about 10 minutes under an air atmosphere at a temperature of about 200° C.
Example 2
An ultraviolet ray having a wavelength of about 365 nm and an energy density of about 254 mW/cm 2 was irradiated onto an oxide semiconductor device for about 20 minutes while heating the oxide semiconductor device for about 20 minutes under an air atmosphere at a temperature of about 200° C.
Example 3
An ultraviolet ray having a wavelength of about 365 nm and an energy density of about 254 mW/cm 2 was irradiated onto an oxide semiconductor device for about 30 minutes while heating the oxide semiconductor device for about 30 minutes under an air atmosphere at a temperature of about 200° C.
Example 4
An ultraviolet ray having a wavelength of about 365 nm and an energy density of about 254 mW/cm 2 was irradiated onto an oxide semiconductor device for about 1 hour while heating the oxide semiconductor device for about 1 hour under an air atmosphere at a temperature of about 200° C.
Comparative Example
An ultraviolet ray irradiation process and a thermal treatment process were not performed on an oxide semiconductor device.
As illustrated in FIG. 9 , the mobilities of the oxide semiconductor devices in accordance with Example 1 to Example 3 were gradually increased from Example 1 to Example 3, and the threshold voltage distributions of the oxide semiconductor devices in accordance with Example 1 to Example 3 were gradually decreased from Example 1 to Example 3. As the process times of the ultraviolet ray irradiation process and the thermal treatment process was further increased, electrical characteristics of the oxide semiconductor device were more enhanced. In the case that the ultraviolet ray irradiation process and the thermal treatment process were performed for about 30 minutes, the electrical characteristics of the oxide semiconductor device were efficiently improved. However, in Example 4, the mobility of the oxide semiconductor device was decreased, and the threshold voltage distribution of the oxide semiconductor device was increased. Accordingly, it may be appropriate that the ultraviolet irradiation process and the thermal treatment process may be performed for about 1 hour. That is, when an ultraviolet ray was irradiated onto the oxide semiconductor device for about 1 hour while heating the oxide semiconductor device for about 1 hour under an air atmosphere at a temperature of about 200° C., the electrical characteristics of the oxide semiconductor devices were efficiently enhanced.
FIGS. 10 through 18 are cross-sectional views illustrating a method of manufacturing a display device in accordance with example embodiments.
Referring to FIG. 10 , a gate electrode 230 may be formed on a substrate 210 . For example, a conductive layer (not illustrated) may be formed on the substrate 210 , and then the conductive layer may be patterned to form the gate electrode 230 .
Referring to FIG. 11 , a gate insulation layer 240 may be formed on the substrate 210 to cover the gate electrode 230 . In example embodiments, the gate insulation layer 240 may have a relatively thick thickness to sufficiently cover the gate electrode 230 . In some example embodiments, the gate insulation layer 240 having a substantially uniform thickness may be formed on the gate insulating layer 200 along a profile of the gate electrode 230 . In some example embodiments, the gate insulation layer 240 having a relatively thin thickness may be formed on the gate insulating layer 200 along the profile of the gate electrode 230 .
Referring to FIG. 12 , an active pattern 250 may be formed on the gate insulation layer 240 . In example embodiments, the active pattern 250 may be formed using a semiconductor oxide.
Referring to FIG. 13 , an electrode layer (not illustrated) may be formed on the gate insulation layer 240 and the active pattern 250 . The electrode layer may be substantially uniformly formed on the gate insulation layer 240 and the active pattern 250 . The electrode layer may be patterned to form a source electrode 260 and a drain electrode 270 . The source electrode 260 and the drain electrode 270 may be separated from each other by a predetermined distance substantially centering the active pattern 250 . The source electrode 260 and the drain electrode 270 may extend on the gate insulation layer 240 .
In the conventional method of forming a source electrode and a drain electrode of an oxide semiconductor device, damage to an active pattern may be caused while forming the source electrode and the drain electrode. When the damage to the active pattern may cause deterioration of electrical characteristics of the oxide semiconductor device, such as reduction of operating current, increase of threshold voltage distribution, reduction of mobility, etc. Although the conventional method of forming the oxide semiconductor device may include an ultraviolet ray irradiation process performed under an air atmosphere using an ultraviolet ray to enhance electrical characteristics of the active pattern, the conventional ultraviolet ray irradiation process may not sufficiently enhance the electrical characteristics of the active pattern because the threshold voltage distribution may be easily shifted even if the ultraviolet ray is irradiated for a short irradiation time. As a result, when the oxide semiconductor device is employed in the display device such as the organic light emitting display device, the liquid crystal display device, the flexible display device, etc., the display device including the oxide semiconductor device may have poor quality of images and relatively slow operating speed.
Considering these problems, as illustrated in FIG. 14 according to example embodiments, an ultraviolet ray irradiation process in which an ultraviolet ray may be irradiated onto the first face of the substrate 210 , and simultaneously a thermal treatment process in which a heat may be applied to a second face of the substrate 210 opposed to the first face of the substrate 210 . For example, the ultraviolet ray irradiation process may be performed for about 10 second to about 1 hour using an ultraviolet ray having a wavelength between about 185 nm and about 370 nm and an energy density less than about 254 mW/cm 2 . In this case, the ultraviolet ray may be generated from an ultraviolet ray lamp or a short wavelength light emitting diode (LED). The thermal treatment process may be executed under an atmosphere including air, oxygen, ozone, nitrogen, or argon. In addition, the thermal treatment process may be carried out at a temperature less than about 400° C. for about 10 second to about 1 hour. The thermal treatment process may be performed using a hot plate or a furnace.
In some example embodiments, the ultraviolet ray irradiation process may be performed on the second face of the substrate 210 , and the thermal treatment process may be executed about the first face of the substrate 210 . In other example embodiments, the ultraviolet ray irradiation process and the thermal treatment process may be performed on the first and the second faces of the substrate 210 at the same time. Thus, the active pattern 250 may be cured, so that damage to the active pattern 250 generated in forming of the source electrode 260 and the drain electrode 270 may be efficiently reduced or removed. Additionally, moisture and/or hydroxyl group at a surface of the active pattern 250 generated while forming the source electrode 260 and the drain electrode 270 may be efficiently reduced or removed. Accordingly, the oxide semiconductor device may ensure enhanced electrical characteristics.
Referring to FIG. 15 , an etching stop layer 280 may be formed on the active pattern 250 exposed by the source electrode 260 and the drain electrode 270 . For example, the etching stop layer 280 may be formed using any of silicon oxide, silicon nitride, silicon oxynitride, semiconductor oxide, etc.
A protection layer 290 may be formed on the gate insulation layer 240 to cover the source electrode 260 , the drain electrode 270 , and the etching stop layer 280 . For example, the protection layer 290 may include any of silicon oxide, silicon nitride, silicon oxynitride, etc.
Accordingly, the oxide semiconductor device including the gate electrode 230 , the gate insulation layer 240 , the active pattern 250 , the source electrode 260 , the drain electrode 270 , the etching stop layer 280 , and the protection layer 290 may be formed on the substrate 210 .
Referring to FIG. 16 , an insulation layer 300 may be formed on the substrate 210 to cover the oxide semiconductor device. For example, the insulation layer 300 may be formed using a transparent insulation material. In example embodiments, a planarization process may be executed on the insulation layer 300 to enhance the flatness of an upper surface of the insulation layer 300 .
Referring to FIG. 17 , the insulation layer 300 may be partially etched to form a hole partially exposing the drain electrode 270 . The hole of the insulation layer 300 may be formed by a photolithography process.
A first electrode layer (not illustrated) may be formed on the insulation layer 300 . The first electrode layer may be formed on the drain electrode 270 and the insulation layer 300 along a profile of the insulation layer 300 . The first electrode layer may have a substantially uniform thickness. The first electrode layer may include any of a transparent conductive material, a semi-transparent conductive material, a reflective conductive material, etc.
The first electrode layer may be patterned to form a first electrode 310 connected to the drain electrode 270 . In this case, the first electrode 310 may correspond to a pixel electrode of the display device. The first electrode 310 may be formed on an exposed drain electrode 270 , a sidewall of the hole, and the insulation layer 300 .
A pixel defining layer 320 may be formed on the first electrode 310 . In example embodiments, the pixel defining layer 320 may be formed using a transparent insulating material. For example, the pixel defining layer 320 may be formed using any of an organic material (e.g., polyacryl-based resin, polyimide-based resin, etc.), a silica-based inorganic material, etc.
The pixel defining layer 320 may be partially etched to form an opening that exposes the first electrode 310 . For example, the opening may have a sidewall inclined by a predetermined angle relative to the substrate 210 . Thus, an organic light emitting layer 330 and/or a second electrode 340 (e.g., as shown in FIG. 18 ) may be subsequently easily formed in accordance with the predetermined angle of the sidewall of the opening.
As illustrated in FIG. 18 , an organic light emitting layer 330 may be formed on the first electrode 310 , the sidewall of the opening, and the pixel defining layer 320 . The organic light emitting layer 330 may be formed on a first electrode 310 exposed along a profile of the opening, the sidewall of the opening, and the pixel defining layer 320 . The organic light emitting layer 330 may include low molecular organic materials, high molecular inorganic materials generating a red color of light, a material generating a green color of light or a material generating a blue color of light. Additionally, the organic light emitting layer 330 may have a multi-layer structure, which may include any of a hole injection layer, a hole transfer layer, an emitting layer, an electron transfer layer, an electron injection layer, etc.
A second electrode 340 may be formed on the organic light emitting layer 330 . The second electrode 340 may include any of a transparent conductive material, a semi-transparent conductive material, a reflective conductive material, etc. The second electrode 340 may be formed on the organic light emitting layer 330 . In some example embodiments, when the organic light emitting layer 330 is formed on only the first electrode 310 , the second electrode 340 may be formed in only the opening of the pixel defining layer 320 . For example, the organic light emitting layer 330 may be formed on only the first electrode 310 and the sidewall of the opening, and the second electrode 340 may be formed on the organic light emitting layer 330 . For example, a second electrode layer may be formed on the organic light emitting layer 330 and the pixel defining layer 320 , and then the second electrode layer may be patterned to form the second electrode 340 .
A second substrate 350 opposed to the substrate 210 (e.g., on the opposite side of the substrate 210 as shown in FIG. 18 ) may be provided over the second electrode 340 . For example, the second substrate 350 may include a transparent insulation material.
As illustrated above, the display device may include the oxide semiconductor device having enhanced electrical characteristics, so that the display device may have increased quality of images and enhances operating speed.
According to example embodiments, an ultraviolet ray irradiation process and a thermal treatment process may be simultaneously performed after forming of a source electrode and a drain electrode. Thus, damage caused to an active pattern while forming the source and the drain electrodes may be prevented. In addition, moisture and/or hydroxyl group generated in process of forming the oxide semiconductor device may be efficiently reduced or removed. Accordingly, the oxide semiconductor device according to example embodiments may ensure enhanced electrical characteristics such as reduction of operating current, increase of threshold voltage distribution, reduction of mobility, etc. As a result, when the oxide semiconductor device is employed in the display device such as the organic light emitting display device, the liquid crystal display device, the flexible display device, etc., the display device may have increased quality of images and enhanced operating speed.
The foregoing is illustrative of example embodiments and is not to be construed as limiting thereof. Although a few example embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages of the present inventive concept. Accordingly, all such modifications are intended to be included within the scope of the present inventive concept as defined in the claims. Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and is not to be construed as limited to the specific example embodiments disclosed, and that modifications to the disclosed example embodiments, as well as other example embodiments, are intended to be included within the scope of the appended claims.
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A method of forming an oxide semiconductor device may be provided. In the method, a substrate comprising a first major surface and a second major surface that faces away from the first major surface may be provided. An oxide semiconductor device may be formed over the first major surface to provide an intermediate device, and the semiconductor device may comprise an oxide active layer. The intermediate device may be subjected to ultraviolet (UV) light (e.g., ultraviolet ray irradiation process) for a first period, and subjected to heat (e.g., thermal treatment process) for a second period. The first and second periods may at least partly overlap.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to the field of automatic animal feeding and watering devices.
[0003] 2. Description of Related Art
[0004] Animals cared for in a commercial setting, such as dogs owned by security companies, tend to benefit from multiple caretakers with sufficient human presence to ensure feed and water are delivered on time and in the quantities required. Pet owners, however, may not always be able to deliver this quality care either due to schedule or vacation. This poses a significant problem especially when the dog serves the dual purpose of being a pet and a guard of the property.
[0005] It is not feasible to remove the dog and place him in a shelter or by a friend since the property remains unguarded. The alternative entails getting someone familiar with the animal to attend to its dietary needs on a daily basis. This can prove quite challenging especially if the dog is temperamental and dangerous. The other limitation of this approach is that it allows others to be familiar with the property guard and poses a security risk.
[0006] Several patents have been filed to address the problem of animal feeding, however, they do fall short in one area or another.
[0007] There are several approaches to the metering and delivery of dry food. One of the simplest means is a basic flap opening under a hopper that is actuated by a solenoid or motor as presented in U.S. Pat. Nos. 4,733,634, 5,794,560 and 6,196,158. This system is simple but the likelihood of sealing the opening once it is opened is low since food pellets will inevitably become lodged between the sealing plate and hopper. In addition to this it is unlikely the same quantity of food will be reliably delivered when the hopper is full as opposed to nearly empty.
[0008] Rotating slotted disks have found favor with some designers. They work on the principle that a specified amount of food is captured and transported per rotation. Good examples of this approach are presented in U.S. Pat. Nos. 4,292,930, 4,324,203 and 6,427,628. These systems are relatively accurate but incur shear planes as they rotate. Should a food pellet become lodged at this interface two possible scenarios can occur; the pellet can be crushed or the mechanism can fail. Neither occurrence is of benefit with the consequences ranging from compromising the integrity and quantity of food delivered to a complete lack of food delivery and possible equipment damage. Should the food be crushed high vibration and wear on the equipment can be expected which will surely impact negatively on its useful life.
[0009] Rotating blade systems have also been proposed utilizing inflexible blades that direct feed either inward as illustrated in U.S. Pat. Nos. 4,020,980, 5,622,467 and 6,681,718 or outward, as illustrated in U.S. Pat. No. 4,513,688. These systems do eliminate the shear planes previously described. They are, however, incapable of providing an effective vapor seal and as such allow atmospheric humidity to compromise the integrity of the stored feed. This lack of seal also allows vermin to get into the feed.
[0010] Water pumps have been proposed to circulate water from a reservoir through filter media and into a consumption receptacle thereby improving the quality of water delivered to an animal. Good examples of this approach are seen in U.S. Pat. Nos. 7,762,211 and 6,928,954. While this method has its benefits it does not solve the problem of disposing of the organic particulate matter that collects in the water as an animal consumes. Instead of disposal the particulate matter is trapped in a filter and as such contaminates the water as it decomposes.
SUMMARY OF THE INVENTION
[0011] The present invention described is a device catering for the dietary needs of animals. Feed is stored in a hopper and distributed at intervals to the animal's feeding receptacle via an internal dispensing mechanism using a flexible rotor sealing against the walls of a housing to both meter the feed and seal against contamination. The quantities and delivery times may be set by the user. An optional weighting system can be provided to increase accuracy of delivered feed amounts.
[0012] Optionally, the device may include a water delivery system. Water is provided by a plumbed domestic connection and is available to the animal at all times, except during the automatic change cycle. A pump is utilized to change the water several times a day, in an attempt to remove any contaminants that may affect the water quality that is required to be dispensed.
BRIEF DESCRIPTION OF THE DRAWING
[0013] FIG. 1 is a frontal perspective view of the preferred embodiment of the present invention with the lid cover open.
[0014] FIG. 2 is a rear perspective view of the preferred embodiment of the present invention.
[0015] FIG. 3 is a fragmentary perspective view of the preferred embodiment of the present invention.
[0016] FIG. 4 is a cross-sectional view of the present invention, taken perpendicular to the frontal face and through the centre line of the apparatus.
[0017] FIG. 5 is a cross-sectional view of the feed delivery mechanism, of the present invention, excluding the hopper, chutes and weighting system, taken perpendicular to the frontal face and through the centre line of the hopper.
[0018] FIG. 6 a is an exploded fragmentary perspective view of the feed delivery mechanism of the present invention, showing the rotor and associated housing components.
[0019] FIG. 6 b is an exploded fragmentary perspective view of the feed delivery system of the present invention, inclusive of the motor and chute to the weighting system.
[0020] FIG. 7 is a fragmentary perspective view of the feed delivery system of the present invention.
[0021] FIG. 8 is cross-sectional view of the apparatus of the present invention, taken parallel to the frontal face and through the centre of the hopper exit.
[0022] FIG. 9 is a perspective view of the feed weighting system of the present invention.
[0023] FIG. 10 a is an underside view of the weighting system of the present invention, with the release gate closed.
[0024] FIG. 10 b is an underside view of the weighting system of the present invention, with the release gate open.
[0025] FIG. 11 a is a side view of the weighting system of the present invention, as it would appear with no feed material present.
[0026] FIG. 11 b is a side view of the weighting system of the present invention, as it would appear when filled with feed material.
[0027] FIG. 12 a is a fragmentary perspective view of the present invention's weighting system's pivotal shaft and support bearings.
[0028] FIG. 12 b is a fragmentary perspective view of the present invention's weighting system's release gate showing the motor, coupling, limit switches and physical stop.
[0029] FIG. 13 is a fragmentary perspective view of the complete weighting system of the present invention.
[0030] FIG. 14 a is a sectional view of the rotor of the present invention, perpendicular to its length depicting the deflection of the splines, as they rotate within the confines of the housing.
[0031] FIG. 14 b is a perspective view of the rotor of the present invention, illustrating the wiper fins that clean the mechanism's housing during regular operation.
[0032] FIG. 15 is an overhead view of the watering system of the present invention.
[0033] FIG. 16 is a cross-sectional view of the watering system of the present invention, taken parallel to the front face of the apparatus and through the centre line of the water bowl and feed receptacle.
[0034] FIG. 17 shows a modular electrical layout for the present invention.
[0035] FIG. 18 shows a modular plumbing layout for the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Although a specific embodiment of the present invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and merely illustrative of but a small number of the many possible specific embodiments which can represent applications of the principles of the present invention.
[0037] Various changes and modifications, apparent to one skilled in the art, to which the present invention pertains, are deemed to be within the spirit, scope and contemplation of the present invention as further defined in the appended claims.
[0038] For the preferred embodiment of the present invention, the front 20 has an indented face to accommodate the animal during feeding. The feed 66 and water bowls 67 are located on a level platform created within the indented face. The chute shield 65 that covers the feed exit chute 64 (not shown) is visible. This piece is a finisher and serves in a solely aesthetic role.
[0039] The top access cover 24 is shown in an open position. As such the user interface, inclusive of the liquid crystal display 75 and keypad 76 , is visible. One side of the cover latch 26 , used to secure the top access cover against the rubber seal 30 , is also visible. The force provided by the latch ensures a reliable seal is formed and maintained. This is important to ensure the integrity of the pelletized feed is not compromised due to exposure to the atmosphere. The cover latch 26 also allows the option to lock the device. Two sides of the hopper 31 are also visible from this angle. The open cover limit switch 81 is also indicated though it is barely visible due to scale.
[0040] A rear perspective view of the apparatus of the present invention shows the electrical connection 77 , which utilizes a gland 78 , to facilitate safe cable penetration through the rear body panel 21 . The water supply connection 71 and drain connection 72 are also visible. The final items shown on the rear panel 21 are two part mounting brackets 27 , 28 .
[0041] One part of the wall mount bracket 27 mounts on to the rear body panel 21 while the other part 28 mounts on to a secure surface such as a wall. These mounting brackets 27 , 28 ensure that the only way to move the device is by lifting, a task nearly impossible for any domestic animal. The hinges 23 for the top access cover 24 and the handles 25 are visible, as is the entire latch 26 , shown in a locked position.
[0042] A cutaway perspective view of the apparatus of the present invention provides a good basis for understanding the spatial coordination between the independent systems and is best referenced as these systems are described in detail.
[0043] In a section taken perpendicular to the front face 20 , the latch 26 is shown in a closed position securing the top access cover 24 against the rubber seal 30 , as mentioned previously. The liquid crystal display 75 , circuit board 80 and transformer 79 are also visible. The delivery mechanism housing top ring 32 is included to allow some compliance between the hopper 31 and delivery mechanism thus allowing some flexibility in manufacturing. This arrangement ensures no pelletized feed escapes even if there is a small gap. Due to scale many components in the delivery mechanism are not clearly visible and as such an enlarged view of this system is provided in FIG. 5 . The delivery system motor 50 and delivery motor mount plate 48 are labeled to reference the system. The placement of the section avoids much of the components in the weighting system and as such those shown appear to be floating.
[0044] For reference the scale pillow bearings 59 and scale release gate motor 57 are identified. The internal frame 83 was transected at several points and shows up as squares on the drawing. The water tank 68 is visible but this view provides little information. Finally it is noted that the bottom body panel 22 is shown with the frame bolted to it to transfer the weight of the supported components to the floor.
[0045] An enlarged view of the present invention shows the sectioned feed delivery system, excluding the hopper 31 and delivery system chute 51 . Upon activation by the microprocessor controller 80 the delivery system motor 50 activates the rotor 39 via a rotor shaft 40 and three piece coupling system 45 , 46 , 47 . The first piece of the coupling 47 is attached to the delivery system motor 50 shaft. The other piece 45 is attached to the rotor shaft 40 . Mechanical coupling is achieved via a key 46 . This arrangement allows for easy separation of the coupling and facilitates assembly and disassembly.
[0046] As is good practice, the rotor shaft 40 is supported at both ends by bushings 41 , 42 which are in turn kept in position by housings 43 , 44 . Lateral movement of the rotor shaft 40 is restricted by a small lip on the shaft that allows bushing 42 to function as a thrust bushing. Movement in the opposite direction is prevented by the thrust bushing internal to the delivery system motor 50 . The shape of the upper portion of the delivery system chute 51 allows it to form a seal against the curved portion of the mechanism's housing 34 .
[0047] A sectional view taken parallel to the front of the device, through the centerline of the exit port of the hopper 31 , is provided in FIG. 8 . This view transects the feed distribution and weighing mechanisms in a direction that facilitates an explanation of the principle of operation of these systems. The loading of feed is performed by opening the top access cover 24 and filling the hopper 31 .
[0048] The pelletized feed is conveyed into the delivery mechanism via gravity flow, but will be restricted from flowing into the delivery system chute 51 by the sealing action of the flexible rotor 39 against the curved walls of the delivery mechanism housing 34 . Tests show the angle of the hopper 31 walls must be in excess of thirty five degrees to the horizontal and the hopper must be manufactured with a smooth finish, plastic being the material of choice, to ensure pelletized feed on the market will flow unassisted by vibration or any other means. The size of the exit from the hopper is also important and is preferably of the order of sixty five millimeters (approximately two and a half inches) to ensure free flow.
[0049] Rotation of the flexible rotor 39 , by means of a delivery system motor 50 (not shown), moves an approximate quantity of feed per angular displacement to the bottom opening cut into the curved delivery mechanism housing 34 . The feed falls by gravity into the delivery system chute 51 which must be maintained at above thirty five degrees to the horizontal to guarantee movement of the pelletized feed.
[0050] The delivered quantity per complete rotation is largely a factor of the geometry of the flexible rotor 39 and the curved portion of the mechanism housing 34 . Pellet size and packing due to weight from above are also factors that affect accuracy. To increase the accuracy a weighting system is included.
[0051] The weighting system is based on the commonly used method of relating the extension of a spring to the force exerted once it is within its linear range. The scale basket 52 collects the feed via the delivery system chute 51 . In the initial stages the scale release gate 54 is kept closed so the feed fills the basket 52 . As this occurs, the basket 52 pivots about the scale pivot shaft 58 and with the weight of the feed being balanced by the force exerted by the extension of the scale counterbalance spring device 63 as illustrated in FIGS. 11 a and 11 b.
[0052] To achieve reasonable accuracy the spring constant, k, of the scale counterbalance spring device 63 must be relatively low. This would not be very accurate if the scale counterbalance spring device 63 had to support the weight of the scale balance assembly (scale basket 52 , scale release gate actuator 57 , scale release gate 54 and other devices on that side of the scale pivot shaft 58 ). A counter balance 61 is included to solve this problem with weights 62 added to perfectly balance the system when the scale basket 52 is empty.
[0053] The accuracy of the weighting system is also affected by the resistance to rotation at the scale pivot shaft 58 . Pillow bearings 59 , visible in FIG. 9 , are specified to reduce the effects of friction.
[0054] The angular rotation is directly related to the weight of the feed in the scale basket 52 hence measuring this attribute with a measuring device allows the circuit board with microprocessor controller 80 to calculate feed portions. An optical encoder 60 was chosen as the measuring device due to its accuracy. It is noted this can be replaced by a sensitive potentiometer.
[0055] Once the desired amount of feed is measured the circuit board with microprocessor controller 80 turns off the power to the delivery system motor 50 and turns on power to the scale gate motor 57 . The scale gate motor 57 opens the scale release gate 54 until it comes in contact with the physical stop 55 . At that point a limit switch 56 is activated and the power to the scale gate release motor 57 is stopped. The system stays in this position for a short period of time to allow all the feed to fall from the scale basket 52 into the flared end of the feed exit chute 64 .
[0056] Once this is complete, the power to the scale gate release motor 57 is reversed and the scale release gate mechanism 54 is closed. Upon reaching the closed position the scale release gate mechanism 54 is prevented from further motion due to the shape of one end of the scale basket 52 . At this point another limit switch 85 is activated and power to the scale gate release motor 57 is turned off.
[0057] The open and closed positions of the scale release gate mechanism 54 and activation of the limit switches 56 , 85 mentioned are illustrated in FIG. 10 . Due to the action of the scale counterbalance spring device 63 the system will rebalance to the position status it was in prior to receiving feed.
[0058] An exploded perspective view of the pivot shaft 58 depicts pillow bearings 59 and the optical encoder 60 . It is noted the scale shaft 58 is square in the central section to facilitate mounting on to the scale basket 52 .
[0059] In an exploded perspective view of the scale gate release system inclusive of the scale gate motor 57 , scale gate motor plate 53 , the limit switches 56 , 85 and their mounts, the scale release gate physical stop 55 , the scale gate motor coupling 84 and the scale gate 54 are visible. The scale release gate motor 57 is bolted on the scale motor mount plate 53 and is connected to the scale release gate 54 via a coupling 84 . FIG. 13 provides an exploded perspective view of the entire weighting system with the two subsystems illustrated in FIG. 12 a and FIG. 12 b assembled.
[0060] It may be argued that the scale release gate 54 creates the shear plane when closing, that the flexible rotor 39 sought to avoid. This is not so, however, since the scale release gate 54 allows all pelletized feed to fall before it closes; hence there is nothing to shear. Obviously this principle cannot work when the storage is the hopper 31 .
[0061] The microprocessor controller on the circuit board 80 is programmed with a lookup table that allows it to compare the on time of the delivery system motor 50 with the estimated feed delivered. If there is significant variation between the expected delivery system motor 50 on time and appropriate feedback from the scale optical encoder 60 the system alerts the operator of an error. This would normally be due to a lack of feed in the hopper 31 , though it is possible that a motor or drive system failure would also result in triggering the alarm.
[0062] The delivery system motor 50 requires high torque to overcome resistance and a low rotation speed to allow gravity to act on the pelletized feed when it reaches the opening in the curved delivery mechanism housing 34 . A motor with integrated gearing is ideal for this application. Similarly the scale gate motor 57 requires higher torque and lower revolutions per minute to perform its task and as such a motor with integrated gearing is also specified in this application. It is noted that a powerful solenoid could be used to activate the scale release gate 54 and would replace the need for the limit switches 56 , 85 and physical stop 55 .
[0063] The successful operation as described above is highly dependent on the flexibility of the rotor 39 . If the rotor 39 is too rigid, the feed pellets will become wedged between its blades and the curved portion of the curved mechanism housing 34 .
[0064] In this scenario the feed pellets can be crushed, the delivery system motor 50 can stall or some component in the drive train can fail. This was actually tested with stainless steel blades. Under the test conditions the motor consistently stalled in less than one complete revolution. On the other hand if the impeller is too flexible, it will deflect due to the weight of the pelletized feed above it and it will allow some to pass through especially if the device is shaken. The desired flexibility is achieved partly by the shape of the rotor 39 blades and partly by the material it is fabricated from. It is also noted that the materials of choice must be of feed grade. Some types of rubber and flexible plastic seem to be best suited for this application.
[0065] FIG. 14 a is a sectional view of the mechanism housing taken perpendicular to the axis of the rotor shaft 40 and close to one end so the openings on the delivery mechanism's top plate 33 and curved plate 34 are not visible. The rotor 39 blades are curved and angled in a manner to allow them to flex easily when they are rotated in the anticlockwise direction. It is also noted that the tip of the rotor 39 blades are angled and largely flat so that they become perpendicular to the curved mechanism housing 34 when flexed as illustrated.
[0066] The inherent resilience of the material and shape of the rotor 39 blade, allows it to wipe the curved mechanism housing 34 , in a similar manner to the action of a wiper blade on a windshield. A dashed line shows the diameter of the curved mechanism housing 34 extended into the vertical portion. This helps to illustrate the slight straightening of the rotor 39 blades and thus extension above the dashed line, as they become unrestrained. It is noted that six blades were chosen so at least two will be sealing the opening at the bottom of the curved mechanism housing 34 at all times.
[0067] A perspective view of the rotor 39 alone, reveals that thin wiper style fins are included on each blade, as illustrated in FIG. 14 b , to allow the rotor 39 to wipe the flat side walls of the mechanism housing 35 , 36 . More importantly these fins ensure a thorough seal between the rotor 39 and mechanism housing 34 and thus prevent the intrusion of vermin and humidity; as such they are necessary to ensure the integrity of the pelletized feed stored in the hopper 31 . It is noted that the size of the rotor 39 was determined by the size in the exit port of the hopper 31 which is slightly above the minimum required for free flow of the pelletized feed, presently on the market, under gravity.
[0068] A top down perspective view of the water system reveals that water is supplied via a plumbed mains connection 71 to the water tank 68 under the regulation of a float valve 69 . An overflow 73 is included and plumbed to the drain connection 72 to facilitate the safe discharge of water should the float valve 69 fail. The drain connection 72 is plumbed directly to a small water pump 74 .
[0069] The discharge from this water pump 74 is elevated to a level above the water tank 68 to keep the water from flowing through the pump 74 and out the drain connection 72 via gravity. The drain connection 72 exits the device at a low level to facilitate gravity discharge from the overflow 73 . The plumbing connections described are represented in a modular format in FIG. 18 .
[0070] FIG. 16 provides a sectioned view of the water system taken through the centerline of the water 67 and feed bowls 66 . The tapered base of the water tank 68 assists in the funneling of feed particulate to the drain connection 72 . The small hole required to allow water to flow from the water tank 68 into the water bowl 67 is visible. The chute shield 65 , best illustrated in FIG. 3 , is removable allowing the feed bowl 66 to be removed for cleaning. The water tank 68 is shaped in such a manner that a partitioned portion of it, that remains dry, forms a finisher to hide the internal mechanisms of the device when the feed bowl 66 is removed for cleaning.
[0071] The wet compartment of the water tank 68 is sized as small as possible to accommodate the water bowl 67 and float valve 69 . This is important since the water is disposed of at least four times a day. The purpose of this is to minimize the feed particulate and other contaminants in the water that inevitably builds up as the animal consumes from the water bowl 67 . This approach is critical in providing a clean water supply to the animal thus ensuring good health. The cleaning process mentioned above involves the input solenoid valve 82 shutting off the mains water supply connection 71 while the water pump 74 empties the water tank 68 .
[0072] After a fixed period of time, determined empirically, the water pump 74 is turned off and the solenoid valve 82 is opened to allow the water tank 68 to refill. The process is repeated to achieve best results and thus two discharges of the water represent one cycle. The cycle is repeated four times daily as mentioned previously. Of course, the electrical control of the solenoid valve 82 and water pump 74 occurs automatically via the microprocessor controller on the circuit board 80 .
[0073] FIG. 17 provides a modular representation of the electrical system in the automatic animal feeding and watering device. The microprocessor controller on the circuit board 80 is the key element that makes the automatic functionality possible. User interface is achieved through the incorporation of a keypad 76 for input and a display 75 for feedback. Through this interface the user is guided to set the current date and time, feeding schedules and quantities.
[0074] The microprocessor controller 80 utilizes the user settings and a lookup table, based on empirical data, to determine the angular displacement, as measured by the scale optical encoder 60 , that corresponds to the volume of food desired.
[0075] The water pump 74 and solenoid valve 82 are also controlled by the microprocessor controller 80 . This action is automatic and requires no user setting. Power to the system is supplied by the mains via an electrical connection with a standard plug 77 and is regulated via a transformer 79 to the appropriate voltage for the microprocessor controller 80 .
[0076] It is pointed out that although the present invention has been shown and described with reference to a particular embodiment, nevertheless various changes and modifications, apparent to one skilled in the art to which the present invention pertains, are deemed to lie within the purview of the invention and may be seen when taken together with the accompanying drawings and the Claims.
[0077] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
REFERENCE NUMBER LISTING
[0078]
[0000]
20
Body, Front & Sides
21
Rear Body Panel
22
Bottom Body Panel
23
Cover Hinge
24
Top Access Cover
25
Cover Handle
26
Cover Latch
27
Wall Mount Bracket, Device
28
Wall mount bracket, wall
29
Leveling feet
30
Rubber seal
31
Hopper
32
Delivery Mechanism housing top ring
33
Delivery Mechanism housing top
34
Delivery Mechanism housing curved
35
Delivery Mechanism housing opp. motor
36
Delivery Mechanism housing motor side
37
Delivery Mechanism bolts
38
Delivery Mechanism bolts spacer
39
Rotor
40
Rotor shaft
41
Bushing
42
Thrust bushing
43
Bushing Housing
44
Thrust bushing housing
45
Rotor shaft coupling
46
Rotor shaft key
47
Delivery Motor shaft coupling
48
Delivery Motor mount plate
49
Delivery Motor mount plate bolts
50
Delivery System Motor
51
Delivery System Chute
52
Scale basket
53
Scale motor mount plate
54
Scale release gate
55
Scale release gate physical stop
56
Scale release gate limit switches, activated when open
57
Scale Release Gate Motor
58
Scale pivot shaft
59
Scale pillow bearings
60
Scale optical encoder
61
Scale counter balance
62
Scale counter balance weights
63
Scale counter balance spring
64
Food Exit Chute
65
Chute shield
66
Feed bowl
67
Water bowl
68
Water tank
69
Float valve
70
Water tank bottom connection
71
Water supply connection
72
Water drain connection
73
Overflow connection
74
Water pump
75
LCD display
76
Keypad
77
Electrical Connection and Plug
78
Electrical connection gland
79
Transformer
80
Circuit board with microprocessor controller
81
Open cover switch
82
Solenoid valve
83
Internal frame
84
Scale motor to release gate coupling
85
Scale release gate limit switches, activated when closed
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A device catering for the dietary needs of animals. Feed is stored in a hopper and distributed at intervals to the animal's feeding receptacle via an internal dispensing mechanism using a flexible rotor sealing against the walls of a housing to both meter the feed and seal against contamination. The quantities and delivery times may be set by the user. An optional weighting system can be provided to increase accuracy of delivered feed amounts. Optionally, the device may include a water delivery system. Water is provided by a plumbed domestic connection and is available to the animal at all times, except during the automatic change cycle. A pump is utilized to change the water several times a day, in an attempt to remove any contaminants that may affect the water quality that is required to be dispensed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2009/061745, filed Sep. 10, 2009 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 08019364.2 EP filed Nov. 5, 2002. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a process for removing a coating from surfaces of components.
BACKGROUND OF INVENTION
[0003] The cleaning of and removal of a coating from the inner, but also the outer surface of gas turbine blades or vanes during refurbishment is an important requirement for subsequent repair processes, for example during soldering or welding. If too many oxidic residues or residual layers of the original inner or outer alitization which contain a relatively large quantity of aluminum remain on the surface of the component, the subsequent crack cleaning process (HF cleaning or FIC) cannot penetrate into the crack tips, since too much process gas is consumed for converting the surface oxides and residual layers which have remained. This is problematic particularly on the inner surface of the component, since said surface is largely inaccessible for conventional mechanical blasting processes and therefore the oxide layer produced during operation on the inner alitization cannot be damaged mechanically or removed. According to an existing assumption, this in turn restricts the access of chemical etchants to diffusion zones which contain a relatively large quantity of aluminum.
[0004] The process applied, which consists of a combination of a molten salt bath and acid bath cleaning, chemically cleans the inner surface initially by basic digestion of the oxides in strong alkaline solutions and then by acidic digestion of the diffusion zone of the inner alitization which contains a large quantity of aluminum only partially or inadequately. In total, three different wet-chemical processes with hot, highly concentrated salt solutions, bases and acids with different flushing and drying procedures are required.
SUMMARY OF INVENTION
[0005] It is therefore an object of the invention to simplify the problem mentioned above in an economic and technical respect.
[0006] The object is achieved by a process as claimed in the claims, in which process only hydrochloric acid is used.
[0007] The dependent claims list further advantageous measures which can be combined with one another, as desired, in order to achieve further advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a list of superalloys, and
[0009] FIG. 2 shows a turbine blade or vane.
[0010] The invention is explained in more detail with reference to examples.
DETAILED DESCRIPTION OF INVENTION
[0011] The interior of turbine blades or vanes 120 , 130 ( FIG. 2 ) consisting of nickel- or cobalt-based superalloys ( FIG. 1 ) is often also alitized so that said blades or vanes are protected in their interior, since the interior of the turbine blade or vane 120 , 130 is cooled by means of hot steam. The alitization represents for the most part or completely a diffusion layer.
[0012] During the refurbishment, it is expedient to remove the alitization, so that a new alitization can be carried out or so as to simply remove damaged layer regions.
[0013] According to the invention, the interior or in general terms the surface is cleaned using only hydrochloric acid and not using an acid mixture, or else not with the use of or pretreatment by means of fused salts (KOH, NaOH). Similarly, no FIC cleaning is carried out to remove the alitization.
[0014] The concentration of the hydrochloric acid (HCl) is preferably 15% to 30% and very preferably 20% to 25%. The proportion of HCl is preferably calculated in % by weight.
[0015] The acid treatment is preferably carried out up to eight times, in particular at least twice. The acid treatment is preferably carried out twice to 6 times and very preferably 3 to 4 times.
[0016] This depends on the alitization and the service life of the component 120 , 130 .
[0017] The treatment duration in the acid bath is in particular at least 2 hours, in particular 2 to 2.5 hours.
[0018] The sole etching in hydrochloric acid means that two process steps which involve a large amount of energy and chemicals are eliminated from the existing process. The inner cleaning can even advantageously take place at the same time as the outer cleaning (removal of an MCrAlY coating), and this provides additional synergies.
[0019] In particular, a mechanical blasting process can precede the chemical etching process or can be used between the two acid treatments of the chemical etching.
[0020] This preferably involves inner vacuum blasting (abrasive agent is sucked by reduced air pressure through the cavities in the component) or an abrasive, low-viscosity fluid flowing through the component (for example water jet cleaning with abrasive particles). Similarly, watering preferably takes place between the acid treatments.
[0021] During operation, the inner alitization has already suffered a sufficient amount of damage (e.g. cracks, spalling, etc.). This damage represents points at which the acid can attack. At such damaged locations, the acid can also get behind still intact points of the inner alitization so that the latter are detached from the substrate (nickel superalloy) and drop off.
[0022] The temperature of the hydrochloric acid bath is preferably at least room temperature, very preferably 60° C. to 70° C.
[0023] Here, “acid treatment” is understood to mean the residence time of the component in the acid bath until it is removed and, for example, watered, internally blasted, inspected (degree of coating removal) etc. or immersed in a new, fresh acid bath.
[0024] FIG. 2 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0025] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0026] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 and a main blade or vane part 406 and a blade or vane tip 415 .
[0027] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0028] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0029] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0030] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0031] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0032] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949.
[0033] The blade or vane 120 , 130 may in this case be produced by a casting process, by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0034] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0035] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0036] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0037] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures (directionally solidified structures).
[0038] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1.
[0039] The blades or vanes 120 , 130 may likewise have coatings protecting against corrosion or oxidation e.g. (MCrAlX; M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element, or hafnium (Hf)). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0040] The density is preferably 95% of the theoretical density.
[0041] A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).
[0042] The layer preferably has a composition Co-30Ni-28Cr-8Al-0.6Y-0.7Si or Co-28Ni-24Cr-10Al-0.6Y. In addition to these cobalt-based protective coatings, it is also preferable to use nickel-based protective layers, such as Ni-10Cr-12Al-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1.5Re.
[0043] It is also possible for a thermal barrier coating, which is preferably the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, to be present on the MCrAlX.
[0044] The thermal barrier coating covers the entire MCrAlX layer. Columnar grains are produced in the thermal barrier coating by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0045] Other coating processes are possible, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks. The thermal barrier coating is therefore preferably more porous than the MCrAlX layer.
[0046] Refurbishment means that after they have been used, protective layers may have to be removed from components 120 , 130 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed. If appropriate, cracks in the component 120 , 130 are also repaired. This is followed by recoating of the component 120 , 130 , after which the component 120 , 130 can be reused.
[0047] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines).
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The removal of a coating from components after they have been used is often achieved using various acid baths and salt melts. A coating removal process that includes only using hydrochloric acid is provided. The duration of the process in which the coating is treated with the hydrochloric acids has a duration of between 2 and 2.5 hours. The process includes treated the coating with the hydrochloric acid at least twice.
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This application is a division of application Ser. No. 08/575,495 filed Dec. 20, 1995, which application is now U.S. Pat. No. 5,704,960.
BACKGROUND OF THE INVENTION
The present invention relates to rare earth doped fiber having a large number of spins and which is suitable for use in amplified fiber optic systems.
Polarization hole-burning (PHB) and polarization-dependent gain (PDG) are two anisotropic gain effects that limit erbium-doped fiber-amplifier (EDFA) transmission systems of the prior art. While this is a relatively small effect in a single amplifier, it seriously reduces the signal-to-noise ratio in long haul, e.g., transoceanic systems because of the large number of cascaded EDFAs.
Polarization-hole burning occurs when a saturating light signal robs gain from any weaker light signal in the fiber with the same polarization as the stronger signal. As a result, the polarization orthogonal to saturating light signal experiences an enhanced (anisotropic) gain, ΔG. In fiber-amplifier transmission systems, randomly polarized amplified spontaneous emission (ASE) noise is present along with the gain saturating data signal. The ASE component orthogonal to the signal polarization experiences higher gain at each amplifier and grows faster than predicted. Since amplified systems usually operate in gain compression with constant amplifier output power, the fast growing ASE noise robs power from the data signal and the signal-to-noise ratio drops.
Polarization-dependent gain, on the other hand, is an anisotropic gain caused by the pump lightwave polarization. Erbium ions within the random distribution of orientations that are aligned along the same axis as the pump polarization are preferentially excited. Light with the same polarization de-exites these ions to experience excess gain in comparison to other polarizations. This also degrades the system performance.
Polarization properties of the incident light and within the amplifier gain can have a dramatic effect on PHB and PDG. The PHB effect was recently illustrated in highly birefringent erbium-doped fiber as reported by V. J. Mazurczyk and C. D. Poole, "The Effect Of Birefringence On Polarization Hole Burning In Erbium Dope Fiber Amplifiers," Proc. Optical Amplifier Conference, ThB3-1, 77-79, 1994. As shown by the authors, FIG. 1 illustrates the difference in gain for a probe signal polarization parallel vs perpendicular to a saturating signal as a function of the signal launch angle in a highly birefringent fiber. According to the bulk amplifier model, a maximum in gain anisotropy is expected for linear polarization and no anisotropy for circular polarization. Therefore, when the signal is launched along one of the birefringent axes (θ=0° or 90°) it stays linearly polarized and the greatest gain difference occurs. At 45°, the signal evolves through the greatest range of polarization states and averaging of the local differential gain throughout the amplifier reduces the overall gain difference. Randomizing the birefringence (as shown in FIG. 2 by winding the highly birefringent fiber of FIG. 1 on a 1" diameter drum) randomizes the polarization evolution and reduces ΔG. It is well known that conventional EDFAs have low birefringence (beat length of a few meters) so that random birefringence lowers the launch polarization dependence on gain even more (FIGS. 3 and 4). In fact, P. F. Wysocki, "Polarization hole-burning in erbium-doped fiber amplifiers with birefringence," Optical Amplifier Conference, 80-82, ThB4-1, 1994, has quantified this dependence on degree of linearity (DOL) by the following equation: ##EQU1## In the above equation, DOP is the degree of polarization, DOL is the degree of linearity, L is the fiber length, and α is 1 or 2 for the partially or entire polarized portion of the signal respectively. The degree of linear polarization, DOL will average to 2/3 when integrated over the entire Poincare sphere. This is because two polarized waves will exhibit linear through circular states of polarization as the faster polarization passes by the slower polarization. This will occur many times in a typical erbium doped fiber, as discussed in the Wysocki Article.
The degree of polarization, DOP is defined using the "principal states of polarization." It is this parameter that is the subject of the present invention. The principal states refer to the polarization eigenfunctions (i.e., eigenpolarization) and in a straight elliptical fiber these states have eigen-polarizations along with the major and minor axis. These eigen-polarizations remain constant throughout the fiber, whereas the signal states of polarization traverse the Poincare sphere. In a twisted-elliptical fiber, for example, the eigen-polarizations are functions of the major and minor axis as well as the twist rate. One approach to reducing the DOP is by scrambling the polarization at the transmitter. This, however, has the disadvantage of requiring a costly active component to scramble the polarization.
The present invention is directed to minimizing the polarization dependent gain, ΔG, in equation 1, by minizing the DOP. The DOP is defined by N. Gisin, in "The Statistics of Polarization Dependent Losses', Symposium on Fiber Optics Measurements', NIST, p 193-196, 1994, for example, as:
DOP=|M| (2)
where |M| is related to the stokes parameters, S 1 , S 2 , and S 3 : M=(S 1 2 +S 2 2 +S 3 2 )1/2/S 0 and S 0 is the total power. The vector M is related to the mixture of the two orthogonal polarization state because "unpolarized light can be considered as an equal mixture of orthogonal polarization states." The DOP can be then forced to zero by ensuring that there is equal power in both orthogonal polarizations.
SUMMARY OF THE INVENTION
The present invention is directed toward eliminating polarization hole burning and polarization dependent gain in amplified fiber optic systems. This is accomplished by minimizing the DOP by creating a large number of polarization mode coupling sites within the fiber that cause equal population of the two orthogonal states of polarizations. The creation of a large number of polarization mode coupling sites within the fiber ensures a high probability that equal populations of the polarization eigenstates will occur in a statistical sense as the light propagates down the doped fiber. Increased polarization mode coupling of the input signal will reduce polarization hole burning; increased mode coupling of the pump laser light will reduce polarization dependent gain.
In the present invention, spinning or twisting a single mode rare earth doped fiber through a range of rotation rates as shown in FIGS. 7-10, and alternating the direction of rotation introduces the necessary coupling between orthogonal polarization modes. This can be achieved in the fiber drawing process by spinning in a prescribed way so as to induce several if not many polarization mode coupling sites. The rotation rate is determined by the fiber birefringence, and the number of reversal rates is determined by the desired number of polarization mode coupling sites. Since the local birefringence within a segment of the fiber is unknown and can vary, a range of rates and reversal lengths rather than a fixed constant value is desired. Spinning of transmission fiber for reducing polarization mode dispersion is well known, while in the present invention, spinning of the amplifier fiber reduces two unrelated polarization effects.
It is well known that spinning or twisting fiber in a continuous or clockwise and counterclockwise direction can be used to reduce polarization mode dispersion, see for example Ulrich and Simon (Polarization Optics of Twisted Single Mode Fibers, Applied Optics Vol 18, No. 13, Jul. 1, 1979) and also Payne et al. (PCT Application No. 83/00232) and also Hart et al. (U.S. Pat. Nos. 5,298,047 and 5,418,881). Twisting in one direction reduces the time delay differences between the two polarization modes as the light propagates down the fiber as explained in Payne. Polarization mode coupling which results from twisting or spinning in both directions can be used to compensate the time delay differences. This is explained in Ulrich and Simon on p2250. The distance over which this mode exchange takes place can be rather large, for example, tens or even hundreds of meters. In fact, Ulrich and Simon propose that it can be done once in the middle of the transmission span. Little has been published as to how often this exchange should occur, but it should occur before random coupling effects cause mode mixing which eliminate the possibility of proper mode mixing for compensation.
With respect to PHB and PDG, the prior art is silent with respect to how spinning or twisting will minimize or even address these effects. The formulas developed in Hart et al. and in Payne et al. for PMD are not applicable for PHB and PDG. For these two phenomena, proposed mode coupling in the present invention is used to prevent the worse case situation where incident light in an EDFA fiber remains in that fiber in one polarization eigenstate as it propagates down the entire length of the fiber. By causing many polarization mode coupling sites in the fiber, it is ensured statistically that this worse case situation does not happen. In the present invention, these mode coupling sites occur at intervals of 1/2 meter or less. The spin rates are then dictated by the teachings developed by Ulrich and Simon.
Additionally, this polarization mode coupling effect may be further enhanced by fabricating a preform with a small but finite amount of birefringence through either form ellipticity or stress. In order that the birefringent length be known and therefore be better able to specify the spin and reversal lengths, we can fabricate the fiber with a finite birefringence. This birefringence can be added by forming the fiber with a small ellipticity or stress. Formulas for how ellipticity and stress effect birefringence are developed by Rashleigh (Origins and Control of Polarization Effects in Single Mode Fibers, Journal of Light Wave Technology, Vol. 1, No. 2, June 1983). Finite birefringence has at least two advantages. First, the finite-birefringence, doped fiber would be insensitive to additional twist birefringence and unintentional mode coupling caused by its tight coiling in the amplifier package. Second, a finite birefringence would dominate unintentional birefringence introduced during the fiber fabrication process. Hence, the required spin rate and reverse length would be clearly defined.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 illustrate EDFA's of the prior art illustrating polarization hole burning or various birefringence and deployment.
FIG. 5 is a schematic illustration of a fiber drawing apparatus suitable for use in carrying out the present invention.
FIG. 6 is a perspective view of a segment of an optical fiber made by the present invention.
FIGS. 7-10 illustrate various spin rates as a function of fiber length for making optical fiber of the present invention.
FIG. 11 is a schematic illustration of one embodiment of using optical fiber of the present invention in a rare earth doped fiber amplifier.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is illustrated with reference to the drawings where FIG. 5 is a schematic representation of the fiber drawing apparatus 10 suitable for use in carrying out the present invention. As shown in FIG. 5, a preform 12 is mounted vertically in the furnace 14 and heated until molten glass can be pulled from the preform in the form of a fine fiber 16. The fiber diameter is measured at a monitoring station 18 and the fiber then coated at a coater station 20 with a protective plastic layer (not shown) as it is continuously pulled from the preform. In the present invention, the fiber then passes through a series of rollers 22, 24 and 26 at least one of which (22) is rotated to cause a torque to be applied to the fiber at regular intervals alternately in a clockwise and counterclockwise direction as more fully described herein. After passing roller 26, the fiber is wound around storage drum 28.
The fiber drawing portion of the schematic described in FIG. 5 represents apparatus well known to those skilled in the art. The resultant fiber formed from the process illustrated in FIG. 5 is depicted in FIG. 6 which is a perspective view of a segment of a length of optical fiber made by the present invention. This fiber has alternating lengths of spin or twist which have been formed by applying torque alternately in the clockwise and then in the counterclockwise direction or visa versa, as described above. The spin or twist of this fiber is uniform in each alternating length. The reversal length is denoted as L and is the length, in meters, between spins in the opposite direction. The angle, θ in degrees or radians, denotes the total rotation the fiber undergoes in one direction before the sign of the rotation changes and the fiber spins or twists in the opposite direction. For the fiber depicted in FIG. 6, with constant spin which alternates in the clockwise and counterclockwise directions, the spin rate in twists/meter is easily defined as θ/(360°×L) if the angle is in degrees or θ/(2 π×L) if the angle is in radian. More generally, the fiber can have nonuniform twist throughout its length. The parameters, θ and L, have the same definition but the spin rate becomes locally defined and can change value within a very small distance. The angle θ may vary from about 60° to 360° where 360° is a complete rotation. In some cases, 1 to 5 complete rotations may be employed. The local spin rate is related to the ratio of the instantaneous angle of rotation change to an infinitesimal length of fiber. In calculus notation, the local spin rate is 1/360 or 1/pi multiplied by dθ/dL.
U.S. Pat. Nos. 5,298,047 and 5,418,881 teach prior art techniques and apparatus which may be used in the present invention whereby torque can be applied by guide roller means causing the guide rollers to oscillate about an axis which is substantially normal to the fiber drawing direction and normal to the roller rotation direction. These references are incorporated herein by reference. In addition, published PCT application WO 83/00232 entitled "Optical Fibers And Their Manufacture," and M. J. Marrone et al. (Internal Rotation of the Birefringence Axes In Polarization Holding Fibers, 1987 Optical Society of America) also teach prior art techniques and apparatus for providing twists at regular intervals in an optical fiber. The torque to provide the twist may be accomplished either by rotating the preform or by the manipulation of guide rollers as taught by the prior art. U.S. Pat. Nos. 4,509,968 and 4,308,045 also provides a device and method for impressing torsional stresses on a fiber which may be used in providing the spin or twist in fiber of the present invention and is incorporated herein by reference.
FIGS. 7-10 illustrate various spin rates as a function of the fiber length for use in the manufacture of optical fibers of the present invention. The most basic spin rate change along the fiber is illustrated in FIG. 10. Any spin function can be written as a linear superposition of constant and sinusoidal functions as illustrated in FIGS. 7-9. As previously described and illustrated in FIG. 6, the desired reversal length, L, is dependent on the desired number of the mode coupling sites, and the spin rate is dependent upon the fiber birefringence. The reversal length defines the period of the sinusoidal function in FIG. 10. However, the fiber must support mode-mixing sites at both the signal wavelength and the pump laser wavelength. Because the fiber birefringence is dependent on wavelength, the spin profile needs to be a superposition of two sinusoids, one to create mode-mixing at the signal wavelength and one to create mode-mixing at the pump laser wavelength. FIGS. 7-9 are spin functions created by mixing a fundamental sinusoid with different higher order harmonics. Therefore, in order to account for the variations in birefringence of the optical fiber, various other spin rates may be considered and used as described above. As the spin amplitude and frequency change, phase matched or nearly matched mode coupling can occur in a broad band of fiber birefringence. As previously stated above, the spin rate along the fiber length is largely dependent upon local birefringence. Rare earth doped single mode fibers of the present invention may be made using any one of the above spin rates or spin rates analogous thereto may be employed depending upon the birefringence of the fiber being processed.
FIG. 11 is a schematic illustration of a rare earth doped fiber amplifier 30 which utilizes optical fiber produced by the present invention. In FIG. 11, a weak optical input signal 32 enters from the left passing through a wavelength division multiplexing coupler 34 which combines it with light from an external pump source 38. The pump and the signal light then enters one end of an erbium doped fiber 36, typically 20 to 30 meters long. The light from the pump excites the dopant atoms raising them to a higher energy level. Light at the signal wavelength stimulates the excited atoms to deexcite down to their ground state and emit the excess light energy at the signal wavelength, the amplified signal 40 is then directed to the output fiber.
The present invention is applicable to any single mode rare earth doped fiber, but erbium-doped fibers are used in the particular embodiments described herein. Typically these fibers have an outer diameter of about 125 microns and an inner core having a diameter of about 5 to 6 microns.
The fiber core and cladding are preferably made of high purity fused silica. In general, several twists per meter, as dictated by the birefringence of the fiber, are impressed upon the fiber with an alternative torque being applied at intervals of about 1/2 meter or less. Typically, about 1 to 4 twists per meter are satisfactory.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawings, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
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A single mode optical fiber suitable for use in an amplified fiber optic system which includes an inner glass core doped with a rare earth element and an outer transparent glass cladding. The fiber exhibits a plurality of mode coupling sites formed at regular intervals along the length of the fiber which provides for a reduced DOP. The sites are formed by a twist at regular intervals along the fiber length by applying a torque to the fiber. The method of forming the fiber is also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a jacquard mechanism for controlling a shedding motion of warps set on a loom, particularly to an improvement of an electronic jacquard mechanism in which a solenoid of a needle selection device is directly operable by a command signal from a computer.
2. Description of the Related Art
In a traditional jacquard mechanism well-known in the art, specific dropper needles are selected at every pick of a weft in accordance with a position of a perforation on a pattern card.
In this jacequard mechanism, a large number of pattern cards, usually tens of thousands, are necessary for completing a pattern. These cards are connected one by one to form an endless belt and set in the mechanism so that they successively confront a selection device synchronously with a rotation of a main shaft. A considerable amount of space is needed for this. Also, the preparation of the pattern cards requires considerable time and labor. Further, setting and amending the cards are very troublesome. This problem is particularly, bothersome when just making samples of various weave patterns. It requires several months from the beginning of preparation of the pattern cards to the completion of the weaving on the loom.
Recently, to solve the problem, a so-called "electronic" jacquard mechanism utilizing a computer has been developed. In this mechanism, a magnetic tape or disc memories the pattern information and thus does away with the lengthy belt of pattern cards. Most such mechanisms further omit the dropper needles themselves to simplify the device. Instead, horizontal needles arranged in a final stage of the selection device are controlled by a solenoids.
This mechanism has, however, a serious drawback. Since the horizontal needles are urged to their waiting position by springs, an attactive force of at least 300 g.wt. is necessary to displace it or hold them in a selection position. This means the solnoids must be of a large capacity, therefore, large size. On the other hand, since a large number of horizontal needle, e.g., 1,000 to 2,000, are arranged in the jacquard mechanism for controlling the warps, the pitch between adjacent needles must be as small as possible to keep the overall installation small. Since the solenoids are large in size, however, they cannot be arranged at a small pitch corresponding to that of the horizontal needles. To solve this problem, the solenoids are disposed apart from the horizontal needles. The solenoids and needles are connected by flexible components such as steel wires or synthetic fiber cords. Due to repeated stress, however, the flexible components tend to stretch with the time, resulting in indefinite displacement of the horizontal needles. In the worst case, the flexible components break due to material fatigue.
In view of this drawback, the present inventors previously proposed a system in Japanese Unexamined Utility Model Publication (Kokai) Nos. 56-107878, 57-18680, 57-34587, 57-34973, and 58-87884 in which periodically reciprocating dropper needles are selectively attracted by corresponding solenoids. Because a much smaller force is required for operating dropper needles compared to horizontal needles in conventional mechanisms, solenoids of a smaller capacity and, therefore, a smaller size are sufficient and the compactness of the jacquard mechanism can be maintained without problem. The present invention is an improvement of this system.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a solenoid dropper-needle system offering stable control under high processing speeds and further compactness.
The above object of the present invention is achievable by a jacquard mechanism for controlling a shedding motion of warps set on a loom, including a plurality of axially displaceable dropper needles, each associated with a group of warps, and a plurality of solenoids, each corresponding to one of the dropper needles. A computer, storing the pattern information, issues commands to selectively energize the solenoids to hold the corresponding dropper needles. The mechanism of the present invention specifically includes a printed board on which a circuit for transmission of command signals from the computer to the solenoids is printed; solenoids including stationary cores, accommodated in housings secured, along with coils, directly on the printed board and disposed at predetermined positions along extensions of axes of the dropper needles, and movable cores, fixed to ends of the dropper needles closer to the stationary cores; means for periodically reciprocating all of the dropper needles along each longitudinal axis thereof from a first position where the movable and stationary cores are apart from each other at a predetermined distance to a second position where the movable and stationary cores substantially come into contact with each other; a guide plate provided with a plurality of holes for stably guiding the movable cores during thre reciprocation of the dropper needles; and means for urging the dropper needles toward the first position.
Preferably, the reciprocating means for the dropper needles includes a lifter plate for supporting the dropper needles at the ends opposite to those connected to the stationary cores, and cam means for moving the lifter plate.
More preferably, the lifter plate is covered with a resilient sheet on the surface receiving the dropper needles for compensating for variance of the actual distance between the first and second positions of the dropper needles.
Alternately, the lifter plate is provided with a plurality of cushion means on a surface receiving the dropper needles, the position of each means corresponding to that of the dropper needles.
Further, the dropper needles are preferably urged by compression springs toward the lifter plate for facilitating the return to the first position.
The solenoids may be arranged with alternating polarities of coils in each row.
Further, the housings of the solenoids preferably include a shield made of a ferro magnetic material for preventing leakage of magnetic flux therefrom.
The housings may be provided with marks at free end surfaces for identifying positions of beginning ends of the coils wound therearound.
The solenoids to be utilized in the present invention need only have an attractive force of 10 g.wt. and can be arranged on the printed board with a pitch in a range of from 4 mm or 5 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention will be apparent from the following description with reference to the attached drawings illustrating the preferred embodiments of the present invention, in which:
FIG. 1 is a diagrammatical sectional side view of an embodiment according to the present invention;
FIGS. 2 and 3 are sectional side views of part of a lifter plate provided with resilient means for receiving a dropper needle;
FIG. 4 is a view similar to FIG. 1, illustrating another embodiment according to the present invention;
FIG. 5 is a side view of a solenoid suitable for the present invention;
FIG. 6 is a perspective view of a solenoid engaged with a tool utilized for detachment and attachment thereof on a printing board; and
FIG. 7 is a plan view of an arrangement of the solenoids on the printed board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In this specification, in principle, the term "solenoid" means an assembly including a housing, in which a stationary core is accommodated and around which a coil is wound to encircle the stationary core, and a movable core, operating as a plunger, which is displaceable in the axial direction by the magnetic force of the stationary core generated by a current flowing through the coil. Sometimes, the term also designates only the stationary part thereof without the movable core. The distinction between the two will be apparent from the related description and the drawings.
FIG. 1 illustrates the main part of the jacquard mechanism according to the present invention. The mechanism includes a plurality of vertically arranged dropper needles 1, though only one is illustrated in FIG. 1 to simplify the drawing. A hook-shaped lower end of the dropper needle 1 rests on a lifter plate 15 which is always downwardly urged by return springs 17 and is reciprocated through a definite distance in the vertical direction by means of a lifter cam 14 rotating sychronously with the rotation of a main shaft. Therefore, the dropper needle 1 can be moved from the lowest position (below, "first position") to the highest position (below, "second position"). The hooked end of the dropper needle 1 is loosely held in a slot provided in a hook plate 13 so as not to rotate about its own axis.
The dropper needle 1 has an eyelet in the midportion thereof through which a horizontal poker 2 is loosely inserted. The poker 2 is displaced in the vertical direction with the above reciprocation of the dropper needle 1, but is freely movable, separately from the latter, in the horizontal direction.
One end of the poker 2 is inserted into the interior of a pusher box 3 through an aperture 3a provided on a side wall of the pusher box 3. The aperture 3a has enough of a clearance relative to the poker 2 so that the poker 2 can move from the lower position, corresponding to the first position, to the upper position, corresponding to the second position, following the movement of the dropper needle 1.
The pusher box 3 has a plurality of pushing elements 4 therein, each corresponding to a poker 2. In FIG. 1, only one is illustrated for the sake of simplicity. The pushing element 4 is disposed so that, when the poker 2 is in the upper position, it does not confront the end of the poker 2 and, on the other hand, when the poker 2 is in the lower position, it confronts the poker 2.
Further, the pusher box 3 is periodically reciprocated synchronously with the rotation of the main shaft of the loom in the directions shown by a double-headed arrow A in FIG. 1. According to the above description, it will be understood that the poker 2 is operated by the pushing element 4 when disposed in the lower position. This pushing motion is transmitted to a corresponding horizontal needle 5 disposed adjacent to the poker 2. The actual shedding motion follows thereafter.
The needle selection device according to the present invention will now be described.
A movable core 6 of a solenoid 30 is coaxially fixed on the upper end of the dropper needle 1. The movable core 6 is movably inserted in a tubular housing 10 of the solenoid 30 through a guiding hole 7 provided on a guide plate 8 fixed to a machine frame. The housing 10 is held between a printed board 11 and a supporting plate 12 in a sandwich manner and disposed in alignment with the dropper needle 1. The housing 10 accommodates a stationary core 9 therein. A coil 20 is wound around the housing 10, and the ends of the coil 20 are directly connected to terminals on the printed board 11.
The printed board 11 is provided with a circuit on the surface thereof, which transmits a command signal from a computer (not shown) for energizing or deenergizing the solenoid 30. The computer stores therein pattern information for weaving by a loom and outputs the above signal to each solenoid synchronously with the rotation of the main shaft.
Starting from the first position shown in FIG. 1, the dropper needle 1 is lifted to the second position by means of the cam 14 and the lifter plate 15. Along with this, the movable core 6 fixed to the upper end of the dropper needle 1 enters deeper into the housing 10 and, at the utmost stage, abuts or reaches very near to the lower end of the stationary core 9. Just at this time or slightly prior to this time, the computer outputs the command signal to the selected solenoid 30, whereby the corresponding stationary core 9 is energized to attract the corresponding movable core 6. Then, the lifter plate 15 begins to move down.
According to the downward movement of the lifter plate 15, the dropper needle 1, which has not been attracted by the solenoid, is also brought back to the first position. A spring 16 ensures a stable return motion of the dropper needle 1 even under high speed operation. The spring 16 is sheathed around the movable core 6 and arranged beneath the guide plate 8 so as to urge the movable core 6 downward. Further, the spring 16 serves to suppress the bouncing motion of the dropper needle, which results in unreliable attraction of the cores.
The selected dropper needle 1 attracted by the solenoid 30 is left in the second position, in a suspended state. Therefore, the poker 2 corresponding to the suspended dropper needle 1 is also held in the upper position where the poker 2 does not confront the pushing element 4. Thereafter, the pusher box 3 moves to the right and the poker 2 remaining in the lower position is pushed to cause the horizontal needle to operate as stated before.
After the pusher box 3 returns to the left in its waiting position, the current supplied to the solenoid is shut and the solenoid is deenergized. The suspended dropper needle then immediately drops down on the lifter plate due to its own weight and the urging force of the spring 16. The same operation is repeated synchronously with the rotation of the main shaft.
In the embodiment, it is desired to make the distance between the first and second positions of all the dropper needles uniform even in the furthermost position so as to prevent undesired contact of cores. The distance should further be no more than 0.5 mm since attractive force generated from the stationary core is effective only within such a distance.
To avoid troublesome distance adjustment, as shown in FIG. 2, it is preferable to provide a resilient sheet 27 on the surface of the lifter plate 15 and to lift the dropper needle 1 until complete contact between the cores is attained. The resilient sheet will deform and absorb the shock caused by the collision of the cores. Instead of the resilient sheet 27, another cushion means 28, including a piston 28a urgingly held by a spring 28b, may be provided at the contact locations of the dropper needle 1 on the lifter plate 15 as illustrated in FIG. 3.
FIG. 4 shows another embodiment of the present invention, in which the cam 14 is disposed in the upper area and the printed board 11 is in the lower area. The operational principle of the dropper needle 1 is the same as that shown in FIG. 1.
According to the present invention, a suitable number of housings 10 of the solenoids 30 are secured between the printed board 11 and the supporting plate 12 in a sandwich manner. One end of each housing 10 is fixed on the printed board 11 along with the stationary core 9 and the coil 20. The other end thereof rests on the supporting plate 12. This assembly constitutes a unit which can be handled as a single, integrated component. A plurality of such components can be put together to form a larger device. This facilitates maintenance of the mechanism. If breakage occurs, the broken component can be replaced in a short time period.
Further, as stated before, the solenoids utilized for the present invention may be small in size since they need only control lighter weight size dropper needles. Therefore, they can be arranged directly on the printed board at a smaller pitch, which eliminates the need for connection wires and enables greater compactness of the overall installation. The solenoids can in practice be arranged at a pitch of less than 5 mm.
Moreover, a plurality of printed boards 11 may be piled up to form a large device.
FIG. 5 illustrates a strructure of an embodiment of the solenoid 30. At least two pins 18 for fixing the housing 10 on the board 11 are projected from a base end 19 of the housing 10 made of an insulation material, such as plastic. The pins 18 are connected to the beginning and terminal ends 20a, 20b of the coil 20, which is wound around a periphery of the midportion of the housing 10 in which the stationary core 9 is disposed. As shown in FIG. 6, on the side wall at the tip portion 21 of the housing 10 are provided a pair of holes 22 in a dramatically opposing manner. The holes 22 serve as holding apertures engageable with an outwardly projected end 24 of a special tool 25 utilized for pulling out the housing 10 from the printed board 11 or inserting it therein.
Further, the housing 10 preferably has a cover 26 therearound made of ferromagnetic material in order to shield the leakage of magnetic flux.
As illustrated in FIG. 7, the housings 10 are preferably set in a honeycomb manner for the densest arrangement. In such a case, each solenoid 30 preferably has a reverse polarity from those of the adjacent solenoids 30 in the same row for neutralizing the interaction therebetween. For this purpose, the beginning ends 20a of the coils are alternately connected to the plus or minus terminal on the printed board so that the current direction is reversed in adjacent coils. A notch 23 provided on the tip end of the housing 10 serves as a mark for identifying the position of the beginning end of the coil (FIGS. 5, 6, and 7).
As stated above, according to the present invention, numerous advantages can be obtained. Since the movable cores of the solenoids are integrally connected to the dropper needles, the motion of the dropper needles can be directly controlled by the solenoids.
Since the dropper needles are light in weight, e.g., less than 10 g, and, further, are brought into contact with the stationary cores of the solenoids by the lifter plate at the time when the solenoids are to operate, the solenoids can be smaller in size and consume less power than in conventional mechanisms.
The provision of springs around the movable cores enable stabler motion of the dropper needles, thereby enabling a loom speed of from 200 to 300 rpm, compared with the 130 rpm considered maximum in conventional mechanisms.
Finally, since the solenoids are directly secured on the printed board, no wires for electric connection is needed.
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An electronic jacquard mechanism for controlling shedding motion of warps by selectively holding dropper needles by means of solenoids in accordance with command signals generated from a computer. Movable cores of the solenoids are directly fixed on one end of the dropper needles. Housings of the solenoids, including stationary cores and coils, are secured directly on a printed board associated with the computer. The solenoids can be densely arranged on the printed board corresponding to the arrangement of the dropper needles, allowing greater compactness of the mechanism.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 62/131,420 titled “A ROBUST, LOW NOISE CURRENT-BASED APPROACH FOR TRS AND TRRS AUDIO PLUG TYPE DETECTION” and filed on Mar. 11, 2015, which is incorporated by reference herein.
TECHNICAL FIELD
[0002] This specification is directed, in general, to electronics, and, more specifically, to systems and methods for audio plug type detection.
BACKGROUND
[0003] In recent years, consumer electronic devices such as cell phones, portable media players, tablets, laptops, desktops, televisions, navigation systems, etc. have become ubiquitous. These devices often include an audio jack through which they receive and/or provide audio signals. Generally speaking, an audio jack is configured to receive an audio plug that is connected through electrical wires or cables to a stereo, receiver, speakers, headphones, etc.
[0004] Audio plugs can have any number of ring-shaped contacts, terminals, or poles along their lengths. A common type of audio plug is the TRS type, with “Tip,” “Ring,” and “Sleeve” terminals, in that order. Traditional TRS-type plugs carry the left channel (tip), right channel (ring), and ground (sleeve).
[0005] Another common type of audio plug is the TRRS type, with “Tip,” “first Ring,” “second Ring,” and “Sleeve” terminals, which may have different configurations: standard or Open Mobile Terminal Platform (OMTP). Contacts for a standard plug include the left channel (tip), right channel (first ring), ground (second ring), and microphone (sleeve). In an OMTP plug, the tip and first ring terminals also carry the left and right channels, respectively, but the second ring is a microphone contact and the sleeve terminal has the ground contact—i.e., the last two terminals are reversed relative to the standard plug.
[0006] Because a user may connect any type of audio plug to the same jack, detection circuitry has been developed to determine which type of audio plug is inserted.
[0007] Conventional plug detection is achieved by grounding the tip terminal, injecting a small electrical current first onto the second ring terminal (first detection), and then onto the sleeve terminal (second detection). A three-bit Analog-to-Digital (ADC) circuit measures the voltage on the second ring and sleeve terminals to convert the detected impedance to a digital value. If the impedance of the second ring is equal to the impedance of the sleeve terminal, the plug type is determined to be a 3-pole plug. Otherwise, if the impedance of the second ring is smaller than the sleeve impedance, the plug type is determined to be a 4-pole standard plug, and if the impedance of the second ring is greater than the sleeve impedance, the plug type is a 4-pole OMTP plug.
[0008] The inventors hereof have identified a number of problems with the aforementioned technique. For example, the dynamic range of the ADC needs to be wide enough to account for worst case headset resistance and worst case microphone resistance. Also, the Least-Significant-Bit (LSB) size needs to be small enough to account for minimum microphone resistance. For example, a 3-pole headset may be incorrectly detected as 4-pole if headset's resistance falls right at bin boundary of the ADC.
SUMMARY
[0009] Systems and methods for audio plug type detection are described. In an illustrative, non-limiting embodiment, a method may include receiving an audio plug at an audio jack; grounding a sleeve terminal of the audio jack; applying an electrical current to a second ring terminal of the audio jack; and measuring a voltage between the second ring terminal and the sleeve terminal. In many situations, the audio jack is of an unknown type. For example, the electrical current may be of the order of 1 μA.
[0010] The method may also include, in response to the magnitude of the voltage being approximately zero, determining that the audio plug is a 3-pole type. Additionally or alternatively, the method may include, in response to a magnitude of the voltage being greater than zero, determining that the audio plug is a 4-pole type. For example, the voltage may be of the order of 500 mV.
[0011] The method may further comprise grounding a tip terminal of the audio plug; applying another electrical current to the sleeve terminal and to the second ring terminal of the audio plug; measuring a first voltage between the sleeve terminal and the tip terminal; and measuring a second voltage between the second ring terminal and the tip terminal.
[0012] In some cases, applying the other electrical current may include concurrently applying the other current to the sleeve terminal and to the second ring terminal. The other electrical current may be of the order of 1 μA, and a difference between the first and second voltages may be of the order of 200 mV.
[0013] In response to a magnitude of the first voltage being greater than a magnitude of the second voltage, the method may include determining that the audio plug is a standard 4-pole audio plug. In response to a magnitude of the first voltage being smaller than a magnitude of the second voltage, the method may include determining that the audio plug is an Open Mobile Terminal Platform (OMTP) 4-pole audio plug.
[0014] In another illustrative, non-limiting embodiment an electronic circuit may include a controller; and a memory coupled to the controller, the memory having program instructions stored thereon that, upon execution by the controller, cause the controller to: ground a sleeve terminal of an audio jack; apply an electrical current to a second ring terminal of the audio jack; and measure a voltage between the second ring terminal and the sleeve terminal.
[0015] The program instructions, upon execution, may further cause the controller to, in response to the magnitude of the voltage being approximately zero, determine that the audio plug is a 3-pole type. Additionally or alternatively, the program instructions, upon execution, may further cause the controller to, in response to a magnitude of the voltage being greater than zero, determine that the audio plug is a 4-pole type. Additionally or alternatively, the program instructions, upon execution, may further cause the controller to ground a tip terminal of the audio plug; concurrently apply another electrical current to the sleeve terminal and to the second ring terminal of the audio plug; measure a first voltage between the sleeve terminal and the tip terminal; and measure a second voltage between the second ring terminal and the tip terminal.
[0016] The program instructions, upon execution, may further cause the controller to, in response to a magnitude of the first voltage being greater than a magnitude of the second voltage, determine that the audio plug is a standard 4-pole audio plug. Additionally or alternatively, the program instructions, upon execution, may further cause the controller to, in response to a magnitude of the first voltage being smaller than a magnitude of the second voltage, determine that the audio plug is an OMTP 4-pole audio plug.
[0017] In yet another illustrative, non-limiting embodiment, an audio device may include an audio jack configured to receive an audio plug of an unknown type; and an electronic circuit coupled to the audio jack, the electronic circuit configured to: ground a sleeve terminal of the audio jack; apply an electrical current to a second ring terminal of the audio jack; measure a voltage between the second ring terminal and the sleeve terminal; and at least one of: in response to the magnitude of the voltage being approximately zero, determine that the audio plug is a 3-pole type, or in response to a magnitude of the voltage being greater than zero, determine that the audio plug is a 4-pole type.
[0018] The electronic circuit may be further configured to: ground a tip terminal of the audio plug; concurrently apply another electrical current to the sleeve terminal and to the second ring terminal of the audio plug; measure a first voltage between the sleeve terminal and the tip terminal; measure a second voltage between the second ring terminal and the tip terminal; and at least one of: in response to a magnitude of the first voltage being greater than a magnitude of the second voltage, determine that the audio plug is a standard 4-pole audio plug, or in response to a magnitude of the first voltage being smaller than a magnitude of the second voltage, determine that the audio plug is an OMTP 4-pole audio plug.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Having thus described the invention(s) in general terms, reference will now be made to the accompanying drawings, wherein:
[0020] FIG. 1 is a diagram of an example of an audio system according to some embodiments.
[0021] FIG. 2 is a block diagram of an examples of an for audio plug type detection circuit according to some embodiments.
[0022] FIG. 3 are diagrams of examples of various audio plug types detectable according to some embodiments.
[0023] FIG. 4 is a flowchart of an example of a method for audio plug type detection according to some embodiments.
[0024] FIG. 5 are diagrams of examples of a first detection stage according to some embodiments.
[0025] FIG. 6 are diagrams of examples of a second detection stage according to some embodiments.
DETAILED DESCRIPTION
[0026] The invention(s) now will be described more fully hereinafter with reference to the accompanying drawings. The invention(s) 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(s) to a person of ordinary skill in the art. A person of ordinary skill in the art may be able to use the various embodiments of the invention(s).
[0027] In many implementations, some of the systems and methods disclosed herein may be incorporated into a wide range of audio-enabled electronic devices including, for example, computer systems, portable audio systems, consumer electronics, automotive systems, and professional audio equipment.
[0028] Examples of consumer electronics include television sets, A/V receivers, home theater or sound systems, set-top boxes, docking stations, soundbars, sound projectors, etc. Examples of portable audio systems include tablets, smartphones, media players, camcorders, etc. Examples of automotive audio systems include audio distribution, infotainment, in-seat entertainment, etc. Examples of professional audio systems include recording, live and installation sound, musical instruments, etc. It should be noted, however, that these examples are not limiting, but only demonstrative of the various types of systems which may incorporate the present embodiments, and that additional applications may be possible. More generally, these systems and methods may be incorporated into any device or system having one or more electronic audio parts or components.
[0029] Turning to FIG. 1 , a diagram of an environment where certain systems and methods described herein may be implemented is depicted. As illustrated, one or more devices or systems such as, for example, automobile 102 , loudspeakers 103 , A/V receiver 104 , and/or audio recording equipment 105 (or any other audio-enabled device or system) may include printed circuit board (PCB) 101 having electronic circuit 100 mounted thereon. In some embodiments, electronic circuit 100 may include one or more analog, digital, and/or mixed signal integrated circuits (ICs) configured to perform loudspeaker protection against excessive excursion, as discussed in more detail below.
[0030] In one embodiment, electronic circuit 100 may include an electronic component package configured to be mounted onto PCB 101 using a suitable packaging technology such as Ball Grid Array (BGA) packaging, pin mount packaging, or the like. In some applications, PCB 101 may be mechanically mounted within or fastened onto the electronic device. In other implementations, however, PCB 101 may take a variety of forms and/or may include a plurality of other elements or components in addition to electronic circuit 100 . Moreover, in some embodiments, PCB 101 may not be used, and electronic circuit 100 may be integrated with other components of the electronic device without PCB 101 .
[0031] Examples of IC(s) include a System-On-Chip (SoC), an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Field-Programmable Gate Array (FPGA), a processor, a microprocessor, a controller, a Microcontroller Unit (MCU), or the like. Additionally, IC(s) may include a memory circuit or device such as a Random Access Memory (RAM) device, a Static RAM (SRAM) device, a Magnetoresistive RAM (MRAM) device, a Nonvolatile RAM (NVRAM), and/or a Dynamic RAM (DRAM) device such as Synchronous DRAM (SDRAM), a Double Data Rate (DDR) RAM, an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable ROM (EEPROM), etc. IC(s) may also include one or more mixed-signal or analog circuits, such as, for example, Analog-to-Digital Converter (ADCs), Digital-to-Analog Converter (DACs), Phased Locked Loop (PLLs), oscillators, filters, amplifiers, etc.
[0032] As such, electronic circuit 100 may include a number of different portions, areas, or regions. These various portions may include one or more processing cores, cache memories, internal bus(es), timing units, controllers, analog sections, mechanical elements, etc.
[0033] Although the example of FIG. 1 shows electronic circuit 100 in monolithic form, it should be understood that, in alternative embodiments, various systems and methods described herein may be implemented with discrete components. For example, in some cases, one or more discrete capacitors, inductors, transformers, transistors, registers, logic gates, etc. may be physically located outside of electronic circuit 100 (e.g., elsewhere on PCB 101 ).
[0034] FIG. 2 is a block diagram of an example of audio plug type detection circuit 200 residing within electronic circuit 100 of FIG. 1 . As illustrated, detection circuit 200 includes input(s)/output(s) 201 , audio input/output jack 202 , audio processor 203 , and audio codec 204 . Components 201 , 203 , and 204 may be operably coupled to one another via Inter-IC Sound (I 2 S) bus 205 or other suitable bus. Also, in some devices, detection circuit 200 may be coupled to timing circuit 206 , processing cores 207 A-N, memory 208 , and/or input/output (I/O) interface(s) 210 via bus 209 . In some cases, components 206 - 210 may be a part of another device (e.g., a computer, etc.) that is hosting audio circuit 200 .
[0035] It should be noted that different bus standards may be used to facilitate communication between different ones of the aforementioned components and/or between detection circuit 200 and components 206 - 210 . Moreover, in some cases, one or more of these components may be directly coupled to each other or embedded within each other (e.g., audio processor 203 may include audio codec 204 ). As such, it should be understood the particular configurations of audio circuit 200 and other components shown in FIG. 2 are provided for illustration purposes only, and that other configurations are possible.
[0036] In operation, audio processor 203 may act either independently or under command of processor core(s) 207 A-N to control one or more of components 201 - 204 (e.g., via I 2 S 205 ) in order to implement certain systems and methods for audio plug type detection. Audio codec 204 may implement one or more algorithms that compress and/or decompress audio data according to a given audio file format or streaming media audio format.
[0037] Processor core(s) 207 A-N may be any general-purpose or embedded processor(s) implementing any of a variety of Instruction Set Architectures (ISAs), such as the x86, RISC®, PowerPC®, ARM®, etc. In multi-processor systems, each of processor core(s) 210 A-N may commonly, but not necessarily, implement the same ISA.
[0038] Memory 208 may include for example, a RAM, a SRAM, MRAM, a NVRAM, such as “FLASH” memory, and/or a DRAM, such as SDRAM, a DDR RAM, an EPROM, an EEPROM, etc.
[0039] Bus 209 may be used to couple master and slave components together, for example, to share data or perform other data processing operations. In various embodiments, bus 209 may implement any suitable bus architecture, including, for instance, Advanced Microcontroller Bus Architecture® (AMBA®), CoreConnect™ Bus Architecture™ (CCBA™), etc. Additionally or alternatively, bus 209 may be absent and timing circuit 206 or memory 208 , for example, may be integrated into processor core(s) 207 A-N.
[0040] In some embodiments, input(s)/output(s) 201 may include, for example, ADCs, DACs, Phased Locked Loop (PLLs), oscillators, filters, amplifiers, etc. Particularly, input(s)/output(s) 201 may include one or more analog or digital input circuits configured to receive and/or preprocess, analog or digital audio signals (e.g., from a microphone, a line-in connection, an optical source, an S/PDIF line, etc.). In addition, input(s)/output(s) 201 may include one or more analog or digital output circuits configured to provide or output analog or digital audio signals to other devices, such as, for example, a loudspeaker, headphone, a line-out connection, an optical line, an S/PDIF line, etc.).
[0041] Audio jack 202 includes a cylindrical opening configured to receive an audio plug of one of a plurality of different types. Along the internal walls of the opening are four contacts 211 at positions corresponding to the tip (T), first Ring (R), second Ring (R), and sleeve (S) terminals of a TRRS audio plug, when one is inserted into the opening. Each of these four contacts 211 is electrically coupled to input(s)/output(s) 201 .
[0042] In various embodiments, modules or blocks shown in FIG. 2 may represent processing circuitry, logic functions, and/or data structures. Although these modules are shown as distinct blocks, in other embodiments at least some of the operations performed by these modules may be combined in to fewer blocks. Conversely, any given one of the modules of FIG. 2 may be implemented such that its operations are divided among two or more logical blocks. Although shown with a particular configuration, in other embodiments these various modules or blocks may be rearranged according to other suitable embodiments.
[0043] FIG. 3 are diagrams of examples of various audio plug types detectable according to some embodiments; and which show: TRS audio plug (3-pole) 300 A and corresponding contact diagram 300 B, TRRS audio plug (4-pole) 301 A, contact diagram 301 B for a standard TRRS audio plug, and contact diagram 301 C for an Open Mobile Terminal Platform (OMTP) TRRS audio plug.
[0044] TRS plug 300 A includes a Tip, Ring, and Sleeve contacts or terminals. Diagram 300 B shows that TRS plug 300 A carries the left audio channel at the Tip (L) and the right audio channel at the Ring (R), while the Sleeve terminal (G) is grounded. Also, a first impedance of approximately 16 to 1.5 kΩ between the Tip (L) and the Sleeve (G) represent a left speaker (e.g., of a headphone), and a second impedance of same value between the Ring (R) and the Sleeve (G) represent a right speaker.
[0045] TRRS plug 301 A includes a Tip, First Ring, Second Ring, and Sleeve contacts or terminals. Diagram 301 B shows that a standard TRRS plug carries the left audio channel at the Tip (L) and the right audio channel at the First Ring (R), the Second Ring (G) is grounded, and the Sleeve terminal (M) carries the microphone channel. A first impedance of approximately 16 to 1.5 kΩ between the First Ring (R) and the Second Ring (G) represents a right speaker and a second impedance of same value between the Tip (L) and the Second Ring (G) represent a left speaker. At third impedance of approximately 600 to 3 kΩ between the Second Ring (G) and the Sleeve (M) represent a microphone.
[0046] Still referring to TRRS plug 301 A, diagram 301 C shows that an OMTP TRRS plug also carries the left audio channel at the Tip (L) and the right audio channel at the First Ring (R), but the Second Ring (M) carries the microphone channel and the Sleeve terminal (G) is grounded. A first impedance of approximately 16 to 1.5 kΩ between the Tip (L) and the Sleeve (G) represents a left speaker and a second impedance of same value between the First Ring (R) and the Sleeve (G) represent a right speaker. At third impedance of approximately 600 to 3 kΩ between the Second Ring (M) and the Sleeve (G) represent a microphone.
[0047] FIG. 4 is a flowchart of method 400 for audio plug type detection. In various embodiments, method 400 may be performed in two stages, illustrated in FIGS. 5 and 6 , in order to detect, for example, which of plugs 300 B, 301 B, or 301 C is inserted into jack 202 of FIG. 2 .
[0048] A first stage of detection is performed by blocks 401 - 405 . At block 401 , method 400 grounds a sleeve terminal of the audio jack. At block 402 , method 400 applies an electrical current to a second ring terminal of the audio jack. At block 403 , method 400 measures a voltage between the second ring terminal and the sleeve terminal.
[0049] This first stage is illustrated at FIG. 5 , where diagram 500 B shows contacts 211 positioned relative to a TRS plug configuration with a current flowing from the Second Ring of contacts 211 to the ground terminal of plug 300 B. Diagram 501 B shows contacts 211 positioned relative to a standard TRRS plug configuration with a current flowing from the Second Ring of contacts 211 to the Microphone terminal (M) of plug 301 B through the microphone impedance. And diagram 501 C shows contacts 211 positioned relative to an OMTP TRRS plug configuration with a current also flowing from the Second Ring of contacts 211 to the Ground terminal (G) of plug 301 C, also through the microphone impedance.
[0050] At block 404 , method 400 makes an evaluation as to the magnitude of the measured voltage. In response to the magnitude of the voltage being approximately zero, block 405 determines that the audio plug is a 3-pole type. Conversely, in response to a magnitude of the voltage being greater than zero, method 400 determines that the audio plug is a 4-pole type, and moves on to a second stage of detection. In some implementations, the electrical current applied to the second ring of the audio jack may be of the order of 1 μA. The measured voltage may be either zero (in the case of TRS plug configuration 500 B) or it may be of the order of 500 mV (in the case of a TRRS plug configuration 501 B or 501 C).
[0051] In sum, the result of the first detection stage is a determination of whether the previously unknown audio plug is a 3-pole TRS plug or a 4-pole TRRS plug.
[0052] In a second, subsequent stage, method 400 grounds a tip terminal of the audio plug at block 406 . At block 407 , method 400 concurrently applies another electrical current to the sleeve terminal and to the second ring terminal of the audio plug. At block 408 , method 400 measures a first voltage between the sleeve terminal and the tip terminal. At block 409 , method 400 measures a second voltage between the second ring terminal and the tip terminal.
[0053] The second stage is illustrated at FIG. 6 , diagram 601 B shows contacts 211 positioned relative to a standard plug configuration with a first current flowing from the Sleeve of contacts 211 to the ground terminal of plug 301 B through the microphone impedance, and a second current flowing from the Second Ring of contacts 211 to the ground terminal of plug 301 B. Diagram 601 C shows contacts 211 positioned relative to an OMTP plug configuration with a first current flowing from the Sleeve of contacts 211 to the ground terminal of plug 301 C, and a second current flowing from the Second Ring of contacts 211 to the ground terminal of plug 301 C through the microphone impedance.
[0054] At block 410 , method 400 makes yet another evaluation. In response to a magnitude of the first voltage being greater than a magnitude of the second voltage, block 411 determines that the audio plug is a standard 4-pole audio plug. Conversely, in response to a magnitude of the first voltage being smaller than a magnitude of the second voltage, block 412 determines that the audio plug is an OMTP 4-pole audio plug.
[0055] In some embodiments, the first and second currents are the same—e.g., 1 μA—and difference between the first and second voltages is of the order of approximately 200 mV.
[0056] Accordingly, the result of the second detection stage is a determination of whether the 4-pole TRRS plug, assuming one has been detected in the first detection stage, is a standard type or an OMTP type.
[0057] It should be understood that the various operations described herein, particularly in connection with FIGS. 4-6 , may be implemented by processing circuitry or other hardware components. The order in which each operation of a given method is performed may be changed, and various elements of the systems illustrated herein may be added, reordered, combined, omitted, modified, etc. It is intended that this disclosure embrace all such modifications and changes and, accordingly, the above description should be regarded in an illustrative rather than a restrictive sense.
[0058] A person of ordinary skill in the art will appreciate that the various circuits depicted above are merely illustrative and is not intended to limit the scope of the disclosure described herein. In particular, a device or system configured to perform audio power limiting based on thermal modeling may include any combination of electronic components that can perform the indicated operations. In addition, the operations performed by the illustrated components may, in some embodiments, be performed by fewer components or distributed across additional components. Similarly, in other embodiments, the operations of some of the illustrated components may not be provided and/or other additional operations may be available. Accordingly, systems and methods described herein may be implemented or executed with other circuit configurations.
[0059] It will be understood that various operations discussed herein may be executed simultaneously and/or sequentially. It will be further understood that each operation may be performed in any order and may be performed once or repetitiously.
[0060] Many modifications and other embodiments of the invention(s) will come to mind to one skilled in the art to which the invention(s) pertain having the benefit of the teachings presented in the foregoing descriptions, and the associated drawings. Therefore, it is to be understood that the invention(s) are not to be limited to the specific embodiments disclosed. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
[0061] Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The terms “coupled” or “operably coupled” are defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless stated otherwise. The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that “comprises,” “has,” “includes” or “contains” one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations.
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Systems and methods for audio plug type detection excursion are described. In some embodiments, a method may include: receiving an audio plug at an audio jack; grounding a sleeve terminal of the audio jack; applying an electrical current to a second ring terminal of the audio jack; and measuring a voltage between the second ring terminal and the sleeve terminal. In other embodiments an electronic circuit may include a controller and a memory coupled to the controller, the memory having program instructions stored thereon that, upon execution by the controller, cause the controller to: ground a sleeve terminal of an audio jack; apply an electrical current to a second ring terminal of the audio jack; and measure a voltage between the second ring terminal and the sleeve terminal.
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This application is a Divisional of application Ser. No. 10/378,948 filed on Mar. 5, 2003 now U.S. Pat. No. 6,995,045, the entire contents of all are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a thin film transistor (TFT) and a method of forming the same. More particularly, the present invention relates to a TFT with non-transparent conductive structures under conducting wires that electrically couple with a drain/source, and a method of forming the TFT by using a mask with a slit pattern.
2. Description of the Prior Art
TFTs have been broadly used in contemporary electronic products such as switching on/off pixels in a liquid crystal display (LCD) panel. Hence, the topic of how to improve the structure and forming method for TFT has been popularly discussed.
A well-known TFT structure, as shown in FIG. 1 , at least includes following units over a substrate 10 : a conductive structure 11 , a first dielectric layer 12 , a first semi-conductive layer 13 , a second semi-conductive layer 14 , and a second dielectric layer 15 that is electrically coupled with a conducting wire 16 (patterned conductive structure). Herein, the conductive structure 11 is used as a gate. The first semi-conductive layer 13 is used as a channel and the second semi-conductive layer 14 can be used as a drain or a source. The first dielectric layer 12 and the second dielectric layer 15 are used as insulating and protective material. The conducting wire 16 is used in electrically coupling the drain with external circuits. However, FIG. 1 did not illustrate conducting wires, which electrically couple the gate and the source with external circuits. Basically, the source electrically coupled with external circuit via the conducting wire in the second dielectric layer, and the gate electrically coupled with external circuit via the conducting wire through the first and the second dielectric layer.
Obviously, five masks and pattern-transferred processes are essential for forming the TFT while each patterned layer requires corresponding mask and process, since the patterns of the conductive structure 11 , the first semi-conductive layer 13 , the second semi-conductive layer 14 , the second dielectric layer 15 and the conducting wire 16 are different from each other. Hence, many techniques for reducing required masks and processes have been continually brought out in order to save the material cost, to shorten the process time, and to improve the production ability.
For example, in a prior art, two masks were combined to form the one for forming the second semi-conductive layer 14 and the conducting wire 16 with the same material. However, the optimum cannot be achieved by using the same material since the requirements between the conducting wire and the source/drain are different. In another prior art, two masks were combined to form the one for forming the second dielectric layer 15 and the first semi-conductive layer 13 . By doing so, the problems such as higher leakage current (I off ) and drop height may be resulted from the structure of TFT size. In still another prior art, two masks were combined to form the one for forming the first semi-conductive layer 13 and the second semi-conductive layer 14 . However, the practical application can be quite difficult since the special exposure technique is required for the half tone mask. As to these techniques mentioned above can refer to as followings: A. Van Calster et. al. “A Simplified 3-Step Fabrication Scheme for high Mobility AMLCD Panels”; K. Ono et. al. “A Simplified 4 photo-Mask Process for 34-cm Diagonal TFT-LCDs” IDRC 1995; and Chang W. H. et. al. “A TFT Manufactured by 4-Msks Process with new Photolithography” IDRC 1998.
Besides, the light is transmitted to the TFT from the back of the substrate 10 while the TFT is used in a LCD panel, and the first dielectric layer 12 in a prior art is commonly the transparent material, hence the first semi-conductive layer 13 , the second semi-conductive layer 14 and the conducting wire 16 may induce the light current (such as the electron-hole pairs excited in semiconductor by the light) resulting to the problem of leakage current or noise.
As mentioned above, there is much space for improving a well-known structure and forming method for TFT. Hence, these problems of how to reduce the required mask in forming TFT process and how to prevent TFT from inducing the light current need to be solved.
SUMMARY OF THE INVENTION
According to the shortcomings mentioned in the background, the present invention provides a method for only using four masks in forming a TFT, and a TFT for preventing the light current effectively to improve the foregoing drawbacks.
One characteristic of the present invention is to use the same mask to define a source, a drain and a channel, and more particularly, using a mask with a slit pattern forms a non-uniform photoresist, as well as transfers patterns of the source, of the drain, and of the channel to corresponded semi-conductive layer.
Another characteristic of the present invention is that the TFT has a non-transparent conductive structure, which is at least positioned under the conducting wires of the source/drain/channel, beside and insulated with the gate. By doing so, the light transmitted from the substrate is blocked and the light current induced in the TFT is negligible.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows cross-sectional views of the well-known structure of a TFT;
FIGS. 2A to 2H show the basic processes in accordance with the present invention for forming a TFT;
FIGS. 3A to 3D show several assumed structures of the TFT in accordance with the present invention; and
FIGS. 4A to 4E show another basic processes in accordance with the present invention for forming a TFT
DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of the present invention is a method for forming a TFT, at least including the basic process steps described as below.
As shown in FIG. 2A , a substrate 20 is provided and a gate 21 is formed on the substrate 20 .
As shown in FIG. 2B , a dielectric layer 22 is formed on the substrate 20 and located over the gate 21 , and then a first semi-conductive layer 23 and a second semi-conductive layer 24 is formed in proper sequence on the dielectric layer 22 .
As shown in FIG. 2C , a photoresist layer 25 is formed on the second semi-conductive layer 24 , and then a mask 251 is placed over the photoresist layer 25 . Wherein the mask 251 has a slit pattern 252 , which is just over the gate 21 , and further, aims at the center of the gate 21 .
As shown in FIG. 2D , the photoresist layer 25 is patterned to form a photoresist pattern 253 , which is just over the gate 21 (or still over the substrate 20 around the gate 21 ). Wherein the photoresist pattern 253 further includes a thin photoresist pattern formed under the slit pattern 252 and a thick photoresist pattern, due to diffraction caused by the slit pattern 252 . However, the photoresist pattern 253 , in fact, has no obvious changes in its thickness but arc changes. This illustration is just drawn to stress one characteristic of the present embodiment, did not restrict the photoresist pattern 253 to form as described above.
As shown in FIG. 2E , portions of second semi-conductive layer 24 and first semi-conductive layer 23 without the photoresist pattern 253 covering are removed, as well the dielectric layer 22 without the photoresist pattern 253 covering can be removed at the same time. The present embodiment does not restrict these details.
As shown in FIG. 2F , the whole part of the thin photoresist pattern is removed. This can be achieved by using a non-selective etching process to lower the thickness of the whole photoresist pattern 253 until the second semi-conductive layer 24 exposed or only removing the thin part of the photoresist pattern 253 . The present embodiment does not restrict these details.
As shown in FIG. 2G , the portion of second semi-conductive layer 24 without the remained photoresist pattern 253 covering is removed, and then, the remained photoresist pattern 253 is removed. However, in accordance with forming different specifications of TFT, the first semi-conductive layer 23 without the remained photoresist pattern 253 covering also can be removed (or to be lowered) after removing the portions of second semi-conductive layer 24 .
As described above, the present embodiment uses the mask 251 with the slit pattern 252 to define the patterns of the first semi-conductive layer 23 and the second semi-conductive layer 24 at the same time, so that the required masks can be reduced in forming TFT process. The present embodiment uses the single mask 251 and turns the photoresist layer 25 into the non-uniform photoresist pattern 253 by applying the characteristic of a diffraction pattern, which results from slit diffraction and gradually weakens from its center to both sides. Further, the semi-conductive layers 23 and 24 are patterned by using the non-uniform photoresist pattern 253 through two process steps (one is to use the whole non-uniform photoresist pattern 253 ; the other one is to remove the thin photoresist pattern 253 and then use the remained photoresist pattern 253 ). By doing so, only using one mask in the present embodiment makes respective pattern on the second semi-conductive layer 24 and the first semi-conductive layer 23 .
Comparing the present embodiment with a well-known technique using the half tone mask, the basic process flows are the same for combining the photolithography processes of two semi-conductive layers by only using one mask. However, there is no extra requirement for special exposure processes but only some modifications on the mask since the present embodiment adopts silt diffraction. Hence, it is more convenient and saves the cost.
In order to form conducting wires to exchange signals with external circuits, the present embodiment, as shown in FIG. 2H , apparently can be further carried the processes out as followings: (These process steps are not described and illustrated in detail any more since they are not the characteristics of the present embodiment).
(1) After removing a portion of the second semi-conductive layer 24 , the photoresist pattern 253 is removed and then an extra dielectric layer 26 is formed over the substrate and covers the first semi-conductive layer 23 and the second semi-conductive layer 24 .
(2) The extra dielectric layer 26 is patterned to form an open region to expose the portion of the second semi-conductive layer 24 . Apparently, there is no effect on the dielectric layer 21 if covered or not by the photoresist pattern 253 before since the extra dielectric layer 26 covers it now.
(3) The patterned conductive structure 27 is formed on the extra dielectric layer 26 and is filled in the open region.
Another preferred embodiment in accordance with the present invention is a kind of TFT, as shown in FIG. 3A and FIG. 3B , at least including the basic units as followings: a conductive structure 31 , a non-transparent structure 32 , a first dielectric layer 33 , a first semi-conductive layer 34 , a second semi-conductive layer 35 , a second dielectric layer 36 and patterned semi-conductive layer 37 .
In the present embodiment, the conductive structure 31 is on the substrate 30 ; the non-transparent structure 32 is on the substrate 30 and electrically insulates from the conductive structure 31 (this is, the non-transparent structure 32 needs to be insulated from the conductive structure 31 while it is made of conductors, otherwise both of them can be connected together); the first dielectric layer 33 covers the substrate 30 , the conductive structure 31 and the non-transparent structure 32 ; the first semi-conductive layer 34 is on the first dielectric layer 33 , especially, on the conductive structure 31 and the non-transparent structure 32 ; the second conductive 35 is on a portion of the first semi-conductive layer 34 , especially, on the conductive structure 31 and the non-transparent structure 32 ; the second dielectric layer 36 covers the substrate 30 , the first semi-conductive layer 34 and the second semi-conductive layer 35 , further has an open region on the second dielectric layer 36 to expose a portion of the second semi-conductive layer 35 ; the patterned semi-conductive layer 37 is on the second dielectric layer 36 , further above the non-transparent structure 32 , and is filled in the open region.
Comparing both FIG. 3A and FIG. 3B with FIG. 1 , the obvious characteristic in the present embodiment is the existence of the non-transparent structure 32 . Referring to well-known techniques, the light current may be induced in the portions of the first semi-conductive layer 13 , the second semi-conductive layer 14 and the conducting wire 16 while the light is transmitted from the substrate 10 and these portions are not over the conductive structure 11 . In accordance with the present embodiment, the non-transparent structure 32 can effectively block and reduce the light transmitted from the substrate 30 in the first semi-conductive layer 34 , the second semi-conductive layer 35 and the patterned semi-conductive layer 37 . Further, the use of the non-transparent can solve the drawbacks such as light current. Hence, there is no need to change the materials and layouts for the first dielectric layer 33 , the first semi-conductive layer 34 , the second conductive 35 , the second dielectric layer 36 and the patterned semi-conductive layer 37 in the well-known TFT.
What is stressed here is that the present embodiment does not restrict the material to the non-transparent structure 32 , and it can be a conductor or a dielectric. However, in order to simplify the structure and the method of the present embodiment, the same material can be used in forming the non-transparent structure 32 and the conductive structure 31 (the gate); both the non-transparent structure 32 and the conductive structure 31 are formed at the same time while the semi-conductive layer covered on the substrate 30 is patterned (this is, adjusting the mask, which is used to form the gate, forms the non-transparent structure 32 and the conductive structure 31 ). Besides, a shorter distance taken electrically insulation into account between the non-transparent structure 32 and the conductive structure 31 is preferable in order to block the light as much as possible. For example, the TFT of the present embodiment is formed by following the method in accordance with the prior embodiment. This is, the non-transparent structure insulated form the gate is formed by the way as the gate formed, and at least positions under the remained portion of the first semi-conductive layer.
Further, in order to increase the portions, which are over both the non-transparent structure 32 and the conductive structure 31 , of the first semi-conductive layer 34 , the second conductive 35 and the patterned semi-conductive layer 37 to lower the possibility of the light current occurred, as shown in FIG. 3C and FIG. 3D , the present embodiment can make the portions over and along the edge of the conductive structure 31 wider than others no matter in the semi-conductive layers 34 or 35 ; the present embodiment also can make the portions over and along the edge of the non-transparent structure 32 wider than others no matter in the semi-conductive layers 34 or 35 .
Still another embodiment in accordance with the present invention is the method of forming TFT, at least including the basic process steps described as below.
As shown in FIG. 4A , a substrate 40 is provided, and a conductive structure 41 and a non-transparent structure 42 are formed on the substrate 40 . Herein, there is no any restriction on the distance or location between the conductive structure 41 and the non-transparent structure 42 but electrically insulation to each other. The conductive structure 41 and the non-transparent structure 42 do not be connected together while both of them are conductors. However, both of them can be connected together, as shown in FIG. 4B , while the non-transparent structure 42 is an insulator.
As shown in FIG. 4C , a first dielectric layer 43 is form on the substrate 40 and covers both the conductive structure 41 and the non-transparent structure 42 , and then a first semi-conductive layer 44 and a second semi-conductive layer 45 are formed in proper sequence on the first dielectric layer 43 .
As shown in FIG. 4D , the portions of the second semi-conductive layer 45 and the first semi-conductive layer 44 are removed, and the remained portions of the second semi-conductive layer 45 and the first semi-conductive layer 44 are at least over the conductive structure 41 . Of course, the present embodiment do not restrict the details of the pattern process but only requires to turn the structure shown in FIG. 4C into the one shown in FIG. 4D .
The first semi-conductive layer 44 , which is used as a channel to meet the TFT needs and is commonly made of semiconductor, is easy to induce the light current. Hence, the present embodiment makes the remained portion of the first semi-conductive layer 44 at least covers the portion of the non-transparent structure 42 . In addition, in order to reduce the change of the light transmitted from the substrate in the first semi-conductive layer 44 , the second conductive 45 and the patterned conductive structure 47 , the present embodiment can make the portions over and along the edge of the conductive structure 41 wider than others no matter in the semi-conductive layers 44 or 45 ; the present embodiment also can make the portions over and along the edge of the non-transparent structure 42 wider than others no matter in the semi-conductive layers 44 or 45 .
As shown in FIG. 4E , a second dielectric layer 46 is formed over the substrate 40 and covers the remained portions of the second semi-conductive layer 45 and the first semi-conductive layer 44 , and further forms an open region on the second dielectric layer 46 and exposes the portion of the second semi-conductive layer 45 . A patterned semi-conductive layer 47 is then formed on the second dielectric layer 46 and filled in the open region.
One characteristic, obviously, of the present embodiment is the process shown in FIG. 4A to form the conductive structure 41 and the non-transparent structure 42 on the substrate. The possibility of the induced light current resulted from the light transmitted from the substrate 40 can be substantially reduced by disposing the layout of the conductive structure 41 and the non-transparent structure 42 to make the first semi-conductive layer 44 and the second semi-conductive layer 45 (even the patterned semi-conductive layer 47 ) not only over the substrate 40 but also over the non-transparent structure 42 .
Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.
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The thin film transistor has a non-transparent structure besides and insulated with the gate. Hence, the light transmitted from the substrate is blocked and the light current induced in the thin film transistor is negligible. The method uses a mask with a slit pattern to form a non-uniform photoresist. Hence, the mask could be used to pattern two conductor layers for forming source/drain/channel.
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BACKGROUND OF THE INVENTION
The invention relates to power transistor structures in which a large number of individual elements are coupled in parallel to act as a single unit.
In linear applications, maximum transistor stress occurs at higher voltages when considerable power is being dissipated for longer than 1 ms. Because the emitter base voltage of bipolar transistors has a negative temperature coefficient, the tendency is for maximum conduction where temperature is highest. The resulting hot spot formation can become unstable, leading to secondary breakdown. This can be avoided by ensuring uniform conduction.
The problem of localization can be better understood by considering two parallel connected transistors. The following equations account for the transconductance and thermal effects. ##EQU1## Where: g m =base to collector transconductance
q=electron charge
k=Boltzmann's constant
T=Absolute temperature
θ j =Thermal resistance of the transistor
φ B =Temperature coefficient of the transistor base to emitter voltage.
I C =Collector Current
V CE =Collector to emitter voltage
V BE =Base to emitter voltage.
Current sharing becomes potentially unstable when V BE decreases with increasing I C . Without ballasting, this can occur for a temperature rise greater then 10° C. These equations are only valid when the g m of the parallel connected transistors is equal. Once an instability is initiated, the mathematical description is less concise. The process exhibits hysteresis, and the destabilization will persist until ΔT is reduced to some lower value.
The situation can be improved with resistive ballasting in which a resistor is inserted in series with each emitter element. (A base ballast resistor can be moved to the emitter for analysis by dividing its resistance by transistor current gain.) The following related equations show that sufficient conditions for stability are simple and straightforward. ##EQU2## Where: R bal is the ballast resistance
V bal is the voltage across the ballast resistor
V B is the combined V bal and V BE .
A fraction of volt drop across the ballast resistor will insure uniform conduction for ΔT=300° C., even if low level injection is assumed (φ B =2.5 mV/°C.) and mutual thermal coupling between elements is ignored. This shows the forward biased secondary breakdown can be completely eliminated for any reasonable set of operating conditions, suffering only an insignificant increase in transistor losses.
Standard bipolar power transistors rely upon high level effects rather than ballast to reduce g m and φ B . The high level threshold can be lowered by using wide emitters and thick, lightly doped bases; but the improvement available is rather limited. Such structures are inherently slow. Single-diffused transistors also have the collector-base junction located close to the heat sink, which reduces thermal resistance and improves thermal coupling among elements.
SUMMARY OF THE INVENTION
It is an object of the invention to create a power transistor in which secondary breakdown is avoided by base resistor ballasting of the individual parallel connected elements that make up the structure.
It is a further object of the invention to incorporate a junction field effect transistor into the base of an element in a plural element power transistor whereby the collector voltage modulates the series base resistance which acts as a ballast.
These and other objects are realized using a cell structure that involves plural parallel-connected individual transistors. Each transistor is represented by a separate emitter diffused into a common base region. Opposing edges of the base region are coupled to a spaced apart base connection by means of an ion-implanted resistance layer, the backside of which forms a PN junction with the transistor collector. This means that the collector potential will deplete the resistor which will then be voltage variable as a function of collector voltage. The resistor thickness and doping density are established so that the resistor pinches off completely above the maximum collector voltage rating for the transistor. If desired, the resistor can be made to pinch off at a voltage below the maximum collector voltage and to include a short section of more highly doped material which acts as a shunt resistor. With this construction the resistor acts as if there were a shunt fixed section so that at pinch off the resistance goes up to some fixed value not infinity.
When a large number of such cells are parallel connected, the resulting device is base resistance ballasted with variable resistors that adjust themselves as a function of collector voltage. The resulting power transistor does not display the secondary breakdown characteristic. Such a device can be operated within its power rating at any desired collector voltage below BV CEO without concern for instabilities.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows the cell layout of the invention.
FIG. 2 is a cross-section of the cell of FIG. 1 taken at line 2--2.
FIG. 3 is a schematic diagram of the cell of FIG. 1.
FIG. 4 is a graph plotting the resistance of the FET of FIG. 3 as a function of collector voltage.
DESCRIPTION OF THE INVENTION
FIG. 1 shows the topography of one form of power transistor cell constructed in accordance with the invention. FIG. 2 is a cross-section of the FIG. 1 structure taken at line 2--2. It is to be understood that the drawing is not to scale. In particular FIG. 2 is exaggerated dimensionally in order to better illustrate the invention. Also while the drawing shows four individual emitters, more or fewer could be used.
The transistor is constructed on an N + type wafer 20, a fragment or chip of which is shown at 10. The substrate is of low resistivity to reduce series resistance and has an epitaxial surface layer 21 of a resistivity suitable for a transistor collector. In FIG. 1 the contact metallization has been omitted for clarity.
As shown in FIG. 2, the chip 10 is coupled to a heat sink surface 22 which also serves as a collector connection. This arrangement is typical of a double diffused bipolar silicon transistor. For example, heat sink 22 may be the typical T0-3 power transistor package. One complete power transistor cell is shown in FIG. 1 along with a portion of each of the adjacent cells. The central square 11 represents a transistor base diffusion of P-type conductivity normally created by a boron diffusion that typically extends about three microns into the semiconductor N-type epitaxial layer 21.
Four heavily doped emitters 12 are shown diffused into base 11. These emitters are small so that they individually have high frequency capability and a large periphery to area ratio. The dashed lines 13 inside the emitters represent the areas where the planar oxide will be removed and contact made to the silicon. It can be seen that a metallization finger 24 (not shown in FIG. 1) extended vertically on the drawing could be used to parallel connect all of the emitters in a plurality of cells in a row.
A pair of contact busses 14 and 15 are formed with P-type diffusions to extend across the device. They are spaced apart from base 11 and extend parallel with the edges thereof as shown. Two resistive strips 16 and 17 span the region between base 11 and busses 14 and 15 respectively. These resistive regions are preferably created using ion implantation to control their impurity content, but they are typically diffused after implantation so that they extend below the semiconductor surface to about the same extent as the base region 11. It can be seen that the undersides of resistors 16 and 17 will face the transistor N-type collector. Therefore the collector bias voltage will act to deplete or pinch off the resistors. This means that resistors 16 and 17 are voltage variable as a function of collector voltage and are coupled in series with base 11. Diffused busses 14 and 15 will be contacted by metallization 23 (not shown in FIG. 1) that will contact the silicon through contact 19 which is shown in dashed outline in FIG. 1.
Since resistors 16 and 17 are voltage variable and may pinch off completely within the normal transistor collector voltage, a more heavily doped section 18 is included within resistor 16. This section would ordinarily be created by an additional ion implant that will dope it sufficiently to raise its pinch off voltage above that of the transistor rating.
Section 18 can be regarded as a resistor that shunts the voltage variable resistor as shown in FIG. 3. This drawing is a schematic representation of the cell of FIG. 1. As can be seen, a bipolar junction transistor Q 1 has its base driven through a junction field effect transistor Q 2 which has resistor 18 in parallel between its source and drain. Q 2 has its gate connected to the collector of Q 1 because these devices are commonly fabricated into the silicon. As a practical matter resistor 18 could be portrayed as a second field effect transistor connected in parallel with Q 2 . However, if the pinch off of this second device is never exceeded, it will always be on and will act like a shunt resistor.
FIG. 4 is a graph that plots resistance as a function of voltage for a typical cell as shown in FIG. 1. It will be noted that at the lower voltage the resistance is about 1K ohms and rises with voltage to about 15K ohms which is the value of resistor 18.
EXAMPLE
Power transistors were constructed using the cell structure of FIG. 1. Typical die size was a 185 mil square with 316 such cells connected in parallel for a total of 1264 emitters. The resulting devices can dissipate 250 watts at voltages above 200 V. At 10 amperes the collector saturation was typically less than 1 volt. The f T was over 50 MHz. Two different structures were prepared and optimized for different voltages by selecting the thickness and resistivity of layer 21. In the 200 volt version the typical current gain at ten amperes was about 25. In the 60 volt version the current gain was about 75 at ten amperes.
Neither structure displayed any secondary breakdown instabilities within their respective voltage ratings up to 250 watts.
The invention has been described and operating examples detailed. When a person skilled in the art reads the foregoing, there are alternatives and equivalents that will become apparent that are within the spirit and intent of the invention. Accordingly, it is intended that the scope of the invention be limited only by the following claims.
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A power transistor design that eliminates thermally initiated secondary breakdown in fast, double-diffused transistors is described. The power dissipation capability is made independent of collector voltage, avoiding safe area restrictions below 0.9 BV CBO .
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/608,372, filed Mar. 8, 2012, the disclosures of which are fully incorporated herein by reference for all purposes.
TECHNICAL FIELD
The present application relates generally to implantable medical stimulators and more particularly to a paddle lead having a plurality of electrodes wherein the lead is shaped to facilitate the insertion of paddle lead within the epidural space.
BACKGROUND
Neurostimulation systems are devices that generate electrical pulses and deliver the pulses to nerve tissue to treat a variety of disorders. Neurostimulation systems generally include a pulse generator and one or more leads. The pulse generator is typically implemented using a metallic housing that encloses circuitry for generating the electrical pulses, control circuitry, communication circuitry, a rechargeable battery, etc. The pulse generation circuitry is coupled to one or more stimulation leads through electrical connections provided in a “header” of the pulse generator. Specifically, feed-through wires typically exit the metallic housing and enter into a header structure of a moldable material. Within the header structure, the feed-through wires are electrically coupled to annular electrical connectors. The header structure holds the annular connectors in a fixed arrangement that corresponds to the arrangement of terminals on a stimulation lead.
Spinal cord stimulation (SCS) is an example of neurostimulation in which electrical pulses are delivered to nerve tissue in the spine typically for the purpose of chronic pain control. While a precise understanding of the interaction between the applied electrical energy and the nervous tissue is not fully appreciated, it is known that application of an electrical field to spinal nervous tissue can effectively mask certain types of pain transmitted from regions of the body associated with the stimulated nerve tissue. Specifically, applying electrical energy to the spinal cord associated with regions of the body afflicted with chronic pain can induce “paresthesia” (a subjective sensation of numbness or tingling) in the afflicted bodily regions. Thereby, paresthesia can effectively mask the transmission of non-acute pain sensations to the brain.
Also, each exterior region, or each dermatome, of the human body is associated with a particular spinal nerve root at a particular longitudinal spinal position. The head and neck regions are associated with C2-C8, the back region extends from C2-S3, the central diaphragm is associated with spinal nerve roots between C3 and C5, the upper extremities correspond to C5 and T1, the thoracic wall extends from T1 to T11, the peripheral diaphragm is between T6 and T11, the abdominal wall is associated with T6-L1, lower extremities are located from L2 to S2, and the perineum from L4 to S4. In conventional neurostimulation, when a patient experiences pain in one of these regions, a neurostimulation lead is implanted adjacent to the spinal cord at the corresponding spinal position.
Positioning of an applied electrical field relative to a physiological midline is also important. Nerve fibers extend between the brain and nerve root along the same side of the dorsal column as the peripheral areas of the fibers represent. Pain that is concentrated on only one side of the body is “unilateral” in nature. To address unilateral pain, electrical energy is applied to neural structures on the side of a dorsal column that directly corresponds to a side of the body subject to pain. Pain that is present on both sides of a patient is “bilateral.” Accordingly, bilateral pain is addressed through application of electrical energy along both sides of the column and/or along a patient's physiological midline.
Percutaneous leads and laminotomy leads are the two most common types of lead designs that provide conductors that deliver stimulation pulses from an implantable pulse generator (IPG) to distal electrodes adjacent to the nerve tissue. As shown in FIG. 1A , conventional percutaneous lead 100 includes electrodes 101 that substantially conform to the body of the body portion of the lead. Due to the relatively small profile of percutaneous leads, percutaneous leads are typically positioned above the dura layer through the use of a Touhy-like needle. Specifically, the Touhy-like needle is passed through the skin, between desired vertebrae to open above the dura layer for the insertion of the percutaneous lead.
As shown in FIG. 1B , conventional laminotomy or paddle lead 150 has a paddle configuration and typically possesses a plurality of electrodes 151 arranged in one or more columns. Multi-column laminotomy leads enable reliable positioning of a plurality of electrodes. Also, laminotomy leads offer a more stable platform that tends to migrate less after implantation and that is capable of being sutured in place. Laminotomy leads also create a uni-directional electrical field and, hence, can be used in a more electrically efficient manner than conventional percutaneous leads. Due to their dimensions and physical characteristics, conventional laminotomy leads require a surgical procedure for implantation. The surgical procedure (a partial laminectomy) is evasive and requires the resection and removal of certain vertebral tissue to allow both access to the dura and proper positioning of a laminotomy lead.
SUMMARY
Some representative embodiments are directed to the use of a paddle structure to apply electrical stimulation to spinal nervous tissue to treat a variety of diseases and/or conditions, for example pain or chronic pain. A stimulation paddle lead is implanted in the patient with electrodes in the epidural space of the patient. The paddle portion of the paddle lead is elongated shaped with the distal end of the paddle having a tabbed or extended portion with the leads exiting the extended portion of the paddle an angle relative to the longitudinal axis of the paddle.
The foregoing has outlined rather broadly certain features and/or technical advantages in order that the detailed description that follows may be better understood. Additional features and/or advantages will be described hereinafter which form the subject of the claims. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the appended claims. The novel features, both as to organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B depict a conventional percutaneous lead and a convention paddle lead.
FIG. 2 depicts a planar view of a paddle lead according to one representative embodiment.
FIG. 3 depicts a system for implantable pulse generator with a paddle lead in communication with a wireless programming device according to one representative embodiment.
FIG. 4 depicts a stimulation paddle according to another representative embodiment.
FIG. 5 depicts a stimulation paddle according to yet another representative embodiment.
FIG. 6 depicts a stimulation paddle according to another representative embodiment.
DETAILED DESCRIPTION
Referring now to FIG. 2 , there is depicted a laminotomy lead 200 that can be used for spinal cord stimulation or stimulation of spinal nervous tissue to treat a variety of diseases and/or conditions, for example, but not limited to pain (e.g., peripheral pain), more specifically chronic pain, CRSII or CRSI. Laminotomy or paddle lead 200 includes proximal end 210 and distal end 220 . Proximal end 210 includes a plurality of electrically conductive terminals 212 . Distal end 220 includes a plurality of electrically conductive electrodes 222 (only 3 of the electrodes have been annotated for the sake of clarity) arranged within a flat, thin, paddle-like structure 230 . The electrodes 220 are mutually separated by insulative material of the paddle. The paddle structure 230 itself may have a width such that it spans the entire dorsal column or fits within the epidural space. Those of skill in the art are cognizant that the size of the dorsal column and epidural space can vary among individuals as well as within an individual. Thus, depending upon the desired implantation site, thoracic or cervical, a paddle structure may be designed to fit into the desired space such that it at least covers the anatomical and physiological midline of the patient.
Since the paddle structure 230 can be as wide as the dorsal column or epidural space, the electrodes 222 likewise may have a width such that the combination of the size and number of electrodes span the width of paddle. The width of the electrode array can be a width that spans the anatomical and physiological midline. The length of the electrodes may vary as well such that the length comprises a length that is appropriate for the length of the paddle structure. In one such example, but not by way of limitation, the paddle structure 230 has a width of about 11 mm with the electrodes 222 having an approximate width of about 0.5 mm to about 1.5 mm, or any range there between, more particularly; the width of the electrode can be about 1 mm having an approximate electrode array width of about 9 mm.
Yet further, the spacing of the electrodes 222 may vary as well depending upon the paddle structure and the desired usage or placement of the structure. For a paddle structure 230 adapted for implantation within a cervical vertebral level, good results have been achieved with the electrodes being spaced apart approximately 1.5 mm laterally and 2.5 mm longitudinally. For a paddle structure 230 adapted for implantation within a thoracic vertebral level, good results have been achieved with the electrodes 222 being spaced apart by 1.0 mm laterally and 2 mm to 3 mm longitudinally. Conductors 240 (which are embedded within the insulative material of the lead body) electrically connect electrodes 222 to terminals 212 .
Terminals 212 and electrodes 222 are preferably formed of a non-corrosive, highly conductive material. Examples of such material include stainless steel, MP35N, platinum, and platinum alloys. In a preferred embodiment, terminals 212 and electrodes 222 are formed of a platinum-iridium alloy. Each conductor 240 is formed of a conductive material that exhibits desired mechanical properties of low resistance, corrosion resistance, flexibility, and strength. While conventional stranded bundles of stainless steel, MP35N, platinum, platinum-iridium alloy, drawn-brazed silver (DBS) or the like can be used, a preferred embodiment uses conductors 240 formed of multi-strands of drawn-filled tubes (DFT). Each strand is formed of a low resistance material and is encased in a high strength material (preferably, metal). A selected number of “sub-strands” are wound and coated with an insulative material. With regard to the operating environment of representative embodiments, such insulative material protects the individual conductors 240 if its respective sheath 242 was breached during use.
In addition to providing the requisite strength, flexibility, and resistance to fatigue, conductors 240 formed of multi-strands of drawn-filled tubes, in accordance with the above description, provide a low resistance alternative to other materials. Specifically, a stranded wire, or even a coiled wire, of approximately 60 cm and formed of MP35N or stainless steel or the like would have a measured resistance in excess of 30 ohms. In contrast, for the same length, a wire formed of multi-strands of drawn-filled tubes could have a resistance less than 4 ohms.
Sheaths 242 and paddle structure 230 are preferably formed from a medical grade, substantially inert material, for example, polyurethane, silicone, or the like. Importantly, such material should be non-reactive to the environment of the human body, provide a flexible and durable (i.e., fatigue resistant) exterior structure for the components of paddle lead 200 , and insulate adjacent terminals 212 and/or electrodes 222 . Additional structure (e.g., a nylon mesh, a fiberglass substrate) (not shown) can be internalized within the paddle structure 230 to assume a prescribed cross-sectional form.
FIG. 3 depicts paddle lead 200 coupled to IPG 300 which is in wireless communication with programmer device 310 . An example of a commercially available IPG is the Eon™ Rechargeable IPG manufactured by Advanced Neuromodulation Systems, Inc, although any suitable IPG, such as RF powered devices, could be alternatively employed. As shown in FIG. 3 , paddle lead 200 is coupled to the headers ports 302 of IPG 300 . Each header port 302 electrically couples the respective terminals 212 (shown in FIG. 2 ) to a switch matrix (not shown) within IPG 300 .
The switch matrix selectively connects the pulse generating circuitry (not shown) of IPG 300 to the various terminals 212 , and, hence to the electrodes 222 . The sealed portion 304 of IPG 300 contains the pulse generating circuitry, communication circuitry, control circuitry, and battery (not shown) within an enclosure to protect the components after implantation within a patient. The control circuitry may comprise a microprocessor, one or more ASICs, and/or any suitable circuitry for controlling the pulse generating circuitry. The control circuitry controls the pulse generating circuitry to apply electrical pulses to the patient via electrodes 222 of paddle lead 200 according to multiple pulse parameters (e.g., pulse amplitude, pulse width, pulse frequency, etc.). The electrodes 222 are set to function as cathodes or anodes or set to a high-impedance state for a given pulse according to the couplings provided by the switch matrix. The electrode states may be changed between pulses.
When paddle lead 200 is initially implanted within the patient, a determination of the set(s) of pulse parameters and the electrode configuration(s) that effectively treat the patient's condition is made. The determination or programming typically occurs through a physician's interaction with configuration software 312 executed on the programmer device 310 . Configuration software 312 steps the physician through a number of parameters and electrode configurations. In preferred embodiments, the electrode configurations are stepped through by laterally “steering” the electrical field by moving the anodes and/or cathodes along a row of the paddle as discussed above. The patient provides feedback to the physician regarding the perceived stimulation that occurs in response the pulse parameters and electrode configuration(s). The physician effects changes to the parameters and electrode configuration(s) until optimal pulse parameters and electrode configuration(s) are determined. The final pulse parameters and configurations are stored within IPG 300 for subsequent use. The pulse parameters and configurations are used by IPG 300 to control the electrical stimulation provided to the patient via paddle lead 200 .
As depicted in FIG. 4 , paddle structure 230 includes an array of electrodes 222 that are spaced apart longitudinally along the length of paddle structure 230 from end 250 towards end 252 , and are spaced apart across the width of paddle structure 230 . The spacing of the electrodes 222 can be set accordingly to the target implant site and the needed stimulation. Paddle structure 230 further includes suture holes 270 which permit the suturing of paddle structure 230 to the patient after implantation to help anchor the paddle lead 200 at the target location.
Paddle structure 230 includes a tabbed or extended curved portion 260 that extends generally perpendicular from the length side 232 at end 252 of paddle structure 230 . Leads 244 are connected to paddle structure 230 at tabbed portion 260 and connect thereto in a generally perpendicular manner with respect to the length of paddle structure 230 .
While tabbed portion 260 is depicted as a generally uniform curved shaped, those skilled in the art will recognize that tabbed portion 260 could be shaped to more particularly conform to a user's preference or to further conform to the targeted epidural space.
Referring now to FIG. 5 , there is depicted another representative embodiment of a paddle structure 230 . As with the embodiment illustrated in FIG. 4 , paddle structure 230 includes an array of electrodes 222 that are spaced apart longitudinally along the length of paddle structure 230 from end 250 towards end 252 , and are spaced apart across the width of paddle structure 230 . The spacing of the electrodes 222 can be set accordingly to the target implant site and the needed stimulation.
Paddle structure 230 includes a tabbed or extended curved portion 261 that extends generally perpendicular from the length side 233 (opposite side 232 of FIG. 4 ) at end 252 of paddle structure 230 . Leads 244 are connected to paddle structure 230 at tabbed portion 260 and connect thereto in a generally perpendicular manner with respect to the length of paddle structure 230 .
As with the embodiment depicted in FIG. 4 , while tabbed portion 260 is depicted as a generally uniform curved shaped, those skilled in the art will recognize that tabbed portion 260 could be shaped to more particularly conform to a user's preference or to further conform to the targeted epidural space.
Referring now to FIG. 6 , there is depicted another representative embodiment of a paddle structure 230 . As with the embodiments illustrated herein above, paddle structure 230 includes an array of electrodes 222 that are spaced apart longitudinally along the length of paddle structure 230 from end 250 towards end 252 , and are spaced apart across the width of paddle structure 230 . The spacing of the electrodes 222 can be set accordingly to the desired target implant site and the desired stimulation.
Paddle structure 230 includes a tabbed or extended curved portion 262 that extends at an obtuse angle with respect to the length of the paddle structure 230 from the side 233 (opposite side 232 of FIG. 4 ) at end 252 of paddle structure 230 . Leads 244 are connected to paddle structure 230 at tabbed portion 260 and connect thereto also at an obtuse angle with respect to the length of paddle structure 230 .
As with the embodiment depicted above, while tabbed portion 262 is depicted as a generally uniform curved shaped, those skilled in the art will recognize that tabbed portion 262 could be shaped to more particularly conform to a user's preference or to further conform to the targeted epidural space. In addition, it is anticipated that tabbed portion 262 could extend from side 233 .
When paddle lead 200 is to be implanted within a patient, a laminotomy is performed on the patient wherein at least a portion of the lamina of the vertebral bone is removed to provide access to the epidural space at the site of the target insertion of paddle lead 200 . The implanter holds the paddle structure 230 , at least partially by the tabbed portion ( 260 , 261 , 262 ) to facilitate the insertion of paddle structure 230 , into the epidural space of the patient so that the electrodes 222 are placed over the midline of the spinal cord, with end 250 being inserted first.
The tabbed portion ( 260 , 261 , 262 ) along with the configuration of the connection of leads 244 to paddle structure 230 facilitate the insertion of the paddle structure 230 into the epidural space, at least in part, by permitting the implanter to easily grab paddle portion 230 from the side at the tab ( 260 , 261 , 262 ) and line-up the midline of the paddle structure 230 with the midline of the spinal cord while also permitting implanter's hand to be offset from the midline of the spinal cord. Additionally, leads 244 being connected to the tabbed portion ( 260 , 261 , 262 ) and extending from the paddle structure 230 at an angle with respect to the longitudinal midline of paddle portion 230 substantially reduces or even eliminates interference caused from close proximity of the contiguous vertebrae at the site of the laminectomy.
In addition to facilitating the implantation of the paddle portion 230 of paddle lead 200 into the epidural space, the configuration of the connection of the leads 244 to the paddle portion 230 at an angle with respect to the longitudinal midline of paddle portion 230 inhibits the movement or migration of paddle portion 230 after completion of the implantation as the leads 244 to not have to be bent around the adjacent lamina at the site of the laminectomy.
Although certain representative embodiments and advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate when reading the present application, other processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the described embodiments may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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An implantable stimulation system including an epidural lead for spinal cord stimulation that includes a paddle having an array of electrodes coupled to conductors within the paddle body. The paddle is elongated in shaped with the distal end of the paddle having a tabbed or extended portion with the lead exiting the extended portion of the paddle an angle relative to the longitudinal axis of the paddle.
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BACKGROUND OF THE INVENT-ON
1. Field of the Invention
The present invention involves devices for folding sheets of paper, such as documents, and in particular to devices capable of producing two or more folds in a sheet of paper.
2. Description of Related Art
There are two primary methods of generating folds in paper. These are commonly called "buckle folding" and "knife folding". As shown in FIG. 1A, buckle folders function by driving a sheet of paper S with drive rollers 2,4 through a fold chamber 8 against a stop 10, and allowing a controlled buckle to form within an appropriately designed set of baffles. This buckle is drawn into a nip by a pair of fold rollers 4,6. These rollers usually contact the sheet along most of its width and have a high normal force to insure a tight fold. Knife folders, as shown in FIG. 1B, work by registering one or more sheets S adjacent a pair of fold rollers 4,6 by contacting an edge of the sheet S against a stop 10 and then deflecting the sheet(s) S into the fold nip using a moving "knife edged" bar 12 which is moved in the direction K as shown in FIG. 1B.
Knife folders have been commonly used to perform single folds on saddle stitched sets of paper, and buckle folders are often designed with two or more fold stations placed sequentially to perform more complex folds. Two commonly used complex folds include "letter folds", in which 8.5 × 11 inch or "letter" size sheets are folded twice as shown in FIG. 2A. These folders are often used in conjunction with direct mail systems which automatically insert the folded sheets into envelopes. A second common complex fold is called a "Z" fold and is usually performed on A3 or 17 inch size sheets (S") to enable the insertion of these large sheets within a set of A4 or 8.5 × 11 inch size paper (S'). As shown in FIG. 2B, this type of fold makes the use and handling of large size sheets much simpler and practical by folding them so that their outer dimensions match those of standard letter size paper.
U.S. Pat. No. 4,717,134 to Iida et al. discloses a sheet folding apparatus including a plurality of sheet processing units each having a pair of folding rollers, a deflector and a fold position controlling chamber. The apparatus can produce two-fold, Z-fold and reverse Z-fold sheets. In a Z-fold mode, a sheet is guided by a first sheet deflector into a first fold chamber until stopped by a stopper A buckle is formed and gripped by a first roller couple to form a first fold therein. The sheet now having one fold is guided by a second deflector to a second fold chamber until stopped by a second stopper. Another buckle is formed and gripped by a second roller couple to form a second fold therein. The sheet is then guided by a third deflector to a third stage roller couple and transported through a third passage to an outlet.
FIG. 3 illustrates a Z-fold producing sheet folder similar to that disclosed in the above-referenced U.S. Pat. No. 4,717,134. A sheet traveling along feed path F is moved into folding apparatus 20 by a pair of rollers 22. A first deflector 24 either allows the sheet to bypass the folding apparatus and exit through rollers 26 or is actuated to deflect the sheet through passage 27 and into fold chamber 28. A plurality of stoppers, or gates, 30a-d are provided in fold chamber 28 and are selectively moved into fold chamber 28 to engage a lead edge of a sheet to control the location of a first fold to be formed in the sheet. Gates 30a-d are also selectively engaged depending on the size of the sheet being folded. Once the sheet is stopped by one of gates 30a-d a buckle is formed and captured in the nip between rollers 32,34 to form a first fold in the sheet. Deflector 36 either deflects the sheet so that it passes through rollers 34,38 and into passage 43 to exit through rollers 26, or is moved out of the path of the sheet so that the sheet can enter second fold chamber 40. Depending on the size of the sheet and the desired location of a second fold to be placed in the sheet, one of gates 42a,42b is moved into fold chamber 40 to stop the forward movement of the oncefolded sheet therein. A second buckle then forms in the sheet and is captured in the nip between rollers 34,38 to form a second fold in the sheet. The sheet is then conveyed through passage 43 to exit rollers 26 Thus, in order to form a Z-fold in a sheet of paper, two fold plates 28,40 and two sets of fold rollers 32,34 and 34,38 consisting of at least three rollers is required Additionally, a considerable amount of vertical space (about 27 inches) is required to contain the various passages and rollers of this prior art Z-folder.
U.S. Pat. No. 4,905,977 to Vijuk discloses a sheet folding apparatus which places Z-folds or letter folds in one or more sheets. This device includes a first stopper member for stopping the passage of one or more sheets along a paper path, a knife for forcing the stopped sheet through a slot and into a first pair of fold rollers, a second stopper for stopping the once-folded sheet(s) and a second pair of fold-forming rollers for placing a second fold in the sheets.
U.S. Pat. No. 4,900,391 to Mandel et al. discloses a recirculating folder for direct mail application. A two fold chamber, three fold roller arrangement similar to that described with reference to FIG. 3 is used to place a letter fold in one or more sheets. These sheets are then recirculated to a "wait station" where they are temporarily held and then inserted into an enveloping forming sheet which is then folded and glued to form an envelope filled with insert material which is "ready-to-mail".
U.S. Pat. No. 4,518,380 to Shimizu et al discloses a paper folding device capable of placing only a single fold in a sheet of paper.
U.S. Pat. No. 4,586,704 to Lehmann et al. discloses a folding machine for placing two folds in a sheet. The machine of Lehmann et al. includes two folding pockets and at least two pairs of folding cylinders to place two folds in a sheet of paper.
U.S. Pat. No. 4,455,081 to Yoshimura et al. discloses an apparatus for placing a single fold in sheets of paper.
U.S. Pat. No 3,804,399 to Rupp discloses a sheet folding apparatus which includes two fold plates and at least three fold rollers to form two folds in a sheet.
The disclosed apparatus may be readily operated and controlled in a conventional manner with conventional control systems. Some additional examples of control systems for various prior art copiers with document handlers, including sheet detecting switches, sensors, etc., are disclosed in U.S. Pat. Nos.: 4,054,380; 4,062,061; 4,076,408; 4,078,787; 4,099,860; 4,125,325; 4,132,401; 4,144,550; 4,158,500; 4,176,945; 4,179,215; 4,229,101; 4,278,344; 4,284,270, and 4,475,156. It is well known in general, and preferable, to program and execute such control functions and logic with conventional software instructions for conventional microprocessors. This is taught by the above and other patents and various commercial copiers. Such software will of course vary depending on the particular function and the particular software system and the particular microprocessor or microcomputer system being utilized, but will be available to or readily programmable by those skilled in the applicable arts without undue experimentation from either verbal functional descriptions, such as those provided herein, or prior knowledge of those functions which are conventional, together with general knowledge in the software and computer arts. Controls may alternatively be provided utilizing various other known or suitable hardwired logic or switching systems.
All references cited in this specification, and their references, are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features, and/or technical background.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for placing one or more folds in a sheet of paper which is simple in construction and inexpensive to build.
It is another object of the present invention to provide an apparatus for placing two or more folds in a sheet of paper which includes fewer parts than previous folding apparatus.
It is another object of the present invention to provide an apparatus for placing two or more folds in a sheet of paper which is less likely to jam and easier to clear if jammed than previous folding apparatus.
It is a further object of the present invention to provide an apparatus for placing two or more folds in a sheet of paper which requires only a single fold position controlling chamber and one pair of fold producing rollers.
To achieve the foregoing and other objects, and to overcome the shortcomings discussed above, a sheet folding apparatus is disclosed which includes an inlet for receiving a sheet material from outside of the sheet folding apparatus, an outlet for discharging the sheet material to outside of the sheet folding apparatus, and a folding mechanism within the apparatus for placing one or more folds in the sheet material. The folding mechanism includes a fold position controlling chamber having first and second ends and including at least one fold plate stop spaced from said first end for blocking the fold position controlling chamber, first and second fold producing rollers contacting each other at peripheral surfaces thereof and located adjacent the first end of the fold position controlling chamber for withdrawing a sheet from the fold position controlling chamber and placing a fold therein and a recirculation passage extending around the periphery of one of the first and second fold producing rollers so that a sheet can be conveyed around the outer periphery thereof and be inserted back into the fold position controlling chamber after being withdrawn from the fold position controlling chamber by the first and second fold producing rollers. The once-folded sheet can then be directed to the outlet or back through the first and second fold producing rollers to place a second fold therein.
This structure permits one or more folds to be placed in sheet material while requiring only a single fold position controlling chamber and one pair of fold producing rollers. By placing a plurality of fold plate stops at various locations along the length of the fold position controlling chamber, the number and locations of the folds for a variety of sheet sizes can be precisely controlled. The present invention can be used to place Z-folds and letter-folds in a sheet. Additionally, by locating the outlet at the second end of the fold position controlling chamber so that folded sheets can be outputted from the sheet folding apparatus by passing them through the fold position controlling chamber without being blocked by any fold plate stops, a particularly compact design can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein:
FIG. 1A is a side view of a buckle folder which uses a single fold chamber and a pair of fold rollers to place a fold in a sheet;
FIG. 1B is a side view of a knife folder which uses a knife to force a sheet between a pair of fold producing rollers;
FIG. 2A is an isometric view of a sheet folded into a letter-fold;
FIG. 2B is an isometric view of a stack of sheets wherein the upper sheet is folded into a Z-fold;
FIG. 3 is a side view of a prior art folding apparatus for placing Z-folds in a sheet of paper;
FIG. 4 is a side view of a first embodiment of the present invention and illustrates three positions of a control gate used with this embodiment;
FIGS. 5A-H illustrate the movement of a sheet through the embodiment of FIG. 4 to place a Z-fold in the sheet;
FIGS. 6A-E illustrate the movement of a sheet through the embodiment of FIG. 4 to place a half-fold in the sheet;
FIG. 7 is a side view of a dual-solenoid mechanism for moving the control gate of the embodiment of FIG. 4 through its three positions;
FIGS. 8A-C are side views of the embodiment of FIG. 4 and illustrate how the mechanism of FIG. 7 moves the control gate through its three positions;
FIG. 9 is a side view of a second embodiment of the present invention;
FIGS. 10A-B illustrate the way in which a sheet will be folded when passed through the embodiment of FIG. 9 and a mirror image of the embodiment of FIG. 9, respectively;
FIGS. 11A-H illustrate the movement of a sheet through the embodiment of FIG. 9 to place a Z-fold in the sheet;
FIG. 112 is a side view of a third embodiment of the present invention;
FIGS. 13A-B illustrate how a sheet is folded when passed through the embodiment of FIG. 12 and a mirror image of the FIG. 12 embodiment, respectively;
FIGS. 14A-H illustrate the movement of a sheet through the embodiment of FIG. 12 to place a Z-fold in the sheet;
FIG. 15 is a side view of a fourth embodiment of the present invention;
FIGS. 16A-B illustrate how a sheet is folded when passed through the embodiment of FIG. 15 and a mirror image of the FIG. 15 embodiment, respectively;
FIGS. 17A-H illustrate the movement of a sheet through the embodiment of FIG. 15 to place a Z-fold in the sheet; and
FIG. 18 is a timing diagram illustrating the actuation of the control gate and exit gate of the embodiment of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 4 is a side view of a first embodiment of a sheet folding apparatus 50 according to the present invention. Sheet folding apparatus 50 includes an inlet 52 which receives a sheet being fed in feed direction F. A sheet can be fed to folding apparatus 50 from, for example, a copier or a printer. The sheet enters first passage 55 and contacts a moving gate buckle registration system 56 which deskews the sheets as they enter the folder. A switch 54 is used to time the actuation of gate 56. When stop gate 56 is moved out of first passage 55, the sheet will be engaged between rollers 58 and 60 and deflected into fold position controlling chamber 64 by control gate 62. Control gate 62 can be moved in a controlled manner between positions A, B and C as described below. Initially, control gate 62 is in position A so that the sheet is directed into fold position controlling chamber 64. When placing Z-folds in sheets, a fold plate stop 68 is positioned in chamber 64 to block the passage of the sheet therethrough. Once the lead edge of the sheet is blocked by fold plate stop 68 and control gate 62 is moved to position B, a buckle will form in the sheet and eventually be captured in the nip 72 between first and second fold producing rollers 58,70 which then place a fold in the sheet as well as withdraw the sheet from the fold position controlling chamber 64. A sensor 66 is provided in fold position controlling chamber 64 and detects the movement of the sheet into fold position controlling chamber 64 to signal a controller, to be described below, that control gate 62 should be moved to position B. Once folded and withdrawn from fold position controlling chamber 64, the sheet is conveyed along a recirculation passage which extends around the periphery of one of the fold producing rollers 70. The recirculation passage is defined by a plurality of plates 74 and also includes one or more follower rollers 76 that contact fold producing roller 70 to convey the sheet around roller 70. After being conveyed around roller 70 once, the sheet is directed back into fold position controlling chamber 64 by contacting control gate 62 while in position B. After the sheet is sensed by sensor 66, control gate 62 is moved entirely out of the sheet conveying passages to position C. A second buckle is then formed in the sheet, which buckle is captured in nip 72 formed between first and second fold producing rollers 58,70 to place a second fold in the sheet while withdrawing it from fold position controlling chamber 64. Control gate 62 is then returned to position A and the sheet, after being conveyed around fold producing roller 70, is directed back into the fold position controlling chamber 64.
Once the desired number of folds (usually two) are formed in the sheet, fold plate stop 68 is moved out of chamber 64 to open this chamber and allow the sheet to exit folding apparatus 50. An extension 78 can be added to fold position controlling chamber 64 and an additional fold plate stop 80 can be added so that a sheet can optionally be folded in half by sheet folding apparatus 50. Obviously, when sheets exit sheet folding apparatus 50 which includes the half fold option, both fold plate stops 68 and 80 must be moved out of chamber 64 and extension 78.
FIGS. 5A-H illustrate the movement of a sheet through sheet folding apparatus 50 to place a Z-fold in the sheet. These figures also illustrate the location of control gate 62 and fold plate stop 68 during the folding process. FIGS. 6A-E illustrate the movement of a sheet through sheet folding apparatus 50 utilizing extension 78 and second fold plate stop 80 to form a half-fold in a sheet. As can be seen from FIG. 5A-H and 6A-E, the sheet enters fold position controlling chamber 64 from a first direction when entering from the inlet and from a second direction, different from the first direction, when entering from the recirculation passage. Control gate 62 is required in order to ensure that the sheet properly enters chamber 64 regardless of its direction of entry.
The embodiment illustrated in FIG. 4 can also be used to form letter-folds in sheets of paper by providing an additional fold plate stop 69. The position of this stop will depend on the size of sheet to be folded. As a sheet is initially directed into fold position controlling chamber 64 from first passage 55, stop 68 would be moved out of chamber 64 and stop 69 would be moved into and thus block passage of the sheet through chamber 64. A first fold would then be formed in the sheet as described above except that this fold would be produced closer to the trailing end of the sheet than when a Z-fold is produced. After being directed around the recirculation passage, the sheet is directed back into chamber 64 except an appropriately positioned fold plate stop is now located in chamber 64 to block passage of the sheet therethrough. A second fold is then placed in the sheet as described above, except, due to the use of fold plate stop 69 in forming the first fold, the resulting twice-folded sheet will be in the form of a letter-fold.
Instead of exiting from fold position controlling chamber 64, an outlet can be provided along the recirculation passage. A movable outlet deflector gate would be located between the outlet and the recirculation passage and would be selectively movable into the recirculation passage to deflect the folded sheet to the outlet. The provision of an outlet in the recirculation passage will be described in more detail below with reference to other embodiments. It is also understood that a sheet can be passed through folding device 50 without being folded simply by moving all of the fold plate stops, 68,69 and 80 out of chamber 64.
FIGS. 7 and 8A-C illustrate the mechanism for moving the three position control gate 62 which is used to guide sheets into the fold position controlling chamber 64 from two different directions. The mechanism includes a first linkage 82 which is pivotally attached at first end 81 to control gate 62 at pivot point 86 and a second linkage 96 which is also pivotally attached to control gate 62 at one end and pivotally attached to a frame member at another end. Linkage 82 is pivotally mounted in apparatus 50 at pivot point 84. The linkage 82 is attached to drive solenoid 88 through link 90 at a second end 83 thereof. A small solenoid 92 includes a pin 94 which acts as a stop for linkage 82, by contacting surface 97 thereof, to provide the three positions A, B and C of control gate 62. Pin 94 is attached to one end of a pivot arm 93 which is attached to an actuator arm of solenoid 92 and is pivotally mounted to a supporting surface 95 at an end thereof opposite from the pin 94. Pivot arm 93 thus supports the weight of linkage 82 and allows the full life expectancy to be realized from solenoid 92 as opposed to an arrangement where the actuator arm of solenoid 92 directly engages surface 97 of linkage 82 which results in solenoid 92 supporting the weight of linkage 82. When solenoid 88 is activated, linkage 82 is pivoted about pivot point 84 to move control gate 62 to position B as shown in FIG. 8B. When drive solenoid 88 is deactivated, and if small solenoid 92 is activated to move pin 94 out of the path of linkage 82, linkage 82 will pivot about pivot point 84 to move control gate 62 to position C as shown in FIG. 8C. However, if solenoid 92 is not activated and pin 94 extends into the path of linkage 82, linkage 82 will move until blocked by pin 94 and place control gate 62 at its central position A as illustrated in FIG. 8A.
FIG. 9 is a side view of a second embodiment of a sheet folding apparatus 100 according to the present invention. Sheet folding apparatus 100 includes an inlet 152 which receives a sheet being fed in the feed direction S. The embodiment illustrated in FIG. 9 is similar to the FIG. 4 embodiment except that the sheet is fed to the fold position controlling chamber 164 from the same direction when moved from the inlet 152 and from the recirculation passage provided around fold producing roller 170. An advantage of this embodiment is that no control gate is required since the sheet always enters fold position controlling chamber 164 from the same direction. A plurality of fold plate stops 168a-d and 180 are provided in fold position controlling chamber 164 to locate a fold at a variety of locations on sheets having a variety of sizes.
In order to form a Z-fold the second embodiment operates as follows. A sheet enters inlet 152 and is conveyed through first passage 155 to rollers 160 and 170. First passage 155 can include a moving gate buckle registration system and a stop gate as in the first embodiment. The sheet is then conveyed by rollers 160 and 170 into the fold position controlling chamber 164 until it contacts, for example, fold plate stop 180. A buckle then forms in the sheet which is captured in the nip formed between first and second fold producing rollers 158, 170. Fold producing rollers 158, 170 place a first fold in the sheet while withdrawing the sheet from fold position controlling chamber 164. The sheet then passes through the recirculation passage which is defined by plate(s) 174 and follower roller 176 and is reinserted into fold position controlling chamber 164. A second fold is then placed in the sheet as described above. The sheet exits folding apparatus 100 one of two ways. If the outlet passage is located on the end of fold position controlling chamber 164 opposite from the end adjacent fold producing rollers 158,170, the sheet is conveyed entirely around the recirculation passage and back into the fold position controlling chamber 164. However, after placing the desired number of folds in the sheet, all of the fold plate stops 168a-d and 180 are moved to the open position so that the folded sheet passes entirely through chamber 164 to the outlet. Alternatively, an outlet can be provided which is in communication with the recirculation passage. For example, a movable outlet deflector gate 190 can be provided which, when moved into the recirculation passage, deflects the sheet out of the recirculation passage to output rollers 192. Output rollers 192 then conveys the sheet through outlet passage 194 to, for example, an output tray.
FIG. 10A illustrates the input and output orientations of a sheet which is Z-folded by the apparatus according to FIG. 9. FIG. 10B illustrates the input and output orientations of a sheet folded by an apparatus which is constructed as a mirror image of the FIG. 9 embodiment. Thus, the output shown in FIG. 10A would result when the device of the present invention is used with a printer or copier which outputs documents from its left side, whereas the FIG. 10B output would result with a right side outputting printer or copier. FIG. 11A-H illustrates the movement of a sheet S through the embodiment of FIG. 9 to place a Z-fold in the sheet.
FIG. 12 is a side view of a third embodiment of a sheet folding apparatus 200 according to the present invention. The embodiment of FIG. 12 operates in a manner similar to that of the FIG. 9 embodiment, except that it is more compact and capable of inputting and outputting sheets from different directions than the FIG. 9 embodiment. A sheet enters input 252 and, after passing through first passage 255 is directed into fold position controlling chamber 264 by rollers 260,270. The sheet is stopped by, for example, fold plate stop 280 and a buckle is formed and captured in the nip defined between first and second fold producing rollers 258,270. The sheet is folded and withdrawn from chamber 264 by fold producing rollers 258,270 and conveyed through the recirculation passage defined around the outer periphery of fold producing roller 270 with the assistance of follower roller 276. The once-folded sheet is inserted into chamber 264 from the recirculation passage in the same direction as when inserted from first passage 255 and is stopped by, for example, fold plate stop 268. The sheet is folded a second time as described above and exits folding apparatus 200 either through outlet passage 294 (through the actuation of a movable outlet deflector gate described above) or through the end of fold position controlling chamber 264 opposite from the end adjacent fold producing rollers 258,270. FIGS. 13A and 13B are similar to FIGS. 10A and 10B and illustrate the input and output orientations of a sheet which is conveyed through the FIG. 12 device and a mirror image thereof, respectively. FIGS. 14A-H illustrate the positions of a sheet as it is conveyed through folding apparatus 200 to place a Z-fold therein.
FIG. 15 is a side view of a fourth embodiment of a sheet folding apparatus 300 according to the present invention. An advantage of the FIG. 15 embodiment is that a sheet can be passed therethrough without being folded quickly and easily by providing outlet 394 and movable outlet deflector gate 390. After entering inlet 352, a sheet passes through first passage 355 and between rollers 360 and 370. If the sheet is not to be folded, movable outlet deflector gate 390 is moved into the passage (which is the recirculation passage) around roller 370 to deflect the sheet into outlet passage 394. If the sheet is to be folded, deflector gate 390 is moved to block outlet passage 394 and permit the movement of the sheet around the outer periphery of roller 370 and between rollers 370,376 to be inserted into fold position controlling chamber 364. The sheet is stopped by fold plate stop 380 and a buckle is formed therein and captured by the nip defined between first and second fold producing rollers 358,370. The sheet is folded and withdrawn from fold position controlling chamber 364 as described above. After recirculating around roller 370, the sheet is reinserted into chamber 364 and is stopped by fold plate stop 368. A second fold is placed in the sheet and it is then outputted from folding apparatus 300 through either outlet passage 394 or the end of fold position controlling chamber 364 which is opposite from the end adjacent the first and second fold producing rollers 358,370. The sheet exits along one of the paths indicated by arrows E. As described above, the fourth embodiment can include an additional fold plate stop for placing half-folds in sheets. It is understood that a sheet can be outputted through either of the outlets at any time (i.e., before or after being once or twice folded). FIGS. 16A and 16B illustrate input and output orientations of a sheet which is passed through the FIG. 15 embodiment or a mirror image thereof to produce a Z-fold therein. FIGS. 17A-H illustrate the positions of a sheet as it is passed through the FIG. 15 embodiment to place a Z-fold therein.
EXAMPLE
A sheet folding apparatus according to the embodiment illustrated in FIG. 4 (that is, the embodiment including the three position control gate 62) was built and controlled as described below. During a Z-folding cycle, the three-position gate 62 must undergo three movements and the fold/exit gate (e.g., gate 68 if it is the only gate in chamber 64) must be actuated once. The timing for these movements was studied and optimized to give the maximum possible latitude. Solenoid response times were measured and folder operation over a large tolerance of control gate spring forces was verified. Although most testing was done with the folder operating at a paper speed of 500 mm/second, the discussion below describes the necessary changes required to run at any paper velocity. FIG. 18 illustrates the nominal timing parameters used when the Z-folder is run at 500 mm/s. The location of a 17 inch sheet within the folder is shown during various stages of the cycle for reference. The folding apparatus was constructed according to the following parameters: the distance from sensor 66 to fold/exit gate 68 was 20 mm; the diameter of first fold producing roller 58 was 35 mm; the diameter of second fold producing roller 70 was 89.2 mm; and the distance along the recirculation path between rollers 58 and 76 was 200 mm. Fold producing roller 58 was made from EPDM (ethylene-propylene-diene random copolymer) having a Shore A hardness of 63 and was spring loaded against roller 70 with a total force of 27 ± 4.5 lbs. although the force can be within the range between about 20 and 44 lbs. Fold producing roller 70 had a surface made from MCPU (Micro Cellular Polyurethane or Mearthane) having a Shore A hardness of 46. The follower rollers 60 and 76 were standard Delrin rollers. The three movements of the control gate 62, and the actuation of the fold gate stop 68 are referenced from four transitions of the fold plate sensor 66 and have been denoted as T4, T5, T6, and T7. These four timing parameters will be discussed individually.
T4
This time determines when the three-position gate 62 moves from its center position A, where it guides the leading edge of the sheet into the fold position controlling chamber 64, to its upper position B. When the gate 62 is in upper position B, the sheet has room to extend into the buckle chamber and be drawn into the fold nip 72. If the gate is actuated too late, the paper may begin to buckle within the chamber 64, potentially causing a jam or paper damage. The time required for the paper to move the 20 mm distance from the sensor 66 to the fold plate stop 68 is simply,
t=20 mm/V.sub.paper.
For a paper velocity of 500 mm/s, this yields 40 ms. The nominal gate actuation time (i.e., stroke time from center to upper position) was determined to be 40 ms, however a tolerance of plus or minus 20 ms was assumed to insure reliable operation in maximum latitude. The acceptable range of actuation times was determined empirically. T4 was varied from 12 to 70 ms with no degradation in folder performance. From this, a nominal T4 of 30 ms was chosen. A general equation for determining the nominal value of T4 at different paper speeds (assuming a gate actuation time of less than 60 ms) can then be expressed as:
T.sub.4 =(D.sub.sensor-foldgate(mm) /V.sub.paper(mm/s))-0.01 sec.
This time determines when the drive solenoid 88 for the three-position control gate 62 is released. This occurs just prior to the formation of the second fold. In order to minimize the size of the large fold roll 70, and the folder cycle time, a paper path length was chosen that results in the trail edge of a folded sheet leaving the area below control gate 62 just before its lead edge contacts the fold plate stop 68. The geometry is utilize to time the downward motion of control gate 62 by releasing the gate onto the trail edge of the sheet as it exits fold position control chamber 64. The gate 62 then drops when the trail edge passes the gate. If it is not desired to contact the trail edge of the sheet with control gate 62, it would be a simple design change to increase the large fold roll 70 diameter slightly and to electronically release the gate at the appropriate time.
By using the trail edge of the sheet to trigger the motion of the control gate 62 (i.e., when sensor 66 detects the trailing edge of the sheet exiting fold position controlling chamber 64), a very consistent release time is seen. This makes the release time of the solenoid 88 less critical. As shown in FIG. 18, the solenoid 88 is electronically released 480 ms after the sheet leaves the fold chamber sensor 66. The gate 62 drops against the trail edge of the sheet 30 ms later and remains there for 85 ms before the trail edge releases gate 62. A value of T5 for use at other paper speeds can be calculated from:
T.sub.5 =(240/V.sub.Paper(mm/s)) sec.
The only disadvantage of using the above system is that the gate drop time is slightly different for 11 × 17 inch paper and A3 (16.54 inches long) sheets. This results in the lead edge of A3 paper being 5.8 mm farther from the fold plate stop 68 than the lead edge of 17 inch paper when the gate 62 drops. Testing showed this small difference to have no effect on folder performance.
More important than the electrical release time of the solenoid 88 is the time required for the gate 62 to drop once it is released. The above-described gate system ad a rotational inertia I of approximately 0.0017 kg-n2 and the return spring of solenoid 88 provided a total return torque T (including the weight of the gate) of 0.3N-n. This yields a theoretical return stroke time of: ##EQU1## wherein θ is the angle through which the control gate swings from position B to position C. The actual return stroke time was measured to be 70 ms as shown in FIG. 18. Empirical studies yielded the following guidelines for maximum allowable gate release/stroke times:
Gate motion must begin within a time of (8/V paper (mm/s)) sec. after the leading edge of the sheet contacts the fold plate stop 68. (This is automatically ensured when using the trailing edge to release the gate as explained above.)
Once motion begins, the total stroke time should be less than (50/V paper (mm/s)) sec. to ensure the control gate 62 clears the buckle chamber. (At a paper velocity of 500 mm/s, this yields a maximum allowable stroke time of 100 ms.)
T6
This timing constant determines when the three-position control gate 62 is brought from its lowest position C (where it resided during the second fold) to its uppermost position B (where it acts to guide the sheet back into fold chamber 64). This time must be calculated so as to ensure that the trailing edge of the "Z" folded sheet has cleared the fold chamber before the gate 62 reaches its upper position. If actuated too soon, the gate can damage the trailing edge of the sheet. As shown below, the time elapsed between the moment the sheet unblocks the fold chamber sensor 66 to the time the trailing edge clears the path of the gate 62 is: ##EQU2## For the present system this yields: t clear =[88 mm-5 mm+ (17"/4) (25.4 mm/in)]/500 mm/s=0.382 sec.
From the above analysis it is seen that gate 62 must not cross the paper path less than t clear seconds after the sheet clears the fold chamber sensor 66. Note that 17" paper will be a worse case condition since A3 is shorter and will clear the control gate 62 sooner. The solenoid/gate actuation time (from lower to upper gate position) was measured to be 100 ms, and the gate was observed to cross the paper path after a period of 90 ms. If a tolerance on this value of ±30 ms is assumed, then the earliest solenoid actuation time for this system is: ##EQU3## From the time the trail edge of a "Z" folded 17" sheet leaves the fold chamber sensor 66 to the time its lead edge reenters the fold chamber 64, the sheet must travel a distance of approximately 230 mm. At 500 mm/s, this distance will be traveled in a time of 460 ms. Taking the worst case gate actuation time to be 90+30=120 ms, then we find:
T6.sub.max =460 ms-120 ms=340 ms.
The theoretical T6 min calculated above was verified empirically by reducing T6 until trail edge damage occurred. With a nominal 90 ms gate actuation time, T6 was reduced to 280 ms before damage was seen. Empirical testing to verify T6 max showed there to be considerably more latitude than the theoretical calculations indicated. T6 was increased up to 560 ms before failure occurred, indicating that the sheet was able to reenter the fold chamber without the assistance of the 3-position gate. However, since this test was not performed using stress case up-curl, it is still recommended that the theoretical maximum for T6 be used. A general equation for the recommended nominal value of T6 (assuming a gate actuation time of 90 + 30 ms) is then:
T6=(230 mm/V.sub.paper(mm/s))-t.sub.gate actuation time(max)
Lastly, it should be pointed out that T6 also determines when the fold chamber exit gate is raised and when the fold chamber stop is released. The fold gate stop should not be released before the gate is actuated (to minimize drag on the gate), but other than that these actions can tolerate large timing variations with no effect on folder performance.
T7
This time determines when the exit gate can be dropped back into position in preparation for the next sheet to enter the fold chamber. After the trail edge of a completed "Z" folded sheet leaves the fold chamber sensor 66, it will clear the fold chamber area in a time of t=d fold chamber-sensor/V paper . Adding in a small safety margin yields a general equation for T7 of:
T7=(d.sub.fold chamber-sensor/ V.sub.paper)+0.01 sec.
Half Folding Requirements:
For half folding, the three position control gate 62 only has to move twice (between the center and uppermost positions). The only critical movement is the first movement and will occur at a time equal to T4 (from "Z" folding mode) plus the time it takes the sheet to travel from the "Z" fold plate stop 68 to the half fold plate stop 80=(d "Z"-half fold plate stops /V paper ).
Thus, a device which is capable of place Z-folds, letter-folds and half folds in a sheet which requires only a single fold position controlling chamber and one pair of fold producing rollers is provided. The folder of the present invention requires less space and is less costly than previous Z-folders. The present invention has a small number of parts and is less susceptible to paper jams. Since all folds are produced in the same nip, they will be consistent with one another.
The present invention can be located downstream of existing printer or copier systems and can be incorporated into existing systems where documents are folded and placed into envelopes which are then sealed and outputted "ready-to-mail".
While the present invention is described with reference to Z-folders, this particular embodiment is intended to be illustrative, not limiting. For example, the present invention can also be used to place half-folds and letter-type folds in sheets. It is also understood that recirculation of sheets could also be accomplished using baffles and drive rollers which are separate from the fold rollers. Various modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
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A sheet folding apparatus is disclosed which includes an inlet for receiving a sheet material from outside of the sheet folding apparatus, an outlet for discharging the sheet material to outside of the sheet folding apparatus, and a folding mechanism within the apparatus for placing one or more folds in the sheet material. The folding mechanism includes a fold position controlling chamber having first and second ends and including at least one fold plate stop spaced from the first end for blocking the fold position controlling chamber, first and second fold producing rollers contacting each other at peripheral surfaces thereof and located adjacent the first end of the fold position controlling chamber for withdrawing a sheet from the fold position controlling chamber and placing a fold therein and a recirculation passage extending around the periphery of one of the first and second fold producing rollers so that a sheet can be conveyed around the outer periphery thereof and be inserted back into the fold position controlling chamber after being withdrawn from the fold position controlling chamber by the first and second fold producing rollers. The once-folded sheet can then be directed to the outlet or back through the first and second fold producing rollers to place a second fold therein. This structure permits one or more folds to be placed in sheet material while requiring only a single fold position controlling chamber and one pair of fold producing rollers.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which claims benefit under 35 USC §119(e) of and priority to U.S. Provisional Application Ser. No. 61/847,895 filed 18 Jul. 2013, entitled “PRE-POSITIONED CAPPING DEVICE FOR SOURCE CONTROL WITH INDEPENDENT MANAGEMENT SYSTEM,” which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] Embodiments of the invention relate generally to systems and methods for containing fluids discharged from a subsea well or at the surface.
BACKGROUND OF THE INVENTION
[0003] In offshore floating drilling operations, a blowout preventer (BOP) can be installed on a wellhead at the sea floor and a lower marine riser package (LMRP) mounted to the BOP. In addition, a drilling riser extends from a flex joint at the upper end of LMRP to a drilling vessel or rig at the sea surface. A drill string is then suspended from the rig through the drilling riser, LMRP, and the BOP into the wellbore. A choke line and a kill line also suspend from the rig and couple to the BOP, usually as part of the drilling riser assembly.
[0004] Another type of offshore drilling unit is a jack-up unit, which may include a BOP at the surface located on the unit. The jack-up unit can drill with a subsea wellhead on the seabed, a high pressure riser up to the jack-up unit, and the surface BOP connected to the high pressure riser. Offshore drilling can also be done from an offshore platform, a piled structure, a gravity based structure, or other permanent type structure. These drilling operations may use a surface BOP.
[0005] During drilling operations, drilling fluid, or mud, is delivered through the drill string and returned up an annulus between the drill string and casing that lines the well bore. In the event of a rapid influx of formation fluid into the annulus, commonly known as a “kick,” the BOP may be actuated to seal the annulus and control the well. In particular, BOP's include closure members capable of sealing and closing the well in order to prevent release of high-pressure gas or liquids from the well. Thus, the BOP's are used as safety devices to close, isolate, and seal the wellbore. Heavier drilling mud may be delivered through the drill string, forcing fluid from the annulus through the choke line or kill line to protect the well equipment disposed above the BOP from the high pressures associated with the formation fluid. Assuming the structural integrity of the well has not been compromised, drilling operations may resume. However, if drilling operations cannot be resumed, cement or heavier drilling mud is delivered into the well bore to kill the well.
[0006] In the event the BOP fails to actuate, or insufficiently actuates, in response to a surge of formation fluid pressure in the annulus, a blowout may occur. Containing and capping the blowout may present challenges since the wellhead may be hundreds or thousands of feet below the sea surface and, with surface BOP's, the flow presents a great danger of fire or explosion. Personnel are forced to evacuate the drilling unit if a well blows out as it is very dangerous.
[0007] Accordingly, there remains a need in the art for systems and methods to cap a well quickly to stop flow. Such systems and methods would be particularly well-received if they offered the potential to cap a well discharging hydrocarbon fluids almost immediately. This would reduce potential environmental damage and danger to personnel and the drilling unit.
[0008] Well capping subsea is an involved process. The floating drilling unit may have been damaged, even sunk, on location. Debris from the drilling unit has to be cleared from the wellsite. Preparations involve injecting dispersants subsea into the blowout to disperse oil and gas in the water column. This dispersion then allows vessels with debris removal equipment to clear the area around the BOP. Once this area is cleared, another vessel can install the capping stack and shut in the well. This process can take 10 to 21 days with uncontrolled well flow to the environment. Complexness of this operation may require five or more large vessels.
[0009] Well capping with a surface BOP offshore, jack-up or platform takes a similar time period. During the capping operation the danger of fire and explosion is always present. If fire or explosion does occur, the platform or jack-up can be a complete loss. If the platform has multiple wells, all the wells can blowout. To ensure fire or explosion does not occur, the drilling unit must be deluged with water from several vessels at a high rate. Once deemed safe, personnel inspect the surface BOP and determine how the well can be capped. Debris is cleared by personnel, and BOP equipment is examined. During this period, the deluge from vessels continues and the well flows to the environment. A plan is determined, and the well is capped.
SUMMARY OF THE INVENTION
[0010] In an embodiment, a staged pressure control system attached to a wellhead of a well includes a blowout preventer stack having a first pressure rating. A pre-positioned capping device includes a blind shear ram disposed between the wellhead and the blowout preventer stack to close the well. A second pressure rating of the capping device exceeds the first pressure rating of the blowout preventer stack.
[0011] For another embodiment, a method of controlling a well includes disposing a pre-positioned capping device between a wellhead of the well and a blowout preventer stack having a first pressure rating. The method further includes drilling the well through the capping device and blowout preventer stack and operating the blowout preventer stack to control well events up to a pressure limit. In addition, the method includes controlling a blind shear ram of the pre-positioned capping device having a second pressure rating higher than the first pressure rating in order to close the well if the well event is greater than the pressure limit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
[0013] FIG. 1 is a schematic diagram illustrating a jack-up drilling rig unit in accordance with an embodiment of the present invention.
[0014] FIG. 2 is a schematic diagram illustrating a pre-positioned capping device attached to a wellhead in accordance with an embodiment of the present invention.
[0015] FIG. 3 is a schematic diagram illustrating control of the pre-positioned capping device in accordance with an embodiment of the present invention.
[0016] FIG. 4 is a schematic diagram illustrating use of a pre-positioned capping device with a blowout preventer stack having a lower pressure rating than the capping device in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not as a limitation of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations that come within the scope of the appended claims and their equivalents.
[0018] By way of explanation and not by way of limitation, the following description focuses on subsea pre-positioned capping device (PCD) used with a jack-up drilling unit. However, it is to be clearly understood that the principles of the present invention are not limited to environments as described herein. Thus, the use of the PCD on a jack-up drilling unit is described herein as merely an example of the wide variety of uses for the principles of the present invention. The PCD can be used with a subsea BOP or any surface BOP with location being subsea, on a lower level below the BOP, or positioned immediately below the BOP.
[0019] FIG. 1 illustrates a jack-up drilling rig unit 10 depicted with a jack-up rig 100 resting on the sea-bed 20 . The jack-up rig 100 is a type of mobile platform including a buoyant hull 160 fitted with a number of movable legs 140 , capable of raising the hull 160 over the surface of the sea. The buoyant hull 160 enables transportation of the unit 10 and all attached machinery to a desired location. Once on location, the hull 160 raises to the required elevation above the sea-bed 20 surface on its legs 140 supported by the sea-bed 20 .
[0020] The legs 140 of such units may be designed to penetrate the sea-bed 20 , may be fitted with enlarged sections or footings, or may be attached to a bottom mat. Footings or spudcans 180 spread the load so the rig 100 does not sink into the sea-bed 20 . The base of each leg 140 is fitted with a spudcan 180 , which may include a plate or dish designed to spread the load and prevent over penetration of the leg 140 into the sea-bed 20 . The spudcans 180 may be circular, square or polygonal.
[0021] A high pressure riser 220 leads to the wellhead 200 in the sea-bed 20 . The high pressure riser 220 may be a thick walled, high strength riser and can contain full well pressure. A surface blowout preventer (BOP) stack 240 is located on the jack-up rig 100 . The PCD 300 is pre-installed on the wellhead 200 .
[0022] The PCD 300 functions as an independent safety and containment device for well leakage and/or blowout. The PCD 300 is installed on the well when the BOP stack 240 is installed and is a safety device to be used if the drilling unit's BOP stack 240 fails to control a well blowout. When necessary, the PCD 300 is activated immediately to regain control of the well leak or blowout providing a secondary level of environmental and personnel protection. The PCD 300 can additionally function to secure the well by closure of the PCD 300 if the rig must be moved.
[0023] FIG. 2 shows the PCD 300 designed for attachment onto substantially any wellbore worldwide and for functioning in subsea and surface operations. The PCD 300 forms a capping stack, which may include a first blind shear ram 301 , a second blind shear ram 302 , a power source 307 for closing the rams 301 , 302 and that is independent from the rig 100 and an independent control system 303 . The power source 307 (e.g., pressurized tanks with hydraulic fluid) of the PCD 300 provides stored power to the control system 303 and as otherwise necessary for actuation of the PCD 300 without relying on power from the rig 100 . Since the power source 307 may form an integral component of the PCD 300 and be disposed remote from the rig 100 , collocation of the power source 307 with the blind shear rams 301 , 302 enables operability without relying on hydraulic pressure supplied from the rig 100 .
[0024] The blind shear rams 301 , 302 (also known as shear seal rams, or sealing shear rams) seal the wellbore, even when the bore is occupied by a drill string, by cutting through the drill string as the rams 301 , 302 close off the well. The upper portion of the severed drill string is freed from the ram 301 , 302 , while the lower portion may be crimped and the “fish tail” captured to hang the drill string. For some embodiments, the independent control system 303 for the PCD 300 may not actuate the rams 301 , 302 during normal drilling or kick occurrences handled by the BOP stack 240 but rather only upon the independent control system 303 being operated for loss of control for which the BOP stack 240 does not or cannot regain control.
[0025] The PCD 300 may further include at least one pressure and/or temperature transducer below each ram 301 , 302 capable of analogue local display. The PCD 300 may have a number of outlets 304 . Each outlet may be provided with two hydraulically controlled gate valves. Two of the outlets may be equipped with manually controlled chokes to perform soft shut-in of the second blind shear ram 302 . The capping stack may also include an inlet 305 to inject glycol or methanol to mitigate hydrate formation.
[0026] As described in further detail with respect to FIG. 3 , the independent control system 303 activates the PCD 300 independent from activation of the BOP stack 240 and can be operated by the drilling rig unit 10 or from a vessel or other installation remote from the drilling rig unit 10 . For some embodiments, the control system 303 includes a self-contained electrical supply, such as a battery, for any functions of the control system 303 described herein and utilizing current independent of the drilling rig unit 10 . In some embodiments, the independent control system 303 may form part of a digital acoustic control system. The digital acoustic control system may utilize low frequency sound sent to, or received from, the control system 303 on the PCD 300 .
[0027] FIG. 3 depicts two digital acoustic control systems. The digital acoustic control system on the drilling rig unit 10 includes a rig transducer 315 disposed in the water and coupled to a rig user interface station 320 , which may be operated by the drilling crew or the operator supervisor on the drilling rig unit 10 . The digital acoustic control system on a vessel near the drilling location includes an auxiliary transducer 340 coupled to an auxiliary user interface station 345 , which may be operated by a well control representative. As used herein, an independent management system refers to the auxiliary user interface station 345 with the well control representative not being managed by the drilling crew operating the rig user interface station 320 . For some embodiments, the auxiliary user interface station 345 functions concurrent with the rig user interface station 320 for possible actuation of the PCD 300 if needed.
[0028] The PCD 300 having this independent management system ensures that decisions are made in a timely manner to prevent a major blowout and harm to personnel. Personnel directly involved in the well blowout on the installation, and which perhaps caused it, may not manage the PCD 300 . Independent systems from the drilling rig unit 10 mean that in the event of a large fire/explosion on the drilling rig unit 10 the PCD 300 can still be activated to protect personnel and the environment. As previously mentioned, the PCD 300 may be implemented in numerous cases, including: (1) failure of the well control system on the drilling rig unit 10 ; (2) management system failure on the drilling rig unit 10 ; or (3) fire or explosion on the drilling rig unit 10 that prevents operation or continued operation, i.e., loss of hydraulic pressure on some function, of other well control systems, such as the BOP stack 240 .
[0029] In operation, signals from the rig transducer 315 or the auxiliary transducer 340 to a PCD transducer 310 or a remote transducer 335 provide command signals to the control system 303 for functioning of the PCD 300 . Both the PCD transducer 310 and the remote transducer 335 connect to the control system 303 . The remote transducer 335 may connect to the PCD 300 by a cable 325 of sufficient length (e.g., 150 meters) to enable placement of the remote transducer 335 away from the PCD transducer 310 proximate the PCD 300 . The remote transducer 335 thus may facilitate communicating with PCD 300 should access to the drilling rig unit 10 be restricted. Acoustic data transmission may also be sent from the PCD 300 to the surface via the transducers 310 , 315 , 335 , 340 to monitor the system status and wellbore conditions (e.g., pressure and/or temperature measured by the transducers of the PCD 300 ).
[0030] While the digital acoustic control system functions as the primary PCD control system, a secondary interface may also be utilized. In an embodiment, a remotely operated vehicle (ROV) may be utilized as a secondary PCD control system with the ROV providing physical input direct to the PCD 300 through an ROV control panel 306 . The ROV control panel 306 may send a signal to the control system 303 of the PCD 300 that operates valves sending hydraulic pressure from the power source 307 to operate the blind shear rams 301 , 302 .
[0031] PCD systems on the surface have independent controls also. Examples of such independent controls include wireless controls or shielded fiber optics, cable, or piping. Regardless of signal interface techniques employed, the independent controls enable operation of the PCD systems independent from BOP control systems.
[0032] In some embodiments, the PCD facilitates capping a well almost immediately. This quick response time reduces the chance of fire or explosion endangering personnel or even sinking the drilling unit or complete loss of a fixed platform. The blowout oil spill volume is greatly reduced as the flow duration is minutes instead of weeks reducing the potential for environmental damage.
[0033] There are no issues with installing the system since the PCD is preinstalled. A conventional capping stack, which is installed after a blowout, could encounter a situation where debris prevents installation. The PCD also prevents the situation where the drilling unit or platform collapses on a well due to fire and/or explosion. In this case, the blowout could not be capped with a capping stack due to debris or damage to the BOP and/or wellhead.
[0034] The PCD with independent power can be operated even with significant damage to the drilling unit. The drilling unit's BOP might have failed due to loss of power but this would not impact the PCD. The PCD may include redundant blind shear rams in case one ram fails to shear the drill string and seal the well, but one ram may be sufficient if designed to shear and seal on tubulars used in the well.
[0035] FIG. 4 shows a PCD 430 disposed on a wellhead 420 . The PCD 430 may function and operate as described herein with respect to FIGS. 1-3 . In some embodiments, a BOP stack 440 couples to a top of the PCD 430 opposite the wellhead 420 and is pressure rated below a pressure rating of the PCD 430 .
[0036] For example, the BOP stack 440 may be pressure rated for no more than 104 megapascals (MPa), which is sufficient for normal drilling operations where wellbore pressures are controlled with weight of mud used but may not be adequate to contain possible pressures anticipated at some wells should a blowout occur. The PCD 430 may enable safe operation even during a blowout situation by being pressure rated at the maximum anticipated pressure, such as at least 137 MPa. In some embodiments, the PCD 430 provides an at least 25 MPa or at least 50 MPa greater pressure rating than the BOP stack 440 . For some embodiments, actuation of the PCD 430 occurs upon sensing a pressure at the PCD 430 greater than a threshold pressure limit, such as the pressure rating of the BOP stack 440 .
[0037] The PCD 430 thereby enables cost efficient use of commercial ready to use versions of the BOP stack 440 with wells that may experience pressures above existing pressure ratings of the BOP stack 440 . In particular, increasing pressure ratings of the BOP stack 440 increases weight of the BOP stack 440 and requires all associated equipment to handle this extra weight and also be pressure rated the same as the BOP stack 440 . The PCD 430 ensures that equipment above the PCD 430 would only be exposed to normal operating pressures and would be isolated from maximum well pressures since the PCD 430 would be operated and capable of closing the well.
[0038] The pressure rating of the PCD 430 and the BOP stack 440 may utilize industry practices for qualification. For example, the PCD 430 and the BOP stack 440 may withstand one and one-half times (1.5×) the pressure for which rated without having a mechanical failure or leaking In some embodiments, the BOP stack 440 may fail or leak at pressures below those at which the PCD 430 may fail or leak or even below the pressure rating of the PCD 430 .
[0039] In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as an additional embodiment of the present invention.
[0040] Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.
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Systems and methods contain fluids discharged from a subsea well or at the surface by capping the well blowout with a pre-positioned capping device. The capping device includes at least one blind shear ram and is separate from a blowout preventer. The blowout preventer may operate to control well events up to a certain pressure, above which the capping device is employed since the capping device has a higher pressure rating than the blowout preventer.
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BACKGROUND OF THE INVENTION
This invention relates in general to a method and apparatus for measuring surface porosity and, more specifically, to a novel surface-temperature porosimeter.
Materials having selected surface porosities are in use in a variety of applications. In many cases, it is necessary that the surface porosity be carefully maintained within a limited range. Examples of such materials include foam insulation for cryogenic applications, graphite ablative materials, protective coatings, etc. A non-destructive porosity measuring technique would be a very helpful quality control aid in assuring that porosity of insulation coatings, ablative heat shields, etc. on production structures is within the required range.
Prior art porosity techniques generally require removal of samples of the material and testing in complex laboratory apparatus. These techniques are slow and cumbersome and do not permit testing of actual production materials in place.
Thus, there is a continuing need for improved porosity measuring systems.
It is, therefore, an object of this invention to provide a porosimeter overcoming the above-noted problems.
Another object of this invention is to provide a nondestructive method of determining porosity.
A further object of this invention is to provide a method and apparatus for determing the relative density, porosity and pore spectra of materials.
SUMMARY OF THE INVENTION
The above objects, and others, are accomplished in accordance with this invention by a system in which a quantity of a volatile liquid is applied to a surface and allowed to evaporate while the temperature of the surface is continuously measured. This temperature reaches equilibrium at the point necessary to supply the latent heat of vaporization of the liquid. This equilibrium temperature depends on the evaporation rate. The liquid when applied is absorbed by pores in the structure. As the liquid evaporates, the liquid at the surface is replenished by capillaries attributable to open porosity and the volume of retained liquid so that evaporation rate and time and the resulting surface equilibrium temperature are functions of surface porosity.
Since the evaporation rate is determined in part by the temperature of the air surrounding the surface, the porosimeter preferably includes an insulated chamber maintained at a substantially constant temperature around the surface area being tested. Also, it is desirable to include means for preventing vapor buildup which may reduce the evaporation rate of the liquid.
Any suitable liquid may be used in this system. The liquid should be sufficiently volatile to evaporate in a reasonable time at the temperature being maintained in the system, which ordinarily will be near room temperature. The liquid should not dissolve or otherwise degrade the material being tested. Typical liquids useful with many porous materials include low molecular weight alcohols, dichloro methane, carbon tetrachloride, water and mixtures thereof.
The liquid may be applied to the surface in any suitable way. Where small blocks are being tested, the block may be placed in a dish containing a shallow pool of liquid. For larger surfaces, often spraying or feeding a stream of liquid through a metering valve may be preferred.
BRIEF DESCRIPTION OF THE DRAWING
Further details of the invention, and of a preferred embodiment of the invention, will be further understood upon reference to the drawing, wherein:
FIG. 1 shows a schematic diagram illustrating the porosimeter of this invention; and
FIG. 2 shows a curve of temperature plotted against time for the measurement of porosity.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is seen a schematic block diagram illustrating the porosimeter of this invention. The porosity measuring assembly is enclosed within a generally bell-shaped chamber 10 which is placed with the open end in contact with the structure surface 12 to be tested.
The selected volatile liquid is fed from a reservoir 14 through a feeding means 16 to a tube 18 which deposits the liquid on the surface of structure 12 near the center of chamber 10. As mentioned above, any suitable volatile liquid which is compatible with the composition of structure 10 may be used. Preferably, the same quality of liquid is applied when calibrating the system with structures of known porosity and then with test structures of unknown porosity. Where reservoir 14 is calibrated in the manner of a graduate cylinder, feeding means 16 may be a stopcock or similar valve allowing the selected quantity as measured at reservoir 14 to flow by gravity to tube 18. Alternatively, feeding means 16 could be a metering pump which would spray a selected quantity of liquid onto the surface of structure 12. If structure 12 is small in size, the test surface could be immersed in a shallow pool of liquid, then placed in contact with chamber 10. While gravity feed of a measured amount of liquid is preferred for simplicity and accuracy, any other suitable liquid application technique may be used, if desired.
Preferably, a sealing means 20, typically an "O" ring, is placed around the contact ring between chamber 10 and structure 12 to protect against varying air leaks therebetween which might affect the evaporation rate at the nearby liquid test area.
Since the evaporation rate is influenced by the temperature of the air surrounding the surface, it is preferred that chamber 10 be maintained at a substantially constant temperature. This may be accomplished by a water jacket 22 surrounding chamber 10. A liquid, such as water, at a selected temperature, is circulated between water jacket 20 and a heat exchanger 24 by pump 26.
The temperature at the surface of structure 12 is continuously monitored. Typically, a thermocouple 28 may extend through the wall of chamber 10 into contact with the surface of structure 12 at the spot where the volatile liquid is applied. The temperature is recorded by a recorder 30 which provides a plot of temperature against time of the sort illustrated in FIG. 2.
Since the buildup of vapor within chamber 10 as the test liquid evaporates may reduce the evaporation rate, chamber 10 is preferably vented, such as by vents 32. Since the amount of liquid is ordinarily quite small, vapor buildup is not ordinarily a significant problem. However, if desired, air at chamber temperature may be pumped through chamber 10 at a low rate to carry off excess vapor.
The porosimeter schematically illustrated in FIG. 1 can be assembled into a small, portable unit which can be taken wherever desired to measure the porosity of coatings, insulation, etc., on large structures. Once the characteristics of samples of known porosity are measured, the porosity of an unknown porosity sample of the same composition can be quickly determined.
In a typical measuring operation, chamber 10 is placed in contact with the surface of a structure of known or unknown porosity. Heat exchanger 24 and pump 26 are operated to bring the temperature within chamber 10 to a stable selected temperature which ordinarily will be close to the structure temperature under the existing ambient conditions. Temperature recorder 30 is activated and a measured quantity of liquid is applied to the structure surface through tube 18. As shown by curve 31 in FIG. 2, the temperature measured by thermocouple 28 initially drops rapidly from ambient temperature 33 over time span 34, then levels off when the volume of liquid returning to the surface from large pores feeding capillaries within the structure equals that being evaporated. The temperature remains substantially constant for time period 36 until these subsurface reservoirs are exhausted, at which time (as shown at 38) the temperature rises as the liquid in the capillaries is depleted and the surface returns to ambient temperature. The time periods 36 and 38 are shorter for more dense materials and longer for more porous materials. By running a series of tests with samples of a single composition of different porosity, a series of curves similar to that shown in FIG. 2 can be developed. Then, a curve for a sample of the same compoisition but unknown porosity can be comparied to the standard curves to nondestructively determine the porosity of the unknown sample. Comparison of curves for known and unknown porosity may be accomplished by comparing the shape of the curves, the length of time periods 34, 36 and 38, or by integrating the area between curve 31 and ambient temperature 33. Generally, the most accurate results are obtained by comparing the curves produced during time period 38, or by comparing equilibrium temperatures for controlled liquid volumes which penetrate the surface.
Details of several preferred embodiments of the method of this invention will be further described in the following examples. Parts and percentages are by weight unless otherwise stated.
EXAMPLE I
Four blocks of polyurethane foam of the type used for cryogenic tank insulation having densities of 0.422, 0.460, 0.498 and 0.536 g/cm 3 and one having an unknown density are prepared. The first block is placed in contact with a test chamber of the sort shown in FIG. 1 and a heat exchanger circulating water around the chamber is activated to bring the chamber to a uniform 20°C. A chromel-alumel thermocouple is placed in contact with the foam near the center of the chamber and is connected to a single channel strip chart recorder, available from Honeywell, Inc. A reference junction is provided for absolute measurement. About 0.5 ml. of dichloro methane is fed into the chamber and dropped onto the foam surface at the point of thermocouple contact. The recorder traces a a curve of time against temperature similar to that shown in FIG. 2. The other four foam samples are then tested in the same manner. The area between the ambient temperature line and the curve, and the time to return to substantially ambient temperature, are found to decrease with increasing density through the four known samples. The curve for the unknown sample is compared to the four known sample curves. The unknown curve falls between the curves for the 0.422 and 0.460 g/cm 3 curves, indicating that the density of the unknown sample is about 0.440 g/cm 3 .
EXAMPLE II
Two molded graphite blocks having densities of 1.80 and 1.60 g/cm 3 are prepared. A small quantity of ethyl alcohol is placed in a shallow dish and a block is placed in the dish. After about 5 seconds, the block is removed and placed in the test apparatus described in Example I. As the alcohol evaporates, the recorder plots a time/temperature curve similar to that shown in FIG. 2. The test is repeated with the second block, producing a second curve. Then a third block having an unknown density is tested in the same manner. Comparison of the three curves indicates the density of the unknown block to be about 1.72 g/cm 3 . Later density measurements show this density test to be accurate within about ±0.01 g/cm 3 .
EXAMPLE III
Two sheets of polyphenylene oxide foam, available from General Electric under the PPO trademark, are prepared. The sheets have densities of about 0.536 and 0.460 g/cm 3 . An iron-constantan thermocouple connected to a strip chart recorder is placed in contact with each sheet. About 0.1 ml. of methyl chloride is sprayed on each sheet in the area of thermocouple contact. A hemispherical cover maintained at about 68°F is placed over each test area and a stream of air at about 68°F is passed slowly through ducts connected to the cover. Each recorder produces a curve similar to that shown in FIG. 2. The surface temperature drops to about 20°F, then after a stable period returns to ambient temperature. This stable period is much shorter, and thus the evaporation rate more rapid, in the more dense specimen.
EXAMPLE IV
Six standard test blocks of open cell silicon foam of known different densities and one sheet of unknown density are tested using a surface temperature porosimeter of the type illustrated in FIG. 1. The blocks and chambers are heated to about 90°C. About 0.5 ml. of distilled water is applied to the surface of each block at the point where a chromel-alumel thermocouple contacts the block. The termperature at that point is recorded on a strip chart recorder for each block. Examination of the shapes of the curves of the known density blocks indicates a correlation between curve and density, and indicates that the unknown block has a surface density of about 0.40 g/cm 3 . This is later verified by mechanical measurement.
EXAMPLE V
Five test blocks having painted surfaces with micro-pore distribution ranging between 0.1 and 10 volume percent are tested together with a painted surface having an unknown pore spectra. Each block is tested with a device of the sort shown in FIG. 1. About 0.1 ml. of low molecular weight alcohol is applied to the surface of each block. A copper-constantan thermocouple is held in contact with each painted surface as the alcohol is evaporated. The evaporation temperature/time curve is recorded for each test surface using a multi-channel strip recorder. The test is repeated for the unknown sample. By comparison of the curves, the pore spectra of the unknown surface is found to correspond to a standard which indicates that the painted surface porosity is greater than permitted for the application. The surface is, therefore, stripped and repainted. A re-test of the surface indicates the pore spectra to now be within acceptable limits.
Specific materials, components and mechanical arrangements have been detailed in the above description of preferred embodiments. These may be varies and other components may be used where suitable. Other variations, applications and ramifications of the invention will become apparent 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.
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A method and apparatus for measuring the porosity or density of a porous structure surface is disclosed. A controlled quantity of volatile liquid is applied to a porous surface and is allowed to evaporate. The temperature at the surface reaches equilibrium at the point necessary to supply the latent heat of vaporization of the liquid. This equilibrium temperature depends on the evaporation rate, which has been found to be a function of surface porosity. The porosimeter substantially eliminates other factors influencing evaporation rate, and measures and records the temperature at the surface. Once calibrated with samples of known porosity, this system is capable of making rapid, accurate surface porosity measurements.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electrical heating device, in particular for a motor vehicle with a layer structure held by a retaining device, comprising several heat generating elements and between these said elements heat dissipating elements and a control device for the control of the heat generating elements.
[0003] 2. Description of the Related Art
[0004] An electrical heating device of this nature is for example known from EP 1 691 579 which originates from the applicant.
[0005] The individual layers of the layer structure can with heating devices with corresponding conformity be glued together and/or pressed together under pretension from a spring, in particular when the layer structure is accommodated in an enclosed frame which forms the retaining device. Single electrical heat generating elements are held insulated from one another in the retaining device and generally, on a face side of the layer structure, for example in the longitudinal direction of the layer structure, are provided with electrical contact elements, via which certain heat generating elements can be electrically connected to the vehicle electrical system.
[0006] For forming the heat generating elements normally resistance heating elements, so-called PTC heating elements, are used with which overheating of the heat generating elements can be reliably prevented due to their control characteristic. Each heat generating element usually comprises several PTC heating elements arranged one behind the other in the longitudinal direction of the layer structure. Said heating elements lie flat on an electrically conducting and generally well thermally conducting surface, via which the heat generating elements are supplied with electrical energy and the heat generated is dissipated by thermal conduction. This flat surface is normally formed by the heat dissipating elements, which for this purpose have on their outer side a sheet metal band which contacts a heat generating element and which is connected as a separate component or integrally with heating ribs or plates essentially extending transverse to the layer structure. Where the flat surface is formed by flat sheet metal bands, they are generally assigned to the heat generating elements. The sheet metal bands can in this respect form a prefabricated unit with the PTC heating elements.
[0007] For the open or closed-loop control of the electrical heating device it has a control unit which controls the heat generating elements. The control device can here comprise electronic control elements and/or conventional relays.
[0008] Following the general trend in the automotive industry, the electrical heating devices for motor vehicles are also prepared as modules which often means that the control device is mounted on the retaining device as part of the electrical heating device or is at any rate arranged adjacent to it. Thus, it is known for example from EP 1 157 867 that a control device for the control of the heat generating elements can be arranged within the frame and formed using power transistors, which have cooling fins on the side facing the layer structure. A similar arrangement is known from EP 1 492 384, which can similarly be regarded as forming a generic class and in which the control device is accommodated in the frame and similarly formed by power transistors. Also here there is the necessity of dissipating the heat loss produced by the transistors to the air flowing through the electrical heating device so that the control device is provided within the retaining device. An alternative design solution is known from EP 1 691 579 mentioned in the introduction, in which the control device is accommodated in a separate housing at the side of the frame and is mainly formed from switching relays which do not dissipate any loss.
[0009] The arrangement of the control device in the retaining device or adjacent to the retaining device particularly with mounting of the control device directly on the retaining device has the problem in that noises produced during switching can penetrate relatively easily into the passenger compartment with the conveyed air where they can be heard by the passengers in the motor vehicle. Sounds produced by the control device can however also for example be passed into the interior as structure-borne noise via the walls of the ventilation ducts. In this case even relatively slight acoustic disturbances produced by the control device can be amplified by the walls in the hollow ventilation ducts, so that acoustic disturbance of the occupants of the vehicle is not only to be expected when traditional mechanically switching relays in the control device switch.
OBJECT OF THE INVENTION
[0010] The object of the present invention is to reduce the effect of disturbing acoustic noise on the occupants of the vehicle.
[0011] This object is solved according to the invention by an electrical heating device with the features of claim 1 .
[0012] Preferred further developments are given in the dependent claims.
[0013] With the electrical heating device according to the invention the control device is essentially surrounded by a circumferentially closed sound deadening housing. This sound deadening housing can completely or almost completely circumferentially enclose the control device and is formed such that sound waves emanating from the control device are at least partially absorbed. In this respect both those sound waves are preferably absorbed which otherwise propagate as structure-borne noise as well as those which are carried along by the air flowing through the electrical heating device. The sound deadening housing should be formed such that sound waves produced by the control device are preferably absorbed directly at the control device. The electrical heating device according to the invention has proved to be particularly effective with embodiments with which the control device is arranged at the side on the retaining device and is joined to it. In particular with these embodiments there is the problem that sound waves penetrate relatively unhindered to the occupant cell through structure-borne noise and through the air passing through the electrical heating device.
[0014] Further advantages and details of the invention are given in the following description of an embodiment in conjunction with the drawing. This shows the following:
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 a perspective side view of the embodiment;
[0016] FIG. 2 a perspective exploded illustration of the housing of the embodiment enclosing the control device;
[0017] FIG. 3 a perspective plan view of a housing element of the housing according to FIG. 2 ;
[0018] FIG. 4 a perspective plan view of an internal housing of the embodiment illustrated in the FIGS. 1-3 and
[0019] FIG. 5 a plan view of the inner housing illustrated in FIG. 4 from the other side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] FIG. 1 illustrates the main parts of the electrical heating device. This comprises a two-part plastic housing 2 , in which a layer structure with several heat generating elements and intervening heat dissipating elements are held and pretensioned by a spring device described in more detail in the following. The heat dissipating elements 4 can be seen as meandering, curved sheet metal strips. Between said strips and behind longitudinal struts 6 , which pass through a housing opening 8 formed by the plastic housing 2 , there are heat generating elements running parallel to the longitudinal struts 6 and which cannot be recognized. In the central region of the housing opening 8 the layer structure has been removed and a spring strip 10 can be seen from which spring webs protrude inwardly. The spring strip 10 is introduced through an insertion slot 12 formed on the face side, as is described in EP-A-1 432287 which originates from the applicant.
[0021] On the plastic housing 2 enclosing the layer structure a sound deadening housing 14 is arranged on the face side. The sound deadening housing 14 comprises essentially a second housing element accommodating a control device 16 and a first housing element arranged between it and the plastic housing. The first housing element is labeled with the reference numeral 18 , the second housing element with the reference numeral 20 . The first housing element 18 is joined both to the second housing element 20 and also to the plastic housing 2 .
[0022] The first housing element 18 has on its underside facing the plastic housing flange segments 22 with holes for mounting the embodiment on the ventilation duct of a motor vehicle. Furthermore, the first housing element 18 forms on its underside a circumferential sealing groove 24 which interacts with ridges formed on the ventilation duct in order to seal the plastic housing 2 , which is pushed into the ventilation duct which it transversely passes, to the outside. From the underside of the first housing element 18 single-part, T-shaped latching tongues 26 also protrude down, which are latched with the plastic housing 2 .
[0023] On the upper side facing away from the underside the first housing element 18 forms a single-part housing cover 30 with a rectangular base area ( FIG. 2 ), said housing cover being formed by reinforcing ribs 28 and stiffened opposite the flange segments 22 .
[0024] This housing cover 30 fits between a collar 32 running externally around the second housing element 20 and sound deadening plates 34 , accommodated in the second housing element 20 and protruding from it. Apart from the sound deadening plates 34 , which can be seen in FIG. 2 and which circumferentially clad the interior of the sound deadening housing 14 , further sound deadening plates can be provided on the inner side of the housing cover 30 or on the bottom of the second housing element 20 . With the illustrated embodiment the bottom of the second housing element 20 is nevertheless not occupied with a deadening plate 34 and has a design which is described below. The housing cover 30 can have a sound deadening plate which is closely located to the face sides of the circumferentially provided sound deadening plates 34 .
[0025] The sound deadening plates 34 are cut from a foam plastic with a relative high density and precisely fitted into the second housing element 20 . In the illustrated embodiment the sound deadening plates 34 have a thickness of between 4 mm and 6 mm, preferably a thickness of 5 mm. As further measures in the sound deadening encapsulation of the interior of the sound deadening housing 14 , a sound deadening layer is provided between the collar 32 and the circumferentially arranged sound deadening plates 34 , for example in the form of an inlaid seal or in the form of a sound deadening element formed by means of two-component injection moulding on the first or second housing element 18 , 20 , said sound deadening element being provided according to a type of sealing lip preferably on the face side on the housing cover 30 or on a sealing edge 36 of the second housing element 20 which can be seen in FIG. 3 , surrounded circumferentially by the collar 32 . Through this sound deadening layer, the two housing elements 18 , 20 are brought together in a soundproof manner.
[0026] As can be seen from FIG. 3 , holders 38 for electrically conducting contact springs 40 protrude from the bottom 52 of the second housing element 20 . Contact lugs electrically connected with the individual heat generating elements engage in these contact springs 40 , said contact lugs being formed regularly by sheet metal bands, which at any rate partially form a locating face for the PTC heating elements and are brought out at the side via the face side of the plastic housing 2 . To achieve this, the first housing element has slot-shaped insertion openings 42 , which are illustrated in FIG. 2 , to which transversely broken up longitudinal webs 44 are recessed, single part, on the underside of the first housing element 18 , their conically running web edges 46 leading hopper-shaped to the insertion openings 42 , thus easing the introduction of the contact lugs into the insertion openings 42 . As can be seen from the illustration in FIG. 3 , the holders 38 are formed by slotted tubes 48 , which are stiffened at the base by reinforcing ribs 50 against the bottom 52 of the second housing element 20 . These tubes 48 have a transverse slot 54 which is formed in an extension of the reinforcing ribs 50 and which only partially passes through the slot 48 . Furthermore, the tubes 48 have a cable slot 56 cut out at right angles to this, which extends down to the vicinity of the bottom 52 .
[0027] In the second housing element 20 an inner housing 60 is inserted which is illustrated in more detail in FIGS. 4 and 5 . The inner housing is preferably formed from a sound deadening material and is for example an injection molded part in a foamed plastic. The inner housing 60 has an inner housing base 62 , which has a cross-section of essentially a U-shape and to which an inner housing cover 64 is supported for swiveling. The inner housing base 62 forms three control element accommodation spaces 68 , separated by partition walls 66 . Each control element accommodation space 68 can have further sound deadening partition walls, which are shown as examples in FIG. 4 and are identified with reference numeral 70 . The face side of a side wall 72 of the inner housing base 62 forms locating faces 74 for circuit boards 76 , which are protruded beyond by the partition walls 66 extending at right angles to them and are separated from one another by them. On these locating faces 74 the circuit boards 76 are located of which in FIG. 4 only one circuit board 76 is shown as an example. The other circuit boards have been omitted in the illustration.
[0028] It can be seen that the face side of the partition walls 66 and the upper side of the circuit board 76 are at about the same height. The closed inner housing cover 64 is located on this surface. The circuit board 76 and the inner housing cover 64 protrude beyond the side wall 72 . This protruding part of the circuit board 76 is used for the connection of electrical connecting leads 78 , 80 and control leads 82 . Control elements, for example relays, which cannot be seen in the figures, protrude from the inner side of the respective circuit boards 76 into the control element accommodation spaces 68 . The control elements for each circuit board 76 are in each case accommodated in a control element accommodation space 68 separated by the partition walls 66 and which is divided by the other partition walls 72 .
[0029] The connecting leads 80 leading to the circuit boards 76 are formed by extensions of a central feeder cable 84 . The further ground leads 86 lead to the inner housing 60 . These ground leads 86 and the connecting leads 78 leaving the circuit boards 76 each have one contact spring 40 at the end in each case, which is electrically connected to the corresponding leads 78 , 86 . The leads 78 , 80 connected to the circuit boards 76 initially extend essentially parallel to the side wall 72 and are then passed in front of a further side wall 88 which transversely passes through the housing 14 in the fitted state.
[0030] As can be seen particularly in FIG. 5 , the circuit boards 76 protrude beyond the respective connecting leads 78 , 80 at the connection point. Furthermore, the inner housing cover 64 at this point protrudes beyond the inner housing 60 as well as the circuit boards 76 . The embodiment of an inner housing 60 illustrated in FIG. 5 can be formed as a pre-assembled component. In this respect it is sufficient if the inner housing cover 64 is located on the circuit boards 76 . It is in particular not necessary that the inner housing cover 64 is fixed with respect to the inner housing base 62 . Fixing of this nature can however be realized with the prefabricated component.
[0031] For mounting the inner housing 60 on the second housing element 20 this has a receptacle provided on the bottom 52 into which the protruding edge of the inner housing cover 64 can be fitted as also the ends of the circuit boards 76 on insertion into the housing 14 . In this arrangement illustrated in FIG. 3 the inner housing cover 64 is located on the assigned sound deadening plate 34 . The pre-assembled inner housing 60 contacts the bottom 62 formed from plastic only via the face side of the inner housing cover 64 , which is formed from a sound deadening material. The sound deadening material is a silicone-free plastic, preferably a relative soft plastic, such as for example polyurethane, which ensures a certain deadening support of the inner housing 60 via the material forming the inner housing 60 . A polyurethane plastic with a hardness of ASHORE A between 50 and 90 has proven practicable. The receptacle is dimensioned such that the inner housing cover 64 fits precisely into the receptacle with the circuit boards 76 . Optionally, with slight compression of the sound deadening material of the inner housing cover 64 , a press fit can also be realized so that the inner housing 60 is fixed to the sound deadening housing 14 via the receptacle. The receptacle can for example be formed by recesses, ribs, webs or similar features on the bottom 52 by means of injection moulding as a single part on the housing 14 . Alternatively, it is possible to form a receptacle by single and/or between single sound deadening plates 34 .
[0032] During the assembly of the embodiment, first the prefabricated component is inserted into the second housing element 20 . Then the contact springs 40 are pushed into the respective transverse slots. While doing so, the connecting leads 78 or the ground leads 86 are pushed into the cable slot 56 where they are accommodated.
[0033] A first cable opening 90 is cut out on the second housing element 20 for bringing out the leads 80 or 86 ; a second cable opening 92 is cut away for the control leads 82 . The two openings 90 , 92 are each covered on the upper side by the first housing element 18 and thus simplify the insertion of the respective leads 80 , 82 , 86 .
[0034] The embodiment presented above has the advantage that the individual circuit boards 76 are accommodated with the associated control elements in separate control element accommodation spaces. The situation is avoided in which a common circuit board for all control elements of the control device is provided which as a resonating body would unnecessarily amplify emitted sounds. Since the inner housing 60 is formed with the associated circuit boards 76 and the leads 78 , 80 , 82 , 86 connected to it as a prefabricated component, this component can first of all be prefabricated and the sensitive control elements sealed by fitting the inner housing cover 64 onto the inner housing base 62 . With the ensuing mounting of the prefabricated component on the sound deadening housing 14 the control elements are thus protected from impact. Also, the circuit board is prevented from becoming contaminated on its sensitive sections. The circuit board 16 is only free at its section protruding from the inner housing base 62 , which has no sensitive electrical or electronic regions. Due to the receptacle formed on the second housing element 20 for inserting the prefabricated inner housing 60 , the inner housing and the sound deadening housing 14 can be easily joined.
[0035] Since the sound emitting control elements are on one hand enclosed by the inner housing and on the other hand supported in a sound deadening manner by the inner housing cover 64 with respect to the sound deadening housing 14 and furthermore are surrounded by the sound deadening plates 34 , the best possible sound insulation is achieved. The propagation of sound is in particular also reduced by an airtight sealing of the housing. In this respect, the flat plug contacts introduced into the housing 14 from the radiator are for example passed through a lip seal formed by means of two-component injection moulding. Using appropriate seals, the openings 90 or 92 can also be provided with sealing for the passage of the leads 80 , 86 , the said sealing being formed on the housing 14 by means of two-component injection moulding.
[0036] The special design of the tubes 48 facilitates a simple and precisely fitting assembly of the contact springs 40 introduced with the prefabricated component. The design also facilitates automatic insertion of the contact springs 40 into the tubes 48 .
[0037] A subunit of the control device 16 is then accommodated in each of the control element accommodation spaces 68 . Each of these control subunit devices, separately accommodated in the inner housing 60 , is in itself soundproofed. The control subunit devices control by open or closed-loop preferably proportionally the complete heating power of the electrical heating device. With the illustrated embodiment three control subunit devices are provided, which then each control one third of the heating power of the whole heating device. In this way a better adaptation of the electrical energy consumed by the electrical heating device to a generator power of the motor vehicle can be achieved. The electrical heating power can with the illustrated embodiment then be switched to one third, two thirds or three thirds of the maximum heating power. Taking into account the switching capacity of the relays, the heating power of the switching circuits can be designed however different one to the other. The grading of the respective heating powers of a single switching circuit should here be selected such that the whole heating power can be switched in the smallest possible stages, despite the division giving just three switching circuits, using elaborate on/off switching of the individual switching circuits. With the illustrated embodiment only relays are used as the control element.
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An electrical heating device for a motor vehicle has a layer structure held by a retaining device. The heating device has several heat generating elements and heat dissipating elements between the heat generating elements, and a control device for controlling the heat generating elements. The heating device has a sound deadening housing, which circumferentially encloses the control device and by which sound waves produced by the control device are deadened. Through this measure, disturbing exposure of persons located in the vehicle to structure-borne noise and/or to sound waves borne by the air flowing through the electrical heating device is prevented.
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BACKGROUND OF THE INVENTION
In the field of model racing vehicles, such as road racing cars, there have been proposed means for steering the vehicles to change lanes and pass one another, all under remote control of an operator. However, such lane changing model vehicles have not been entirely satisfactory, involving complex steering and driving mechanisms readily subject to damage and malfunction, including the need for shiftable components of substantial mass, complex cam surfaces and followers, unrealistic operation by single wheel drive, and other difficulties.
Examples of the above mentioned prior art are found in the below listed U.S. patents:
______________________________________3,731,428 3,717,952 3,239,9633,742,875 3,878,521 3,447,2573,748,780 3,482,352 3,772,8243,765,693 3,600,851 3,797,4043,799,544 3,780,470 3,837,2863,827,693 3,961,441 3,813,8123,774,340 2,993,299______________________________________
SUMMARY OF THE INVENTION
Accordingly, it is an important object of the present invention to provide a model vehicle construction which overcomes the above-mentioned difficulties, is extremely simple in structure for economy in manufacture and reliability in operation, being selectively remotely operable to shift from one lane to another within a trough type roadway for movement along a selected one of the roadway side walls or confining barriers.
Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.
The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view showing a model vehicle constructed in accordance with the teachings of the present invention, partly broken away to illustrate internal construction, and illustrating its operational relationship with a trough-type roadway or track.
FIG. 2 is a longitudinal sectional view taken generally along the line 2--2 of FIG. 1.
FIGS. 3 and 4 are partial sectional elevational views taken generally along the lines 3--3 and 4--4 of FIG. 1.
FIG. 5 is an exploded perspective view illustrating the rear wheel drive clutch mechanism of the present invention.
FIG. 6 is a partial perspective view illustrating a trough-type track construction for use with the instant model vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, and specifically to FIGS. 1 and 2 thereof, a model vehicle is shown therein and generally designated 10, including an elongate, generally horizontally disposed frame or chassis 11 having a bottom wall 12 extending forwardly to a forward region 13, and rearwardly to an open rearward region 14.
Rear wheeled running gear, generally designated 15, are mounted by the rear chassis portion 14, and forward wheeled running gear, generally designated 16, are mounted by the forward chassis region 13.
The rear wheeled running gear 15 may include a generally horizontally disposed, laterally extending axle or shaft 20 axially rotatably supported by and extending laterally through and beyond opposite sides of the rear chassis region 14. Carried by opposite, outboard ends of rear axle 20 are respective left and right rear wheels 21 and 22, being keyed or otherwise rotatable with the axle.
The forward or front running gear 16 may include a laterally extending, generally horzontal wheel carrier or axle means 25 extending laterally across the forward chassis region and mounted thereon for swinging movement about an upstanding pivot or pin 26. As best seen in FIG. 2, the swingable member or axle means 25 is spaced over the forward chassis region 13, and the pivot or pin 26 upstands from the forward chassis region through a medial location of the member 25 to mount the latter for pivotal movement about the vertical, laterally medial axis of pivot 26. An end enlargement or head 27 may be provided on the upper end of pivot 26 to retain the axle means 25 on the pivot.
Extending from opposite ends of the member 25 may be suitable wheel bearing means or journals 28 and 29 respectively rotatably carrying left and right front wheels 30 and 31.
The cross axle member 25 is provided on its rearward side with a rearwardly facing cutout or notch 35, proximate to and just rearward of the pivot 26, for a purpose appearing presently.
Upstanding from the forward chassis region 13, adjacent to opposite sides thereof and rearward of the transverse member or beam 25, are a pair of abutments or stop members 36 and 37. The stop member 37 is located to limit pivotal or swinging movement of the axle beam 25 in the rightward direction, by abutting engagement therewith, while the abutment or stop member 36 is located to limit axle beam swinging movement to steer in the leftward direction, as in the phantom position of the forward steerable running gear 16.
Extending laterally across the forward end of chassis 11 is a bumper, runner or guide member 40 which terminates at its opposite ends 41 and 42 laterally outwardly beyond the forward wheeled running gear 16. Thus, upon steering movement of the vehicle 10 toward a track side wall the front bumper 40 runs along the side wall for limiting engagement therewith.
The pivotable axle member or beam 25 is also provided laterally medially thereof with a forward projection or arm 45 forward of the pivot 26 and swingable with the beam rightward and leftward of the pivot. Just forward of the axle beams 25, laterally medially of the forward chassis region 13, and just rearward of the forward member or bumper 40, there may be provided an upstanding lug or boss 46. A torsion spring on other suitable resiliently expansile member 47 may have its opposite ends respectively extending into the axle beam extension 45 and lug 46, so as to resiliently, yieldably urge the same apart from each other. Thus, the resilient means or spring 47 will serve to snap the wheeled front running gear 16 toward their adjacent limiting position of steering movement. Hence, upon movement of the axle beam 25 to a position slightly beyond dead center, the resilient means or spring 47 will serve to continue pivotal movement of the axle beam toward its adjacent limiting position of steering movement, as shown in solid and phantom positions in FIG. 1.
A rotary motive means or electric motor 50 is mounted in the midregion of the chassis 11, extending longitudinally of the chassis and having forwardly and rearwardly extending stub shafts 51 and 52, respectively. The motor 50 is provided with electrical connections to current collectors, as at 53 in FIG. 2, beneath the chassis 11 for wiping engagement with track conductors in the conventional manner.
The axle member or beam 25 on its vertical pivot 26 and carrying wheels 30 and 31 may be considered as constituting the front wheeled running gear or steering means 16. Interposed between the dirigible front wheeled running gear or steering means 16 and the motive means or motor 50 is a steering gear operating means generally designated 55. Specifically, the steering gear operating means may include a pinion or gear 56 carried by the forward end shaft 51 of motor 50 for rotation therewith generally about the longitudinaly center line of the chassis. Just forward of the gear or pinion 56, and in alignment therewith longitudinally of the chassis, is provided an upstanding pin or shaft 57, say upstanding from a boss 58 on the chassis 11. An arm 59 extends generally radially from the pin 57, having at one end an eye 60 rotatably circumposed about the pin. The arm is provided with a rotary pinion or gear 61 rotatable about the arm 59 and swingable or rotatable with the arm about the pin 57. Suitable retaining means 62 may be provided on the arm 59 for rotatably retaining the pinion 61 on the arm.
Circumposed about the pin 57, rotatably thereon, and superposed over the eye 60 and pinions 56 and 61 is a generally circular crown or ring gear 65 having its teeth in meshing engagement with the teeth of both pinions 56 and 61. Thus, rotation of pinion 56 will effect rotation of gear 65 to drive pinion 61. As there is an additional gear 70 below and with its teeth extending upwardly toward the teeth of gear 65, forward of pin 57, which also meshes with pinion 61, the arm 59 is caused to swing about pin 57 upon rotation of pinion 56. However, the lower or upwardly facing gear 70 is of limited extent, being an arcuate segment only, or may be considered as an upwardly facing ring or crown gear having tooth interruption throughout a major portion of its extent. The interrupted lower crown gear or segment 70 is of such a length as to cause the arm 59 to swing about pin 57 a predetermined angle from the longitudinal center line illustrated in FIGS. 1 and 2, after which the pinion 61 rides off of or beyond the gear 70. The free outer end 71 of arm 59 extends into the rearwardly facing cutout or notch 35, and engages therein to swing the steering gear 16 beyond dead center, whereupon resilient means 47 continues movement of the steering gear to its other limiting position. In this manner, rotation of the motor 50, and its forward stub shaft 51 in opposite directions, effects movement of the steering gear 16 in opposite steering directions. As the pinion 61 rides beyond the gear segment 70 to prevent jamming of the steering gear operating means upon continued rotation of pinion 56 and crown gear 65, opposite directional rotation of the pinion 56 and steering gear 65 causes the pinion 61, by pivotal friction thereof, to rotate arm 59 toward and effect meshing engagement of pinion 61 with segment gear 70 to effect opposite directional steering movement in the same manner described hereinbefore.
Interposed in driving relation between the reversible direction motor 50, its rear stub shaft 52 and the rear wheeled running gear 15 are clutch means generally designated 75. In particular, the clutch means 75 includes a pair of clutches 76 and 77, which are essentially identical but oppositely arranged to effect forward driving rotation of the wheeled running gear 15 upon rotation of motor 50 in opposite directions.
The clutch 76 may include a crown or ring gear 80 rotatably circumposed about shaft or axle 20 on one side of the longitudinal center line of chassis 11 and in meshing engagement with a gear or pinion 81 keyed to the rear motor shaft 52, for rotation of the gear 80 by the motor. The other clutch 77 similarly includes a crown or ring gear 82 rotatably circumposed about the axle 20 on the opposite side of the chassis center line as gear 80, and in meshing engagement with the pinion 81 on the opposite side of the latter as gear 80. Thus, the crown gears 80 and 82 are rotated in opposite directions by the motor 50. The interior of crown gear 80 is provided with a tooth 83 of generally ratchet-like formation, including an abutment face or surface 84 generally radially of the gear 80, and a cam face or side 85, generally arcuate about the center of gear 80. The ring gear or crown gear 82 is similar to the ring gear 80, including an internal ratchet-like tooth 86 having an abutment surface or side 87 extending generally radially of the gear, and a relatively inclined cam side or surface 88 generally tangential to the gear.
A hub 90 is keyed or otherwise fixed to the axle 20 intermediate the crown gears 80 and 82, and is provided at opposite ends with radially elongate formations or bosses 91 and 92 located interiorly of respective gears 80 and 82. A disc-like engaging member 93 is disposed within ring gear 80, circumposed about axle 20 and provided with a generally central elongate slot 94 slidably receiving the boss 91. Thus, the engaging member or disc 93 is constrained to rotation with the axle 20 and hub 90, while being shiftable radially thereof within the limits of slot 94, the latter being of greater radial extent than the received boss 91. On its circumference, the engaging member or disc 93 is provided with one or more ratchet-like teeth 95 arranged for abutting engagement with the adjacent ratchet tooth 83 of ring gear 80 upon rotation in one relative direction, and adapted to cam past or ride over the tooth 83 upon relative rotation in the other direction.
Similarly, a disc-like engaging member 96 is circumposed about the shaft 20 and boss 92 within the ring gear 82, being provided centrally with a slot 97 slidably receiving and of greater radially extent than the boss 92 for radial shifting relative to the latter. The engaging member or disc 96 is provided on its peripheral edge with one or more ratchet-like teeth 98 configured for abutting driving engagement with the adjacent tooth 86 of ring gear 82 in one direction of relative movement between the disc and ring gear, and configured to cam past or ride over the ring gear tooth in the other direction of relative rotation.
Thus, upon ring gear rotation in the direction of solid line arrow in FIG. 5, the ring gear 80 defines an annular drive member with its tooth 83 in driving engagement with a tooth 95 of the plate-like disc or engaging member 93. As the engaging plate 93 is, by its slot 94 nonrotatably receiving boss 91, rotatable with the axle 20, the latter is driven to rotate wheels 21 and 22 to drive the chassis forwardly.
Upon rotation of ring gear or drive member 80 in the direction of arrow 100, the tooth 83 rides over the teeth 95 so that the gear rotates relative to the engaging member 93 and axle 20.
Operation of the clutch 77 of FIG. 4 is identical to that described in connection with the clutch means 76 in FIG. 3, however, by the opposite orientation of the clutch means 77 its associated wheel 22 is driven in the forward direction by the clutch means when the motor 50 drives the gear 80 in the direction of arrow 100. It will therefore be seen that the motor 50 serves to drive through the clutch means 76 and 77, the rear drive wheels 21 and 22 in the forward driving direction when the motor is driven in either of its rotative directions.
As noted hereinbefore, the motor 50 serves to steer the steering gear 16 in opposite directions corresponding to opposite directions of motor rotation.
In operation of a model vehicle 10 within a trough-like track 101, as shown in FIG. 6, it will presently be apparent that the vehicle is capable of movement along either track lane, as selected, and to change lanes, as desired. The track 101 for use with the instant model vehicle is of a trough-type kind, including a bottom wall 102 of plural lanes, being two lanes in the illustrated embodiment. Upstanding from opposite side edges of the track bottom wall 102 are a pair of upstanding side walls or confining barriers or rails 103 and 104. In the solid line position of FIG. 1, it will be seen that the model vehicle 10 is moving rightward along track 101, the steering gear 16 being directed rightward with the bumper or guide member 40 riding along the rightward side wall or rail 103 of the track. Obviously, the side wall or rail 103 is essential to retain the vehicle 10 on the track bottom wall 102, as the front wheeled steering gear 16 is directed rightward against the side wall 103. When it is desired to changes lanes on the track 101, it is only necessary to reverse the direction of rotation of motor 50. This will not reverse the direction of rotation of the driving rear wheels 21 and 22, as discussed hereinbefore. However, it will swing operating arm 71 clockwise, as seen in FIG. 1, to rotate the steering gear 16 counterclockwise to its phantom line position. This will, of course, cause the vehicle to move leftward into the opposite lane of track 101 and ride against the other barrier side wall or rail 104 with its guide member or bumper 40. Reversal of the above described procedure may be achieved by mere reversal of the direction of motor 50, so as to complete a "road passing" operation.
From the foregoing, it is seen that the present invention provides a model vehicle for movement along a trough-type track which is remotely actuable to effect lane changing and passing, being extremely simple in construction for realistic and reliable operation throughout a long useful life, and which otherwise fully accomplishes its intended objects.
Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention.
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A model vehicle of the steerable road racing type for confined movement along a trough type roadway or track of plural land width including a dirigible wheeled chassis carrying a drive motor, a clutch mechanism operative to drive the wheeled running gear continuously in forward direction upon actuation of the motor in opposite directions, and an operating mechanism steering the running gear in opposite directions responsive to the motor running in opposite directions for controlling vehicle movement between lanes and along a selected trough side wall.
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FIELD OF THE INVENTION
The present invention relates in general to a data processing system, and more particularly to a method and apparatus for providing operand feed forward support in a data processing system.
BACKGROUND OF THE INVENTION
It is important to provide a useful and cost effective approach for allowing emulation and debug of a data processing system, particularly when the data processing system is implemented on an integrated circuit with limited pins or terminals to communicate information. Most emulation and debug approaches provide a mechanism to allow observability and controllability of portions of circuitry within the data processing system. One such emulation and debug approach is the OnCE™ circuitry and methodology used on a variety of integrated circuits available from Motorola, Inc. of Austin, Tex. The use of serial scan chains is yet another approach that may be used. In addition, the serial scan approach may take advantage of the JTAG (Joint Test Action Group) specification which defines a hardware interface and a serial communication protocol.
In determining an approach to be used for emulation and debug of a data processing system, a tradeoff is usually required between the ease of use and the amount observability and controllability on the one hand, and the amount of special emulation and debug circuitry that must be added on the other hand. A solution was needed which would allow the maximum observability and controllability for emulation and debug as possible, while adding the least amount of special emulation and debug circuitry that is not also used during normal operation. In a solution was needed which would allow maximum observability and controllability, but which would not significantly impact the internal operation and speed of the data processing system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates, in block diagram form, a data processing system 10 in accordance with one embodiment of the present invention;
FIG. 2 illustrates, in block diagram form, a portion of processor 12 of FIG. 1 in accordance with one embodiment of the present invention;
FIG. 3 illustrates, in timing diagram form, an example of operand feed-forward in accordance with one embodiment of the present invention; and
FIG. 4 illustrates, in block diagram form, a scan chain 100 in accordance with one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The term "bus" will be used to refer to a plurality of signals or conductors which may be used to transfer one or more various types of information, such as data, addresses, control, or status. The terms "assert" and "negate" will be used when referring to the rendering of a signal, status bit, or similar apparatus into its logically true or logically false state, respectively. If the logically true state is a logic level one, the logically false state will be a logic level zero. And if the logically true state is a logic level zero, the logically false state will be a logic level one.
DESCRIPTION OF THE FIGURES
FIG. 1 illustrates one embodiment of a data processing system 10 which includes a processor 12, a debug module 14, a memory 18, other modules 20, and external bus interface 22 which are all bi-directionally coupled by way of bus 28. Alternate embodiments of the present invention may not include one or more of memory 18, other modules 20, and external bus interface 22 as part of data processing system 10. Note that other modules 20 may include any type of functional circuitry, such as, for example, a timer, a serial port, additional memory of any type, I/O ports, etc. Also, debug module 14 may use a wide variety of techniques for providing emulation and debug signals external to data processing system 10.
Still referring to FIG. 1, external bus interface 22 is bi-directionally coupled external to data processing system 10 by way of integrated circuit terminals 35. Processor 12 may optionally be coupled external to data processing system 10 by way of integrated circuit terminals 31. Debug module 14 may optionally be coupled external to data processing system 10 by way of integrated circuit terminals 32. Note that debug module 14 may convey emulation and debug information external to data processing system 10 by way of integrated circuit terminals 32 and/or by way of bus 28, external bus interface 22, and integrated circuit terminals 35. Memory 18 may optionally be coupled external to data processing system 10 by way of integrated circuit terminals 33. Other modules 20 may optionally be coupled external to data processing system 10 by way of integrated circuit terminals 34. Debug module 14 provides a SCAN DATA IN signal 29 to processor 12 and receives a SCAN DATA OUT signal 30 from processor 12. Debug module 14 and processor 12 are also bi-directionally coupled by way of control/status conductors 27.
FIG. 2 illustrates one embodiment of a portion of processor 12 of FIG. 1. In one embodiment, processor 12 includes registers 50, which comprise a register file, are coupled to multiplexer (MUX) 54 by way of conductors 71, and are coupled to multiplexer (MUX) 56 by way of conductors 72. Registers 50 include a program counter (PC) register 51, as well as a plurality of other address, data, and control registers. Multiplexer 54 is coupled to arithmetic logic unit (ALU) 52 by way of conductors 73. Multiplexer 56 is coupled to ALU by way of conductors 74. The output of ALU 52 is coupled to write back bus register (WBBR) 70. The WBBR register 70 is coupled to registers 50 by way of conductors 75, which may be considered as the "write back bus" used to write a result value from ALU 52 back to a destination register. The WBBR register 70 is also coupled to an input of multiplexer 54 and to an input of multiplexer 56 by way of conductors 75.
Control circuitry 58 includes control register (CTL) 62, instruction register (IR) 66, and processor status register (PSR) 68. In one embodiment of the present invention, control register 62 includes a feed forward source Y (FFY) bit 64 and a feed forward source X (FFX) bit 65. Alternate embodiments of the present invention may implement only a feed-forward control bit for one of the source operands, i.e. either source operand X only, or source operand Y only. Alternate embodiments of the present invention may have more than two source operands (X, Y, Z, etc.) and may use one bit for each source operand. Also, alternate embodiments of the present invention may encode the functionality of one or more of the feed forward source bits 64, 65 into one or more bits that also source other functions.
Still referring to FIG. 2, control circuitry 58 includes feed forward control circuitry 60 which provides a FEED FORWARD X operand signal 78 to multiplexer 54 and which provides a FEED FORWARD Y operand signal 79 to multiplexer 56. Control register 62 receives a SCAN DATA IN signal 29. Control circuitry 58 is bi-directionally coupled to control/status conductors 27. Control circuitry 58 is bi-directionally coupled to ALU 52 by way of conductors 77 in order to provide and receive control and status information. Control circuitry 58 is bi-directionally coupled to registers 50 by way of conductors 80 to provide and receive status and control information. Control circuitry 58 is bi-directionally coupled to bus 28 by way of conductors 82. Registers 50 are bi-directionally coupled to bus 28 by way of conductors 81. Processor status register (PSR) 68 is coupled to write back bus register (WBBR) 70 in order to provide a scan input by way of conductor 76. The WBBR register 70 then provides a SCAN DATA OUT signal 30.
FIG. 3 illustrates an example of operand feed forward in accordance with one embodiment of the present invention.
FIG. 4 illustrates one embodiment of an emulation and debug serial scan chain 100 utilized by the present invention. In the embodiment illustrated in FIG. 4, SCAN DATA IN signal 29 is provided as a serial input to bit 15 of control register (CTL) 62. Bit 0 of control register 62 is serially coupled to bit 15 of instruction register 66. Bit 0 of instruction register (IR) 66 is serially coupled to bit 31 of program counter register (PC) 51. Bit 0 of program counter register 51 is serially coupled to bit 31 of processor status register (PSR) 68. Bit 0 of processor status register 68 is serially coupled to bit 31 of write back bus register (WBBR) 70. Bit 0 of write back bus register 70 is serially coupled to provide the SCAN DATA OUT signal 30 from processor 12 to debug module 14 (see FIG. 1).
OPERATION OF THE PREFERRED EMBODIMENT
The operation of the present invention will now be discussed. In one embodiment, the present invention provides a mechanism to load a predetermined value into a selected register or memory location during emulation or debug. In addition, the present invention does not require parallel loads of the busses within processor 12 (see FIG. 2) and does not require dedicated addressable registers that are used only during emulation and debug and serve no useful purpose during normal operation of data processing system 10 (see FIG. 1).
Instead of requiring additional emulation and debug circuitry, the present invention reuses existing registers and latches in processor 12 and couples them in a serial scan chain 100 (see FIG. 4). In one embodiment of the present invention, a feed forward source Y control bit (FFY) 64 is used to indicate whether or not the predetermined value stored in the write back bus register (WBBR) 70 is to be loaded as the source operand Y into MUX 56. By allowing the predetermined value stored in the WBBR register 70 to be "fed forward" and forced as the source operand Y of ALU 52, instructions can be executed by processor 12 in emulation and debug mode which store the contents of the WBBR register 70 into a user selected register in registers 50 or into user selected memory locations in memory 18 (see FIG. 1).
In alternate embodiments of the present invention, a feed forward source X control bit (FFX) 65 is used to indicate whether or not the predetermined value stored in the write back bus register (WBBR) 70 is to be loaded as the source operand X into MUX 54. By allowing the predetermined value stored in the WBBR register 70 to be "fed forward" and forced as the source operand X of ALU 52, instructions can be executed by processor 12 in emulation and debug mode which store the contents of the WBBR register 70 into a user selected register in registers 50 or into user selected memory locations in memory 18 (see FIG. 1). Note that memory 18 may alternately be located on a different integrated circuit that data processing system 10 and may be accessed by processor 12 by way of bus 28, external bus interface 22, and integrated circuit terminals 35.
Referring to FIG. 1, in one embodiment of the present invention data processing system 10 has a debug module 14 which is used to control debug and emulation processing. Debug module 14 communicates with processor 12 by way of the SCAN DATA IN signal 29, the SCAN DATA OUT signal 30, and control/status conductors 27. The serial scan chain 100 formed by SCAN DATA IN 29 and SCAN DATA OUT 30 is illustrated in FIG. 4. In one embodiment of the present invention the registers illustrated in FIG. 4 have been selected to be included in the scan chain. In alternate embodiments of the present invention, different registers, fewer registers, or more registers could be included in this scan chain 100.
The registers included in scan chain 100 are also illustrated in FIG. 2 as part of processor 12. In one embodiment of the present invention, the processor status register (PSR) 68 and the program counter register (PC) 51 are considered part of the programmer's model, whereas write back bus register (WBBR) 70, control register (CTL) 62, and instruction register (IR) 66 are merely internal latches available within processor 12 that are used during normal operation of processor 12, but that are not normally available for direct access by the user. However, scan chain 100 allows all of the registers in FIG. 4 including write back bus register (WBBR) 70, control register (CTL) 62, and instruction register (IR) 66 to be accessible by the user in emulation or debug mode. Allowing access to these registers by way of serial scan chain 100 provides a significant advantage for debug and emulation. For example the feed forward source Y bit 64 may be used in conjunction with the write back bus register (WBBR) 70 in order to allow the user to load a predetermined value into a selected register or memory location by substituting the predetermined value as the intended Y operand. Similarly, the feed forward source X bit 65 may be used in conjunction with the write back bus register (WBBR) 70 in order to allow the user to load a predetermined value into a selected register or memory location by substituting the predetermined value as the intended X operand.
Referring to FIG. 3, an example of operand feed forward is illustrated. Although the example in FIG. 3 shows normal instruction execution operation, the feed forward mechanism illustrated in FIG. 3 is the same mechanism used in debug and emulation mode to substitute the predetermined value store in the WBBR register 70 for the X and/or Y source operand to ALU 52. Note that the user may load the predetermined value into the WBBR register 70 by way of the SCAN DATA IN signal 29 during emulation and debug mode. The debug module 14 (see FIG. 1) is used to provide the proper values to the SCAN DATA IN signal 29.
FIG. 3 illustrates the execution of an add instruction followed by a subtraction instruction. During clock cycle 1 the add instruction is fetched. Note that the R1 register is the source of the X operand and the R2 register is source of the Y operand. During clock cycle 2 the next instruction, a subtract instruction, is fetched while concurrently the add instruction is decoded and the R1 and R2 registers are read from registers 50. During clock cycle 3, the subtract instruction is decoded and registers R3 and R1 are read from registers 50. Concurrently during clock cycle 3, the add instruction is executed with the result of the add instruction being stored in write back bus register (WBBR) 70 in preparation for the update of register R1 with the result value. However, since the subtract instruction requires the result of the add instruction as the Y operand, the R1 register value read from registers 50 during clock cycle 3 is discarded and the add result value stored in the write back bus register (WBBR) 70 is fed forward into MUX 56 by way of conductors 75. Therefore the add result value is "fed forward" to ALU 52 by way of conductors 74 as the updated Y operand for the subtract instruction.
Referring to FIGS. 2 and 3, the present invention uses the same feed forward mechanism from write back bus register (WBBR) 70 to MUX 56 by way of conductors 75 in order to substitute a predetermine value for the Y source operand that would normally be provided from registers 50. Feed forward control circuitry 60 provides the control to MUX 56 by way of conductor 79 in order to select this feed forward path from write back register (WBBR) 70.
Still referring to FIG. 3, during clock cycle 4 the feed forward value from write back bus registers (WBBR) 70 is used as the Y operand during the subtract operation. Concurrently, the result from the add instruction, which is presently stored in write back bus register (WBBR) 70, is provided to registers 50 by way of conductors 75 in order to update the R1 register with the result of the addition operation. During clock cycle 5, the result of the subtract instruction, which is now stored in write back bus register (WBBR) 70, is used to update register 3 in registers 50 by way of conductors 75.
In one embodiment of the present invention the feed forward control circuitry 60 provides the control to multiplexers 54 and 56 in order to allow the feed forward of operands to ALU 52 to take place. Note that feed forward control circuitry 60 receives the feed forward source Y bit 64 and the feed forward source X bit 55. If the FFY bit 64 is zero then feed forward will occur if the RY field of the instruction currently being decoded will be taken from the write back bus register 70 of the instruction currently being executed. Similarly if the FFX bit 65 is zero feed forward will occur if the RX field of the instruction currently being decoded is the same as the result value stored in the write back bus register (WBBR) 70 of the instruction currently being executed. However if the FFY bit 64 equals 1, then feed forward of the Y operand is forced and always occurs regardless of the instructions are currently being decoded and executed. Similarly if the FFX bit 65 is asserted, then feed forward is forced and always occurs regardless of the instructions currently being decoded and executed.
In one embodiment of the present invention, the FFY bit 64 may be negated by feed forward control circuitry 60 after a single instruction has been executed while the FFY bit 64 was asserted. In this manner, only a single predetermined value is loaded into a selected register or memory location from the WBBR register 70 by using a single move, load, store, or other processor 12 instruction. Similarly, the FFX bit 65 may be negated by feed forward control circuitry 60 after a single instruction has been executed while the FFX bit 65 was asserted. In this manner, again, only a single predetermined value is loaded into a selected register or memory location from the WBBR register 70 by using a single move, load, store, or other processor 12 instruction. Alternate embodiments of the present invention may not automatically clear the FFY bit 64 and the FFX bit 65 after a single instruction has been executed. Alternate embodiments of the present invention may use a different approach, including a user programmable approach, for clearing the FFY bit 64 and the FFX bit 65.
By allowing feed forward to be forced using one or more of the FFX bit 65 and the FFY bit 64, the user of data processing system 10 can scan selected values into scan chain 100 (see FIG. 4) in order to load a predetermined value into write back bus register (WBBR) 70, which can then be loaded into a selected register or memory location by using move, load, store, or other processor 12 instructions having a designated destination from ALU 52.
While the present invention has been illustrated and described with reference to specific embodiments, further modifications and improvements will occur to those skilled in the art. It is to be understood, therefore, that this invention is not limited to the particular forms illustrated and that the appended claims cover all modifications that do not depart from the spirit and scope of this invention.
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The present invention relates in general to a data processing system (10), and more particularly to a method and apparatus for providing operand feed forward support in a data processing system (10). In one embodiment, a scan chain (100) may be combined with a feed forward source Y (FFY) bit (64) to allow a user to update registers (50) and memory (18) during emulation and debug. In one embodiment, feed forward control circuitry (60) forces the content of the WBBR register (70) to be used as the Y source operand value for the first instruction to be executed following an update of scan chain (100). This allows debug module (14) to update processor registers (50) and/or memory (18) by initializing the WBBR register (70) with the desired value, asserting the FFY bit (64), and executing a processor (12) move instruction to the desired register in registers (50).
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BACKGROUND OF THE INVENTION
The present invention relates to a lighted knob provided with a lighted indicator which illuminates a character, symbol, or numeral at night and, more particularly to a lighted knob which illuminates to facilitate the discrimination of whether or not a nameplate for indicating control items has been properly mounted in a specific position.
Various types of equipment are provided with knobs for performing on-off operation and predetermined control operation of the equipment. As these knobs, lighted knobs have been in wide use for the ease of identification of their control purpose or on-off condition by illuminating a nameplate on the knobs in order to ensure correct knob manipulation even in the gloom and at night.
A lighted switch knob for opening and closing a slide roof of an automobile will be explained as one example of the lighted knob by referring to FIGS. 4 and 5.
FIG. 4 is a plan view showing the switch knob with the nameplate removed, and FIG. 5 is a vertical cross section, partly cut off, of the switch knob.
A lighted knob 1 to be operated to open and close a slide roof is fitted, on a body 5, with three nameplates: a control item nameplate 2 placed at the center thereof to indicate the operation of the slide roof; a first operation nameplate 3 placed beside the control item nameplate 2, for closing the roof; and a second operation nameplate 4 for opening the roof. The control item nameplate 2 has a code "ROOF" in relief indicating a control item; the first operation nameplate 3 is formed to indicate the contour of a car in relief; and the second operation nameplate 4 is formed to indicate the contour of a car in relief with the roof opened. The knob body 5 is produced from a synthetic resin and provided with three light transmission holes 6, 7 and 8 drilled in the front part and covered with the three nameplates 2, 3 and 4. On the peripheral edge of each of the light transmission holes 6, 7 and 8 is formed a step section 9 lowered at least by the thickness of the nameplates 2, 3 and 4. The peripheral edge section of the nameplates 2, 3 and 4 is bonded to the step section 9 with an adhesive. Each of the nameplates 2, 3 and 4, the details of which constitution is not illustrated, is composed of a nameplate sheet on which a transparent character, contour, etc. for example are printed, and a transparent, heat-resisting protective sheet affixed on the back side through an adhesive layer. Also, when a colored character or contour is used, filling a clear colored ink between the nameplate sheet and an adhesive layer is sufficient. Behind the knob body 5 are arranged light sources 11, 12 and 13 for illuminating the nameplates 2, 3 and 4 respectively. A projecting wall 14 provided on the back side of the knob body 5 serves to shield the light from an adjacent light source.
Since most nameplates have a symmetrical shape such as rectangular and square as illustrated, incorrect assembling is very likely to occur by securing the nameplates 2, 3 and 4 upside down to the light transmission holes 6, 7 and 8 respectively at the time of lighted knob assembling. Furthermore, in the above-described lighted knob 1, the first and second operation nameplates 3 and 4 are of the same size and therefore there will also occur an error in assembling the knob in which the second operation nameplate 4 is secured to the light hole 7 for the first operation nameplate 3.
In order to prevent such an incorrect assembling, there are adopted nameplate sheets of different shapes, and the knob body is provided with a receiving section which conforms to these shapes, and also is provided with a recess. At the same time the nameplate is provided with a projection, which fits in the recess. However, if various many types of nameplate sheets are prepared, many kinds of dies also will be needed correspondingly, resulting in an increased cost and complicated parts control.
SUMMARY OF THE INVENTION
It is therefore a first object of the present invention to provide a lighted knob by which an operator can see the presence of a specific indicating member in a knob case simply by checking whether or not the incorrect assembly preventive light is lit, thereby preventing incorrect assembling by the use of a simple constitution; and also it is possible to commonly use a plurality of nameplates when needed, thus enabling to reduce the number of components, lower a production cost, and further to decrease the cost of dies.
It is a second object of the present invention to provide a low-cost lighted knob of very simple constitution which requires no member for shielding the incorrect assembly preventive light section.
It is a third object of the present invention to provide a lighted knob of such a design that a specific indicating member, if not mounted in a specific translucent section, will not be shielded, so that the operator can see at a glance whether or not the specific indicating member is properly mounted, and also can prevent incorrect assembling such as affixing the indicating member upside down.
The first object is accomplished by the use of a first means comprising a knob case having at least one translucent section, an indicating member at least one part of which to be mounted to the translucent section indicates a knob purpose by light transmission, a light source for illuminating the indicating member from the translucent section, an incorrect assembly preventive light section formed in the indicating member, and a shield section formed on the knob case to shield the incorrect assembly preventive light section when the indicating member is properly mounted to the translucent section of the knob case.
The second object is accomplished by the use of a second means comprising a knob case having at least one translucent section, an indicating member at least one part of which to be mounted to the translucent section indicates a knob purpose by light transmission, a light source for illuminating the indicating member from the translucent section, an incorrect assembly preventive light section formed in the indicating member, and a shield section formed on the peripheral edge of the translucent section, and by mounting the indicating member in such a position that the incorrect assembly preventive light section will correspond to the shield section.
The third object is accomplished by the use of a third means which has, in the second means, a plurality of translucent sections in the knob case, in which the shield sections of the light transmission sections are formed in different positions.
In the first means stated above, the incorrect assembly preventive light section is shielded when the indicating member is properly mounted to cover the translucent section of the knob case; therefore simply by checking to see if the incorrect assembly preventive light section is lit, it is possible to see that the specific indicating member is mounted on the knob case and accordingly to thereby prevent incorrect assembling and to commonly use a plurality of nameplates when needed, resulting in a decreased number of components, reduced cost, and lowered cost of dies.
In the second means, since the shield section for shielding the incorrect assembly preventive light section is mounted in a part of the translucent section, it is unnecessary to mount a separate shield member for shielding the incorrect assembly preventive light section and therefore a low-cost lighted knob is suppliable. When a plurality of translucent sections are provided, the shield sections are provided in different positions; and therefore no shielding is effected unless the specific indicating member is mounted in the specific translucent section, enabling the operator to see whether or not the indicating member is properly mounted. That is, the operator can prevent such incorrect assembling as affixing the indicating member upside down.
BRIEF DESCRIPTION OF THE DRAWINGS
All the foregoing and still further objects and advantages of this invention will become apparent from a study of the following specification, taken in connection with the accompanying drawings, wherein:
FIG. 1 is a plan view showing the mounted condition of a nameplate of one embodiment according to the present invention;
FIG. 2 is a plan view showing one embodiment of a lighted knob according to the present invention with each nameplate off;
FIGS. 3A, 3B and 3C are explatory views showing incorrectly assembled lighted knobs.
FIG. 4 is a plan view showing one example of a conventional lighted knob with each nameplate off; and
FIG. 5 is a longitudinal cross section, partly cut off, of said conventional lighted knob.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter one embodiment of a lighted knob according to the present invention will be explained with reference to the accompanying drawings.
FIG. 1 is a plan view showing the mounted condition of a nameplate of one embodiment of the present invention; FIG. 2 is a plan view showing a nameplate of the embodiment prior to mounting to a knob body; and FIGS. 3A, 3B and 3C are explanatory views showing incorrectly assembled condition of nameplates. Components of the substantially same constitution as those of the above-described conventional example are designated by the same reference numerals and therefore will not be explained to prevent redundancy.
In the present embodiment also, an example of a knob for opening and closing an automobile slide roof is described similarly to the above-described conventional example. The knob body 5 of the lighted knob 1 has three light transmission holes 6, 7 and 8 to which the control item nameplate 2, the first operation nameplate 3 and the second operation nameplate 4 are mounted. On the peripheral edge of each of the light transmission holes 6, 7 and 8 is formed the step section 9. Behind the knob body 5 are arranged unillustrated light sources 11, 12 and 13 for illuminating the nameplates 2, 3 and 4 respectively as shown in FIG. 5 of the above-described conventional example, in such positions that the light from an adjacent light source will be intercepted by the projecting wall 14.
In a part of the nameplates 2, 3 and 4 are a hole-like incorrect assembly preventive light section 21, 22 and 23. Of these the light sections in the first operation nameplate 3 and the second operation nameplate 4 have the same shape. To prevent incorrect assembling of these nameplates, therefore, the incorrect assembly preventive light sections 22 and 23 are formed in different positions. When the nameplates 2, 3 and 4 are mounted to the specific light transmission holes 6, 7 and 8, shield sections 24, 25 and 26 which protrude toward the center are formed, in a part of the peripheral edge of the light transmission holes 6, 7 and 8, to intercept the light from the light sources 11, 12 and 13 correspondingly to the incorrect assembly preventive light sections 21, 22 and 23. The shield sections 24, 25 and 26 are positioned on the same plane as the step section 9.
Therefore, when the nameplates 2, 3 and 4 are properly mounted on the light transmission holes 6, 7 and 8 respectively, the incorrect assembly preventive light section 21 of the nameplate 2 is closed by the shield section 24, the incorrect assembly preventive light section 22 of the nameplate 3 by the shield section 25, and the incorrect assembly preventive light section 22 of the nameplate 4 by the shield section 25 as shown in FIG. 1. These incorrect assembly preventive light sections 21, 22 and 23, therefore, will not illuminate. However, if the nameplates 2, 3 and 4 are attached upside down on the specific light transmission holes 6, 7 and 8, the incorrect assembly preventive light sections 21, 22 and 23 of the nameplates 2, 3 and 4 will not be closed by the shield sections 24, 25 and 26 as shown in FIGS. 3B and 3C. That is, since the incorrect assembly preventive light sections 21, 22 and 23 illuminate, the nameplates 2, 3 and 4 thus attached upside down can easily be found.
Also, the incorrect assembly preventive light sections 22 and 23 of the first operation nameplate 3 and the second operation nameplate 4 are formed to be mounted in different positions; and the positions of the shield sections 25 and 26 also differ. Therefore, when the first operation nameplate 3 is mounted, if properly, to the light transmission hole 8 or the second operation nameplate 4 to the light transmission hole 7 as shown in FIG. 3A, the incorrect assembly preventive light sections 22 and 23 of the nameplates 3 and 4 will illuminate without being closed by the shield sections 25 and 26. The operator, therefore, can easily see the nameplates 3 and 4 have been improperly mounted to the light transmission holes 7 and 8. The nameplates of the same shape and dimensions can be attached in position.
In the present embodiment, the incorrect assembly preventive light sections 21, 22 and 23 and the shield sections 24, 25 and 26 are formed at the corner section of the nameplates 2, 3 and 4 and the light transmission holes 6, 7 and 8 but may be provided in other places. The incorrect assembly preventive light sections 21, 22 and 23 may be formed by drilling and also transparent holes may be formed by printing similarly to transparent characters, contour, etc. of the nameplates.
While the invention has been described with reference to a specific embodiment, the description is illustrative and is not to be construed as limiting the scope of the invention. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
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A lighted knob including a knob body provided with light transmission holes, and nameplates through at least a part of which the light from light sources passes. And in a part of the nameplates are formed incorrect assembly preventive light sections; and on a part of the peripheral edge of the translucent sections are formed shield sections, so that the incorrect assembly preventive light sections will not be shielded unless the specific nameplates are attached to specific translucent sections.
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FIELD OF THE INVENTION
This invention relates generally to the fabrication of small geometry planar metal oxide semiconductor (MOS) field-effect devices. More particularly, the invention relates to a fabrication process for MOS field-effect devices with insulated gates, in which the alignment of the source and drain regions and their contact areas is significantly improved, and the size of the source and drain regions is minimized, thereby forming devices exhibiting increased speed of performance.
BACKGROUND OF THE INVENTION
In the fabrication of field-effect transistors (FETs) with self-aligned gates, it has been a common practice to use an insulated gate structure in conjunction with the field oxide of a device as the mask for the formation of the source and drain regions thereof. This process allows precise positioning of the source and drain regions of a device with respect to the channel over which the gate electrode exerts its effect and thus avoids undesirable effects such as stray capacitance and ohmic and non-ohmic losses. These self-aligned gate processes have been carried out using both solid state diffusion and ion implantation, as described respectively by H. G. Dill in U.S. Pat. No. 3,544,399 and by R. W. Bower in U.S. Pat. No. 3,472,712, both assigned to the present assignee. After the source and drain regions of a self-aligned gate FET have been established and a surface passivation layer formed thereon, holes are etched in the passivation layer covering these regions using established masking procedures to define and limit the size of the contact holes. Finally, the metal contacts are established using well-known photoresist lift-off techniques which include forming a resist pattern, depositing the metal layer over the resist pattern and then removing the resist pattern to remove portions of the metal layer thereon.
During the prior art formation of the source and drain regions for these insulated-gate FETs, it is customary to use one set of photoresist masking steps to define the lateral extent of these regions. This may be accomplished by using the photoresist mask as an ion-implantation mask per se, or as a means of defining (by etching) the necessary ion implantation mask in another surface material. In either case, in order to properly make the necessary subsequent direct ohmic contacts to these source and drain regions with a chosen metallization pattern and insure that such contacts are sufficiently within the lateral boundaries of these source and drain regions to avoid metallization overlap on the source and drain junctions, it becomes necessary to closely align a second photoresist mask with these previously formed source and drain regions and insure that the etch openings in the second photoresist mask (required for SiO 2 removal) are sufficiently within the lateral boundaries of the source and drain regions to prevent PN junction shorting. Since it is known that these mask-to-mask alignment tolerances may cause a variation of as much as 50% in the planar dimensions of the contact area, and since there is a minimum required source and drain silicon surface ohmic contact area corresponding to given current and power requirements of a particular device, these mask-to-mask alignment tolerances impose a limit on the size reduction of devices made by this prior art process. To a large degree, this size reduction limitation establishes or limits the maximum achievable operating or cut-off frequency for these devices. It is the removal of this latter limitation to which the present invention is directed.
SUMMARY OF THE INVENTION
The general purpose of this invention is to provide a new and improved process for fabricating self-aligned gate field-effect transistors in which the required resist mask-to-mask tolerances have been substantially reduced relative to prior art processes while simultaneously minimizing the size of the FET source and drain regions and their respective contact areas in the completed FET devices. It is a more specific purpose of this invention to eliminate a requirement in prior art fabrication processes that an etch opening in a resist mask for metallization pattern definition lie wholly within the lateral boundaries of the FET source and drain regions.
To accomplish these purposes, I have discovered and developed an improved field-effect transistor fabrication process wherein initially a passivation layer is provided on the surface of a semiconductor body. Then, a high temperature-resistant gate electrode member is formed on the surface of the passivation layer and defines one lateral boundary of an active region of a device. Next, a permanent, insulating mask which is etch-resistant and an impurity barrier is formed on the surface of the passivation layer and is spaced from the gate electrode member so as to define another lateral boundary of the above active region of the device. Chosen impurities are then introduced through an exposed area between the gate electrode and the permanent, insulating mask, whereby a doped active device region is formed. Finally, metal contact to the active region is established by first removing a portion of the passivation coating which covers the active device region and then depositing a metallization pattern over a portion of the permanent, insulating mask and into electrical contact with the doped region of the device. Thus, the insulating mask functions (1) as an impurity mask to define the lateral dimension of an active region of the device; (2) as an etch mask during the selective removal of portions of the passivation coating; and (3) as a support for the metallization pattern. In the fabrication of MOS field-effect transistors, two active device regions are formed simultaneously using this process and serve as the source and drain regions of the transistor.
In another embodiment of the invention, during the formation of a metal contact to the active device region or regions, the resist mask which is used for etching the passivation coating to define metal contact openings therein is also used as the mask for the formation and definition of the metal pattern thereof, thus eliminating one masking step required in the previously described embodiment of this invention.
Accordingly, an object of this invention is to provide a new and improved process for fabricating metal oxide semiconductor field-effect devices and integrated circuits having predefined doped active device regions therein.
A further object of this invention is to provide a new and improved process for fabricating high speed, small geometry, refractory metal insulated-gate semiconductor devices and integrated circuits.
Another object is to provide a process of the type described for making MOS devices in which the substrate-to-source and substrate-to-drain capacitance is minimized and the device speed is thereby increased.
Still another object is to provide a fabrication process of the type described which improves the alignment of the source and drain junctions with their respective contact areas, thereby minimizing the size of these junction boundaries and their respective contacts.
A further object of this invention is to provide a fabrication process of the type described which includes the use of the same mask for contact hole formation and for metallization.
The foregoing and other objects and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a through 1j illustrate, in schematic cross-section and in process sequence, the successive fabrication steps utilized in one embodiment of the invention; and
FIGS. 2a through 2d illustrate in schematic cross-section and in process sequence, the fabrication steps utilized in another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention is concerned with alleviating the problems of mask-to-mask alignment which arise when successive resist patterns must be established in the fabrication of certain MOS semiconductor devices. In the preferred embodiment of this invention, photoresist masks are specifically described. It is to be understood, however, that other resist patterns, such as electron beam, ion beam and x-ray resists, may also be used.
Referring now to FIG. 1a, there is shown a semiconductor body 2 which may be of N-type silicon, for example, having a typical resistivity of 0.1 to 10 ohm-centimeters, and upon which a layer of a surface passivation material 4 has been deposited. A suitable surface passivation material is silicon dioxide, SiO 2 , which may be formed by heating the silicon semiconductor body 2 in an oxidizing atmosphere, at 1000° C., to produce a layer of SiO 2 which is typically 1000 angstroms thick. Next, a high temperature-resistant gate 6, such as a polysilicon gate, typically 1 micron in length, is formed on the surface passivation layer 4, such as by depositing a layer of polycrystalline silicon 3000A thick over the surface passivation layer 4 using standard evaporation at 600° C. or electron beam sputtering techniques and subsequently using known photolithographic masking and etching techniques to selectively remove the silicon and leave the desired gate member in place as shown. Other suitable high temperature-resistant refractory gate materials are tungsten, tantalum, molybdenum, platinum, palladium, or a metal silicide, all of which are capable of withstanding temperatures up to 600° C., and which may be formed by chemical vapor deposition. After the polysilicon gate 6 has been formed, a protective layer 8 of silicon dioxide is formed over the gate 6 by exposure to a suitable oxidizing atmosphere at elevated temperature or by the SILOX process of heating to 380° C. in a mixture of silane and oxygen. If the gate 6 is formed of one of the other high temperature-resistant materials specified herein, the protective layer 8 is formed over the gate 6 by chemical vapor deposition of an oxide layer.
The next step in the process is to deposit an etch-resistant insulating layer 10 over both the passivation layer 4 and the gate-protection insulating layer 8 as shown in FIG. 1b. The layer 10 is an insulating material which is an impurity barrier during ion implantation or diffusion, an etch-resistant protective barrier during silicon dioxide etching and a support for a metallization pattern subsequently deposited thereon. This insulating material may be selected from the group of materials consisting of silicon nitride, aluminum nitride, aluminum oxide, silicon carbide, titanium oxide, and boron nitride. Preferably, the layer 10 is silicon nitride (Si 3 N 4 ), and is between 0.2 to 1.0 micron in thickness, which is a sufficient thickness to provide an impurity barrier during ion implantation. The silicon nitride layer 10 may be deposited by heating a dilute (for example, 5%) mixture of silane in nitrogen, with ammonia to 925° C., to vapor deposit Si 3 N 4 . Then portions of the Si 3 N 4 layer 10 are etched away in the regions 20 and 22 and the region between regions 20 and 22 which overlies gate-protection layer 8, as indicated in FIG. 1c, to define the lateral boundaries of the source and drain regions and to expose the gate member with its protection layer 8. Typically, an electron beam resist (not shown) such as polymethylmethacrylate may be deposited on the Si 3 N 4 layer 10 and then developed in a 1:3 solution of 2-propanol and methylisobutylketone to form the desired resist pattern. Then, etching is performed using a suitable etchant, e.g., a phosphoric acid solution, that is preferential for Si 3 N 4 . Etching may also be performed using carbon tetrafluoride (CF 4 ) gas and plasma etching techniques well-known in the art.
After the Si 3 N 4 has been removed from regions 20 and 22, the structure of FIG. 1c is subjected to an ion implantation or diffusion step to introduce chosen P-type impurities into the silicon substrate 2, thereby producing active device regions to be described. (If a P-type substrate is used, then N-type impurities are introduced by ion implantation or diffusion.) For convenience, this discussion considers the details of ion implantation. It is to be understood, however, that well-known diffusion processes can also be used. With the structure of FIG. 1c transferred to an ion implantation chamber, P-type ion beams 24 and 26 of FIG. 1d are suitably focused on the exposed areas of the SiO 2 layer 4 covering the silicon layer 2 to modify the impurity concentration in regions 28 and 30 and form the planar PN junctions indicated in FIG. 1d. The active device regions, which in this embodiment of the invention are source and drain regions 28 and 30, thus formed are self-aligned both to the gate member 6 and to the edges of the insulating (silicon nitride) layer 10, as indicated in FIG. 1d.
Ion implantation processes, which are well known in the art, involve ionizing impurity atoms such as boron and phosphorus and then accelerating these ions by an electric field into the crystal lattice of the exposed semiconductor substrate. In this particular instance, a typical ion dose of 5×10 14 ions/cm 2 at 30-40 KeV is used to implant to a depth of less than 0.5 microns. The SiO 2 layer 4 covering the substrate in the path of the ion beams is sufficiently thin to allow the ion beams to pass through to the underlying silicon substrate 2. After implantation, the device is annealed by heating to a suitable elevated temperature such as 950° C., to electrically activate the implanted regions. The source and drain region 28 and 30 thus formed have typical lateral dimensions of 1 micron by 2 microns and typical resistivities of 0.001 ohm-centimeter.
After ion implantation has been completed, contact holes are etched and metal contacts are established as shown in FIGS. 1e through 1j. The first step in this portion of the process is to apply a photoresist material 12 which is suitable for oxide etching and, using standard photolithographic processing, to establish the desired photoresist mask as shown in FIG. 1e. It should be noted that the alignment of the photoresist mask with the nitride edges 34 and 36 of FIG. 1e is not critical when practicing this invention, since the nitride layer 10 that has previously been established will also mask the oxide etchant. This feature is of utmost significance in that mask-to-mask alignment tolerances now require that only the central gate-contact portion of the photoresist mask 12 be aligned as shown to expose a central region of the thin oxide layer 8; and the precise location at which the peripheral portions of the photoresist layer 12 meet the underlying Si 3 N 4 layer is not critical. Next, portions of the SiO 2 layers 4 and 8 are etched away in the regions 38, 40 and 42 as shown in FIG. 1f, thus exposing the active device regions 28 and 30 and the polysilicon gate 6. An oxide etchant such as dilute hydrofluoric acid, HF, which is selective for SiO 2 and does not significantly affect the Si 3 N 4 is used, and consequently the size of the source and drain contact holes 38 and 40 is limited by the Si 3 N 4 mask as well as by the photoresist mask. Since the contact holes are aligned to the same nitride edges as the source and drain regions, these regions can now be originally made much smaller than would have been the case if an opening is a subsequently used photoresist mask provided total lateral definition for the source and drain ohmic contact openings.
Since the capacitance between the source or drain region and the substrate is directly proportional to the area of junction between the two, the reduced PN junction area made possible by the present invention minimizes this capacitance, which is typically 10 4 picofarads/cm 2 , and makes circuits of higher speed possible. Furthermore, the reduced ohmic contact area permits a greater packing density, which in turn allows a higher level of integration in a given area. In addition, the procedure can tolerate some misalignment of the resist window used for defining the electrical contacts without affecting the size of the source and drain areas. After the etching procedure illustrated in FIG. 1f has been completed, the photoresist layer 12 is then removed to yield the structure shown in FIG. 1g.
The next step in the process is to deposit a layer 14 of metal, such as aluminum, using conventional aluminum evaporation techniques in order to provide the structure shown in FIG. 1h. Other suitable materials for metallization in this step are tungsten, molybdenum, titanium-platinum-gold multilayer, and titanium-palladium-gold multilayer. Then, a photoresist material which is suitable for metal etching is applied on top of the metal layer 14 and the desired photoresist mask 16 is established therein as shown in FIG. 1i. Next, the metal layer 14 is etched away in the regions 44 and 46 overlying outer portions of the gate insulator 4 as shown in FIG. 1i. The photoresist layer 16 is then removed by conventional methods to produce the structure of FIG. 1j, which includes metal contacts 48, 50 and 52 to the active device source and drain regions 28 and 30 and the polysilicon gate 6, respectively. The metal contacts 48 and 50 to the active device source and drain regions 28 and 30 have typical lateral dimensions of 1 micron by 1 micron.
Referring now to FIG. 2, a second embodiment of the invention is shown which differs from that in FIG. 1 in the sequence followed for contact hole formation and metallization, with the elimination of one masking step relative to the number of steps used in FIG. 1. FIG. 2a shows a structure which is obtained in the same manner as that produced by the process described for FIGS. 1a through 1e; that is, the silicon nitride mask has been formed, ion implantation has been performed and the photoresist material 12' which is suitable both for oxide etching and for metallization pattern definition has been applied and developed to form the desired surface resist mask 2'. Next, portions of the SiO 2 layers 4' and 8' are etched away in regions 38', 40' and 42' as shown in FIG. 2b and in a manner similar to that described above for FIG. 1f. After the contact holes 38', 40' and 42' have been etched and with the photoresist 12' still in place, a layer 14' of metal, such as aluminum, is deposited on the upper surface of the photoresist layer 12' using conventional aluminum evaporation techniques, thereby providing the structure shown in FIG. 2c. Thus, in this embodiment of the invention, the same photoresist mask 12' is used both for oxide etching to form contact holes and for establishing the metal pattern that connects the source, drain and gate structures, thereby eliminating one masking step and the associated mask-to-mask alignment problems. Thus, this embodiment of the invention serves to further minimize the size of the metal contacts to the active device regions. The use of the insulating layer 10' is essential to both process embodiments of the invention. Without this etch-resistant insulating layer 10', the oxide overlying the non-implanted silicon substrate would also be etched when contact holes are formed and could provide undesirable exposure of the underlying substrate and when metal is subsequently deposited, the PN junctions defining source and drain regions could be shorted, rendering the device inoperable.
Finally, the photoresist layer 12' is lifted off using conventional resist lift-off techniques to yield the final structure shown in FIG. 2d, which provides metal contacts to the active device regions 28' and 30' and to the polysilicon gate 6'.
While the invention has been particularly described with respect to the preferred embodiments thereof, it will be recognized by those skilled in the art that certain modifications in form and detail may be made without departing from the spirit and scope of the invention. In particular, the scope of this invention is not limited to the insulated gate field-effect transistors described, but includes charge transfer devices, such as charge-coupled devices, and other devices which utilize a self-aligned insulated gate to modify the flow of information on each side of that gate. In addition, although the preferred embodiments of this invention which are described indicate that ions are implanted through a passivation layer which covers the areas where the active device regions are to be formed, this invention applies as well to processes in which ions are implanted through a mask directly into the areas where the active device regions are to be formed. It should be further understood that while the fabrication of a single device is described, in practice a large number of identical devices may be simultaneously formed on a common semiconductor body, to form integrated circuits.
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The specification describes a process for making an insulated-gate field-effect transistor wherein a silicon nitride mask is deposited above the surface of a semiconductor body and is used in one embodiment of the invention in conjunction with a refractory gate member (1) as a mask in the formation of the source and drain regions by the ion implantation of conductivity-type-determining impurities on both sides of the gate and (2) as a mask in the formation of contact holes to the source and drain regions of the transistor for the subsequent provision of metal contacts to these regions. In another embodiment, there is described a process for forming source and drain contacts wherein the mask for the formation of contact holes by oxide etching is also the pattern definition and lift-off mask for the formation of metal contacts to the transistor.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an improved extension ladder structure, and more particularly to an extension ladder apparatus, which is assembled and folded easily and securely, providing superior safety.
[0003] 2. Description of the Prior Art
[0004] Accordingly, stepladders have become a requisite tool for casual use. For example, climbing tools such as a ladder or scaffolding enable people to readily process construction or obtain the objects at a high place.
[0005] A conventional stepladder 800 , as shown in FIG. 1 , is assembled by two side rails having a footpad respectively to prevent slippage, and is provided with parallel spaced step portions therein. The stepladder appears as an A-frame ladder during usage.
[0006] Stepladders are typically large and bulky; therefore, it is uneasy and inconvenient to carry them. Moreover, the storage of a folded stepladder may occupy large space, which makes the use of a stepladder inflexible.
[0007] Various extension ladder structures have been disclosed in U.S. Pat. Nos. 4,989,692, 5,492,430, 5,495,915, 2004/0195043A, 6,708,800, and 5,743,355 to improve the fixed stepladder as shown in FIG. 1A . However, the extension ladders in those applications still require respective control during folding and cannot achieve the automatic folding, which is not ideal for use.
[0008] To improve the shortcomings of existing extension ladders, the Chinese Patent No. 200620113407.6 named “Extension Ladder” has been issued on Apr. 29, 2006 and the Utility Model No. 899705 has been obtained.
[0009] Referring to FIG. 1B , which is the partial view of the extension stepladder in the Chinese patent No. 200620113407.6, after a locking mechanism within the first-length transverse step portion is pulled, with a tie rod plate 801 that can be held up and down, one end of the tie rod plate 801 extends to the upper end of the cross hole, the out-protruding part is inserted into the lower end cross hole 802 of the upper transverse step portion, and then the turning rod 803 disposed within the upper transverse step portion is pushed so that the locking bar withdraws from the upper transverse step portion to unlock. Accordingly, the locking mechanism above the second length can be unlocked in order and each length of the side rail sections will go down and be folded.
[0010] However, after the Chinese Patent No. 200620113407.6 described above has been completed, through constantly tests, it is found that when an extension ladder is used in a dirty environment, the holes above or under the step portions may be filled with dust and other contaminants so that the tie rod plate cannot be moved smoothly, which will cause unlock failure or other problems.
[0011] Also, unlocking requires the tie rod plate 801 to push the turning rod 803 . If a tie rod plate 801 gets stuck or cannot pass through the cross hole, the entire stepladder cannot be folded smoothly which causes inconvenience while using it.
[0012] As to the side rail sections that can be fit in with each other, since there is no effective locking mechanism, the upper side rail section may depart from the lower side rail section when they are used erroneously, which causes unsafety.
[0013] Accordingly, the present invention has been invented to solve the above-mentioned problems occurred in the prior art.
SUMMARY OF THE INVENTION
[0014] Accordingly, the present invention aims at improving an extension ladder structure which comprises a plurality of rail side sections, connection kits, locking mechanism and transverse step portion, makes the structure simpler, safer, and more stable, and can solve the above-mentioned problems occurred in conventional extension ladders. Since transmission parts are largely decreased, the parts that need further process and technology are also reduced, which save costs and reduce manufacturing difficulties. Furthermore, the locking mechanism is completely hidden, which can reduce the risk of mistaken unlocking. Also, a confirmation window for the locking bolt is provided in the present invention, which facilitates the safety confirmation before using the extension ladder.
[0015] In the improvement of an extension ladder structure in the present invention, a fixing ejection bar is provided at the upper end of the connection kit that is used to fit into the side rail section. A locking mechanism is provided within the connection kit. One end of the connection kit is covered by a transverse step portion. Accordingly, when the fixing ejection bar of the lower connection kit is inserted upward into the upper connection kit, the locking mechanism within the upper connection kit can be pushed to unlock. Since the ejection bar is a fixed device, any damage caused by external force or problems that lead to unable to perform operations can be avoided. This is another objective of the present invention.
[0016] In the improvement of an extension ladder structure in the present invention, an unlocking bock that can be fit into the upper end of the fixing ejection bar is provided, and an partition ejection bar that is equal to the ejection bar is provided at the upper end of the unlocking bock. When the unlocking bock is fit into the upper end of said fixing ejection bar, a locking mechanism within the upper connection kit can be pushed by the ejection bar, so that a space between the upper step portion and lower step portion remain during the folding, which allows cables or wires to be passed through or allows operators who need to wear gloves in a long time to hold the ladder easily when the extension ladder is used in any specific location. This is another objective of the present invention.
[0017] In the improvement of an extension ladder structure in the present invention, an elastic support set is disposed at the bottom of said extension ladder, which not only increases the basal area of said extension ladder and enhances the safety, but also suitable for adjustment in different places or uneven ground (step differences) to increase the applicable scope and locations and enhance the stability. This is another objective of the present invention.
[0018] In the improvement of an extension ladder structure in the present invention, a locking mechanism that will not be skidded is disposed between the upper side rail section and lower side rail section. This is another objective of the present invention.
[0019] The detailed structure, application principle, function, and effects of the present invention will be more apparent from the following descriptions taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a three-dimensional view of the conventional ladder;
[0021] FIG. 1B is a partial sectional view of the Patent No. 095108511;
[0022] FIG. 2 is an illustration showing the folding of the extension ladder in the present invention;
[0023] FIG. 3 is an illustration showing the extension of the extension ladder in the present invention;
[0024] FIG. 4 is a three-dimensional exploded view of the first-length rung section and its locking mechanism;
[0025] FIG. 5 is a partial sectional view of the embodiment in the present invention;
[0026] FIG. 6 is an exterior view of the rung section in the embodiment of the present invention;
[0027] FIG. 7 is a three-dimensional exploded view of the rung section above the second length and its locking mechanism in the embodiment of the present invention;
[0028] FIG. 8 is a three-dimensional assembly view of the embodiment in the present invention;
[0029] FIG. 9 is a three-dimensional view of the connection kits from another perspective in the embodiment of the present invention;
[0030] FIG. 10 is a plan view of the unfolded ladder in the embodiment of the present invention;
[0031] FIG. 11 is a plan view of the folded ladder in the embodiment of the present invention;
[0032] FIG. 12 is a three-dimensional view of the second embodiment of the present invention;
[0033] FIG. 13 is a plan view of the unfolded ladder in the second embodiment of the present invention;
[0034] FIG. 14 is an enlarged view of the part AB of the FIG. 13 .
[0035] FIG. 15 is a plan view of the third embodiment of the present invention;
[0036] FIG. 16 is a three-dimensional view of the elastic support set in the third embodiment of the present invention;
[0037] FIG. 17 is a partial plan view of the elastic support set in the third embodiment of the present invention;
[0038] FIG. 18 is a partial three-dimensional view of the elastic support set in the third embodiment of the present invention;
[0039] FIG. 19 is a three-dimensional exploded view of the fourth embodiment of the present invention;
[0040] FIG. 20 is an illustration showing the folding of the extension ladder in the present invention;
[0041] FIG. 21A is an enlarged view of the part A of the FIG. 20 ;
[0042] FIG. 21B is an enlarged view of the part B of the FIG. 20 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0043] The present invention discloses the improvement of an extension ladder structure wherein the extension ladder 1 can be folded as shown in FIG. 2 or unfolded as shown in FIG. 3 . Said extension ladder 1 comprises a plurality of side rail sections 2 , connection kits 3 , and transverse step portion 5 , which is present as a stepladder extending upward when it is unfolded and each of its side rail sections can be fit in with each other when it is folded.
[0044] Referring to FIG. 4 , each side rail section 2 of the extension ladder in the present invention is hollow and tubular-shaped and can be fit in with each other. That is, the second side rail section 2 a , which has a smaller diameter but the same shape with the first side rail section 2 , can be fit into the first side rail section 2 . The second side rail section 2 a can be slid within the first side rail section. Other side rail sections can be fit in with each other accordingly.
[0045] As shown in FIG. 4 , a snap-fit hole 21 and an orientation hole 22 are provided above the first side rail section so that the connection kit 3 can fit through the holes.
[0046] As shown in the figure, said connection kit 3 comprises a ringlike covering part 31 that can be fit through the upper end of a side rail section and a pivotal joint 32 extending toward from the ringlike covering part 31 ; after said ringlike covering part 31 is fit into the upper end of said side rail section by using a screw 33 to fix it, an orientation tenon 34 for embedding snap-fit hole 21 of the side rail section is provided on the internal wall of said side rail section; an adhesive channel 35 is provided whose one end is provided with an adhesive-infusing hole 36 so that adhesive can be infused therein to stick the side rail section together; a via hole 30 is provided on the ringlike covering part 31 . The via hole 30 is interlinked with the orientation hole 22 of the side rail section after the ringlike covering part 31 is fit in with its upper end.
[0047] Said pivotal joint 32 is formed with the ringlike covering part 31 and a channel 37 is formed therein which is interlinked with the via hole 30 . The two sides of said channel 37 are side plates 321 and 322 . A upright opening 38 is provided on the internal wall of said side plates 321 and 322 ; a transverse step portion 5 is fit in with the external part of the pivotal joint 32 ; a cross hole 51 is provided on the lower surface of the transverse step portion 5 .
[0048] A first-length locking mechanism 4 a , is provided in the interior of the channel 37 of the first-length connection kit 3 , which includes a block plate 41 , a locking bar 42 , a spring 43 , a pull rod 44 , and a control pad 45 ; said block plate 41 is inserted and fixed within the upright opening 38 of the pivotal joint 32 and a cross hole 411 is formed in the center of said pivotal joint 32 . After the joint part 441 of the pull rod 44 passes through the cross hole 411 , it is jointed with the end connection 421 of the locking bar 42 . One end of the locking bar 42 passes through the via hole 3 of the connection kit 3 and the orientation hole 22 of the side rail section 2 . A narrow opening 422 is provided in the main body of the locking bar 42 for a C-shaped plate 46 to be inserted into the narrow opening 422 to restrain the spring 43 . Accordingly, when the locking bar 42 is pushed and shifted by the pull rod 44 , the spring 43 needs to be used to return the locking bar 42 to its original position.
[0049] The block plate 41 , locking bar 2 , spring 43 , and pull rod 44 are disposed in the interior of the first-length locking mechanism 4 a described above, and are covered by a transverse step portion 5 . One end of the pull rod 44 is connected with the control pad 45 disposed under the transverse step portion 5 , so that the movement of locking bar 42 can be controlled manually by the control pad 45 ; a guide plate 451 is disposed above the control pad 45 , and a horizontal groove 452 is formed under the guide plate 451 , which can push the guide plate 451 into the cross hole 51 of the transverse step portion 5 . With the horizontal groove 452 , sliding along the edge of the cross hole 51 is available.
[0050] As shown in the figure, a through and fixing hole 23 is provided in the external part of the side rail section 2 a above the second length; a out-protruding ring 24 is provided under the through and fixing hole 23 ; a corresponding in-protruding ring 25 (as shown in FIG. 5 ) is provided in the interior of the first-length side rail section 2 . By way of the joint of the out-protruding ring 24 and in-protruding ring 25 , the side rail section 2 a is moved upward and downward within the first-length side rail section 2 so that the through and fixing hole 23 can be oriented to the orientation hole 22 of the first-length side rail section 2 and the locking bar 42 can pass through the through and fixing hole 23 . Accordingly, the upper side rail section and lower side rail section can be extended and fixed to some extent.
[0051] In addition, a buckle hole 26 is disposed at the lower end of the side rail section 2 a above the second length so that a buffering device 6 can be hooked in the buckle hole 26 of the side rail section through a protruding part 61 and can be fixed in the lower end of the side rail section 2 a ; an elastic seal ring 62 is disposed outside the lower end of the buffering device 6 so that appropriate friction remains from the internal wall of the side rail section since the elastic seal ring 62 is shifted upward and downward within the side rail section, which reduces the noise occurred. Said elastic seal ring 62 also has the folding cushion function. Also, a film 63 is disposed within the buffering device 6 . A hole is formed on the film 63 so that air can get into the film 63 through the hole to achieve the cushion effect when the buffering device 6 is shifted upward and downward.
[0052] As shown in FIG. 6 , to avoid that two side rail sections depart from each other, an in-protruding encircling ring part 201 is provided at the upper tube opening of side rail section in the present invention; an out-protruding ring part 202 is provided at the lower tube opening of side rail section. Accordingly, after the upper side rail section passes upward through the lower side rail section, the encircling ring part 201 and protruding ring part 202 restrain from each other, which prevents the side rail sections from departing from each other and ensures the safety.
[0053] Referring to FIG. 7 , the upper locking mechanism 4 b , upper connection kit 3 a , and upper transverse step portion 5 a of the side rail section 2 a above the second length are different from those in the first length side rail section. A cross hole at the lower end of the upper transverse step portion 5 a is not required.
[0054] As shown in the figure, the upper connection kit 3 a not only has the structure of first-length connection kit 3 but also has an axial opening 39 on the internal wall of the side plates 321 and 322 . Also, an opening 310 is provided at the bottom of the ringlike covering part 31 of connection kit 3 a which is connected with the pivotal joint 32 .
[0055] The upper locking mechanism 4 b disposed within the upper connection kit 3 a comprises a locking bar 410 , a spring 420 , a sleeve 430 , and a turning rod 440 . The sleeve 430 is provided with a upright plate 431 . The two sides of the upright plate 431 can be inserted and fixed within the upright opening 38 of the pivotal joint 32 . One end of the locking bar 410 can be fit into the sleeve 430 . A spring 420 is provided at one end of the sleeve 430 inserted with the locking bar 410 so that the locking bar 410 can be switched horizontally and return back to its original position. A rabbet 411 is provided in the main body of the locking bar 410 for disposing the turning rod 440 .
[0056] As shown in the figure, the turning rod 440 , presented as V-shaped, has a yoke 441 at one end that can be inserted into the rabbet 411 of locking bar 410 , and has a base plate 442 at another end; a downward protruding bump 443 is formed at the lower end of said base plate 442 ; a pivot 444 is formed in the joint of the yoke 441 and base plate 442 so that the turning rod 440 can be embedded into an axial opening 39 of the upper connection kit 3 a through the pivot 444 and the bump 443 can be exposed from the opening 310 (as shown in FIG. 8 ).
[0057] Referring to FIG. 9 , regardless of the first-length connection kit 3 or upper connection kit 3 a , a upward protruding fixing ejection bar 300 is provided at the upper end of the ringlike covering part 31 . The fixing ejection bar 300 is formed with the connection kit 3 ( 3 a ). Since it is formed at upper end of the ringlike covering part 31 , it is not covered by the transverse step portion 5 . Said fixing ejection bar 300 is oriented to the opening 310 of the upper connection kit 3 a.
[0058] During implementation, as shown in FIGS. 10 and 11 , when the control pad 45 is switched toward the center of the stepladder, through the pull rod 44 , it drives the locking bar 42 to withdraw from the through and fixing hole 23 of the side rail section. The upper side rail section 2 a , upper connection kit 3 a , and upper transverse step portion 5 a fall down after the locking bar 42 withdraws from the through and fixing hole 23 . When the upper connection kit 3 a falls down and sticks on the first-length connection kit 3 (as shown in FIG. 11 ), the fixing ejection bar 300 at the upper end of the first-length connection kit 3 enters into the opening 310 of the upper connection kit 3 a while pushing the bump 443 of the turning rod 440 within the upper locking mechanism to rotate the turning rod 440 and then the locking bar 410 is pulled back through the yoke 441 of the turning rod 440 . When the locking bar 410 withdraws from the through and fixing hole of the third-length side rail section, the third-length side rail section, connection kit, and transverse step portion fall down simultaneously, and the fixing ejection bar 300 of the third-length connection kit will be pushed against the fourth-length turning rod, and then the fourth-length side rail section, connection kit, and transverse step portion will fall down; accordingly, once the first-length control pad 45 is pushed, each length of the side rail sections will go down and be folded; also, through the setup of the buffering device 6 and elastic seal ring 62 , each length of the side rail sections can cushion the extension or folding without any noise.
[0059] With the construction described above, the extension ladder in the present invention not only decreases the part cost but also increases the using reliability through the simplified structure. Also, the locking mechanism is hidden in the internal part which can avoid danger of touching the turning rod carelessly during unlocking.
[0060] Referring to FIG. 12 , in another embodiment of the extension ladder in the present invention, an unlocking bock 7 is additionally provided. A partition ejection bar 71 that is equal to the ejection bar is provided at the upper end of the unlocking bock 7 ; a groove for the ejection bar 72 that is equal to the ejection bar is provided at the lower end of the unlocking bock. When the unlocking bock 7 is fit into the upper end of the fixing ejection bar 300 , the fixing ejection bar 300 is also pushed up.
[0061] Referring to FIGS. 13 and 14 , since the unlocking bock 7 can be fit into the upper end of the fixing ejection bar 300 , the turning rod 440 within the upper connection kit can be pushed through the partition ejection bar 71 to unlock, which not only will not impact the operation of the locking mechanism, but also renders a partition space 73 between the upper transverse step portion 5 a and lower transverse step portion 5 during folding. The partition space 73 allows cables or wires to be passed through or allows operators who need to wear gloves in a long time to hold the ladder easily when the extension ladder is used in any specific location.
[0062] Referring to FIG. 15 , in another embodiment of the extension ladder in the present invention, an elastic support set 8 is provided at the lower end of extension ladder 1 , which not only increases the basal area of the extension ladder, enhances the safety, but also provides more applicable locations based on different, uneven ground or step differences, and enhances the reliability.
[0063] Referring to FIGS. 16 , 17 , and 18 , said elastic support set 8 comprises two rail portions 81 , 82 that can be fit in with the side rail section; a step portion 83 is disposed between the two rail portions 81 , 82 ; a pedestal 84 is disposed at the lower end of the rail portions 81 , 82 ; an extension bar 85 is disposed at the upper end of said pedestal 84 . A ball-shaped stand 86 is connected with a pedestal 84 at the lower end of the extension bar 85 so that the extension bar 85 can be rotated arbitrarily; a stable element 87 is disposed at the upper end of the extension bar 85 so that the extension bar 85 contacts with the internal wall of rail portions 81 and 82 through the stable element 87 without swaying. Said pedestal 84 comprises a rubber pad 841 , a middle cover 842 , and a upper cover 843 . The middle cover 842 and upper cover 843 are hooked up with each other and cover the ball-shaped stand 86 so that the extension bar 85 can be adjusted and rotated.
[0064] In addition, a tensile control mechanism 88 is provided in the middle of the extension bar 85 which is formed through that a top inclined spring 882 is provided within a base 881 . The upper end of said top inclined spring 882 is pushed against a one-way snap-fit iron sheet 883 . The upper end of one-way snap-fit iron sheet 883 sticks on an inclined piece 884 ; a hole (not shown in the figure) is disposed at the center of the one-way snap-fit iron sheet 883 and inclined piece 884 so that the extension bar 85 can pass therethrough. Accordingly, when the one-way snap-fit iron sheet 883 is inclined, the extension bar 85 gets stuck through the inclined hole edge so that the extension bar 85 can only be pulled upward and cannot be pulled back, which ensures the safety of using the stepladder. Therefore, with the one-way snap-fit iron sheet 883 , extension bar 85 can adjust the height difference of the ladder foothold.
[0065] A switch 885 is disposed in one end of the one-way snap-fit iron sheet 883 . When the switch 885 is pushed up, the one-way snap-fit iron sheet 883 is pulled back as horizontal. At this time, since the extension bar 85 no longer gets stuck with the hole edge, the extension bar 85 can be pulled back arbitrarily.
[0066] Referring to FIG. 19 , the extension ladder in the present invention is equipped with the locking display function. As shown in the figure, a window frame 323 or 324 is disposed respectively in the two sides of the pivotal joint 32 of connection kit 3 . Two display cards 91 and 92 showing two sections 9 a and 9 b on their external surface respectively are disposed with the window frames 323 and 324 , wherein a transverse bolt 93 is disposed at one end of the first display card 91 ; a transverse dowel hole 94 is disposed at one end of the second display card 92 ; a transverse hole 951 is disposed in the main body of the locking bar 95 so that the first display card 9 passes through the transverse hole 951 with the bolt 93 , and then the second display card 92 is inserted into the dowel hole 94 . A window opening 961 is provided at two sides of the transverse step portion 96 respectively for exposing the first section 9 a or second section 9 b of the display card.
[0067] Accordingly, through observing whether the first section 9 a or second section 9 b is displayed in the window opening 961 , locking of the locking bar can be secured and application safety can be ensured.
[0068] Therefore, referring to FIGS. 20 , 21 A, and 21 B, wherein FIG. 21A is an enlarged view of the part A of the FIG. 20 showing that when the locking bar is inserted into the through and fixing hole of a side rail section, the second section 9 b is displayed in the window opening 961 ; FIG. 21B is an enlarged view of the part B of FIG. 20 showing that after the locking bar is withdrawn from the through and fixing hole of the side rail section, the first section 9 a is exposed in the window opening 961 . Accordingly, whether the locking bar is locked and fixed can be confirmed from the outside of the window opening 961 and the safety can be enhanced.
[0069] Therefore, in the improvement of an extension ladder structure in the present invention, since a fixing ejection bar is disposed at the upper end of the connection kit, an in-protruding encircling ring part is disposed at the upper tube opening of the side rail section, and a out-protruding protruding ring part is disposed at the lower end of the side rail section, which can prevent the side rail sections from departing from each other and enhance the fabrication convenience and controllability. With the setup of the unlocking bock and elastic support set, the applicable scope and reliability is increased.
[0070] As described above, the extension ladder apparatus in the present invention certainly enhances appliance safety, and makes folding and using quick and convenient, which can improve the deficiencies of conventional ladders. Also, the present invention has not yet opened to public, it is then complied with the conditions of allowable patents.
[0071] Although the above-mentioned embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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An extension ladder ( 1 ) comprises a plurality of ladder sections ( 2 ), connection kits ( 3 ) and transverse step beams ( 5 ). Each ladder section is a hollow rail having different caliber, which can be interconnected by telescoping with each other. A snap-fit mechanism is provided between the upper ladder section and the lower ladder section to make them not slip when the extension ladder is extended. The upper end of each ladder section is provided with a connection kit transverse provided. The upper end of the connection kit is provided with a fixed protuberant pin ( 300 ), an inside thereof is provided with a locking mechanism ( 4 b ). The locking mechanism ( 4 b ) is provided with a turning key ( 440 ). An outside of the connection kit is covered by the transverse step beam. When the upper connection kit and other lower connection kit are close to each other, the protuberant pin of the lower connection kit pushes the turning key in the connection kit so that the locking mechanism of the upper connection kit can be unlocked to make the upper ladder sections fall automatically in turn.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and systems for automatically identifying non-labeled, manufactured parts.
2. Background Art
Bar code readers are used extensively in many retail industries, such as hardware stores, at checkout stations to identify tagged items affixed with bar code tags. An item is identified by means of its bar code using a database stored in a host computer. Typically, a description of the item and its price are printed on a hardware store receipt and an ongoing price total is kept as additional items are scanned.
The use of bar code readers has generally been well received by the public, due in part, to the reliability and reduced time spent in the checkout line. However, a reliable system is needed to identify items for which it is undesirable or impractical to attach bar code labels, for example, manufactured bulk parts, such as individual fasteners such as nuts and bolts. Such parts or items are typically not identified and recorded by a bar code reader since such items are typically not labeled with bar codes. Identification of manufactured bulk items is still a task for the checkout operator, who must identify the item and then manually enter an item identification code. Operator identification methods are slow and inefficient because they typically involve a visual comparison of the item with pictures of the items. This time-consuming process can cause bottlenecks at the checkout stations, reducing throughput and making customers unhappy.
U.S. Pat. No. 6,424,745 discloses a method and system for optically recognizing an object from a reference library of known products based on a spectrum of local radius of curvature of the object. A surface portion of an object is illuminated with a pattern of light that permits the extraction of three dimensional coordinates for a set of points on the surface portion of the object. An image data set of the surface portion of the object is then captured with a capture device that is positioned at an angular offset with respect to a source of the light. That is, the combination of the light pattern and the imaging device together generate a two dimensional captured image, from which it is possible to extract the three dimensional coordinates for the set of points on the surface portion of the object. A set of local radii of curvatures are then determined for selected data points in the image data set. A spectrum representing a distribution of the curvatures is then computed for the set of local radii of curvatures. If the data set is for the generation of a library of spectra, it is processed with a dimension reduction analysis to determine a single set of basis functions representing all of the objects and a corresponding set of basis coefficients for each different type of object. If the data set is for an unknown object, then the dimension reduction analysis and the basis functions are applied to the data set to generate an unidentified set of basis coefficients. This latter set is then statically compared with the reference library of spectra to identify the product or at least designate the closest known products.
U.S. Pat. No. 6,457,644 discloses an item checkout device which combines a produce data collector with an optical bar code data collector. The item checkout device includes a housing, a bar code data collector within the housing, and a produce data collector within the housing. In a preferred embodiment, the item checkout device includes an optical bar code data collector including a first housing, a scale within the first housing, a weigh plate on the scale including a first window for allowing scanning light beams from optical bar code data collector to pass and a second window, and a produce data collector within the first housing including a second housing containing an aperture adjacent the second window, a light source for illuminating a produce item on the second window with substantially uniform light, a light separating element for splitting light collected from the produce item into a plurality of different light portions having different wavelengths, a detector for converting energy in the plurality of light portions into a plurality of electrical signals, and control circuitry which digitizes the plurality of electrical signals to produce a digital spectrum from the produce item which contains information to identify the produce item for the purpose of determining its unit price.
U.S. Pat. No. 5,867,265 discloses an optical identification system which includes a light source with a broad wavelength spectrum that is directed on an object to be identified. Suitable optical components, such as, one or more collimating lenses gather light that is reflected from the object and direct this light into a spectrometer. The spectrometer disperses the collimated light using a dispersing element, such as one or more gratings, prisms or a combination of both, onto an array of detectors. The array of detectors may be comprised of a linear diode array or a charge-coupled device (CCD) array which indicates the amount of light at each of a finely-spaced set of wavelengths covering a wide spectral range. The detectors are sensitive over a wavelength region, for example, in the case of silicon detectors from near-infrared plus the visible region, e.g., from 250 nm to 1100 nm. The set of signals from the detectors is read with an analog to digital converter, and transferred to a computer in the form of a spectrum. A set of known spectra determine the reference spectra and the unknown test spectrum is compared with the reference sets. A software program in the computer compares the test spectrum with reference spectra sets utilizing a statistical program. The program takes into account how much the known spectra vary from one another in addition to the average values. A display reads out a list of possible matches in rank order that have a probability of match greater than a predetermined threshold. An operator checks that the first listed item is correct and either accepts the first choice or indicates the correct choice. As an alternative, the system could automatically accept the first choice.
U.S. Pat. No. 6,075,594 discloses a system and method for optically identifying a product from a reference library of known products based on a reflected spectrum of the product. A broad wavelength light source illuminates the product and a spectrometer receives and forms a plurality of finely spaced wavelengths from the reflected spectrum. A detector optically processes the wavelengths to generate signals proportional to an amount of light received at each of the wavelengths. The signals are normalized and pre-processed to form data sets which relates each of the signals to each of the finely spaced wavelengths. This is performed for all of the different products and compiled. A set of basis functions is then generated for all of the different products and a corresponding set of basis coefficients is generated for each of the different products. This information, along with an electronic label for each product, is stored to form the reference library. When identifying an unknown product, the system generates a set of basis coefficients for the product to be identified. This latter set is statically compared against the reference library to identify the corresponding set of basis coefficients most closely matching the unknown set of basis coefficients.
U.S. Pat. No. 7,044,370 discloses a method and system for self-checkout of items from a retail or non-retail establishment. The system verifies security by comparing a measured physical characteristic of an item with the stored security characteristic for that item and determining if the measured physical characteristic is within an operator-modifiable tolerance range. The operator-modifiable tolerance range is different for different items in the store. Moreover, a stored security characteristic of an item can be updated automatically. In addition, the system includes a dynamic-weight scale that reports a measured weight before the scale settles.
U.S. Pat. No. 6,598,791 discloses a self-checkout system for a retail establishment that allows a customer to checkout multiple items having respective identification codes. The system includes a computer having memory with a buffer, an identification code reader coupled to the computer for determining the identification of the items by the identification codes, a security verification mechanism coupled to the computer for verifying that the items actually being checked out from the retail establishment are the same as those identified by the identification code reader. The computer is adapted to store identification information of multiple items obtained by the identification code reader in the buffer before verifying that the items actually being checked out from the retail establishment are the same as those identified by the identification code reader.
U.S. Pat. No. 5,608,530 discloses a laser for producing a beam of radiation which is then refined in cross-sectional dimension by use of plano-cylindrical lenses. The refined beam of radiation falls incident on a part to be measured. The unobstructed portion of the beam is then bifurcated by a pair of reflective surfaces which produce non-parallel radiating beams; each beam comprised of the unobstructed portion of radiation which has passed radially opposed halves of the part. The magnitude of radiation present in each non-parallel radiating beam is then measured.
U.S. Pat. No. 4,831,251 discloses an optical device for discriminating threaded workpiece by the handedness by their screw thread profiles. The device present a pair of light beams which pass generally tangent to the workpiece at angularly displaced positions. The light beams are inclined to follow the helix direction of a given handedness of a workpiece. Upon axial advancement of a workpiece through the device, a chopped output from the photodetectors indicates that the handedness of the threads matches the inclination of the light beams. The oppositely threaded workpiece, however, provides a generally constant DC output. With appropriate signal processing electronics, an automatic system for discriminating workpieces by thread handedness is provided.
U.S. Pat. No. 5,383,021 discloses a non-contact inspection system capable of evaluating spatial form parameters of a workpiece to provide inspection of parts in production. The system causes parts to be sequentially loaded onto an inclined track where they pass through a test section. The test section includes a length detection array for measuring the length of the workpiece, which includes a source generating a sheet of light oriented in the longitudinal direction of the workpiece. The profile of the parts are evaluated by one or more light sources also creating a sheet of light oriented transversed to the longitudinal axis of the parts. Single channel photodetectors are provided for each of the sources which provides an analog output of the extent to which each sheet of light is occluded by the part. These outputs are analyzed through appropriate signal processing hardware and software to generate length and profile data related to the workpiece geometry.
U.S. Pat. No. 5,568,263 discloses a non-contact inspection system capable of evaluating spatial form parameters of a workpiece to provide inspection of parts in production. The system causes parts to be sequentially loaded onto an incline track where they pass through a test section. The test section includes a length detection array for measuring the length of the workpiece, which includes a source generating a sheet of light oriented in the longitudinal direction of the workpiece. The profile of the parts are evaluated by one or more light sources also creating a sheet of light oriented transverse to the longitudinal axis of the parts. First and second pairs of single channel photodetectors are provided for each of the light sources which provides a pair of analog outputs of the extent to which each sheet of light is occluded by the part, as well as an ability to eliminate noise or scintillation caused by a point source of light, for example with a laser light source. These outputs are analyzed through appropriate signal processing hardware and software to generate length and profile data related to the workpiece geometry.
U.S. Patent Application Publication No. 2005/0174567 discloses a system to determine the presence of cracks in parts. The presence of cracks is determined through the use of an imaging device and illumination source. The part is moved along a track where it is sensed by a position sensor to initiate the inspection. The illumination source protects a sheet of light onto the part to be inspected. The line formed by the intersection of the sheet of light and the part is focused onto the imaging device. The imaging device creates a digital image which is analyzed to determine if cracks are present on the part.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and system for automatically identifying non-labeled, manufactured parts in an accurate, reliable and timely fashion.
In carrying out the above object and other objects of the present invention, a method for automatically identifying non-labeled, manufactured parts is provided. The method includes storing templates of a plurality of known good, manufactured parts. Each of the templates includes a part profile and a set of features. Each of the features includes a range of acceptable values, and each of the templates has a part identification code associated therewith. The method further includes optically measuring a profile and features of a part to be purchased, and comparing the profile and the features of the part to be purchased with the profile and corresponding features of each of the stored templates to identify a template which most closely matches the profile and features of the part to be purchased. The method further includes generating and transmitting an identification signal representing the part identification code for the part associated with the most closely matched template.
The step of optically measuring may include the steps of: a) projecting a beam of radiant energy; b) translating the part to be purchased so that the translating part partially obstructs the beam to obtain at least one unobstructed portion of the beam of radiant energy; and c) imaging the at least one unobstructed portion of the beam of radiant energy to obtain a first set of electrical signals.
The method may further include determining a velocity of the translating part, and processing the first set of electrical signals with the velocity to obtain the profile and features of the part to be purchased.
The part to be purchased may be at least partially conductive or semiconductive, and a feature of at least one of the templates may include an eddy current signature. The method may further include the steps of inducing an eddy current in the translating part, sensing the induced eddy current and comparing the eddy current signature with the sensed eddy current.
The step of translating may include the steps of providing an inclined track and dropping the part to be purchased onto the inclined track so that the part slides down the inclined track by the force of gravity.
The step of determining may include the steps of: generating and sensing a series of beams of radiant energy at predetermined spaced positions along a path taken by the translating part so that the translating part sequentially obstructs each of the series of beams.
The part to be purchased may partially obstruct the beam of radiant energy to obtain first and second unobstructed portions, and the first and second unobstructed portions of the beam of radiant energy may be imaged to obtain the first set of electrical signals.
The first and second unobstructed portions of the beam of radiant energy may be imaged in separate first and second image planes.
Each of the first and second unobstructed portions of the beam of radiant energy may contain a magnitude of radiation which is representative of a respective geometric dimension of the part to be purchased.
The part to be purchased may be a fastener.
The fastener may have threads, and at least one of the templates may include at least one feature related to threads.
The fastener may be externally or internally threaded.
The part may be a flat part, or a cylindrical or near-cylindrical part.
Still further in carrying out the above object and other objects of the present invention, a system for automatically identifying non-labeled, manufactured parts is provided. The system includes an electronic storage device to store templates of a plurality of known good, manufactured parts. Each of the templates includes a part profile and a set of features. Each of the features includes a range of acceptable values. Each of the templates has a part identification code associated therewith. A first subsystem optically measures a profile and features of a part to be purchased. The system further includes a processor operable to compare the profile and the features of the part to be purchased with the profile and corresponding features of each of the stored templates to identify a template which most closely matches the profile and features of the part to be purchased and to generate and transmit an identification signal representing the part identification code for the part associated with the most closely matched template.
The first subsystem may include: a) a projector to project a beam of radiant energy; b) a feed mechanism to translate the part to be purchased so that the translating part partially obstructs the beam to obtain at least one unobstructed portion of the beam of radiant energy; and c) an imager to image the at least one unobstructed portion of the beam of radiant energy to obtain a first set of electrical signals.
The system may further include a second subsystem to determine a velocity of the translating part. The processor may be further operable to process the first set of electrical signals with the velocity to obtain the profile and features of the part to be purchased.
The part to be purchased may be at least partially conductive or semiconductive. A feature of at least one of the templates may include an eddy current signature, and the system may further include an eddy current sensor to induce an eddy current in the translating part and to sense the induced eddy current. The processor may also compare the eddy current signature with the sensed eddy current.
The feed mechanism may include a track inclined so that the part slides down the inclined track by the force of gravity.
The second subsystem may include a plurality of sensors to generate and sense a series of beams of radiant energy at predetermined spaced positions along a path taken by the translating part so that the translating part sequentially obstructs each of the series of beams.
The part to be purchased may partially obstruct the beam of radiant energy to obtain first and second unobstructed portions. The first and second unobstructed portions of the beam of radiant energy may be imaged to obtain the first set of electrical signals.
The first and second unobstructed portions of the beam of radiant energy may be imaged in separate first and second image planes.
Each of the first and second unobstructed portions of the beam of radiant energy may contain a magnitude of radiation which is representative of a respective geometric dimension of the part to be purchased.
The part to be purchased may be a fastener.
The fastener may have threads, and at least one of the templates may include at least one feature related to threads.
The fastener may be externally threaded, or may be internally threaded.
The part may be a flat part, or may be a cylindrical or near-cylindrical part.
Yet still further in carrying out the above object and other objects of the present invention, a system for automatically identifying non-labeled, manufactured parts is provided. The system includes means for storing templates of a plurality of known good, manufactured parts. Each of the templates includes a part profile and a set of features. Each of the features includes a range of acceptable values, and each of the templates has a part identification code associated therewith. The system further includes means for optically measuring a profile and features of a part to be purchased, and means for comparing the profile and the features of the part to be purchased with the profile and corresponding features of each of the stored templates to identify a template which most closely matches the profile and features of the part to be purchased. The system still further includes means for generating and transmitting an identification signal representing the part identification code for the part associated with the most closely matched template.
The means for optically measuring may include: a) means for projecting a beam of radiant energy; b) means for translating the part to be purchased so that the translating part partially obstructs the beam to obtain at least one unobstructed portion of the beam of radiant energy; and c) means for imaging the at least one unobstructed portion of the beam of radiant energy to obtain a first set of electrical signals.
The system may further include means for determining a velocity of the translating part; and means for processing the first set of electrical signals with the velocity to obtain the profile and features of the part to be purchased.
The part to be purchased may be at least partially conductive or semiconductive. A feature of at least one of the templates may include an eddy current signature. The system may further include means for inducing an eddy current in the translating part and sensing the induced eddy current. The means for comparing may also compare the eddy current signature with the sensed eddy current.
The means for translating may include a track inclined so that the part slides down the inclined track by the force of gravity.
The means for determining may include means for generating and sensing a series of beams of radiant energy at predetermined spaced positions along a path taken by the translating part so that the translating part sequentially obstructs each of the series of beams.
The part to be purchased may partially obstruct the beam of radiant energy to obtain first and second unobstructed portions. The first and second unobstructed portions of the beam of radiant energy may be imaged to obtain the first set of electrical signals.
The first and second unobstructed portions of the beam of radiant energy may be imaged in separate first and second image planes.
Each of the first and second unobstructed portions of the beam of radiant energy may contain a magnitude of radiation which is representative of a respective geometric dimension of the part to be purchased.
The part to be purchased may be a fastener.
The fastener may have threads, and at least one of the templates may include at least one feature related to threads.
The fastener may be externally threaded, or may be internally threaded.
The part may be a flat part, or may be a cylindrical or near-cylindrical part.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of one embodiment of a system of the present invention together with a plurality of non-labeled, manufactured parts capable of being automatically identified with the system;
FIG. 2 is a perspective schematic view, partially broken away, of a part feed mechanism supported within a system constructed in accordance with an embodiment of the present invention wherein the system includes an eddy current sensor including eddy current coils;
FIG. 3 is an exploded perspective schematic view of a portion of a system constructed in accordance with an embodiment of the present invention and illustrating the optical part measurement sensors and a trigger which generate corresponding electrical signals which are subsequently processed;
FIG. 4 is a side schematic view of one embodiment of an optical subsystem of the system of the present invention;
FIG. 5 is a portion of a screen shot of a display which illustrates the types of part features which can be optically measured using the method and system of the present invention in order to identify the part to be purchased;
FIG. 6 is a screen shot on the screen of a display which illustrates a template including the profile of a Allen bolt having a number of features and a UPC (i.e., Universal Product Code);
FIG. 7 is a generalized block diagram of hardware constructed in accordance with one embodiment of the system of the present invention;
FIG. 8 is a more detailed block diagram of the hardware of FIG. 7 ;
FIG. 9 is a block diagram which illustrates the flow of data utilizing one embodiment of a method of the present invention; and
FIG. 10 is a flock diagram flow chart illustrating the sequence of some of the steps of one embodiment of the method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In general, one embodiment of the method and system of the present invention utilizes non-contact optical inspection technologies to map profiles of small cylindrical parts. The embodiment has a part setup procedure for a user to capture an image of a known dimensioned part and define a set of features with acceptable range of limit values for them. The part profile and features are referred to as the part template. During part ID mode, the profile of each inspected part is captured and its features are compared to their limit values. If any feature of a part is determined to be outside its range of limits, then it is not identified.
The preferred method for capturing a part profile is to pass the part through a directional plane of light that is sensed or measured by a power meter or detector. The uninterrupted light is of a know power. The dimension, usually referred to as the diameter, of a part perpendicular to the direction of light at the point it intersects the light is determined by the power meter, which would sense less light. The diameter at each point on the part along the direction of travel is measured.
Referring to FIG. 1 , there is illustrated one embodiment of a system, generally indicated at 20 , for automatically identifying non-labeled, manufactured parts. Such parts may include, as illustrated in FIG. 1 , fasteners, whether threaded or not, such as nuts, bolts, nails. Such parts may include flat parts such as washers or cylindrical or near-cylindrical (i.e., have a small cosine error) parts such as plastic tubular members. The parts may be at least partially conductive, semiconductive, or conductive. The parts may be plated or non-plated, heat-treated or non-heat-treated, or include seams. Typically, the parts may have a diameter range of 2 mm to 35 mm and a length range of 10 mm to 150 mm.
Referring to FIGS. 1 and 2 , the system 20 includes a feed mechanism or subsystem, generally indicated at 22 , supposed within a housing 23 of the system 20 . The feed mechanism 22 includes a V-shaped track 24 , the sides of which are preferably aligned with respect to each other at a angle of approximately 120°.
Referring now to FIG. 4 , an optical subsystem, generally indicated at 26 , is now described. Generally, the subsystem 26 includes a laser 28 for producing a beam of radiation which is then shaped in cross-sectional dimension by use of plano-cylindrical lenses 30 and 32 . The lens 32 focuses the beam 33 to a focal point which forms a line 31 . The refined beam 33 of radiation falls incident on a part 34 to be measured. The unobstructed portions 36 and 38 of the beam 33 are then redirected by a pair of reflective surfaces 40 and 42 of a prism 44 producing radiating beams 46 and 48 ; each beam 46 and 48 comprises the unobstructed portion of radiation which has passed radially opposed halves of the part 34 . The magnitude of radiation present in each radiating beam 46 and 48 is then measured by optical measurement sensors or optical or photo detectors 50 and 52 after passing through plano-cylindrical lenses 54 and 56 , respectively, and negative concave lenses 58 and 60 , respectively. The magnitude of radiation measured at sensing elements 60 and 62 of the detectors 50 and 52 , respectively, is proportional to a dimensional measurement of the part 34 . The diameter at each point on the part 34 along its direction of travel is measured. The photo detectors 50 and 52 provide diameter laser signals as shown in FIG. 8 . The optical system 26 is described in greater detail in U.S. Pat. No. 5,608,530.
Preferably, instead of the prism 44 , a pair of offset mirror elements may provide a pair of reflective surfaces to direct the beams 46 and 48 side-by-side to a pair of side-by-side photo detectors.
Referring to FIG. 3 , the preferred optical subsystem 26 of FIG. 4 is incorporated in upper and lower portions of the system 20 to generate a sheet 64 of light through which a part (not shown in FIG. 3 ) translated by means of the inclined track (not shown in FIG. 3 ) 24 of the feed mechanism 22 . The sheet 64 of light is generated in response to a trigger signal or pulse emitted by a central unit or hardware trigger 65 (i.e., FIG. 8 ) when a pencil light beam (not shown) in the track 24 is blocked.
Also shown in FIG. 3 are a series of eight parallel beams of light 66 which are generated by laser diode assemblies (only two of which is shown at 68 ) at predetermined spaced positions below the path taken by the translating part 34 along the track 24 so that the translating part sequentially obstructs each of the series of beams. The beams 66 extend through small holes formed in the track and strike a corresponding series of spaced photo detectors 70 supported at an upper portion of the system 20 . In this way, a velocity of translating part is estimated based on the time at which the beams 66 are either detected or not detected by the photo detectors 70 as indicated by the velocity laser signals in FIG. 8 which are received by a velocity gauge receiver and subsequently processed. Typically, once the velocity of the translating part is determined, the velocity is processed with the diameter laser signals to obtain a profile and features of the part 34 as will be described in greater detail hereinbelow.
Referring again to FIG. 2 , there is illustrated an eddy current sensor 72 which includes coils 74 (i.e., FIG. 8 ) which not only induce an eddy current in the translating part 34 , but also sense the induced eddy current to provide a signal to an eddy current module (i.e., FIG. 8 ), which represents the amount of induced eddy current.
Again, pencil light beams in the V-slide monitor the part's progress as it falls down the track 24 or slide. Each pencil light beam is associated with a small control unit or hardware trigger that produces an electrical pulse when the light is blocked; the pulse is referred to as a “trigger.” Two of these are typically associated with the eddy current hardware. For eddy current, these essentially provide a “get ready”, then a “get set” signal to the hardware than controls the induced eddy current.
Referring now to FIGS. 7 and 8 , the hardware of the system 20 includes four main subsystems. Part measurement sensors and triggers include velocity gauge lasers and sensors, diameter gauge lasers and sensors, hardware triggers that monitor the passage of the part down the V-slide, and eddy current measurement coils. Hardware management and sensor electronics include a SLIC hardware manager and a number of modules required to convert the measurement signals to information a control computer can utilize. The control computer performs all signal processing, manages the user interface, and has a communication interface to a cash register.
Referring now to FIG. 9 , the data and signal processing system described therein illustrates how the system processes sensor data and discovers the ID of the part presented to the system. Using calibration data, sensor data is transformed to a description of the outline of the part, specified in calibrated physical coordinates. Feature processing extracts values for each feature contained in the entire part template data set. Match metric processing identifies the best match to the sensor data among the part templates. ID generation evaluates the best match; if the match is good enough, the part is said to be identified, otherwise the part is not identified. After ID generation, a message is sent to the cash register, containing the part ID or a “not matched” indication.
When a new part is added to the system 20 , a file called a “template” is created. The template file contains information about the part that is used to identify it. The template is set up so that any part of the given type will match the template, and any part not of the given type will not match.
When the user drops a part to be purchased on the machine track 24 , as illustrated in FIG. 10 , the software acquires data containing the profile and eddy signature of the part. The software then checks all the templates in the list to find a match. If the part matches one of the templates, then the part is identified. If none of the templates match, the part is not identified.
In general, when setting up a new part, the user chooses “features” of the part to be measured. The measurements of the features will distinguish the new part from the other parts in the system. The types of features include total length, internal length, diameter, thread, taper, and eddy current signature. For most features, the user chooses a region of the part where the measurement will be made, a nominal value of the measurement (the value the part should have if it's the right part), and plus and minus tolerances which determine if the measurement is close enough to match the part. For some features, such as total length and eddy, the measurement region is the whole part. Also, for eddy current the user chooses a rectangle on the eddy screen of a display instead of a nominal value and tolerances. If the eddy signature hits the rectangle, then the part is a match.
The user chooses which features are needed to distinguish the new part. For a wirenut, for example, the user would typically add a total length feature and a taper feature. A bolt may need total length, thread, and one or two diameters. If it is necessary to distinguish the type of material or coating to distinguish a bolt from another bolt, the user would add the eddy feature.
When all of the necessary features have been set up in a template, the user saves the template. This adds it to the list of templates to check when a part is dropped during the part identification operation, as previously described.
More particularly, in creating a template a gold or master part with known good dimensions is dropped on the inclined track so it slides down the track after the particular part is named. After the part has traveled the length of the track, an image of the part is displayed on a screen, as generally shown in the screen shot of FIG. 6 .
After a good image of the part is obtained, features are added to the template as previously mentioned. For example, when adding an internal length, as noted in the second display block of FIG. 5 , points are determined on the part when one wishes to measure the internal length (i.e., here the length of the head of the bolt). One can add multiple internal lengths for each part. Internal lengths can be used to measure features like: thread length, shoulder length, head height, under the head to the start of a part, and any length measurement needed inside of a part.
Such predefined points are also useful for other template features like diameters (i.e., third block of FIG. 5 ) and tapers (i.e., fifth block of FIG. 5 ). Such predefined points are useful when looking for rising and falling edges of the part as well as when looking for minimum and maximum diameters of the part.
The diameter feature is used to measure diameters around a part. Multiple diameters can be added for each part as shown in the third block. One can select minimum and maximum diameters for a selected area (or a small groove within a selected area) or one can average all the diameters in the area selected.
With respect to taper features, tapers are used to measure tapered angles on a part. Multiple tapers can be added for each part.
The external/overall length feature is automatically added to the list of features once the part has been scanned (i.e., travels down the track). The length is measured by the velocity sensors and is determined by the start and end predefined points.
With respect to the thread features (i.e., block 4 of FIG. 5 ), the tolerances on the following thread features can change: thread count, thread pitch, pitch diameter, functional size, lead deviation, minor diameter, and major diameter.
With respect to the UPC codes, the designated UPC code can be entered on the touch screen to identify the part corresponding to a particular template as shown in FIG. 6 , which also shows various features of an Allen bolt.
With respect to eddy current (i.e., the rightmost box of FIG. 5 ), a frequency parameter is initially set up for a particular part. A relatively low frequency such as 1 KHz may be used to check for material and a relatively high frequency such as 50 KHz may be used to check for plating of a part. During the generation of a template for eddy current, a known good part is sent down the track to get a signature of the part on the screen. After obtaining a signature, one may have to adjust the parameters of the frequencies and the gains while testing a good part, until a good image is obtained on a screen of a display. A good image should have a defined area, like a loop, that will have some space inside it. After establishing the eddy current signature of a good part, the area of the signature one wants to inspect may be highlighted.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
For example, the system could include multiple sensors (lasers) to provide multiple inspections around a part. A laser head oriented to “look” down at the bottom track where flat parts like washers and nuts would ride would improve the inspection and identification of the part.
The axis of the “Vee” track is preferably canted a few degrees to allow flat parts to ride on the bottom track.
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A method and system are provided for automatically identifying non-labeled, manufactured parts. The system includes an electronic storage device to store templates of a plurality of known good, manufactured parts. Each of the templates includes a part profile and a set of features. Each of the features includes a range of acceptable values. Each of the templates has a part identification code associated therewith. A first subsystem optically measures a profile and features of a part to be purchased. The system further includes a processor operable to compare the profile and the features of the part to be purchased with the profile and corresponding features of each of the stored templates to identify a template which most closely matches the profile and features of the part to be purchased and to generate and transmit an identification signal representing the part identification code for the part associated with the most closely matched template.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to, and the benefit of, Japan Patent Application No. 2007-104666, filed on 12 Apr. 2007, in the Japan Patent Office, the disclosure of which is incorporated herein by reference in its entirety.
FIELD
[0002] The present invention relates to electronic devices for surface mount, more particularly to electronic devices in which short-circuiting by solder is prevented when the devices are mounted on a circuit board or the like.
DESCRIPTION OF THE RELATED ART
[0003] Crystal devices are widely known for use as frequency-controlling elements such as crystal units, oscillators, and filters. Crystal devices are mounted on various types of circuit boards of electronic devices including, but not limited to, communication devices. In recent years, crystal devices for surface mount have been developed for mounting on circuit boards with other electronic devices, such as resistors and capacitors. In general, the electronic devices are mounted, using a surface-mount machine, on the circuit board to which solder paste has been applied. Then, the board on which the electronic devices have been placed is conveyed through a reflow furnace to achieve soldering of the electronic devices to the board.
[0004] In many instances the electronic devices must be closely arranged on the circuit board to satisfy current demands of high integration and miniaturization. Consequently, pads (corresponding to respective external terminals) for the electronic devices are situated closely together on the circuit board. As miniaturization of electronic devices for surface mount has progressed, the distances between external terminals on the electronic devices have narrowed, requiring corresponding reductions of distances between external terminals on the board. Consequently, when soldering the electronic devices on the circuit board, solder tends to overflow between external terminals and cause short-circuits. Even in situations in which short-circuits do not form between individual external terminals, solder overflow may become ball-shaped and thus adversely affect other regions of the mount board.
[0005] FIG. 7 shows a piezoelectric oscillator 200 , having a base board 210 , mounted on a circuit board PB. Specifically, the circuit board PB includes a pad 115 , and solder paste SOL has been applied to the pad 115 . When the piezoelectric oscillator 200 enters a reflow furnace after being placed in a state in which a predetermined amount of solder SOL has been applied, a solder ball is formed between the base board 210 and the circuit board PB. Thus, short-circuiting may be produced between the external terminals 215 .
[0006] If a somewhat small amount of solder paste is applied, the desired electrical connection between the external terminal 215 and the pad 115 may be insufficient. It is also difficult to detect whether or not connections between the electronic devices and the circuit board are satisfactory after performing solder reflow. Furthermore, if a connection fault should arise between an electronic device and the circuit board, the faulty connection state between the electronic device and wiring on the board may not be readily detected, which results in decreased product yield.
SUMMARY
[0007] To address the problems described above, an object of the present invention is to provide electronic devices for surface mount that prevent solder from overflowing between external terminals of the electronic device or between pads on a circuit board.
[0008] An electronic device for surface mount according to the first aspect comprises a base board made from an insulating material. An embodiment of the device includes at least one external terminal for surface mount on an outer surface. A groove is formed around the external terminal on a surface to be mounted on the printed circuit board. With this embodiment, even when solder is applied to a circuit board in a somewhat large amount during surface mounting, any over-flowed solder enters the groove. Hence, short-circuiting between external terminals is much reduced.
[0009] A base board on the electronic device for surface mount according to the second aspect comprises a resin board made of a thermoset resin. The groove is formed by thermal or mechanical processing. By making the base board on the electronic device as a thermoset resin board, the groove can be formed by thermal processing, e.g., laser processing. If mechanical processing is used, the groove can be formed by drilling or routing, for example.
[0010] A base board on the electronic device for surface mount according to the third aspect comprises a ceramic board. The groove is formed by embossing or stamping, for example. The external terminals can be printed using metallized ink. By making the base board on the electronic device of ceramic, the groove may be formed by embossing or stamping before performing calcination, followed by metallization to form the external terminals.
[0011] With an electronic device for surface mount according to the fourth aspect, the depth of the groove is from 0.1 mm to 80% of the thickness of the base board. By staying within this range, solder overflow is satisfactorily arrested. If the groove depth exceeds 80% of the thickness of the base board, the base board becomes too weak for adequate durability.
[0012] With an electronic device for surface mount according to the fifth aspect, the width of the groove is from 0.1 mm to 2.0 mm. By staying within this range, solder overflow is satisfactorily arrested.
[0013] The electronic devices can include crystal oscillators and crystal units. Crystal oscillators are categorized as large-sized among electronic devices. Consequently, a rather large amount of solder is applied to the circuit board. The present invention is especially advantageous for this application.
[0014] Electronic devices for surface mount according to the present invention advantageously prevent solder from overflowing between external terminals of the electronic device or between corresponding pads on a circuit board to which the electronic devices are mounted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional view of an exemplary surface-mount piezoelectric oscillator 100 .
[0016] FIGS. 2A and 2B are elevational and plan views of a base board with external terminals.
[0017] FIGS. 3A and 3B are elevational views of a piezoelectric oscillator being mounted on a circuit board.
[0018] FIGS. 4A , 4 B, and 4 C are perspective, elevational, and plan views, respectively, of a crystal oscillator.
[0019] FIGS. 5A-5D depict exemplary steps in a method for manufacturing a ceramic layer for use a bottom layer.
[0020] FIGS. 6A-6D depict representative cross-sectional shapes of grooves.
[0021] FIG. 7 is a side view of a conventional piezoelectric oscillator mounted on a circuit board.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The invention is described in connection with representative embodiments, with reference to the drawings.
Construction of Piezoelectric Oscillator
[0023] FIG. 1 is a cross-sectional view of an embodiment of a surface-mounted, high-stability piezoelectric oscillator 100 of the temperature-controlled type (hereinafter referred to as a “piezoelectric oscillator”). The piezoelectric oscillator 100 comprises a base printed circuit board 10 (called a “base board”) and a sub printed circuit board 40 . The base board 10 is made of an insulating material. On the sub printed circuit board 40 are mounted a temperature-control circuit and/or electronic components 31 for an oscillation circuit. Also mounted to the sub printed board 40 is a crystal-vibrating 32 affixed using conductive adhesive 21 . On the under-surface of the base board 10 , external terminals 15 are arranged in multiple (e.g., four or six) places. The external terminals facilitate mounting of the piezoelectric oscillator 100 on the surface of a circuit board PB (refer to FIG. 3 ). To visually observe a meniscus state of soldering after surface-mounting, the external terminals 15 can be electrically connected with the electronic component 31 or the crystal-unit 32 by plated wiring or by lead wires on the surface of the base board 10 .
[0024] Also mounted to the base board 10 are first ends of respective metal supports 50 made of brass or the like. The first ends are inserted in recesses 11 and affixed using conductive adhesive 21 . Opposing second ends of the metal support 50 are affixed to the sub printed circuit board 40 using conductive adhesive 21 . The entire assembly is covered with a metal case 48 so as to seal the two-tiered base board 10 and sub printed circuit board 40 . The piezoelectric oscillator 100 having such construction generally has a size from approximately 3 mm square to approximately 50 mm square.
[0025] FIGS. 2A-2B depict the base board 10 and external terminal 15 . FIG. 2A is an enlarged view showing the metal support 50 affixed to the base board 10 , and also showing an external terminal 15 . FIG. 2B shows the under-surface of the base board 10 .
[0026] As shown in FIG. 2A , the metal support 50 includes a flange 51 and a shaft 54 . The shaft 54 has a shank 52 extending from the flange 51 . The diameter of the shaft 54 is approximately 0.03 mm to approximately 1 mm, and the diameter of the flange 51 is approximately 0.04 mm to approximately 3 mm. The flange 51 may have a diameter of approximately twice the diameter of the shaft 54 .
[0027] The recess 11 is formed in the base board 10 such that the shank 52 may be inserted therein. The base board 10 is made of a glass-epoxy laminate or other insulating material. The thickness of the base board 10 is approximately 0.6 mm to approximately 3 mm, and the depth of the recess 11 is approximately 90% to approximately 30% of the thickness of the base board 10 . Alternatively, the base board 10 can be made of an insulating material other than glass-epoxy laminate, such as a thermoset resin for glass cloth or glass non-woven fabric base material, an epoxy-resin laminate, a composite laminate, a paper-base epoxy-resin laminate, or a paper-base phenolic resin laminate. Recess or groove processing may be easily applied to these various materials by laser processing, drilling, routing, or the like.
[0028] The diameter of the recess 11 desirably is smaller than the diameter of the flange 51 , and equal to or larger than the diameter of the shank 52 . The recess 11 can be formed in the base board 10 using a flat router in the edge. Copper plating 12 is applied around the recess 11 . The external terminal 15 and the copper plating 12 are electrically connected to each other. The flange 51 of the metal support 50 and the copper plating 12 are affixed using the conductive adhesive 21 .
[0029] The groove 13 extends at least part way around the external terminal 15 . In this regard, the groove 13 a is formed only in the under-surface of the base board 10 destined to be surface mounted on the circuit board PB (refer to FIG. 3 ). The groove 13 a does not extend up the side surface in this embodiment. The groove 13 is configured to facilitate visual observation of a meniscus state of solder on the external terminal 15 from the side surface of the piezoelectric oscillator 100 .
[0030] The groove 13 b is formed entirely in the under-surface of the circuit board PB because processing is easily applied to such end. The depth of the grooves 13 ( 13 a and 13 b ) ranges from 0.1 mm to 80% of the thickness of the base board 10 . The width of the groove 13 is 0.1 mm to 2.0 mm. With these combinations of depth and width of the groove 13 , solder overflow is suppressed in the groove 13 , especially considering the size of the surface-mount piezoelectric oscillator 100 . (Solder overflow is still dependent on the amount of solder SOL applied to the circuit board PB, but this variable can be controlled.) In this embodiment, solder overflow is suppressed by flow of excess solder into the groove 13 a or into the groove 13 b, or into both grooves.
Mounting Piezoelectric Oscillator on Circuit Board
[0031] FIGS. 3A-3B show a piezoelectric oscillator 100 being mounted on the circuit board PB. FIG. 3A is a side view of the piezoelectric oscillator 100 before mounting, and FIG. 3B is a side view of the piezoelectric oscillator 100 after mounting. In FIG. 3A pads 115 are formed on a circuit board PB on which an electronic device or the like is mounted. The pads 115 form respective parts of a circuit. Solder SOL is applied to the pads 115 by application of a solder paste followed by passage through a reflow furnace of infrared type or hot-air type (not shown).
[0032] Solder is usually applied to the pads 115 at a predetermined thickness by application of solder paste SOL using a squeegee (not shown) that urges the paste through a perforated metal mask made from stainless steel (not shown). Then, the piezoelectric oscillator 100 is mounted to regions in which the solder SOL has been applied. The mounting of the piezoelectric oscillator 100 is usually performed by a numerically controlled (NC) surface-mounting machine.
[0033] As shown in FIG. 3B , during mounting of the piezoelectric oscillator 100 , superfluous solder SOL may enter the groove 13 . This flow into the groove prevents formation of solder balls or the like even if a somewhat excessive amount of the solder paste is transferred to the pads 115 . A solder resist could be formed between the external terminals 15 to avoid generating short-circuits between the external terminals. However, with the depicted embodiment, the need for solder resist is eliminated because the grooves accommodate the excess solder.
[0034] The shape of the external terminal 15 can be similar to conventional shapes. The external terminals 15 on the under-surface of the base board 10 can extend up the side surfaces of the base board 10 . This configuration allows visual observations of a meniscus state of soldering.
Construction of Crystal Oscillator
[0035] A crystal oscillator 150 is now described with reference to FIGS. 4A-4C . FIG. 4A is an overall perspective view; FIG. 4B is a cross-sectional view; and FIG. 4C is a top view with the metal lid 61 removed. The crystal oscillator 150 is a surface-mount type, comprising an insulating ceramic package 60 and a metal lid 61 that covers the package. The metal lid 61 desirably is made of Kovar (iron (Fe)/nickel (Ni)/cobalt (Co) alloy). The ceramic package 60 comprises a bottom ceramic layer 60 a, a wall ceramic layer 60 b, and seat ceramic layer 60 c . These layers are punched from green sheets formed from a slurry containing ceramic powder including alumina as a main material, a binder, and the like. Instead of using ceramic powder containing alumina as the main ingredient to form the material of the ceramic package 60 , any of various other materials can be used such as glass ceramic, zero X-Y shrinkage glass ceramic substrate, aluminum nitride, mullite, or the like. As understood from FIG. 4B , the package 60 constructed from the ceramic layers 60 a - 60 c forms a cavity. The electronic component(s) 31 and/or tuning-fork type crystal-vibrating piece 33 is mounted in the cavity.
[0036] Copper plating 12 , electrically connected with the electronic component(s) 31 , is formed in a portion of the top surface of the seat ceramic layer 60 c . At least two external terminals 15 , formed in the lower surface of the ceramic package 60 , are mounted on the surfaces of the pads 115 of the circuit board PB. The copper plating 12 connects to the external terminals 15 . A metallized layer is provided on the upper surface of the wall ceramic layer 60 b . A sealing material 39 , made from a low-temperature-brazing filler metal, is formed on the metallized layer for bonding the metal lid 61 . The wall ceramic layer 60 b and the metal lid 61 are welded together by the sealing material 39 .
[0037] The tuning-fork type crystal-vibrating piece 33 has, in its proximal portion, an adhesion region intended to be electrically connected using conductive adhesive 37 . Specifically, copper plating 12 , electrically connected with an external electrode, is formed on the seat ceramic layer 60 c, and the proximal end of the tuning-fork type crystal-vibrating piece 33 is bonded to the seat ceramic layer 60 c using the conductive adhesive 37 . As affixed, the crystal-vibrating piece extends parallel to the bottom ceramic layer 60 a and produces a predetermined vibration.
[0038] As disclosed in FIGS. 4A-4C , a groove 13 is formed around the external terminals 15 of the crystal oscillator 150 . Consequently, when mounting the crystal oscillator 150 on the circuit board PB, any superfluous solder SOL flows into the groove 13 . Hence, even if an unintended larger amount of solder paste is applied to the pads 115 (e.g., using a squeegee), a solder ball or the like is not formed, and short-circuits are avoided.
Manufacture of Bottom Ceramic Layer
[0039] FIGS. 5A-5D show a method for manufacturing the ceramic package 60 , specifically the bottom ceramic layer 60 a . FIG. 5A shows a first green sheet 60 a 1 made from alumina. The lattice-shaped broken lines 69 denote expected partition lines. In this example, a portion of the first green sheet enclosed by the parting lines 69 is a rectangle of 5 mm by 7 mm. To form the groove 13 , as shown in FIG. 5A , rectangular through-holes 18 are formed in the first green sheet 60 a 1 along the parting lines 69 using a punching machine or the like. The thickness of the first green sheet 60 a 1 dictates the depth of the groove 13 .
[0040] Next, a second green sheet 60 a 2 sized identically to the first green sheet 60 a 1 is prepared. The second green sheet 60 a 2 is a flat plate lacking the through-holes. Then, the first green sheet 60 a 1 and second green sheet 60 a 2 are stacked. Thus, as shown in FIG. 5B , the through-holes 18 become blind via-holes 19 .
[0041] Next, when the stacked sheet is cut along the parting lines 69 to form multiple units each destined to become a bottom ceramic layer 60 a having the overall configuration as shown in FIG. 5C . Then, when the wall ceramic layer 60 b and seat ceramic layer 60 c are stacked on and integrated with the bottom ceramic layer 60 a, a pre-calcination ceramic package 60 is formed. Although the wall ceramic layer 60 b and seat ceramic layer 60 c are not shown in FIG. 5(D) , printing is performed at the blind via-holes 19 of the bottom ceramic layer 60 a during application of vacuum suction. Thus, the external terminals 15 are formed by screen printing of a conductive paste including tungsten, molybdenum, or the like. The screen printing is not performed to the entire blind via-holes 19 . Rather, the conductive paste is applied only in the central portions of the blind via-holes 19 to form the grooves 13 . Although not specifically described, this screen-printing technique is also performed to the copper plating 12 of the wall ceramic layer 60 b and to the seat ceramic layer 60 c.
[0042] The stacked structure formed as described above is calcinated for a predetermined time at approximately 1500° C. to form the ceramic package 60 having the grooves 13 .
[0043] In the foregoing description, screen printing is performed after cutting along the parting lines 69 . However, the ceramic package 60 may be produced by a process having a different other than that described above. For example, screen printing of the conductive paste may be performed to the large green sheet 60 a before partition. Then the sheet is calcinated and cut along the parting lines 69 .
[0044] The foregoing description pertained to the package 60 being made of ceramic. Alternatively, the package can be made of a filled resin, with the same grooves 13 being formed around the external terminals 15 . Exemplary filled-resin materials are epoxy resin, bismaleimide-triazine (BT) resin, polyimide resin, glass epoxy resin, glass BT resin, and the like. With a resin package, the groove 13 may be formed by laser processing, drilling, routing, or the like.
[0045] In the foregoing description, the first green sheet 60 a 1 and the second green sheet 60 a 2 are stacked to form the bottom ceramic layer 60 a . Alternatively, a boss, die, or the like defining a shape complementary to the shape of the groove 13 may be urged against a single green sheet to form the grooves 13 .
Depth Profiles of Grooves
[0046] As explained above, the grooves 13 extend depthwise into the base board and can be formed by laser processing, drilling, routing, or the like to a base board made of a resin laminate. Alternatively, the grooves 13 can be formed by punching or similar method before calcining a ceramic base board.
[0047] FIGS. 6A-6D show representative sectional profiles of the grooves 13 . In FIGS. 1 to 5 described above, the sectional profile of the grooves 13 was rectangular. But, any of various other sectional profiles can alternatively be used. FIG. 6A depicts a triangular profile for the grooves 13 . Such a profile can be formed easily by drilling or routing. However, if the width and the depth of a triangular-profiled groove 13 are the same as a corresponding rectangular groove, the volume of the triangular groove is less than of the rectangular groove. Hence, the triangular groove can accept less overflowing solder SOL than a rectangular groove having the same depth and width.
[0048] FIG. 6B shows a groove 13 having a sectional profile that is semi-circular. This profile is suitable if the grooves are formed by embossing.
[0049] FIG. 6C shows a groove 13 that provides progressively larger cross-sectional area with increased depth. Although special routing or the like must be used to form such grooves, since the volume of the groove 13 increases with depth, the amount of overflowing solder SOL that can be accommodated in such a groove may be larger than with other types of grooves.
[0050] FIG. 6D shows rectangular grooves 13 formed with shoulders (i.e., the grooves are separated from the external terminals 15 by a distance ΔL).
[0051] The grooves 13 described above are formed directly at the sides of the external terminals 15 . However, the grooves need not be formed directly to the sides.
[0052] The grooves 13 described above formed as a single groove around each respective external terminal 15 . Alternatively, multiple grooves (e.g., two) can be formed around the terminals.
[0053] The foregoing description has been in the context of mounting an electronic device, such as piezoelectric oscillator 100 or crystal oscillator 150 , to a circuit board PB. This is not intended to be limiting. The principles described herein can be applied to other types of electronic devices, such as a package having Chip on Board (COB) structure, and Pin Grid Array (PGA) structure, or a Ball Grid Array (BGA) package. These various electronic devices are often manufactured using resin packages. Since a resin package has rich mechanical processability, grooves may be formed economically and with high precision using mechanical techniques such as drilling or routing.
[0054] The description has been in the context of crystal oscillators. Alternatively, a crystal unit may be used and, in particular, a large-sized device is preferable among electronic devices. Before applying the solder SOL, a solder resist may be applied to the circuit board PB between places where the solder SOL is to be applied.
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Electronic devices are disclosed that allow for surface-mounting using solder while preventing solder from overflowing between external terminals of the electronic device, or between pads on a circuit board to which the external terminals are soldered. An exemplary electronic device has a base board made of an insulating material and having an outer surface comprising at least one external terminal for surface mounting of the device to the circuit board. A groove is defined at least part way around the external terminal on the outer surface. The groove accommodates overflowed solder and thus prevents unintended spread flow of the solder to locations that otherwise could cause short circuits and the like. The electronic device can include a resin board containing a thermoset resin, wherein the groove is formed by thermal or mechanical processing.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates to improvements in cartridge holders and is particularly directed to cartridge holders adapted to releasably secure a round of cartridges for fast and simultaneously loading of the round into the chambers and the cylinders of revolvers.
II. Description of the Related Art
It is well known in the art to utilize a cartridge loader in loading cartridges into a revolver or other weapon. U.S. Pat. No. 3,722,125 to Switzer discloses a holder that releasably secures a round of cartridges within cartridge bores in a cylindrical housing. A manually rotated member selectively secures or releases the cartridges into the cylinder of the revolver. A positioning mechanism is provided to maintain the holder in either a release position or an engaged position. This locking mechanism is formed of several members and extends externally of the housing.
An improved cartridge loader by the same inventor is disclosed in U.S. Pat. No. 4,202,124. The cartridge loader has a star-shaped latch that selectively engages/releases the cartridges. A semi-automatic rotation device may be utilized to rotate the latch. The rotation device is also manually operable to set the latch from the releasing position to the capturing position by rotating a knob. Again, the mechanism that locks the loader into either a engaging position or a releasing position includes many members and extends outwardly from the loader body.
Another known type of cartridge loader is disclosed in U.S. Pat. No. 5,842,299 to Switzer et al. This patent is primarily directed at providing a cartridge loader for more than the standard five- or six-chambered revolver. However, a portion of the locking system for selectively positioning the holder into engaging or releasing positions is still located externally from the holder's casing.
Each of the aforementioned prior art cartridge loaders have externally extending members that reduce the efficiency of cylinder loading by creating a gap between the cartridge holder and the revolver's cylinders. One problem addressed by the present invention is that the cartridges may fall sideways instead of within the appointed cylinder due to the gap. Another problem addressed in the present invention is that damage or breakage could occur to exposed parts if the loader is dropped or otherwise subjected to force.
The present invention has no external parts to be broken off, and also efficiently loads the cartridges into the revolver.
The present invention contemplates a new and improved loader for a revolver, which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a new and improved cartridge loader for a revolver is provided. The cartridge loader includes a cylindrical loader body having spaced first and second surfaces, a cylindrical central cavity extending from the first surface into the loader body and a plurality of circumferentially located cartridge bores extending from the second surface into the loader body. A selectively rotatable pintle is received within the central cavity and operates between a closed position, at which cartridges may be temporarily stored, and an open position at which the cartridges may be released. Latching means are carried on the pintle and operable therewith. The latching means include a plurality of cartridge-engaging protrusions, each of which intersect a different one of the cartridge bores when the pintle is in the closed position and do not intersect the cartridge bores when the pintle is in the open position. The cartridge loader includes détente means positioned between the spaced surfaces of the loader body which selectively locate the pintle at the closed or open positions.
In accordance with another aspect of the invention, the détente means comprises a pin assembly including a lock pin and a spring wherein the lock pin is adapted for reciprocal movement in a plane generally perpendicular to the axis of rotation of the pintle; a pin-engaging surface including a first pin groove and a second pin groove wherein the lock pin is resiliently engaged in the first pin groove to locate the closed position of the pintle and resiliently engaged in the second pin groove to locate the open position of the pintle; and, reciprocating means for reciprocating the lock pin, the reciprocal means being positioned intermediate said first and second pin grooves.
In accordance with another aspect of the invention, the pin-engaging surface is formed in the pintle and the reciprocating means is a ball bearing held in a bearing groove formed in the pintle.
In accordance with another aspect of the invention, the pin-engaging surface is formed in the pintle and the reciprocating means is a rise formed in the pintle.
In accordance with another aspect of the invention, the central cavity extends a length less than a distance between the first and second surfaces of the loader body.
In accordance with another aspect of the invention, each of the cartridge bores extends a length less than a distance between the first and second surfaces of the loader body.
One advantage of the present invention is that the revolver can be quickly loaded.
Another advantage of the present invention is the simplicity of design as compared to other prior art loaders.
Another advantage of the present invention is that the détente means is contained within the loader body and is protected from contaminants and debris.
Another advantage of the present invention is the permanent assembly of the associated parts.
Still another advantage of the present invention is that the locking mechanism is internally located to prevent damage to exposed parts.
Yet another advantage of the present invention is that the absence of external projections on the side placed next to the revolver chamber permits more efficient loading of the cartridges.
Still other benefits and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts. A preferred embodiment of these parts will be described in detail in the specification and illustrated in the accompanying drawings, which form a part of this disclosure and wherein:
FIG. 1 is a top plan view of one embodiment of a cartridge loader according to the present invention showing the location of a plurality of cartridge bores in dotted lines;
FIG. 2 is a bottom plan view of the embodiment shown in FIG. 1 showing the location of the central cavity in dotted lines;
FIG. 3 is a sectional view of the embodiment shown in FIG. 1 cut along the line 3 — 3 when the pintle is in the closed position;
FIG. 4 is a sectional view similar to FIG. 3 cut along the line 4 — 4 of FIG. 1 when the pintle is in the open position;
FIG. 5 is a partial sectional view taken directly above the pin assembly of the embodiment shown in FIG. 4;
FIG. 6 is a partial sectional view taken directly above the pin assembly of the embodiment shown in FIG. 3;
FIG. 7 is an enlarged view of a portion of the view shown in FIG. 6, and,
FIG. 7A is a view similar to FIG. 7 of an alternate embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, which are for purposes of illustrating a preferred embodiment of the invention only, and not for purposes of limiting the same, FIG. 1 shows a top view of a new and improved cartridge loader 10 , including a loader body 12 with a series of circumferentially positioned cartridge bores 14 . In the preferred embodiment, the cartridge bores 14 do not extend entirely through the loader body 12 . However, simple modifications could be made to the preferred embodiment to include cartridge bores that extend entirely through the loader body 12 . Such modifications are within the scope of the present invention.
FIG. 2 shows a bottom view of the embodiment shown in FIG. 1. A central cavity 16 holds a rotatable pintle 30 , not shown in this view. In the preferred embodiment the central cavity 16 does not extend entirely through the loader body 12 in order to limit entry points for debris or contaminants. However, it is within the scope of the invention to provide a central cavity that extends entirely through the loader body 12 .
With reference to FIG. 3, the cartridge loader 10 is shown in the “closed” position as will be explained in further detail below. The loader 10 includes latching means 20 for selectively engaging an associated cartridge 18 when the loader 10 is in the closed position. The latching means 20 includes cartridge-engaging protrusions 22 which intersect the cartridge bores 14 when the loader 10 is in the closed position. For illustrative purposes only, an associated cartridge 18 is shown positioned within a cartridge bore 14 . As shown, the cartridge bore 14 is dimensioned to accommodate the larger diameter flanged end of the associated cartridge 18 . The cartridge-engaging protrusion 22 extends into the cartridge bore 14 to engage the flange 19 and thereby selectively secure the cartridge 18 . In the preferred embodiment, the latching means 20 are located at the end 32 of the pintle 30 that is contained entirely within the loader body 12 . Other embodiments anticipated by the inventor include a pintle 30 that extends all the way through the loader body 12 .
In FIG. 4, the cartridge loader 10 is shown in the “open” position where the latching means 20 is positioned such that the protrusions 22 do not intersect the cartridge bores 14 . In the “open” position, the cartridge 18 is released from the cartridge bore 14 and is therefore not shown in this view. The loader 10 is manipulated into the open position in order for associated cartridges 18 to be positioned therein. Thereafter, the loader 10 is manipulated into the closed position to selectively retain the associated cartridges 18 . Manipulation of the loader 18 again into the open position allows the retained cartridges 18 to disengage, as for example into a revolver chamber.
For ease of manufacture and operation, in the preferred embodiment, the latching means 20 is integral with the pintle 30 . However, it is within the scope of the invention to have a non-integral latching means 20 carried on the pintle 30 and rotatable therewith.
With reference to FIGS. 3-7, the salient features of one of the preferred embodiment of the present invention will be disclosed. The cartridge loader 10 includes a pintle 30 being rotatable about an axis 36 . Latching means 20 is operably associated with the pintle 30 . The pintle 30 is disposed in central cavity 16 . The pintle 30 may be rotated by manipulation of a knob 34 as is well known in the art. Knob 34 may be integral with pintle 30 , as in the preferred embodiment, or may be a separate attachment. The pintle 30 rotates between the “closed” position shown in FIGS. 3 and 5 and the “open” position shown in FIGS. 4 and 6. The extent of rotation is determined by détente means 37 which in the preferred embodiment include a pin assembly 38 , a pin-engaging surface 40 , and reciprocating means such as ball bearing 41 .
With particular reference to FIG. 7, the preferred pin assembly 38 includes a lock pin 42 and a resilient member such as spring 46 . The spring 46 and at least a portion of the lock pin 42 may be enclosed in a casing (not shown). The pin assembly 38 is disposed so that the lock pin 42 reciprocates is a direction generally perpendicular to the axis 36 of the central cavity 16 . During rotation of the pintle 30 , the ball bearing 41 retains its relative position in the loader body 12 and the lock pin 42 reciprocates due to compression and expansion of spring 46 . In the preferred embodiment, the loader body 12 may be formed of aluminum or other lightweight material while the ball bearing 41 and the lock pin 42 may be formed of steel or other durable material.
As best shown in FIG. 7, lock pin 42 may be selectively engaged within first pin groove 58 or second pin groove 60 to fix the limits of rotation of pintle 30 . Reciprocating means such as ball bearing 41 is located intermediate the pin grooves 58 , 60 . An alternate reciprocating means could be employed within the scope of the present invention. Although not preferred because of wear characteristics, it is possible to form a rise 64 between the first and second pin grooves 58 , 60 by extension of the pintle material as shown in FIG. 7 A.
As is apparent from FIG. 7, the détente means 37 also functions to prevent pintle 30 from becoming disengaged from the loader body 12 after the loader 10 has been assembled. At all times, lock pin 42 extends past the wall of the central cavity 16 .
Although one embodiment of latching means 20 has been disclosed above, the latching means 20 may differ therefrom without departing from the spirit and scope of the present invention. Additionally, a cartridge loader 10 incorporating other features known in the art or chosen with sound engineering principles, such as rim stops, bore closures, lighting devices and the like are within the scope of the present invention.
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of the specification. It is intended by applicant to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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An improved cartridge loader for releasable securement of cartridges to be simultaneously loaded into the cylinder of a revolver. A pintle rotates between a cartridge engaging position and a cartridge releasing position and is held in positive engagement with the loader body by the action of a spring-loaded pin assembly along a pin-engaging surface. The pin-engaging surface may be formed in the pintle and the pin assembly is substantially located within the loader body.
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This application is a division of application Ser. No. 10/099,960, filed Mar. 19, 2002, now U.S. Pat. No. 6,635,941.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and its manufacture method, and more particularly to a semiconductor device having photoelectric conversion elements and its manufacture method.
2. Related Background Art
A conventional image pickup module has a semiconductor chip with light reception elements and a substrate having lenses for converging light on the light reception elements. The semiconductor chip and substrate are mounted on both sides of a spacer to be spaced apart by some distance. Light can be converged on a light reception plane of each light reception element so that a real image can be formed.
FIGS. 18A , 18 B and 18 C are broken perspective views illustrating a conventional image pickup module manufacture method. FIG. 18A shows a substrate 917 having lenses for converging light on a light reception element, FIG. 18B shows a spacer 901 , and FIG. 18C shows a semiconductor chip 503 having light reception elements 100 . According to a conventional image pickup module manufacture method, the substrate 917 and semiconductor chip 503 are bonded on both sides of the spacer 901 to form an image pickup module. If each of a plurality of image pickup modules is manufactured by this method, a number of manufacture processes are required including an alignment process for the semiconductor chip 503 and substrate 917 .
FIGS. 19A , 19 B and 19 C are schematic cross sectional views illustrating another conventional image pickup module manufacture method.
FIG. 19A is a schematic cross sectional view of a semiconductor wafer 910 formed with a plurality of semiconductor chips, the wafer having some warp caused by a passivation film or the like formed by a semiconductor device manufacture process. This warp has a height difference of, for example, about 0.2 mm between the highest and lowest positions in the case of an 8-inch wafer. A wafer with a warp has a roll shape, a saddle shape, a bowl shape or the like.
As shown in FIG. 19B , the warp of the semiconductor wafer 910 is removed by sucking the bottom surface of the wafer 910 by using a jig 950 .
Next, as shown in FIG. 19C , the semiconductor wafer 910 and a substrate 917 are bonded together via a spacer 901 .
Thereafter, suction of the semiconductor wafer 910 is released to dismount the semiconductor wafer 910 and lens substrate 917 from the jig 950 . This assembly of the semiconductor wafer and lens substrate is cut along each semiconductor chip and lens to form an image pickup module. A method of bonding together the semiconductor wafer 910 with semiconductor chips and the substrate 917 by a single alignment process is suitable for the manufacture of a plurality of image pickup modules.
(First Technical Issue)
After the semiconductor wafer 910 is bonded via the spacer 901 to the lens substrate 917 having a plurality of lenses for diverging light on light reception elements, each image pickup module is formed by dicing the substrate along each scribe line between semiconductor chips. During dicing, a force is applied to the substrate 917 from a dicing blade. This force may change the surface shape of a lens and hence a reflectivity thereof, degrading a focussing performance.
It is therefore an object of the invention to efficiently manufacture a semiconductor device such as an image pickup module without changing the surface shape of a lens during dicing.
(Second Technical Issue)
With the manufacture method illustrated in FIGS. 19A to 19 C, after suction of the semiconductor wafer 910 is released, the semiconductor wafer 910 tends to recover the original warp state. If the lens substrate 917 is bonded to the semiconductor wafer 910 with a warp on the convex surface side, the semiconductor wafer 910 and lens substrate 917 are likely to be peeled off in the peripheral area of the semiconductor wafer 910 .
Conversely, if the lens substrate 917 is bonded to the semiconductor wafer 910 with a warp on the concave surface side, the semiconductor wafer 910 and lens substrate 917 are likely to be peeled off in the central area of the semiconductor wafer 910 .
If the semiconductor wafer 910 and lens substrate 917 are peeled off at the worst, or if an adhesive layer between the semiconductor wafer 910 and lens substrate 917 is elongated, the distance between the semiconductor wafer 910 and lens substrate 917 changes so that light cannot be converged correctly on the light reception element, disabling desired image pickup in some cases.
It is therefore another object of the invention to manufacture a semiconductor device such as an image pickup module capable of realizing reliable image pickup by considering a warp of a semiconductor substrate such as the semiconductor wafer 910 .
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a semiconductor device formed by cutting a first substrate and a second substrate bonded together by a spacer, wherein: the spacer is disposed at an end of the first substrate after cutting; the second substrate is a semiconductor wafer formed with a light reception element or elements; and the first substrate has an optical element or an optical element set for converging light on the light reception element or elements.
According to another aspect of the present invention, there is provided a semiconductor device manufacture method comprising: a step of bonding a first substrate and a second substrate by using a spacer; and a step of cutting the first and second substrates, wherein the step of cutting the first substrate cuts the first substrate at a position where the spacer is disposed under the first substrate.
According to still another aspect of the present invention, there is provided a semiconductor device manufacture method comprising: a step of holding the semiconductor substrate on a base under a condition that the warp is removed; a step of bonding an opposing substrate to the semiconductor substrates with a size adjusted according to the warp of the semiconductor substrate; and then a step of cutting the opposing substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic top view showing the structure of a semiconductor device according to a first embodiment of the invention.
FIG. 1B is a schematic cross sectional view taken along line 1 B— 1 B shown in FIG. 1 A.
FIG. 1C is a top view of a semiconductor chip shown in FIG. 1 A.
FIG. 1D is a schematic cross sectional view showing the semiconductor device of the first embodiment connected to an external electronic circuit.
FIG. 2 is a schematic cross sectional view showing an area near light reception elements 822 a and 822 b shown in FIG. 1 C.
FIG. 3 is a diagram showing the positional relation between image pickup areas and the subject images picked up with a compound eye lens mounted on the image pickup module of the embodiment.
FIG. 4 is a diagram showing the positional relation between pixels when the image pickup areas shown in FIG. 3 are projected.
FIG. 5 is a broken perspective view illustrating a semiconductor manufacture method according to the invention.
FIG. 6 is a top view of the spacer 901 shown in FIG. 5 .
FIG. 7 is a top view of a semiconductor wafer 910 to which a spacer 901 is bonded.
FIG. 8 is a top view of the semiconductor wafer 910 having the spacer 901 to which an optical element set 917 is bonded.
FIG. 9 is a top view of the semiconductor wafer 910 having the spacer 901 to which all optical element sets 917 are bonded.
FIG. 10 is a schematic cross sectional view illustrating a dicing process to be executed after all optical element sets 917 are bonded.
FIG. 11 is a graph showing the spectral transmittance characteristics of an infrared ray cut filter.
FIGS. 12A , 12 B, 12 C and 12 D are schematic diagrams illustrating semiconductor device manufacture processes according to a second embodiment of the invention.
FIG. 13 is a schematic top view of an optical element set.
FIG. 14 is a schematic top view of an optical element set.
FIG. 15 is a schematic plan view of a semiconductor wafer with semiconductor chips.
FIG. 16 is a schematic plan view of the semiconductor wafer shown in FIG. 15 to which the optical element sets shown in FIGS. 13 and 14 are bonded.
FIG. 17 is a schematic plan view of the semiconductor wafer on the whole surface of which the optical element sets are mounted.
FIGS. 18A , 18 B, and 18 C are broken perspective views illustrating a conventional image pickup module manufacture processes.
FIGS. 19A to 19 C are schematic cross sectional views illustrating another conventional image pickup module manufacture processes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will be described with reference to the accompanying drawings.
In the description of a semiconductor device of this invention, an image pickup module is used by way of example.
First Embodiment
FIG. 1A is a schematic top view showing the structure of a semiconductor device according to the first embodiment of the invention. FIG. 1B is a schematic cross sectional view taken along line 1 B— 1 B shown in FIG. 1 A. FIG. 1C is a top view of a semiconductor chip 503 shown in FIG. 1 A. FIG. 1D is a schematic cross sectional view showing the semiconductor device of the first embodiment connected to an external electronic circuit.
Referring to FIGS. 1A to 1 D, reference numeral 560 represents an infrared ray cut filter. Reference numeral 501 represents a light transmissive member constituting a first substrate after being cut. Reference numeral 506 represents a stop light shielding layer made of light shielding material, for example, offset printed on the infrared ray cut filter 560 on the light transmissive member 501 . Reference numeral 512 represents a compound eye optical element having a compound eye lens constituted of the infrared ray cut filter, stop light shielding layer 506 , and convex lenses 600 a and 600 c and unrepresented convex lenses 600 b and 600 d . In this embodiment, although the compound eye optical element having the compound eye lens constituted of four convex lenses is used, the number of lenses is not limited only to this, but it may be determined as desired. For example, an optical element having only one lens may be used. Reference symbols 810 a , 810 b , 810 c and 810 d represent stop apertures formed through the stop light shielding layer 506 . It is preferable that the optical axes of the lenses 600 a , 600 b , 600 c and 600 d are disposed coaxially with the stop apertures 810 a , 810 b , 810 c and 810 d . The infrared ray cut filter 560 may be omitted. In this case, a thinner image pickup module can be formed. Reference numeral 503 represents a semiconductor chip as a second substrate after being cut, the semiconductor chip having pixels (not shown) including light reception elements disposed two-dimensionally. Reference numeral 522 represents a spacer which determines the distance between the compound eye optical element 512 and semiconductor chip 503 . Reference numeral 509 represents an adhesive member for bonding the compound eye optical element 512 and semiconductor chip 503 via the spacer 522 . Reference numeral 513 represents an electrode pad or external terminal for externally outputting a signal supplied from a light reception element such as a MOS type image pickup element or a CCD image pickup element or a light emitting element. Reference numeral 508 represents a light shielding member formed in spaces surrounded by the compound eye optical element 512 , spacer 522 and semiconductor chip 503 , the light shielding member preventing optical crosstalk between the four convex lenses. Reference numeral 516 represents a micro lens for increasing a light conversion efficiency of each light reception element. Reference symbols 820 a , 820 b , 820 c and 820 d represent light reception areas in which light reception elements are disposed two-dimensionally on the semiconductor chip 503 . Reference numeral 514 represents an AD convertor for converting an output signal from each light reception element into a digital signal. Reference numeral 515 represents a timing generator for generating a timing signal for a photoelectric conversion operation of each light reception element. The spacer 522 may be made of any member which can determine the distance between the semiconductor chip 503 and compound eye optical element 512 . For example, members having a predetermined length may be used, or adhesive mixed with beads may be used.
Reference numeral 517 represents a multi-layer printed circuit board to be used as an external electronic circuit substrate. Reference numeral 520 represents a bonding wire for electrically connecting the electrode pad 513 and an unrepresented electrode pad on the multi-layer printed circuit board 517 . Reference numeral 521 represents thermosetting or ultraviolet ray hardening resin for sealing the peripheral area of the electrode pad 513 and bonding wire 520 . In this embodiment, epoxy resin is used as thermosetting or ultraviolet ray hardening resin. Instead of electrical connection by the bonding wire 520 , electrical connection by a TAB film may also be used. The ultraviolet ray hardening resin 520 is coated on the whole outer peripheral area of the image pickup module in order to obtain a mount stability of the image pickup module on the multi-layer printed circuit board. Reference symbols 822 a and 822 b represent light reception elements.
The image pickup module as the semiconductor device of the invention is characterized in that the spacer 522 is disposed at the peripheral sides of the compound eye optical element 512 . Namely, the light permissive member 501 as the first substrate before being cut is bonded via the spacer 522 to the semiconductor wafer as the second substrate before being cut into semiconductor chips 503 , and thereafter, the area where the spacer 522 exists under the light permissive member 501 is cut to form each image pickup module.
The spacer 522 is therefore disposed at the peripheral sides of the light transmissive member 501 .
The more detailed description will be given for an image pickup module manufacture method of this embodiment. As shown in FIG. 11 , the infrared ray cut filter 560 transmits 80% or more of electromagnetic waves (such as ultraviolet rays) having a wavelength in the range from 350 nm to 630 nm and hardly transmits electromagnetic waves (such as infrared rays) having a wavelength of 250 nm or shorter or 850 nm or longer.
The infrared ray cut filter 560 is formed on the whole surface of the light transmissive member 501 by vapor deposition or the like, and on this infrared ray cut filter 560 the stop light shielding layer 506 is formed. The stop light shielding layer 506 is disposed so as not to be superposed upon the adhesive member 509 along an ultraviolet ray incidence direction, so that ultraviolet ray hardening epoxy resin can be sufficiently hardened to form the adhesive member 509 . The stop light shielding layer has an island outer shape. In this invention, the adhesive member 509 is not limited only to ultraviolet hardening epoxy resin so that the stop light shielding layer 506 and adhesive member 509 may be superposed upon each other along the ultraviolet ray incidence direction. In this specification, the ultraviolet ray incidence direction is a direction indicated by an arrow X.
The semiconductor chip 503 and spacer 522 are bonded by displacing one from the other because the bonded structure is suitable for electrically connecting the electrode pad 513 and an external electronic circuit by a wiring lead by bonding or the like. The semiconductor chip 503 and spacer 522 may be bonded not by displacing one from the other. In this case, the compound eye optical element 512 is preferably disposed not by displacing it from the spacer 522 .
The semiconductor chip 503 will be described in more detail with reference to FIGS. 1B and 1C . As shown in FIG. 1B , between the compound eye optical element 512 and compound eye optical system 503 , the spacer 522 made of resin, glass, silicon or the like is disposed in order to hold them at a predetermined distance. The spacer 522 and semiconductor chip 503 may be bonded together by utilizing a bonding process to be used when a silicon on insulator (SOI) substrate is formed. It is preferable to bond them together by using adhesive metal which contains aluminum or indium. The convex lenses 600 a , 600 b , 600 c and 600 d are formed on the light transmissive member 501 by a replica method, an injection molding method, a compression molding method or the like. The convex lens 600 a - 600 d is a spherical surface Fresnel convex lens or a circular, axis-symmetrical, non-spherical surface Fresnel convex lens, respectively made of resin with which a curved image surface can be corrected more reliably as compared to a usual optical system using a continuous image surface.
The convex lenses 600 a to 600 d are bonded to the light transmissive member 501 by resin. A portion of resin is flowed in some cases to the peripheral area of each convex lens 600 a - 600 d such as an area between the convex lenses 600 a and 600 c . If the flowed resin reaches the cut surface of the light transmissive member, a force may be applied to the resin during cutting along a direction of peeling off the resin from the light transmissive member 501 . In such a case, the convex lenses 600 a to 600 d may have distortion. It is therefore preferable that the flowed resin does not reach the cut surface of the light transmissive member 501 .
The position of each of the stop apertures 810 a , 810 b , 810 c and 810 d along the optical axis direction determines a main light beam outside the optical axis of the optical system. Therefore, the stop position is very important from the viewpoint of controlling various aberrations. Since each convex lens 600 a - 600 d is formed on the image side, various optical aberrations can be corrected properly if the stop is positioned near at the center of a spherical surface approximating a Fresnel lens surface. If a color image is desired to be picked up, a green (G) transmissive filter, a red (R) transmissive filter and a blue (B) transmissive filter are disposed, for example, in a Bayer layout, near at each convex lens 600 a - 600 d along the optical axis. If a particular color image or an X-ray image is desired to be picked up, the particular color filter or phosphor is disposed. In this embodiment, although not shown, a green (G) transmissive filter, a red (R) transmissive filter and a blue (B) transmissive filter are disposed in a Bayer layout.
The micro lenses 516 and light shielding member 508 are formed on the semiconductor chip 503 . The micro lens 516 converges light on the light reception element in order to pick up an image of, for example, a subject with a low luminance. The light shielding member 508 prevents generation of optical crosstalk between light transmitted through the convex lens 600 a and light transmitted through the convex lens 600 c . The light shielding member is disposed between adjacent convex lenses.
If the light reception element 822 a and other elements shown in FIG. 1C are CMOS sensors, it is easy to mount the A/D convertor 514 and the like on the semiconductor chip 503 . If the A/D convertor 514 and the like and the adhesive member 509 are superposed upon each other on the semiconductor chip 503 , the area of the semiconductor chip 503 can be reduced, resulting in a low cost.
The adhesive member 509 is preferably disposed spaced apart from the dicing line. In this case, it is possible to prevent the quality of the image pickup module from being lowered by the adhesive member 509 melted or broken into fine pieces or carbon particles by friction heat of the dicing blade and attached to the convex lenses 600 a to 600 d.
The micro lenses are disposed on the light reception areas 820 a , 820 b , 820 c and 820 d such that peripheral lenses such as 516 are shifted more toward the center of the line interconnecting the centers of the light reception areas.
FIG. 1D shows the multi-layer printed circuit board 517 as an external electric circuit board, bonding wires for electrically connecting the multi-layer printed circuit board 517 side and the electrode pads 513 , and the thermosetting or ultraviolet hardening resin 521 for sealing the peripheral area of the electrode pad 513 and bonding wire 520 .
Sealing by the adhesive member 509 and thermosetting or ultraviolet hardening resin 521 can reliably prevent deterioration of the micro lenses 216 and filter layers to be caused by entered dusts, moisture in the air and electrolytic corrosion of aluminum layers.
The thermosetting or ultraviolet ray hardening resin 521 is coated on the whole outer peripheral area of the image pickup module in order to establish the mount reliability of the image pickup module 511 on the multi-layer printed circuit board 517 .
Since the electrode pad 113 and multi-layer printed circuit board 517 are connected by the bonding wire 520 , an ITO film or via metal body is not necessary and the cost can be reduced correspondingly. In place of the bonding wire 520 , a TAB film may be used.
FIG. 2 is an enlarged schematic cross sectional view showing an area near the light reception elements 822 a and 822 b shown in FIG. 1 C. In FIG. 2 , reference symbols 516 a and 516 b represent micro lenses formed above the light reception elements 822 a and 822 b , reference symbols 823 a and 823 b represent incident light fluxes passed through the stop apertures 810 a and 810 b . The micro lens 516 a is upward eccentric relative to the light reception element 822 a , whereas the micro lens 516 b is downward eccentric relative to the light reception element 822 b.
Only the light flux 823 a is incident upon the light reception element 822 a and only the light flux 823 b is incident upon the light reception element 822 b . The light fluxes 823 a and 823 b are inclined downward and upward relative to the light reception planes of the light reception elements 822 a and 822 b , and are directed toward the stop apertures 810 a and 810 b.
By properly selecting the eccentricity amounts of the micro lenses 516 a and 516 b , only a desired light flux becomes incident upon each light reception element 822 . The eccentricity amounts can be set so that a subject light beam passed through the stop aperture 810 a is received mainly in the light reception area 820 a , a subject light beam passed through the stop aperture 810 b is received mainly in the light reception area 820 b , etc.
With reference to FIGS. 3 and 4 , a mechanism of processing an electric signal converted in the light reception areas 820 a to 820 d of the image pickup module as a semiconductor device according to the first embodiment of the invention will be described. FIG. 3 is a diagram showing the positional relation between image pickup areas and the subject images picked up with the compound eye lens mounted on the image pickup module of the embodiment. FIG. 4 is a diagram showing the positional relation between pixels when the image pickup areas shown in FIG. 3 are projected. In FIG. 3 , reference symbols 320 a , 320 b , 320 c and 320 d represent four light reception element arrays formed on the semiconductor chip 503 . For the purposes of description simplicity, it is assumed that each of the light reception element arrays 320 a , 320 b , 320 c and 320 d has 8×6 pixels. The number of pixels is selected as desired and not limited only to the embodiment. The light reception element arrays 320 a and 320 d output G image signals, the light reception element array 320 b outputs R image signals, and the light reception element array 320 c outputs B image signals. Pixels in the light reception element arrays 320 a and 320 d are shown by a white square, pixels in the light reception element array 320 b are shown by a hatched square, and pixels in the light reception element array 320 c are shown by a black square.
Separation zones each having the size of one pixel in the horizontal direction and three pixels in the vertical direction are formed between adjacent light reception element arrays. Therefore, the center of a line connecting the centers of the light reception element arrays for outputting G image signals has the same vertical and horizontal positions. Reference symbols 351 a , 351 b , 351 c and 351 d represent subject images. Since pixels are disposed in a pixel shift layout, the centers 360 a , 360 b , 360 c and 360 d of the subject images 351 a , 351 b , 351 c and 251 d are offset from the centers of the light reception element arrays 320 a , 320 b , 320 c and 320 d by a quarter pixel distance toward the center 320 e of all the light reception element arrays.
As the light reception element arrays are reversely projected on the plane at a predetermined distance on the subject side, a projection shown in FIG. 4 is obtained. Also on the subject side, reversely projected pixel images in the light reception element arrays 320 a and 320 d are shown by a white square 362 a , reversely projected pixel images in the light reception element array 320 b are shown by a hatched square 362 b , and reversely projected pixel images in the light reception element array 320 c are shown by a black square 362 c.
Reversely projected images of the centers 360 a , 360 b , 360 c and 360 d of the subject images are superposed as one point 361 , and each pixel image in the light reception element arrays 320 a , 320 b , 320 c and 320 d is reversely projected so as not to superpose the centers of respective pixels. Since the white square outputs a G image signal, the hatched square outputs an R signal and the black square outputs a B signal, the subject can be sampled by pixels in the manner similar to an image pickup device having color filters disposed in the Bayer layout.
As compared to an image pickup system using a single image pickup lens, the Bayer layout disposing R, G, B and G color filters for 2×2 pixels on the semiconductor chip 503 can form a subject image having a size of 1 divided by a root of 2, assuming that the pixel pitch is fixed. The focal length of the image taking lens is therefore shortened by 1 divided by a root of 2, i.e., by ½. This is considerably suitable for making a camera compact.
The operation of the image pickup module shown in FIGS. 1A to 1 D will be described briefly. A subject light beam incident upon the optical element 512 passes through the stop apertures 810 a to 810 d and convex lenses 600 a to 600 d under the stop apertures and forms a plurality of subject images on the semiconductor chip 503 . The images are converged via the micro lenses 516 on respective light reception elements.
Since the color filters are disposed, four subject images of R, G, B and G are formed on respective light reception elements which convert received light into electric signals.
A method of manufacturing an image pickup module as a semiconductor device according to the invention will be described in detail with reference to FIGS. 5 to 10 . FIG. 5 is a broken perspective view illustrating the semiconductor manufacture method according to the first embodiment of the invention. Referring to FIG. 5 , reference numeral 901 represents a spacer including spacers 522 a and 522 b , reference symbols 503 a and 503 b represent semiconductor chips, and reference numeral 917 represents an optical element set having light transmissive members 501 a and 501 b formed with lenses, light shielding layers, unrepresented color filters and the like. First, the optical element set 917 having the light transmissive members 501 a and 501 b formed with convex lenses 600 a to 600 d is bonded to the spacer 901 . By dicing the area between the semiconductor chips 503 a and 503 b along a dicing line, an image pickup module with the semiconductor chip 503 a and an image pickup module with the semiconductor chip 503 b can be formed. A dicing area is an area where the space is formed under the light transmissive member 501 as the first substrate. A dicing line may be defined by a groove in the optical element set 917 formed by etching, metal marks formed through photolithography techniques, or resin projections formed by a replica. If the resin projections are formed by a replica at the same time when the convex lenses 600 a to 600 d are formed, the number of manufacture processes can be reduced.
FIG. 6 is a top view of the spacer 901 shown in FIG. 5 . The spacer 901 is separated by a division line 903 into the spacers 522 a and 522 b . The spacer 901 is formed with a plurality of openings 902 for guiding light fluxes passed through the convex lenses 600 a to 600 d to the light reception elements 822 .
FIGS. 7 to 10 are top views of a semiconductor wafer illustrating the processes of manufacturing semiconductor devices according to the embodiment. FIG. 7 is a top view of the semiconductor wafer 910 to which a spacer 901 is bonded. FIG. 8 is a top view of the semiconductor wafer 910 having the spacer 901 to which an optical element set 917 is bonded. FIG. 9 is a top view of the semiconductor wafer 910 having the spacers 901 to which all optical element sets 917 are bonded. FIG. 10 is a schematic cross sectional view illustrating a dicing process to be executed after all optical element sets 917 are bonded.
The semiconductor device manufacture method according to the invention will be described in detail. First, twenty two semiconductor chips 503 are formed on the semiconductor wafer 910 as the second substrate. Each semiconductor chip 503 has the structure shown in FIG. 1 C. The number of semiconductor chips to be formed on the semiconductor wafer 910 is selected as desired.
Since the semiconductor wafer 910 may have some warp, the semiconductor wafer 910 is sucked when the optical element sets 917 are bonded, in order to remove the warp of the semiconductor wafer 910 .
After the suction of the semiconductor wafer 910 is released later, a force is applied to the semiconductor wafer 910 to recover the original shape. This force may collide some optical element sets 917 with each other so that the distance between the semiconductor wafer 910 and the optical element sets 917 may be changed. In order not to change this distance, it is preferable to form some gap between adjacent semiconductor chips 503 .
There is a strong tendency that the area of a semiconductor wafer is becoming large. When the optical element sets 917 are bonded to the semiconductor wafer 910 in a sucked state, some gap formed between adjacent semiconductor chips 503 helps to manufacture image pickup modules of good quality.
The spacer 901 is aligned with the two semiconductor chips 503 and bonded to an adhesive member 509 on the semiconductor chips 503 . An arrow J indicates the position of a dicing line (FIG. 7 ).
The semiconductor wafer 910 made of crystal has electrical, optical, mechanical and chemical anisotropical characteristics. After the orientation of a pulled-up ingot is measured precisely by using X-ray diffraction, the ingot is sliced. Prior to slicing the ingot, a cylindrical ingot is formed with a straight portion called an orientation flat 909 which indicates the crystal orientation.
If a semiconductor element pattern of the semiconductor chip 503 is formed in alignment with the orientation flat 909 , precise alignment between the optical element set 917 and the wafer can be established by using a reference pattern formed on the optical element set 917 and the orientation flat 909 .
If the size of the optical element set 917 is set to the maximum size capable of being accommodated in the effective exposure size of a stepper, the number of image pickup modules manufactured from one wafer can be made large so that it is effective from the viewpoint of cost.
After the spacer 901 is bonded to the semiconductor chips 503 , the optical element set 917 is bonded by using thermosetting or ultraviolet ray hardening epoxy resin in the state that the opening 902 of the spacer 901 is aligned with the corresponding convex lens 600 . An arrow K indicates the position of the division line 903 of the optical element set 917 (FIGS. 6 and 8 ).
After the epoxy resin is semi-hardened by radiating ultraviolet rays, it is pressed until a predetermined gap is formed. Thereafter, the resin is completely hardened by a thermal treatment to fix the gap between the optical element set 917 and semiconductor wafer 910 so that a subject image can be focussed sharply on the light reception element array 912 .
The adhesive member 509 is preferably disposed spaced apart from the division line 903 or dicing line. In this case, it is possible to prevent the quality of the image pickup module from being lowered by the epoxy resin melted or broken into fine pieces or carbon particles by friction heat of the dicing blade and attached to the convex lenses 600 a to 600 d.
The optical element set 917 is bonded to each spacer 901 in the similar manner (FIG. 9 ).
Epoxy resin is used because hardening is gentle and hardening contraction variation is rare so that stress can be relaxed. In this embodiment, although thermosetting resin can be used as the material of the adhesive member, it is more preferable to use ultraviolet ray hardening resin because heating sufficient for hardening the thermosetting resin may deteriorate the printed coat of the micro lens, replica, and stop light shielding layer 506 respectively formed on the semiconductor wafer 910 .
The infrared ray cut filter 560 is formed in the peripheral area of the stop light shielding when the spectral transmittance of the infrared ray cut filter in this area is regulated to transmit ultraviolet rays, the epoxy resin can be hardened by ultraviolet ray radiation from a front of the semiconductor wafer 910 .
If the optical element sets 917 are bonded and fixed before each semiconductor chip 503 is cut from the semiconductor wafer 910 , the semiconductor wafer 910 and optical element sets 917 can be made parallel, i.e., the distance between the semiconductor wafer 910 and each optical element set can be made equal, more than if the optical element sets are not bonded and fixed before each semiconductor chip is cut. It is therefore possible that one-side unsharpness of an optical image is difficult to occur.
Lastly, the semiconductor wafer 910 is diced at the positions indicated by an arrow J, and the spacer 901 and optical element set 917 are cut at the position indicated by an arrow K. In dicing the semiconductor wafer 910 , a cutting working system or a laser working system disclosed, for example, in Japanese Patent Application Laid-Open Nos. 11-345785 and 2000-061677 may be used.
As shown in FIG. 10 , if a dicing blade is used, only the semiconductor wafer 910 is diced along the direction indicated by the arrow J from the bottom of the semiconductor wafer while cutting water is poured to cool the semiconductor wafer 910 . In FIG. 10 , reference numeral 523 represents a dicing blade.
Next, only the optical element set 917 and spacer 901 are cut from the top surface of the optical element set 917 .
More specifically, as the dicing blade 523 rotates in the direction indicated by an arrow L, the dicing blade pushes in this direction the semiconductor wafer 910 before the semiconductor chips 503 are separated. If the resin layer coupled to the convex lenses 600 a , 600 b , 600 c and 600 d exists on the dicing line, a force is applied to the resin layer in the direction of peeling off the resin layer from the glass substrate of the compound eye optical element 512 , and the surface precision of the convex lenses 600 a , 600 b , 600 c and 600 d may be degraded.
In this embodiment, since resin does not exist on the dicing line along which the dicing blade moves, a large force will not be applied to the convex lenses 600 a , 600 b , 600 c and 600 d so that the above problem can be solved. It is also possible to prevent the quality of the image pickup module from being lowered by the resin melted or broken into fine pieces or carbon particles by friction heat of the dicing blade 523 and attached to the convex lenses 600 a to 600 d.
With the above processes, the semiconductor wafer 910 and optical element set 917 are separated into rectangular pieces to obtain image pickup modules 511 shown in FIGS. 1A to 1 D. With the cutting processes described above, triangular pieces or hexagonal pieces may also be formed.
The image pickup module 511 is connected to the multi-layer printed circuit board 517 as shown in FIG. 1 D.
In the above embodiment, two spacers are used for the spacer 901 and two compound eye optical elements are used as the optical element set 917 . Three or four spacers and compound eye optical elements may also be used. In order to reduce the number of position alignment processes, the spacer 901 and the like may have the size similar to the semiconductor wafer 910 , and the openings 902 and convex lenses 600 are formed at positions corresponding to each semiconductor chip 503 on the semiconductor wafer 910 .
In this embodiment, although the image pickup module is used as an example of the semiconductor device, the embodiment may be applied to an image forming module having electron emitting elements formed on a semiconductor wafer 910 and light emitting elements such as phosphors formed on an opposing substrate, with a spacer 522 being interposed therebetween.
As described so far, according to the invention, a force is prevented from being applied to the first substrate 917 on the spacer during dicing. It is therefore possible to prevent the surface shape of a lens or the like formed on the first substrate from being changed. It is possible to provide a method of easily manufacturing a semiconductor device such as an image pickup module without changing the lens surface shape and without deterioration of a focussing performance.
Second Embodiment
FIGS. 12A to 12 D are schematic diagrams illustrating semiconductor device manufacture processes according to a second embodiment of the invention. In FIGS. 12A to 12 D, reference numeral 910 represents a semiconductor substrate with a warp such as a semiconductor wafer having a plurality of semiconductor chips formed thereon, reference numeral 950 represents a jig for sucking the semiconductor wafer 910 from its bottom surface to remove the warp of the semiconductor wafer, and reference numeral 917 represents optical element sets as an opposing substrate.
In FIGS. 12A to 12 D, like elements represented by identical reference numerals to those of the first embodiment have been described earlier, and the description thereof is omitted. As shown in FIG. 12A , the semiconductor wafer 910 has some warp caused by a passivation film formed by a semiconductor device manufacture process. This warp has a height difference of about 0.2 mm between the highest and lowest positions in the case of an 8-inch wafer. A wafer with a warp has a roll shape, a saddle shape, a bowl shape or the like.
In order to prevent the generation of stress when the suction of the bottom surface of the semiconductor wafer 910 is released, it is necessary to adjust the number of optical elements in each optical element set. Namely, if the semiconductor wafer 910 has a warp whose convex and concave curves have a low frequency as small as about twice the diameter of the semiconductor wafer, the number of optical elements in each optical element set is made large to cover the semiconductor wafer 917 with a small number of optical element sets. If the semiconductor wafer 910 has a warp whose convex and concave curves correspond to about the diameter of the semiconductor wafer, the number of optical elements in each optical element set is made small to cover the semiconductor wafer 917 with a number of optical element sets. A gap P is preferably about 10 μm to 500 μm by considering a size variation of optical element sets. The frequency characteristics of the warp of the semiconductor wafer 910 can be obtained by frequency analysis of the surface shape. There is a general tendency that the larger the wafer size, the convex and concave curves have the smaller frequency. Therefore, the semiconductor wafer 910 is sucked from its bottom surface by using the jig 950 when optical element sets 917 are bonded to the semiconductor wafer 910 , to thereby remove the warp of the semiconductor wafer 910 (FIG. 12 B). More specifically, the semiconductor wafer 910 is sucked to the jig 950 by using an unrepresented sucking machine so that the whole bottom surface of the semiconductor wafer 910 becomes in contact with the jig. In this state, a plurality of spacers 901 are bonded to the semiconductor wafer 910 , with the mount positions being aligned. Next, the optical element sets 917 are aligned in position with the optical element sets 917 , and bonded thereto by using adhesive (FIG. 12 C). After the adhesive is hardened, the suction is released.
The spacer 901 is disposed for bonding together the semiconductor wafer and optical element sets 917 . This spacer may be omitted.
The size of an optical element set 917 are determined corresponding to the size of the warp of the semiconductor wafer 910 . It is necessary that if the semiconductor wafer 910 has a larger warp, the spacer 901 and optical element set 917 are made smaller. The reason for this is as follows. When the suction of the semiconductor wafer 910 to the jig 950 is released, a force is generated to recover the original shape of the semiconductor wafer 910 . This force makes adhesive have a creeping phenomenon. If the spacer 901 and optical element set 917 are made larger even if the convex warp is large, the distance of the optical element set 917 and semiconductor wafer 910 becomes longer from the semiconductor chip 503 nearer to the center of the semiconductor wafer 910 . In this case, the focus point of the image pickup module is displaced from pixels.
Conversely, if the spacer 901 and the like is made larger, a balance between the compound eye optical element 512 and semiconductor chip 503 of each image pickup module can be obtained more easily and the number of position alignments is reduced. From these viewpoints, if a warp of a bowl shape has a height difference of about 0.2 mm between the highest and lowest positions in the case of an 8-inch wafer, and about six hundreds semiconductor chips 503 having a side length of about 6 mm are to be formed, the size of the spacer 901 and the like is set to the size of three semiconductor chips disposed in parallel to the side. FIGS. 12A to 12 D show pluralities of an optical element sets 917 , it also can be only one optical element 917 set on the semiconductor wafer 710 .
The gap P which is between a plurality of an optical element sets 917 is set with a size corresponding to the warp of the semiconductor substrate in order to prevent the distance between the semiconductor wafer 910 and optical element set 917 from being changed by the adhesive layer elongated or peeled-off by the creeping phenomenon of adhesive which occurs when a plurality of optical element sets 917 abut on each other when the suction of the semiconductor wafer 910 to the jig 950 is released (FIG. 12 D). Since there is the tendency that semiconductor wafers are becoming large, when the optical element sets 917 are bonded to the semiconductor wafer 910 in a sucked state, some gap P formed between adjacent semiconductor chips helps to manufacture image pickup modules of good quality. The optical element such as shown in FIG. 1 A and the optical element set 517 such as shown in FIG. 5 may be used. The optical element set 517 shown in FIG. 5 has two optical elements. The number of optical elements to be cut from the optical element set is determined as desired.
With reference to FIGS. 13 and 14 , other examples of the optical element set will be described.
FIG. 13 is a schematic top view of an optical element set 962 . In FIG. 13 , reference numeral 963 represents a lens. The optical element set 962 has a cross shape. By using this optical element set 962 , five image pickup modules each having one lens can be manufactured. The pitch of lenses 963 is the same as that of semiconductor chips on an unrepresented semiconductor wafer 910 so that each image pickup module has the lens of the optical element set 962 bonded to the semiconductor wafer 910 .
FIG. 14 is a schematic top view of an optical element set 964 . In FIG. 14 , reference numeral 965 represents a lens. The optical element set 964 has a rectangular shape. By using this optical element set 964 , four image pickup modules each having one lens can be manufactured. The pitch of lenses 965 is the same as that of semiconductor chips on an unrepresented semiconductor wafer 910 so that each image pickup module has the lens of the optical element set 964 bonded to the semiconductor wafer 910 .
The shape of the optical element set is not limited only to the cross shape or rectangular shape, but it may be a T-character shape, an I-character shape, an L-character shape or the like.
With reference to FIGS. 15 to 17 , the semiconductor device manufacture processes according to the embodiment will be described in more detail.
FIG. 15 is a schematic plan view of a semiconductor wafer with semiconductor chips. In FIG. 15 , reference numeral 960 represents a semiconductor wafer, and reference numeral 961 represents a semiconductor chip.
FIG. 16 is a schematic plan view of the semiconductor wafer shown in FIG. 15 to which the optical element sets shown in FIGS. 13 and 14 are bonded.
FIG. 17 is a schematic plan view of the semiconductor wafer on the whole surface of which the optical element sets are mounted.
Normally, the semiconductor wafer 960 is formed with as many semiconductor chips 961 as possible as shown in FIG. 15 . However, as described with reference to FIG. 7 and the like, if the optical element set 917 and spacer 901 are bonded to two semiconductor chips 503 , some semiconductor chips 961 cannot be used in some cases. These semiconductor chips 961 are those formed in the peripheral area of the semiconductor wafer 960 excepting the area near the orientation flat.
In order to avoid this, as shown in FIG. 16 , the optical element sets 963 are disposed in a zigzag manner and bonded to the semiconductor wafer in such a manner that the corners of the optical element sets 965 are aligned with the convex corners of the optical element sets 963 . As shown in FIG. 17 , the optical element sets 965 and 963 are disposed on all semiconductor chips 961 on the semiconductor wafer 960 . The gap Q is formed between adjacent optical element sets 963 along their longitudinal direction by considering the warp of the semiconductor wafer 960 . In this embodiment, for the purposes of description simplicity, the optical element sets 963 and 965 shown in FIGS. 13 and 14 are used. However, as shown in FIG. 17 , some optical element sets 963 and 965 cannot be used. To avoid this, in a practical case, optical element sets having the shapes in conformity with those of the semiconductor chips 961 formed on the semiconductor wafer 960 are used to manufacture image pickup modules.
As described so far, according to the invention, a semiconductor manufacture method is provided which can make a semiconductor substrate and an opposing substrate be difficult to be peeled off even if the semiconductor substrate tends to recover the original warp when it is dismounted from a jig (base).
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A semiconductor device formed by cutting a first substrate and a second substrate bonded together by a spacer, wherein: the spacer is disposed at an end of the first substrate after cutting; the second substrate is a semiconductor wafer formed with a light reception element or elements; and the first substrate has an optical element or an optical element set for converging light on the light reception element or elements. A method of manufacturing such a semiconductor device. A semiconductor device manufacture method includes: a step of detecting a warp of a semiconductor substrate; a step of holding the semiconductor substrate on a base under a condition that the warp is removed; a step of bonding an opposing substrate to the semiconductor substrate; and a step of cutting the opposing substrate, wherein the opposing substrate bonded to the semiconductor substrate is set with a size corresponding to the warp of the semiconductor substrate or with a gap to an adjacent opposing substrate.
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FIELD OF THE INVENTION
[0001] The present invention relates to a reproducible method for preparing the amorphous form of atorvastatin calcium salt, in such a way as to be easily filtered, and with-a purity superior to the initial crystalline form.
STATE OF THE ART
[0002] Atorvastatin is a well known active pharmaceutical principle widely used for the treatment of diseases caused by hypercholesterolaemia. U.S. Pat. No. 4,681,893, U.S. Pat. No. 5,273,995, U.S. Pat. No. 6,121,461, U.S. Pat. No. 5,969,156 refer to the preparation of the product both in amorphous and crystalline form. While the production of a composition with a well defined crystalline form can in many cases be advantageous from the point of view of stability and from the point of view of the dosage of the active principle in the pharmaceutical formulation, in some cases this can give rise to water solubility is and bioavailability differences. This is the case with atorvastatin where the corresponding amorphous form demonstrates superior characteristics of water solubility and bioavailability than the corresponding crystalline form. On the other hand the known processes for producing atorvastatin in amorphous form present problems due to the poor reproducibility and/or poor workability of the product or are not suitable for scale up to industrial production.
[0003] For example in U.S. Pat. No. 6,087,511 and U.S. Pat. No. 6,274,740 are described the preparation of the amorphous form of atorvastatin calcium salt starting from the crystalline form (I) by evaporating the solution of the product in organic solvents such as tetrahydrofuran or tetrahydrofuran-toluene, until a foamy solid residue is obtained. This method presents considerable drawbacks from the point of view of industrial application. In regard to the workability of the product, at the end of the preparation a fragile foam is obtained which must be broken up in the reactor and must be discharged from the reactor as a solid.
[0004] WO007116 reports the production of atorvastatin in amorphous form from a solution of the product in a non-hydroxylic solvent. In this case high levels of hydrocarbon are necessary to obtain the desired product.
[0005] WO0128999 describes the preparation of amorphous atorvastatin by precipitating the product from solutions of atorvastatin calcium salt in lower alkanols. In this case enormous quantities of alcohols are necessary to obtain the desired product.
TECHNICAL PROBLEM
[0006] It was therefore considered necessary to provide a method for producing atorvastatin in amorphous form that was economically advantageous and at the same time industrially scalable.
SUMMARY OF THE INVENTION
[0007] The applicant has unexpectedly found that atorvastatin calcium salt can be produced in amorphous form, by a method that does not present the inconveniences of the state of the art.
[0008] In particular the process of the present invention comprises:
a) dissolving the atorvastatin calcium salt in an organic solvent miscible with water, b) gradually adding said solution to water while stirring, c) filtering and vacuum drying the solid obtained.
DESCRIPTION OF THE FIGURE
[0012] FIG. 1 shows the x-ray diffraction spectrum of the amorphous atorvastatin prepared as described in example 1.
[0013] The measurements were made at the wavelengths Kα1 and Kα2 using 5.0000° for angle 2θ and 35.0000° for the final angle. In this figure,in ordinates the number of counts per second is reported, and in abscissae the values of the angle 2θ.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The atorvastatin used as starting material can be either crystalline or amorphous. Consequently the atorvastatin used in stage (a) of the process of the present invention can therefore be crystalline atorvastatin of form (I), (II) and (IV) as described in U.S. Pat. No. 5,969,156 form (III) as described in U.S. Pat. No. 6,121,461 or the amorphous form derived from the reaction described in U.S. Pat. No. 5,273,995.
[0015] Preferably this latter type of atorvastatin is used.
[0016] The water miscible solvent is preferably chosen from: tetrahydrofuran, dimethylsulphoxide, dimethylacetamide, dimethylformamide, N-methylpyrrolidone, sulfolane. The additional advantage of this method is that the product obtained, whose amorphous nature is confirmed by the relative x-ray diffraction spectrum, has a higher purity than the starting product.
[0017] Preferably the atorvastatin calcium salt is dissolved in a quantity of organic solvent between 0.5 and 20, more preferably between 1 and 10 and even more preferably between I and 5 ml/gram of the atorvastatin calcium salt in crystalline form. The amount of water, to which the atorvastatin in organic solvent is slowly added, is preferably between 5 and 100, more preferably between 10 and 50, and even more preferably between 10 and 30 ml/gram of atorvastatin calcium salt in crystalline form. The temperature of the constantly stirred water is between 5 and 40° C., preferably between 10 and 30° C. Preferably the water soluble organic solvent is tetrahydrofuran. As the solution of atorvastatin calcium salt in the organic solvent is dripped onto the stirred water, the formation of a solid is observed which becomes more consistent as the addition proceeds. At the end of the addition the mixture is stirred for a period of time between 0.5 and 5 hours, preferably between 1 and 3 hours and even more preferably between 2 and 3 hours at a temperature of between 5 and 40° C. and preferably between 10 and 30° C., after which the suspension is filtered and the solid washed with water.
[0018] A further advantage of this method lies in the good filterability of the solid obtained due to the addition of the organic solution to the water. Indeed the addition of water to the organic solution results in the formation of gummy masses which cannot be filtered or stirred.
[0019] Some illustrative but non-limitative examples are given hereinafter of the preparation process according to the present invention.
EXAMPLE 1
[0020] 5 g of crude amorphous atorvastatin calcium salt derived from the reaction mixture of the process described in U.S. Pat. No. 5,273,995 are dissolved in 15 ml of THF and loaded into a dropping funnel. The funnel is placed above a 250 ml reaction flask equipped with mechanical stirrer. 100 ml of deionized water are loaded into the reactor and maintained at 22-25° C. and from the dropping funnel the THF solution is added to the water, resulting in the formation of a white solid. When the addition is complete the suspension is cooled to 10° C. while stirring and maintained at that temperature for. 1 hour. The precipitate is then filtered off under reduced pressure and washed with 20 ml of deionized water. 13.4 g of a wet product is obtained which, after drying for 12 hours at 40° C. under reduced pressure (50 mm Hg) gives rise to 4.8 g of atorvastatin calcium salt in amorphous form (yield 95%), of a purity superior to that of the initial crude atorvastatin evaluated by means of TLC as comparison.
[0021] FIG. 1 shows the x-ray diffraction spectrum of the atorvastatin calcium salt in amorphous form thus obtained, a spectrum-which is entirely in accordance with those already reported in the literature for such a product.
EXAMPLE 2
[0022] A 500 ml reactor equipped with mechanical stirrer and dropping funnel is filled with 200 ml of deionized water, maintained at 22-25° C. 20 g of crude amorphous atorvastatin calcium salt derived from the reaction mixture of the process described in U.S. Pat. No. 5,273,995 are dissolved in 30 ml of N,N-dimethylacetamide and loaded into the dropping funnel. The organic solution is then slowly dripped onto the water and a white solid is formed. At the end of the addition the mixture is stirred for about 1 hour at 22-25° C. and is then cooled to 10° C. and maintained at that temperature for 1 hour. The solid is filtered off, washed with 50 ml of cold deionized water and dried under vacuum at 40° C. for 12 hours to give 18.2 g of atorvastatin calcium salt in amorphous form (yield 91%) of a purity superior to the initial crude atorvastatin evaluated by means of TLC as comparison.
EXAMPLE 3
[0023] The reaction is conducted starting from 20 g of atorvastatin calcium salt using the same conditions as in example 2, with the only difference that dimethylsulphoxide is used as the organic solvent miscible in water. After drying, 17.5 g of atorvastatin calcium salt in amorphous form are obtained (yield 87.5%) of a purity superior to the initial crude atorvastatin evaluated by means of TLC as comparison.
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Process for preparing atorvastatin calcium salt in amorphous form comprising: a) dissolving the atorvastatin calcium salt in an organic solvent miscible with water, b) gradually adding said solution to water while stirring, c) filtering and vacuum drying the solid obtained. Formula
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This application is a continuation of application Ser. No. 06/137,174, filed Apr. 4, 1980 abandoned.
FIELD OF THE INVENTION
The invention relates to a drilling device for drilling a core in deep drilled holes consisting of a direct drive (i.e. downhole motor) set up with the drill hole end of a pipe line connectable to the drill flushing fluid and of a core drill device which comprises a direct drive attached to the rotor, an outer sleeve supporting an auger tip and a core sleeve coaxially arranged in the latter which limits an annular space with the outer sleeve, the part of the axial flow path of the drill flushing fluid passage through the drill tool and its inner end facing to the direct drive is provided with a check valve opening with the occurrence of a pressure drop from the inner cavity of the core sleeve to the environment.
BACKGROUND OF THE INVENTION
With well known drilling devices of this kind, which find application in individual core processes, the check valve on the inner end of the core sleeve has the task to allow the exit from the latter the flushing liquid used in the drilling operation with continuous washing of the core in the core sleeve.
SUMMARY OF THE INVENTION
This invention has for its basis to create a core drill device of the stated type in which the possibility is given of a flushing of the core sleeve in order to remove from the latter, prior to the start of a core drilling process, drilling debris and similar components which have accumulated there with the introduction of the drilling device into the drill hole.
This problem is solved according to the invention first of all in such a way that the core sleeve is connected by way of an inlet channel with the flow path of the drill flushing fluid and permits flow of the drill flushing fluid in the direction to the drill hole bottom as well as including a stop valve cutting off the participation of this flow of the core sleeve. Through the passage opening created in this manner in the area over the core sleeve for drill flushing, the flushing liquid can now be introduced into the upper end of the core sleeve and in the lower open end be carried out in order to flush the core sleeve thoroughly prior to the start of a coring process.
The stop valve makes possible the interruption of the flushing of the core sleeve to a specific desired time. The flushing possibility of the core sleeve is fundamentally given in the scope of the invention when the direct drive is already running or also then when the latter is still not running.
In a further development of the invention the core sleeve has in the inlet channel for the drill flushing a valve seat surrounding a passage opening for the latter as part of the stop valve on which a separate, independent valve body of the stop valve is displaceable. It is especially appropriate, in the flow direction of the drill flushing fluid upstream of the core sleeve in the drilling device, to provide a releasable storage device for at least one such releasable valve body of the stop valve. A single valve body is sufficient if the stop valve is formed at the same time as a check valve for an exit of flushing liquid in continuous washing of the core, while two valve bodies are provided when two valves with separate functions are provided. Both possibilities are given within the scope of the invention.
Numerous further characteristics and advantages of the invention result from the claims and the following description in connection with the drawing in which several type model examples of the subject of the invention are schematically made clear.
DESCRIPTION OF THE DRAWINGS
In the drawing are shown:
FIG. 1 an initial type model example of a core drilling device in a schematic longitudinal section,
FIG. 2 a detail of the drilling device according to FIG. 1 in enlarged scale vis a vis the latter, and
FIGS. 3 to 9 each a further type model example of a core drilling device according to the invention in a representation corresponding to FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
As is evident first of all from FIG. 1 the core drilling device comprises a direct valve 1 according to a MOINEAU design having a stator 2 forming the outer body of the drive and a rotor 3 forming an inner body of the drive which by well known ways limit a working space between them. The stator 2 of the direct drive 1 is firmly connected with the stationary drill pipe line not further represented. By means of the latter flushing liquid as a work medium is pumped downwards and enters the work space under high pressure through which it undergoes a helical path; in so doing a part of the pressure energy of the work medium is transformed into rotational energy for the tool.
The rotor 3 is connected by way of a jointed shaft 4 and a reversing tube section 5 attached to the latter for the flushing liquid with a screwed on hollow shaft 6 to the bearing block 7 of the direct drive 1.
In addition, the drilling device comprises as a whole the core drill device designated by 8 which for its part consists of an outer sleeve 9 with a core drill tip 10 attached to the bottom end and an inner core sleeve 11. On its upper end the core sleeve is screwed onto a sleeve section 12 of a smaller diameter. By means of a bearing device 13 between the outer sleeve 9 and the sleeve section 12 the unit formed by the latter and the core sleeve 11 is held coaxially to the outer sleeve 9 of the core drill device 8. The sleeve unit 11,12 bounded by an annular space 14 with the outer sleeve 9, the part of the axial flow path of the drill flushing fluid is formed through the drilling device.
The sleeve section 12 is constructed open on the upper side and defines an inlet channel 15 for flushing liquid to the core sleeve 11. By this means the core sleeve 11 is capable of flow through by the flushing liquid in a direction to the drill hole bottom or to the drill tip 10 as is represented by an arrow 16 in FIG. 1.
Such a flushing of the core sleeve 11 takes place prior to a core drilling operation in which the direct drive 1 in the example according to FIG. 1 is running and the flushing liquid exiting from the work space formed between the stator 2 and rotor 3 through the reversing tube section 5 corresponding with the arrows 17 enters into the hollow shaft 6; this as well flows through subsequently a connecting sleeve section 18 and at 16 into the inlet channel 15 in order to flush out the core sleeve 11.
The flushing of the core sleeve 11 can be interrupted in its entirety by means of a stop valve designated by 19 which comprises a valve seat 20 which surrounds a flow through opening 21 in the inlet channel 15 for the drill flushing. On this valve seat 20 is a separate, independent valve body 22 for example in the shape of a ball which is displaceable.
The valve body 22 can be restrained for example during the flushing of the core sleeve 11 in the inlet channel 15 and there be arrested against a downward directed interrupted motion for example by means of a latch. By means of a compressive or tensional force or, by a discharge torque moment, the arrestation for the valve body 22 can be raised and the latter released for the displacement motion on its valve seat 20.
An especially advantageous, in no way limiting construction however, is provided to the process of flushing so that the valve body 22 of the stop valve 19 for flushing of the core sleeve 11 is held outside of the inlet channel 15 for the flushing liquid and then is thrown into the inlet channel 15 when the flushing of the core sleeve 11 is to be interrupted.
This is achieved in the type example according to FIG. 1 by means of a storage device 23 placed in the connecting sleeve section 18 upstream of the core sleeve 11 or its inlet channel 15 for the valve body 22. The storage device 23 which is represented in enlarged scale in FIG. 2 comprises an outer housing constructed with an opening 24 for the removal of the valve body 22 from the connecting sleeve section 18 and an annular body 25 arranged on the inside of the connecting sleeve section 18. The annular body 25 is axially displaceable in the connecting sleeve section 18 and has a peripheral opening 26 for a passage of the valve body 22 with an axial displacement of the annular body 25. According to the example illustrated the annular body 25 is under the preloading of a helical spring 27 and is formed as a piston housing which, when a certain flushing pressure is applied, performs a downward motion against the spring effect so that the valve ball 22 passes through the peripheral opening 26 and through the inlet channel 15 and can reach the valve seat 20 as is illustrated in 22' by dot-dash lines in FIG. 1. In FIG. 2 in the right half the closed position of the annular body 25 is illustrated in which the valve body 2 is kept back in the storage device 23 and in the left half of which is shown displaced in the downward position which has led to the passage of the valve body 22 through the opening 26.
If the valve body 22 is in the 22' position on its valve seat 20, then the process of flushing of the core sleeve 11 is interrupted. The flushing liquid then proceeds on its way through the annular space 14 to the drill tip 10 as is illustrated by means of a dashed line designated by the arrow 28. The drilling device is now driven for the drilling of a core. In so doing the outer sleeve 9 supporting the drill tip 10 rotates on the basis of its connection to the rotar 3 of the direct drive 1 while the core sleeve 11 by way of its engagement around the core, is stopped. The stop valve 19 at the same time acts as the non-return valve for the removal of flushing liquid out of the extension sleeve 12 of the core sleeve 11 with continous washing of the core in the core sleeve 11.
The attachment of the storage device between the direct drive 1 and the core sleeve 11 guarantees that the stop valve 19 is already present on the spot and ready to function which offers the fundamental advantage that existing direct drives and existing core drilling devices can be inserted. With such a design as is illustrated in FIG. 1 the passage opening for flushing fluid is beneath the end of the direct drive and leads, as is shown by means of the arrows 17, into the center of the customarily hollow bearing block shaft 6 which is in flow connection with the core sleeve 11.
The valve seat 19 can be arranged in any position in the range between the stated passage opening for the flushing liquid and the upper end of the valve seat as well as additional passage openings 40 are found through which flushing medium again is then transferable into the outer annular space 14 between core sleeve 11 and outer sleeve 9 when the valve body 22 is occupied closing its valve seat 19. The valve set 19 is, as is shown, arranged in the upper region of the sleeve unit 11 12 and the passage openings 40 for the return of the flushing medium into the annular spaced 14 is directly over it in order to draw out the bearing device 13 etc. of the flushing in the core drill operation.
While in the type model example according to FIG. 1, the direct drive 11 is running during the flushing of the core sleeve 11, this is avoided in the type model example according to FIG. 3, which can be preferred for a facilitated entry of the drilling device into the drilling hole. The fundamental construction principle of the type model example according to FIG. 1 in regard to the direct drive 1 with the stator lying outside and with the inner or central rotor 3, is also retained in the type model example according to FIG. 3 so that for this as also for numerous additional coinciding construction parts the same reference symbols are used.
The species according to FIG. 3 is differentiated from that of FIG. 1 essentially in such a wy that the direct drive 1 has a central axial passage channel 29 for drill flushing which extends through the rotor 3 and whose entrance opening 30 is located upstream of the direct drive 1. The rotor 3 or its passage channel 29 is again by way of the jointed shaft 4 and the return sleeve section 5 for the flushing liquid connected with the bearing block shaft 6. In the present type model example the jointed shaft 4 is constructed as a hollow shaft with a central passage channel 31 in the extension of the passage channel 9 of the direct drive 1. In the region of the entrance opening 30 of the passage channel 29, an additional stop valve 32 is provided which closes the central passage channel 29 of the direct drive 1 or opens it when the flushing of the core sleeve 11 is to be ended. The second stop valve 32 has for its part a valve seat 33 leaving a passage opening for drill flushing fluid for a separate, independent valve body 34 displaceable on the latter in which again in the example illustrated is in the shape of a ball. The valve body 34 is supported by a spring 35 pressing from below for a flushing of the core sleeve 11. Up to a specific pressure in flushing, the stop valve is open and therewith the central flow of the direct drive 1 is given in the direction to the core sleeve 11. The core sleeve is correspondingly flowed through with the flushing fluid while the direct drive 1 is stationary, since the work spaces formed between the stator 2 and rotor 3, because of the open transmission channel 29, not flowed through to any significant extent by the flushing liquid as a work medium. If the flushing pressure increases over the predetermined value then the stop valve 32 closes by activation of the valve body 34 by overcoming the force of the spring 35 on the valve seat 33 so that the flushing liquid now flows through the work space of the direct drive 1 and the latter becomes active.
During the flushing of the core sleeve 11 the first stop valve 18 is of course also in the open position which also in this type model example works with the storage device 23 for the valve body 22. This releases in the manner already described with the help of the type model example according to FIG. 1 in reaching the prestated flushing pressure on the valve body 22 so that the latter arrives by means of the inlet channel 15 on its valve seat 20 as is illustrated by dashed lines 22' in FIG. 3. During the flushing of the core sleeve 11 with stop valves 32 and 19 opened, the flushing liquid therefore takes a flow path corresponding to the arrows 36 37 38 designated by solid lines while it takes, with stop valves 32 and 19 closed, a flow path corresponding to the dashed line designated arrows 39 40 and 41. The valve body 22 in its closed position 22' is admitted only by the reduced pressure of the flushing liquid through passage of the flushing liquid through the direct drive 1 so that since in the drill operation also within core sleeve 11 the pressure in general is equal to or less than this pressure, the stop valve 19 can operate without difficulty as a return valve.
The type model example according to FIG. 4 is differentiated from that according to FIG. 3 essentially in such a way that the axial transmission channel 29 of the direct drive 1 is constructed as a so called bending tube or the like which is jointless, displacable, transmitting a torque moment connection and is joined to the hollow shaft 6 of the bearing block 7. The mode of action is, however, the same as in the case of the type model examples according to FIG. 3. During the flushing of the core sleeve 11 with flushing liquid with stop valves 32 and 19 open, the flushing liquid follows its flow path through the central transmission channel 29, the hollow shaft 6 of the bearing block 7, the connecting sleeve section 18 and the inlet channel 15 of the core sleeve 11 corresponding to the arrows 42 and 43 designated by solid lines. With stop valve 32 closed, the flushing liquid flowing out of the work space of the direct drive 1 enters through a return channel corresponding to the dash arrow designated by 44 in the hollow shaft 6 of the bearing block 7 flows through the connecting sleeve section 18 with storage device 23 which, in reaching the stated flushing pressure, releases the valve body 22 and lets it fall down on its valve seat 20 whereupon the flushing liquid enters through one or several connecting openings in the inlet channel corresponding to the arrow 45 designated by dashed lines out of the inlet channel 15 out and into the annular space 14.
While in the type model examples according to FIGS. 1 to 4 an arresting of the core sleeve 11 in drilling a core takes place with the latter through friction; in the type model example according to FIG. 5 for avoidance of any core damages a positive locking of the core sleeve 11 against a torque motion is provided. The direct drive 1 with its outside stator 2 and inside rotor 3 has again the central transmission channel 29 through which however in the FIG. 5 species a tubular extension 46 of the core sleeve 11 extends through. The extension 46 is screwed on to the upper end of the core sleeve 11 and extends out from the latter through the connecting sleeve section 18 containing the storage device 23 as well as through the hollow shaft 6 of the bearing block 7 and is led up with its end region extending through the direct drive 1 up to the lower end of the stationary drill pipe line. Here an attachment not further illustrated is undertaken of the upper end of the extension 46 to the stationary drill pipe line so that the core sleeve 11 is secured positively against every torque movement. At the same time the extension 46 forms a conducting channel for a central transmission of drill flushing through the direct drive 1.
The remaining construction parts of the type model example according to FIG. 5 correspond to those according to the type model examples according to FIGS. 1 to 4 and have on this basis the same reference symbols.
Up to the specified pressure in the flushing the upper stop valve 32 is open through which the central flushing of the core sleeve 11 takes place by way of extension 46 of it. The direct drive 1 again remains stationary. If the flushing pressure increases, then the upper stop valve 32 closes with the result that the flushing now flows through the work space of the direct drive 1 so that the latter operates. Therefore the flushing occurring from out of the work space of the direct drive 1 is deflected through side openings 47 in an annular space between the core sleeve extension 46 and the hollow shaft 6. Beneath the hollow shaft 6 is, in the core sleeve extension 46, a passage opening 49 for the flushing liquid so that the latter first of all again can enter into the extension 46 and in this way is led through the core sleeve 11 while at the same time a further portion of the flushing liquid flows through the connecting sleeve section 18 downward and through the bearing device 13 and therefore the annular space 14 between the outer sleeve 9 and the core sleeve 11. If the valve body 22 is in its closed position 22', then the flushing liquid is again conducted into the extension 46 at 49 through a side opening 50 out of the extension 46 and then flows likewise through the annular space 14. In the species according to FIG. 6, a modified arrangement is provided of the direct drive 1 in a manner the central body of which is constructed as a stator 51 and the outside body of which as a rotor 52. The stator 51 is connected by way of an upper universal shaft 53 with the lower stationary end of the drill pipe line. The lower end of the stator 52 is connected by an additional universal shaft 54 with the core sleeve unit 11, 12 and indeed having the sleeve section 12 connected to the inlet channel 15 which is screwed on to the core sleeve 11. In this manner the core sleeve 11 is held positively locked stationary in the outer sleeve 9 of the core drill device 8.
The rotor 52 forming the outer body of the direct drive 1 in this species is connected directly to the outer sleeve 9 of the core drill device 8.
The stator 51 again has in the center of the direct drive 1 the central transmission channel 29 on whose upper end the second stop valve 32 is located corresponding to the model types according to FIGS. 3 to 5, while the first stop valve 19 is constructed in the manner already explained with the aid of the previous type model examples in the inlet channel of the core sleeve 11.
During the flushing of the core sleeve 11 with the upper stop valve 32 open, the direct drive 1' remains still and the flushing liquid moves exclusively through the central transmission channel 29 as well as through the universal shaft 54 constructed as a hollow shaft to the core sleeve 11 and flows through the latter. If the upper valve 32 closes at increased pressure in the flushing medium, then the flushing medium passes into the work space of the direct drive 1' and after that arrives in an annular space 55 continuing upward into the annular space 14 between the outer sleeve 9 of the core drill device 8 and the universal shaft 54. There are one or several passage openings 56 through which the flushing medium is fed frm the annular space 55 into the hollow extension 54' of the universal shaft 54. The storage device 23 for the valve body 22 is above the passage 56. The flushing liquid flows before its entrance into the passage openings 56 into the annular space between the housing of the storage device 23 and the outer sleeve 9. The pressure difference resulting from this leads in an over stepping of the nominal valve to the downward motion to the storage device 23 whereby the valve body 22 is released and the stop valve 19 closes.
In the closing of the second stop valve 19, the flushing liquid 19 enters through the openings 56 and the sleeve section 12 and out through one or several side openings 58 above the stop valve 19 corresponding to the dashed line designated by the arrow 59 and arrives in the annular space 14 and therewith to the drill tip 10.
In the species according to FIG. 7 in place of the universal shafts 53 and 54 illustrated in FIG. 6, bending tubes 60 and 61 are provided for the connection to the central stator 51. In regard to the remaining construction parts the type model according to FIG. 6 is principally the same and corresponds also to it in the function particularly which concerns the positive arrangement of the core sleeve 11 and the guiding of the flushing liquid in the opened and closed stop valves 19 and 32.
FIG. 8 shows a type model example analogous to the type model according to FIG. 6 or FIG. 7. In the universal shaft 54 between the central stator 51 and the upper end of the core sleeve 11 or the sleeve section 12 having the inlet channel 15, are one or several passage openings 64 for the flushing medium and under it the first, lower stop valve 19 with the valve seat 20. The connection between the stator 51 and the hollow shaft 6 of the bearing block 7 designates a bending tube shaft 63 joined to the stator on the upper end, which also can be joined with the lower end of the stator according to FIG. 7. However, this connection can also consist of a universal shaft with a central hole. Above the stator 51 is the second stop valve 32 with its valve seat 33 which is constructed in the upper end region of the bending tube shaft 63.
Upstream of the stop valve 32 is a displaceable storage device 23 for the two valve bodies 22 and 34. The two valve bodies 22 and 34 have, in so doing, different diameters, in which the first, smaller valve body 22 is provided for the lower stop valve 19 and the second, larger valve body 34 for the upper stop valve 32 can be used analogous to the illustration according to FIG. 2 for example with other diametrically opposite recesses 24 for the valve bodies 22 or 34 in each case in which this duplicate design operates in a manner so that first of all the smaller valve body 22 by passes the valve seat 33 of the upper stop valve 32 and seats on the valve seat 20 of the lower stop valve, in so doing, the flushing of the core sleeve 11 is shut off.
In spite of this shut off the flushing liquid by passes a before the direct drive 1 through the bending tube shaft 63 forming the central transmission channel without in so doing an activity of the direct drive 1' taking place. If now the larger valve body 34 from the storage device 23' is released, then the central channel through the bending tube shaft 63 is completely shut off and the flushing liquid now flows into the work space of the direct drive 1' formed between the stator 51 and the rotor 52. After the flushing liquid has passed through the work space of the direct drive 1' it arrives by way of the flow through of the channels 56 and 64 into the annular space 14 between the outer sleeve 9 and the core sleeve 11 of the core drilling device 8 as the arrows 62 show while next only with the displaced, smaller valve body 22 on the valve seat 20 does the flushing liquid arrive through the hollow universal shaft 54 to the passage openings 64 in the annular space 14 by way of flowing around the bearing device 13. With valves 19 and 32 opened, the central flushing analogous to the species according to FIGS. 3 to 7 takes place.
For the species collectively, the species according to FIG. 1 excepted, in which no central transmission through the direct drive is provided, there is a possible modification in a manner such that the lower stop valve 19 and/or the upper stop valve 32 first of all are designed only as a simple valve seat. The valve body in each case can in these cases be formed by a well known insertion body which is inserted above ground in the flushing. The insertion body is then carried downward by the flushing, passes the direct drive and is seated on the lower or upper valve seat.
Since in a direct drive with a central transmission channel two stop valves must be present, as otherwise the work space of the direct drive for actuation of the core drill device 8 cannot be flowed through by the flushing liquid as the lower valve under the complete flushing pressure existing over the direct drive would be present, such a one can be withdrawn as a valve body the lower stop valve 19 from a storage device like the storage device 23 while the insert body inserted above ground in the flushing seats itself on the valve seat of the upper stop valve 32.
If the lower seat is exceeded in diameter by the valve seat for the upper valve, the possibility exists in addition to close off both stop valves by means of an insert body in which then the first insert body has to be the one for the lower stop valve with a smaller cross section. Such a design is structurally extraordinarily simple and functionally safe in so far that it is guaranteed that the service personnel adhere to a certain sequence series of the insert bodies. During this process there is a time delay between the insertion of the first and second insert body required in order to guarantee a specific sequence series and sure seating. This is achievable with the previously described type model in a mechanical way without influence by the service personnel.
In FIG. 9 a species corresponding to FIG. 8 is represented for illustrative purposes in which for the lower stop valve 19 an insert body 65 is provided in the shape of a ball valve and for the upper valve seat 32 an insert body 66 with an inserted cone as is illustrated in enlarged detail in FIG. 9. Moreover the type model according to FIG. 9 corresponds in its construction and in its mode of action to the type model according to FIG. 8.
The core drill devices illustrated in FIGS. 6 to 9 are uniformly illustrated with bearing devices 13 for the core sleeve 11 which, however, do not necessarily have to include axial bearing components through which in addition to an architectural simplification also a simpler flushing passage from the annular space 55 (FIG. 6) is achieved in the annular space 14.
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In a core drilling apparatus wherein a core bit is driven by a hydraulically actuated Moineau type motor, control valve means are provided whereby drilling fluid can be directed through the core sleeve to remove debris from its interior, and, subsequently diverted outside of the core sleeve when drilling begins. Alternative constructions are shown whereby the flushing of the core sleeve can be accomplished with the motor drive in an inactive mode or in an operating mode.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of U.S. application Ser. No. 11/163,366 filed Oct. 17, 2005 now abandoned.
BACKGROUND OF INVENTION
This invention relates to a composition for gas treatment to remove heavy metals, particularly mercury, from gas streams, particularly flue gas streams, and processes and systems for making and using the composition. In particular, the invention relates to a sorbent for removal of mercury from flue gas and processes and systems for making and using the sorbent.
In August 2000, the National Research Council completed a study that determined that the U.S. Environmental Protection Agency's (EPA) conservative exposure reference dose of 0.0001 mg mercury/kg body weight/day was scientifically justified to protect against harmful neurological effects during fetal development and early childhood. Subsequently, in December 2000, EPA announced its intention to regulate mercury and other air toxics emissions from coal- and oil-fired power plants. The pending regulation has created an impetus in the utility industry to find cost-effective solutions to meet the impending mercury emission standards.
Domestic coal-fired power plants emit a total of about fifty metric tons of mercury into the atmosphere annually—approximately one third of all anthropogenic mercury emissions in the U.S. A coal-fired utility boiler emits several mercury species, predominantly in the vapor-phase in boiler flue gas, including elemental mercury, and ionic mercury in mercuric chloride (HgCl.sub.2) and mercuric oxide (HgO)—in different proportions, depending on the characteristics of the coal being burned and on the combustion conditions.
Today, municipal solid waste (MSW) incinerators and medical waste combustors predominantly utilize the best commercially available control technology for reduction of mercury emissions: adsorption of mercury species onto activated carbon. Although fairly effective for MSW incinerators, activated carbon is a less appealing solution for coal-fired flue gas streams because of the dramatic difference in mercury concentrations. Regulations for mercury control from municipal and medical waste incinerators specify outlet emission levels of no more than fifty micrograms per cubic meter. In coal-fired flue gas streams, typical uncontrolled mercury concentrations are on the order of ten micrograms per cubic meter. Thus, reduction of mercury emissions from coal combustion flue gases presents a unique challenge in that the mercury is present in low concentrations in very large volumes of flue gas.
Fixed beds of zeolites and carbons have been proposed for a variety of mercury-control applications, but none has been developed specifically for control of mercury in coal combustion flue gas. Products in this class include Lurgi GmbH's (Frankfurt, Germany) Medisorbon and Calgon Carbon Corporation's (Pittsburgh, Pa.) HGR.
Calcium carbonate (limestone), calcium oxide (lime), and calcium hydroxide (slaked lime) are employed in flue gas desulfurization (FGD). Sulfur dioxide in flue gas reacts with these materials to yield solid calcium sulfite. It is known that some of the mercury in the flue gas is removed in the flue gas desulfurization processes employed by electric utilities, however the proportion of mercury removed falls short of the goals set by EPA. Some installed FGD systems allow relatively pure calcium sulfite to be oxidized to calcium sulfate (FGD Gypsum) which may be sold for use in wallboard. Unlike FGD gypsum, which can be sold, most power plants have to pay to dispose of sulfite-rich scrubber material. Out of 18 million tons of sulfite-rich scrubber material produced by coal-burning power plants in 2000, 3 million tons were disposed of as wet by-product, 12 million tons were disposed of in landfills as dry by-product, and only 1 million tons were used for any meaningful purpose at coal-burning electric utility sites. This material presents environmental challenges due to concerns associated with long-term impacts of calcium-sulfite landfills. A beneficial use for FGD calcium sulfite-rich by-product, which is often admixed with varying amounts of unreacted calcium carbonate, oxide, or hydroxide, as well as coal combustion ash, is being sought by coal-burning electric utilities.
At present, the injection of activated carbon is generally considered to be the best available demonstrated control technology for reduction of mercury emissions from coal-fired power plants that do not have wet scrubbers (about seventy-five percent of all such plants in the U.S.). Tests of carbon injection, both activated and chemically impregnated, have been reported in the technical literature. In order to achieve EPA's goal of removing 90% of the low mercury concentrations found in coal combustion flue gases, projected injection rates for activated carbon are on the order of 10,000 to more than 20,000 pounds of activated carbon for each pound of mercury removed, depending on the physical characteristics of the activated carbon, and the concentration and speciation of mercury in the flue-gas. The cost to implement effective activated carbon mercury control systems has been estimated by the U.S. Department of Energy (DOE) to be on the order of US$60,000 per pound of mercury removed.
Activated carbon injection rates for effective mercury control at different facilities have been found to be widely variable and are explained by the dependence of the sorption process on flue gas temperature and composition, efficiency of dispersion of the activated carbon throughout the flue gas stream, mercury speciation and also on fly ash chemistry. When employed for mercury control, some of the carbon becomes part of the ash collected by particulate-control devices and would be expected to make the fly ash unsuitable for incorporation into concrete. This impact on the marketability of collected fly ash can substantially increase the effective cost of mercury control for a coal-fired power plant, and more of this major coal combustion by-product would become a waste to occupy landfill space.
In addition to the economic drawbacks presented by the use of activated carbon sorbent for mercury control, technical viability issues remain to be resolved. Coal-fired combustion flue gas streams include trace amounts of acid gases, including SO.sub.2, NO and NO.sub.2, and HCl. This mix of acid gases has been shown to degrade the performance of some of the chemically treated activated carbons and other sorbents such as noble-metal-impregnated alumina.
Regenerable sorbents with an initial cost roughly equivalent to activated carbon have been developed with the aim of reducing the overall cost of mercury removal through recycle of the sorbent. These sorbents employ a phyllosilicate mineral substrate and precipitate a polyvalent sulfide from aqueous solution onto the mineral's surface in a multistep aqueous process (U.S. Pat. No. 6,719,828 to Lovell et al.). Collecting and processing such a sorbent to regenerate such a fine particulate material would be expected to present significant unresolved challenges for the typical coal-fired power plant.
While micro-porosity is a critical characteristic of an efficient sorbent for mercury from flue gases, mass transfer of gaseous mercury by diffusion from the bulk flue gas to the solid surface can limit capture of mercury; diffusion within a porous sorbent is not believed to be rate-limiting (Status review of mercury control options for coal-fired power plants; John H. Pavlish, et al.; Energy and Environmental Research Center; 2003). Reducing the size of the sorbent particles and increasing their dispersion in the gas stream enhances control, but large quantities of sorbent are required in all instances. Pavlish et al. found that to achieve 90% mercury removal in 2 seconds residence time by activated carbon injection required a minimum carbon-to-mercury mass ratio of about 3,000:1 for 4 micron particles and about 18,000:1 for 10 micron particles. Assuming constant density for the carbon particles and more spherical particles as the particle size decreases, the data of Pavlish et al. indicate that approximately the same number of 10 micron particles or 4 micron particles are required to achieve the 90% mercury removal. Chemical treatments to enhance the ability of activated carbon and micro-porous mineral substrates to adsorb and fix mercury increase the cost per pound of sorbent, thus substantially increasing the cost of overcoming this mass transfer limitation. An effective sorbent with a cost far below the cost for activated carbon is needed to allow the necessary large number of particulates to be dispersed within the flue gas stream to cost-effectively overcome this mass transfer by diffusion limitation.
Thus a pressing need exists for a mercury sorbent which is capable of being dispersed in a coal combustion flue gas stream as very small particulates, is capable of adsorbing both elemental and ionic mercury species, is substantially less expensive than activated carbon, and has characteristics which allow it to be incorporated into concrete along with coal combustion ash. A preferred embodiment of the present invention utilizes calcium sulfite-rich FGD by-product material for the production of an effective low-cost calcium sulfide-rich mercury sorbent.
U.S. Pat. No. 4,193,811 to Ferm teaches that alkaline earth metal polysulfides, particularly calcium polysulfide, are beneficial additives to concrete in that they act as strength enhancers.
U.S. Pat. No. 3,194,629 to Dreibelbis et al. discloses impregnation of activated carbon with elemental sulfur as a sorbent for removing mercury from gases.
U.S. Pat. No. 3,873,581 to Fitzpatrick et al. discloses a process for reducing the level of contaminating mercury in aqueous solutions. The process is applied to aqueous solutions and not to gases and it relies on treating an adsorbent with a mercury-reactive factor. Disclosed absorbents are titania, alumina, silica, ferric oxide, stannic oxide, magnesium oxide, kaolin, carbon, calcium sulfate, activated charcoal, activated carbon, activated alumina, activated clay or diatomaceous earth.
U.S. Pat. No. 4,069,140 to Wunderlich discloses a method for removing arsenic or selenium from a synthetic hydrocarbon fluid by use of a contaminant-removing material. The contaminant-removing material comprises a carrier material and an active material. Carrier materials are selected from the group consisting of silica, alumina, magnesia, zirconia, thoria, zinc oxide, chromium oxide, clay, kieselguhr, fuller's earth, pumice, bauxite and combinations thereof. The active material is selected from the group consisting of iron, cobalt, nickel, at least one oxide of these metals, at least one sulfide of these metals, and combinations thereof.
U.S. Pat. No. 4,094,777 to Sugier et al. discloses a process for removing mercury from a gas or liquid. It teaches impregnation of a support only with copper and silver, although other metals can be present, for example iron. The supports taught are limited to silica, alumina, silica-alumina, silicates, aluminates and silico-aluminates; and incorporation of both metal(s) and pore-forming materials during production of the supports is taught to be necessary. Only relatively large adsorption masses are envisioned, e.g., alumina balls. Only a fixed bed reactor is taught for contacting the gas with the absorption masses, as would be appropriate for natural gas or electrolytic hydrogen decontamination, which are the only disclosed uses of the compositions and process.
U.S. Pat. No. 4,101,631 to Ambrosini et al. discloses a process for selective adsorption of mercury from a gas stream. This invention involves loading a natural or synthetic zeolite molecular sieve with elemental sulfur before the zeolite molecular sieve is contacted with the gas stream. Metal sulfides are not present in the zeolite molecular sieve when it is contacted with the gas stream. The use of pellets in adsorption beds is disclosed.
U.S. Pat. No. 4,233,274 to Allgulin discloses a method for extracting and recovering mercury from a gas. The invention requires that the gas be contacted with a solution containing mercury (II) ions and ions with the ability to form soluble complexes with such ions.
U.S. Pat. No. 4,474,896 to Chao discloses adsorbent compositions for the adsorption of mercury from hydrocarbon gas streams. Disclosed support materials are limited to carbons, activated carbons, ion-exchange resins, diatomaceous earths, metal oxides, silicates, aluminas, and aluminosilicates, with the most preferred support materials being ion-exchange resins and crystalline aluminosilicate zeolites that undergo a high level of ion-exchange. The adsorbent compositions are required to contain polysulfide species, while sulfide species may optionally also be present. Metal cations appropriate for ion-exchange or impregnation into the support material are taught to be antimony, arsenic, bismuth, cadmium, cobalt, copper, gold, indium, iron, iridium, lead, manganese, molybdenum, mercury, nickel, platinum, silver, tin, tungsten, titanium, vanadium, zinc, zirconium and mixtures thereof derived from carboxylic acids, nitrates and sulfates. The only forms of adsorbent compositions disclosed are 1/16-inch pellets.
U.S. Pat. No. 4,721,582 to Nelson discloses a composition comprising water-laden, exfoliated vermiculite that is coated with magnesium oxide for use as a toxic gas adsorbent and processes for making the same.
U.S. Pat. No. 4,814,152 to Yan discloses a composition and process for removing mercury vapor. The composition comprises a solid support that is limited to a carbonaceous support such as activated carbon and activated coke, and refractory oxides such as silicas, aluminas, aluminosilicates, e.g., zeolites. The solid support is impregnated with elemental sulfur.
U.S. Pat. No. 4,834,953 to Audeh discloses a process for removing residual mercury from treated natural gas. The process is limited to contacting the gas first with an aqueous polysulfide solution and then with a soluble cobalt salt on a non-reactive carrier material such as alumina, calcium sulfate, or silica.
U.S. Pat. No. 4,843,102 to Horton discloses a process for removal of mercury from gases with an anion exchange resin. The invention is limited in that the anion exchange resin is saturated with a polysulfide solution.
U.S. Pat. No. 4,877,515 to Audeh discloses the use of molecular sieves (zeolites) pretreated with an alkali polysulfide to remove mercury from liquefied hydrocarbons. U.S. Pat. No. 4,902,662 to Toulhoat et al. discloses processes for preparing and regenerating a copper-containing, mercury-collecting mass. The mass is made by combining a solid inorganic carrier, a polysulfide and a copper compound. Appropriate solid inorganic carriers are limited to coal, active carbon, coke, silica, silica carbide, silica gel, natural or synthetic silicates, clays, diatomaceous earths, fullers earth, kaolin, bauxite, a refractory inorganic oxide such as alumina, titanium oxide, zirconia, magnesia, silicoaluminas, silicomagnesias and silicozirconias, alumina-boron oxide mixtures, aluminates, silicoaluminates, aluminosilicate crystalline zeolites, mazzites, and cements. U.S. Pat. No. 4,911,825 to Roussel et al. discloses a process for elimination of mercury and possibly arsenic in hydrocarbons. The invention requires that a mixture of the hydrocarbon and hydrogen be contacted with a catalyst, preferably deposited on a support chosen from alumina, silicoaluminas, silica, zeolites, active carbon, clays and alumina cements, and containing at least one metal from the group consisting of iron, cobalt, nickel and palladium. Contact with the catalyst is followed by contact with a capture mass including sulfur or a metal sulfide.
U.S. Pat. No. 4,962,276 to Yan discloses a process for removing mercury from water or hydrocarbon condensate using a stripping gas. The invention is limited to the use of a polysulfide scrubbing solution for removing the mercury from the stripping gas.
U.S. Pat. No. 4,985,389 to Audeh discloses polysulfide-treated molecular sieves and the use thereof to remove mercury from liquefied hydrocarbons. The molecular sieves are limited to calcined zeolites.
U.S. Pat. No. 5,120,515 to Audeh et al. discloses a method for dehydration and removal of residual impurities from gaseous hydrocarbons. The method is limited to replacing an inert protective layer on a pellet with an active compound comprising at least one of copper hydroxide, copper oxide and copper sulfide. Materials for the pellet are limited to alumina, silicoaluminas, molecular sieves, silica gels and combinations thereof.
U.S. Pat. No. 5,245,106 to Cameron et al. discloses a method for eliminating mercury or arsenic from a fluid. The process is limited to the incorporation of a copper compound into a solid mineral support, possible calcination of the impregnated support, contact of the impregnated support with elemental sulfur and heat treatment. The solid mineral supports are limited to the group formed by carbon, activated carbon, coke, silica, silicon carbide, silica gel, synthetic or natural silicates, clays, diatomaceous earths, fullers earths, kaolin, bauxite, inorganic refractory oxides such as for example alumina, titanium oxide, zirconium, magnesium, aliminosilicates, silicomagnesia and silicozirconia, mixtures of alumina and boron oxide, the aluminates, silicoaluminates, the crystalline, synthetic or natural zeolitic aluminosilicates, mazzites and cements.
U.S. Pat. No. 5,248,488 to Yan discloses a method for removing mercury from natural gas. The method is limited to contacting the natural gas with a sorbent material such as silica, alumina, silicoalumina or activated carbon having deposited on the surfaces thereof an active form of elemental sulfur or sulfur-containing material.
U.S. Pat. No. 5,695,726 to Lerner discloses a process for removal of mercury and cadmium and their compounds from incinerator flue gas. The invention is limited to contacting a gas containing HCl with a dry alkaline material and a sorbent followed by solids separation. Activated carbon, fuller's earth, bentonite and montmorillonite clays are disclosed as sorbents having an affinity for mercuric chloride.
U.S. Pat. No. 5,846,434 to Seaman et al. discloses an in-situ groundwater remediation process. The process is limited to mobilizing metal oxide colloids with a surfactant and capturing the colloids on a phyllosilicate clay.
U.S. Pat. No. 6,719,828 to Lovell et al. teaches preparation of mercury sorbents composed of polyvalent metal sulfides precipitated from aqueous solution onto a finely divided phyllosilicate substrate in a multi-step process. The estimated manufactured cost for these sorbents is stated to be about $0.50 per pound of sorbent, compared to $0.55 per pound for activated carbon, but the sorbents are taught to be recyclable.
U.S. Pat. No. 5,653,955 to Wheelock teaches regeneration of calcium oxide used to remove hydrogen sulfide from the gases resulting from coal gasification processes. Cyclic oxidation and reduction are taught to overcome the formation of an impermeable layer of calcium sulfate on the surface of calcium sulfide particles formed by reaction of hydrogen sulfide gas with calcium oxide particles. Calcium oxide and sulfur dioxide are the products of the process taught.
No individual background art reference or combination of references teach or anticipate the compositions, processes and systems disclosed herein.
SUMMARY OF INVENTION
The purpose of this invention is to provide compositions, processes and systems for removal of heavy metals, particularly mercury, from gas streams. This invention is particularly directed to removal of mercury from flue gases resulting from the combustion of coal.
Unique micro-porous particulates composed at least partially of metal sulfides result from the chemical reduction of materials composed at least partially of the corresponding metal sulfates or metal sulfites at elevated temperatures in the range from about 900 degrees C. to about 1100 degrees C. These metal sulfide containing particulates have been found to exhibit unique and highly desirable physical characteristics to enable their use as sorbents and substrates for other sorbents to remove heavy metals, particularly mercury, from coal combustion flue gases.
Metal sulfides, particularly polyvalent metal sulfides, have heretofore been available as sorbents for mercury only in the form of monomolecular layers applied with difficulty to various micro-porous substrates such as activated carbon, or phyllosilicates such as vermiculite, because said metal sulfides have heretofore been available only in the form of dense, non-porous particulates unsuitable for use as sorbents. The process of the present invention yields metal sulfides, particularly polyvalent metal sulfides, more particularly transition metal and alkaline earth metal sulfides, and most particularly alkaline earth metal sulfides, having a physical form suitable for use directly as sorbents for heavy metals, particularly mercury, from gas streams.
A novel method of preparing a micro-porous polyvalent metal sulfide for use as a mercury sorbent is taught herein. The micro-porous metal sulfide containing particulates disclosed herein can be readily admixed with liquid or gaseous sulfur, metal polysulfides, and other metal salts, particularly transition metal halide salts, to produce efficient heavy metal sorbents, particularly mercury sorbents, tailored for use in coal combustion flue gases at different temperatures and containing differing levels and compositions of acid gases, and differing mercury speciation.
DETAILED DESCRIPTION
It has been discovered that novel micro-porous sorbent particulates composed at least partially of one or more metal sulfides are produced by the chemical reduction of one or more metal sulfates or one or more metal sulfites to the corresponding metal sulfides by employing a gaseous reductant at temperatures above about 900 degrees C., but below the melting temperatures of said metal sulfates, metal sulfites, and metal sulfides. These particulates act as sorbents for heavy metals, particularly mercury, when these micro-porous particulates are contacted with mercury-containing gases, particularly coal combustion flue gases. The unique micro-porous sorbent particulate morphology of the product of the present invention results from the high temperature reduction process integral to the process of the present invention. While not wishing to be limited by theory, it is believed that, in the process of the present invention, chemical reduction is accomplished by the diffusion of a reducing gas into solid particulates and the outward diffusion of a resulting oxidized gas species. The kinetics of this chemical reduction can be characterized by what is referred to as the “shrinking core reaction model”. Reduction of metal sulfates, metal sulfites, or a combination thereof, to metal sulfides is most preferably carried out by employing carbon as the source of carbon monoxide gaseous reductant. Reduction occurs when carbon monoxide gas diffuses into solid particulates initially composed predominantly of metal sulfate or metal sulfite. Carbon monoxide is oxidized to carbon dioxide within the particulates containing metal sulfate or metal sulfite as the metal sulfate or metal sulfite is reduced to the corresponding metal sulfide. As the reaction proceeds carbon dioxide diffuses out of these solid particulates while carbon monoxide continues to diffuse into these same particulates which are developing substantial micro-porosity as large sulfate or sulfite ions in particulates' crystalline lattice are replaced by smaller sulfide ions, thus a micro-porous particulate structure results. Formation of the unique micro-porous sorbent particulate structure disclosed herein allows metal sulfides formed by the high temperature reduction of metal sulfates, metal sulfites, or a combination thereof, to be employed directly as sorbents and sorbent substrates for the removal of mercury from gas streams.
The micro-porous particulates of the present invention are preferably particulates containing calcium sulfide produced by the thermal reduction of calcium sulfite or calcium sulfate flue gas desulfurization by-products. Thus, a by-product existing at coal burning utilities can be employed as the raw material for a process to produce a much-needed economical sorbent for mercury removal from coal combustion flue gas. The coal combustion fly ash usually present as a component of flue gas desulfurization by-products does not have a detrimental effect on the use of sulfate-rich or sulfite-rich flue gas desulfurization by-products in the process of the present invention.
The metal sulfides of the invention disclosed herein act as effective substrates, as well as efficient sorbents, because of the unique micro-porosity in the metal sulfide particulates resulting from the reduction process employed to produce them. Polyvalent metal salts, particularly nitrates and chlorides, and sulfur can be employed to coat and chemically modify the surfaces in the interstices of the particulates of the present invention. While not wishing to be limited by theory, applicants believe that this micro-porosity is the result of the voids created as large sulfate or sulfite ions are replaced by sulfide ions within a solid particulate structure by means of the high temperature reduction process inherent in the process of the present invention. Only metal sulfides having a melting temperature higher than the 900 degrees C. to 1100 degrees C. chemical reduction reaction temperature will retain the unique micro-porous structure inherent in the product of the present invention. Thus, strontium sulfide, an alkaline earth metal sulfide, with a melting point above 2000 degrees C. retains the desired micro-porous structure. Calcium sulfide, another alkaline earth metal sulfide, has also been found to retain the micro-porous structure integral to the product of the present invention. Iron (II) sulfide, with a melting point of about 1171 degrees C., will retain the micro-porous structure inherent in the products of the present invention unless impurities are present which act as “mineralizers”, that is, which act to reduce the temperature at which a liquid phase appears. To facilitate the process of high temperature reduction, it is highly desirable that the metal sulfates and metal sulfites subjected to the process of the present invention also remain solids at the high temperatures required to reduce sulfate and sulfite ions to sulfide ions using the reducing agents taught herein. In general, sulfates, sulfites, and sulfides of most polyvalent metals have very high melting temperatures and are suitable for the process of the present invention.
Thermal reduction is preferably accomplished in a high temperature countercurrent rotary kiln utilizing, as the reductant, coal or coke having a high fixed carbon content, i.e. a low volatile carbon content. Other types of thermal reduction process equipment are known to those skilled in the art; these may employ gaseous reductants such as carbon monoxide, hydrogen, and natural gas in equipment such as fluidized bed reactors.
In a high temperature countercurrent rotary kiln employing carbon as the reductant at temperatures in excess of about 900 degrees C., carbon monoxide gas is believed to react with sulfate and sulfite ions on or within solid particulates to remove oxygen from these ions and form carbon dioxide. The carbon dioxide diffuses out of these solid particulates, encounters solid carbon particles, reacts with the elemental carbon present to regenerate carbon monoxide, and thus perpetuates the reaction to allow further reduction of sulfate and sulfite ions to sulfide ions. Carbon monoxide must rapidly diffuse into the interior of a particulate to react to form carbon dioxide which must rapidly diffuse out of that particulate, thus particulate porosity is a requirement for the chemical reaction producing metal sulfide to proceed. Barium and strontium sulfide particulate materials are commercially produced by the thermal reduction of naturally-occurring barium sulfate and strontium sulfate ores reduced in size to granules passing through a U.S. Standard 14 mesh sieve. Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Volume 3, page 913 states that for reduction of barium sulfate to barium sulfide, reaction completion is approached in less than 10 minutes at 1100 degrees C.; only a granule exhibiting substantial porosity in the portion of the granule containing the barium sulfide reaction product could accommodate sufficient gaseous diffusion, both into and out of the granule, to effect reaction completion in this short time.
The micro-porous metal sulfide containing particulates of the present invention can be employed as an inexpensive substrate for polyvalent metal ions, chloride ions, polysulfides, and elemental sulfur. Thus, the sorbent of the present invention can be optimized for any of the myriad flue gases resulting from combustion of different grades of coal and coals containing different impurities. In addition to elemental sulfur, polysulfide ions, and chloride ions, the following polyvalent metal ions, alone or in combination, can be incorporated into the micro-porous product of the present invention to promote mercury removal from gas streams: antimony, arsenic, bismuth, cadmium, cobalt, copper, gold, indium, iron, lead, manganese, molybdenum, mercury, nickel, platinum, silver, tin, tungsten, titanium, vanadium, zinc, and zirconium.
Mineral species including, but not limited to, phyllosilicates, kaolin clays, sepiolite, bentonite, vermiculite, and pearlite can be present as impurities in, or intentionally added to, the metal sulfate or metal sulfite containing material subjected to high temperature reduction without departing from the spirit of this invention. Mineral species including, but not limited to, phyllosilicates, kaolin clays, sepiolite, bentonite, vermiculite, and pearlite can be intentionally added to the micro-porous particulate composed at least partially of metal sulfide disclosed herein without departing from the spirit of this invention.
One advantage of the present invention is that the compositions (sorbents) disclosed herein can be cost-effectively employed in sufficient quantity in a gas stream to overcome the capture limitation imposed by the rate of mass transfer of gaseous mercury by diffusion from the bulk flue gas to the solid surface. Another advantage is that the disclosed sorbents are only minimally affected by typical acidic flue gases due to the micro-porous structure of the metal sulfide containing particulates embodied in this invention. A further advantage is that costly sorbent chemical components can be deployed into flue gases as molecularly thin films by utilizing the micro-porous particulates of the present invention as an inexpensive support substrate. In addition to having sorption characteristics that are comparable to commercial activated carbons for both elemental and oxidized mercury, the sorbents disclosed herein are substantially less expensive than activated carbon and do not adversely impact the value of coal combustion by-product fly ash by limiting its use as a concrete additive. Preferred forms of the sorbents disclosed herein ensure that they are “drop-in” replacements for carbon technology and do not require any additional technologies for injection, or collection. The improved capacity and efficiency, and the lower costs for the herein disclosed technology, promise to substantially reduce the costs of implementing mercury emissions controls on coal-burning electric power plants, benefiting both the utility industry and the U.S. public.
In most flue gas treatment systems, the contact time of a mercury sorbent with a mercury-containing gas is of very brief duration, on the order of about 2 seconds. Therefore, small particle size to promote dispersion of the sorbent in the flue gas is as important as the porosity of the individual sorbent particles. Surfaces closest to the bulk flue gas will probably perform the majority of the sorption. The metal sulfide micro-porous particulates of the present invention provide a reactive metal sulfide either as the primary reactive component or as a substrate for other reactive components, which are not required to be present as a continuous surface layer on the underlying metal sulfide.
Specific polyvalent metal sulfide reactants may be desired to enhance the performance of the product of the present invention in particular flue gas steams. Polyvalent metal ions can be easily precipitated onto the surface of the micro-porous particulates of the present invention by addition of relatively small amounts of concentrated aqueous chloride solutions of the desired polyvalent metal, thus ensuring that all of the specifically added polyvalent metal ions engage in the sorption process.
The disclosed invention is expected to greatly reduce the cost of mercury control by decreasing the overall cost of sorbent injected, and reducing costs for handling and disposing of spent sorbent. The formulation of the sorbents disclosed herein also results in stronger bonding of the mercury to the chemical amendment of the substrate material. The mercury present on used sorbent is thus more difficult to remove, resulting in a final waste form that is more stable and less likely to return the captured mercury to the environment via leaching or other natural processes after disposal.
One object of the invention is to reduce the cost and increase the effectiveness of mercury sorbents and to increase the cost effectiveness of methods and systems for removing mercury from flue gases. Another object of the invention is to prevent contamination of fly ash with activated carbon, thus facilitating continued beneficial use of this material as a component of concrete.
In a preferred embodiment, this invention is concerned with a process for preparing a solid sorbent and product prepared therefrom. The preferred multi-step process includes the steps of (1) subjecting an alkaline earth metal sulfite-rich or an alkaline earth metal sulfate-rich material to high temperature reduction utilizing coal or coke as the reductant to yield a light, ash-like, micro-porous alkaline earth metal sulfide-rich reactive substrate particulate, (2) admixing this reactive substrate particulate with elemental sulfur at a temperature above the melting temperature of elemental sulfur, and most preferably at a temperature above the boiling temperature of elemental sulfur, to incorporate elemental sulfur and polysulfide ions into the micro-porous alkaline earth metal sulfide-rich particulate, (3) grinding the admixture from step (2) to reduce aggregates to a size below about 20 microns in diameter. The high capacity sorbent resulting from this multi-step process is suitable for incorporation into concrete as a component of fly ash after it has been utilized for the removal of mercury from a coal combustion flue gas by injection and dispersion into the flue gas stream.
The sorbent of the present invention is preferably employed to capture elemental mercury or oxidized mercury species (mercuric chloride) from flue gas and other gases at temperatures from ambient to about 200 degrees C. A fixed bed may be employed, or the sorbent may be injected directly into the gas stream.
In a most preferred embodiment, dry coal combustion flue gas desulfurization calcium sulfite-rich by-product composed of particulates having cores of calcium oxide, calcium hydroxide, or calcium carbonate is admixed with coal or coke in the ratio of about 0.15 pounds of carbon for each pound of calcium sulfite contained in the flue gas desulfurization by-product. This admixture is subjected to temperatures in excess of about 900 degrees C. in a counter-current rotary kiln in a reducing environment to form micro-porous particulates composed at least partially of calcium sulfide, carbon dioxide, and carbon monoxide. The resulting particulates composed at least partially of calcium sulfide are admixed with elemental sulfur and the admixture is heated to a temperature above about 444 degrees C., the boiling temperature of elemental sulfur at atmospheric pressure. The admixture is then subjected to grinding to reduce the particulates constituting the admixture to a size of less than about 20 microns to yield a sorbent for mercury removal from flue gas.
ILLUSTRATIVE EXAMPLE
Strontium, one of the alkaline earth metals, occurs in nature primarily as strontium sulfate, the mineral celestite. Celestite rocks, typically containing about 90% strontium sulfate by weight and about 7% calcium carbonate as the principal impurity, are ground to yield coarse particles.
Ground celestite is admixed with powdered petroleum coke in the ratio of about 0.18 pounds of petroleum coke for each pound of ground celestite. This admixture is introduced into a countercurrent rotary kiln at the opposite end from the external source of heat, an oil or gas fired burner. The average residence time of the admixture in the rotary kiln is about 2 hours. Air intrusion into the kiln is restricted so that there is no free oxygen inside the rotary kiln. As the celestite and coke admixture moves through the rotary kiln, the admixture reaches a temperature of about 1050 degrees C. Exothermic chemical reactions occur in the rotary kiln, but the celestite and coke admixture remains as a bed of solid particulates as it moves through the rotary kiln.
The appearance of the admixture when it is discharged from the rotary kiln is that of a fine, light ash and chemical analysis reveals that about 90% of the strontium sulfate that entered the rotary kiln has been converted to strontium sulfide. Elemental sulfur is added to the admixture after it has been discharged from the rotary kiln while the admixture is still at a temperature above about 500 degrees C.; 0.20 pounds of sulfur is added for each pound of celestite ore added to the kiln. After the sulfur-containing admixture has cooled to a temperature below about 100 degrees C., aggregates within the ash-like material exiting the rotary kiln are ground to a particle size below about 20 microns. This fine particulate sulfur-containing admixture, when dispersed in a mercury-containing flue gas, will sorb at least some of the mercury in the flue gas stream.
The mercury sorbents of the present invention could be injected while mixed in with sorbents for other flue gas components, such as calcium or magnesium hydroxide or oxide for flue gas desulfurization, rather than injected alone. Other variations of the methods of applying this invention can be formulated by those familiar with the art and they should be considered within the scope of this disclosure and the included claims.
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Systems are disclosed for making and using micro-porous particulates at least partially composed of metal sulfides, particularly alkaline earth metal and transition metal sulfides, as sorbents for removal of mercury from flue gas. Calcium sulfide micro-porous powders derived from the high temperature reduction of calcium sulfate and calcium sulfite are disclosed to be reactive substrates for a group of sorbents for adsorption of mercury from coal combustion flue gases produced by the utilities industry, as well as from natural gas and gaseous and liquid hydrocarbons. The sorbents are useful for cost-effectively adsorbing elemental mercury and oxidized mercury species such as mercuric chloride from flue gases, including those containing acid gases (e.g., SO.sub.2, NO and NO.sub.2, and HCl), over a wide range of temperatures.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/171,107, filed Apr. 21, 2009, the entire disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to support equipment adapted for use by athletes, such as football players, motor sports participants, such auto racing, and/or military, such as fighter pilots, in conjunction with shoulder pads and helmets for opposing hyperextension, whiplash head movement, and/or axial compressive forces.
BACKGROUND OF THE INVENTION
[0003] Athletes participating in severe contact sports, such as American football, are subject to exposure to hyperextension, whiplash-type head movement, and axial cervical compressive forces. Players at positions such as interior lineman, for example, are subjected to physical contact on virtually every play which can force the player's head rapidly backward to create a whiplash effect which can result in serious and disabling injury. Moreover, persons involved in activities such as high speed vehicle test piloting and race car driving can also be exposed to hyperextension or whiplash-type injuries caused by high rates of acceleration and impact forces.
[0004] Several types of helmet restrictors have been developed for athletes participating in severe contact sports such as football wherein the player's helmet, for example, is interconnected with a set of shoulder pads, or other support structure worn on the shoulders, by a brace which restricts backward movement of the helmet.
[0005] However, these devices also severely limit rotational or side-to-side movement of the head, which restriction is usually unwanted by the player and may interfere with play execution as a result of the limitations on head movement.
[0006] Yet another type of conventional protective device used by football athletes, in particular, comprises a cushion-like collar which is attached to the shoulder pads and substantially encircles the neck between the helmet and the pads. Again, that type of collar is uncomfortable and limits head movement in directions which the player may wish to make. Such types of collars also tend to sometimes exert a choking effect on the wearer when severely deflected or purposely or inadvertently grabbed by another player during play action. Moreover, some conventional restraint devices have also been constructed in a manner which does not adequately take advantage of the load reacting and distributing capability of the largest structure worn by a football player, namely the shoulder pad assembly. The limitations of conventional devices noted herein, as well as others recognizable to those skilled in the art, have been substantially overcome by the protective helmet support and movement restrictor of the present invention.
SUMMARY OF THE INVENTION
[0007] In all of the above-mentioned activities, it is desirable to minimize the chance of hyperextension or whiplash injury while also minimizing unwanted restriction to movement of the head. In other words, in the case of football athletes, protection against rearward hyperextension or whiplash-type injury is highly desired, but the player also does not want to have head movement restricted such as by attachment of any device to the helmet or to protective gear such as shoulder pads which will restrict turning of the head, side-to-side movement of the head, or even forward movement of the head when desired. At the same time, however, it is desirable to provide protective means which is capable of restricting rearward movement of the head and particularly rapid or whiplash-type movement. Moreover, the protective device should be able to distribute the forces between the protective device and the helmet and between the protective device and structure attached to the body to minimize discomfort or prevent injury to the wearer of the protective device at some other point.
[0008] Still further, the operating environment of protective devices, particularly for football players, is such that it is desirable to be able to replace at least a part of the protective device which comes in contact with the helmet after repeated exposure to perspiration, rain, snow and mud, for example. There is a continuing interest in providing improvements for use by persons requiring head protection, which will make the play of the game safer without unduly restricting normal head movement.
[0009] One or more embodiments of the present invention provide a unique helmet support and movement restrictor particularly adapted to be used in conjunction with shoulder pads for football players, motor sports drivers, pilots and the like.
[0010] In accordance with one or more aspects of the present invention, a helmet and shoulder pads with a magnetic movement restrictor is provided which limits movement of the helmet in a rearward whiplash direction as well as an axial compressive direction without restricting desired side-to-side or turning movement of the helmet. The arrangement of the helmet magnets and shoulder pad magnets is such as to avoid contact with the wearer's head and neck during normal activity while instead engaging the magnets and being capable of substantial cushioning action and rearward movement restriction in the event of backward hyperextension or whiplash-type movement or axial compression of the helmet.
[0011] In accordance with one or more further aspects of the present invention, a magnetic helmet support and movement restrictor is provided which is particularly adapted to be used in conjunction with a set of football shoulder pads wherein a cooperative force distributing and reacting effect between the shoulder pads, body arches or chest and back plates and the helmet movement restrictor is obtained.
[0012] In accordance with one or more further aspects of the present invention, a magnetic helmet support for attachment to a helmet and magnetic movement restrictor for attachment to shoulder pads are provided which may be easily retrofitted to existing shoulder pads and helmets or may be supplied with new shoulder pads when manufactured. The helmet support and movement restrictor advantageously utilizes a uniquely configured set of magnets for supporting a set of opposing magnets on the helmet. The opposing magnets create an invisible cushion between the helmet and shoulder pads which does not restrict side-to-side movement or turning.
[0013] In accordance with one or more embodiments of the present invention, an apparatus includes: a helmet sized and shaped to receive and protect a user's head from injury; a shoulder pad assembly sized and shaped to receive and protect the user's shoulders; a first housing coupled to the helmet and including at least one first magnet; and a second housing coupled to the shoulder pad assembly and including at least one second magnet. The first and second magnets are oriented within the respective first and second housings such that, when the helmet and the shoulder pad assembly are worn by the user, there is resistance to movement of the first and second housings toward one another.
[0014] Preferably, each of the first and second magnets includes north and south poles. The first and second magnets are preferably oriented within the respective first and second housings such that either the respective north poles thereof or the respective south poles thereof are directed toward one another to produce a magnetic opposing force, which produces the resistance to movement.
[0015] The helmet may include at least one peripheral edge at least partially circumscribing an opening for receiving the user's head. The first housing may be located at a lower, rear portion of the peripheral edge of the helmet. Alternatively or additionally, the shoulder pad assembly may include at least one peripheral edge at least partially circumscribing an opening through which the user's neck extends. The second housing may be located at a rear portion of the peripheral edge of the shoulder pad assembly.
[0016] The first and second magnets may be are oriented within the respective first and second housings, and the first and second housings may be oriented on the helmet and shoulder pad assembly, respectively, such that, when the helmet and the shoulder pad assembly are worn by the user, the opposing force and resistance to movement restrict rearward hypertension and whiplash movement of the user's head and neck. Additionally or alternatively, such orientations may produce the opposing force and resistance to movement in order to restrict axial compression of the user's neck.
[0017] The first housing may include a plurality of magnets constituting the at least one first magnet and forming a first array of magnets. Additionally or alternatively, the second housing may include a plurality of magnets constituting the at least one second magnet and forming a second array of magnets. The magnets of the first and/or second arrays of magnets include north and south poles, and the first and second arrays of magnets may be oriented within the respective first and second housings such that either the respective north poles of the respective pluralities of magnets, or the respective south poles of the respective pluralities of magnets, are directed toward one another to produce a magnetic opposing force, which produces the resistance to movement.
[0018] The first array of magnets may be oriented in a semi-circular pattern when viewed along respective polar axes of the plurality of magnets thereof. Additionally or alternatively, the second array of magnets may be oriented in a semi-circular pattern when viewed along respective polar axes of the plurality of magnets thereof.
[0019] The at least one first magnet may be implemented using one or more of a permanent magnet, an electro-magnet, a superconductor magnet, and a semiconductor magnet. Additionally or alternatively, the at least one second magnet may be implemented using one or more of a permanent magnet, an electro-magnet, a superconductor magnet, and a semiconductor magnet.
[0020] The apparatus may further include a power source disposed within the helmet, where the at least one first magnet is implemented using at least one electro-magnet, and the power source within the helmet is coupled to, and provides operating power to, the at least one electro-magnet. Additionally or alternatively, the apparatus may further include a power source disposed within the shoulder pad assembly, where the at least one second magnet is implemented using at least one electro-magnet, and the power source within the shoulder pad assembly is coupled to, and provides operating power to, the at least one electro-magnet.
[0021] The apparatus may further include a cooling source disposed within the helmet, where the at least one first magnet is implemented using at least one a superconductor magnet, semiconductor magnet and/or electro-magnet, and the cooling source within the helmet is thermally coupled to, and cools, the at least one a superconductor magnet, semiconductor magnet and/or electro-magnet. The cooling mechanism may include at least one of a mechanical heat sink element and a Peltier cooling mechanism.
[0022] Additionally or alternatively, the apparatus may further include a cooling source disposed within the shoulder pad assembly, where the at least one second magnet is implemented using at least one a superconductor magnet, semiconductor magnet and/or electro-magnet, and the cooling source within the shoulder pad assembly is thermally coupled to, and cools, the at least one a superconductor magnet, semiconductor magnet and/or electro-magnet. Again, the cooling mechanism may include at least one of a mechanical heat sink element and a Peltier cooling mechanism.
[0023] In accordance with one or more further embodiments of the present invention, an apparatus may include: a helmet sized and shaped to receive and protect a user's head from injury, the helmet including at least one peripheral edge at least partially circumscribing an opening for receiving the user's head; a shoulder pad assembly sized and shaped to receive and protect the user's shoulders, the shoulder pad assembly including at least one peripheral edge at least partially circumscribing an opening through which the user's neck extends; a first housing coupled to the helmet and located at a lower, rear portion of the peripheral edge of the helmet, the first housing including a plurality of magnets forming a first array of magnets; and a second housing coupled to the shoulder pad assembly and located at a rear portion of the peripheral edge of the shoulder pad assembly, the second housing including a plurality of magnets forming a second array of magnets.
[0024] Each of the magnets of the first and second arrays of magnets include north and south poles. The first and second arrays of magnets may be oriented within the respective first and second housings, such that either the respective north poles of the respective pluralities of magnets, or the respective south poles of the respective pluralities of magnets, are directed toward one another to produce a magnetic opposing force, which produces resistance to movement of the first and second housings toward one another when the helmet and the shoulder pad assembly are worn by the user.
[0025] The first array of magnets may be oriented in a semi-circular pattern when viewed along respective polar axes of the plurality of magnets thereof. Additionally or alternatively, the second array of magnets may be oriented in a semi-circular pattern when viewed along respective polar axes of the plurality of magnets thereof.
[0026] The first array of magnets may include one or more of a permanent magnet, an electro-magnet, a superconductor magnet, and a semiconductor magnet; and/or the second array of magnets may include one or more of a permanent magnet, an electro-magnet, a superconductor magnet, and a semiconductor magnet.
[0027] A first power source may be disposed within the helmet, the first array of magnets including at least one electro-magnet, superconductor magnet, and/or semiconductor magnet, and the first power source being coupled to, and providing operating power to, the at least one electro-magnet, superconductor magnet, and/or semiconductor magnet; and/or a second power source may be disposed within the shoulder pad assembly, the second array of magnets including at least one electro-magnet, superconductor magnet, and/or semiconductor magnet, and the second power source being coupled to, and providing operating power to, the at least one electro-magnet, superconductor magnet, and/or semiconductor magnet.
[0028] A cooling source may be disposed within the helmet and thermally coupled to, and cooling, the at least one semiconductor magnet, a superconductor magnet, and/or electro-magnet of the first array of magnets; and/or a cooling source may be disposed within the shoulder pad assembly and thermally coupled to, and cooling, the at least one semiconductor magnet, a superconductor magnet, and/or electro-magnet of the second array of magnets.
[0029] Those skilled in the art will further appreciate the above-mentioned features and advantages of the invention together with other superior aspects thereof upon reading the detailed description which follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] For the purposes of illustration, there are forms shown in the drawings that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0031] FIG. 1 is a back perspective view of the improved helmet and shoulder pads with magnetic movement restrictor in accordance with one or more embodiments of the present invention;
[0032] FIG. 2 is a side view of the improved helmet and shoulder pads with magnetic movement restrictor;
[0033] FIG. 3 is a another back perspective view of the improved helmet and shoulder pads with magnetic movement restrictor;
[0034] FIG. 4 is a back perspective view of the improved helmet with magnetic movement restrictor; and
[0035] FIG. 5 is a back perspective view of the improved shoulder pads with magnetic movement restrictor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] In the description which follows, like elements are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale in the interest of clarity and conciseness.
[0037] As depicted in FIGS. 1-5 , the magnetic movement restrictor 10 is comprised of a helmet 12 and shoulder pads 14 . As shown, the helmet 12 and shoulder pads 14 are designed for football, however, the movement restrictor could as easily be incorporated for use in motor sports or aviation, or any other application where whiplash or axial compressive forces cause injury. Attached to the rear, lower, exterior portion of the helmet 12 is a magnetic housing 16 . The magnetic housing 16 can be retrofitted to any existing helmet 12 , or can be supplied with a new helmet. The housing 16 itself can be constructed of a plastic similar to that of the helmet 12 . Likewise, the shoulder pads 14 have a magnetic housing 18 attached to the rear, upper, exterior portion. The magnetic housing 18 can be retrofitted to any existing set of shoulder pads 14 , or can be supplied with a new set of shoulder pads. The housing 18 can be made of plastic similar to the shoulder pads 14 .
[0038] Within the housing 18 is an array of magnets 20 . In one or more configurations, each of these magnets 20 may be oriented in the same manner, with similar poles facing upward towards the helmet 12 . Within the helmet housing 16 is an array of magnets 22 . In one or more configurations, each of these magnets 22 may be oriented in the same manner, with similar poles facing downward towards the shoulder pads 14 .
[0039] The magnets 22 on the helmet 12 may each have similar poles, say North for sake of example, facing towards the magnets 20 on the shoulder pads 14 . Similarly, the magnets 20 on the shoulder pads 14 may each have the same pole, North in this case, facing the magnets 22 of the helmet 12 . The respective sets of magnets 20 , 22 , with like poles facing each other, create an opposing force which resists movement of the helmet 12 towards the shoulder pads 14 . Thus, the magnets 20 of the housing 16 and the magnets 22 of the housing 16 provide a cushioning effect for the user.
[0040] In alternative embodiments, there may be a single magnet 20 in the housing 16 and a single magnet in the housing 18 , each of which is sized and shaped to achieve the opposed configuration and cushioning effect.
[0041] The magnets 20 , 22 may be permanent magnets, electromagnets, and/or super-conductor magnets. In the case that the magnets 20 , 22 are electromagnets, the power sources 32 , 34 therefor may be located in the respective housings 18 , 16 . Likewise, in the case that the magnets 20 , 22 are super-conductors, the cooling sources 36 , 38 therefor may be located in the respective housings 18 , 16 .
[0042] The construction and use of the magnetic movement restrictor 10 , in conjunction with the helmet 12 and shoulder pad assembly 14 , is believed to be readily understandable to those of ordinary skill in the art from the foregoing description. The restrictor 10 can be easily included in the helmet 12 or shoulder pad assembly 14 at the time of manufacture or can be retrofitted to existing shoulder pad assemblies, if desired. The materials used in fabricating the support and movement restrictor 10 have been described in some detail, and the fabrication of the component parts of the restrictor are believed to be within the capability of those skilled in the art.
[0043] Other combinations of elements contemplated herein in accordance with various embodiments include:
[0044] A helmet support and movement restrictor for use in conjunction with a shoulder pad assembly comprising: a helmet with at least one magnet and a set of shoulder pads with at least one magnet.
[0045] A helmet support and movement restrictor as set forth above, where the magnet on the helmet creates an opposing force to the shoulder pads magnet.
[0046] A helmet support and movement restrictor as set forth above, where the magnets restrict rearward hypertension and whiplash movement of the user's head and/or neck.
[0047] A helmet support and movement restrictor as set forth above, where the magnets restrict axial compression of the wearer's neck.
[0048] A helmet support and movement restrictor set forth above, where the helmet magnet is a permanent magnet.
[0049] A helmet support and movement restrictor set forth above, where the helmet magnet is an electro-magnet.
[0050] A helmet support and movement restrictor set forth above, where the helmet magnet has an internal power source within the helmet.
[0051] A helmet support and movement restrictor set forth above, where the helmet magnet is a semiconductor magnet.
[0052] A helmet support and movement restrictor set forth above, where the helmet magnet has an internal cooling source within the helmet.
[0053] A helmet support and movement restrictor set forth above, where the shoulder pad magnet is a permanent magnet.
[0054] A helmet support and movement restrictor set forth above, where the shoulder pad magnet is an electro-magnet.
[0055] A helmet support and movement restrictor set forth above, where the shoulder pad magnet has an internal power source within the shoulder pads.
[0056] A helmet support and movement restrictor set forth above, where the shoulder pad magnet is a semiconductor magnet.
[0057] A helmet support and movement restrictor set forth above, where the shoulder pad magnet has an internal cooling source within the shoulder pads.
[0058] A helmet support and movement restrictor set forth above, where the helmet has more than one magnet.
[0059] A helmet support and movement restrictor set forth above, where at least one magnet on the helmet is a permanent magnet.
[0060] A helmet support and movement restrictor set forth above, where at least one magnet on the helmet is an electro-magnet.
[0061] A helmet support and movement restrictor set forth above, where the helmet magnet has an internal power source within the helmet.
[0062] A helmet support and movement restrictor set forth above, where at least one magnet on the helmet is a semiconductor magnet.
[0063] A helmet support and movement restrictor set forth above, where the helmet magnet has an internal cooling source within the helmet.
[0064] A helmet support and movement restrictor set forth above, where the shoulder pads have more than one magnet.
[0065] A helmet support and movement restrictor set forth above, where at least one magnet on the shoulder pads is a permanent magnet.
[0066] A helmet support and movement restrictor set forth above, where at least one magnet on the shoulder pads is an electro-magnet.
[0067] A helmet support and movement restrictor set forth above, where the shoulder pads magnet has an internal power source within the shoulder pads.
[0068] A helmet support and movement restrictor set forth above, where at least one magnet on the shoulder pads is a semiconductor magnet.
[0069] A helmet support and movement restrictor set forth above, where the shoulder pads magnet has an internal cooling source within the helmet.
[0070] The magnetic helmet support and magnetic movement restrictor of the embodiments of the present invention provides several advantages for use in conjunction with shoulder pads.
[0071] The configuration of the magnetic helmet support and magnetic movement restrictor avoids contact with the wearer during normal head movement, does not restrict turning or sideways head movement, does not attach to a helmet in such a way as to impose unwanted loads on other parts of the body when opposing hyperextension or whiplash movement, may be easily retrofitted to existing shoulder pad assemblies or easily attached to new shoulder pad assemblies during manufacture, and is itself relatively easy and economical to manufacture.
[0072] 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 as defined by the appended claims.
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A helmet and shoulder pad combination is provided with an improved helmet support and restrictor to minimize rearward hyperextension and whiplash-type head movement as well as axial compression.
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BACKGROUND OF THE INVENTION
[0001] (a) Field of the Invention
[0002] The present invention relates to a buffer bearing for a drawer slide, and more particularly, to one that is provided with a buffer section and a receiving channel at where the bearing is connected with a separate part to have the buffer section to be compressed in the receiving channel when subjecting to impact for providing better buffer results.
[0003] (b) Description of the Prior Art
[0004] Drawers attached to a piece of furniture usually will be incorporated with slides for smooth sliding and efforts saving. Impacts are generated whenever the slide extends to a given position or is pushed back to open or close a drawer. Bearing incorporated to a buffer installation in certain slide products was used to reduce impact energy and noise or vibration level in the prior art as taught in Taiwan Patent Publication No. 499905 and U.S. Pat. Nos. 6,015,199 and 7,213,892 B2.
[0005] As disclosed in U.S. Pat. No. 6,015,199, an under-mount drawer slide is characterized in having a buffer producing from an end of a bearing seat; the buffer indicates a coil type and is connected to the bearing seat for the coiled buffer to sustain impacts on the slide by absorbing impact force for noise and vibration reduction.
[0006] However, the coiled buffer in relation to the bearing seat indicates an exposed protrusion and is made an integral part to the bearing seat to make the coil form being vulnerable to get deformed in indefinite direction within a partitioned space inside the slide when subjecting to impact. Once the deformation becomes beyond its critical point and gets damaged, replacement of the buffer is prevented. Furthermore, the application of the prior art is very limited because that the bearing seat for being integrated with the buffer fails to be adapted to other slides of different specifications and functional requirements.
SUMMARY OF THE INVENTION
[0007] The primary purpose of the present invention is to provide a buffer bearing for a drawer slide to solve the problems of failing separate replacement and lacking in common use of the bearing seat incorporated with the buffer of the prior art.
[0008] According to a first aspect of the present invention, there is provided buffer bearing for a drawer slide, comprising a connecting rod having a first connecting end and a second connecting end at respective two ends thereof; a first bearing seat having a horizontal upper wall and two vertical side walls, a number of rolling media being provided on the horizontal upper wall and the vertical side walls, the first bearing seat connecting to the first connecting end of the connecting rod; a second bearing seat having a horizontal upper wall and two vertical side walls, a number of rolling media being provided on the horizontal upper wall and the vertical side walls, the second bearing seat connecting to the second connecting end of the connecting rod, and a buffer section connected to the connecting rod.
[0009] Preferably, the first bearing seat is formed with a first receiving channel in a width corresponding to that of the first connecting end of the connecting rod, and retainers are provided in the first receiving channel in relation and holding to slots provided on two sides of the first connecting end.
[0010] Preferably, the second bearing seat is formed with a second receiving channel in a width corresponding to that of the second connecting end of the connecting rod, and retainers are provided in the second receiving channel in relation and holding to slots provided on two sides of the second connecting end.
[0011] Preferably, the buffer section is disposed with at least a corrugated extension.
[0012] Preferably, the buffer section is connected to a terminal of the first connecting end of the connecting rod.
[0013] Preferably, the buffer section is connected to a terminal of the second connecting end of the connecting rod.
[0014] Preferably, the buffer section is connected to the center of the first connecting end of the connecting rod.
[0015] Preferably, the buffer section is connected to the center of the second connecting end of the connecting rod.
[0016] Preferably, the connecting rod includes at least a first rod and a second rod; two ends respectively from the first rod and the second rod that face each other are disposed with a first connecting end and a third receiving channel; and the third connecting end is connected with another buffer section.
[0017] Preferably, the second connecting end of the connecting rod is integrated with the second bearing seat, and the first connecting end of the connecting rod is connected with the buffer section.
[0018] According to a second aspect of the present invention, there is provided a buffer bearing for a drawer slide, comprising a connecting rod having a first connecting end and a second connecting end at respective two ends thereof, a first bearing seat having a horizontal upper wall and two vertical side walls, a number of rolling media being provided on the horizontal upper wall and the vertical side walls, the first bearing seat being formed with a first receiving channel for connection of the first connecting end of the connecting rod; a second bearing seat having a horizontal upper wall and two vertical side walls, a number of rolling media being provided on the horizontal upper wall and the vertical side walls, the second bearing seat being formed with a second receiving channel for connection of the second connecting end of the connecting rod, and at least a buffer section disposed in either the first receiving channel of the first bearing seat or the second receiving channel of the second bearing seat.
[0019] Preferably, the first connecting end and the second connecting end of the connecting rod are provided slots on respective sides thereof, and the first receiving channel and the second receiving channel are provided with retainers for engagement of the slots of the first connecting end and the second connecting end.
[0020] Preferably, the buffer section is disposed with at least a corrugated extension.
[0021] Preferably, the second connecting end of the connecting rod is integrated with the second bearing seat, and the first connecting end of the connecting rod is connected with the first receiving channel of the first bearing seat and engages with the buffer section.
[0022] By referring to the prior art, the present invention provides the following improvements of results and advantages:
[0023] a. The buffer bearing may be combined with separate parts to allow economic benefits of replacing an individual part, and parts can be interchanged to save dies development and products cost.
[0024] b. The buffer section is provided by incorporating to interior space of the receiving channel for the buffer section maintains stable deformation due to compression to put deformation extent under effective control for providing longer service life of the buffer section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an exploded view of a preferred embodiment of the present invention.
[0026] FIG. 2 is a perspective view showing an assembly of the preferred embodiment of the present invention.
[0027] FIG. 3 is a schematic view showing changes of a buffer section and a connecting rod of the preferred embodiment of the present invention.
[0028] FIG. 4 is a schematic view showing the preferred embodiment of the present invention mounted to a slide assembly.
[0029] FIG. 5 is a schematic view showing a status of buffer by compression executed by the buffer section of the preferred embodiment of the present invention.
[0030] FIG. 6 is schematic view of a construction of a connecting rod breaking into multiple sections of the preferred embodiment of the present invention.
[0031] FIG. 7 is a schematic view showing a construction of having one end of the connecting rod integrated with a bearing seat of the preferred embodiment of the present invention.
[0032] FIG. 8 is an exposed view of another preferred embodiment of the present invention.
[0033] FIG. 9 is a schematic view showing a construction of having one end of the connecting rod integrated with a bearing seat of another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to FIGS. 1 and 2 , a preferred embodiment of the present invention comprises a connecting rod ( 1 ), a first bearing seat ( 2 ), a second bearing seat ( 3 ), and a buffer section ( 4 ).
[0035] The connecting rod ( 1 ) has respectively disposed to its opposite ends a first connecting end ( 11 ) and a second connecting end ( 12 ). The first connecting end ( 11 ) contains a buffer section ( 4 ). The second connecting end ( 12 ) also contains a buffer section ( 4 ). Each buffer section ( 4 ) indicates a corrugated extension. Both the first connecting end ( 11 ) and the second connecting end ( 12 ) are disposed with slots ( 13 ) at both sides thereof, respectively. As illustrated in FIG. 2 , the buffer section ( 4 ) is disposed at a terminal of each of the first connecting end ( 11 ) and the second connecting end ( 12 ). As illustrated in FIG. 3 , a buffer section ( 4 A) of a connecting rod ( 1 A) is disposed at the center of each of a first connecting end ( 11 A) and a second connecting end ( 12 A).
[0036] The first bearing seat ( 2 ) has a horizontal upper wall ( 21 ) and two vertical side walls ( 22 ). A number of rolling media ( 23 ) are provided on the horizontal upper wall ( 21 ) and the vertical side walls ( 22 ), respectively. Each of the rolling media ( 23 ) is a roller bearing. The first bearing seat ( 2 ) is formed with a first receiving channel ( 24 ) in a width corresponding to that of the first connecting end ( 11 ) of the connecting rod ( 1 ) to receive the first connecting end ( 11 ). Both side walls in the first receiving channel ( 24 ) are disposed with retainers ( 25 ) to hold against the corresponding slots ( 13 ) provided on the first connecting end ( 11 ) to prevent the first connecting end ( 11 ) and the buffer section ( 4 ) disengaging from the first receiving channel ( 24 ).
[0037] The second bearing seat ( 3 ) has a horizontal upper wall ( 31 ) and two vertical side walls ( 32 ). A number of rolling media ( 33 ) are disposed on the horizontal upper wall ( 31 ) and the vertical side walls ( 32 ), respectively. Each of the rolling media ( 33 ) is a roller bearing. The second bearing seat ( 3 ) is formed with a second receiving channel ( 34 ) in a width corresponding to that of the first connecting end ( 12 ) of the connecting rod ( 1 ) to receive the second connecting end ( 12 ). Both side walls in the first receiving channel ( 24 ) are disposed with retainers ( 35 ) to hold against the corresponding slots ( 13 ) provided on the second connecting end ( 12 ) to prevent the second connecting end ( 12 ) and the buffer section ( 4 ) disengaging from the second receiving channel ( 34 ).
[0038] When the preferred embodiment of the present invention is adapted to a slide assembly as illustrated in FIG. 4 , both the first bearing seat ( 1 ) and the second bearing seat ( 2 ) respectively connected to the first connecting end ( 11 ) and the second connecting end ( 12 ) of the connecting rod ( 1 ) saddle onto a lower track (A) before being overlapped with an upper track (B). Upon pulling out or pushing back the upper track (B) to subject both the first bearing seat ( 2 ) and the second bearing seat ( 3 ) to impact as illustrated in FIG. 5 , both the first bearing seat ( 2 ) and the second bearing seat ( 3 ) slide and press against the connecting rod ( 1 ); in turn, the connecting rod ( 1 ) has the buffer sections ( 4 ) respectively extending from the first connecting end ( 11 ) and the second connecting end ( 12 ) to hold against the inner walls of the first receiving channel ( 24 ) and the second receiving channel ( 34 ). The corrugated extensions of the buffer sections ( 4 ) of the connecting rod ( 1 ) create compression inside the first receiving channel ( 24 ) and the second receiving channel ( 34 ) to provide buffer results.
[0039] Now referring to FIG. 6 , a connecting rod ( 1 B) may be connected by sections and includes at least a first rod ( 14 B) and a second rod ( 15 B). A third connecting end ( 16 B) and a third receiving channel ( 17 B) are disposed at where the first rod ( 15 B) and the second rod ( 15 B) are abutted to each other. The third connecting end ( 16 B) contains a buffer section ( 4 B). The connecting rod ( 1 B) is respectively provided at its both outer ends a first connecting end ( 11 B) and a second connecting end ( 12 B). Each of both the first connecting end ( 11 B) and the second connecting end ( 12 B) contains a buffer section ( 4 B).
[0040] As illustrated in FIG. 7 , a second connecting end ( 12 C) of a connecting rod ( 1 C) is directly connected to and integrated with a second bearing seat ( 3 C). A buffer section ( 4 C) is disposed on a first connecting end ( 11 C) at one end of the connecting rod ( 1 C). A first receiving channel ( 24 C) of a first bearing seat ( 2 C) is connected to the first connecting end ( 11 C) provided with the buffer section ( 4 C).
[0041] In another preferred embodiment of the present invention as illustrated in FIG. 8 , both ends of a connecting rod ( 1 D) are disposed with a first connecting end ( 11 D) and a second connecting end ( 12 D), respectively. Both sides of each of the first connecting end ( 11 D) and the second connecting end ( 12 D) are provided with slots ( 13 D). A first receiving channel ( 24 D) is disposed on a first bearing seat ( 2 D) to receive the first connecting end ( 11 D). The first receiving channel ( 24 D) contains a buffer section ( 4 D) to hold against a terminal of the first connecting end ( 11 D) of the connecting rod ( 1 D). Both side walls in the first receiving channel ( 24 ) are disposed with retainers ( 25 D) to hold against the slots ( 13 D) of the first connecting end ( 11 D) to prevent the first connecting end ( 11 D) disengaging from the first receiving channel ( 24 D). A second receiving channel ( 34 D) is disposed on a second bearing seat ( 3 D) to receive the second connecting end ( 12 D) of the connecting rod ( 1 D). A buffer section ( 4 D) is also disposed in the second receiving channel ( 34 D) to hold against a terminal of the second connecting rod ( 12 D) of the connecting rod ( 1 D). Both side walls in the second receiving channel ( 34 D) are disposed with retainers ( 35 D) to hold against the slots ( 13 D) of the second connecting end ( 12 D) to prevent the second connecting end ( 12 D) disengaging from the second receiving channel ( 34 D).
[0042] As illustrated in FIG. 9 , a second connecting end ( 12 E) of a connecting rod ( 1 E) is directly connected and integrated with a second bearing seat ( 3 E). A first receiving channel ( 24 E) of a first bearing seat ( 2 E) is disposed with a buffer section ( 4 E). A first connecting end ( 11 E) at one end of the connecting rod ( 1 E) is connected to the first receiving channel ( 24 E) provided with the buffer section ( 4 E).
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A buffer bearing for a drawer slide includes a connecting rod, a first bearing seat, and a second bearing seat. Both ends of the connecting rod are connected to the first and the second bearing seats, respectively. A buffer section and a receiving channel are provided at where the connecting rod is connected to the first bearing seat and where the connecting rod is connected to the second bearing seat for the buffer sections to be compressed within the receiving channels when subject to impact.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of U.S. provisional patent application Ser. No. 61/437,749 filed Jan. 31, 2011 which application is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH OR DEVELOPMENT
This invention was made with government support under Grant Nos. CA134128, CA128906 and EB004015 awarded by the National Institutes of Health. The Government has certain rights in the invention.
FIELD OF THE INVENTION
The invention relates to x-ray-based imaging systems and methods in general and particularly to an imaging system and method that provides x-ray images.
BACKGROUND OF THE INVENTION
Digital radiography provides a two-dimensional (2-D) image of a three-dimensional (3-D) object resulting in superposition of structures. Stereoscopic imaging is a technique wherein at least two 2-D x-ray projection images, referred to as an image pair, separated by an angle not exceeding 20-degrees (typically, 3 to 10 degrees) are acquired and displayed on a stereo-capable display. Such display may include two monitors each displaying one of the projection images, and the displayed projection images are viewed through cross-polarized mirrors and lenses, resulting in one eye visualizing one image and the other eye the other image. Alternatively, the images can be visualized using “3-D displays” such as those used in consumer electronics. In typical implementation of stereoscopic imaging, the image pair is acquired by physical movement of a single x-ray tube. Digital tomosynthesis is a technique wherein a plurality of 2-D x-ray projections are acquired over a limited angular range not exceeding 180-degrees (typically, 15 to 90 degrees) and mathematically reconstructed to provide a quasi-tomographic or 3-D image of object. This technique has the potential to improve detection of an abnormality in body anatomy and is being actively investigated for breast, chest and abdominal imaging. FDA-approved clinical systems for chest imaging and for breast imaging have been developed by various manufacturers.
In typical implementation of digital tomosynthesis, (n+1) projections are acquired over an angular range of −θ to +θ spanning 2θ degrees. Here n is a positive integer. Typically, the peak tube voltage (given in kilovolts peak, or kVp) applied across the anode-cathode of the x-ray tube, and the anode target and x-ray beam filter, referred to target/filter are maintained the same during acquisition of the (n+1) projections. The kVp and target/filter define the x-ray spectral shape, and in combination with the tube current (in millamps), or mAs where mAs is the product of tube current in mA and the x-ray exposure duration in seconds) define the x-ray fluence (photons per unit area). In early studies (see Niklason, L. T., B. T. Christian, L. E. Niklason, D. B. Kopans, D. E. Castleberry, B. H. OpsahlOng, C. E. Landberg, P. J. Slanetz, A. A. Giardino, R. Moore, D. Albagli, M. C. DeJule, P. F. Fitzgerald, D. F. Fobare, B. W. Giambattista, R. F. Kwasnick, J. Q. Liu, S. J. Lubowski, G. E. Possin, J. F. Richotte, C. Y. Wei, and R. F. Wirth, Digital Tomosynthesis in breast imaging . Radiology, 1997. 205(2): p. 399-406; Suryanarayanan, S., A. Karellas, S. Vedantham, S. P. Baker, S. J. Glick, C. J. D'Orsi, and R. L. Webber, Evaluation of linear and nonlinear tomosynthetic reconstruction methods in digital mammography . Acad Radiol, 2001. 8(3): p. 219-24; and Suryanarayanan, S., A. Karellas, S. Vedantham, S. J. Glick, C. J. D'Orsi, S. P. Baker, and R. L. Webber, Comparison of tomosynthesis methods used with digital mammography . Acad Radiol, 2000. 7(12): p. 1085-97), tube current was also maintained the same during acquisition of the (n+1) projections.
In current practice, the multiple views required for tomosynthesis require the physical rotation of the x-ray tube for each tomographic view. Although this is technically attainable, the physical movement of the tube is the source of many problems in tomosynthesis. A moving x-ray tube prolongs the exposure time and the duration of physical compression of the breast that in turn increases patient discomfort. Moreover, the resulting longer image acquisition time is more likely to contribute to blurring of the images due to patient motion and physical movement of the x-ray tube.
Systems using multiple stationary x-ray sources have been described by others for use in tomosynthesis, particularly for breast imaging (Kautzer et al. US 2005/0226371 A1 and U.S. Pat. No. 7,330,529 B2, Ludwig et al. US 2010/0091940 A1, Zhou et al. U.S. Pat. No. 7,751,528). However, such systems lack a central high power x-ray tube or other type of high-power x-ray source. A tomosynthesis system with a series of stationary sources will have no capability of performing conventional digital mammography because this requires a relatively high power x-ray source to provide sufficient x-ray fluence rate (defined as the number of x-ray photons per unit area per unit time, or x-ray fluence per unit time) that meet mammographic requirements for a reasonably short x-ray exposure, typically between 0.3 to 2.0 second duration. The fixed multi-spot x-ray sources are significantly underpowered and currently they are not capable of delivering the high x-ray fluence needed for mammography in an acceptable time frame to minimize patient motion. Therefore, such systems will be limited to tomosynthesis use only and not mammography. However, a mammographic or radiographic unit that can only operate in the tomosynthesis mode is too limited and it will not be desirable in most medical practices, because most breast imaging centers would prefer a system that can perform both tests. The same reasoning applies to digital radiography and tomosynthesis of other parts of the body such as chest, abdominal and pelvic imaging.
Some mammographic and radiographic imaging systems currently manufactured can perform conventional digital mammography and tomosynthesis on demand. In the conventional approach, tomosynthesis can be performed by a mechanical scan of the rotating anode x-ray tube over an arc of about +/−30 degrees from the center and acquiring typically from 15 to 25 images across this scan. The detector may remain stationary or it can rotate and/or move laterally to track the x-ray beam. Each of the 15 to 25 images require a combination of rapid activation of the x-ray tube (termed as “fire”) followed by a mechanical movement to the next position for the next fire or x-ray source activation. This rapid firing and mechanical repositioning creates many problems that lead to a less than optimal tomosynthesis image acquisition. During each firing there is a rise and fall “pulse” of the x-ray tube voltage. The tube current and x-ray output can be hard to control without elaborate and expensive electronic controls. Any irregularities in this pulse can contribute to an increased dose to the patient particularly due to the slow rise and drop of the waveform. Moreover, the x-ray filament is susceptible to the mechanical vibrations of the movement of the tube and this can have a negative effect on the spatial resolution of images. A mechanical “stop-fire-and-go” approach is very problematic because of the mechanical instabilities due to acceleration and deceleration of the mechanical assembly of the x-ray source. Continuous mechanical movement is generally preferred but it also prone to vibrations that can affect the image quality. In addition, during each firing that is of finite duration, the x-ray tube is in continuous motion resulting in blurring that degrades image quality. It typically takes between four to ten seconds for a complete acquisition and this increases the chances for a slight movement of the breast or other part of the body that will degrade the spatial resolution and diagnostic quality of the images. This motion problem can be minimized by applying additional compression on the breast using the pneumatic compression mechanism and plate but this is highly undesirable because of increased pain or discomfort. In chest and abdominal radiography this problem is even more serious because shorter exposures are required, typically in the order of milliseconds in chest imaging. A published international patent application by Ren et al. (WO 2010/060007 A1) discusses some of the issues of mechanical scanning approaches.
Other prior art known to the inventors includes the following patents and published applications.
U.S. Pat. No. 6,649,914 issued to Moorman et al. on Nov. 18, 2003 is said to describe an x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array.
U.S. Pat. No. 7,099,435 issued to Heumann on Aug. 29, 2006 is said to describe a tomographic reconstruction method and system incorporating Bayesian estimation techniques to inspect and classify regions of imaged objects, especially objects of the type typically found in linear, areal, or 3-dimensional arrays.
U.S. Pat. No. 7,545,907 issued to Stewart on Jun. 9, 2009 is said to describe a method of obtaining projection data of an object from a plurality of view angles with respect to the object is provided. The method comprises acts of providing radiation, at each of the plurality of view angles, to an exposure area in which the object is positioned, controlling a radiation energy of the radiation provided at each of the plurality of view angles such that the respective radiation energy is different for at least two of the plurality of view angles, and detecting at least some of the radiation passing through the exposure area at each of the plurality of view angles to obtain the projection data.
U.S. Pat. No. 7,551,716 issued to Ruhrnschopf on Jun. 23, 2009 is said to describe scatter correction methods for breast imaging and is relevant to the “scatter compensation in tomosynthesis” aspect of our disclosure. The approach described by Ruhrnschopf uses a pre-computed library of scatter spread functions using Monte Carlo simulations, which is a standard computational tool for scatter estimation. We have published previously Monte Carlo simulations of scatter as a function of tomosynthesis projection angle. See Sechopoulos, I., S. Suryanarayanan, S. Vedantham, C. J. D'Orsi, and A. Karellas, Scatter radiation in digital tomosynthesis of the breast . Med Phys, 2007. 34(2): p. 564-76.
U.S. Patent Application Publication No. 20090268865 A1 (Ren et al.) published on Oct. 29, 2009. This patent application is said to describe a method and an apparatus for estimating a geometric thickness of a breast in mammography/tomosynthesis or in other x-ray procedures, by imaging markers that are in the path of x-rays passing through the imaged object.
U.S. Pat. No. 7,616,801 issued to Gkanatsios et al. on Nov. 10, 2009 is said to describe a method and system for acquiring, processing, storing, and displaying x-ray mammograms Mp and tomosynthesis images Tr representative of breast slices, and x-ray tomosynthesis projection images Tp taken at different angles to a breast, where the Tr images are reconstructed from Tp images.
U.S. Patent Application Publication No. 20100063410 A1 (Avila), published Mar. 11, 2010, describes obtaining a lung cancer risk index based on combining information from multiple sources such as spirometry, chest CT or other x-ray examination including x-ray tomosynthesis with airflow lung function measurements.
U.S. Pat. No. 7,680,240 issued to Manjeshwar on Mar. 16, 2010 is said to describe methods for performing image reconstruction that include deriving background projection data for an area outside a targeted field of view of a tomographic image, and reconstructing the tomographic image of the targeted field of view, wherein the background projection data is used in the reconstruction.
U.S. Pat. No. 7,697,661 issued to Souchay et al. on Apr. 13, 2010 is said to describe a method wherein the irradiation dose to the breast is distributed in a manner based on the orientation of the x-ray beam followed by filtering of the projections to ensure optimum propagation of the signal-to-noise ratio.
U.S. Pat. No. 7,702,142 issued to Ren on Apr. 20, 2010 is said to describe a method and a system for using tomosynthesis projection images of a patient's breast to reconstruct slice tomosynthesis images such that anatomical structures that appear superimposed in a mammogram are at conforming locations in the reconstructed images.
U.S. Pat. No. 7,751,528 issued to Zhou on Jul. 6, 2010 is said to describe using a stationary array of x-ray sources to facilitate tomosynthesis.
Other references known to the inventors include the following non-patent literature: Nishikawa, R. M., I. Reiser, P. Seifi, and C. J. Vyborny, A new approach to digital breast tomosynthesis for breast cancer screening, in Medical Imaging 2007: Physics of Medical Imaging , J. Hsieh and M. J. Flynn, Editors. 2007, SPIE. p. 65103C; and Sechopoulos, I., S. Suryanarayanan, S. Vedantham, C. D'Orsi, and A. Karellas, Computation of the glandular radiation dose in digital tomosynthesis of the breast . Med Phys, 2007. 34(1): p. 221-32.
A number of problems in attempting to implement a method and system that provides both radiographic and tomographic images have been observed.
There is a need for methods and systems that provide radiographic, stereoscopic and tomographic images.
SUMMARY OF THE INVENTION
According to one aspect, the invention features an x-ray apparatus for making an image. The x-ray apparatus comprises an object holder configured to position an object of interest to allow the making of an image of the object; an x-ray source configured to provide a first x-ray beam having a high x-ray fluence rate to illuminate the object of interest along a first axis; at least one peripheral satellite x-ray source configured to provide at least one secondary x-ray beam having lower x-ray fluence rate than the fluence rate of the first x-ray beam, the at least one secondary x-ray beam configured to illuminate the object of interest along a respective axis that is angularly displaced from the first axis; a detector configured to detect x-ray radiation that has passed through the object of interest from the x-ray source and from the at least one peripheral satellite x-ray source, the detector having an output port configured to provide non-volatile signals representative of the detected x-ray radiation that has passed through the object of interest; a controller configured to command the operation of the x-ray source, configured to command the operation of each of the at least one peripheral satellite x-ray source, and configured to command the operation of the detector to generate the non-volatile signals representative of the detected x-ray radiation that has passed through the object of interest; and a computation unit configured to receive the non-volatile signals representative of the detected x-ray radiation from the detector and configured to manipulate the non-volatile signals representative of the detected x-ray radiation to provide at least one image of the object of interest, the computation unit configured to perform at least one action selected from the group of actions consisting of recording the image of the object of interest, displaying to a user the image of the object of interest, and transmitting the image to a data handling system.
In one embodiment, the object of interest is a body part of a living being.
In another embodiment, the body part of a living being is a human breast.
In yet another embodiment, the x-ray source and at least one peripheral satellite x-ray source are configured to be rotated as a combined unit with reference to the object of interest.
In still another embodiment, the x-ray source and at least one peripheral satellite x-ray source are configured to be positioned independently of one another with reference to the object of interest.
In a further embodiment, at least one peripheral satellite x-ray source is configured to be operated individually.
In yet a further embodiment, the detector is configured to be stationary, or is configured to rotate or move laterally to track an x-ray beam.
In an additional embodiment, the controller is configured to control a parameter selected from the group of parameters consisting of an x-ray beam energy, an x-ray beam fluence rate and an x-ray beam duration in response to an orientation of the x-ray beam.
In one more embodiment, the apparatus further comprises an anti-scatter grid located in an x-ray beam path.
In still a further embodiment, the apparatus further comprises a computational unit configured to apply an x-ray scatter correction method.
In one embodiment, at least one image of the object of interest is an image selected from the group of images consisting of a radiographic image, a stereoscopic image, and a tomographic image.
In another embodiment, the x-ray source configured to provide a first x-ray beam having a high x-ray fluence rate is a high power source.
In a further embodiment, the high power source is selected from the group of sources consisting of a rotating anode source, a high fluence field emission source, and a synchrotron.
According to another aspect, the invention relates to a method of making a plurality of images. The method comprises the steps of providing an object of interest for the purpose of making an image of the object; illuminating the object of interest with a first x-ray beam having a high x-ray fluence rate, the first x-ray beam propagating along a first axis; illuminating the object of interest with at least one secondary x-ray beam having lower x-ray fluence rate than the fluence rate of the first x-ray beam, the at least one secondary x-ray beam propagating along a respective axis that is angularly displaced from the first axis; detecting the first x-ray beam and the at least one secondary x-ray beam after they have each passed through the object of interest; generating non-volatile signals representative of the detected x-ray radiation that has passed through the object of interest; manipulating the non-volatile signals representative of the detected x-ray radiation to provide a plurality of images of the object of interest, the plurality of images comprising a stereoscopic image and at least one image selected from the group consisting of a radiographic image and a tomographic image; and performing at least one action of recording the images, transmitting the images to a data handling system, and displaying the images to a user.
In one embodiment, the step of illuminating the object of interest with a first x-ray beam, the step of illuminating the object of interest with at least one secondary x-ray beam, the step of detecting the first x-ray beam and the at least one secondary x-ray beam, and the step of generating non-volatile signals representative of the detected x-ray radiation are performed in response to commands from a controller.
In another embodiment, the step of illuminating the object of interest with a first x-ray beam and the step of illuminating the object of interest with at least one secondary x-ray beam are performed in any order.
In yet another embodiment, the step of illuminating the object of interest with at least one secondary x-ray beam includes illuminating the object of interest with a first of the at least one secondary x-ray beams in a first time interval and illuminating the object of interest with a second of the at least one secondary x-ray beams in a second time interval different from the first time interval.
In still another embodiment, the source of a first of the at least one secondary x-ray beams provides x-ray illumination while a source of a second of the at least one secondary x-ray beams is moving.
In a further embodiment, at least one of the steps of illuminating the object of interest comprises illuminating the object of interest with an x-ray beam having at least one parameter selected from the group of parameters consisting of x-ray beam energy, x-ray fluence rate and x-ray beam duration, the at least one parameter having a value that is dependent on an orientation of the x-ray beam.
In yet a further embodiment, at least one of the steps of illuminating the object of interest with at least one secondary x-ray beam is used to provide one or more of the stereoscopic image, the radiographic image and the tomographic image.
In an additional embodiment, the step of illuminating the object of interest with at least one secondary x-ray beam is used for stereotactic localization to obtain samples of the object of interest.
In one more embodiment, at least one of the steps of illuminating the object of interest comprises the steps of illuminating the object of interest with an anti-scatter grid in an x-ray beam path; illuminating the object of interest without an anti-scatter grid in the x-ray beam path, and; applying an x-ray scatter correction method comprising the steps of: estimating an x-ray scatter present in an image recorded at a first beam orientation; determining an x-ray scatter present in an image recorded at a second beam orientation different from the first beam orientation by using the estimated x-ray scatter estimated at the first beam orientation; and applying the determined x-ray scatter as a correction for x-ray scatter in an image recorded at the second beam orientation.
In still a further embodiment, the step of determining an x-ray scatter present in an image recorded at a second beam orientation is performed using Monte Carlo simulations.
In yet another embodiment, the step of determining an x-ray scatter present in an image recorded at a second beam orientation is performed using a library of data that accounts for the range of dimensions and properties of the object.
In still another embodiment, the step of applying the determined x-ray scatter as a correction is performed using at least one mathematical procedure selected from the group of mathematical procedures consisting of analytical mathematical operations, iterative mathematical operations, convolution techniques and de-convolution techniques.
The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views.
FIG. 1 is a schematic diagram that shows a system according to principles of the invention that includes a central x-ray source and satellite x-ray source assemblies.
FIG. 2 is a schematic diagram that shows a variation of the described approach with the satellite x-ray source assemblies (right and left) spread in an arc away from the central x-ray source, according to principles of the invention.
FIG. 3 is a schematic diagram that shows a variation of the described approach that is used when only a conventional mammogram is required.
FIG. 4 is another view of the relative positions of a patient, a portion of a patient's body that is being examined, and the position of the apparatus.
FIG. 5 is a schematic diagram that illustrates an embodiment in which the individual sources in the satellite x-ray sources are operated in sequence.
FIG. 6 is a schematic diagram that illustrates an embodiment in which the satellite x-ray sources comprise a plurality of discrete individual sources.
FIG. 7 is a schematic diagram that illustrates the components of an apparatus according to principles of the invention and the interactions among the components.
DETAILED DESCRIPTION
Combined Digital Mammography with High Speed Tomosynthesis
We describe a method for tomosynthesis imaging that uses a number of x-ray sources positioned on each side (or only on one side if desired) of the conventional central x-ray tube. This preferred embodiment enables fast tomographic image acquisition for tomosynthesis and for stereoscopic x-ray imaging. Image acquisition parameters (kVp, target/filter, mAs), either individually or in combination, can be varied with projection angle during acquisition of the (n+1) projections. We refer to such variation of operating parameters as angle adaptive beam modulation (AABM).
In order to overcome the limitations of prior art systems, it is desirable and advantageous to have a series of spatially fixed x-ray sources in an arc path that can activate sequentially or in any desired order to cover the desired angle of exposure in the shortest possible time.
We describe a system that is expected to be fully capable of operating as a state-of-the art mammography or radiography system and it also is expected to be capable of operating as a high speed tomosynthesis system by using a combination of a standard high power source and a plurality of peripheral “satellite” x-ray sources. We describe using a combined stationary x-ray source array and a conventional x-ray tube. The x-ray tube can be positioned at the center of the x-ray source array. This allows the use of high x-ray fluence rate projection acquisition using the standard x-ray tube and lower x-ray fluence rate projection acquisitions using the stationary x-ray source array. The combined x-ray tube and stationary x-ray source array can be rotated with reference to an object to be examined in order to facilitate finer angular sampling of the object. Alternatively, each source array can be rotated independently. It is possible in principle to use two or more lower x-ray fluence rate projection acquisitions using the stationary x-ray source array without the high x-ray fluence rate projection to generate some of the images discussed herein below.
In various embodiments, the high power source can be a conventional rotating anode source, or a non-conventional higher power x-ray source such as a high fluence field emission source or a synchrotron for the first axis projection rather than the stationary x-ray source. While the first axis can be a central axis (e.g., at zero-degrees in reference to the central ray axis), it is not required that it be a central axis; that is the first axis can be off-center in some embodiments. The preferred embodiments described use one or more banks of stationary sources interposed with a rotating anode x-ray source or a number of lower powered sources interposed with a rotating anode x-ray source. The use of a rotating anode x-ray source is significant so as to provide sufficient x-ray output for digital mammography. Rotating anode x-ray tubes designed for mammography can provide upwards of 5 KW power (Tube voltage: 50 kV, Tube current: 100 mA), whereas stationary sources can only provide tube currents of the order of 3 to 7 mA, as described in a recent article from Zhou's research group (see Calderon-Colon, X., H. Geng, B. Gao, L. An, G. Cao, and O. Zhou, A carbon nanotube field emission cathode with high current density and long - term stability . Nanotechnology, 2009. 20(32): p. 325707).
We describe a dual-use mammographic and tomosynthesis system that is also capable of stereoscopic imaging and stereotactic localization and employs a conventional central x-ray source and detector with an additional set of x-ray sources (satellite sources, 4 ) on each side of a conventional x-ray source ( 1 ) as shown in FIG. 1 and FIG. 2 . As is well-known in the x-ray imaging and tomographic imaging arts, once data is acquired using a detector, the data is manipulated in a general purpose programmable computer operating with instructions recorded in non-volatile memory accessible by and readable by the general purpose programmable computer. The images that are extracted from the acquired data can be recorded, can be transmitted to another computational system, and/or can be displayed to a user of the imaging system.
FIG. 1 is a schematic diagram that shows several important features of an embodiment of the invention. Illustrated in FIG. 1 are the elements of a digital mammography or tomosynthesis unit with a conventional x-ray tube ( 1 ), which can be a rotating anode x-ray tube or a stationary anode x-ray tube. The x-ray tube has at least one small high heat load focal spot ( 2 ). An x-ray beam collimator ( 3 ) and an x-ray beam filter ( 9 ) are provided to control the high power x-ray beam emanating from the x-ray tube ( 1 ). Also present is an x-ray source assembly ( 4 ) having a plurality of x-ray sources ( 5 ). The x-ray source assembly ( 4 ) also termed “satellite sources”) is constructed of multiple segments which are movable, with a center of rotation ( 12 ) about which each of the x-ray sources ( 5 ) can be rotated. In one embodiment, the x-ray sources ( 5 ) are x-ray sources constructed using field emission x-ray sources. In other embodiments, other types of x-ray sources can be used. Multiple x-ray beam collimators ( 8 ) are provided to collimate the x-ray beam emanating from each of the x-ray sources ( 5 ). The breast ( 6 ) of a patient is illustrated under compression by a breast compression plate ( 11 ). A digital imaging detector ( 7 ) is provided to record the intensity of the x-ray beams ( 10 ) that are used to generate mammographic and tomographic images. The digital imaging detector ( 7 ) can be oriented normal to the axis of the rotating anode x-ray tube ( 1 ) or it can be tilted or shifted to provide angulated views. The digital imaging detector ( 7 ) can be made of amorphous selenium with a thin film transistor (TFT) or optical readout, or an amorphous silicon detector with a scintillator or a photon counting detector. The x-ray sources operate in a range of kVp from about 20 to 150 so that the range that is used for mammography (20 to 50 kVp) and for adult and pediatric radiography (40 to 150 kVp) can be covered.
This approach obviates the mechanical scanning of the x-ray tube to perform tomosynthesis. Conventional mammography in the craniocaudal, mediolateral and other mammographic views can be performed by rotating the tube and detector c-arm assembly as in the conventional approach. However, the tomosynthesis acquisition can be acquired by firing the satellite x-ray sources in a predetermined sequence. The satellite x-ray sources are typically of the field emission type (using carbon nanotubes or other components) and they are integrated in groups of two or more as shown in FIG. 1 . One advantage of this design is the ability to fire a very rapid sequence of tomosynthesis projections without mechanical movement of the main x-ray source (tube 1 ). This enables a tomographic acquisition in a very short time, typically in the order of approximately one second, that represents at least a tenfold improvement over existing techniques. Moreover, the tomographic acquisition can be performed in the same sequence as the conventional view. For example, the conventional mammographic view can be acquired at a typical exposure time from about one-half second to three seconds followed by or preceded immediately by a tomographic acquisition without repositioning the breast. For chest radiography, the exposure time will be in the millisecond range, typically between 1 millisecond to 1 second. This approach enables for the visualization of conventional and tomographic images that have been acquired in the same position and they can be digitally fused for better correlation between conventional mammographic image and tomographic image acquisition. The use of multiple x-ray sources is expected to require test procedures and calibrations to minimize variation in x-ray beam quality and quantity.
FIG. 2 is a schematic diagram that shows a variation of the described approach with the satellite x-ray source assemblies ( 4 right and 4 left) spread in an arc away from the central x-ray source 1 . In this embodiment a tomosynthesis acquisition can be made at different angles from the center. Moreover, each satellite source assembly can be positioned in a way that can be rotated independently or in synchrony with the other assembly.
FIG. 3 is a schematic diagram that shows a variation of the described approach that is used when only a conventional mammogram is required. In FIG. 3 , it is shown how the satellite x-ray source assemblies ( 4 ) can be translated away from the patient (to locations 13 and/or 14 as shown) or can be tilted away from the patient, which motion is not shown. In some embodiments, the satellite x-ray source assemblies ( 4 ) can be moved individually. In some embodiments, the satellite x-ray source assemblies ( 4 ) can be moved as a unit, in which case a mechanical link ( 15 ) between the two satellite x-ray source segments can be provided. In some embodiments, mechanical detents are provided to assure that the satellite x-ray sources ( 4 ) are returned to carefully controlled positions for use in conjunction with the x-ray tube ( 1 ) as previously described. In some embodiments, locating devices such as optical, electrical or magnetic encoders are provided to assure that the satellite x-ray sources ( 4 ) are returned to carefully controlled positions for use in conjunction with the x-ray tube ( 1 ) as previously described. The ability to temporarily displace the satellite x-ray sources ( 4 ) can be helpful in improving patient positioning. Outlines of the location of a patient' head ( 16 ) and body ( 17 ) are indicated in FIG. 3 .
FIG. 4 is another view of the relative positions of a patient, a portion of a patient's body that is being examined, and the position of the apparatus. FIG. 4 shows the satellite x-ray sources ( 4 ) in position for providing a tomography image, and in positions (locations 13 and/or 14 as shown) where the satellite x-ray sources are not expected to be used in making a tomographic image. In FIG. 4 , the outline of the patient represents a patient closer to the viewer than the apparatus is to the viewer (e.g., one is looking through the patient), and the patient has her back to the viewer.
The firing of each x-ray tube can be activated in a number of ways. For example, in one mode of operation, the left source assembly can fire each source sequentially while both assemblies are positioned adjacent to the central x-ray source as shown in FIG. 1 . Subsequently, the right assembly fires sequentially while the left assembly moves a predetermined distance counterclockwise (away from the central source). After firing of the selected sources is completed in the right assembly, firing of the sources starts on the left source assembly from its new position farther away from the central x-ray source (tube 1 ). This approach allows the combination of an electronic and mechanical positioning of the focal spot thereby allowing for speed and the ability to acquire projections from various points beyond what is dictated by the number of available satellite x-ray sources.
FIG. 1 and FIG. 2 show a symmetric positioning of the satellite x-ray sources on each side of the main x-ray source ( 1 ). In other modes of operation, an asymmetric arrangement may also be desirable. An arrangement using a central x-ray source ( 1 ) in conjunction with just two satellite sources ( 5 ) is also desirable particularly for stereo-mammography.
FIG. 5 is a schematic diagram that illustrates an embodiment in which the individual sources in the satellite x-ray sources ( 4 ) are operated in sequence. In FIG. 5 ten individual sources in the satellite x-ray sources ( 4 ) are represented by filled dark circles and are labeled 31 through 40 . In the position illustrated, sources 31 through 35 may be fired in a desired sequence, such as in succession or in some other order. While sources 36 to 40 are being fired in the desired sequence, the segment of the satellite x-ray source containing sources 31 - 35 moves in a counterclockwise motion of a pre-defined number of degrees (or pre-defined in units represented by another frame of reference). After the motion is completed, the sources 31 - 35 are located at the positions illustrated by open circles. Sources 31 - 35 can then be fired again in a desired sequence, while the segment of the satellite x-ray source containing sources 36 - 40 moves in a clockwise motion of a pre-defined number of degrees (or pre-defined in units represented by another frame of reference) so that sources 36 - 40 come to be located where the corresponding open circles are illustrated. Sources 36 - 40 can then be fired again in a desired sequence. The movements and firings can be performed as many times as may be desirable or necessary to obtain the images that are sought.
FIG. 6 is a schematic diagram that illustrates an embodiment in which the satellite x-ray sources comprise a plurality of discrete individual sources. In FIG. 6 , ten individual sources, labeled respectively 21 through 30 , are provided instead of the ten sources 31 - 40 illustrated in FIG. 5 .
While FIG. 5 and FIG. 6 show a total of ten satellite x-ray sources as illustrative embodiments, the number of sources in a satellite x-ray source can be fewer than ten or greater than ten, as individual designs may require, or as may be found to be useful. The number ten is to be understood simply as a useful number for explanation of the apparatus and the method, and is not limiting. Any convenient number of sources can be provided in the apparatus.
Scatter Compensation in Tomosynthesis
The term “scatter” is commonly used for x-rays that are scattered in tissues and that are detected by the image receptor (the film screen or the digital detector in modern equipment). This x-ray scatter carries incorrect positional information and it degrades the contrast of radiographic images. Scatter is known to be detrimental to image quality. Aggressive measures are taken to suppress its effect in mammography and radiography by using anti-scatter grids. Software based techniques for correcting for the effects of scatter in radiographic imaging have been described. Breast and non-mammographic tomosynthesis would benefit from numerical algorithms and techniques that correct for the effects of scatter. However, such techniques will require accurate estimation of scatter that could vary substantially with each breast or other body part of a patient. However, unlike mammography and radiography, current implementations of digital tomosynthesis do not use an anti-scatter grid and they do not implement numerical scatter correction algorithms to counter the deleterious effect of x-ray scatter.
In another preferred embodiment we perform x-ray scatter correction. In this approach we use data from mammography to correct for scatter in tomosynthesis. The current trend is to perform mammography and tomosynthesis with the same system that is capable of performing both tests. Typically, this is implemented by acquiring a tomosynthesis projection sequence either preceding or following a single standard digital radiograph or digital mammogram. During the standard digital radiograph or digital mammogram the anti-scatter grid is in place so as to produce a substantially scatter-reduced image (also referred to as a “reduced x-ray scatter image”). An image produced without using scatter reduction methods will be termed a “full x-ray scatter image.” However, during digital tomosynthesis acquisition the anti-scatter grid is moved out of the x-ray beam to ensure that the anti-scatter grid does not cut-off the x-ray beam during projection acquisition at oblique angles. It is expected that one will be able to utilize the “reduced x-ray scatter image” from the digital radiograph or digital mammogram in combination with the “full x-ray scatter image” from the digital tomosynthesis acquisition that is acquired at a projection angle closest to the digital radiograph or digital mammogram to provide an a priori estimate of scatter for that projection angle. Subsequently, estimates for other projection angles of the tomosynthesis acquisition can be inferred using either analytical approaches that are based on pre-determined variation of scatter with projection angle as described in Sechopoulos, I., S. Suryanarayanan, S. Vedantham, C. J. D'Orsi, and A. Karellas, Scatter radiation in digital tomosynthesis of the breast . Med Phys, 2007. 34(2): p. 564-76, or using accelerated Monte Carlo based approaches that use the a priori information. The position dependent x-ray scatter estimate for each projection angle thus determined can be used for numerical scatter-correction techniques such as those based on convolution approaches, deconvolution approaches and iterative methods.
An important aspect in our system and method is the use of the digital mammography image at zero-degree projection angle which has reduced scatter due to the presence of an anti-scatter grid, and we deduce the scatter content for the zero-degree tomosynthesis projection, wherein the anti-scatter grid not present. Once the scatter content at zero-degree tomosynthesis projection is determined, the scatter-content at all other tomosynthesis projection angles can be determined using pre-computed or analytically modeled scatter variation with projection angle.
Sparse Stationary X-Ray Source Array
During initial development of the stationary x-ray source array technology, it may not be cost efficient to produce a large number of x-ray focal spots that constitute the array or it may not be feasible to position the x-ray focal spots close enough to provide adequate angular sampling. Hence, it is expected that one can use a sparse stationary source array comprising a few focal spot sources that can be rotated with reference to the object for tomosynthesis projection acquisition. In addition, the use of AABM is expected on such a stationary source array which can also be modulated as a function of its rotation about the object.
An advantage of a sparse satellite x-ray source array is that its use limits the required range of mechanical movement of the x-ray source, which could improve the use of “step-and-shoot” methods. For example, one could acquire multiple projections corresponding to the location of each source position with the satellite array situated in a first position. One could then rotate the array to the next angular position and the process repeated. This can reduce blurring caused by motion vibrations and angular movement of the x-ray source, because fewer angular transits would be required to obtain a full set of images.
Combined X-Ray Tube and Stationary X-Ray Source Array
Currently, stationary x-ray source arrays cannot achieve x-ray fluence rates that are as high as that provided by conventional x-ray tubes. Hence, we describe using a conventional x-ray tube for the central (zero-degree) projection and stationary x-ray source for other oblique projections. The conventional x-ray tube will also be used for standard projection imaging such as digital radiography or digital mammography as conventional x-ray tubes have demonstrated the capacity to provide the necessary x-ray fluence rate for such applications. This approach also enables the virtually concurrent acquisition of a conventional mammographic and tomosynthesis image without repositioning the object being imaged. This allows for improved image fusion between the digital radiograph and digital mammogram with the reconstructed tomographic dataset that is free of spatial misregistration due to repositioning of the object being imaged.
An advantage of using a conventional x-ray tube for the central (zero-degree) projection is that it allows the use of high fluence imaging needed for standard projection imaging such as digital radiography and digital mammography within an acceptable time frame. Also, the described configuration overcomes blurring due to mechanical movement of the x-ray source. In addition the apparatus and method are also suitable for contrast-enhancement imaging of the object or anatomy, with or without the use of dual-energy technique, wherein images are acquired after injection of contrast media such as intravenously injected iodinated contrast. The described approach also allows for the acquisition of rapid stereoscopic views by using two of the satellite sources to acquire two views that can be viewed in stereo mode. Alternatively, the conventional x-ray tube can provide one image, while one of the satellite sources can provide the second image so that a stereoscopic image pair is obtained and can be viewed in stereo mode. Also, the described approach can be used for tissue sampling such as needle-core biopsy using stereotactic localization, wherein at least one of the satellite sources is used to acquire one of the two views. Alternatively, both views for stereotactic localization can be obtained using satellite sources.
Scatter Correction in Digital Tomosynthesis
Currently digital tomosynthesis methods do not use any technique for reducing x-ray scatter such as an anti-scatter grid due to grid-cutoff. However, standard projection imaging methods use an anti-scatter grid to reduce x-ray scatter. The combination of digital tomosynthesis with standard digital x-ray imaging appears to be desirable clinically. In such applications, it is expected that the standard digital x-ray imaging acquired with the anti-scatter grid will provide an estimate of “reduced x-ray scatter image” and that the image acquired at a projection angle closest to the standard digital x-ray imaging during digital tomosynthesis acquisition without the anti-scatter grid will provide an estimate of “full x-ray scatter image.” It is expected that these two images at different x-ray scatter conditions can be used to arrive at an estimate of the position-dependent x-ray scatter content for tomosynthesis projection at that projection angle. Position-dependent x-ray scatter content at each tomosynthesis projection angle can then be estimated either analytically using pre-determined numerical methods or using Monte Carlo techniques. Once the position-dependent x-ray scatter content at each projection angle has been estimated, they are used as a priori information for numerical scatter correction techniques that are based on convolution approaches, deconvolution approaches or iterative approaches.
An advantage of this feature is that X-ray scatter correction can provide for improved contrast and can reduce artifacts in the image. We are not aware of any prior art that utilizes scatter information under two conditions, i.e., with and without an anti-scatter grid to obtain scatter estimates for scatter correction.
Apparatus
FIG. 7 is a schematic diagram that illustrates the components of an apparatus according to principles of the invention and the interactions among the components. As illustrated in FIG. 7 , an x-ray-based apparatus 710 such as is shown in any of FIG. 1 , FIG. 2 , FIG. 3 , FIG. 4 , FIG. 5 , or FIG. 6 is provided to perform the positioning of x-ray sources and an object to be examined A controller 720 is provided that communicates bi-directionally with the apparatus 710 . The controller 720 controls the activities of the apparatus 710 , and receives data from one or more detectors in the apparatus 710 . A computational device 730 communicates with the controller 720 , to direct the controller to control the apparatus 710 , and to receive from the controller 720 data to be process to generate the one of more stereoscopic, radiographic and tomographic images of the object or interest. The computational device 730 is in one embodiment a general purpose programmable computer provided with instructions recorded on a machine readable medium, and includes a memory upon which the data and/or the generated images can be recorded. The computational device 730 communicates with a display 740 , which can display one or more generated images to a user. The display can have one or more display screens, and can operate so as to provide a 3-D stereoscopic image if and when such an image is provided for display. The computational device 730 also includes a user interface that permits a user to initiate operation of the apparatus, and permits a user to request that results be provided as any of a displayed image, a recorded image, recorded data, and data and/or images to be provided to a user at a remote location.
Application
The invention described herein is directly applicable to digital breast tomosynthesis and digital chest tomosynthesis, which are considered as highly-promising candidates for clinical success.
Definitions
Recording the results from an operation, data acquisition, or computation, such as for example, recording results at a particular frequency or wavelength, is understood to mean and is defined herein as writing output data in a non-transitory manner to a storage element, to a machine-readable storage medium, or to a storage device. Non-transitory machine-readable storage media that can be used in the invention include electronic, magnetic and/or optical storage media, such as magnetic floppy disks and hard disks; a DVD drive, a CD drive that in some embodiments can employ DVD disks, any of CD-ROM disks (i.e., read-only optical storage disks), CD-R disks (i.e., write-once, read-many optical storage disks), and CD-RW disks (i.e., rewriteable optical storage disks); and electronic storage media, such as RAM, ROM, EPROM, Compact Flash cards, PCMCIA cards, or alternatively SD or SDIO memory; and the electronic components (e.g., floppy disk drive, DVD drive, CD/CD-R/CD-RW drive, or Compact Flash/PCMCIA/SD adapter) that accommodate and read from and/or write to the storage media. Unless otherwise explicitly recited, any reference herein to “record” or “recording” is understood to refer to a non-transitory record or a non-transitory recording.
As is known to those of skill in the machine-readable storage media arts, new media and formats for data storage are continually being devised, and any convenient, commercially available storage medium and corresponding read/write device that may become available in the future is likely to be appropriate for use, especially if it provides any of a greater storage capacity, a higher access speed, a smaller size, and a lower cost per bit of stored information. Well known older machine-readable media are also available for use under certain conditions, such as punched paper tape or cards, magnetic recording on tape or wire, optical or magnetic reading of printed characters (e.g., OCR and magnetically encoded symbols) and machine-readable symbols such as one and two dimensional bar codes. Recording image data for later use (e.g., writing an image to memory or to digital memory) can be performed to enable the use of the recorded information as output, as data for display to a user, or as data to be made available for later use. Such digital memory elements or chips can be standalone memory devices, or can be incorporated within a device of interest. “Writing output data” or “writing an image to memory” is defined herein as including writing transformed data to registers within a microcomputer.
“Microcomputer” is defined herein as synonymous with microprocessor, microcontroller, and digital signal processor (“DSP”). It is understood that memory used by the microcomputer, including for example instructions for data processing coded as “firmware” can reside in memory physically inside of a microcomputer chip or in memory external to the microcomputer or in a combination of internal and external memory. Similarly, analog signals can be digitized by a standalone analog to digital converter (“ADC”) or one or more ADCs or multiplexed ADC channels can reside within a microcomputer package. It is also understood that field programmable array (“FPGA”) chips or application specific integrated circuits (“ASIC”) chips can perform microcomputer functions, either in hardware logic, software emulation of a microcomputer, or by a combination of the two. Apparatus having any of the inventive features described herein can operate entirely on one microcomputer or can include more than one microcomputer.
General purpose programmable computers useful for controlling instrumentation, recording signals and analyzing signals or data according to the present description can be any of a personal computer (PC), a microprocessor based computer, a portable computer, or other type of processing device. The general purpose programmable computer typically comprises a central processing unit, a storage or memory unit that can record and read information and programs using machine-readable storage media, a communication terminal such as a wired communication device or a wireless communication device, an output device such as a display terminal, and an input device such as a keyboard. The display terminal can be a touch screen display, in which case it can function as both a display device and an input device. Different and/or additional input devices can be present such as a pointing device, such as a mouse or a joystick, and different or additional output devices can be present such as an enunciator, for example a speaker, a second display, or a printer. The computer can run any one of a variety of operating systems, such as for example, any one of several versions of Windows, or of MacOS, or of UNIX, or of Linux. Computational results obtained in the operation of the general purpose computer can be stored for later use, and/or can be displayed to a user. At the very least, each microprocessor-based general purpose computer has registers that store the results of each computational step within the microprocessor, which results are then commonly stored in cache memory for later use.
Many functions of electrical and electronic apparatus can be implemented in hardware (for example, hard-wired logic), in software (for example, logic encoded in a program operating on a general purpose processor), and in firmware (for example, logic encoded in a non-volatile memory that is invoked for operation on a processor as required). The present invention contemplates the substitution of one implementation of hardware, firmware and software for another implementation of the equivalent functionality using a different one of hardware, firmware and software. To the extent that an implementation can be represented mathematically by a transfer function, that is, a specified response is generated at an output terminal for a specific excitation applied to an input terminal of a “black box” exhibiting the transfer function, any implementation of the transfer function, including any combination of hardware, firmware and software implementations of portions or segments of the transfer function, is contemplated herein, so long as at least some of the implementation is performed in hardware.
Theoretical Discussion
Although the theoretical description given herein is thought to be correct, the operation of the devices described and claimed herein does not depend upon the accuracy or validity of the theoretical description. That is, later theoretical developments that may explain the observed results on a basis different from the theory presented herein will not detract from the inventions described herein.
Any patent, patent application, or publication identified in the specification is hereby incorporated by reference herein in its entirety. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material explicitly set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the present disclosure material. In the event of a conflict, the conflict is to be resolved in favor of the present disclosure as the preferred disclosure.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be affected therein without departing from the spirit and scope of the invention as defined by the claims.
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Systems and methods for providing radiographic, stereoscopic and tomographic images of an object of interest. Examples of objects of interest are body parts of living beings, such as the human breast and the human chest. The apparatus includes a high-fluence rate x-ray source and a plurality of satellite x-ray sources operating at lower fluence rate than the high-fluence rate source. A controller controls the operation and locations of the sources, and the operation of a detector. The method provides procedures in which the operation of the high-fluence source and the satellite sources are individually controlled as to location and orientation relative to the object of interest. In some operations, one satellite source may be operating while another satellite source may be repositioning. By proper control, a reduced x-ray dose and reduced operating time can be attained, thereby improving image quality, patient care, and patient experience.
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RELATED APPLICATIONS
[0001] This application is a continuation of application serial number PCT/US12/27259, filed on Mar. 1, 2012 which claims priority from provisional application Ser. No. 61/448,459, filed on Mar. 2, 2011 which are incorporated by reference as if fully set forth herein.
BACKGROUND
[0002] The present disclosure is directed to repairing blood vessel defects, such as aneurysms, and other physiological defects or cavities formed in lumens, tissue, and the like, and, more particularly, to an endovascular implantable device and related endoluminal delivery procedure and deployment techniques.
[0003] Cranial aneurysms occur when a weakened cerebral blood vessel (root vessel) locally expands to form a bulge or balloon-like enlargement in the vessel wall. These aneurysms can occur along a vessel wall or at locations of vessel branches, such as a T-intersection or V-intersection.
[0004] Currently, options for the treatment of brain aneurysms are limited. In one technique, the cranium is opened and a clip is placed at the aneurysm neck to cut off blood flow from the root vessel, thereby reducing swelling and stopping expansion. In another technique, the interior of the aneurysm is accessed by way of a cranial artery, which in turn is reached with a device inserted into the femoral artery. In this technique, coiling material is inserted into the aneurysm, thereby causing clotting which closes off the aneurysm. Both techniques have drawbacks. Opening the cranium always entails some risk. Some locations in the cranium are difficult or impossible to access from the outside. On the other hand, causing clotting in the aneurysm can increase the mass and size of the aneurysm, causing it to press against delicate and critical tissue, and causing further damage.
[0005] Devices and techniques have been developed to facilitate treatment of aneurysms. The application herein is a joint inventor on the following U.S. Patent Publication Nos. 2006/0264905 (“Improved Catheters”), 2006/0264907 (“Catheters Having Stiffening Mechanisms”), 2007/0088387 (“Implantable Aneurysm Closure Systems and Methods”), and 2007/0191884 (“Methods and Systems for Endovascularly Clipping and Repairing Lumen and Tissue Defects”). All of these published applications are incorporated by reference herein in their entirety, to the extent legally possible.
[0006] For example, referring to FIGS. 1A and 1B , which are reproduced from U.S. Patent Publication No. 2007/0191884, shown therein is a device 130 having a patch or closure structure 131 mounted to or associated with two anchoring structures 132 , 133 . The closure structure 131 is supported by a framework structure 134 that is provided at least in a perimeter portion and is attached to the closure structure 131 by means of bonding, suturing, or the like. The framework structure 134 is mounted to or associated with the wing-like anchoring structures 132 , 133 . These anchoring structures 132 , 133 in a deployed condition are designed so that at least a portion thereof contacts an inner wall of an aneurysm or an internal wall of an associated blood vessel following deployment.
[0007] As can be seen in FIG. 1A , the anchoring structures 132 , 133 are generally formed to curve outwardly from an attachment joint 135 to the framework structure 134 and then back inwardly toward one another at the end remote from the attachment point 135 . The anchoring loops 132 , 133 are generally of the same configuration and same dimension and are located opposite one another as shown in FIG. 1A .
[0008] FIG. 1B illustrates a similar device having a closure structure 136 with anchoring structures 137 , 138 that attach to or project from a framework structure 139 along opposed, lateral edges of the framework structure. The anchoring structures 137 , 138 as illustrated in FIG. 1B are gently curved and, at their terminal sections, extend beyond corresponding terminal sections of the framework structure and the closure structure. The closure and framework structures in this embodiment are generally provided having a surface area that exceeds the surface area of the aneurysm neck, and the anchoring structures generally reside inside the aneurysm following placement of the device. In this configuration, the anchoring structures exert lateral and downward force on the closure structure so that it generally conforms to the profile of the vessel wall at the site of the aneurysm, thereby sealing the neck of the aneurysm from flow in the vessel and providing reconstruction of the vessel wall at the site of the aneurysm. Unfortunately, framework structure 139 and structures 137 and 138 are mismatched in length and are too stiff to apply the mutually opposing forces on interposed tissue, necessary to form an effective clip. In addition this structure is too stiff and expanded to be able to collapse into a configuration that can be fit into the space available in a placement device, small enough to be introduced into the smaller cranial blood vessels. Moreover, its boxy shape makes it difficult to maneuver as is necessary to effect placement into an aneurysm.
[0009] FIGS. 1C-1F schematically illustrate the devices of FIGS. 1A and 1B deployed at the site of an aneurysm. A bulge in the blood vessel B forms an aneurysm A. As shown in FIGS. 1C and 1D , when the device 130 is deployed across the neck of and within the aneurysm A, the closure structure 131 is positioned to cover the opening of the aneurysm and the anchoring structures 132 and 133 are retained inside and contact an inner aneurysm wall along at least a portion of their surface area. In this fashion, the closure structure 131 and the framework portion 134 are supported across the aneurysm opening and are biased against the neck of the aneurysm from outside the aneurysm.
[0010] In the embodiment illustrated in FIGS. 1C and 1D , the closure structure 131 and the framework portion 134 are deployed outside the internal space of the aneurysm. In an alternative embodiment illustrated in FIG. 1E , the closure structure 131 and the framework portion 134 are supported across the aneurysm opening and biased against the neck of the aneurysm from inside the aneurysm.
[0011] FIG. 1F illustrates an alternative deployment system and methodology, wherein a device having at least two anchoring structures is deployed such that the closure structure 131 is positioned to cover the opening of the aneurysm, and the anchoring structures 132 , 133 are positioned outside the aneurysm and contact an inner blood vessel wall B in proximity to the aneurysm. In this embodiment, the anchoring structures 132 , 133 may be generally sized and configured to match the inner diameter of the vessel in proximity to the neck of the aneurysm so that following deployment the anchoring structures contact the vessel wall in a substantially continuous manner without straining or enlarging the vessel wall in the area of the aneurysm. In all of these embodiments, following placement of the device, the closure structure substantially covers the aneurysm neck to effectively repair the vessel defect. The anchoring structures do not substantially interfere with flow of blood in the vessel.
[0012] As can be seen in the foregoing, the structures may be difficult to place, particularly in the circuitous blood vessel network of the brain. For the typical aneurysm, extending in a perpendicular manner from its root blood vessel, it may be a challenge to insert the structure into the aneurysm. Moreover, for the device to seal or close the aneurysm, the anchoring structures must mutually press against the aneurysm sides. If one side wall of an aneurysm is not well suited for supporting an anchoring structure, the anchor for the opposite side will not be well supported to provide sufficient pressure on this opposite side wall. This problem drives the design of anchor structures 132 and 133 to be larger, to facilitate receiving sufficient support from the aneurysm interior surface. This, in turn, has the potential to create a mass effect problem, in which the mass of the structures 132 and 133 , plus any clotting that occurs around them, causes the aneurysm to become more massive, potentially pressing against delicate nervous system tissue as a result.
[0013] Moreover, the situation is even more difficult for aneurysms formed at the intersection of vessels, such as a T-intersection or V-intersection. FIG. 1G illustrates a saccular bifurcation aneurysm 150 appearing at the intersection of two vessels 152 , 154 , branching from a stem vessel 156 . Cerebral bifurcation aneurysms are commonly found at the middle cerebral artery, internal carotid artery, anterior communicating artery, basilar artery, posterior communicating artery, and other locations.
[0014] Typically, to place device 130 into a blood vessel of the brain requires a number of steps. First, an incision is made into the femoral artery and a sheath is introduced, extending approximately to the aorta. A first guide catheter is inserted through the sheath and extended up into the carotid artery. A second guide catheter is coaxially introduced through the first guide catheter and extended up into the target aneurysm. Both guide catheters are introduced using a guide wire having a steerable tip of either stainless steel or nitinol. Then, microcatheter introducer is inserted through the guide catheter, to the aneurysm, and device 130 is placed at the aneurysm site. Heretofore, however, once reaching the aneurysm there has been no effective method for positioning a device that requires precise positioning. A device that would require a definite orientation, at least partially inside the aneurysm, presents particular challenges in positioning during implantation
[0015] Another difficulty in delivering a complex implant into an aneurysm is the lack of space to pack such an implant in a lumen at the end of a microcatheter. Any such device must fold into a cylinder having an internal diameter on the order of 1 mm and a length of about 10 mm. Upon delivery it must expand to anchor itself in place and to seal an area that could be as large as 10 mm 2 . The seal over the neck of the aneurysm although thinner than 1 mm, must be strong enough to affirmatively occlude the aneurysm, with a very high degree of certainty.
SUMMARY
[0016] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
[0017] In a first separate aspect, the present invention may take the form of an aneurysm closure device having a pair of retention clips joined together. Each of the clips has an aneurysm anchor joined to a root-vessel anchor, and is made of material having a resilient installed state, in which the aneurysm anchor and the root-vessel anchor are urged together, thereby squeezing and being retained by interposed tissue. Also, an aneurysm seal, to seal an aneurysm, bridges the clips, causing the aneurysm to atrophy.
[0018] In a second separate aspect, the present invention is a method of treating an aneurysm in a patient's brain, extending from a root blood vessel. The method uses an aneurysm closure device that includes a pair of retention clips, joined together. Each clip has an aneurysm anchor coupled to a root-vessel anchor, and is made of material having a resilient installed state, in which the aneurysm anchor and the root-vessel anchor are urged together, thereby squeezing and being retained by any interposed material. An aneurysm seal, bridges the clips. The aneurysm closure device is implanted so that it seals the aneurysm by positioning the aneurysm anchors in opposed positions inside the aneurysm and the root vessel anchors inside the root blood vessel so that each the aneurysm anchor is urged toward its coupled root-vessel anchor, thereby retaining the aneurysm closure device by pressure placed by the clips on the interposed aneurysm and root vessel tissue, and thereby placing the seal over the aneurysm, reducing blood flow to the aneurysm and causing eventual atrophy of the aneurysm.
[0019] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] Exemplary embodiments are illustrated in referenced drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
[0021] FIG. 1A illustrates an enlarged schematic front isometric view of a known implantable device in a deployed condition;
[0022] FIG. 1B illustrates an enlarged schematic front isometric view of another known implantable device in a deployed condition;
[0023] FIGS. 1C , 1 D, 1 E, and 1 F schematically illustrate the devices of FIGS. 1A and 1B deployed at the site of an aneurysm;
[0024] FIG. 1G illustrates a saccular bifurcation aneurysm;
[0025] FIG. 2A is a sectional side view of an aneurysm closure device, according to the present invention, installed in the neck of an aneurysm that has developed at the side of a blood vessel.
[0026] FIG. 2B is a sectional side view of the aneurysm closure device of FIG. 2A , according to the present invention, installed in the neck of an aneurysm that has developed at a Y-intersection of blood vessels.
[0027] FIG. 3 is an isometric view of the aneurysm closure device of FIG. 2A .
[0028] FIG. 4 is an isometric view of an implantation catheter, according to the present invention, with the closure device of FIG. 2A retracted.
[0029] FIG. 5 is an isometric view of the catheter of FIG. 4 , with the closure device of FIG. 2A exposed.
[0030] FIG. 6 is an isometric exploded view of the user control portion of the catheter of FIG. 4 .
[0031] FIG. 7 is a sectional side view of the distal end of the catheter of FIG. 4 , with the closure device of FIG. 2A retracted.
[0032] FIG. 8 is an isometric view of the distal portion of the positioning assembly of FIG. 4 , with the closure device of FIG. 2A extended.
[0033] FIG. 9 is a cross-sectional view of the distal portion of FIG. 8 , taken at view line 9 - 9 .
[0034] FIG. 10 is a cross-sectional view of the distal portion of FIG. 8 , taken at view line 10 - 10 .
[0035] FIG. 11 is a cross-sectional view of the distal portion of FIG. 8 , taken at view line 11 - 11 .
[0036] FIG. 12A is a side view of the user control of FIG. 6 , set in a neutral position.
[0037] FIG. 12B is a side view of the user control of the distal end of FIG. 7 , corresponding to the user control setting of FIG. 12A .
[0038] FIG. 13A is a side view of the user control of FIG. 6 , set in a skewed position.
[0039] FIG. 13B is a side view of the user control of the distal end of FIG. 7 , corresponding to the user control setting of FIG. 13A .
[0040] FIG. 14A is a side view of the user control of FIG. 6 , set in a position skewed opposite to that of FIG. 13A .
[0041] FIG. 14B is a side view of the user control of the distal end of FIG. 7 , corresponding to the user control setting of FIG. 12A .
[0042] FIG. 15A is an isometric view of a work piece shown connected to the distal end of FIG. 7 for ease of presentation and representing a stage in the manufacturing of the closure device of FIG. 3 .
[0043] FIG. 15B is a detail view of a portion of FIG. 15A , as indicated by circle 15 B, in FIG. 15A .
[0044] FIG. 15C is an isometric view of a work piece shown connected to the distal end of FIG. 7 for ease of presentation and representing a further stage in the manufacturing of the closure device of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures or components or both associated with endovascular coils, including but not limited to deployment mechanisms, have not been shown or described in order to avoid unnecessarily obscuring descriptions of the embodiments.
[0046] Unless the context requires otherwise, throughout the specification and claims that follow, the word “comprise” and variations thereof, such as “comprises” and “comprising” are to be construed in an open inclusive sense, that is, as “including, but not limited to.” The foregoing applies equally to the words “including” and “having.”
[0047] Reference throughout this description to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment.
[0048] Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0049] The present disclosure is directed to closing a bulge or aneurysm formed in blood vessel, such as an artery or vein (referred to more generally herein as “vessel”), in a manner that does not suffer from some of the drawbacks of prior art methods. For example, in the prior art method involving the insertion of a wire coil into the aneurysm, the resultant blood clot can create problems through its mass and the possibility of pressing against nearby nerves. In addition, the wire coil can have the effect of keeping the neck open, possibly causing another aneurysm to form.
[0050] The embodiments of the present disclosure combine the closure structure and the anchoring structure into a single unit to improve compactness, allow delivery into the tortuous intracranial circulation system via a microcatheter, and to improve the aneurysm neck closure. In addition, the embodiments of the present disclosure provide enhanced rotation control and placement of the device within the aneurysm via two attachment points for a microcatheter. Moreover, markers can be used at the junctions of the device structure to aid in tracking the movement of the closure device during insertion and placement.
[0051] Referring to FIG. 2A , a preferred embodiment of an aneurysm closure device 10 is shown in its implanted environment of an aneurysm 12 attached to a root vessel 14 . FIG. 2B shows the device 10 , implanted environment, on an aneurysm that has developed at a Y-intersection of blood vessels. FIG. 3 shows a more detailed perspective view of closure device 10 . In FIG. 2A , aneurysm closure device 10 is held in place by four anchors: A first aneurysm anchor 16 A and a first root vessel anchor 18 A mutually anchor closure device 10 to a distal side of the aneurysm 12 , while a second aneurysm anchor 16 B and a second root vessel anchor 18 B, mutually anchor closure device 10 on a proximal side of the aneurysm 12 . Referring to FIG. 3 , it is seen that in the installed state of FIG. 2A , a seal 20 is placed over the neck of aneurysm 12 , thereby preventing further blood flow into aneurysm 12 and causing it to atrophy over time.
[0052] First anchors 16 A and 18 A act as a first clip, mutually applying gentle pressure toward each other, thereby clipping about the interposed tissue. In similar manner, second anchors 16 B and 18 B act as a second clip. Working together, anchors 16 A, 18 A, 16 B and 18 B hold the seal 20 in place, thereby blocking the flow of blood into aneurysm 12 .
[0053] Closure device 10 includes a wire frame 22 , which is made of nitinol, or some other shape-memory material. Prior to use, closure device 10 is maintained at a temperature below human body temperature, thereby causing wire frame to assume the shape shown in FIG. 3 , when first pushed out of terminal lumen 56 . In one preferred embodiment, after warming to 37 C, however, anchors 16 A and 18 A, are urged together, as are anchors 16 B and 18 B, thereby more securely clipping to the interposed tissue. In another preferred embodiment, however, the natural spring force of the nitinol causes device 10 to expand when it is pushed out of fossa 56 , and it retains this shape during positioning and use. A set of eyeholes 24 are defined by frame 22 and expanded poly tetrafluoroethylene (ePTFE) thread or fiber 26 is threaded into these eyeholes 24 to form a lattice. The eyeholes 24 are filled with gold solder ( FIG. 15B ), thereby anchoring thread 26 and closing eyeholes 24 . Accordingly, although materials may be useable as thread 26 whatever material is used must be capable of withstanding the temperature of molten gold solder, which is typically 716° C. The ePTFE lattice work 26 is then coated with silicone 28 , which in one preferred embodiment is cured in situ to form the seal 20 . In another preferred embodiment, sheets of silicone are cut to the correct dimensions and adhered together about the ePTFE lattice 26 . In the embodiment shown, silicone 28 is placed on the aneurysm anchors 16 A and 16 B, but in an alternative embodiment, the ePTFE portion on anchors 16 A and 16 B are there to complete the threading arrangement, but are not coated with silicone. In another alternative preferred embodiment more, and smaller, eyeholes 24 are defined. In a preferred embodiment, two spots of radiopaque material 30 are placed at the tip of each aneurysm anchor 16 A and 16 B and one spot of radiopaque material 30 is placed at the tip of each root vessel anchor 18 A and 18 B. Accordingly, a surgeon placing closure device 10 can determine the position of closure device 10 , through a sequence of X-ray images, relative to the contours of the aneurysm 12 , which is shown by the use of a radiopaque dye, placed into the bloodstream.
[0054] In an alternative preferred embodiment at least some of the anchors, serving the function of anchors 16 A- 18 B, are made of a thin sheet of nitinol, or a thin sheet of nitinol covered with a biocompatible silicone, or polymeric material, for forming a good grip on the tissue it contacts. In yet another embodiment, at least some of the anchors are made entirely of polymeric material. In an additional preferred embodiment, ePTFE thread 26 lattice, is replaced with metal filigree, made of a metal such as gold, having a high melting point. In addition, there is a broad range of engineered materials that can be created for this type of purpose. In yet another preferred embodiment, anchors, serving the function of anchors 16 A- 18 B, are made of wire loops or arcs, some of which support an ePTFE reinforced silicone barrier, thereby providing a closure mechanism for an aneurysm.
[0055] Referring to FIGS. 4-14B , prior to installation, closure device 10 forms a part of a micro-catheter closure device installation assembly 40 , which although specifically adapted to install closure device 10 at an aneurysm also embodies mechanisms that could be used for other tasks, particularly in accessing tissue through a blood vessel. Assembly 40 comprises a micro-catheter subassembly 42 , and a user-control subassembly 44 . A first wire-head handle 46 A and a second wire-head handle 46 B, are attached to a first wire 48 A and a second wire 48 B, respectively.
[0056] Referring to FIGS. 7-14B , in micro-catheter subassembly 42 , wires 48 A and 48 B pass through a flexible tube 50 , which has an exterior diameter of about 1.5 mm, and which has a hydrophilic exterior surface, to aid in progressing toward a blood vessel destination. Tube 50 is divided into a proximal single lumen extent 52 , near-distal dual lumen extent 54 , and a distal fossa or wide-lumen extent 56 . This construction permits for the control of the shape and orientation of distal portion of tube 50 , and for the positioning of closure device 10 , after it has been pushed out of fossa 56 . As shown in FIG. 13A and 13B , if the first wire-head handle 46 A is retracted relative to second wire-head handle 46 B, then distal fossa 56 bends towards handle 46 A. Likewise, as shown in FIGS. 14A and 14B , if the second wire-head handle 46 B is retracted relative to first wire-head handle 46 A, then distal fossa 56 bends towards handle 46 B. The orientation of fossa 56 , and the direction it turns to when handle 46 A or 46 B is retracted, can be changed by rotating the wire-head handles 46 A and 46 B, together. After closure device 10 is pushed out of fossa 56 , it responds in like manner, bending toward wire-head handle 46 A, when handle 46 A is retracted, and toward handle 46 B, when handle 46 B is retracted. It can be rotated, and the direction that it bends when wire 46 A or 46 B is pulled can be determined, by rotating the handles 46 A and 46 B, together. This freedom in positioning is important during the implantation process, when as shown in FIGS. 2A and 2B anchors 16 A and 16 B must be maneuvered through the neck of the aneurysm 12 , and positioned so that they extend along the same dimension as root vessel 14 . The radiopaque markings 30 ( FIG. 3 ) are invaluable during this process.
[0057] Referring now to FIG. 6 , subassembly 42 is threaded through an end cap 60 , and passes into a transparent chamber 62 , where wires 48 A and 48 B, emerge from tube 50 , pass through a slider 64 and are separately anchored in handles 46 A and 46 B, respectively. The travel extent of slider 64 is limited by a stop pin 66 and a slot 68 .
[0058] Wires 48 A and 48 B each include a region 70 ( FIGS. 7 and 8 ) that is susceptible to electrolytic disintegration. To detach closure device 10 , after placement, an electric current is passed through wires 48 A and 48 B, causing regions 70 to electrolytically disintegrate, freeing closure device 10 from wires 48 A and 48 B, so that it can be left in place in its target location, sealing aneurysm 12 . In a preferred embodiment, handles 46 A and 46 B each includes an electrical contact connected to wire 48 A and 48 B, respectively, for attaching to a source of electricity for performing the above-described step.
[0059] Subassembly 42 is introduced into the femoral artery and guided through the carotid artery into the brain's arterial system, and further guided to the aneurysm 12 . At this point closure device 10 is pushed out of fossa 56 , anchors 16 A and 16 B are guided into aneurysm 12 , and anchors 18 A and 18 B are positioned in root artery 14 . Then a pulse of electricity severs closure device 10 from wires 48 A and 48 B and closure device 10 is installed in place.
[0060] Wires 48 A and 48 B are made of stainless steel alloy 304 , which may also be referred to as alloy 18-8. This material is coated with poly tetrafluoroethylene, except for at detachment points 70 and the points where they are connected to a source of electricity. The nitinol alloy that frame 22 ( FIG. 3 ) is made of is 54.5% to 57% nickel, with the remainder titanium, which forms a super-elastic alloy. The introducer tube 50 is made of high density polyethylene, coated at the distal tip with a hydrophilic coating. Finally, the silicone 28 of the closure device 10 is silicone MED 4820 or MED-6640, which is a high tear strength liquid silicone elastomer, having a Shore A durometer reading of 20-40. A MED6-161 Silicone Primer is used to attach silicone 28 to Nitinol frame 22 .
[0061] While a number of exemplary aspects and embodiments have been discussed above, those possessed of skill in the art will recognize certain modifications, permutations, additions and sub-combinations, thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
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An aneurysm closure device having a pair of retention clips joined together. Each of the clips has an aneurysm anchor joined to a root-vessel anchor, and is made of material having a resilient installed state, in which the aneurysm anchor and the root-vessel anchor are urged together, thereby squeezing and being retained by interposed tissue. Also, an aneurysm seal, to seal an aneurysm, bridges the clips, causing the aneurysm to atrophy.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of virology, and more particularly to immunology, wherein a recombinant, non-segmented negative stranded RNA virus serves as a vector for the expression of functional human antibodies for use in the treatment of infectious diseases or cancer.
BACKGROUND OF THE INVENTION
[0002] It has been well over a decade since Cohen and Boyer first reported the use of bacterial plasmids as molecular cloning vectors; this marked the beginning of a new era in molecular biology and, historically, laid the foundation for what has been termed the “biotechnology industry.” Cohen and Boyer's cloning vector, pSC101, relative to the cloning vectors in circulation today, seems almost quaint—insertion of foreign DNA fragments into pSC101 was limited to a single restriction enzyme cleavage site and to Escherichia coli as a host. During the past decade, the art has had access to hundreds of molecular cloning vectors having nearly as much applicability and diversity as the number of vectors. Irrespective of the variety of such vectors, the typical objective remains the same: increased availability of a protein of interest that ordinarily is produced naturally in minute quantities.
[0003] In accordance with a typical strategy involving recombinant DNA technology, a DNA sequence which encodes a desired protein material (“cDNA”) is identified and either isolated from a natural source or synthetically produced. This piece of genetic material is ligated into a section of a small circular molecule of double stranded DNA. This circular molecule is typically referred to as a “DNA expression vector”.
[0004] The combination of the vector and the genetic material is referred to as a “recombinant”. The recombinant is isolated and introduced into a host cell and when the cellular DNA of the host cell replicates, the recombinant expression vector will also replicate. Accordingly, as the host cells grow and divide, there is a corresponding increase in cells containing the recombinant, which leads to the production (“expression”) of the protein material of interest. By subjecting the host cells containing the recombinant to favorable growth conditions, significant amounts of the host, and hence the protein of interest, are produced.
[0005] The vector plays a crucial role in determining the conditions under which expression of the genetic material will or will not occur. However, most of the vector manipulations are geared toward a single goal—increasing expression of a desired gene product, ie protein of interest. Stated again, most vector manipulation is conducted so that an “improved” vector will allow for production of a gene product at significantly higher levels when compared to a “non-improved” vector. Thus, while certain of the features/aspects/characteristics of one vector may appear to be similar to the features/aspects/characteristics of another vector, it is often necessary to examine the result of the overall goal of the manipulation—improved production of a gene product of interest.
[0006] A characteristic desirable for vectors is increased efficiency, that is, the ability to increase the amount of protein of interest. Such increased efficiency has several desirable advantages, including, but not limited to, reducing manufacturing costs and increasing purity of the protein product. Accordingly, there is a long sought need to significantly improve the current state of the art by developing expression vectors with such efficiency characteristics. The present invention has filled this long sought need by developing chimeric rabies virus expression vectors that express functional human antibodies.
[0007] Human rabies is a worldwide public health problem. Nearly half a million people receive annually rabies post-exposure prophylaxis (Steele, Rev. Infect. Dis. 10 (Suppl. 4): 585, 1988) which includes the use of anti-rabies virus immunoglobulin together with the administration of rabies vaccine (Wilde et al., Vaccine 7: 478, 1989). Equine anti-rabies immunoglobulin (ERIG) and human anti-rabies immunoglobulin (HRIG) which are currently used for rabies post-exposure prophylaxis are either associated with severe adverse effects or are, as in the case of HRIG, extremely expensive. There are also safety concerns for HRIG because it is prepared from pooled human sera and, therefore, could be potentially contaminated with human pathogens. The present invention provides for an alternative for the production of monoclonal antibodies by the insertion of the nucleotide sequences coding for heavy and light chains of these human monoclonal antibodies into suitable expression vectors and expressing the inserted protein-coding sequences in appropriate cells, preferably eukaryotic cells.
[0008] As a first step toward the production of safer reagents, several human monoclonal antibodies (h MAbs) to rabies virus have recently been made by fusion of Epstein-Barr virus (EBV)-transformed rabies virus- specific human B cells with mouse-human heterohybrid cells (Ueki, et al., J. Exp. Med. 171: 19, 1990; Champion, et al., J. Immunol. Methods 235: 81, 2000). Several of these human monoclonal antibodies neutralized a broad spectrum of rabies virus and were able to protect hamsters against a lethal rabies virus infection when administered after infection (Dietzschold, B., et al., J. Virol. 65: 3087, 1990) indicating their great utility for the rabies post-exposure treatment of humans. However, in order to be routinely used in rabies treatment, large quantities of these human monoclonal antibodies must be cost effectively produced. Because of low expression levels (˜1 mg/l) and instability, the use of mouse-human heterohybrid cells secreting these human monoclonal antibodies, is not feasible for mass production.
[0009] There is a great need for safer and more effective products, for example for the post-exposure prophylaxis of human rabies. The evidence of the present invention indicates that rabies virus neutralizing human monoclonal antibodies will replace the currently used human anti-rabies immunoglobulin (HRIG) or equine anti-rabies immunoglobulin (ERIG) as a safer and more effective treatment. The main advantages of these human monoclonal antibodies over HRIG or ERIG are high specific protective activity, invariability of biological activity, and lack of risk and adverse effects.
[0010] Hybridoma technology for production of human monoclonal antibodies has become relatively easy and several mouse-human heterohybrid cell lines that secrete rabies virus neutralizing human monoclonal antibodies have already been established (Ueki, et al., J. Exp. Med. 171: 19, 1990; Champion, et al., J. Immunol. Methods 235: 81, 2000). The problem regarding a cost effective production of human Monoclonal antibodies is overcome by taking advantage of recombinant DNA technology of the present invention.
[0011] The expression vector disclosed herein allows for a high yield production of functional antibody. Although antibodies require extensive post-translational processing to become bioactive, several mouse and human immunoglobulin (Ig) heavy (H) chain and light (L) chain genes have been cloned and recombined with a variety of vectors which were able to express functional antibodies in eukaryotic expression systems. The eukaryotic expression systems currently used include lymphoid and non-lymphoid mammalian cells (Ovens, R. J. and Young, R. J., J. Immunolo. Meth., 168, 149-165, 1994), insect cells (Liang, et al, Virol. 235, 252-260, 1997), and plants (Whitelam, et al, Biochem. Soc. Transactions, 22, 940-944, 1994). While some of these expression systems, in particular mouse myeloma cells transfected with plasmid vectors containing Ig H and Ig L chain genes, are able to produce high levels of antibody, the recombinant expression vector (SPBN, see FIG. 1) of the present invention offers several advantages. The modular genome organization of the SPBN vector readily allows genetic manipulations and insertion of Ig H and Ig L chain genes. In contrast, the current state of the art uses transfection and selection of stable antibody expressing cell lines, which is a time consuming process.
[0012] The genome of the SBPN vector is a negative sense single-stranded RNA, thus expression of foreign genes is very stable and recombination events do not occur. In comparison, many myeloma cells often undergo somatic hypermutation and, therefore, have to be constantly recloned to maintain expression of the antibody.
[0013] The viral expression vectors used to date are used only in a very few cell types. In contrast, the SPBN vector of the present invention is extremely versatile. Because it contains the Vesicular Stomatitis Virus (VSV) glycoprotein (G), this vector is polytropic and able to infect and replicate in almost every mammalian or avian cell.
[0014] Further, many DNA and RNA viruses that express antibody are cytopathic, thereby limiting the expression, and hence yield, of antibody. The SPBN vector is non-cytopathic and, therefore, allows infected cells to produce antibody over a long period of time.
[0015] Transfected myeloma cells, the current cell line used for expression of functional antibody, must replicate to high numbers in order to produce a large scale production of antibody. The SPBN expression vector of the present invention allows for a high number of tissue culture cells to be infected simultaneously, enabling production of large amounts of antibody within a short period of time. Therefore, the SPBN expression system is well suited for industrial antibody production.
[0016] Definitions
[0017] immunoglobulin means antibody
SUMMARY OF THE INVENTION
[0018] The present invention relates to an expression vector wherein a recombinant non-segmented negative-stranded RNA virus expresses a cDNA encoding an immunoglobulin. In one embodiment the immunoglobulin is a heavy chain. In another embodiment the immunoglobulin is a light chain. In another embodiment the cDNA encodes an immunoglobulin heavy chain and an immunoglobulin light chain. The present invention further relates to a method for expressing a functional immunoglobulin. A mammalian cell is infected with an expression vector wherein a recombinant non-segmented negative-stranded RNA virus expresses immunoglobulin heavy and light chains. The supernatants from the tissue culture cells are harvested, the virus is inactivated, and the supernatants are tested for the presence of neutralizing antibody.
[0019] A further embodiment of the present invention is a method for expressing a functional immunoglobulin wherein a mammalian cell is double-infected with expression vectors. One expression vector is a recombinant non-segmented negative-stranded RNA virus vector expressing an immunoglobulin heavy chain and the other expression vector is a recombinant non-segmented negative-stranded RNA virus vector expressing an immunoglobulin light chain. The supernatants from the mammalian cell tissue cultures are harvested, the virus is inactivated, and the supernatants are tested for the presence of neutralizing antibody. It is a further object of the present invention to present a method of treating a condition in which an antigen is recognized. A therapeutically effective amount of a purified antibody is administered to a mammal. The antibody binds to the antigen, thereby preventing a diseased state from persisting. In another embodiment the condition in which an antigen is recognized is treated by administering a therapeutically effective amount of a purified viral vector wherein a recombinant non-segmented, negative-stranded RNA virus vector expresses an antibody. The antibody is expressed in vivo and binds to the antigen, preventing a diseased state from persisting. The present invention further relates to a method of prophylactically preventing a condition in which an antigen is recognized. A therapeutically effective amount of a purified antibody is administered; the purified antibody binds to the antigen and prevents a diseased state from occurring. Another embodiment relates to administration of a therapeutically effective amount of a purified viral vector, wherein a recombinant non-segmented, negative-stranded RNA virus vector expresses an antibody. The antibody binds to the antigen and prevents a diseased state from occurring.
DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1. Schematic representation of the construction of the SPBN vector, expressing human IgG antibody genes. The glycoprotein (G) gene of rabies virus (RV) was replaced with a chimeric glycoprotein (G) which contains the ecto- and transmembrane domain of VSV glycoprotein fused to the cytoplasmic domain of RV glycoprotein. To obtain SPBN vectors expressing human IgG antibody the pseudo gene of RV (ψ) was replaced by the genes encoding the light (IgG 1), heavy (IgG h), or both light and heavy Ig chain resulting in the vectors SPBN−H, SPBN−L, and SPBN−H+L.
[0021] [0021]FIG. 2. A. Protein A Sepharose chromatography of human anti-rabies antibody JA-3.3A5 expressed in BSR cells by SPBN−H+L. The dashed line shows the protein concentration and the solid line the virus neutralizing titers in international units. (I.U.). B. A polyacrylamide gel electrophoresis of {fraction (1/100)} volume of the eluted fraction of human anti-rabies antibody JA-3.3A5 (FIG. 2A). The gel was stained with Coomassie Brillant Blue to visualize the protein bands.
DESCRIPTION OF THE INVENTION
[0022] Growing evidence suggests that certain human antibodies play an essential role in controlling infection, such as rabies virus (RV) or human immunodeficiency virus (HIV), (Baba, et al, Nature Medicine, 6:200-206, 2000), Habel, K., Bulletin of the World Health Organization, 38:383-7,1997), Serokowa, et al, przeglad Epidemiologiczny, 23:481-8,1969) Sziegoleit, A. and H. J. Gerth, Medizinische Mikrobiologie und Parasitologie, 218:24-31, (1971). In addition, it has been shown that antibodies directed against cancer cells play an important role in the therapy of a cancer patient (Gramatzki, M. and T. Valerius, Internist, 38:1055-62, 1997) Kishore, et al, Journal of the Association of Physicians of India, 26:479-84, 1978), (Ward, et al, lessons from the clinic Cancer Treatment Reviews, 23:305-19, 1997). The present invention is a new method to express a human antibody directed against RV glycoprotein (G) [JA-3.3A5 (3)] by a chimeric rabies virus. This vector allows for the expression of functional human immunoglobulin (IgG) heavy and light chains, as shown by rabies virus neutralization assays (see, infra). The data indicate that functional human antibodies are expressed by chimeric rabies viruses. This method is readily applied to the production of other antibodies, including, but not limited to, those directed against HIV or other Rhabdoviruses for example.
[0023] Antibody molecules bind to ligands with high affinity and specificity, the ability to discriminate between the epitope to which it is directed and any other epitope, makes them ideal immunotherapeutic agents. Immunotherapy includes, but is not limited to, treatment (prophylactic or post-exposure) for infectious agents, allergens, cancer, or any other condition in which an antigen is recognized.
[0024] The present invention is directed to recombinant, non-segmented, negative-stranded RNA virus vectors expressing a human antibody, the antibody is directed against any known antigen. In one embodiment of the invention the antibody is purified away from infected cells. In another embodiment of the present invention the viral vector expressing a human antibody is used. Both the purified antibody, as well as the viral vector expressing antibody, are used for prophylactic or post-exposure treatment of infectious diseases, for treatment of cancers or for any condition in which an antigen is recognized.
[0025] cDNA Cloning of Human IgG Heavy and Light Chains from JA-3.3A5 Hybridoma Cell
[0026] Total RNA was isolated from JA-3.3A5 hybridoma cell by using RNAzol B (Biotecx Laboratories, Houston). Reverse transcriptase reactions were performed at 42° C. for lhr with avian myeloblastosis virus reverse transcriptase (Promega) and oligo(dT) primer. A portion of the RT products were subjected to polymerase chain reaction (PCR) amplification using heavy chain specific primers: IgG-HF1 primer (5′-ACC ATG GAGTTTGGGCTGAG-3′ (SEQ. ID. NO: 1); start codon of heavy chain underlined, (gene bank accession # Y14737), and IgG-HR1 primer (5′-AC TCA TTTACCCGGGGACAG-3′ (SEQ. ID. NO: 2); stop codon of heavy chain underlined, (gene bank accession # Y14737) or light chain specific primers: IgG-LF5 primer (5′-AGC ATG GAAGCCCCAGCTCA-3′ (SEQ. ID. NO: 3); start codon of light chain underlined, (gene bank accession # M63438), and IgG-LR2 primer (5′-CT CTA ACACTCTCCCCTGTTG-3′ (SEQ. ID. NO: 4); stop codon of light chain underlined, (gene bank accession # M63438). Amplification was carried out for 35 cycles of denaturation at 94° C. for 60 sec, annealing at 50° C. for 60sec, and elongation at 72° C. for 90 sec with Taq DNA polymerase (Promega). The PCR products (1.4 kb for heavy chain, 0.7 kb for light chain) were purified and sequenced by using the AmpliTaq cycle sequencing kit (Perkin-Elmer) with the specific primers. The PCR products were cloned into TA cloning vector, pCR2.1 (Invitrogen). The cloned heavy chain and light chain sequence was confirmed by DNA sequencing.
[0027] Construction of Recombinant Rabies Virus Clones Containing Human IgG Heavy and Light Chains.
[0028] The human antibody that is expressed is directed against rabies virus (RV) glycoprotein, therefore a modified version of the previously described rabies virus expression vector (Schnell, et al, Proc. Natl. Acad. Instit. Sci. USA 97: 3544-3549, 2000) which contains a chimeric Vesicular Stomatitis virus (VSV)/rabies virus glycoprotein (G) is used in the present invention. This chimeric glycoprotein contains the ecto- and transmembrane domain of VSV glycoprotein fused to the cytoplasmic domain of RV glycoprotein (SPBN, FIG. 1).
[0029] IgG heavy chain cDNA was amplified by PCR using Vent polymerase (New England Biolabs) and primers IgG H BsiWI (5′-AACGTACGACC ATG GAGTTTGGGCTGAGCT-3′ (SEQ. ID. NO: 5); BsiWI site in bold face, the start codon underlined) and IgG H Nhe (5′-AAGCTAGC TCA TTTACCCGGGGACAGGGAG-3′ (SEQ. ID. NO: 6); NheI site in bold face, the stop codon underlined). For IgG light chain cDNA, IgG L BsiWI (5′-AACGTACGAGC ATG GAAGCCCCAGCTCAGC-3′ (SEQ. ID. NO: 7); BsiWI site in bold face, the start codon underlined) and IgG L Xba (5′-GGTCTAGA CTA ACACTCTCCCCTGTTGAAG-3′ (SEQ. ID. NO: 8); NheI site in bold face, the stop codon underlined) were used. PCR products were digested with BsiWI and NheI (for heavy chain cDAN), or BsiWI and XbaI (light chain cDNA), and ligated to pSPBN, which had been digested with BsiWI and NheI, or BsiWI and XbaI, respectively. The resulting plasmids were designated pSPBN-H (heavy) and pSPBN-L (light).
[0030] A recombinant RV expressing both the heavy and light chains from one viral genome was constructed. The coding region of the light chain, INT5(+), was amplified by PCR using the primers ITN5(+) (5′-CTGTCTCCGGGTAAATGAGTCA TGAAAAAAA CT AACA CCCCTAGCATGGA AGCCCCAGCTCA-3′ (SEQ. ID. NO: 9) [stop codon of the heavy chain and start codon of the light chain italicized, rabies virus transcription stop/start signal underlined] and IgG-LR2 (SEQ. ID. NO: 4). The coding region of the heavy chain was amplified by PCR using the primers INT3(−) TGAGCTGGGGCTTCCATGCTAGGGGTGTTAGTTTTTTTCATGACTCATTTA CCCGGAGACAG-3′ (SEQ. ID. NO: 10) and IgG-HF1 (SEQ. ID. NO: 1). Both PCR products were annealed, and amplified by PCR using Vent polymerase and primers IgG H Bsi (SEQ. ID. NO: 5) and IgG L Xba (SEQ. ID. NO: 8) primers. The 2.1 kb PCR product was digested with BsiWI and XbaI, and ligated to pSPBN. The resulting plasmids were designated as pSPBN−H+L.
[0031] Recovery of Recombinant Rabies Virus
[0032] Recombinant viruses free of vaccina virus were rescued as described (Finke, S. and K. K. Conzelmann, Journal of Virology, 73:3818-25, 1999; Schnell, et al, Proc. Natl. Acad. Instit. Sci. USA 97: 3544-3549, 2000). Briefly, BSR-T7 cells (Buchholz, Journal of Virology, 73:251-9, 1999) were grown overnight to 80% confluency in 6-well plates in DMEM supplemented with 10% FBS. One hour before transfection, cells were washed twice with serum-free DMEM. Cells were transfected with 5.0 μg of full-length plasmid, 5.0 μg of pTIT-N, 2.5 μg of pTIT-P, 2.5 μg of pTIT-L, and 2.0 μg of pTIT-G (Finke, S. and K. K. Conzelmann, Journal of Virology, 73:3818-25, 1999), using a CaPO 4 transfection kit (Stratagene, La Jolla, Calif.). After 2-3 h, cells were washed twice and maintained in DMEM supplemented with 10% FBS for 3 days. The culture medium was transferred onto BSR cells and incubated for 3 days at 34° C. The BSR cells were examined for presence of rescued virus by immunofluorescence assay with FITC-labeled rabies virus N protein-specific antibody.
[0033] These passages were repeated to replenished with serum-free medium supplemented with 0.2% bovine serum albumin, and incubated at 37° C.
[0034] The supernatant of positive cell cultures was infected into BSR cells, and 3-4 days later, the infected culture was passaged with 1:6 dilution. In each passage, the BSR cells were examined for presence of rescued virus by immunofluorescence. These passages were repeated to get a high yield of the virus. Rescued viruses generated from full-length plasmids; pSPBN-Heavy, pSPBN-Light, pSPBN−H+L were SPBN-Heavy, SPBN-Light, SPBN−H+L, respectively. Sequences of recombinant viruses were confirmed by sequencing of the RT-PCR fragments.
[0035] Cells and Viruses
[0036] Neuroblastoma NA cells of A/J mouse origin and murine myeloma cells (Sp2/o), were grown at 37° C. in RPMI 1640 medium supplemented with 10% heat-inactivated fetal bovine serum (FBS). Chinese hamster ovarian cells (CHO), BSR cells, a cloned cell line derived from BHK-21 cells, and BSR-T7 cells, a cell line derived from BSR cells which constitutively express T7 RNA polymerase (1), were grown at 37° C. in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% heat-inactivated FBS. Mouse-human heterohybrid cell producing human monoclonal antibody (h Mab) JA-3.3A3 were established as previously described (Champion, H J. M., et al., J. Immunol. Methods 235:81, 2000).
[0037] CVS-N2c and CVS-B2c are subclones of the mouse-adapted CVS-24 rabies virus (Morimoto et al., Proc. Nati. Acad. Sci. USA 95: 3152, 1998). SHBRV-18 and DRV-4 are street rabies virus strains associated with silver-haired bats or dogs, respectively (Dietzschold et al., J. Hum. Virol. 3:50, 2000). SN-10 is a non-pathogenic virus strain derived from SAD B 19 (Schnell et al., Proc. Natl. Acad. Sci. USA 97:3544, 1994).
[0038] Virus Infection and Virus Titration
[0039] Cells were infected with the different recombinant viruses at a m.o.i. of 1.0 and incubated for 1 hr at 37° C. Then the cells were washed twice with RPMI 1640 or DMEM, replenished with serum-free medium supplementd with 0,2% bovine serum albumin, and incubated at 37° C.
[0040] To determine the virus yield, monolayers of NA cells in 96-well plates were infected with serial 10-fold dilutions of virus suspension and incubated at 34° C. as described (Wiktor, et al., Biochem., Soc. Transactions 22: 940, 1994). At 48 hrs postinfection, cells were fixed in 80% acetone and stained with fluorescein isothiocyanate (FITC)-labeled rabies virus N protein-specific antibody (Centocor Inc. Malvern, Pa.). Foci were counted using a fluorescence microscope. All titrations were carried out in triplicate.
[0041] Virus Neutralization Test
[0042] Supernatant samples from infected cells were exposed to short wave UV light for 20 minutes to inactivate the virus and then tested for presence of virus neutralizing antibody using the rapid fluorescent inhibition test (RFFIT) as previously described (Wiktor, et al., Dev. Biol. Stand. 57: 199, 1984). The virus-neutralizing antibody (VNA) titer was normalized to international units (I.U.) using the World Health Organization (WHO) anti-rabies virus antibody standard.
[0043] Purification of Antibody by Affinity Chromatography
[0044] Recombinant human monoclonal antbody (r h Mab) was purified using a protein A column (rProtein A Sepharose™ Fast Flow, Amersham Pharmacia Biotech). Briefly, supernatants were clarified by filtration through a 0.45 μm membrane and the pH adjusted to 8.0 with 1N NaOH. Supernatant was run through the column at a linear flow rate of approximately 100 ml/hr. To destroy infectious virus and to remove viral and cellular contaminants , the column was washed with PBS containing 1% Triton X 100 followed by PBS alone, and antibody was eluted from the column using a 0.1M citric acid, pH 3.0. Two ml fractions were collected, each fraction dialyzed against PBS, and protein concentrations were determined using the protein detection assay (Bio-Rad Laboratories, Hercules Calif.) according to the manufacturer's instructions.
[0045] Polyacrylamide Gel Electrophoresis
[0046] A twenty μl aliquot from each fraction eluted from the protein sepharose column was mixed with an equal volume of loading buffer (100 mM Tris-HCl, pH 6.8, 200 mM dithiothreitol, 4% SDS, 0.2% bromophenol blue, 20% glycerol) and subjected to electrophoresis on an SDS-10% SDS polyacrylamide gel. To visualize protein bands, the gel was stained with Coomassie Brillant Blue.
[0047] Results
[0048] Antibody production in tissue cultures infected with SPBN−L SPBN−H, and SPBN−H+L
[0049] Immunofluorescence analysis using FITC-conjugated antibodies specific for human kappa chains or human IgG 1 revealed that the genes encoding Ig H chain and Ig L chain are expressed in BSR cells infected with SPBN−H and SPBN−L, respectively. BSR cells ifected with SPBN−H+L expressed both, Ig H chain and Ig L chain.
[0050] To determine whether functional antibodies are expressed by the chimeric rhabdovirus vector SPBN-SN, monolayers of mouse neuroblastoma (NA) cells, BSR cells, CHO cells and Sp2/0 cells were infected at a multiplicity of infection (m.o.i). of 1.0 with SPBN−H+L or double-infected with SPBN−H and SPBN −L, each at a multiplicity of infection of 1.0. Six days after infection, the tissue culture supernatants were harvested and exposed to shortwave UV light for 20 min to inactivate the virus and then tested for presence of virus neutralizing antibody.
[0051] Virus neutralization was performed using the fluorescent focus inhibition test and employing CVS, a highly pathogenic rabies virus, as challenge virus and neuroblastoma cells as indicator cells. The titer was normalized to international units (I.U.) using the World Health Organization (WHO) anti-rabies virus antibody standard. Table 1 shows that while no virus-neutralizing activity was detected in the supernatant of NA, BSR, CHO, or SP2/0 (murine myeloma cells) cells infected with the SPBN vector, the supernatant of NA or BSR cells infected with either SPBN−H+L or double infected with SPBN−L and SPBN−H contained rabies virus-neutralizing activity. The highest virus neutralizing titer was detected in the supernatant of BSR cells infected with SPBN−H+L. Comparison of virus neutralizing antibody (VNA) titers with virus titers indicate that the level of antibody production in SPBN-H+L-infected cells correlates with the virus titer produced by these cells.
TABLE 1 Expression of rabies virus neutralizing monoclonal antibody JA-3.A3 by the rhabdovirus-based SPBN vector Vector Vector SPBN-H SPBN-H + L SPBN-L Virus titer VNA titer Virus titer VNA titer Vector FFU/ml IU/ml FFU/ml IU/ml SPBN NA 2 × 10 6 0.36 ND 0.27 0 BSR 2 × 10 7 2.84 ND 0.36 0 CHO 1.5 × 10 4 0.15 ND ND 0 Sp 2/0 5.5 × 10 5 0.15 ND ND 0
[0052] Purification and Electrophoretic Analysis of the Antibody Expressed by SPBN−H+L
[0053] To determine whether intact antibody molecules containing both light and heavy chain are secreted into the tissue culture supernatant, 350 ml supernatant harvested from 5×10 8 SPBN−H+L-infected BSR cells 6 days after infection were subjected to chromatography on a Protein A Sepharose column. After adsorption, the column was washed with PBS and the adsorbed antibody eluted with 0.25 M citric acid, pH 3.0. Two ml fraction were collected and an aliquot (20 μl) of each fraction subjected to SDS-polyacrylamide electrophoresis. Protein bands were visualized by staining with Coomasie blue. VNA testing and polyacrylamide gel electrophoresis (FIG. 2) demonstrates that the antibody, which is eluted in a sharp peak, consists of both light and heavy chain antibody. The amount of neutralizing antibody purified from the 350 ml tissue culture supernatant was 3.3 mg or 594 IU, indicating that SPBN−H+L expresses high levels of structurally and functionally intact antibody. Replenishing of the infected cells with serum-free medium followed by incubation for another 6 days resulted in a similar amount of antibody indicating that at least 19 mg of antibody is produced by 5×10 8 cells, corresponding to 38 pg/cell /12 days.
[0054] Specificity of the Antibody Expressed by SPBN−H+L
[0055] To determine whether the recombinant antibody rJA-3.3A5 expressed by SPBN−H+L exhibits the same specificity as that of the parental mouse-human heterohybrid antibody JA-3.3A5 both antibody preparations were adjusted to the same protein concentration (0.5 mg/ml) and compared for their ability to neutralize different rabies virus strains (Table 2). While the VNA titers against SN-10 and SHBRV-18 were identical, the VNA titers of rJA-3.3A5 against CVS-N2c and DRV-4 were nine times higher as compared to the titers obtained with JA-3.3A5. On the other hand, VNA titers of rJA-3.3A5 against CVS-B2c were somewhat lower than those obtained with JA-3.3A5.
TABLE 2 Comparison of the virus-neutralizing capacity of recombinant antibody rJA-3.3A5 and parental mouse-human heterohybrid antibody JA-3.3A5 VNA titer(IU) Virus strain Antibody* CVS-B2c CVS-N2c SN-10 DRV-4 SHBRV-18 JA3.3A5 1.3 12.0 4.0 18.0 4.0 rJA3.3A5 0.4 108.0 4.0 162.0 4.0
[0056] Therapeutic and Prophylactic Methods and Compositions
[0057] The invention provides methods of treatment and prophylaxis by administration to a subject of an effective amount of a purified antibody or the viral vector expressing the antibody. The subject is preferably an animal, including but not limited to animals such as cows, pigs, chickens, etc., and is preferably a mammal, and most preferably human.
[0058] The purified antibody is administered by intravenous injection. The viral vector expressing the antibody is administered so that it becomes intracellular, (see U.S. Pat. No. 4,980,286), or by direct injection, or by use of microparticle bombardment (e.g., a gene gun; Biolistic, Dupont), or coating with lipids or cell-surface receptors or transfecting agents, or by administering it in linkage to a homeobox-like peptide which is known to enter the nucleus (Joliot et al, Proc. Natl. Acad. Sci. U.S.A. 88:1864-1868, 1999).
[0059] The amount of the purified antibody, or viral vector expressing the antibody, of the invention which is effective in the treatment of a particular disorder or condition will depend on the nature of the disorder or condition, and is determined by standard clinical techniques. In addition, in vitro assays may optionally be employed to help identify optimal dosage ranges. The precise dose to be employed in the formulation will depend on the seriousness of the disease or disorder, and is decided according to the judgment of the practitioner and each patient's circumstances. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems.
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ctgtctccgg gtaaatgagt catgaaaaaa actaacaccc ctagcatgga agccccagct 60
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tgagctgggg cttccatgct aggggtgtta gtttttttca tgactcattt acccggagac 60
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The current expression systems for the production of a specific antibody are time consuming, inadequate and costly. The present invention describes a novel recombinant expression vector using non-segmented, negative-stranded RNA virus vectors to express functional antibody. A high yield of pure antibody is obtained from this expression system and is used to neutralize the effect of an antigen. For example, antibody is used in prophylactic therapeutics, as well as in the treatment of an existing diseased condition.
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This is a divisional of application Ser. No. 08/820,120 filed Mar. 19, 1997 now U.S. Pat. No. 5,846,897.
FIELD OF INVENTION
The present invention is directed to novel metal organocomplexes as catalysts for the reaction of compounds with isocyanate and hydroxy functional groups to form urethane and/or polyurethane and the process employing such catalysts. More particularly, the present invention is directed to novel complexes of zirconium or hafnium wherein one of the ligands is a diketone with at least 7 carbons in the hydrocarbon backbone chain.
These novel catalysts are useful for the production of urethanes and polyurethanes which are important in many industrial applications, such as: coatings, foams, adhesives, sealants, and reaction injection molding (RIM) plastics.
BACKGROUND OF THE INVENTION
The reaction of isocyanate and hydroxy compounds to form urethanes is the basis for the production of polyurethanes. Metal compounds (e.g., tin, zinc and bismuth compounds) and tertiary amines have been known to catalyze the reaction of isocyanate and hydroxyl groups to form urethane. See, Proceedings of Water Borne and High Solids Coatings Symposium, Feb. 25-27, 1987, New Orleans, at Page 460. Compounds useful for the isocyanate-hydroxy reaction are also referred to as urethane catalysts. At present, the commercially available catalysts used in this reaction are organotin compounds (e.g., dibutyltin dilaurate and dibutyltin diacetate), zinc carboxylates, bismuth carboxylates, organomercury compounds and tertiary amines.
There are several problems with these commercially available catalysts. When they are used in the process for polyurethane coatings, the cure of the coatings under high humidity or at low temperature conditions is not satisfactory. They catalyze the undesirable side reaction of isocyanate with water to form amines and carbon dioxide. The carbon dioxide may cause blisters in the coating and the amines react with isocyanates resulting in low gloss coatings. Moreover, the cure rate at low temperatures is too slow. The commercially available catalysts also catalyze the degradation of the resulting polymer product. Furthermore, several of the commercially available urethane catalysts, particularly those containing heavy metals and tertiary amines, are highly toxic and are environmentally objectionable.
The testing of zirconium acetylacetonate and zirconium tetra-3-cyanopentanedionate, as catalysts for the isocyanate-hydroxy reaction have been described in GB Patents 908949, 890,280 and 869988. Subsequent testing by others, however, has shown that zirconium acetylacetonate is a poor catalyst for the urethane reaction. B. D. Nahlovsky and G. A. Zimmerman, Int. Jahrestag. Fraunhofer--Inst. Treib-Explosivst., 18th (Technol. Energ. Mater.), 39:1-12, reported that the catalytic efficiency of zirconium acetylacetonate for the isocyanate-hydrox reaction to form urethane is low. The solubility of zirconium acetylacetonate and zirconium tetra-3-cyanopentanedionate in solvents commonly used in the production of coatings is poor. Examples of such solvents include esters ketones, glycolesters and aromatic hydrocarbons, such as: butyl acetate, methyl iso-amyl ketone, 2-methoxy propylacetate, xylene and toluene. Because of the low catalytic efficiency and the poor solvent solubility, the use of these compounds as catalysts in processes involving urethane or polyurethanes have been limited.
Further testing using zirconium acetylacetonate in our laboratory has shown that zirconium compounds disclosed in the prior art, will only catalyze the isocyanate-hydroxy reaction when carried out in a closed system, i.e., in a closed pot. This is impractical for many of the polyurethane applications. The zirconium diketonates of the prior art failed as catalysts when the reaction is carried out in the open atmosphere, unless there is present a large excess of the corresponding diketone. For zirconium acetylacetonate, the presence of over 1000 to 1 mole ratio of 2,4-pentanedione to zirconium acetylacetonate is required. However, 2,4-pentanedione and other similar diketones are volatile solvents which, when used in an open vessel, pollute the air, and pose both an environmental and a fire hazard. In addition, the presence of the free diketone causes discoloration of the catalyst, resulting in an undesirable, discolored product.
The objective of this invention is to develop catalysts with high catalytic efficiency for the isocyanate-hydroxy reaction to form urethane and/or polyurethane.
A second objective of the present invention is to develop catalysts which provide improved cure at a lower temperature and is less sensitive to the presence of water.
A further objective of the present invention is to develop metal diketonates as catalysts which would not be deactivated when the reaction is exposed to the atmosphere nor require an excess of free diketone.
Another objective of the present invention is to provide catalysts for the isocyanate-hydroxy reaction which would not catalyze the undesired side reaction of water with isocyanates or the undesired degradation of the polyurethane.
SUMMARY OF THE INVENTION
This invention is directed to a catalyst for the isocyanate-hydroxy reaction having the chemical structure:
Me(X.sub.1,X.sub.2,X.sub.3,X.sub.4) (I)
wherein Me is zirconium (Zr) or hafnium (Hf) and X 1 , X 2 , X 3 , and X 4 , are the same or different and selected from the group consisting of a diketone and an alkylacetoacetate having the structures:
R.sub.1 COCH.sub.2 COR.sub.2 (II)
and
R.sub.1 OCOCH.sub.2 COR.sub.2 (III)
wherein each of R 1 and R 2 is a branched or linear C 1 -C 20 hydrocarbon and at least one of X 1 , X 2 , X 3 , and X 4 is a diketone with structure (II) wherein the total number of carbons in R 1 +R 2 is at least 4. That is, the number of carbons in the backbone of the hydrocarbon chain is at least 7. The preferred diketones are those containing a total number of carbons in R 1 +R 2 of at least 5, i.e. the number of carbons in the hydrocarbon backbone is at least 8. Also preferred are metal complexes wherein all of the ligands, X 1 , X 2 , X 3 , and X 4 are diketones with structure (II).
The catalyst may also be a mixture of zirconium or hafnium diketonates as defined above or a mixture of a diketonate and an alkylacetoacetate of zirconium or hafnium, with at least one of the the compounds in the mixture being a zirconium or hafnium diketonate complex wherein one of the four ligands in the complex is a diketone having at least 7 carbons in the hydrocarbon backbone of the molecule.
The catalyst may also be a blend of zirconium or hafnium pentaedionate or acetylacetonate with a diketone having at least 7 carbons in the hydrocarbon backbone of the molecule. This is because the ligands of the zirconium or hafnium complex readily exchange with the diketone of structure (II) to form the catalyst in situ.
DETAILED DESCRIPTION OF THE INVENTION
The catalyst for an isocyanate-hydroxy reaction to produce urethane or polyurethane comprise a metal organocomplex with the chemical structure:
Me(X.sub.1,X.sub.2,X.sub.3,X.sub.4) (I)
wherein Me is zirconium (Zr) or hafnium (Hf) and X 1 , X 2 , X 3 , and X 4 , are the same or different selected from the group consisting of a diketone and an alkylacetoacetate having the structures:
R.sub.1 COCH.sub.2 COR.sub.2 (II)
and
R.sub.1 OCOCH.sub.2 COR.sub.2 (III)
wherein each of R 1 and R 2 is a branched or linear C 1 -C 20 hydrocarbon and at least one of X 1 , X 2 , X 3 , and X 4 is a diketone with structure (II) wherein the total number of carbons in R 1 +R 2 is at least 4. That is, the number of carbons in the backbone of the diketone is at least 7. The preferred diketones are those wherein the total number of carbons in R 1 +R 2 is at least 5, i.e., with at least 8 carbons in the backbone of the molecule. Also preferred are metal complexes wherein all of the ligands, X 1 , X 2 , X 3 , and X 4 are diketonates.
The catalyst may also be a mixture of zirconium or hafnium diketonates or a mixture of diketonate and alkylacetoacetate of zirconium or hafnium, with at least one of the the compounds in the mixture being a zirconium or hafnium diketonate complex wherein one of the four ligands in the complex has at least 7 carbons in the hydrocarbon backbone.
The catalyst may also be a blend of zirconium or hafnium pentanedionate or acetylacetonate with a diketone having at least 7 carbons in the hydrocarbon backbone of the molecule.
The metal complexes of this invention can be synthesized via the known ligand exchange reactions of zirconium or hafnium compounds with the desired diketone. These reactions are described by R. C. Fay in the chapter on zirconium and hafnium, in Geoffrey Wikinson ed., Comprehensive Coordination Chemistry, Vol.3, page 363, Pergamon Press, (1987).
The metal complexes with mixed ligands can be prepared by charging the starting zirconium compound into a solution containing the desired ligand(s) at specified mole ratios. The ligand exchange reaction is facile and can be accomplished by blending the starting zirconium or hafnium compound and the desired ligand as a chelating agent at an ambient or slightly elevated temperature. This blending can be carried out in a solvent such as a polyol, e.g. propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,6-hexane diol, polypropylene glycol (MW 400-2600), polytetramethylene glycol (MW 200-1000), dimethoxy-dipropylene glycol or other diluents, such as xylene, methyl iso-amyl ketone, dibutylether, butoxy/propoxy/ethoxy polypropylene ethylene glycol ether.
Typical starting zirconium or hafnium compounds include the chloride, oxychloride, alkoxide, carbonate, and acetylacetonate of zirconium or hafnium. Typical ligands or chelating agents of Structure II include: 6-methyl-2,4-heptanedione (wherein R 1 =C1 and R 2 =C4), 2,2,6,6-tetramethyl-3,5-heptanedione (wherein R 1 =C4 and R 2 =C4), n-valerylacetone (wherein R 1 =C1 and R 2 =C4), n-hexanoylacetone (wherein R 1 =C1 and R 2 =C5), n-octanoylacetone (wherein R 1 =C1 and R 2 =C7), n-nonanoylacetone(R1=C1, R2=C8), n-decanoylacetone (wherein R 1 =C1 and R 2 =C11) and the like.
The isocyanates useful in this invention are aliphatic, aromatic isocyanates or polyisocyanates or resins with terminal isocyanate groups. The resins may be monomeric or polymeric isocyanates. Typical monomeric isocyanates include: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), phenyl isocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate(IPDI), meta-tetramethylxylene diisocyanate (TMXDI), nonanetriisocyanate (TTI) or vinyl isocyanate, or the like. The above monomeric isocyanates are those which are more commonly used and is not meant to be exclusive. The polymeric polyisocyanates useful in the invention are isocyanurate, allophanate, or biuret compounds and polyurethane products derived from the monomeric diisocyanates as listed hereinablove. Also useful are addition products of monomeric isocyanates with polyester and polyether polyols containing terminal isocyanate groups.
The polyols or resins with hydroxy functional groups useful in this invention comprise monomeric compounds or polymeric compositions containing at least two hydroxy groups per molecule. The molecular weight of the hydroxy containing compounds useful in this invention ranges from 62 to 1,000,000; the preferred range for polyols being between 300 to 2000 when used in solvent borne high solids coatings. Typically, the hydroxyl number of the hydroxy containing resin can be from 10-1000. Optionally, the polyol may contain other functional groups such as carboxyl, amino, urea, carbamate, amide and epoxy groups. The polyol, a blend of polyols or a combination of polymeric polyols and monomeric diols may be employed in a solvent free system, or as a solution in an organic solvent, or as a dispersion/emulsion in water. Typical examples include: polyether polyol, polyester polyol, acrylic polyol, alkyd resin, polyurethane polyol, and the like.
The polyether polyols are the reaction products of ethylene or propylene oxide or tetrahydrofuran with diols or polyols. Polyethers derived from natural products such as cellulose and synthetic epoxy resins may also be used in this invention. Typical polyester polyols are prepared by the reaction of diols, triols or other polyols with di- or polybasic acids. Alkyds with hydroxy functional groups are prepared in a similar process except that mono functional fatty acids may be included. Acrylic polyols are the polymerization products of an ester of acrylic or methacrylic acid with hydroxy containing monomers such as hydroxyethyl, hydroxypropyl or hydroxybutyl ester of acrylic or methacrylic acid. These acrylic polymers can also contain other vinyl monomers such as styrene, acrylonitrile vinyl chloride and others. In addition, polyurethane polyols are also useful in this invention. These are the reaction products of polyether or polyester polyols with diisocyanates.
The polyols listed above are illustrative and are not meant to limit the scope of the invention.
Typically the polyols are either synthesized in bulk in the absence of a solvent or are prepared in the presence of a diluent or by emulsion polymerization in water. Alternatively, they may be prepared in bulk or in a solvent and then dispersed in water. For a description of the methods of preparing polyols see Organic Coatings Science Technology, vol. 1, Wiley-Interscience Co., 1992.
The concentration of the catalysts used is generally from 0.000 wt % to 5 wt % on total resin solids. Typically, the concentration of catalysts used is between 0.001 to 0.1 wt % based on the total amount of polyol and polyisocyanate, also known as binders. The catalyst concentration used is generally a compromise between pot-life of the formulation and the required cure rate.
The catalyst of the present invention is particularly suitable for applications where exceptionally fast cure is required. For example, the catalysts of the present invention is particularly useful in plural component spray gun applications wherein the catalyst is added to one of the components and the polyol and the isocyanate is mixed in situ in the spray gun. These are important in applications for roof or floor coatings, where the person applying the coating would be able to walk on the freshly applied coating a few minutes after the coating has been applied. Good cure rate is also required for coatings applied at a low temperature or in the presence of moisture, conditions where the catalyst of this invention excels.
Reactive injection molding (RIM) is another area where fast cure is essential. The reactants and catalyst are injected concurrently into a mold, and mixing is achieved during injection. In this application, fast reaction is essential to permit a short cycle time.
The ratio of NCO/OH in the formulation is in the range of 0.1-10.0 to 1, preferably 0.5-2.0 to 1 depending upon the end use. For a typical high solids application, the preferred isocyanate to hydroxy ratio is usually 1.0:1 to 1.1:1. For many water-borne applications, an excess of isocyanate is required. Typically the ratio for such applications is 1.5:1 to 2.0:1.
The catalyst formulation can be solvent borne, high solids, 100% solids or dispersable in water. Other additives which may be utilized in the formulation to impart desired properties for specific end uses. For example, 2,4-pentanedione, can be used together with the catalyst to extend pot life.
For most isocyanate crosslinked coatings, solvents which are free of hydroxy groups and water are used. Typical solvents are esters, ketones, ethers and aliphatic or aromatic hydrocarbons.
The catalytic efficiency of the metal complexes of this invention is determined by measuring the drying time of the coated film or by a gel test. For drying time measurement, the liquid formulation containing polyisocyanate, polyol and catalyst was cast on a metal panel and the surface dry time and the through dry time were recorded with a circular Gardner Drying Time Recorder. For the gel test, liquid polyisocyanate, liquid polyol solution and catalyst were mixed thoroughly at room temperature. The time needed from mixing the liquid components to forming a gel (the time interval when the liquid formulation becomes non-flowable) was recorded as gel time.
The catalysts of this invention exhibit excellent catalytic efficiency, measured as drying time of the coated film and/or gel time, for the isocyanate-hydroxy reaction compared to zirconium diketonates reported in prior art and commercially available organotin catalysts, especially at low temperatures. For example, in a coating formulation with polyisocyanate and acrylic polyol, the cure rate of a formulation with zirconium tetra 6-methyl-2,4-heptanedionate as a catalyst is more than 5 times faster than the formulation with commercial dibutyltin dilaurate at the same metal concentration.
This is surprising. Zirconium tetraacetylacetonate described in the prior art (wherein X 1 ═X 2 ═X 3 ═X 4 and R 1 ═R 2 ═CH 3 ), does not function as an effective curing catalyst. Even though the gel time is shorter than the uncatalyzed process, it is still too long. Further, exposure to atmosphere deactivates zirconium tetraacetylacetonate. However, when one of the ligands in zirconium tetraacetylacetonate is replaced with a diketonate with at least 7 carbons in the backbone, or when zirconium tetraacetylacetonate is in a mixture with a metal complex of the present invention, or when zirconium tetraacetylacetonate in mixed with a diketone with at least 7 carbons in the hydrocarbon backbone, an effective catalyst is obtained.
The catalyst of this invention also preferentially catalyze the isocyanate-hydroxy reaction over the isocyanate-water reaction. Organo tin does not exhibit this preferential catalysis, and also catalyze the isocyanate-water reaction, which leads to the formation of carbon dioxide and gassing. For example, to prepare a polyurethane coating with exclusive carbamate linkages, a coating formulation containing HDI based aliphatic isocyanate and a polyurethane diol with beta-carbamate was formulated. When the metal complex of the present invention was used as the catalysts, a hard glossy film was obtained. Whereas, with dibutyltin dilaurate as the catalyst, a hazy film was obtained. This is due to the competing reaction of isocyanate with moisture in the air.
Furthermore, it is known that commercial organotin urethane catalysts will affect the durability of the final product. This is due to the catalytic effect of organotin catalysts on the degradation of the polymer product. The metal complexes of the present invention shows less of a catalytic effect on the degradation of the polymer than the tin urethane catalysts. For a solution with polyester resin, water and catalysts, the degradation rate of polyester with the catalyst of this invention is 5 times slower than a typical tin catalyst.
To avoid pigment adsorption or interference from other components which may deactivate the catalyst, it would be an advantage if the catalysts can be pre-blended with the isocyanate component in a two component system. However, a number of urethane catalysts also catalyze the dimerization or trimerization reactions of isocyanate and cannot be pre-blended with the isocyanate component. A solution of a polyisocyanate with the catalysts of this invention showed good compatibility and stability.
The following examples are provided to illustrate the present invention and are not meant to limit the scope thereof.
EXAMPLE 1
Catalyst Evaluation
A liquid coating formulation containing polyisocyanate, polyol and the catalyst as shown in Table 1 was prepared. The formulation was applied to an iron phosphate treated cold roll steel (Bo 1000) panel via a draw down bar to provide a wet film thickness of 1.7 mils. The panels were allowed to cure at room temperature and at 5° at a relative humidity of 50-60%. The cure rate for formulations wherein zirconium complexes were used as the catalyst is presented in Table IIA. This can be compared with the formulation wherein dibutyltin dilaurate was used as the catalyst shown in Table IIB. The drying time of the coated film was recorded using a Gardner Circular Drying Time Recorder with a Teflon stylus. The Teflon stylus moves at a constant speed on the top of the film after the film was applied. The time between applying the film and when the Teflon stylus no longer leaves a clear channel, but begins to rupture the drying film is recorded as surface dry time. The time between applying the film and when the stylus no longer ruptures or dents the film is recorded as through dry time. The time between mixing isocyanate and polyol solutions and the moment that the liquid becomes a non-flowable gel is recorded as gel time. The solubility of each catalyst in the formulation was noted. The results presented in Tables IIA & IIB showed that the catalysts of this invention provided much improved catalytic efficiency and are more soluble in the solvent, methyl amyl ketone, than the catalysts of the prior art.
TABLE I______________________________________Polyurethane Formulation used In Cure Rate TestMaterial Parts by Weight______________________________________Part A:Acrylic polyol solution.sup.a 58.8Methyl amyl ketone 24.8(solvent)Part B:Aliphatic polyisocyanate.sup.b 16.4Metal catalyst as wt % metal 0.0046based on total resin solidsFormulation parametersTotal resin solids by weight 58.7%NCO/OH ratio 1.2______________________________________ .sup.a Joncryl SCX 906 Acrylic polyol: 72 wt % in methyl amyl ketone with a hydroxy equivalent weight on solids of 600 (SC Johnson Polymer, Racine WI). .sup.b Desmodur N3300 Polyisocyanate (isocyanurate of hexamethylene diisocyanate), 100% solids, NCOequivalent weight of 194 (Bayer Corporation, Pittsburgh, PA).
TABLE IIA__________________________________________________________________________Cure Rate of Zirconium Complexes(Room Temperature: 22-25° C.) Wt % Me Surface ThroughZr Catalyst dry time dry time Solubility in(moles of chelating agent) complex MIN MIN Formulation__________________________________________________________________________TMHD (4) 11.1 20 40 120 goodMHD (4) 10 13.9 excellentMHD (2) & ACAC (2) 206.0 goodDMHFOD (4) 240 7.2 240-300 goodMHD (2) & DMHFOD (2) 25 excellentMHD (3) butanol (1) 60.5 300 excellentMHD (2) & 120-180 14.4 150 360 excellentethylacetoacetate (2)MHD (3) & ACP (1) 2514.0 goodDBM (2) & MHD (2) 2011.1 goodZr acac/MHD (1:1 by weight)* 15 good__________________________________________________________________________
TABLE IIB__________________________________________________________________________Comparative Examples Wt % Me Surface Through dryZr Catalyst dry time time solubility in the(moles of chelating agent) complex MIN MIN formulation__________________________________________________________________________ ACAC (4) 18.7 90 >720 >1440 poorZr Butoxide >720 23.8 >720 >720 goodEthylacetoacetate (4) >720 >720 >720 goodcyclopetadiene (2) & >720 >720 >720 goodchloride (2)DBM (4) 1809.3 poor3-Ethyl-acetylacetone (4) 15.2 >720 >720 >720 poor1,1,1-trifloro- >720 >720 pooracetylacetone (4)DBM (2) BAC (2) 180 poorBAC (4) >720 12.4 >720 >720 poorTriacetyl methane (4) >720 >720 goodDibutyltin dilaurate 180-240 excellentno catalyst >720 -- >720 >720__________________________________________________________________________ Key for Tables IIA & IIB: ACAC: 2,4Pentanedione ACP: 2acetocyclopetanone BAC: Benzoylacetone DBM: dibenzoylmethane DMHFOD: 2,2dimethyl-6,6,7,7,8,8-heptafluoro-3,5-octanedione MHD: 6methyl-2,4-heptanedione TMHD: 2,2,6,6tetra-methyl-3,5-heptanedione *Blend of zirconium acetylacetonate with 6methyl-2,4-heptanedione
EXAMPLE 2
Catalyst Efficiency
The cure rate of zirconium tetra 6-methyl-2,4-heptane-dionate was compared with dibutyltin dilaurate in an aromatic polyisocyanate and polyether polyol system. In this experiment, polyisocyanate, polyether polyol and the metal catalyst were mixed thoroughly. The time from mixing to the formation of gel, i.e., when the liquid formulation became non-flowable, was recorded as gel time. The results in Table 3 showed that the catalytic efficiency of the catalysts of this invention is significantly higher than that of the commercially available tin catalyst.
TABLE III______________________________________Comparison of Gel Time For Reactionof Aromatic Polyisocyanate and Polyether PolyolFormulation parameters:NCO/OH = 1.040.01% metal on total resin solidsGel time Comparison (Room temperature, 22-25° C.)polyether polyol Zr(MHD).sub.4.sup.a DBTDL.sup.b NO CATALYST______________________________________Polypropylene glycol 50 min >8 hours 10-20 hoursPPG-425OH eq wt 224.4Polypropylene glycol 150 min 4 hours >48 hoursPPG-1025OH eq wt 522.34Polyethylene glycol 400 4 min 3 hours >4 hoursOH eq wt 200______________________________________ .sup.a Zr(MHD).sub.4 = Zirconium tetra6-methyl-2,4-heptanedione .sup.b DBTDL = dibutyltin dilaurate Aromatic polymeric isocyanate based on diphenylmethane 4,4diisocyanate, 100% solids, 130 equivalent weight (Bayer Corporation, Pittsburgh, PA). Polypropylene glycol (Arco Chemical Company, Newtown Square, PA). Polyethylene glycol, Union Carbide Corporation, 39 Old Ridgebury Road, Danbury, CT 068170001.
EXAMPLE 3
Efficiency of Catalyst for the Reaction of Aliphatic Isocyanate and Polyurethane Diol
In this experiment, aliphatic polyisocyanate was reacted with a polyurethanediol (bis β-hydroxypropyl carbamate) in the presence of catalysts. The appearance of each of the resulting coating film was noted. The coating film cured with dibutyltin dilaurate appeared hazy. It is believed that the haziness resulted from the reaction of isocyanate with moisture. On the other hand, the coating film cured with zirconium tetra 6-methyl-2,4-heptanedionate (Zr(MHD) 4 ) is clear and glossy.
TABLE IV______________________________________Comparison of Film PropertiesFormulation: NCO/OH = 1.0, total resin solids by weight: 80%Material Parts by Weight______________________________________Part A:Urethanediol.sup.a 36.1Methyl ethyl ketone 15.2solventPart B:Polyiscoyanurate.sup.b 48.7Metal catalyst* varied______________________________________ *Catalyst was added at a concentration of 0.01 wt % metal on total resin solids. .sup.a KFlex UD320-100 Polyurethanediol: 100% solids, hydroxy number: 350 (King Industries, Norwalk, CT). .sup.b Desmodur N3390 Polyisocyanate based on isocyanurate of hexamethylene diisocyanate, 90% in butyl acetate, 216 equivalent weight. Bayer Corporation, 100 Bayer Road, Pittsburgh, PA 152059741.
Cure Rate and Film Properties (Room temperature)
______________________________________Catalyst Zr(MHD).sub.4 DBTDL*______________________________________Surface dry 2 hours 24 hoursGloss60° 95 2520° 75 9______________________________________ Zr(MHD).sub.4 = Zirconium tetra6-methyl-2,4-heptanedione, *DBTDL = dibutyltin dilaurate *Comparative example
EXAMPLE 4
Effect of Catalyst on the Degradation of Polymer
It is a known that polyester-urethane resins lose strength on exposure to water and is a problem. The potential for increased degradation of resins containing polyester groups in the presence of a catalyst has been of concern. The degradation is due to the hydrolysis of polyesters groups in the polymer to form carboxyl groups. The degradation can be monitored by determining the change in acid number of the resin composition.
To test the catalytic effect on the degradation of polyester containing resins, formulations were prepared wherein each catalyst was mixed together with a polyester polyol, water, and methyl ethyl ketone and maintained at 50° C. Periodically, alliquots were withdrawn and the acid number of each formulation was monitored by titration. A higher acid number indicates a higher degree of degradation.
The results of using Zirconium tetra-6-methylheptanedione, dibutyltin diacetate and no catalyst are shown in Table V. The results illustrate an advantage of the catalysts of this invention. These catalysts showed no effect on the degradation of polyester polyol as compared to the uncatalyzed formulation. Whereas, the formulation with the organotin catalyst showed marked degradation of the polyester polyol.
TABLE V______________________________________Change in Acid Number of a Polyester/H2O/CatalystMixture vs. aged time______________________________________Formulation: Methyl ethyl ketone 31.55% Polyester polyol* 59.20% water 9.25% catalyst 0.01% metal on total resin solids______________________________________ (TRS)catalyst t = 0 2 weeks 4 weeks 8 weeks 13 weeks______________________________________Zr(MHD).sub.4.sup.a 0.63 0.74 0.94 1.25 1.96DBTDAc.sup.b 2.78 3.97 6.56 9.85Control.sup.c 0.71 0.94 1.49 2.30______________________________________ .sup.a Zr(MHD).sub.4 = Zirconium tetra6-methyl-2,4-heptanedione .sup.b DBTDAc = dibutyltin diacetate .sup.c Contro1 = no catalyst *KFLEX 188 Polyester resin, 100% solids, OH number: 230, acid number: <1. (King Industries, Norwalk, CT)
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The present invention is directed to novel metal organocomplexes as catalysts for the reaction of compounds with isocyanate and hydroxy functional groups to form urethane and/or polyurethane and the process employing such catalysts. More particularly, the present invention is directed to novel complexes of zirconium or hafnium with diketones or alkylacetoacetoates. These novel catalysts are useful for the production of urethanes and polyurethanes which are important in many industrial applications, such as: coatings, foams, adhesives, sealants, and reaction injection molding (RIM) plastics.
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FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to three-dimensional cameras and, more particularly, to systems for accurately determining the distance to various objects and portions of objects in the scene.
Various techniques are known for creating a three-dimensional image of a scene, i.e., a two-dimensional image which, in addition to indicating the lateral extent of objects in the scene, further indicates the relative or absolute distance of the objects, or portions thereof, from some reference point, such as the location of the camera.
At least three basic techniques are commonly used to create such images. In one technique, a laser or similar source of radiation is used to send a pulse to a particular point in the scene. The reflected pulse is detected and the time of flight of the pulse, divided by two, is used to estimate the distance of the point. To obtain the distance of various points in the scene, the source is made to scan the scene, sending a series of pulses to successive points of the scene.
In yet another technique, a phase shift, rather than time of flight, is measured and used to estimate distances. Here, too, the entire scene or relevant portions thereof must be scanned one point at a time.
In a third technique, which also involves scanning, at least a single radiation source and corresponding detector are used, with suitable optics which act on the light in a manner which depends on the distance to the object being examined, to determine the distance to a particular point in the scene using a triangulation technique.
The major disadvantage of all three of the above-described techniques is that each requires point by point or line by line scanning to determine the distance of the various objects in the scene. Such scanning significantly increases the frame time of the system, requires expensive scanning equipment and necessitates the use of fast and powerful computational means and complex programming.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method and system for rapidly and easily determining the distance of various points in a scene without the need for scanning and complex computational capabilities.
SUMMARY OF THE INVENTION
According to the present invention there is provided a telecentric system for creating an image indicating distances to various objects in a scene, comprising: (a) a source of radiation for directing source radiation at the scene; (b) a detector for detecting the intensity of radiation reflected from the objects in the scene; (c) a source modulator for modulating the source of radiation; (d) means for collimating a portion of the radiation reflected from the objects in the scene; (e) a reflected radiation modulator for modulating the collimated radiation reflected from the objects in the scene, the reflected radiation modulator being selected from the group consisting of acousto-optical devices and electro-optical devices; (f) a source modulator control mechanism for controlling the source modulator; and (g) a reflected radiation modulator control mechanism for controlling the detector modulator.
According to a preferred embodiment of the present invention, the source modulator control mechanism and the detector modulator control mechanism operate to simultaneously control the source modulator and the detector modulator.
According to further features in preferred embodiments of the invention described below, the modulator of the source radiation and the modulator of the reflected radiation serve to alternately block and unblock or alternately activate and deactivate the source radiation and reflected radiation, respectively.
According to still further features in the described preferred embodiments the source of radiation is a source of visible light, such as a laser and the detector includes photographic film, or a video camera sensor, such as a Charge Coupled Device (CCD.)
According to yet further features, the method further includes processing the intensity of radiation reflected from the objects in the scene to determine distances of the objects and, in a most preferred embodiment, comparing the intensities detected during a relatively continuous irradiation and detector period with intensities detected during modulation of the source and the detector.
Also according to the present invention there is provided a method for creating an image indicating distances to various objects in a scene, comprising: (a) directing source radiation at the scene using a radiation source; (b) detecting intensity of radiation reflected from the objects in the scene; (c) modulating the radiation source using a radiation source modulator; (d) collimating a portion of the radiation reflected from the objects in the scene; (e) modulating the collimated radiation reflected from the objects in the scene, the modulating of the reflected radiation being effected by a modulating device selected from the group consisting of acousto-optical devices and electro-optical devices; (f) controlling the source modulator; and (g) controlling the detector modulator.
According to further features the method further includes processing the intensity of the radiation reflected from the objects in the scene to determine distances of the objects.
In a preferred embodiment, the processing includes comparison of intensities detected during a relatively continuous irradiation and detector period with intensities detected during modulation of the source and the detector.
The present invention successfully addresses the shortcomings of the presently known configurations by providing a system and method for quickly and readily determining distances to portions of a scene without the need for expensive and time consuming scanning of the scene.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1A shows one possible configuration of a system and method according to the present invention;
FIG. 1B depicts a second possible configuration of a system and method according to the present invention;
FIG. 2 shows a typical modulation scheme which might be employed in a system and method of the present invention;
FIG. 3 shows another modulation scheme which might be employed;
FIG. 4 illustrates yet another modulation scheme which can be used to enhance the accuracy of a system and method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is of a system and method which can be used to determine the distance of various portions of a scene, especially a scene which is relatively near.
The principles and operation of a system and method according to the present invention may be better understood with reference to the drawings and the accompanying description.
Referring now to the drawings, FIGS. 1A and 1B illustrates two illustrative configurations of systems according to the present invention.
With reference to the system of FIG. 1A, a source of radiation 10 directs radiation at the scene 11 being observed. For purposes of illustration, the scene depicted includes a three-dimensional object with reference being made herein to portions of the object which are relatively far and near, denoted `A` and `B`, respectively. The radiation used may be any suitable radiation having a suitable wavelength for the distances examined and other suitable properties as will become more clear from the subsequent discussion. For most applications the radiation is visible or infrared radiation, such as laser radiation or stroboscopic light.
The system further includes a detector 12 for detecting the intensity of radiation reflected from the objects in the scene. The detected radiation is that portion of the source radiation which impinges upon the object or objects of the scene and which is reflected back toward detector 12. The detector used may be any suitable detector with a suitable resolution and suitable number of gray levels including, but not limited to, a photographic film camera, electronic camera and a video camera, such as a CCD camera.
The system includes a radiation source modulator, depicted schematically as item 16, for modulating radiation source 10 or the source radiation. The system further includes a detector modulator 18 for modulating the reflected radiation which is headed for detector 12.
The word `modulate` as used herein is intended to include any varying of the level of operation or any operating parameters of radiation source 10 or of the source radiation itself and/or of the reflected radiation, as appropriate, including, but not limited to, the alternate blocking and unblocking and the alternate activating and deactivating of radiation source 10 or the source radiation and detector 12 or the reflected radiation.
Various mechanisms may be used to modulate radiation source 10 or the source radiation and the reflected radiation. For example, the source radiation may be physically blocked periodically using a suitable shutter 17 or similar element.
Other mechanisms which may be used to modulate radiation source 10 include various high frequency electronic modulation means for periodically deactivating radiation source 10/and or detector 12. Depicted in FIG. 1 is a source modulator 16 which is intended to convey the concept of electronically activating and deactivating radiation source 10.
Various means for modulating detector 12 may be envisioned, including those analogous to the means for modulating radiation source 10 described above. Preferably, the reflected radiation is modulated with the help of various electro-optical modulators, such as, for example, KDP (KH 2 PO 4 ) or any other electro-optical crystal capable of modulating or switching light, lithium niobate and liquid crystals, having fast and accurate modulation capabilities or, preferably, gating, capabilities.
It is to be noted that whenever reference is made in the specification and claims to a radiation source modulator or to the modulation of the radiation source it is to be understood as involving the modulation of the radiation source itself and/or of the source radiation.
A system according to the present invention includes a miniature iris 40 through which some of the radiation reflected from object 11 can pass. Radiation passing through iris 40 is then collimated using at least one collimating object lens 42. Iris 40 is located substantially at the focal point of collimating object lens 42.
The collimated radiation then passes through a suitable acousto-optical device or an electro optical crystal, such as KDP 18 which serves as a modulation or gating device.
The modulated radiation exiting KDP 18 passes through at least one image lens 44 which sends the modulated radiation through an exit iris 46 placed substantially at the focal point of image lens 44. Radiation passing through exit iris 46 then impinges a suitable detector, such as a CCD sensor 12.
Finally, a system according to the present invention includes mechanisms for controlling source modulator 16 and detector modulator 18. Preferably, the mechanisms for controlling source modulator 16 and detector modulator 18 operate together in a coordinated manner, or, most preferably, are the same mechanism 20, so as to simultaneously control source modulator 16 and detector modulator 18.
The simultaneous control may be synchronous so that the operation of both radiation source 10 and detector 12 is affected in the same way at the same time, i.e., synchronously. However, the simultaneous control is not limited to such synchronous control and a wide variety of other controls are possible. For example, and without in any way limiting the scope of the present invention, in the case of blocking and unblocking control, radiation source 10 and detector 12 may be open for different durations during each cycle and/or the unblocking of detector 12 may lag the unblocking of radiation source 10 during each cycle.
A system according to the present invention further includes a suitable processor 22 which analyzes the intensity of radiation detected by detector 12 and determines the distances to various objects and portions of objects in the scene being examined. The operation of processor 22 is explained in more detail below.
A variation of a system according to the present invention is depicted in FIG. 1B. The configuration of FIG. 1B differs from that of FIG. 1A in a number of respects, the principal of these being that in FIG. 1B the modulation of both the source and reflected radiation is effected by KDP 18. This feature of the configuration of FIG. 1B dictates a number of changes in the configuration of the system. Thus, radiation source 10 is now input from the side into KDP 18. A beam splitter 50 is used to deflect a significant portion of the source radiation toward objects 11 and makes it possible for reflected radiation coming from objects 11 to pass through KDP 18 on its way to CCD sensor 12. The mechanism 20' which controls the modulation of KDP 18, is modified in that only a single device needs to be modulated instead of the synchronous control of two separate devices as in the configuration of FIG. 1A.
In operation, a typical system according to the present invention, using a laser as the radiation source, a CCD sensor as the detector and modulating the source and detector by synchronous switching, would operate as follows. Radiation source (e.g., laser) 10 or the source radiation is modulated. KDP 18 modulates the reflected radiation passing through it in a manner which is synchronous with the modulation of the source radiation. In the configuration of FIG. 1B KDP 18 modulates both the source radiation and the reflected radiation.
This is schematically depicted in FIG. 2 which shows a type of square wave modulation, the legend `CCD` intending to indicate the modulation of the reflected radiation as it goes through KDP 18. Thus during each cycle, both laser 10 and reflected radiation are active for a time `a` and are inactive for a time `b`. The times `a` and `b` may be the same or different. The wavelength of laser 10 and the time `a` are selected so that light from laser 10 will be able to travel to the most distant objects of interest in the scene and be reflected back to CCD 12.
The selection of the time `a` can be illustrated with a simple example. Let us assume that the scene to be examined is as in FIG. 1A and 1B with the maximum distance to be investigated being approximately 50 meters from the source or detector, i.e., both objects A and B are within about 50 meters from the detector and source. Light traveling from the source to the farthest object and back to the detector would take approximately 0.33 μsec to travel the 100 meters. Thus, the time duration `a` should be approximately 0.33 μsec.
Systems and methods according to the present invention are based on the idea that a near object will reflect light to the detector for a longer period of time during each cycle than a far object. The difference in duration of the detected reflected light during each cycle will translate to a different intensity, or gray level, on the detector. Thus, for example, if we assume that a certain point on object B is a certain number of meters away from the source and/or detector while a certain point on object A is a greater distance away, then reflected light from the point on B will start arriving at the detector relatively early in the active portion of the detector cycle (see FIG. 2) and will continue to be received by the detector until the detector is deactivated at the end of the active portion of the detector cycle. The reflected light from the point on B will continue to proceed toward the detector for a period `a` which corresponds to the period of irradiation (see the dot-dash-dot line in FIG. 2). However, the portion of this reflected radiation which falls beyond the deactivation or blocking of the detector will not be received by the detector and will not contribute toward the intensity sensed by the corresponding pixels of the detector.
By contrast, light reflected from the point on object A will start arriving at the detector later during the active portion of the detector cycle and will also continue to be received by the detector until the detector is deactivated.
The result is that reflected light from a point on object B will have been received for a longer period of time than reflected light from a point on object A (see the shaded areas in FIG. 2). The detector is such that the intensity of gray level of each pixel during each cycle is related to the amount of time in each cycle during which radiation was received by that pixel. Hence, the intensity, or gray level, can be translated to the distance, relative or absolute, of the point on the object.
As stated above, the synchronous on/off operation described in the example and depicted in FIG. 2, is not the only the only possible mode of operation. Other modulations may be used. For example, the radiation source and/or detector may be modulated harmonically as shown in FIG. 3.
To avoid obtaining false signals from distant objects which are beyond the region of interest, it may be desirable to increase the time duration `b` during which the source/detector are inactive so that the bulk of the reflected radiation from faraway objects which are of no interest reaches the detector when the detector is deactivated and therefore do not contribute to the intensity detected by the corresponding pixel of the detector. A proper choice of the duration `b` thus can be used to ensure that only reflected radiation from objects within the desired examination range are received during each specific cycle, thereby facilitating the interpretation of the intensity image.
As will readily be appreciated, in certain applications, different portions of the various objects in the scene may have different reflectivities. The different reflectivities result from different colors, textures, and angles of the various portions of the objects. Thus, two points which are the same distance from the source/detector will be detected as having different intensities which could lead to false distance readings which are based on intensities, as described above.
It is possible to readily compensate for differences in reflectivities of different objects or portions of objects being examined. As is well known, the intensity detected by a pixel of a detector receiving continuous radiation from a specific portion of a scene is directly proportional to the reflectivity of the portion of the scene being viewed and inversely proportional to the square of the distance between the portion of the scene being viewed and the detector.
It can readily be shown that when a pulsed radiation source, such as those described above, is used the intensity detected by a pixel of a detector receiving radiation from a specific portion of a scene is still directly proportional to the reflectivity of the portion of the scene being viewed but is inversely proportional to the distance between the portion of the scene being viewed and the detector raised to the third power.
Thus, to compensate for the effects of different reflectivities, one can use both continuous radiation and pulsed radiation. An example of such a cycle is shown in FIG. 4. Here the radiation source and detector are active for a relatively long period of time to provide the continuous intensity of the objects in the scene. Periodically, the source and detector are deactivated and the source and detector are pulsed, in the same way as described above with reference to the basic embodiment, using one or more, preferably a train, of pulses.
The detection during the pulsing portion of the cycle is used as described above. However, in addition, the continuous detection during the long active period of the cycle is used to correct, or normalize, the distances and compensate for differences in reflectivities. The compensation can be accomplished by any convenient method, for example, by dividing the intensity of each pixel during the continuous period by the intensity of the same pixel during the pulsed period, with the quotient between the two being directly proportional to the distance of the region being viewed by the pixel.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
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Apparatus for creating an image indicating distances to objects in a scene. The invention is comprised of a radiation source and modulator, telecentric optics for receiving and collimating the radiation reflected from the scene, a detector and a processor. The detector receives the collimated, reflected radiation and sends a signal to the processor. The processor forms an image having an intensity value distribution indicative of the distance of objects form the apparatus.
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FIELD OF THE INVENTION
The present invention relates generally to the cleaning of a spinning station of an open-end spinning frame, and more particularly to a method of cleaning open-end spinning stations of the type wherein the sliver is fed to a draw-in roller of an opening device via an introduction funnel, commonly referred to as a condenser, while the sliver is pressed against the draw-in roller by means of a gripping table during spinning and to an apparatus for manipulated handling of the sliver at the spinning station.
BACKGROUND OF THE INVENTION
In open-end spinning frames, a sliver is drawn into the spinning frame from sliver cans standing below the spinning station. During a can change, or if the sliver breaks below the spinning frame, the sliver must be reintroduced into the funnel to the opening device of the open-end spinning station. This operation can be done manually, but can changing devices are known which utilize a manipulator which can introduce the sliver automatically into the insertion funnel of the opening device of a spinning station. A method as well as a device for the automatic feeding of the sliver are disclosed in German Patent Publication DE 42 04 044 A1.
To increase the productivity of open-end spinning frames, it is customary to clean the spinning stations from time to time, which can be done every time a can change is performed, for example. However, since the spinning of a sliver from a can takes several hours, the degree of soiling after such time can already have reached a state where it reduces spinning production. For this reason, it is customary to perform cleaning of the spinning stations, and of the rotors in particular, in accordance with a preset timed cycle. In this connection it is possible to equip a service device, for example a yarn attachment carriage, with cleaning tools, or to position a device specially provided for cleaning purposes at the respective spinning stations in order to perform the required cleaning work. The ongoing spinning operation is interrupted in this case.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a method and apparatus for improving the cleaning operation in an open-end spinning frame.
Briefly summarized, the present invention accomplishes the foregoing objective by a method for cleaning a spinning station of an open-end spinning frame of the type wherein the sliver is fed to a draw-in roller of an opening device via a sliver condenser and the sliver is held against the draw-in roller by a gripping table during spinning. According to the present invention, the cleaning method basically comprises the steps of stopping the draw-in roller and separating the gripping table from the draw-in roller. An end of the sliver is then aspirated from between the separated draw-in roller and the gripping table by means of a switchable nozzle which can be selectively operated in a suction aspiration mode and a forced air blowing mode. A defined length of the sliver end is retained in a fixed disposition following its removal from between the draw-in roller and the gripping table while the cleaning operation is performed. After the cleaning operation, the sliver end is reinserted between the draw-in roller and the gripping table by means of the aspiration and blower nozzle for restarting the spinning operation.
The present invention also provides a novel manipulator for handling the sliver during a cleaning operation at a spinning station, the manipulator basically comprising a nozzle means for aspirating and blowing a sliver end. The nozzle means has suitable means for picking up the sliver end from and inserting the sliver end into the spinning station utilizing a tubular sliver receiving funnel communicating with a sliver obstructing insert. According to the invention, the insert has a plurality of air flow openings annularly arranged about a air flow line centrally through the funnel. An actuator is also provided for opening the condenser and for inserting the sliver end between the draw-in roller and the gripping table.
Thus, the present invention basically contemplates that the sliver is removed for performing a cleaning operation at a spinning station so that cleaning can also include the sliver feed device. In this manner, improved cleaning results and thus improved spinning results are achieved. The invention discloses the means for performing this improved cleaning automatically. Drawing in of the sliver must be stopped whereby a yarn break automatically occurs. For cleaning the opening device it is necessary to remove the end of the sliver extending into it and, for this purpose, the gripping table is lifted off the draw-in roller, which can be done by means of an actuator disposed on the manipulator for handling the sliver. In accordance with the invention, a combined aspiration and blower nozzle, disposed on the manipulator and extending to the gripping gap between the gripping table and the draw-in roller, aspirates the sliver end and pulls it out of the area of the condenser following the opening of the gripping table to hold the sliver during the cleaning operation.
In a preferred embodiment of the invention, the sliver can be gripped at a defined location below the insertion funnel, i.e.,the so-called condenser, before the sliver is removed, following which the aspiration and blower nozzle can release the end of the sliver so that it hangs over the gripper and can be gripped by the manipulator. The gripper can be disposed either at the spinning station or on the service device which performs cleaning. If the sliver gripper is disposed at the spinning station, the sliver preferably moves through the opened sliver gripper during the spinning operation. When the spinning operation is interrupted, the manipulator actuates the gripper so that the drawing-in of the sliver is stopped and a defined length of sliver is ready for inserting the sliver for the fresh yarn attachment operation. If the gripper is disposed on the service device, the sliver is first grasped by the gripper or it is placed into the gripper and fixed in place therein.
In accordance with the invention, an exactly defined length of sliver extends in both cases from the sliver gripper for the yarn reattachment operation, which can be advantageously grasped at a defined location by the manipulator and thus easily inserted into the spinning station. In this manner, the yarn attachment operation can be directly started with a defined sliver cross section, so that only small amounts of waste are generated in the course of the yarn attachment operation. It is also prevented that the sliver is grasped above its actual end possibly causing sliver loops to be introduced into the spinning station, which can lead to obstructions in the condenser and therefore to additional interruptions of the spinning operation. Unsuccessful gripping steps caused by too short a sliver end are also avoided.
The aspiration and blower nozzle in accordance with the present invention is constructed to directly impart a shape to the aspirated sliver end, which is advantageous for reinsertion into the gripping gap between the gripping table and the draw-in roller. Specifically, the nozzle has a funnel-shaped cross section which imparts a pointed, flame-shaped form to the sliver end, and thereby considerable eases the insertion of the sliver end into the gap between the gripping table and the draw-in roller. The funnel-shaped design of the aspiration and blower nozzle also allows the aspiration of slivers of different sliver cross sections. The tips of the sliver ends are condensed and are given a cone-shaped cross section. Such a shape of the sliver end also makes blowing the sliver end out of the aspiration and blower nozzle and insertion of the blown sliver end into the gripping gap between the gripping table and the draw-in roller easier, because the shape of the sliver end eases its exit from the aspiration and blower nozzle.
According to another aspect of the invention, the aspiration and blowing nozzle has an insert portion formed with an annular arrangement of openings which, when blowing air is supplied to the aspiration and blower nozzle, results in an air flow directed to the outer annular periphery of the sliver tip and in this way aids in blowing the sliver end out of the aspiration and blower nozzle. A centrally disposed opening in the insert aids in the blow-out effect. However, this central opening is considerably smaller than the annular arrangement of openings surrounding it. During the aspiration of the sliver, the insert limits the length to which the sliver is aspirated into the aspiration and blower nozzle.
According to a further aspect of the invention, a screen is placed in front of the insert which effectively prevents the penetration of fibers into the openings of the insert. In this manner, it is prevented that the tip of the sliver end is thinned out by the removal of fibers which are aspirated through the openings of the insert. Furthermore, unnecessary soiling of the pneumatic system of the spinning station is prevented by keeping out the fibers. If, following the blowing out of the sliver end during its insertion into the condenser and introduction into the gripping gap, fibers should be caught in front of the screen, the aspiration and blower nozzle can be cleaned of possibly retained fibers and fiber remnants by blowing them out subsequent to the reinsertion of the sliver.
If the screen is substantially flat so as to extend perpendicularly in respect to the axis of the aspiration and blower nozzle, it has an increased resistance against flow of aspiration or compressed air than if the screen is concavely or semispherically shaped. A concave screen shape favors the desired formation of a tip at the end of the sliver.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one spinning station of an open-end spinning frame in accordance with the present invention with a sliver manipulator positioned on a traveling service device;
FIG. 1a shows an alternative form of service device with a sliver manipulator and a sliver gripper;
FIG. 2 is a cross section through an aspiration and blower nozzle in accordance with the invention;
FIG. 3a is a front elevational view of a perforated insert of the aspiration and blower nozzle;
FIG. 3b is a cross sectional view through a perforated insert of the type of FIG. 3A and a flat screen insert disposed in combination with each other;
FIG. 3c is a front elevational view of a screen insert of the aspiration and blower nozzle;
FIG. 3d is a cross sectional view through a perforated insert of the type of FIG. 3a and a convex, semispherically-shaped screen insert disposed in combination with one another;
FIG. 3e is a cross sectional view through a perforated insert of the type of FIG. 3a and a semispherically-shaped, concave screen insert; and
FIG. 4 is a schematic circuit diagram of the compressed air supply system for the aspiration and blower nozzle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, a spinning station 1 of an open-end spinning frame 2 of the type which comprises a plurality of spinning stations arranged in alignment to each other is shown in side view. Only those characteristics aiding in understanding the invention are represented and described.
A so-called spinning box 3 is located at each of the spinning stations, into which the sliver 4 is introduced via an insertion funnel 6 for the sliver, commonly referred to as a so-called condenser, from sliver cans 5 placed underneath the spinning boxes 3. The condenser 6 is seated pivotably on a shaft 7 in the housing of the spinning box 3. It is advantageous for purposes of the present invention if the condenser 6 has a design which corresponds to the sliver feed device represented in FIG. 8 of German Patent Publication DE 42 04 044 A1. The condenser 6 has a gripping table 9 which is pressed against a draw-in roller 10 by means of a spring 8. The sliver is fed through a sliver gripping gap 11 between the gripping table 9 and the draw-in roller 10 to an opening device 12, in which the sliver 4 is opened in a known manner by means of an opening roller 13 into individual fibers, which are then fed through a fiber guide channel 14 to a spinning rotor 15 wherein the fibers are spun in a known manner into a yarn 16. The yarn is drawn from the rotor 15 by a pair of driven draw-off rollers 18 through a small draw-off tube 17 and is deposited on a cheese 20 by a yarn guide 19. The cheese 20 is held by a pivotable bobbin holder 21 and rests with its circumferential surface on a driven winding roller 22 which thereby drives the cheese.
A service device 23 is shown in FIG. 1 to be positioned in front of the spinning station 1. By way of example, this service device 23 can be a can changing carriage, such as is known from German Patent Publication DE 42 04 044 A1. However, the service device can also be a yarn attachment carriage, a cheese changing carriage or any other form of service device which travels along the spinning frame and can be equipped for the specific purpose of cleaning the spinning stations or the spinning frame. For this reason, this service device is not shown in detail.
The service device 23 is equipped with a sliver manipulator 24 which is also not shown in detail. The manipulator 24 can be extended from the service device 23 to each spinning station 1 via a telescoping carriage 25 as indicated by the two-headed arrow 26. The manipulator 24 has a pivotable head 27 with an aspiration nozzle 28 as well as an actuator 29 for opening the sliver feed device, i.e., the condenser 6, at any one of the spinning boxes 3 for introducing the sliver. The structure of the manipulator 24 in this exemplary embodiment can correspond to the exemplary embodiments represented and described in German Patent Publication DE 42 04 044 A1.
From German Patent Publication DE 42 04 044 A1 it is known how the sliver is inserted at a spinning station by means of the manipulator 24 following a sliver can change. When cleaning a spinning station, the process in accordance with the invention is performed as follows:
The draw-in roller 10 is stopped whereby the feeding of fibers to the rotor 15 is interrupted and the yarn 16 necessarily breaks. Simultaneously with the stoppage of the draw-in roller, the sliver 4 is gripped at a defined location below the condenser 6. A sliver gripper 30 is provided for this purpose below the condenser 6 in the instant exemplary embodiment. The sliver gripper 30 can consist, for example, of two mating gripping elements 31 which can be moved selectively toward and away from one another and are normally open during the spinning operation. These two gripping elements 31 are actuated into engagement against each other by means of motor-driven or electromagnetic actuators 32 for holding the sliver 4 during the cleaning operation. Because the draw-in roller 10 is stopped, a piece of sliver of exactly defined length remains between the sliver gripper 30 and the gripping gap 11.
To be able to perform the cleaning operation, the end of the length of sliver is now removed from the-spinning station by means of the manipulator 24. To do so, the manipulator 24 is moved by means of the telescoping carriage 25 to the spinning box 3 and its pivotable head 27 is positioned in front of the condenser 6. The actuator 29 thereby comes into operational contact with the condenser 6 and lifts the gripping table 9 off the draw-in roller 10, which frees the sliver end in the gripping gap 11. The aspiration and blower nozzle 28 is advanced forwardly at the same time for aspirating the sliver end in the area of the gripping gap 11. This manner of manipulation of the condenser 6 is performed as described in German Patent Publication DE 42 04 044 A1.
The aspiration and blower nozzle 28 with the gripped sliver end is then retracted and releases the sliver end outside of the area of the condenser 6, so that the sliver end hangs downwardly over the sliver gripper 30. Since the sliver removed from the spinning box 3 has a defined length, it can always be grasped by the manipulator 24 at the same location and inserted into the spinning station for renewed yarn attachment.
Instead of being disposed on the spinning station itself, the sliver gripper 30 for holding the sliver can alternatively be disposed on the service device 23. This option is represented in FIG. 1a wherein a sliver gripper 130 is fastened below the manipulator 24 by means of an extensible and retractable holder 33. The two gripping elements 131, which can be opened and closed by means of the actuators 132, can be positioned by means of the holder 33 at a location below the condenser 6 for grasping the sliver 4. When the sliver 4 has been gripped, which is determined by means of a sensor (not shown ), the manipulator 24 is extended and opens the condenser 6 by means of the actuator 29 so that the aspiration and blower nozzle 28 can grip the sliver end remaining in the gripping gap 11. After the sliver end has been pulled out of the gripping gap 11, the manipulator 24 can be retracted and the aspiration and blower nozzle 28 can release the end of the sliver. The sliver end 4e then will hang over the sliver gripper 130 by a defined length, as illustrated in FIG. 1a. For reinsertion into the spinning box 3, the pivotable head 27 with the aspiration and blower nozzle 28 pivots downward and grips the tip 4s of the sliver end which, because of its defined length, always hangs at the same place and can therefore easily be gripped and aspirated by the aspiration and blower nozzle 28.
It is also possible that no form of sliver grippers 30 or 130 are provided, in which case the aspiration and blower nozzle 28 must maintain an aspirated grip on the sliver end during the entire cleaning operation.
An exemplary embodiment of an aspirating nozzle 28 in accordance with the present invention is illustrated in FIG. 2. The aspirating nozzle 28 consists of a tube 34 made of an elastic material, for example an elastic plastic material. In the present case, the tube has an exterior diameter of approximately 6 mm and an interior aspiration cross section of approximately 4 mm. The free end of the aspirating tube 28 widens over a distance of approximately 30 mm in the shape of a funnel 35, terminating in a mouth 36 of the funnel 35 which has an interior diameter of about 6 mm. The length of the funnel 35 as well as the diameter of the mouth and the usable interior diameter of the aspiration cross section can be adapted to the sliver which is to be processed, the thickness and the diameter of the sliver constituting the determinative factors for the design of the aspirating opening 36 and the funnel 35.
An insert 37 of approximately 5 mm length is fitted within the tube 34 at the transition between the funnel 35 and the tube 34 and is formed with bores 38 which are positioned in an annular arrangement around a central bore 39. The diameter of the bore 39 is less than the diameters of the annularly arranged bores 38. A screen 40 of a semispherical, convex shape is affixed at the front of the insert 37 facing the mouth 36 of the funnel 35.
Several exemplary embodiments for the combination of inserts 37 and screens are illustrated in FIGS. 3a to 3e.
FIG. 3a shows a front elevational view of an insert 37 having a screen 140, which is substantially flat in contrast to the exemplary embodiment in FIG. 2, affixed to the front of the insert 37. The combination of the insert 37 with this flat screen 140 is illustrated in FIG. 3b in an axial section longitudinally through the insert 37 taken along the section line B--B shown in FIG. 3a. The front elevation of FIG. 3a likewise is taken along the section line A--A of FIG. 3b.
The front view of the insert 37 in FIG. 3a shows a number of bores 38 of substantially equal size formed in the front face of the insert and extending axially in parallel relation to one another along the length of the insert 37, the bores 38 being arranged annularly around a centrally disposed bore 39. In the present exemplary embodiment, the diameter of the central bore 39 is approximately one half of the diameters of the bores 38. As a result, a greater aspiration force is exerted by the aspiration flow on the constituent fibers of the sliver at its annular periphery than on the fibers at the central area within the sliver. Similarly, when blowing out the aspirated sliver, a greater pressure force is exerted on the annularly outwardmost fibers, so that the sliver, which becomes denser through the funnel 35 towards the tip, can be released more easily from the funnel 35.
As can be seen in FIG. 3b, the flat screen 140 is disposed in front of the insert 37 at a defined spacing from the front end of the insert 37, facing the funnel 35. FIG. 3c shows a top view of the screen 140.
In an alternative exemplary embodiment shown in FIG. 3d, a semispherically concave screen 40 is fitted on the front end of the insert 37. In comparison with the screen 140 in accordance with the embodiment in FIGS. 3a, 3b and 3c, the screen 40 in accordance with the embodiment in FIG. 3d hinders the throughput of air and thus the flow of the blowing or aspirating air is relatively lessened. FIG. 3e illustrates another embodiment wherein a semispherically-shaped screen 240 is disposed with its concave side facing the funnel 35.
The shape of the screens has an effect on the shaping of the tip of the sliver, i.e., the free end of the sliver, when it extends up to the screen. With a flat screen 140, the tip of the sliver is caused to flatten. With a screen 240 corresponding to FIG. 3e, the tip of the sliver is caused to become rounded.
The screens have the function of preventing the aspiration of the sliver into the insert 37. Furthermore, the screen constitutes a rough barrier against the aspiration of individual fibers into the tube 34. In addition, the exact length between the sliver end and the sliver gripper 30 or 130 is defined by means of the screen. When aspirating air is applied, the sliver is pulled into the funnel 35 and becomes denser, while the tip of the sliver is shaped conically. The screens form a barrier against continued aspiration of the sliver. Blowing out the sliver is aided by the arrangement of the openings in the insert 37 and by the funnel shape of the aspiration and blower nozzle. The blowing times can be kept very short, for example 30 msec, since the screen-shaped, compressed sliver end is quickly released. The arrangement of the bores 38 of the insert 37 allow a defined, flame-shaped air flow around the sliver during the blowing operation. When being inserted in the spinning box 3, the sliver end is thusly deposited in a flame shape when placed on the gripping table 9 in the area of the gripping gap 11. A reliable gripping of the sliver between the draw-in roller 10 and the gripping table 9 is thereby achieved.
A pneumatic circuit diagram for the actuation and operation of the aspiration and blower nozzle 28 of the manipulator 24 is represented in FIG. 4. The service device 23, which is not shown, is supplied with compressed air from a central pneumatic supply line 42 of the spinning frame via a connection 43 through a branch line 44. Negative air pressure, i.e. suction, is required for aspirating the sliver end, which can be generated by directing compressed air to a vacuum aspiration nozzle as is represented symbolically at 45. A 5/2-way valve is placed upstream of this vacuum aspiration nozzle 45, which can be switched by a control device (not shown). In the present exemplary embodiment the compressed air line 44 is connected with a pneumatic line 47, which terminates at the connection point P forming the pressure connection of the vacuum aspiration nozzle 45. The compressed air flows through the vacuum aspiration nozzle 45, exits at the connection point R, which forms an outlet connection of the nozzle 45, and flows to the ambient atmosphere through the line 48. Negative pressure is thusly generated at the connection U, thereby forming the suction connection of the vacuum aspiration nozzle 45. A line 49 extends from the suction connection U to the pivotable head 27 of the manipulator 24 and terminates in the aspiration and blower nozzle 28.
If the 5/2-way valve 46 is actuated so that the compressed air line 44 is connected with the line 48, the outlet of the line 47 is blocked by the valve. The incoming compressed air therefore does not flow through the vacuum aspiration nozzle from the connection R to P, but instead enters the line 49 through the connection U. In this manner, the vacuum aspiration nozzle becomes a blower nozzle in contrast to its normal function and compressed air is caused to exit the aspiration and blower nozzle 48 whereby it operates as a blower nozzle. This circuitry as well as the use of a 5/2-way valve simplify the pneumatic installation in comparison with the alternative of utilizing two 3/2-way valves and associated controls.
A filter 50 is installed in the line 49 to prevent the entry of fibers which could be removed from the sliver during the application of suction to the aspiration and blower nozzle 48 and thereby drawn into the pneumatic installation.
A pressure switch 51 is also connected to the line 49 to actuate in response to increase in the negative pressure in the line 49 after the sliver is aspirated by the aspiration and blower nozzle 48 and enters the funnel 35. The increase in the suction pressure condition is reported via a signal line 52 to a control device (not shown) to indicate that the sliver has been properly aspirated. Thereupon, subsequent operating steps of the manipulator 24 can be actuated, for example, the reinsertion of the sliver into the spinning station or the release of the sliver when the sliver has just been aspirated out of the spinning station to make the spinning station available for cleaning. If the signals transmitted from the pressure switch to the control device indicate that the sliver has not been aspirated after a defined length of time, it is possible, for example, to perform additional searching movements for the sliver by means of the manipulator.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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Spinning stations of open-end spinning frames are cleaned from time to time to increase productivity, e.g. each time a sliver can change is made although, if the times between the exchange of two cans are too long, cleaning may be performed at a preset cycle. The sliver must be removed from the spinning station for this purpose. To be able to reintroduce a defined length of the removed sliver into the spinning station at the end of a cleaning operation, the end of the sliver is aspirated from between the draw-in roller and the gripping table of the spinning station by means of an aspiration and blower nozzle and pulled out of the spinning box of the spinning station and, after the cleaning operation, the sliver is introduced into the spinning station by means of the aspiration and blower nozzle. The aspiration nozzle has an insert with bores for causing the tip end of the sliver to assume a particular shape.
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[0001] This application is a continuation of U.S. patent application Ser. No. 11/354,304, entitled “METHOD AND APPARATUS FOR REDUCING POWER CONSUMPTION IN A MEMORY BUS INTERFACE BY SELECTIVELY DISABLING AND ENABLING SENSE AMPLIFIERS,” filed on February, 2006, which is a continuation of U.S. Pat. No. 7,000,065, entitled, “METHOD AND APPARATUS FOR REDUCING POWER CONSUMPTION IN A MEMORY BUS INTERFACE BY SELECTIVELY DISABLING AND ENABLING SENSE AMPLIFIERS,” which issued on Feb. 14, 2006.
BACKGROUND
[0002] The invention generally relates to power reduction in a memory bus interface.
[0003] Computer systems use memory devices to store data that is associated with various operations of the system. Collectively, these devices may form the system memory for the computer system. To store data in and retrieve data from the system memory, the computer system typically includes a memory controller that is coupled to the system memory via a memory bus. The signals that propagate over the memory bus depend on the type of memory devices that form the system memory.
[0004] For example, one type of memory device is a synchronous dynamic random access memory (SDRAM), a device in which data signals are communicated to and from the SDRAM device over the memory bus in synchronization with positively sloped, or positive going, edges (for example) of a clock signal. This basic type of SDRAM is known as a single data rate (SDR) SDRAM, as the data is clocked once every cycle of the clock signal. In contrast to the single data rate SDRAM, in the operation of a double data rate (DDR) SDRAM, data is clocked both on the positive going and negative going edges of a clock signal (called a data strobe signal), thereby giving rise to the phrase “double data rate.”
[0005] The data strobe signal, called the “DQS data strobe signal,” is furnished either by the system memory or the memory controller, depending on whether a read or write operation is occurring over the memory bus. A SDR SDRAM device does not use the DQS data strobe signal. In a write operation with a DDR SDRAM device, the memory controller furnishes bits of data to the memory bus by controlling the logic levels of data bit lines (called the “DQ data bit lines”) of the memory bus. In the write operation, the memory controller furnishes the DQS data strobe signal such that each edge of the DQS data strobe signal is synchronized to a time at which a particular set of data bits (furnished by the memory controller via the DQ data bit lines) is valid on the memory bus. In this manner, the memory controller may offset the phase of the DQS data strobe signal relative to the data bit signals so that the edges of the DQS data strobe signal occur when the particular set of data bits are valid. For example, the DQS signal may be ninety degrees out of phase with the signals present on the DQ data bit lines. Thus, for example, the memory controller furnishes a first set of bits to the memory bus. When these bits are valid, the DQS data strobe signal has a positive going edge. The memory controller furnishes the next set of bits to the memory bus. When these bits are valid, the DQS data strobe signal has a negative going edge, etc.
[0006] For a read operation, the above-described role is reversed between the DDR SDRAM device and the memory controller. In this manner, for a read operation, the DDR SDRAM device furnishes both the DQS data strobe and controls the signals that appear on the DQ data bit lines.
[0007] When neither a write nor a read operation is occurring over the memory bus, DQ data bit lines as well as the DQS data strobe lines remain at a termination level, a level that may be, for example, between the logic zero and logic one voltage levels. Thus, a potential difficulty with this arrangement is that an input sense amplifier of the memory controller (for example), which receives and amplifies the signal from one of the DQ data bit lines, may use a reference voltage near the termination level. It is this reference voltage that the sense amplifier uses to distinguish a logic one voltage (i.e., a voltage greater than the reference voltage) from a logic zero signal (i.e., a voltage less than the reference voltage). Thus, noise on a particular DQ data signal line may inadvertently appear as a logic one or logic zero voltage to the associated sense amplifier when neither a write nor a read operation is actually occurring over the memory bus. This event may cause inadvertent operation of the sense amplifier and thus, excess power may be dissipated by the amplifier and possibly other circuitry of the memory controller due to this operation.
[0008] Thus, there is a continuing need for an arrangement and/or technique to address one or more of the problems that are stated above.
BRIEF DESCRIPTION OF THE DRAWING
[0009] FIG. 1 is a schematic diagram of a computer system according to an embodiment of the invention.
[0010] FIG. 2 is a schematic diagram of a memory controller hub according to an embodiment of the invention.
[0011] FIG. 3 is a schematic diagram of a memory controller according to an embodiment of the invention.
[0012] FIGS. 4 , 5 , 6 , 7 , 8 , 9 and 10 are waveforms depicting signals of the computer system according to an embodiment of the invention.
[0013] FIG. 11 is a schematic diagram of control circuitry for a sense amplifier according to an embodiment of the invention.
[0014] FIG. 12 is a schematic diagram of a memory device according to an embodiment of the invention.
DETAILED DESCRIPTION
[0015] Referring to FIG. 1 , an embodiment 10 of a computer system in accordance with the invention includes a system memory 22 for storing various data associated with the operation of the computer system 10 . The system memory 22 is formed from a collection of semiconductor memory devices. As an example, the system memory 22 may include double data rate (DDR) synchronous dynamic random access memory (SDRAM) devices.
[0016] The devices of the system memory 22 communicate with a north bridge, or memory controller hub 16 , via a memory bus 20 . In this manner, the memory bus 20 includes various address, control and data signal lines that are associated with communicating bits of data between the memory controller hub 16 and the system memory 22 . The memory controller hub 16 , in turn, serves as an interface between the rest of the computer system 10 and the system memory 22 , and as this interface, furnishes signals to the memory bus 20 to control the reading and writing of data to and from the system memory 22 . To accomplish this, the memory controller hub 16 includes a memory controller 18 that forms an interface for the memory controller hub 16 for communications with the system memory 22 .
[0017] For purposes of reducing the power that is otherwise consumed by the memory controller 18 during times when no read operations are occurring between the memory controller 18 and the system memory 22 , the memory controller 18 disables its input data sense amplifiers (not shown in FIG. 1 ) during these times. These sense amplifiers detect data on the data lines (called “DQ data bit lines”) of the memory bus 20 during a read operation and provide signals (indicative of this data) that are sampled by a read buffer (not shown in FIG. 1 ) of the memory controller 18 .
[0018] When not being used during a read or write operation, the voltage of each DQ data bit line is set to a termination level, a level between the logic one and logic zero levels.
[0019] However, each input sense amplifier of the memory controller may use a reference voltage near the termination level. It is this reference voltage that each sense amplifier uses to distinguish a logic one voltage (i.e., a voltage greater than the reference voltage) from a logic zero signal (i.e., a voltage less than the reference voltage). Thus, noise on a particular DQ data signal line may inadvertently appear as a logic one or logic zero voltage to the associated sense amplifier when neither a write nor a read operation is actually occurring over the memory bus. This event may cause inadvertent operation of the sense amplifier, if not for the disablement of these sense amplifier, as described below.
[0020] As a more specific example, in some embodiments of the invention, the logic one voltage may be approximately 2.5 volts; the logic zero voltage may be approximately zero volts; and the termination and reference voltages may be approximately 1.25 volts. Other voltage levels may be used in other embodiments of the invention.
[0021] By disabling the sense amplifiers of the memory controller when a write or read operation is not occurring over the memory bus 20 , the sense amplifiers do not respond to noise that is present either on the DQ data bit lines of the memory bus 20 . As a result, the sense amplifiers only respond to the DQ data bit lines during a particular read operation, when their associated DQ data bit lines are driven from the termination level to either a logic one or a logic zero level.
[0022] More particularly, FIGS. 4 and 5 illustrate the signals present on a data bit line ( FIG. 4 ) and the DQS data strobe line ( FIG. 5 ) during a burst read operation in which a predetermined number (two, four or eight, for example) of bits of data are received in sequence over each DQ data bit line. The memory controller may be configured to the number of bits that are transferred in each burst. In the example described herein, each DQ data bit line communicates four bits of data in sequence in a burst read operation.
[0023] In this example, the first bit of data (bit D0) that is furnished by the system memory 22 occurs at time T 0 , a time at which the system memory 22 also asserts the DQS data strobe, as depicted in FIG. 5 . At time T 2 , the system memory 22 begins furnishing a signal to the DQ bit line indicative of a D1 bit of data and synchronously deasserts the DQS data strobe signal. This process continues for the remaining two bits. For example, at time T 4 , the system memory 22 asserts the DQS data strobe signal and begins furnishing a signal to the DQ data bit signal line indicative of the D2 bit of data. Thus, as can be seen from FIGS. 4 and 5 the generation of the D0, D1, D2 and D3 data bits occurs in synchronization with alternating edges of the DQS data strobe signal.
[0024] For purposes of sampling each data bit from the DQ data bit line, the memory controller 18 shifts, or delays the DQS data strobe signal to align each edge of the DQS data strobe signal with the data eyes of the associated data signal. The term “data eye” refers to the portion of the data signal in which the data signal indicates a particular bit of data. Thus, the “data eye” would not include the portions of the data signal in which the data signal transitions between logical states.
[0025] The net effect of the alignment of the DQS data strobe signal with the data eyes of the data signals is that the memory controller 18 delays the DQS data strobe signal to produce an internal, delayed DQS data strobe signal that is depicted, as an example, in FIG. 7 . Thus, as can be seen from FIG. 7 , the first positive going edge of the delayed DQS data strobe signal (that appears at time T 2 ) is aligned approximately in the center of the data eye of the portion of the DQ signal that indicates the DO data bit, the subsequent negative going edge of the delayed DQS data strobe signal is aligned in the center of the data eye that indicates the D1 data bit, etc. Ideally, the delay centers the strobe's edges in the data eyes, but the delay may deviate from this ideal relationship due to system and memory controller timing effects. Nevertheless, there is still a delay between the DQS data strobe signal and the delayed DQS data strobe signal.
[0026] The memory controller 18 enables its input read sense amplifiers in response to the beginning of a read operation. The memory controller 18 , in response to the end of the read operation, disables its sense amplifiers, thereby preventing unnecessary consumption of power.
[0027] Thus, for the above-described read operation, the memory controller 18 may behave in the following fashion. Before time T 0 in this example, no read operation is occurring, therefore, the memory controller 18 disables its sense amplifiers. However, at time T 0 the read operation begins, as the data signals (such as the DQ signal depicted in FIG. 4 ) and the DQS data strobe signal ( FIG. 5 ) appear at the memory controller on the DQ and DQS lines. These signals are generated by the system memory 20 . Slightly before or at time T 0 , logic of the memory controller 18 recognizes the beginning of the read operation and deasserts an end of byte signal called EOB. ( FIG. 9 ). As described below, the memory controller 18 , in some embodiments of the invention, asserts an inverted sense amplifier enable signal called EN# ( FIG. 10 ) in response to the deassertion of the EOB signal to enable the input sense amplifiers. The enablement of the sense amplifiers occurs before the leading positive going edge of the delayed DQS data strobe signal, as depicted in FIGS. 6 and 7 . Thus, when read buffers of the memory controller 18 respond to the edges of the delayed DQS data strobe signal to begin sampling the data bits, the sense amplifiers have already been enabled, thereby permitting the sense amplifiers to furnish an indication of the signal on the associated data bit line to the data buffers.
[0028] FIG. 8 depicts the sampled data inside the read buffers of the memory controller 18 . In this manner, at time T 2 , in response to the positive going edge of the delayed DQS data strobe signal, the read buffer samples the DO bit, and thus, the sampled DO bit appears in the read buffer beginning at time T 2 . The D2, D3 and D4 bits are sampled in sequence in a similar manner.
[0029] Referring to FIG. 2 , in some embodiments of the invention, the memory controller hub 16 may include the memory controller 18 to communicate with the memory bus 20 ; a system bus interface 70 to communicate with a system bus 14 of the computer system 10 ; an Accelerated Graphics Port (AGP) bus interface 74 to communicate with an AGP bus 26 ( FIG. 1 ) of the computer system; and a hub interface 72 to communicate with a south bridge, or I/O hub 40 , of the computer system. The AGP is described in detail in the Accelerated Graphics Port Interface Specification, Revision 1.0, published on Jul. 31, 1996, by Intel Corporation of Santa Clara, Calif. The memory controller 18 , system bus interface 70 , AGP bus interface 74 and hub interface 72 are all coupled together to communicate data to various parts of the computer system 10 .
[0030] Referring to FIG. 3 , in some embodiments of the invention, the memory controller 18 includes a data interface 100 , an address interface 130 and a control signal interface 134 . The address interface 130 includes communication lines 133 for driving address signals onto the memory bus 20 to initiate a particular read or write operation. The control signal interface 134 includes signal communication lines 140 to drive the appropriate drive control signals on the memory bus 20 to initiate a particular read or write operation. The address interface 130 , control signal interface 134 and data interface 100 are all coupled to a control circuit 142 that controls and coordinates the general operations of the memory controller 18 .
[0031] The data interface 100 includes write path circuitry 120 for purposes of writing data to the system memory 22 . In this manner, the write path circuitry 120 is coupled to the other circuitry of the memory controller hub 16 via communication lines 113 and is in communication with the memory bus 20 via communication lines 124 .
[0032] The data interface 100 also includes a circuitry associated with the read path of the data interface 100 . In this manner, the data interface 100 includes sense amplifiers 102 that are coupled to receive data bit line signals (called DQ[0:63], which represents sixty-four DQ data bit lines as an example) from respective data bit lines 104 of the memory bus 20 .
[0033] The enablement/disablement of the sense amplifiers 102 is controlled by a sense amplifier control circuit 114 . In this manner, as further described below, in response to the beginning of a read operation, the sense amplifier control circuit 114 enables the sense amplifiers 102 , and in response to the end of a particular read operation (and no subsequent read operation), the sense amplifier control circuit 114 disables the sense amplifiers 102 .
[0034] To detect the beginning and ending of a particular read operation, in some embodiments of the invention, the sense amplifier control circuit 114 receives the EOB signal from the control circuit 142 . The EOB signal is asserted (driven high, for example) to indicate the end of a read operation, such as the end of a read burst operation, for example; and the EOB signal is deasserted (driven low, for example) to indicate the beginning of the read operation. In response to the assertion of the EOB signal, the sense amplifier control circuit 114 disables the sense amplifiers 102 .
[0035] Among the other circuitry of the data interface 100 , the data interface 100 , in some embodiments of the invention, includes a delay circuit 108 that is coupled to the DQS data strobe line 106 to receive the DQS data strobe signal. The delay circuit 108 delays the DQS data strobe signal to produce a delayed data strobe signal (such as the signal depicted in FIG. 8 ) that appears on a clock signal line 103 that clocks operations of a data buffer 112 , as further described below. In some embodiments of the invention, the delay circuit 108 delays the DQS data strobe by one quarter period of a system clock signal (called SCLK). The SCLK system clock signal, in turn, may be used, for example, on the output side of the read data buffer 112 to read the sample data from the read data buffer 112 . Furthermore, the frequency of the SCLK signal may be approximately the same as the frequency of the DQS strobe signal when driven.
[0036] The read data buffer 112 includes input lines 105 that are coupled to the output terminals of the sense amplifiers 102 . In response to a particular edge (a positive going edge or a negative going edge) of the delayed DQS data strobe signal, the read data buffer 112 samples the signals present on the output terminals of the sense amplifiers 102 , latches the samples and stores them for retrieval from the read data buffer 112 . For purposes of illustration, it may be assumed that the stored data may be retrieved from the read data buffer 112 in synchronization with the SCLK system clock signal. However, other variations may be used.
[0037] FIG. 11 depicts circuitry 200 associated with each data bit line 104 in accordance with an embodiment of the invention. In the various embodiments of the invention, the circuitry 200 may be replicated for each data bit line 104 . In this circuitry 200 , the sense amplifier control circuit 114 includes a D-type flip-flop 154 that furnishes (at its non-inverted output terminal) a signal that is used to disable one of the sense amplifiers 102 in response to the end of a particular read operation.
[0038] More particularly, near the conclusion of a particular read operation, the flip-flop 154 drives its non-inverted output terminal high. This event, in turn, causes a signal (called EN# and depicted in an example in FIG. 10 ) that is received by the inverted enable terminal of the sense amplifier 102 to be deasserted (driven high, for example) to disable the sense amplifier 102 .
[0039] As depicted in FIG. 9 , the flip-flop 154 receives the EOB signal at its input signal terminal, and the clock terminal of the flip-flop 154 is connected to the output terminal of an inverter 152 that receives the internal read delay DQS data strobe signal, i.e., the input terminal of the inverter 152 is coupled to the communication line 103 . The flip-flop 154 is clocked on the positive going edges of the clock signal present at its clock terminal. Therefore, the flip-flop 154 is clocked on the negative going edges of the delayed DQS signal. The non-inverted output terminal of the flip-flop 154 is coupled to one input terminal of an AND gate 107 , and the output terminal of the AND gate 107 furnishes the EN# signal.
[0040] The memory controller 18 uses the circuitry 200 in the following manner. In a particular read operation (a burst read operation, for example) before the last negative going edge of the DQS data strobe signal, the control circuit 142 asserts (drives high, for example) the EOB signal. For the example depicted in FIG. 9 , the control circuit 142 asserts the EOB signal around time T 5 . The flip-flop 154 responds to the negative going edge of the delayed DQS data strobe signal by driving high the voltage of its non-inverted output terminal. This causes the AND gate 107 to deassert (drive high, for example) the EN# signal. For the example depicted in FIG. 10 , this deassertion of the EN# signal occurs at time T 6 . Therefore, in response to the last negative going edge of the delayed DQS data strobe signal, the flip-flop 154 disables the sense amplifier 102 .
[0041] To enable the sense amplifier 102 at the beginning of a read operation, the AND gate 107 receives the EOB signal. Thus, due to this arrangement, in response to the deassertion of the EOB signal, the EN# signal is asserted (driven low, for example). In the example depicted in FIGS. 9 and 10 , the EN# is fully asserted and the EOB signal is fully deasserted at or before time T 0 before the data bits are valid.
[0042] By the time the EOB signal is asserted (driven high, for example) to indicate the end of the read burst, the flip-flop 154 has already asserted its non-inverting output terminal, thereby producing a logic one signal at one of the input terminals of the AND gate 107 . Thus, it is the last negative going edge of the delayed DQS strobe signal that produces the additional logic one signal at the other input terminal of the AND gate 107 to cause deassertion of the EN# signal and disablement of the sense amplifier 102 .
[0043] The circuitry 200 depicted in FIG. 11 also includes latches 150 and 151 , circuitry of the read data buffer 112 . In this manner, the read data buffer 112 includes the latches 150 and 151 for each data bit line of the memory bus 20 . The latch 150 captures its input from the output terminal of the sense amplifier 102 in synchronization with the negative going edge of the delayed DQS data strobe signal, and thus, its latching trigger input terminal is coupled to the input terminal 103 of the buffer 152 . The latch 151 captures its input from the output terminal of the sense amplifier 102 in synchronization with the positive going edge of the delayed DQS data strobe signal, and thus, its latching trigger input terminal is coupled to the input terminal 103 of the buffer 152 . The non-inverting output terminals of the latches provide signals indicative of captured bits of data to respective communication lines 113 .
[0044] Other embodiments within the scope of the following claims. For example, the circuitry of the memory controller 18 may be used in a similar fashion in a particular memory device of the system memory 22 . In this manner, referring to FIG. 12 , in some embodiments of the invention, a particular system memory device 220 may include, for example, the data interface 100 described above in connection with the memory controller 18 . Thus, for these embodiments, instead of disabling the sense amplifiers of the memory device in response to the absence of a read operation, the interface 100 disables the memory device 220 in the absence of a write operation, i.e., an operation in which data is received from the memory controller 18 . Other variations are within the scope of the following claims.
[0045] Referring back to FIG. 1 , among the other features of the computer system 10 , in some embodiments of the invention, the computer system includes a processor 12 (one or more microprocessors, for example) that is coupled to the system bus 14 . The processor 12 may, for example, execute instructions to initiate read and write operations with the system memory 22 . The computer system 10 may also include a display driver 30 that is coupled to the AGP bus 26 as well as a display 32 that is driven by signals from the display driver in response to communications over the AGP bus 26 .
[0046] The memory controller hub 16 may communicate over the hub link 34 to the I/O hub 40 that, in turn provides an interface to an I/O expansion bus 42 and a Peripheral Component Interconnect (PCI) bus 60 . The PCI Specification is available from The PCI Special Interest Group, Portland, Oreg. 97214. An I/O controller 44 may be coupled to the I/O expansion bus 42 and may receive input from a mouse 46 and a keyboard 48 . The I/O controller 44 may also control operations of a floppy disk drive 50 . The I/O hub 40 may control operations of a CD-ROM drive 52 as well as control operations of a hard disk drive 54 . The PCI bus 60 may be coupled to a network interface card (NIC) that is connected to a network to establish communications between the computer system 10 and the network. Other variations of the computer system 10 are possible.
[0047] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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A technique includes amplifying data signals from a memory bus interface. The amplified data signals are sampled, and the amplifier is selectively disabled in response to the absence of a predetermined operation occurring over the memory bus. In some embodiments of the invention, the amplification may be selectively enabled in response to the beginning of the predetermined operation over the memory bus.
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FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to electrophoretic deposition and, more particularly, to a method for the electrophoretic deposition of monolithic and laminated green bodies.
Precisely shaped, small ceramic bodies are used in many applications, including as pitch bonding capillaries in microelectronics, as high temperature nozzles, as ferrules for connecting optical fibers, as high temperature engine components, as dental crowns and as bearing parts. To achieve the precise shaping required for the first application, bonding capillaries, it has been necessary to use the process of cold pressing to fabricate ceramic capillaries.
Multilayer ceramic laminates, made of sequential layers of ceramics such as alumina and zirconia, are known in a variety of geometric shapes, including plates and discs. Applications of ceramic laminates include mechanical seals, automotive engine parts, furnace elements, multilayer and FGM substrates for hybrid circuits, capacitors, RF filters, and microwave components. The processes used to fabricate ceramic laminates include chemical vapor deposition (CVD) and physical vapor deposition (PVD), for layers less than about 1 micron in thickness; tape casting, for layers thicker than about 100 microns; and electrophoretic deposition (EPD), for layers between about 1 micron and about 100 microns in thickness, as will now be described.
Electrophoresis is a process in which charged ceramic particles suspended in a liquid medium are attracted to an electrode when an electrical field is imposed on the particles. EPD is the process of depositing a body of a desired shape on an electrode, using electrophoresis. EPD has long been used to form green ceramic bodies. In particular, EPD has been used by Sarkar, Haung and Nicholson (Electrophoretic deposition and its use to synthesize Al 2 O 3 /YSZ micro-laminate ceramic composites, Ceram. Eng. Sci. Proc. vol. 14 pp. 707-716 (1993)) to deposit laminated composites of alumina and yttria-stabilized zirconia (YSZ).
There is thus widely recognized need for, and it would be highly advantageous to have, a method of EPD that can be used in the fabrication of small, precisely shaped ceramic bodies such as connecting ferrules, orifices and micro-tubes.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a method for electrophoretic deposition of ceramic particles as a green body, including the steps of: (a) forming a first suspension of the ceramic particles in a first polar organic solvent, the ceramic particles constituting at least about 20% of the first suspension by weight; and (b) passing a first direct electrical current through the first suspension, using a deposition electrode.
According to the present invention, there is provided a green body formed of ceramic particles and having a green density of at least 70% of theoretical.
According to the present invention, there is provided a laminated ceramic body including alternating layers of a first composition and a second composition, the first composition having a higher proportion of alumina and a lower proportion of zirconia than the second composition, each of the layers of the first composition having a thickness between about 20 microns and about 40 microns, and each of the layers of the second composition having a thickness between about 30 microns and about 50 microns.
In the formation of ceramic green bodies by EPD, the ceramic particles may be positively charged, in which case they are deposited on the cathode; or they may be negatively charged, in which case they are deposited on the anode. The electrode on which the ceramic particles are deposited is referred to herein as the "deposition electrode". In the examples given herein, the deposition electrode is the cathode, but it will be understood that the scope of the present invention includes the deposition by EPD of negatively charged ceramic particles, so that the deposition electrode is the anode. A small ceramic article such as a bonding capillary or a micro-tube is formed by deposition on a deposition electrode having an external shape identical to the desired internal shape of the capillary. The green body must be sufficiently dense and rigid to retain its shape as it is removed from the deposition electrode and prepared for sintering. To achieve the necessary mechanical strength, the green body may be deposited on the deposition electrode in microlayers, as taught by Sarkar, Haung and Nicholson. This alone, however, is insufficient to give the green body the required rigidity.
Sarkar, Haung and Nicholson used suspensions that included up to 10% by weight of ceramic in polar organic liquids such as ethanol, and obtained green bodies with densities of about 60% of theoretical. Surprisingly, it has been found that using denser suspensions, including from about 20% to about 70% by weight of ceramic, allows the deposition by EPD of both laminated and monolithic green bodies, with densities of 70% and higher of theoretical, that retain their shape when removed from the deposition electrode and sintered. To achieve this green body density in a monolithic green body, it is necessary first to wash the ceramic powders repeatedly in a polar solvent such as deionized water, until the conductivity of the used washing solvent is essentially the same as the original conductivity of the washing solvent. The utility of this washing step in the production of denser monolithic green bodies is believed to be related to the consequent reduction in the ionic conductivity of the suspension. This washing step is optional in the case of laminated green bodies. Preferably, the washed powders are dried before being added to the polar organic solvent to form the suspension.
Suspensions and slurries with higher concentrations of ceramic particles have been used to form green bodies by tape casting. For example, Chartier, Merle and Besson (Laminar ceramic composites, J. Eur. Ceram. Soc. Vol. 15 pp. 101-107 (1995)) used a slurry of greater than 60% ceramic in an azeotropic mixture of methyl ethyl ketone and ethanol to form alumina-zirconia laminates by tape casting. Tape casting is not suitable for fabricating the ceramic bodies of the present application, because, as noted above, tape casting is restricted in practice to layers thicker than about 100 microns, and to flat geometries. Kerkar et al., in U.S. Pat. No. 5,194,129, teach the manufacture of optical ferrules by EPD, using aqueous suspensions of ceramic particles that contained about 40% to 50% by weight of ceramic. Aqueous suspensions are not suitable for the present application because they are subject to electrolysis, leading to the formation of hydrogen bubbles at the cathode and a consequent decrease in the density and local uniformity of a green body deposited thereon.
A laminated green body is formed by EPD by using two or more suspensions of differing global compositions, and alternately placing the electrodes in each of the suspensions, until the desired number of microlayers is deposited. By "global composition" is meant the composition of the ceramic component of the suspension taken as a whole. For example, a suspension of 80% Al 2 O 3 and 20% ZrO 2 has a different global composition than a suspension of 40% Al 2 O 3 and 60% ZrO 2 , even though the individual Al 2 O 3 and ZrO 2 particles of the two suspensions are identical in composition. The microlayers are deposited at a constant current density, as taught by Sarkar, Haung and Nicholson, in order to achieve a constant rate of deposition.
The method of the present invention confers the following advantages on the resulting ceramic bodies:
Precisely controlled shape
Uniform and parallel layers in laminates
High strength and toughness, in the case of multilayer laminates
Fine, stress-free microstructure
Near net shaped products
In addition, the method is more cost effective and less wasteful of raw materials than other methods known in the art, is environment-friendly and can be automated in a straightforward manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is of a method of electrophoretic deposition that can be used to form green bodies of precisely controlled shapes. Specifically, the present invention can be used in the fabrication of pitch bonding capillaries.
The principles and operation of electrophoretic deposition according to the present invention may be better understood with reference to the following description.
The scope of the present invention includes particles of all suitable ceramics, both oxides and non-oxides. Non-limitative examples of suitable ceramics include alumina, zirconia (including YSZ, CESZ and MGSZ), titania, baria and mixtures thereof, such as zirconia-toughened alumina and alumina-toughened zirconia. The particles should be small enough (less than about 1 micron across) to produce a uniform deposit on the cathode.
The preferred polar organic solvents are pure ethanol, pure methyl ethyl ketone and mixtures of ethanol and methyl ethyl ketone in ratios of between 50:50 and 80:20. The most preferred solvent is the 60:40 azeotrope of ethanol and methyl ethyl ketone.
To impose the needed positive surface charge on the ceramic particles, the suspension is ball milled, using ceramic grinding media, for up to 24 hours, or subjected to 20 KHz ultrasound at a power level of up to about 550 watts, for between about 2 minutes and about 15 minutes. Optionally, additives such as pH adjustment agents, dispersants and binders are added to the suspension. The pH adjustment agent can be any suitable organic or inorganic acid that is miscible in the polar organic solvent. The preferred pH adjustment agents are hydrochloric acid and acetic acid. The preferred dispersants are acetylacetone and chloracetic acid, which have been found to allow the deposition, in laminated green bodies, of relatively smooth ceramic microlayers as thick as about 100 microns, in contrast to the prior art microlayer thicknesses of no more than about 20 microns. It should be noted that the preferred microlayer thicknesses, to provide alumina-zirconia laminates of alternating alumina-rich and zirconia-rich layers with maximum strength and toughness, are between about 20 microns and about 40 microns, for the alumina-rich layer, and between about 30 microns and about 50 microns for the zirconia-rich layer. The preferred binders are polyvinyl butyral, nitrocellulose and shellac.
The principle criteria for selecting electrode materials is that they be inert under process conditions and inhibit the evolution of hydrogen gas. If the deposition electrode is a cathode, it may be either consumable or reusable. A consumable cathode is one that is destroyed during the sintering process, so that the green body need not be removed from the cathode before sintering. The preferred materials for a consumable cathode are carbon and electrically conducting polymers. The preferred materials for a reusable cathode arc stainless steel, nickel, aluminum, tungsten carbide and noble metals such as platinum, palladium, silver and gold, and their alloys. The preferred materials for the anode are nickel and noble metals. As noted above, in the production of small ceramic articles such as micro-tubes, the cathode is a wire having a shape identical to the desired interior shape of the ceramic article. Preferably, the anode surrounds the cathode.
Also as noted above, it is necessary to inhibit the production of hydrogen gas at the cathode. In addition to using a polar organic solvent instead of water to form the suspension, this is accomplished by including a hydrogen getter and/or a surface coating on the cathode to absorb hydrogen. Preferred hydrogen getters include palladium and platinum and their alloys. In the case of stainless steel cathodes, a surface coating of a fibrous material such as lens paper has been found by us to be effective for both absorption of hydrogen and facilitating the removal of the green body from the cathode subsequent to the deposition. Removal of the green body from the cathode also is facilitated by polishing the cathode surface before deposition.
The anode and cathode are immersed in the suspension, and a direct electrical current of constant current density, as measured at the cathode, is passed between the electrodes while the suspension is stirred. The preferred range of current densities is between about 0.1 mA/cm 2 and about 5 mA/cm 2 . As noted above, to deposit a laminated green body, several suspensions of differing global composition are used, and the electrodes are moved from one suspension to another as necessary. The deposition time in each suspension depends on the desired microlayer thickness, the current density and the suspension concentration. Typical deposition times for one microlayer range from a few seconds to a few minutes. The total deposition time for a planar laminated green body is on the order of a few hours. The total deposition time for a monolithic or laminated cylindrical body, such as a pitch bonding capillary, having a diameter of a few millimeters is on the order of one minute or less.
Following the deposition, the green body is removed from the cathode, dried in a dessicator, and sintered. Pressureless sintering in air at about 1550° C. for a few hours has been found suitable for the production of stress-free alumina-zirconia laminates. The sintered ceramic body may be machined and/or polished after sintering.
EXAMPLE 1
Multilayer Laminate
A first suspension was prepared by dispersing 270 grams of alumina powder (average particle size 0.4 microns) and 30 grams of zirconia powder (average particle size 0.3 microns) in 1000 ml of an azeotropic mixture of ethanol and methyl ethyl ketone. A second suspension was prepared by dispersing 160 grams of the same alumina powder and 240 grams of the same zirconia powder in 1000 ml of an azeotropic mixture of ethanol and methyl ethyl ketone.
Both suspensions were prepared using 800 ml of the ethanol-methyl ethyl ketone mixture in each, and ball milled for 24 hours, using alumina balls to mill the first suspension and zirconia balls to mill the second suspension. 200 more ml of the ethanol-methyl ethyl ketone mixture was added to each suspension, to bring the total volume of solvent up to the desired 1000 ml. Enough HCl was added to each suspension to adjust the pH of the first suspension to about 7 and the pH of the second suspension to about 6. About 0.5% by volume of acetylacetone dispersant was added to the first suspension. About 1.5% by volume of acetylacetone dispersant was added to the second suspension. About 0.1% by volume of shellac binder was added to each suspension. Each suspension now was transferred to its own electrophoretic cell.
The cathode was a stainless steel plate covered with Wattman lens paper. Each electrophoretic cell was provided with its own half-cylinder nickel anode about 40 mm in radius. The cathode was placed in the first electrophoretic cell at the center of curvature of the anode, and a direct electrical current having a current density of about 0.4 mA/cm 2 was passed between the electrodes for about 45 seconds. The cathode then was removed from the first electrophoretic cell and placed in the second electrophoretic cell, at the same location as before relative to the anode, and the same 0.4 mA/cm 2 of direct electrical current was run between them. This process was repeated for 50 cycles, resulting in the deposition of 100 microlayers, each about 50 microns thick, for a total laminate thickness of about 5 millimeters. A final 50 micron alumina-rich microlayer was deposited in the first electrophoretic cell. The green body was removed from the cathode, dried in a dessicator for a few hours, and sintered in air at 1550° C. for 4 hours. The green body had a density of about 70% of theoretical. The sintered body had an open porosity of between 0.2% and 0.5% by volume. The microhardness of the alumina-rich microlayers, measured by the Vickers method, was about 2400 kg/cm 2 . The microhardness of the zirconia-rich layers was about 2000 kg/cm 2 . The bending strength of the sintered body was about 80 kg/mm 2 .
EXAMPLE 2
Monolithic Capillary
45 grams of alumina (average particle size 0.4 microns to 0.5 microns) and 5 grams of zirconia (average particle size 0.3 microns) were washed repeatedly with deionized water until the conductivity of the wash water fell to about 5 microsiemens/cm. The powders were dried, and enough ethanol was added to bring the total volume to 100 ml. The resulting suspension was ball milled for 4 hours. 0.025 ml of acetylacetone dispersant and 2 ml of a 5% by volume solution of shellac binder in ethanol were added. The suspension was stirred for about 15 minutes and transferred to an electrophoretic cell.
Two different cathodes were used in two different runs: a graphite wire and a tungsten carbide wire having external shapes identical to the internal shape of a typical bonding capillary, tapering from a 1.2 millimeter diameter at the distal end to a 0.04 millimeter diameter at the proximal end. The cathode was a nickel cylinder about 60 mm in diameter surrounding the cathode. The electrodes were placed in the electrophoretic cell and a direct electrical current having a current density of about 1.0 mA/cm 2 was run between them for about 60 seconds, resulting in the deposition of a 1 millimeter thick deposit. The density of the deposited green bodies was about 70% of theoretical. The green body on the tungsten carbide cathode was removed, and the green bodies were sintered in air at 1550° C. for about 1.5 hours, yielding alumina capillaries with densities of 99% of theoretical and microhardness of 2500 kg/cm 2 .
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
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A method of electrophoretic deposition of a ceramic green body. A ceramic powder is optionally washed with a polar solvent such as deionized water, dried, and suspended in a polar organic solvent in a proportion of at least 20% by weight. A positive surface charge is imposed on the suspended particles by conventional means such as ball milling or ultrasonic treatment. A green body is deposited on a cathode by passing a direct electric current of constant current density through the suspension. The density of the green body generally is at least 70% of theoretical. The density of the fired body generally is at least 98% of theoretical. A layered green body may be deposited by using several suspensions of differing global ceramic composition and depositing each microlayer in a different suspension.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 12/283,060, entitled “Closed Loop Scroll Expander,” filed 8 Sep. 2008, the specification of which is hereby fully incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention generally relates to the methods and devices for high efficient power conversion by means of an externally heated closed loop regenerative heat engine which utilizes high pressure fluid, preferably carbon dioxide, through at least one scroll expander for the co-generation of shaft power, fluid power or refrigeration.
Currently the state of the art for engines are dominated by internal combustion engines based upon open-loop Otto cycle, Diesel cycle, or Brayton thermodynamic power cycles. Engines based upon these cycles have proven to be sufficiently efficient for many applications and the current state of the art including the benefits and detriments of the various types of engines is discussed in light of the present invention and the objectives of the present invention.
Otto Cycle and Diesel Cycle engines are used primarily for application in automobile, airplanes and other low cost applications (lawn mowers, pumps, etc. . . . ). These types of engines (two and four stroke engines) are efficient, lightweight, and fairly inexpensive to manufacture. Generally, in the last eighty years there has been much more focus in improving the designs and efficiencies for these types of engines by the various industries needing a cheap efficient means for converting power. There are significant limitations associated with using these types of internal combustion engines, including: a efficiencies of approximately 20% to 30%; a limited type of fuel associated with each type of engine; serious vibration and noise associated with cams, camshafts and piston rods; power density limitations; significant green house and carbon fuel emission associated with internal combustion engines; and limitations associated with operations of an internal combustion engine at limited air density environments (Brayton cycle turbines have this limitation as well).
In an internal combustion engine, the working fluid is primarily air. Heat through combustion is created by injecting and burning fuel with the working fluid at the proper location and at the proper time in the engine's cycle. This enables the working fluid to be expanded, which in part, produces work. While these engines are well understood and well developed, it is also known that these engines produce much less power than their theoretical limits due to the limitations association with the friction, heat loss and the timing associated with the combustion of the fuel and air mixture within the cylinder of an engine block.
These limitations can also limit the ability to control the quality of combustion and the range of air to fuel mixtures that can be ignited. The level of power available from these types of engines (Otto and Diesel cycle engines) is proportional to the mass flow of air passing through the engine itself. It is well known that these engines decrease delivered power as the atmospheric density of air decreases with altitude and the air temperature increases because the net mass flow of air available to the engine decreases.
In many applications, engines must operate in an environment with reduced atmospheric density. There is a decrease of power availability due to atmospheric density that is noted by the prior art and addressed in U.S. Pat. No. 7,284,363 which discloses a means for power generation for airborne vehicles operating at an altitude of 50,000 feet (above sea level). The various descriptions, in the '363, for closed loop engines converting power are limited to generic claims utilizing a Brayton or Rankine cycle type engine. The description of the working fluid expansion in the closed loop is done by means of a turbine, in both the Brayton and Rankine cycle mode of operation.
The present invention provides an engine that is capable of operating in a variety of thermodynamic cycle modes, including; Rankine, Brayton, or a supercritical cycle similar to U.S. Pat. No. 3,237,403 discussed below. The mode of operation is dependent on several factors, including: the environment in which the engine is operating; the type of working fluid used in the engine; the type of heat source utilized; and manipulation of the working fluid's temperature and pressure. The present invention takes advantage of the close loop system and is not limited to applications less than 50,000 feet. Additionally, the present invention provides a means for accomplishing power conversion in a small lightweight package with a high power density that can be utilized in numerous environments.
It is one objective of the present invention to be able to operate as a closed loop Rankine thermodynamic cycle for maximum efficiency and, depending on the conditions in which the engine is operating and the type of heat source used by the engine, be able to operate in other thermodynamic modes, like a Brayton cycle. Heat supplied to the working fluid is provided external to the engine and is transferred to the working fluid through means of a heat exchanger, such as an evaporator or boiler, thereby eliminating inefficiencies associated with integrating heat addition within the engine.
Generally the heat source will be something that is created through combustion of fossil fuels. External combustion or heat addition is an excellent means for increasing the efficiency of power generation without compromising the method of the heat addition. External combustion also greatly reduces the amount and type of green house gasses and pollution emitted by the engine. One objective of the present invention is to provide an engine that is able to use a variety of fuels or heat sources.
There are several externally heated engines in the prior art that are based upon the Stirling, and Ericsson thermodynamic power cycles. These examples in the prior art follow both open-loop and closed-loop thermodynamic cycle. There are also a number of mechanical and fluidic embodiments of these cycles in the prior art. From a theoretical stand point both the Stirling and Ericsson cycles potentially achieve efficiency near the absolute limit, defined by the efficiency of a Carnot cycle; however, in actual practice these cycles require isothermal compression and expansion of the working fluid. The physical means for achieving an isothermal process in compression and expansion is bulky, involves friction losses, and is limited by the power rate that can be achieved with heat exchangers. This has proven to make these types of heat engines heavy for the power they produce and do not achieve their desired theoretical efficiency.
For example, U.S. Pat. No. 7,124,585 discloses a scroll type expander having an integrated heating surface for the exchange of thermal energy to work output as a means for power conversion in this Stirling cycle type engine. This particular invention, besides having the limitation described above, has limitations associated with capturing or exchanging thermal energy integrated with an engine bloc of the system. In creating this type of engine, which has high theoretical efficiency, there is in reality several impracticalities for producing a small, lightweight, high power engine as described in the present invention, such as size and power output limitations.
In the present invention, the heat source is provided independent of the engine block or work output means and therefore provides more flexibility for the design and power output of the engine. Additionally by divorcing the heat generation from the engine block or power producing portion of the engine, heat sources that use carbon fuel consumption can be greatly enhanced with respect to the efficiency associated with complete combustion, heat transfer of combusted fuels, increase in the type of fuel consumed and a cleaner more easily managed fuel exhaust. It is one of the objectives of the present invention to provide an engine that is flexible with respect to the types of fuels that will be used for combustion or the type of heat source used on a working fluid in the closed loop. Currently, governmental and societal demands have been trending toward a need for an engine that is flexible with respect to the type of fuel consumed or used by engines.
In one embodiment of the present invention, the engine operates using the well proven and understood Rankine cycle. By taking advantage of the phase change in the closed loop, its efficiency is comparable to that achievable by Stirling and Ericsson cycle engines, but its power capability is far higher because it is not limited by isothermal compression and expansion. A good description of the power efficiency associated with the present invention is found in U.S. Pat. No. 3,237,403 issued to Feher in 1966 which discloses a device and method for using a supercritical fluid in a heat engine. The patent discloses the benefits associated with an external engine operating in a Rankine cycle. The description of the closed loop system anticipates a turbine or possibly a piston engine for expanding the high temperature high pressure working fluid (Col. 2, line 2-5). The patent, while describing the benefits of using a supercritical working fluid at a low cycle pressure substantially above critical pressure and a temperature below critical temperature, still lacks detail on how to effectively accomplish this process for a high pressure high temperature working fluid in a relatively small, lightweight package. The means for expanding or the method for expanding the working fluid in the claims are not disclosed in any detail, other than anticipation or use of a turbine.
In addition to a generic description of the process and the benefits associated with operating an engine at prescribed temperatures and pressures, the '403 concedes the “various mechanical components of the system are quite conventional in type but the components must be specially designed and built to operate properly under special conditions such as pressure, pressure ratio, high density of fluid passing through the turbine, and temperature and pressure limits in the regenerator, evaporator, condenser, etc.” The present invention addresses these limitations and actually describes in detail an engine that can operate in the mode described by the '403 as well as parameters beyond the scope of the '403.
In the detailed descriptions and claims of the '403, there was very little detail provided for the type of engine that was to be used in the application of the '403 patent. With the exception of calling for a “turbine”, the prior art relating to this type of engine concept do not address the means for power conversion addressed by the present invention.
In a Rankine cycle, as in one embodiment of the present invention, the engine's working fluid changes phase from liquid phase to gaseous phase after heating of the working fluid and from a gaseous phase to a liquid phase with the removal of heat. In a Brayton cycle the working fluid does not change phase. Its working fluid remains a gas or super-critical fluid throughout the cycle. For working fluids like air, Helium, or Nitrogen this lack of phase change is appropriate since the pressures and temperatures required to enable a phase change are impractical.
The present invention is able to take advantage of a working fluid that undergoes a phase change in a closed loop portion of the engine. In a Rankine cycle the working fluid is cooled to a liquid phase before a pump or means of pressurizing is used to increase its pressure prior to heating of the working fluid. The expansion of the working fluid in this type of system provides for a much more efficient thermodynamic cycle than Otto or Diesel cycle engines and most Brayton thermodynamic power cycles.
As noted in the prior art, the work to compress a liquid is far less than the work required to compress a gas or super-fluid. The gains associated with less work input to compress the fluid will result in more net power; therefore, reducing the work required to pump the working fluid to the cycle's high pressure increases the net power produced by the engine. For this reason, Rankine cycle engines tend to be more efficient than Brayton cycle engines.
One objective of the present invention is to provide a closed loop operating system in which the working fluid in a low temperature and low pressure portion of the loop can either be a liquid (phase change—Rankine cycle), vapor (no phase change—Brayton cycle) or a supersaturated high density fluid. The ability to operate an engine in various thermodynamic cycles is a tremendous advantage in applications for which the engine can operate. Advantages for operating in different thermodynamic modes include; various working environment in which the engine can operate, various working fluids can be utilized with little or no alterations of the basic design, and various heating sources can be utilized to heat the working fluid. These advantages in the present invention are not found in the prior art and provide for a flexible operating engine for numerous applications.
The selection of working fluids has some but very little impact on the theoretical potential of efficiency for the various thermodynamic cycles in which the engine operates, and primarily the operating temperatures and pressures of the cycle control this feature. Many types of working fluids have been used in Rankine cycle type engines in the past, including; water, nitrogen, carbon dioxide (CO 2 , propane, and various other organics. The working fluid to be used in a closed loop thermodynamic engine with an external heat source will depend on the range in which the heat source is able to produce heat and a heat sink source of a condenser in the closed loop. In the present invention, the engine is able to operate using various types of working fluids and the choice of the fluid would be dictated by the working environment in which the engine operates or the type of heat source to be used.
The selection of a working fluid is used to address the practical needs to transfer heat into the engine and to handle the working fluid as it changes phase. The present invention engine in one embodiment uses carbon dioxide (CO 2 ) as its working fluid due to its stable and non-reactive characteristic to very high temperature and remains a liquid to a very low temperature. This feature of CO 2 provides the potential for very high thermodynamic efficiency. There are practical challenges to using CO 2 as a working fluid because of its high critical pressure, yet relatively low critical temperature. Many of the features of the present invention address this particular technical challenge. The present invention also takes advantage of CO 2 thermodynamic properties, independent of its function as a working fluid for the Rankine cycle, for co-generation of refrigerant power and as a hydraulic power media for transferring mechanical power to various applications.
By using an external combustion process the in-efficiencies from integrating heat addition within the engine are eliminated. It allows the heat to be added to the cycle in a manner that does not compromise either the function of the engine or the efficiency and quality of the heat being provided. If the source of heat to the engine comes from the combustion of fuel and air, the control of the combustion can be optimized to maximize the heat provided and does not have to be constrained to the needs of the engine or its thermodynamic system. For example, to extract power from the engine, the pressure of the working fluid usually has to be maximized. For extracting heat from combustion, the pressure of the fuel and air mixture is not as critical and often not desired to be too high.
The external heat addition of the invention allows the needs of the power cycle to be addressed in design, and remain independent for the needs of heat addition. The mass flow of working fluid in the engine of this invention is also independent of the external environment and independent of the external heat addition. This means that power density of the engine can be increased by increasing the mass flow of working fluid through the engine. The fact that the working fluid of the thermodynamic cycle of the invention engine follows a closed-loop allows a separation of the power means of the engine from the heat addition means for the engine. It also allows the tailoring of the engine's working fluid to maximize power density and other important design considerations not possible if the working fluid is restricted to air in the engine's environment. One simple benefit of this arrangement is that the available power from the engine is not strongly dependent upon the density of the air of its environment. The power available from the invention engine is only dependent upon air density to the extent the external heating is dependent upon air density.
Most if not all of the prior art that takes advantage of an external heat source applied to a closed loop system describes expansion of the high pressure working fluid through a turbine type device. Turbines are an excellent means for converting thermal energy into mechanical energy with only a couple limitations. Turbines condition the flow of the working fluid by converting pressure into flow velocity to convert momentum into useful work. This requires the turbine to operate at high rotational velocity to achieve desired efficiencies of energy conversion. This results in the drive shaft, connected to the turbine, to also have a high rotational speed. A transmission device is required to make the shaft speed of the turbine useful for various applications. The present invention is a positive displacement device and converts pressure into work by direct expansion of pockets or discrete volumes of working fluid. The expansion of discrete volumes of working fluid within one or more scroll expanders enables a shaft output to operate more efficiently over a wide range of rotational velocities. By providing a means for obtaining a range of rotational speeds without losing efficiency provides a user with a wide variety of outputs or speed conditioning for useful applications. For example, rotational speeds needed for a generator, hydraulic pump or motor can be easily produced from the same scroll expander with little or no modification to the closed loop system.
Another objective of the present invention is to provide a means for converting high pressure working fluid into useful work in a small, lightweight package. A turbine is designed to concentrate the high pressure working fluid near or at the external lines of the turbine casing. The center portion of the turbine is occupied with the rotational element of the turbine itself, including a shaft, bearings, and seals. With high pressure fluid flow at the outer portions of the turbine casing, additional weight is necessary for maintaining the turbines integrity. The present invention is able to minimize the effects of high pressure working fluids loading a casing or engine block in which the scroll expander is placed. The scroll expander receives the high pressure working fluid at the center of the scroll expander with expansion of the working fluid decreasing as the working fluid travels through the scroll expander. The periphery of the casing or engine block is presented with a relatively lower pressure working fluid and therefore less weight is needed to maintain the integrity of the closed loop. This center out pressure reduction in a scroll expander of the working fluid results in a lighter and more compact thermal expansion device or engine block.
BRIEF SUMMARY OF THE INVENTION
The present invention claims a high efficiency engine capable of operating in a variety of thermodynamic modes, including a Rankine, Brayton, or supercritical cycle. The engine is comprised of a closed circulating system containing a working fluid, the system including: means to raise the pressure of said working fluid from a low cycle pressure to a high cycle pressure; means to add heat to said fluid substantially at said high cycle pressure to raise it to its high cycle temperature substantially above its critical temperature; means to expand said fluid by use of at least one scroll expander to do useful work; means to cool said fluid substantially at said low cycle pressure to a low cycle temperature; and said means to raise the pressure of said working fluid being provided from the useful work of said at least one scroll expander. Additional efficiency is captured using means to regeneratively transfer a portion of the working fluid's heat to the pressurized fluid as one means to cool said fluid.
The temperature and pressure of the working fluid can vary depending on several factors producing a very flexible operating system for use in a wide variety of application using a variety of working fluids and heating sources. To achieve a Rankine cycle mode of operation the means to cool said fluid at said low cycle pressure reduces the temperature of said fluid substantially below its critical temperature to render it completely liquid for entrainment by said pressurizing means. For a Brayton cycle mode the working fluid at said low cycle temperature is at or above the critical temperature of said working fluid. And for a supercritical mode of operation the low cycle pressure in said system is substantially above the critical pressure of said working fluid and said low cycle temperature is below critical temperature of the working fluid. The same engine is capable of operating in various thermodynamic modes with little or no changes to the system components.
The engine's operating environment, heat source and choice of working fluid will influence the mode of operation for the engine. The choice of working fluid will depend upon several factors including the type of heat source, the working environment in which the engine operates, and the compatibility of the engine components. In the description provided below, CO 2 as the working fluid is provided since this working fluid is readily available, operates over a fairly wide range of working environments, is non-reactive and is compatible with most all types of materials.
In the preferred embodiment, a pair of scroll expanders connected by a common shaft is used for a low weight, small package device that is able to produce a variety of power conversion means. In the preferred embodiment, the orbital shaft's rotations provide the power to operate at least one variable displacement pump. By using a variable displacement pump as a means for converting mechanical energy to hydraulic or fluid energy, the working fluid operating pressure is easier to maintain and a wider variety of energy outputs can be realized.
High pressure fluid energy can be used for mechanical drive means for propulsion such as; wheels, or tracks for land vehicles, propeller screws, pumps, jets, or paddles for marine vehicles, or rotors, fans, or propellers for both heavier than air and lighter than aircraft.
Other forms of power transfer including the conversion of high pressure working fluid, in a liquid state, into mechanical or hydraulic outputs such as actuators, motors and electrical generation with re-introduction of the working fluid as return flow back into the engine cycle. Pressurizing a secondary fluid to minimize penetration of an engine block assembly can provide mechanical means for power transfer into a variety of applications including hydraulic motors, generators or direct motive applications. Additionally, power conversion of the high pressure working fluid can also be provided for co-generation of high-pressure liquid for a refrigerant cycle, with return of warm low pressure working fluid back into the engine cycle. Finally a direct shaft power pick off of the orbital shaft rotation can be obtained with torque being applied for various applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 a schematic of an engine with an external heat source being applied to a closed loop system containing; a balanced pair of scroll expanders, a set of variable displacement pumps associated with the each expander, several means for exploiting either the high pressure fluid discharged by the variable displacement pumps or direct linkage to a rotary shaft of the scroll expanders, and other supporting components.
FIG. 2 a is a temperature-entropy diagram illustrating a process in which the engine will operate in a thermodynamic cycle similar to a Rankine cycle.
FIG. 2 b is a temperature-entropy diagram illustrating the process in which the engine will operate in a thermodynamic cycle similar to a Brayton cycle.
FIG. 2 c is a temperature-entropy diagram illustrating the process in which the engine will operate in a thermodynamic cycle in which the working fluid's pressure is above critical pressure throughout the closed loop even at a low cycle pressure and the working fluid's temperature is below critical temperature at a low temperature cycle of the closed loop.
FIG. 3 is a cross-sectional side view of a scroll expander showing a fixed scroll plate and an orbital scroll plate and integration of the two scroll plates by a set of spiral bands attached to each plate.
FIGS. 4-8 are cross-sectional end view of the first and second scroll expander. The end views of the first and second scroll expanders are similar and the numbering within the detailed description of the parts covers both scroll expanders. The view shows a fixed scroll plate with internals of the fixed and orbital scroll plate spiral bands integrated in such a manner as to display discrete volumes or pockets within the integrated plates. The various views from FIG. 4 through 8 show various positions of the fixed and orbital spiral bands and a volume of working fluid passing through said expander through one orbital rotation with FIG. 4 being zero degrees, FIG. 5 being 90 degrees orbital rotation from FIG. 4 , FIG. 6 being 90 degrees orbital rotation from FIG. 5 , FIG. 7 being 90 degrees orbital rotation from FIG. 6 , and FIG. 8 back to zero degrees or 90 degrees orbital rotation from FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the invention will now be described. The following descriptions provide specific details for a thorough understanding and enabling description of these embodiments. It should be noted, however, that the above “Background” describes technologies that may enable aspects and embodiments of the invention. One skilled in the relevant arts will understand, however, that the invention may be practiced without many of these details. Additionally, some well-known structures or functions may not be shown or described in detail, so as to avoid unnecessarily obscuring the relevant description of the various aspects and embodiments of the invention.
The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized herein; however, any terminology intended to be interpreted in any restricted manner will be overly and specifically defined as such in this Detailed Description section.
FIG. 1 is a schematic of a power conversion system or an engine with energy from an external heat source 11 being converted in a closed loop assembly to a desirable form of energy. To describe this process, a narrative of the working fluid in the closed loop is explained with additional detail of the various parts of the system being supplied with respect to the processing of the working fluid around the closed loop. In one embodiment, a working fluid, most likely carbon dioxide (CO 2 ), will operate at pressures and temperatures generally above supercritical pressure and mostly above supercritical temperature however system pressures and temperatures can be much more expansive—falling below critical temperature and pressure—to operate the engine and will depend upon several factors including; an operating environment in which the system is located, source or type of external heat applied to the closed loop, heat sink temperatures and other factors associated with the various components of the system and will be discussed as alternative embodiments of the present invention.
To start the narrative, from FIG. 1 and FIG. 2 a point A being at the outlet of an evaporator 60 where the working fluid is at its highest temperature and pressure. Upon leaving the evaporator, the working fluid is directed to an engine assembly 22 which contains most of the necessary components for power conversion. At this point in the closed loop, the working fluid is at its highest temperature and pressure. FIGS. 2 a , 2 b and 2 c are temperature-entropy diagrams that correspond to the temperature and entropy of the working fluid as the working fluid is processed through the closed loop. The three cycles, Rankine, Brayton, and supercritical, represent various modes of operation the present invention is capable of operating in.
The temperature for highest overall efficiency should be as high as possible and only constrained by the temperature of the heat source, integrity or technical aspects of the system, and the working fluid selected. In the preferred embodiment, the working fluid will have characteristics the same as or similar to carbon dioxide, CO 2 , for example with CO2 the temperature range will be as high as 1800K. The pressure of the working fluid is selected by design consideration of the regenerative heat exchanger, the desired low pressure of the cycle, and the level of expansion intended for power extraction. Operating pressures will be above 200 bar. FIG. 2 a depicts a generic temperature entropy diagram of a closed loop operating system. Point A depicts the working fluid at its highest temperature and highest pressure prior to entry into the engine block assembly 22 . FIG. 2 a is a depiction of a Rankine thermodynamic cycle and as discussed earlier, a very efficient means for converting thermal power to work out. The working fluid is cooled to a liquid for efficient pressurizing later in the process.
In the preferred embodiment, the assembly 22 represents a type of engine block in which the high pressure and temperature of the working fluid is more easily maintained with fewer opportunities for loss of working fluid from numerous joints, gaskets, and other components less able to handle the high pressure and temperature of the supercritical working fluid. By directing high pressure working fluid through penetrations into and out of the engine assembly, the integrity of the closed loop is more easily maintained and therefore smaller and more compact. The engine assembly is a preferred embodiment of the system but in no way limits the scope of the claims and is only meant to describe one embodiment.
As the high pressure and temperature working fluid enters the engine assembly, the working fluid enters a first scroll expander 30 through an inlet line 32 in the assembly. The working fluid is directed to a first scroll expander intake chamber 32 a , see FIGS. 3 and 4 .
The operation of the scroll expander is similar to the description provided in U.S. Pat. No. 801,182 originally proposed by Léon Creux in 1905. The first scroll expander 30 has a fixed 34 and orbital 35 scroll plate that are integrated in such a manner as to create isolated chambers of ever increasing volume from the intake chamber 32 a where the high pressure working fluid first enters the scroll expander. The fixed scroll plate 34 has a spiral band 85 axially mounted to the face of the plate projecting in toward the orbiting scroll plate, the spiral band is shaped as an involute curve on the plate face as can be seen on FIG. 4 . The orbiting scroll plate 35 has a spiral band 86 axially mounted to its face and the spiral is configured counter or reversed from the spiral band 85 affixed to the fixed scroll plate 34 such that when the orbiting scroll plate 35 and fixed scroll plate 34 are engaged or integrated, the spiral bands of the fixed and orbiting scroll plate contact each other at several points along the length of the bands creating two crescent shaped zones, like zones 83 a and 83 b shown on FIG. 4 within the pair of spiral bands. The number of contact points between the orbital scroll 35 and the fixed scroll 34 are a function of the length of the spiral band and the size of the scroll expander. At the periphery of the first scroll expander fixed plate is an outlet 33 where lower pressure working fluid leaves the first scroll expander. The working fluid at this point still retains significant thermal energy with the pressure reduction of the working fluid being a function the spiral band lengths and width of said spiral bands. The result of integrating the fixed and orbital scroll plates is a scroll expander 30 .
The expansion of the working fluid within the expander causes the orbital plate to orbit or move in a circular path, refer thereto FIG. 4 through 8 . When the high pressure fluid is introduced into the scroll expander as depicted by the darker area near the center in FIG. 4 , the fluid occupies the high pressure intake chamber 32 a and surrounds the innermost portions of the spiral bands 85 and 86 of the orbital and fixed scroll plates, with the contact points between the fixed and orbital spiral bands providing a means for separating and isolating the incoming fluid from the radially outward moving crescent shaped zones 83 a and 83 b as seen in FIG. 4 through 8 . It should be noted that one of the benefits of this design is the elimination of valving and timing mechanisms necessary in Otto and Diesel cycle engines. The working fluid is continuously being cycled through the closed loop and the engine requires no valving and does not require specialized timing for combustion of the external heat source or pressurization.
In FIG. 4 said orbital plate is at 0 degrees of the circular orbit of said orbital plate, the high pressure fluid contacts the inner wall of the crescent shaped volume of the orbital plate, the high pressure working fluid moves the orbital plate out and in a radial path. As the working fluid moves the orbital plate in an orbital path, the crescent shaped volumes increase in size allowing the working fluid to expand, see FIG. 4 through FIG. 8 depicting one crescent shaped volume during orbital rotation from zero degrees through 360 degrees.
The orbital path of the orbital scroll plate is accomplished by the integration of the spiral bands within the scroll expander and the limited rotational movement of the orbital scroll plate due a set of thrust bearings 39 located on the opposite side of the spiral bands of the orbital scroll plate, see FIG. 3 . In one embodiment, the thrust bearings will be a fixed bearing plate 39 a attached to the engine assembly and another bearing plate 39 b attached to the orbital plate with ball bearings 39 c situated between the bearing plates allowing limited movement for the orbital plate of the first scroll expander.
The technology associated with a thrust bearing providing means for rotation and sealing protection with respect to the orbital scroll plate and fixed plate is well known to those skilled in the art. Many embodiments of various systems are found in the prior art, especially scroll technology associated with compressors.
As the working fluid is expanded through the first scroll expander the working fluid's pressure will decrease with a decrease in temperature. This expansion is the conversion of the thermal energy into the mechanical energy of the scroll expander. The efficiency and power output of the scroll expander are not only a function of the operating pressure but a function of the size and depth of the spiral bands of the fixed and orbital scroll plates. The ability of the scroll expander to convert thermal energy into working energy is dependent on a number of factors. The most easily manipulated factor is the length and width of the integrated spiral bands of the orbital and fixed scroll plates. The longer the spiral band or the deeper the width of the spiral band, the more power is converted from thermal energy to orbital movement of the orbital plate.
There are several means by which the scroll expander is able to convert thermal energy into some other form of work. In one embodiment, the fixed scroll plate 34 has two sides with one side having the spiral band 85 described above and the other side being attached to the engine assembly 22 . The orbital scroll plate has two sides with one side having the spiral band 86 described above and the other side of the orbital plate being attached to one end of an orbital shaft 91 contained within the engine assembly 22 . In one embodiment of the invention, at least one variable displacement pump 31 is connected to the orbital shaft 91 .
In the preferred embodiment of the present invention as depicted in FIG. 1 , a swash plate variable displacement pump is turned or rotated from the orbital motion of the orbital shaft attached to the orbital plate of the first scroll expander. A swash plate variable displacement pump is not a novel concept and is well known to those skilled in the art of pumps and hydraulic systems. The pump is integrated with the first scroll expander 30 , by means of the orbital shaft 91 , with the orbital rotation of the orbital plate causing the rotation of the shaft. In one embodiment, the swash plate variable displacement pump increases the pressure of the working fluid (Note: this is the same working fluid that enters the scroll expander described above but at a later stage in the closed loop and will be discussed below) and the high pressure working fluid at the pump outlet can be converted into a variety of other uses, such as being used in a liquid variable displacement motor or generator.
Variable displacement pumps, or in the preferred embodiment swash plate pumps, are used because they are efficient, have variable displacement, operate efficiently at different speeds, and have high power density. Typically, swash plate pumps are designed to deliver a constant output pressure. The variable displacement pumps will automatically adjust their displacement as required to maintain outlet pressure regardless of the speed of the scroll expander or feed pressure of the working fluid at the pump inlet.
By using a variable displacement pump, the engine is able to produce constant or reactive work output while maintaining a high level of efficiency through a broad spectrum of shaft speeds. Turbines engines are limited in that the turbine is most efficient when the turbine is operating at high speeds with tremendous pressure differential. A turbine is not capable of operating at a slower speed without significant efficiency degradation. Piston engines are capable of operating in various speeds but lack the ability to operate efficiently at other than optimum operating speeds.
In the first scroll expander 30 , when the working fluid is expanded during the orbital rotation of the fixed and orbital plates the fluid reaches the periphery of the scroll expander and exits through an annulus or outlet 33 located within the fixed plate wall to an outlet line 33 a . The working fluid still retains a significant amount of thermal energy and is able to be expanded further. In one embodiment of the invention, to accomplish further expansion, the first scroll expander outlet line 33 a directs the working fluid to an inlet 42 of a second scroll expander 40 .
The second scroll expander 40 is similar to the first scroll expander with the orbital plate 45 of the second scroll expander connected to the same orbital shaft 91 of the first scroll expander. This connection of the second and first scroll expanders allows for a more efficient machine. The expansion of the working fluid through the second scroll expander is similar to the first scroll expander. The size, depth and shape of the spiral bands of the second scroll expander can be manipulated to enhance the output between the first and second scroll expanders.
As the working fluid enters an inlet chamber 42 a , of the second scroll expander 40 . The second scroll expander 40 has a fixed 44 and orbital 45 scroll plates that are integrated in such a manner as to create isolated chambers of ever increasing volume from the intake chamber 42 a where the high pressure working fluid first enters the scroll expander. FIG. 4 through FIG. 8 depicting an orbital rotation of the first scroll expander 30 is the same as the second scroll expander and the only difference would be the part numbers associated with the components. The fixed scroll plate 44 has a spiral band 87 axially mounted to the face of the plate projecting in toward the orbiting scroll plate, the spiral band is shaped as an involute curve on the plate face. The orbiting scroll plate 45 has a spiral band 88 axially mounted to its face and the spiral is configured counter or reversed from the spiral band 87 affixed to the fixed scroll plate 44 such that when the orbiting scroll plate 45 and fixed scroll plate 44 are engaged, the spiral bands of the fixed and orbiting scroll plate contact each other at several points along the length of the bands creating several crescent shaped zones, like zones 84 a and 84 b within the pair of spiral bands. The number of contact points between the orbital scroll 45 and the fixed scroll 44 are a function of the length of the spiral band and the size of the scroll expander. At the periphery of the second scroll expander fixed plate is an outlet 43 where the now lower pressure working fluid leaves the second scroll expander. The working fluid at this point is considered exhaust fluid.
In one embodiment as depicted in FIG. 1 , an additional variable displacement pump 41 is connected to the orbital shaft in balance with a first variable displacement pump 31 . The same configuration is used for both variable displacement pumps—again a swash plate variable displacement pump is the used in the preferred embodiment with the working fluid being pressurized and the working fluid at the outlet 38 and 48 of the first and second variable displacement pumps being directed to one or more means for converting said high pressure working fluid to some other form of energy.
After the working fluid has been expanded for a second time through the second scroll expander 40 , the working fluid or exhaust fluid still retains significant amounts of thermal energy, and from FIG. 2 a , the working fluid is now at B on the graph having a significant amount of work taken from the expansion of the working fluid in the form of orbital shaft rotations. The high temperature of the exhaust fluid, at point B, is transferred to the working fluid at point E that is being directed to the evaporator prior from the outlet of the variable displacement pumps. This transfer of thermal energy is accomplished using a regenerative heat exchanger 52 . The regenerative heat exchanger 52 can be integrated within the engine assembly or placed outside the assembly—the function of the device remains the same. The benefits for using a regenerative heat exchanger are detailed in U.S. Pat. No. 3,237,403. In one embodiment, the critical pressure of the exhaust fluid and the high pressure low temperature working fluid that enter the regenerative heat exchanger are above critical pressure for optimum efficiency.
It should be noted that the first and second scroll expander are not limited to a fixed and orbital plate, instead recent designs, such as U.S. Pat. No. 4,927,339, issued to Riffe et al., have incorporated relative orbital movement between two plates having spiral bands that when integrated form discrete volumes of space like the fixed and orbital face plates described above. This relative orbital movement requires both plates to orbit or move in an orbital path with respect to each other. The discrete volume of space created by the integrated plates increase as the space moves radially toward the periphery like the fixed and orbital face plates but both plates are moving. The same effect is obtained and the present invention is meant to incorporate a scroll expander with either method of orbital rotation between two plates.
In the description of the present invention reference is made to a fixed and orbital face plate. A more generic and applicable phrasing for a scroll expander would include a pair of integrated face plates that have a relative orbital motion between a set of spiral bands attached to said face plates. The spiral bands are integrated and form at least one discrete volume of space between connecting points of the spiral bands of the two face plates. When there is relative orbital movement between the two face plates the discrete volume is radially transferred to the periphery and the volume of said discrete space increases toward the periphery. The description of the present invention is not meant to be limited with respect to the type of scroll expander that is employed and the use of the scroll expander is meant to encompass all types and varieties of scroll expanders.
When operating as a Rankine cycle engine, the hot gaseous exhaust fluid needs to be converted to a liquid prior to pressurizing the fluid and entry into the evaporator 61 . By passing the hot gaseous exhaust fluid through the regenerator 52 the engine increases its efficiency greatly. The working fluid passing on the other side of the regenerator from the exhaust side absorbs the thermal energy and goes from liquid state, point E to point F on FIG. 2 , and approaches partial phase change prior to entering the evaporator where the liquid is completely converted to a gaseous phase, point A.
When the exhaust fluid exits the regenerative heat exchanger the working fluid is at a lower pressure but still in a gaseous phase, to complete the phase change to a liquid, the working fluid, now at point C on FIG. 2 , is passed through a condenser 95 that will typically be outside the engine assembly shown in FIG. 1 . The type of condenser used in the present invention will depend on the operating environment in which the engine is to be used. The prior art is replete with description of condensers and this application is not intended to capture innovation associated with the condenser. In the preferred embodiment and the most efficient operating mode of the engine, the working fluid is converted from a gaseous phase to a liquid phase in the condenser at this point the working fluid is at point D on FIG. 2 .
In one embodiment of the engine, after the working fluid exits the condenser, the working fluid is collected in a reservoir 23 prior to being pressurized by the first and second variable displacement pumps attached to the first and second scroll expanders 30 and 40 . The working fluid upon discharge from the variable displacement pumps is at point E on FIG. 2 .
By completing the phase change of the working fluid from gaseous phase to a liquid phase in the condenser, the work needed to increase the pressure of the working fluid prior to heat being added is significantly reduced as explained in U.S. Pat. No. 3,237,403 issued to Feher disclosing a closed loop supercritical regenerative heat engine and U.S. Pat. No. 7,284,363 issued to Kung, et al, disclosing a use for a closed loop supercritical regenerative heat engine in an aircraft above 50,000 feet.
In one embodiment of the invention, the working fluid once pressurized, point E on FIGS. 1 and 2 , is used as a cooling fluid for the moving parts of the first and second scroll expanders as depicted by a first engine housing cooler 36 and second engine housing cooler 46 . By acting as a cooling source for the scroll expanders, thrust bearings, and orbital shaft, the working fluid is able to capture additional heat energy potentially lost in the closed loop of the engine.
In one embodiment of the engine, as the working fluid exits the first and second engine housing coolers 36 and 46 , the working fluid is directed to a working fluid drive as depicted by the variable displacement motor 70 of FIG. 1 . In the preferred embodiment, the drive is a variable displacement hydraulic motor using high-pressure liquid CO 2 as its working fluid. The output of the orbital shaft rotations is translated into a high pressure fluid that is more easily transferred outside the engine assembly. Transfer of high pressure working fluid outside of the engine housing is easier in that fewer and small penetrations into the engine housing will reduce the likelihood of leaks and thereby maintain system pressure.
Another embodiment for accomplishing a similar power transfer as described above is to utilize a secondary working fluid that is pressurized by means of a variable displacement pump connected to the orbital shaft—similar to the description above using the working fluid. In this embodiment, the secondary working fluid is separate from the working fluid of the closed loop and pressurized by a variable displacement pump attached to the orbital shaft. The high pressure secondary working fluid would then pass out of the engine assembly and be used for capturing power in various forms such as an hydraulic motor or generator. The secondary working fluid is then returned to the engine assembly and pressurized again for reuse—a second closed loop. Pressurizing a secondary working fluid could be accomplished by connecting a variable displacement pump to the orbital shaft as described above. The working fluid of the first closed loop could be pressurized by one or more separate pumps attached to said orbital shaft. Flexibility in utilization of the rotating orbital shaft is one of the benefits of using a scroll expander since the rotational speed of the orbital shaft can be varied depending on the desired speed of rotation needed.
Experiments and studies have shown that the pressure of the working fluid of the closed loop will be above 200 atm. and probably much higher with the pressures in the pump and shaft compartment of the engine assembly above 75 atm. A pressure penetration in the engine assembly to obtain a direct rotational shaft output will likely have significant frictional losses as well as degrading the integrity of the closed loop working fluid pressure. Designing a system for a direct power transfer from the orbital shaft rotations is possible but requires significant engineering and additional moving parts to maintain a high efficiency output. Therefore power conversion by means of hydraulic power transfer is one of the preferred embodiments of the present engine.
It is also desirable for generating output shaft speed independent of the orbital shaft speed. The orbital shaft speed will want to vary with the power load demanded by a current application of a variable motor or generator. The output shaft speed is likely to be controlled by the application; for example, generator speed, or drive speed of a vehicle. By disconnecting the orbital shaft speed from the output shaft speed, greater flexibility in the design and application of the system is available. The same engine with little or no modifications to the closed loop system could be used for vehicle transport, electrical generations, hydraulic power or various other applications.
As described above, one embodiment of the present invention is to directly convert orbital shaft rotation to work out through a direct power pick off. Power pick-off of the orbital shaft has the limitation described several limitations described, primarily; inefficiencies associated with friction loss, moving parts requiring significant engineering and machining, larger penetrations of the engine assembly, and reduced integrity of the closed loop. This mode of operation is schematically shown on FIG. 1 by the block component 80 . The prior art is replete with technologies for converting rotating shaft speed into rotating shaft speed of vehicles, generators, pumps and the like. This mode is generally not preferred when the goal is to create a small lightweight high power density engine.
Another mode of operation for the engine is to use the high pressure output of the variable displacement pumps in a refrigeration cycle and returning warmed up expanded working fluid from said refrigeration cycle. This mode of operation is depicted in FIG. 1 by the block 90 . It should be noted that the output of the variable displacement pumps is directed to the refrigeration loop and the return line for the working fluid is connected to the output of the regenerative heat exchanger for the exhaust fluid. Operation of a refrigeration loop can be done in conjunction with the power conversion of the high pressure working fluid in a variable displacement motor or generator.
Another embodiment of the engine uses a power control valve 51 located on the outlet of the variable displacement pumps 31 and 41 . It should be noted that the orbital shaft could have one or more variable displacement pumps attached to the orbital shaft and the number and size of the variable displacement pumps depends upon the desired pump output. In the schematic shown, FIG. 1 , a configuration with two variable displacement pumps 31 and 41 pressurizing the working fluid prior to reheating in the regenerative heat exchanger 52 . The pumps, preferably swash plate variable displacement liquid pumps, are designed to produce a constant high pressure output despite load requirements from the one or more power outputs of the system. The pumps respond to a mass flow demand on the high-pressure side of the engine, as shown as point E of FIG. 2 . The speed of the scroll expanders are controlled by the mass flow of the working fluid delivered to the scroll expanders, via the evaporator, by a power control valve 51 . In this way the scroll expanders always operate near their optimal pressure and efficiency.
The power output of the engine varies with the speed of the scroll expanders which is controlled by the power control valve 51 and the level of heat being supplied to the evaporator 60 . Not only are swash plate variable displacement pumps used in the preferred embodiment because they are efficient and reliable, they are designed to always deliver the constant output pressure regardless of the demand on the system. They will automatically adjust their displacement as required to maintain this output pressure regardless of the speed of the orbital shaft 91 or feed pressure of the working fluid supplied by the working fluid reservoir 23 .
The engine depicted in FIG. 1 is not limited to cycles in which the working fluid undergoes phase change prior to pressurizing as shown in FIG. 2 a . The engine of the preferred embodiment is capable of operating in various thermodynamic modes, including; a Brayton cycle engine when the engine's operating environment raises the temperature on a heat sink side of the condenser preventing conversion of the working fluid to liquid phase. In a Brayton cycle mode of operation, see FIG. 2 b , expansion of the working fluid through the one or more scroll expanders is depicted from point A to point B. The exhaust working fluid supplies heat to the working fluid prior to the working fluid entering the evaporator 60 —the regenerator 52 depicted, by point B to point C for the exhaust and point E to point F for the preheating of the working fluid. Whatever cooling is accomplished by the condenser will take the working fluid from point C to point D—in the Brayton cycle the working fluid does not undergo phase change and the working fluid while more dense is still in a gaseous phase. The pumping of the low temperature working fluid into the evaporator will be less, efficient when the working fluid is in a gaseous or vapor phase, point D to point E, however the efficiency of utilizing an external heat source makes up for some of the inefficiencies associated with a lack of phase change prior to pressurization of the working fluid. Condensing the working fluid to a liquid is mostly a function of the environment in which the engine is operating or the type of condenser used in the closed loop.
Other modes of operation for the engine exist as well, including operation of the engine with the working fluid remaining above critical pressure throughout the closed loop cycle, as depicted in FIG. 2 c . After working fluid exits the evaporator 60 as depicted as point A FIG. 2 c , the one or more scroll expanders reduces the temperature and pressure of the working fluid to point B. The regenerator 52 converts the high temperature exhaust point B to a lower temperature and pressure point C. High pressure working fluid headed toward the evaporator absorbs the latent heat of the exhaust—depicted as point E to point F. When the working fluid is passed through the condenser 95 , point C to point D, the working fluid undergoes a phase change to a supercritical liquid. The pump pressurizes the working fluid, point D to point E. The pressure of the working fluid throughout the system is above critical pressure allowing for the most efficient means for operating the engine as described in U.S. Pat. No. 3,237,403.
Another feature of the present invention is the ability to use a variety of fuels or heat sources for raising the temperature of the working fluid prior to expansion. In one embodiment of the invention, the heat source is provided by the combustion of carbon fuels. In another embodiment of the engine, the heat source is provided by heated materials capable of retaining their energy over a significant period of time while supplying a high temperature heat source. Heated bricks or containers of molten salts or molten metal like Lithium, or Aluminum or mixtures or Lithium and Lithium hydride are possible. Other heat sources including solar collectors, geothermal, and electrical power sources are readily available with little or no alterations to the closed loop system.
It should be pointed out that the figures and description for the scroll expanders shows first and second scroll expander with the working fluid being processed by the expander in sequential order. Another embodiment of this engine include, two or more scroll expanders arranged such that the working fluid is processed in parallel instead of in sequence as depicted in FIG. 1 . Other scroll expander arrangements are not shown but it is the intent of the present invention to capture the use of at least one scroll expander in an external combustion closed loop system with the scroll expander work being used to pressurize the working fluid. In addition, the work output of the scroll expanders will be captured by use of at least one variable displacement pumps that are able to transfer mechanical energy into hydraulic or fluid energy for a variety of energy outputs.
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Apparatuses and methods related to an engine for converting heat into mechanical output using a working fluid in a closed circulating system are disclosed. In some embodiments, the engine includes a pump to pressurize the working fluid, a regenerative heat exchanger to transfer heat from a first portion of the working fluid to a second portion, a heating device to heat the working fluid, and a scroll expander to expand the working fluid and generate the mechanical output. Other embodiments may be described and claimed.
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[0001] This patent application claims the benefit of priority to U.S. Provisional Patent Application 61/092,868 filed on Aug. 29, 2008.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the invention relate to phase change memory materials and more particularly to GeAs telluride materials useful for phase change memory applications, for example, optical and electronic data storage.
[0004] 2. Technical Background
[0005] Conventional phase change memory devices utilize materials which can change between two phases having distinct properties. The materials, typically, can change from an amorphous phase to a crystalline phase, and the phases can have considerably different properties, for example, different resistivities, conductivities, and/or reflectivities.
[0006] Phase change from an amorphous phase to a crystalline phase can be achieved through heating the amorphous material to a temperature which promotes nucleation, crystal formation, and then crystallization. The phase change back to amorphous can be achieved by heating the crystalline phase above the melting temperature.
[0007] Chalcogenide materials, for example, Ge, Sb, and Te alloys are currently used in phase change memory applications such as for storing information in over writable disks.
[0008] Several phase change memory materials identified to date have been developed by workers at Matsushita/Panasonic and IBM. Representative materials include compositions on the GeTe—Sb 2 Te 3 join, particularly Ge 2 Sb 2 Te 5 (GST), and Au, In-doped Sb telluride (AIST). These materials can be cycled on a ˜10 ns time scale between a high conductivity, high reflectivity crystalline phase and a low conductivity, low reflectivity amorphous phase under laser heating or current pulses.
[0009] Although some conventional materials such as GST and AIST have good properties for non-volatile memory applications, it would be advantageous to have phase change memory materials that have faster phase transitions and/or longer write/rewrite potential.
SUMMARY
[0010] Embodiments of the invention are GeAsTe-based compositions for phase change memory applications that lie outside of the canonical GeSbTe system. Moreover, as certain GeAsTe compositions can be made into bulk glasses, the stability of the GeAsTe amorphous phase is likely to be greater than that of the GeSbTe analogues where bulk glass formation is not possible. This feature may result in an increased number of write/rewrite cycles without degradation of conductivity/reflectivity contrast as well as longer data retention.
[0011] One embodiment of the invention is an article comprising a crystallized thin film comprising a composition having at least one hexagonal phase, or a crystallizable composition capable of having at least one hexagonal phase in a crystallized form.
[0012] Another embodiment of the invention is a method comprising providing a thin film comprising a phase change memory amorphous material, and converting the phase change memory amorphous material to a hexagonal crystalline phase.
[0013] Yet another embodiment of the invention is a method comprising providing a thin film comprising a phase change memory material having a hexagonal crystalline phase, and converting the hexagonal crystalline phase to an amorphous phase.
[0014] Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the invention as described in the written description and claims hereof, as well as the appended drawings.
[0015] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed.
[0016] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s) of the invention and together with the description serve to explain the principles and operation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention can be understood from the following detailed description either alone or together with the accompanying drawing figures.
[0018] FIG. 1 is a composition diagram for GeAsTe materials.
[0019] FIG. 2 is a graph of reflectivity data for a material according to one embodiment.
[0020] FIG. 3 is a graph of reflectivity data for a material according to one embodiment.
[0021] FIG. 4 and FIG. 5 are graphs of X-ray diffraction data for conventional phase change memory materials.
[0022] FIG. 6 and FIG. 7 are graphs of X-ray diffraction data for phase change memory materials according to the present invention.
DETAILED DESCRIPTION
[0023] Reference will now be made in detail to various embodiments of the invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like features.
[0024] One embodiment of the invention is an article comprising a crystallized thin film comprising a composition having at least one hexagonal phase, or a crystallizable composition capable of having at least one hexagonal phase in a crystallized form.
[0025] The composition, according to some embodiments, comprises in atomic percent:
5 to 45 Ge; 5 to 40 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 45 to 65 Te.
[0029] The composition, according to some embodiments, comprises in atomic percent:
10 to 30 Ge; 15 to 30 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 50 to 60 Te.
[0033] The composition can further comprise Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof is 20 percent or less, in some embodiments. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof is 15 percent or less, in some embodiments.
[0034] According to one embodiment, the thin film is disposed on a substrate. The thin film can be deposited on a substrate, according to one embodiment. The substrate comprises a glass, a glass ceramic, a ceramic, a polymer, a metal, or combinations thereof, in some embodiments.
[0035] GeAsTe glasses and their crystalline analogues have the potential of being phase change materials characterized by a glassy state that can be more stable than that of conventional phase change materials such as GST and AIST. A wide range of GeAsTe glasses, according to the invention, can transform to a more reflective crystalline phase upon heating than the above described conventional materials. For glasses on the Te—GeAs 2 join, this phenomenon has been demonstrated for compositions containing from 45 to 65 atomic percent Te. Many of these materials, when crystallized, consist of at least two phases: either two crystalline phases or one crystalline phase plus a residual glass phase.
[0036] Glasses with compositions on the As 2 Te 3 —GeTe join, however, can be crystallized to a single phase and, as such, can exhibit maximum conductivity/reflectivity contrast between the glassy and crystalline state. Such glasses can be doped with constituents compatible with the crystalline phase, such as Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof without forming a second phase in the heated state.
[0000]
TABLE 1
GeAs 2 Te 4
Ge 2 As 2 Te 5
Ge 3 As 2 Te 6
GeAs 1.2 Sb 0.8 Te 4
GeAs 1.4 Sb 0.6 Te 4
GeAs 1.9 Bi 0.1 Te 4
Ge
14.3
22.2
27.3
14.3
14.3
14.3
As
28.6
22.2
18.2
17.1
20
27.1
Sb
—
—
—
11.4
8.57
—
Bi
—
—
—
—
—
1.43
Te
57.1
55.6
54.5
57.1
57.1
57.1
Si
Ga
In
P
[0000]
TABLE 2
Ge 0.9 Si 0.1 As 2 Te 4
Ge 0.9 Ga 0.05 P 0.05 As 2 Te 4
Ge 0.9 In 0.05 P 0.05 As 2 Te 4
Ge
13.21
13.21
13.21
As
28.57
28.57
28.57
Sb
—
—
—
Bi
—
—
—
Te
57.14
57.14
57.14
Si
1.07
—
—
Ga
—
0.54
—
In
—
—
0.54
P
—
0.54
0.54
[0037] Exemplary compositions, according to the invention, are shown in Table 1 and Table 2.
[0038] Another embodiment of the invention is a method comprising providing a thin film comprising a phase change memory amorphous material, and converting the phase change memory amorphous material to a hexagonal crystalline phase.
[0039] Phase change from an amorphous phase to a hexagonal crystalline phase can be achieved through heating the amorphous material to a temperature which promotes nucleation, crystal formation, and then crystallization.
[0040] Converting the phase change memory amorphous material to a hexagonal crystalline phase can comprise heating. Isothermal heating, for example, electrical heating using resistive and/or inductive heating; laser heating; or the like can be used to heat the thin film to induce phase change.
[0041] According to one embodiment, the phase change memory amorphous material comprises in atomic percent:
5 to 45 Ge; 5 to 40 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 45 to 65 Te.
[0045] The phase change memory amorphous material, according to some embodiments, comprises in atomic percent:
10 to 30 Ge; 15 to 30 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 50 to 60 Te.
[0049] The phase change memory amorphous material can further comprise Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof is 20 percent or less, in some embodiments. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof can be 15 percent or less.
[0050] Yet another embodiment of the invention is a method comprising providing a thin film comprising a phase change memory material having a hexagonal crystalline phase, and converting the hexagonal crystalline phase to an amorphous phase.
[0051] This phase change to the amorphous phase can be achieved by heating the crystalline phase above the melting temperature of the phase change memory material.
[0052] In some embodiments, converting the phase change memory material having the hexagonal crystalline phase to the amorphous phase comprises heating. Isothermal heating, for example, electrical heating using resistive and/or inductive heating; laser heating; or the like can be used to heat the thin film to induce phase change.
[0053] According to some embodiments, the phase change memory material comprises in atomic percent:
5 to 45 Ge; 5 to 40 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 45 to 65 Te.
[0057] The phase change memory material, according to some embodiments, comprises in atomic percent:
10 to 30 Ge; 15 to 30 As, or a combination of As and Sb, wherein the atomic percent of As is greater than the atomic percent of Sb; and 50 to 60 Te.
[0061] The phase change memory material can further comprise Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof is 20 percent or less, in some embodiments. The atomic percent of the Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof can be 15 percent or less.
[0062] Bulk GeAsTe glasses such as those indicated by the solid circles 10 in FIG. 1 , can be thermally crystallized to yield a highly reflective phase or phase assemblage. In the case of glasses with compositions on the As 2 Te 3 —GeTe join 12 , this phase is one of the homologous series of mixed layer compounds that can be represented by the formula: As 2 Te 3 (GeTe) n , where n is an integer. For example, for the material represented by circle 14 , with a Ge:As ratio of 1:2, this phase is GeAs 2 Te 4 , i.e. n=1. These bulk glasses can be prepared using the chalcogenide glass processing technique of ampoule melting.
[0063] For applications in solid state memory, these materials are used in thin film format. Thin films can be fabricated by a variety of techniques, for example, magnetron sputtering, thermal evaporation and pulsed laser deposition. These thin films can be deposited onto a substrate and can be utilized in phase change memory devices.
[0064] According to one embodiment, the thin films are 2 microns or less in thickness, for example, 1 micron or less, for example, 0.5 microns or less. In some embodiments, the thickness of the thin film ranges from 20 nanometers to 1 micron, for example, 40 nanometers to 1 micron, for example, 50 nanometers to 1 micron. Although specific ranges are indicated, in other embodiments, the thickness may be any numerical value within the ranges including decimals.
EXAMPLES
[0065] Using pulsed laser deposition, thin films of GeAs 2 Te 4 , in this example, Ge 14.3 As 28.6 Te 57.1 were deposited on Eagle XG™ glass substrates with a 248-nm excimer source and high vacuum (10 −6 Torr) deposition chamber. Ablation from the target to prepare substantially continuous thin films was done for 9000 to 36000 pulses. Portions of the thin film articles were subsequently heated at 250° C. in air for times ranging from 10 to 180 mins (the heat treatment temperature was selected so as to coincide with the peak crystallization temperature of the bulk glass as measured by differential scanning calorimetry at a 10° C./min heating rate).
[0066] Visual inspection of the heated articles showed increased reflectivity. This observation was substantiated by quantitative data showing an increase in reflectivity from ˜40 to ˜60% at 500-700 nm as the heating time increased above 10 mins as shown in FIG. 2 . Increased reflectivity was evident from the as deposited articles and those articles heated for 10 mins, shown by line 16 , and line 18 , respectively, to those articles heated for 30 mins, 60 mins, and 180 mins, shown by lines 20 , 24 , and 22 , respectively.
[0067] Grazing angle X-ray diffraction confirmed that the increase in reflectivity of the samples heated for 30 mins or longer was due to crystallization of GeAs 2 Te 4 .
[0068] X-ray diffraction data for conventional phase change memory materials, GeSb 2 Te 4 and GeAsSbTe 4 , is shown in FIG. 4 and FIG. 5 , respectively. The phase in the crystallized version of these films is cubic. This is deduced from the presence of only four peaks at d-spacing values near 3.5, 3.1, 2.1 and 1.7 A; this is a diagnostic of the so-called “rocksalt” or NaCl structure.
[0069] X-ray diffraction data for materials according to the present invention, GeAs 2 Te 4 and GeAs 1.9 Bi 0.1 Te 4 , is shown in FIG. 6 and FIG. 7 , respectively. The increased number of peaks as compared to the cubic materials demonstrates that the materials according to the present invention comprise a hexagonal crystalline phase. X-ray diffraction data of the additional compositions shown in Table 1 were found to have peaks consistent with a hexagonal crystalline phase.
[0070] Additional Ge 14.3 As 28.6 Te 57.1 thin film articles were heated at 350° C. in air for times ranging from 1 to 10 mins. Reflectivity data for these articles is shown in FIG. 3 . Increased reflectivity was evident from the as deposited articles shown by line 26 to those articles heated for 1 min, 5 mins, and 10 mins, shown by lines 28 , 30 , and 32 , respectively.
[0071] This method was repeated for the compositions described in Table 1 and had similar results. Similar results are also expected for other thin films derived from samples with compositions on the As 2 Te 3 —GeTe join, as well as from other GeAsTe glasses within the following approximate compositional ranges in atomic percent: 5-45% Ge, 5-40% As, and 45-65% Te, and for compositions further comprising Al, Si, Ga, Se, In, Sn, Tl, Pb, Bi, P, S, or a combination thereof. These additional modifications should not degrade the phase change characteristics of these materials.
[0072] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Phase change memory materials and more particularly GeAs telluride materials useful for phase change memory applications, for example, optical and electronic data storage are described.
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FIELD OF THE INVENTION
The present invention relates to automatic execution of media placed in removable disc drives. In particular, the present invention relates to an apparatus and method for externally initiating automatic execution of media inserted into basic removable disc drives.
BACKGROUND OF THE INVENTION
Current personal computer systems support a variety of storage device drives. These drives may store information on magnetic discs, a.k.a. floppy discs, or on optical discs, such as CD-ROMs or a re-writable phase change discs (PD). Storage discs may be internal; i.e. permanently incorporated into the drive, or the discs may be removable. The drives themselves may be permanent fixtures of a particular computer system or they may be removable. As used herein, the phrase “removable disc drive” means any drive, internal or removable, that accepts removable discs.
Some CD-ROM disc drives provide an internal mechanism to automatically execute programs residing on a CD-ROM upon insertion of the CD-ROM into the CD-ROM drive. This mechanism searches the root directory of the CD-ROM to locate a file called “autorun.inf”. A typical “autorun.inf” file looks like the following:
[AutoRun]
Load=ProgramName.exe
Icon=ProgramName.ico
In response to an “autorun.inf” file the CD-ROM disc drive causes the computer operating system to display the icon for ProgramName and to automatically execute ProgramName.exe.
In contrast to these CD-ROM disc drives, most removable disc drives lack an internal mechanism to automatically initiate execution of autorun.inf files, forcing computer users to take some positive action to initiate execution of programs residing on discs inserted into a removable disc drive. Hereinafter, removable disc drives lacking an internal mechanism to initiate automatic execution of programs stored on removable discs shall be referred to as basic removable disc drives.
SUMMARY OF THE INVENTION
The computer readable memory of the present invention enables a computer to initiate automatic execution of removable discs placed in basic removable disc drives. The computer readable memory stores a first, second, and third set of instructions. The first set of instructions directs a computer to determine whether a removable disc has been inserted into a basic removable disc drive. The second set of instructions directs the computer to inform the operating system that the removable disc has been inserted into the basic removable disc drive, causing the operating system to automatically execute an autorun.inf file on the removable disk without any user input. The third set of instructions directs the computer to repeat the execution of the first and second set of instructions while the computer does not seek to power down.
Because the AutoRun functionality of the present invention is realized via software, the present invention avoids both hardware changes to basic removable disc drives and changes to existing operating systems. Users of the present invention need not replace any of their existing system hardware or software to obtain the AutoRun functionality of the present invention. Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. In the accompanying drawings similar references indicate similar elements.
FIG. 1 illustrates a computer system according to the present invention.
FIG. 2 illustrates the inter-relationship of the software modules of the present invention.
FIG. 3 illustrates the instructions of the Installer module.
FIG. 4 illustrates instructions for dynamically loading AutoRun software modules.
FIG. 5 illustrates instructions for enabling power efficient operation of the AutoRun code.
FIG. 6 illustrates the instructions for enabling future operation of the Un-Installer module.
FIG. 7 illustrates the instructions of the AutoRun Driver module.
FIG. 8 illustrates the instructions for resolving access conflicts.
FIG. 9 illustrates the instructions of the Drive Detector module.
FIG. 10 illustrates the instruction of the Un-Installer module.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A. Introduction
FIG. 1 illustrates in block diagram form computer 20 constructed in accordance with an embodiment of the invention. As will be described in more detail below, the AutoRun Code 30 of the present invention alters the operation of computer 20 enabling it to automatically execute an autorun.inf file stored on a removable disc in response to the disc's insertion into a basic removable disc drive. Because the present invention implements AutoRun functionality via software, basic removable disc drives; i.e. those lacking an internal AutoRun functionality, may be easily and inexpensively retrofitted without any hardware changes or changes to operating system (OS) 31 .
Prior to a more detailed discussion of AutoRun Code 30 , consider computer 20 . Computer 20 includes a Central Processing Unit (CPU) 22 that communicates with memory 28 over a system bus 26 . CPU 22 determines and takes the appropriate action in response to each user command and internal state by executing instructions stored electronically in memory 28 , including the instructions of operating system (OS) 31 and AutoRun Code 30 . CPU 22 also communicates with a set of input/output (I/O) devices 24 over system bus 26 . (I/O) devices 24 include a keyboard, mouse, video monitor, and printer (not illustrated). (I/O) devices 24 include embedded disc drives and removable disc drives. These drives may read optical or magnetic discs. The interactions between CPU 22 ,(I/O) devices 24 , system bus 26 , and memory 28 are known in the art. The present invention is directed toward the execution of AutoRun Code 30 in connection with these elements.
B. Overview of AutoRun Code
As shown in FIG. 1, AutoRun Code 30 includes four modules: Installer 32 , AutoRun Driver 34 , Drive Detector 36 and Un-Installer 38 . Installer 32 dynamically loads AutoRun Driver 34 , Drive Detector 36 and Un-Installer 38 into memory 28 from their initial memory location 25 outside computer 20 . AutoRun Driver 34 forces OS 31 to process an autorun.inf file residing on a removable disc upon detecting the presence of the removable disc within a basic removable disc drive. AutoRun Driver 34 uses Drive Detector 36 to identify removable disc drives associated with computer 20 . Given this knowledge, AutoRun Driver 34 polls the identified removable disc drives to determine whether a removable disc has recently been inserted into one of them, and if so, initiates automatic processing of an autorun.inf file on the removable disc, if one exists. At the computer user's command, Un-Installer 38 removes the AutoRun functionality from computer 20 by reversing the changes to computer 20 made by Installer 32 .
FIG. 2 illustrates explicitly the relationship between modules 32 , 34 , 36 and 38 discussed above. Implementation of the AutoRun feature begins with installation into memory 28 of AutoRun Code modules 34 , 36 , and 38 by Installer 32 . Installer 32 runs just once on computer 20 and its execution is initiated by the computer user. After installation, automatic execution of AutoRun Driver 34 begins. AutoRun Driver 34 and Drive Detector 36 continue running until the computer user decides to disable the AutoRun feature by launching Un-Installer 38 .
C. The Installer
FIG. 3 illustrates in flow diagram form instructions for Installer 32 . Installer 32 , as well as all other AutoRun Code modules discussed herein, may be realized in any computer language, including C++.
Execution of Installer 32 begins in response to a user's command to install AutoRun Code 30 . The method used to launch Installer 32 varies depending upon the approach used to distribute AutoRun Code 30 . According to one conventional distribution approach, AutoRun Code 30 is placed on a removable disc. To facilitate its easy discovery and execution, Installer 32 is placed in the root directory of the removable disc. Another popular distribution approach is posting AutoRun code 30 on a website. Site visitors interested in acquiring AutoRun capability can launch Installer 32 from the site. Regardless of the distribution approach used, Installer 32 need not copy itself into memory 28 because Installer 32 needs to be run only once on computer 20 to add AutoRun functionality for basic removable disc drives associated with computer 20 .
Briefly described, Installer 32 performs three tasks. First, during step 50 , Installer 32 dynamically loads into memory 28 AutoRun Driver 34 , Drive Detector 36 and Un-Installer 38 . Second, during step 52 Installer 32 enables power efficient operation of AutoRun. Finally, during step 54 Installer 32 enables future operation of Un-Installer 38 .
Given that brief description of Installer 32 , consider now FIG. 4, which illustrates in flow diagram form instructions 50 for dynamically loading AutoRun Driver 34 , Drive Detector 36 and Un-Installer 38 into memory 28 without re-booting computer 20 . Within the Windows™ OS 31 no documented way exists to dynamically load device drivers, such as AutoRun Driver 34 , into the appropriate block device chains without rebooting. However, analysis reveals that the Windows™ OS dynamically loads device drivers when a SCSI controller exists and is refreshed. For this reason, Installer 32 creates a “fake” or temporary SCSI controller during step 60 . Subsequently, during step 62 Installer 32 copies AutoRun Driver 34 , Drive Detector 36 and Un-Installer 38 into the computer's I/O subsystem directory. In the Windows™ OS 31 , Installer 32 places modules 34 , 36 , and 38 into the directory named: windows\system\iosubsys. Preparations complete, Installer 32 accomplishes the dynamic loading of modules 34 , 36 and 38 during step 64 by refreshing the fake SCSI controller created during step 60 .
FIG. 5 illustrates in flow diagram form instructions 52 used by Installer 32 to enable power efficient operation of the AutoRun feature. During step 70 Installer 32 first enables OS 31 to perform AutoRun on removable discs. Without this step, OS 31 cannot process an autorun.inf file on a removable disc. The Windows™ OS does not document any means for enabling AutoRun for removable disc drives; however, research revealed a relevant registry key named: Software\Microsoft\Window\CurrentVersion\Policies\Explorer. For convenience, refer to this registry key as the Explorer key. The Explorer key includes two special keys: NoDriveTypeAutoRun and NoDriveAutoRun. The first key, NoDriveTypeAutoRun, defines what types of drives should process autorun.inf files. During step 70 Installer 32 sets to 0 bit 3 of the NoDriveTypeAutoRun key to enable OS 31 to process autorun.inf files residing on removable discs inserted into removable disc drives.
Enabling the processing of autorun.inf files residing on removable discs can noticeably slow OS operation. This delay arises from repeated pauses by OS 31 to look for an autorun.inf file on a disc in basic removable magnetic disc drive, which is empty typically. To avoid these delays, Installer 32 uses the second Explorer key: NoDriveAutoRun. This second Explorer key uses a bit for each drive to individually enable/disable the AutoRun feature. Thus, during step 72 , for each removable magnetic disc drive, Installer 32 sets the appropriate bit of the NoDriveAutoRun key to disable the AutoRun feature.
Although the AutoRun feature is disabled, as will be discussed shortly, AutoRun Driver 34 assumes the responsibility of detecting removable discs in removable disc drives and does so in a manner that has less impact on OS operation.
FIG. 6 illustrates in flow diagram form instructions 54 , which enable future operation of Un-Installer 38 . Installer 32 performs two tasks to enable operation of Un-Installer 38 . First, during step 80 Installer 32 copies Un-Installer 38 from its initial memory location 25 onto a hard drive of computer 20 . Second, during step 82 Installer 32 adds to OS 31 pertinent information about Un-Installer 38 . For the Windows™ OS this includes adding information to the registry such that Un-Installer 38 exists in the Windows™ Add/Remove Programs facility.
D. The AutoRun Driver
FIG. 7 illustrates in flow diagram form the instructions of AutoRun Driver 34 . AutoRun Driver 34 determines when a removable disc has been inserted into a removable disc drive and in response initiates automatic processing of an autorun.inf file residing on that removable disc.
AutoRun Driver 34 begins by identifying the removable disc drives currently associated with computer 20 during step 36 . How Drive Detector 36 performs this function will be discussed in detail later with respect to FIG. 9 .
Armed with the information from Drive Detector 36 , AutoRun Driver 34 begins the process of polling the identified removable disc drives. During step 90 , AutoRun Driver 34 selects for examination one of the identified removable disc drives. Before attempting to poll the selected removable disc drive, AutoRun Driver 34 first clears any access conflict between itself and OS 31 during step 92 . How AutoRun Driver 34 clears these conflicts will be discussed in detail later with respect to FIG. 8 .
During step 94 AutoRun Driver 34 accesses the selected drive and determines whether a removable disc has recently been inserted into the drive. For the Windows™ OS a number of polling commands are available; however, the polling command chosen should be compatible with the wide range of disc drives that OS 31 can accommodate. Furthermore, preferably, the results of the polling command should be visible to and compatible with the other device drivers associated with computer 20 . Failure to meet this requirement could lead to data loss. While the TEST UNIT READY pass through command may seem to be the logical choice for the polling command during step 94 , this pass-through command is not compatible with certain integrated drive electronics (IDE) disc drives. Analysis revealed that the IOR_MEDIA_CHECK_RESET command met the desired performance criteria for the polling command. Lower level device drivers translate this command into an appropriate lower level command. Thus, for the Windows™ OS, AutoRun Driver 34 uses the IOR_MEDIA_CHECK_RESET command during step 94 to poll the selected removable disc drive.
AutoRun Driver 34 addresses one additional concern during step 94 : making the polling command visible to other drivers, such a disc caches. To ensure that all drivers accessing the selected removable disc drive will have an opportunity to study the results of the polling command, AutoRun Driver 34 sends the polling command through the disc's driver stack using the IOS_SendCommand, rather than communicating directly with the selected disc drive. As a result of these actions during step 94 , AutoRun Driver 34 and all other drivers will be informed of the drive's response to the polling command.
If a removable disc has been inserted recently into the selected removable disc drive, then during step 96 AutoRun Driver 34 forces OS 31 to process an autorun.inf file on the removable disc, if one exists. AutoRun Driver 34 does so for Windows™ OS 31 by issuing the command ISP_DEVICE_ARRIVED.
During step 98 AutoRun Driver 34 turns its attention to power management concerns. Polling of disc drives by AutoRun Driver 34 may lead OS 31 to believe there is on-going system activity and to delay system power down. To prevent this, AutoRun Driver 34 discontinues polling removable disc drives when it determines that OS 31 wishes to power down. Examples of system events that causes AutoRun Driver to cease polling are: system critical shut-down, un-configuration of a device, system shut-down and un-initialization of a device or driver. In response to any of the following messages from Windows™ OS 31 AutoRun Driver ceases polling: AEP_SYSTEM_CRIT_SHUTDOWN, AEP_UNCONFIG_DCB, AEP_SYSTEM_SHUTDOWN and AEP_UNNTIALIZE. Upon detection of any of these events, AutoRun Driver 34 ceases execution until after computer 20 is powered up again. On the other hand, in the absence of any detected desire by OS 31 to power-down, AutoRun Driver 34 branches to step 100 from step 98 .
AutoRun Driver 34 determines during step 100 whether it has polled all removable disc drives it last detected. If not, AutoRun Driver 34 branches back to step 90 and polls a remaining removable disc drive. On the other hand, if all removable disc drives last detected have been polled, then AutoRun Driver 34 advances to step 102 . AutoRun Driver 34 pauses there for a few seconds prior to resume polling of removable disc drives. This pause reduces the impact of AutoRun Driver 34 on system operation. The exact amount of time chosen for this pause is a design choice. In one embodiment, AutoRun Driver 34 pauses 4 seconds before returning to step 36 .
D.1. Clearing Access Conflicts
FIG. 8 illustrates in flow diagram form instructions 92 used by AutoRun Driver 34 to clear disc drive access conflicts. Instructions 92 help insure that the periodic polling of removable disc drives does not degrade their performance. Polling can degrade disc drive performance in two ways. First, increased command traffic can slow disc drive performance and, second, some removable disc drives lose the contents of their internal buffers if polled too quickly after a device change.
Instructions 92 minimize these impacts by determining whether OS 31 is accessing the selected drive or a related drive during step 110 . In the Windows OS 31 , Instructions 92 determine whether a disc drive is being accessed by examining the drive's driver stack. Concerns regarding multiple logical unit drives (hereinafter referred to as multiple LUNs) also cause Instructions 92 to examine the driver stack of related drives during step 92 , when necessary. Multiple LUNs are drives that support multiple types of discs. For example, the phase change drives (PD) accept both standard CD-ROM discs or re-writable optical discs. Multiple LUN drives present themselves to OS 31 as two disc drives. Accessing one of the drives of a multiple LUN drive while the other is being accessed by OS 31 can lead to undesirable race conditions within the multiple LUN. For this reason, if one drive of a multiple LUN is being accessed by OS 31 , Instructions 92 will not access the other related drive.
If it is discovered that the selected drive or a related drive are being accessed by OS 31 , then AutoRun Driver 34 pauses for a few seconds during step 112 . As before, the exact amount of delay is a design choice. After this pause, AutoRun Driver 34 returns to step 110 to determine whether the access conflict has been resolved. AutoRun Driver 34 continues to wait to poll the selected drive until the access conflict resolves itself.
E. The Drive Detector
FIG. 9 illustrates in flow diagram form the instructions of Drive Detector 36 . Drive Detector 36 detects which drives associated with computer 20 accept removable discs and are physical drives and of these which is associated with a multiple LUN. Drive Detector 36 begins in step 120 by broadcasting a configuration check command to IO devices 24 . In the Windows™ OS, Drive Detector 36 uses the message: AEP_CONFIG_DCB. Each IO device 24 responds by identifying its type. During step 122 Drive Detector 31 examines the type of each IO device 24 to identify which devices are physical and accept removable discs. Drive Detector 34 considers physical all direct access drives and optical drives. In the Windows™ OS, these drives are designated by device types: 0x00, 0x07 and 0x84. Devices of type 0x00 may or may not be removable, therefore during step 122 Drive Detector 36 also examines the device flags passed with the AEP_CONFIG_DCB message to determine whether devices of this type are removable and physical.
During step 124 Drive Detector 36 identifies which drives are part of multiple LUNs. For the Windows™ OS, Drive Detector 36 does so by examining the flags associated with the AEP_CONFIG_DCB message for the DCB_scsi_lun. (Note both IDE and SCSI drives may be multiple LUNs.) AutoRun Driver 34 will later use this information to identify possible access conflicts with OS 31 .
F. The Un-Installer
FIG. 10 illustrates in flow diagram form the instructions of Un-Installer 38 . Un-Installer 38 removes AutoRun functionality from computer 20 by reversing the steps taken by Installer 32 . During step 130 Un-Installer 38 eliminates the fake SCSI controller created by Installer 32 . Subsequently, during step 132 , Un-Installer 38 removes the reference to AutoRun Driver 34 in the OS directory. Next, Un-Installer 38 disables the ability of OS 31 to process autorun.inf files by returning the two keys of the Explorer key to their appropriate values during steps 134 and 136 . Finally, during step 138 , Un-Installer 38 removes references to itself in the programs facility. In the Windows™ OS this facility is named Add/Remove Programs.
G. Conclusion
Thus, an apparatus and method for adding AutoRun functionality to a computer including basic removable disc drives that does not require any hardware changes has been described.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
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A computer readable memory to direct a computer to enable AutoRun functionality for basic removable disc drives. The computer readable memory stores a first, second and third set of instructions. The first set of instructions directs the computer to determine whether a removable disc has been inserted into a basic removable disc drive. The second set of instructions directs the computer to inform the operating system that the removable disc has been inserted into the basic removable disc drive, causing the operating system to execute an autorun.inf file on the removable disk without any user input. The third set of instructions directs the computer to repeat the execution of the first and second set of instructions while the computer does not seek to power down.
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FIELD OF THE INVENTION AND RELATED ART
This invention relates to an illumination device and a projection exposure apparatus using the same. More particularly, the invention is concerned with an illumination device usable in a microdevice manufacturing exposure apparatus (called a stepper) for illuminating a pattern formed on a reticle in a manner easily attaining high resolution. In another aspect, the invention is concerned with a projection exposure apparatus using such an illumination device.
Semiconductor device manufacturing technology has recently been advanced significantly and, along with this, the fine processing technique has been improved considerably. Particularly, the optical processing technique has pressed the fine processing into a submicron region, with the manufacture of a device of 1-megabit DRAM. A conventionally adopted method for improving the resolution is mainly to enlarge the numerical aperture (NA) of an optical system while fixing an exposure wavelength. Recently, however, it has been proposed and practiced to use an exposure wavelength of i-line in place of g-line, in an attempt to improve the resolution in accordance with an exposure method using an ultra-high pressure Hg lamp.
Along with the advancement of using g-line or i-line as the exposure wavelength, the resist process itself has been advanced. Such improvements in the optical system and in the process together have accomplished rapid advancement of optical lithography.
Generally it is known that the depth of focus of a stepper is in inverse proportion to the square of the NA. It means that enhancing the resolution into a submicron order necessarily results in a problem of decreased depth of focus.
In consideration of this problem, many proposals have been made to use shorter wavelengths, as represented by an excimer laser, for enhancement of the resolution. It is known that the effect of using a shorter wavelength is in inverse proportion to the wavelength, and the shorter the wavelength is, the deeper the depth of focus is.
On the other hand, independently of using light of shorter wavelength, many proposals have been made to use a phase shift mask (phase shift method), in an attempt to improve the resolution. According to this method, a mask of conventional type is locally provided with a thin film that imparts to light incident on it a phase shift of 180 deg. relative to the light incident on the remaining portion. An example has been proposed by Levenson of the IBM corporation. Here, if the wavelength is denoted by λ, the parameter is denoted by k 1 and the numerical aperture is denoted by NA, then the resolution RP can be give by:
RP=k.sub.1 λ/NA
It is known that the parameter k 1 , whose practical range is usually taken as 0.7-0.8, can be improved to about 0.35 with this phase shift method.
There are many varieties of such a phase shift method, as referred to in a paper by Fukuda et al ("Nikkei Microdevices", July 1990, from page 108).
However, there remains many problems in practically using a phase shift mask of spatial frequency modulation type to improve the resolution. Examples are as follows:
(1) Unestablished technique for forming a phase shift film;
(2) Unestablished CAD technique optimized to a phase shift film;
(3) Existence of a pattern to which no phase shift film can be put;
(4) Necessity of using a negative type resist (in relation to problem (3); and
(5) Unestablished technique for inspection and correction.
Under these circumstances, the phase shift mask method cannot be easily practiced in the semiconductor device manufacturing processes.
An exposure method and apparatus which attains enhanced resolution through an appropriately structured illumination device, has been proposed in Japanese patent application No. 28631/1991, filed in Japan on Feb. 22, 1991, in the name of the assignee of the subject application.
In this exposure method and apparatus, such an oblique projection illumination system is adopted wherein particular attention is paid to a high spatial frequency region around a k 1 factor of 0.5. This illumination system assures a deep depth of focus in the high spatial frequency region.
SUMMARY OF THE INVENTION
Practical semiconductor device manufacturing processes include on one hand a process wherein high resolution of a pattern is required and, on the other hand, a process wherein a not so high resolution of a pattern is required. Thus, what is desired currently is a projection exposure apparatus which can meet the requirement of various resolution performances to be satisfied in various processes.
It is accordingly an object of the present invention to provide a variable or adaptable illumination device or a projection exposure apparatus using the same, by which a suitable illumination method appropriate to the resolution actually required can be selectively assured without decreasing the efficiency of utilization of light.
In accordance with an aspect of the present invention, there is provided an illumination device in which a light emitting portion is disposed in the neighborhood of a first focal point of an elliptical mirror. By using the light from the light emitting portion and through the elliptical mirror, an image of the light emitting portion is formed in the neighborhood of a second focal point of the elliptical mirror. Light from the image of the light emitting portion is projected through an optical integrator having a plurality of small lenses disposed two-dimensionally to illuminate a surface to be illuminated. An optical device is disposed demountably out of the light path, between the elliptical mirror and the integrator, to deflect the light in a predetermined direction, to thereby change the light intensity distribution at the light entrance surface of the integrator.
In accordance with another aspect of the present invention, there is provided an illumination device in which a light emitting portion is disposed in the neighborhood of a first focal point of an elliptical mirror. By using the light from the light emitting portion and through the elliptical mirror, an image of the light emitting portion is formed in the neighborhood of a second focal point of the elliptical mirror. This image is imaged again by an imaging system on the light entrance surface of an optical integrator having a plurality of small lenses disposed two-dimensionally, and a surface to be illuminated is illuminated with the light from the exit surface of the integrator. An optical device is disposed demountably out of the light path, adjacent to the pupil plane of the imaging system, to deflect the light in a predetermined direction, to thereby change the light intensity distribution at the light entrance surface of the integrator.
In accordance with a further aspect of the present invention, there is provided an illumination device in which light from a light source is projected through an optical integrator having small lenses disposed two-dimensionally to illuminate the surface to be illuminated. Between the light source and the integrator, an optical device for deflecting light in a predetermined direction is demountably inserted to the light path, to thereby change the light intensity distribution at the entrance surface of the integrator.
In accordance with a further aspect of the invention, there is provided an illumination device in which a light emitting portion is disposed in the neighborhood of a first focal point of an elliptical mirror. By using the light from the light emitting portion and through the elliptical mirror, an image of the light emitting portion is formed in the neighborhood of a second focal point of the elliptical mirror. Light from the image of the light emitting portion is projected through an optical integrator having a plurality of small lenses disposed two-dimensionally to illuminate a surface to be illuminated. An optical device including at least two prism members is disposed demountably out of the light path, between the elliptical mirror and the integrator, to deflect the light in a predetermined direction, so as to allow selection of a first state in which a light intensity distribution, of rotationally symmetric, having a higher intensity at its central portion than at the peripheral portion is defined at the entrance surface of the integrator and a second state in which the light intensity distribution having a higher intensity at the peripheral portion than at the central portion is defined at the entrance surface of the integrator.
In another aspect, the invention provides a method of manufacturing microdevices such as semiconductor memories, liquid crystal panels, magnetic heads or CCDs, for example, using an illumination device such as above.
In a further aspect, the invention provides an exposure apparatus for manufacture of microdevices that uses an illumination device such as above.
The deflecting member usable in the present invention may be of the type that it refracts light at its light deflecting surface to shape or divide the light, or that it reflects the light at its deflecting surface to shape or divide the light.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a main portion of a first embodiment of the present invention.
FIGS. 2A, 2B and 2C are schematic views, respectively, for explaining a portion of FIG. 1.
FIGS. 3A, 3B and 3C are schematic views, respectively, for explaining a portion of FIG. 1.
FIG. 4 is a schematic view for explaining the optical function of a lens system 9 of FIG. 1.
FIG. 5 is a schematic view for further explaining the optical function of the lens system 9 of FIG. 1.
FIG. 6 is a schematic view for further explaining the optical function of the lens system 9 of FIG. 1.
FIGS. 7A and 7B are schematic views, respectively, of a modified form of prism member usable in the present invention.
FIGS. 8A and 8B are schematic views, respectively, of a further modified form of a prism member usable in the present invention.
FIG. 9 is a schematic view of a portion of a second embodiment of the present invention.
FIGS. 10A-10C are schematic views, respectively, each for explaining a portion of a third embodiment of the present invention.
FIGS. 11A and 11B are schematic views, respectively, each for explaining the optical function of the third embodiment.
FIGS. 12A and 12B are schematic views, respectively, each for further explaining the optical function of the third embodiment.
FIGS. 13A and 13B are graphs, respectively, each showing an example of a light intensity distribution in the third embodiment of the present invention.
FIGS. 14A and 14B are graphs, respectively, each showing a further example of a light intensity distribution in the third embodiment of the present invention.
FIGS. 15A-15C are schematic views, respectively, each showing a main portion of a fourth embodiment of the present invention.
FIG. 16 is a schematic view of a main portion of a fifth embodiment of the present invention.
FIG. 17 is a schematic view of a main portion of a sixth embodiment of the present invention.
FIGS. 18A and 18B are schematic views for explaining a portion of FIG. 17.
FIGS. 19A and 19B are schematic views for further explaining a portion of FIG. 17.
FIGS. 20A-20C are schematic views, respectively, each for explaining the state of incidence of light upon a light entrance plane 10a of an optical integrator 10 of FIG. 17.
FIG. 21 is a schematic view of an apertured stop.
FIG. 22 is a schematic view of a main portion of a seventh embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic view of an illumination device and a projection exposure apparatus using the same, according to an embodiment of the present invention. In this embodiment, the invention is applied to a reduction projection type exposure apparatus, called a stepper. This exposure apparatus can be used for manufacture of microdevices such as semiconductor memories, CCDs, liquid crystal panels or a magnetic head, for example.
Denoted in the drawing at 1 is a light source such as a high luminance ultra high pressure Hg lamp, for example, for emitting ultraviolet light or deep UV light. The light source 1 has its light emitting portion 1a disposed adjacent to the first focal point of an elliptical mirror 2.
The light emanating from the light source 1 is reflected and collected by the elliptical mirror 2, and then it is reflected by a cold mirror 3 by which an image 1b of the light emitting portion 1a (an image of the light source) is formed in the neighborhood of the second focal point 4 of the elliptical mirror 2. The cold mirror 3 has a multilayered film and it mainly serves to transmit infrared light but to reflect ultraviolet light.
Denoted at 101 is an imaging system having two lens systems 5 and 9. It serves to image the light source image 1b, formed in the neighborhood of the second focal point 4, upon an entrance plane 10a of an optical integrator 10 through the cooperation of an optical device 8. The optical device 8 comprises a prism member 6 having a conical prism, for deflecting received light to a predetermined direction, and a parallel flat plate 7 for projecting received light directly.
Denoted at 8a is a holding member by which the prism member 6 and the parallel plate 7 of the optical device 8 can be alternately and selectively placed on the light path. When the parallel plate 7 is on the path, the imaging system 101 is defined as a telecentric system on the exit side. The optical device 8 is disposed in the neighborhood of the pupil plane of the imaging system, where the opening of the elliptical mirror is imaged.
The optical integrator 10 comprises a plurality of small lenses which are arrayed two-dimensionally, and it serves to define a secondary light source 10c in the neighborhood of the exit surface 10b thereof. Denoted at 11 is a stop member having a plurality of apertures. The stop member is provided with a mechanism by which the shape of an aperture on the light path can be changed. To the secondary light source 10c, the stop member 11 is disposed in such a region in which discrete secondary light source elements do not overlap.
Denoted at 14a is a lens system for collecting the light from the exit surface 10b of the optical integrator 10 and for illuminating, through the stop member 11 and a mirror 13 as well as a collimator lens 14b, a reticle (surface to be illuminated) 15 placed on a reticle (surface to be illuminated) 15 placed on a reticle stage 16. The lens system 14a and the collimator lens 14b constitute a condensing lens system 14.
Denoted at 17 is a projection optical system for projecting, in a reduced scale, a pattern formed on the reticle 15 upon the surface of a wafer 18 which is placed on a wafer chunk 19. Denoted at 20 is a wafer stage on which the wafer chuck 19 is mounted. In this embodiment, with the condensing lens system 14, an image of the secondary light source 10c formed in the neighborhood of the exit surface 10b of the optical integrator 10, is formed in the neighborhood of a pupil 17a of the projection optical system 17.
Next, description will be made of the manner of changing the light intensity distribution of the image of the secondary light source, which image is formed at the pupil plane 17a of the projection optical system 17, in accordance with the present embodiment by changing the light intensity distribution at the light entrance surface 10a of the optical integrator 10 through the optical device 8.
FIGS. 2A and 3A each illustrate the light path from the elliptical mirror 2 (FIG. 1) to the optical integrator 10, the path being extended. The mirror 3 is not shown in FIG. 2A or 3A. The illustrations of FIGS. 2A-2C and 3A-3C explain that the light intensity distribution upon the entrance surface 10a of the optical integrator 10 is changed by alternately selecting the elements 6 and 7 of the optical device 8.
FIGS. 2A-2C correspond to a case where the parallel plate 7 of the optical device 8 is disposed on the light path, whereas FIGS. 3A-3C correspond to a case where the prism member 6 of the optical device 8 is disposed on the light path.
The illumination system of FIG. 2A is adapted for a first state of projection in which a very high resolution is not required but in which a larger depth of focus is assured. The illumination system of FIG. 3A is adapted for a second state of projection in which a high resolution is required mainly.
FIGS. 2C and 3C each is a schematic representation of a light intensity distribution upon the light entrance surface 10a of the optical integrator 10. The zone depicted by hatching in the drawings denotes the region of higher light intensity, as compared with the remaining region. FIGS. 2B and 3B illustrate a distribution of light intensity I along the X-axis direction (FIG. 2C or 3C).
In FIG. 2A, the parallel plate 7 of the optical device 8 is disposed on the light path, and the light source image 1b as formed at the second focal point 4 of the elliptical mirror 2 is imaged by the imaging system 101 upon the light entrance surface 10a of the optical integrator 10. Here, as seen in FIG. 2B, the light intensity distribution in section upon the light entrance surface 10a of the optical integrator 10 has an approximately Gaussian shape which is rotationally symmetric.
In FIG. 3A, the prism member 6 of the optical device 8 is placed on the light path, and the light source image (point image) 1b formed at the second focal point 4 of the elliptical mirror 2 is imaged, into a ring-like shape, on the light entrance surface 10a of the optical integrator 10 by the imaging system 101. The light intensity distribution on the light entrance surface 10a of the integrator 10 has a ring-like shape such as shown in FIGS. 3B or 3C wherein the light intensity is lower at the optical axis portion but is higher at the peripheral portion. Why this is so will now be explained below.
FIG. 4 schematically illustrates the disposition of the parallel flat plate 7, the lens system 9 and the light entrance surface 10a of the optical integrator 10 of FIG. 2A. In this embodiment, these elements are so disposed that the optical distance between the parallel plate 7 and the forward principal point of the lens system 9 as well as the optical distance between the backward principal point of the lens system 9 and the light entrance surface 10a of the integrator 10 are, if the focal length of the lens system 9 is denoted by f 0 , both equal to a distance f 0 .
Here, the incidence height t 1 , from the optical axis, of the light emanating from the parallel plate 7 with an angle α 0 and impinging on the light entrance surface 10a is expressed as follows:
t.sub.1 =f.sub.0 ·tan α.sub.0
If the height, from the optical axis, of the outermost light passing through the parallel plate 7 is denoted by S 0 , then the angle β of incidence upon the light entrance surface 10a of the integrator is given by:
β=tan.sup.-1 (S.sub.0 /f.sub.0)
It is seen therefrom that, by deflecting the angle of light at the position of the parallel plate 7 (i.e., the forward focal plane of the lens system 9), it is possible to change only the position of incidence of light upon the entrance surface 10a of the optical integrator without changing the angle of incidence.
Based on the optical principle described, in the present embodiment, by interchanging the parallel plate 7 by the prism member 6 comprising a conical prism, the light intensity distribution on the entrance surface 10a of the integrator 10 is changed into a ring-like intensity distribution having a lower intensity at the optical axis portion and a higher intensity at the peripheral portion.
Since the light intensity distribution on the entrance surface 10a of the integrator 10 corresponds to the light intensity distribution of an effective light source which is defined at the pupil plane 17a of the projection optical system 17, by using the prism member 6 in place of the parallel plate 7 such an effective light source having a light intensity distribution having a lower intensity at a central portion (optical axis portion) and a higher intensity at a peripheral portion is defined on the pupil plane of the projection optical system.
In this embodiment, the stop member 11 is provided in the neighborhood of the exit surface 10b of the optical integrator 10. This stop member has a plurality of apertures and is provided with a mechanism for changing, as desired, the aperture shape thereof. The aperture shape which is variable is predetermined and it corresponds to the shape of the secondary light source to be formed at the pupil plane 17a of the projection optical system 17. For example, the stop member may have a ring-like aperture of a property for passing a larger quantity of light at its peripheral portion than at its central portion.
In this embodiment, the selection of the prism member 6 of the optical device 8 singley or the selection of the prism member 6 together with the changing of the aperture shape of the stop member 11 in combination, assures a desired shape of effective light source while attaining a high efficiency of light utilization.
It is to be noted that the provision of the stop member 11 is not a requisition in this embodiment.
With the arrangement of this embodiment as described above, for a reticle 15 pattern having a relatively large minimum linewidth, the structure shown in FIG. 2A is selected (like an illumination system of conventional type), whereby a Gaussian shaped light intensity distribution is provided at the entrance surface 10a of the optical integrator 10 (first state).
On the other hand, for a pattern having a relatively small minimum linewidth, the structure shown in FIG. 3A is selected to provide a ring-like light intensity distribution at the entrance surface 10a of the integrator 10. Also, the aperture shape of the stop member 11 is changed. By this, an illumination device for high resolution projection is assured (second state).
The insertion of the parallel plate 7 in the first state of FIG. 2A is to minimize the difference in optical path length between the lens systems 5 and 9, as compared with that in the case where the prism member 6 is inserted in the second state. If the prism member 6 has a small thickness or if a slight change in optical path length between the lens systems 5 and 9 does not influence the optical performance of the optical integrator 10 or of any other optical elements following it, the parallel plate 7 may be omitted.
FIGS. 5 and 6 are schematic representations for explaining the relationship of the incidence height (heights t 1 and t 2 from the optical axis) at the entrance surface 10a of the optical integrator 10, relative to the position (exit heights S 1 and S 2 ) and deflection angle (α 1 and α 2 ) of light passing through the parallel plate 7, where in the present embodiment the focal length f of the lens system 9 constituting the imaging system 101 is changed.
If in FIG. 5 the focal length of the lens system 9 is f 1 , then t 1 =f 1 tanα 2 applies. Also, in FIG. 6, if the focal length of the lens system 9 is f 2 , then t 2 =f 2 tanα 2 applies.
It is seen from these equations that if the focal length of the lens system 9 is made large then it is possible to obtain, at the entrance surface 10a of the optical integrator 10, an incidence position t 1 of desired height with a small deflection angle α at the position of the parallel plate 7. This means that if the focal length f of the lens system 9 is made large then it is possible to make small the angle of the prism member 6 (prism angle) in the second state. This assures an imaging system 101 of smaller aberration. Practically, in consideration of the size of the prism member 6, the focal length of the lens system 9 may be so set to define a prism angle of 5-20 deg.
The prism member 6 of the optical device of the present invention is not limited to a conical prism. It may have any shape provided that it has a function for deflecting received light in a predetermined direction. For example, pyramidal prisms such as shown in FIGS. 8A and 8B may be used.
FIGS. 7B and 8B schematically illustrate a light intensity distribution on the entrance surface 10a of the integrator 10 when the prism member such as shown in FIG. 7A or 8A is used. The zones depicted by hatching denote regions of higher intensity as compared with the remaining region.
It is possible in the present invention to use three or more types of interchangeable optical members such as prisms and a parallel plate, rather than only two optical members of the prism 6 and the parallel plate 7 are interchanged as in the present embodiment.
Further, the pyramidal prism such as shown in FIG. 7A may be rotated about the optical axis, for smoothing with respect to time, to provide a ring-like light intensity distribution such as shown in FIG. 3C.
Still further, the light source 1 may be displaced along the optical axis concurrently with the interchange of the prism member, to change the size of the higher light intensity region.
FIG. 9 is a schematic view of a main portion of a second embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, a half mirror 30 is disposed on the light path at the position before (light source 1 side of) the optical integrator 10, so that a portion of the light from the imaging system 101 is directed to a photodetector 31 which may comprise a CCD or a quadrant sensor. The remaining portion is of the same structure as that of the first embodiment.
In this embodiment, the light intensity distribution at the light entrance surface 10a of the optical integrator 10 is measured indirectly to monitor the same. This allows adjustment of the imaging system 101 while monitoring changes in light intensity and/or light intensity distribution at the entrance surface 10a.
In this embodiment, a mechanism 60 for rotating the optical member 6 about the optical axis or for shifting the same with respect to the optical axis, may be used. This provides the ability to change the light intensity distribution at the entrance surface 10a of the integrator 10 into a desired shape easily.
FIGS. 10A is a schematic view of a main portion of a third embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, in addition to the insertion of the prism member 6 into the light path, the lens system 9 is replaced by a lens system 33 of a different focal length which is disposed at the entrance face 10a side of the optical integrator 10. The remaining portion is of the same structure as that of the first embodiment.
In this embodiment, light is collected to a region narrower than the entrance surface 10a of the integrator 10, and light intensity distribution of a desired shape is obtained.
Referring now to FIGS. 11A, 11B, 12A and 12B, the optical function of this embodiment will be explained.
FIGS. 11A-12B schematically illustrate the light path from the optical device 8 (prism 6 and parallel plate 7) to the integrator 10. FIGS. 13A, 13B, 14A and 14B show a light intensity distribution at the entrance surface 10a of the integrator 10, defined by using the prism member 6 or the parallel plate 7.
FIG. 11A shows the arrangement where, in the first embodiment, a conventional type illumination is to be done. Generally, the angle of light rays that can enter the optical integrator is determined and, in the example of FIG. 11A, the angle is θ 1 . Thus, the optical system before the integrator 10 is designed so that the angle of incidence upon the integrator 10 becomes not greater than the angle θ. Here, in the light intensity distribution at the entrance surface 10a of the integrator 10, the degree of convergence is limited due to Lagrange's invariant. For example, it is not possible to improve the degree of convergence beyond that of FIG. 13A. An attempt to obtain a higher degree of convergence simply ends in that the angle of incidence upon the integrator 10 goes beyond the angle θ.
FIG. 11B shows the state where, in the first embodiment, the prism member 6 is inserted into the light path. FIG. 13B shows a corresponding light intensity distribution at the entrance surface 10a. Here, the maximum incidence angle of the light upon the entrance surface 10a, at the point S 1 , is θ 1 the same as in the FIG. 11A example. However, the effective light angle of the light that actually enters is θ 2 .
As seen from FIG. 12A, with the provision of an optical device 32 (which may comprise a prism or a field lens) in front of the entrance surface 10a, it is possible to reduce the maximum incidence angle. FIG. 14A shows a corresponding light intensity distribution at the entrance surface 10a.
Here, since the maximum incidence angle is loosened, by shortening the focal length of the optical system from the prism 6 to the optical integrator it is possible to obtain a higher degree of convergence. FIG. 12B shows an example wherein the degree of convergence. FIG. 12B shows an example wherein the degree of convergence is improved on the basis of such an optical principle just described. A corresponding light intensity distribution is shown in FIG. 13B. In the example of FIG. 12B, the prism member 6 has an enlarged prism angle so as to obtain a light intensity distribution of a ring-like shape.
In this embodiment, the insertion of the prism member 6 as described causes shift of the angle of incidence at the entrance surface 10a of the integrator 10 with the maximum incidence angle being unchanged. By correcting such shift and optimizing the incidence angle, the incidence angle is loosened. Thus, it becomes possible to increase the degree of convergence to the limit where the incidence angle becomes equal to the critical incidence angle.
Practical means for this end may be using a zoom system for the optical system from the prism member 6 to the integrator 10; using interchangeable optical systems; provision of a prism (conical prism where the prism member 6 comprises a conical prism; a pyramidal prism where the prism member 6 comprises a pyramidal prism) in front of the integrator 10; insertion of an aspherical lens; or an appropriate combination of them.
FIGS. 15A-15C are schematic views of a portion of a fourth embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, the position of the optical device 8 (the position of prism member 6 and/or parallel plate 7) is shifted from the pupil of the imaging system 101 and the focal length of the optical system 9 is changed, to thereby converge the light intensity distribution at the entrance surface 10a of the optical integrator 10. The remaining portion is of the same structure as that of the first embodiment.
In FIGS. 15A-15C, reference character P denotes the pupil plane of the lens system 9. FIG. 15A shows the first state of illumination in the first embodiment. The angle of incidence upon the integrator 10 is θ. FIG. 15B shows the second state of illumination in the first embodiment, and the incidence angle is θ the same as in the FIG. 11A example. Here, if the prism member 6 is shifted from the pupil plane P and the beam diameter on the plane P is reduced such as shown in FIG. 15C, then it is possible to make the incidence angle θ' smaller than the angle θ 2 of the FIGS. 11A and 11B examples. In the present embodiment, on this occasion, the focal length of the lens system 9 is changed so as to assure that the light intensity distribution at the entrance surface 10a of the integrator 10 is collected and converged locally.
FIG. 16 is a schematic view of a main portion of a fifth embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, the lens system 5 constituting the imaging system 101 is omitted and the opening 2a of the elliptical mirror 2 is imaged by the lens system 9 upon the entrance surface 10a of the optical integrator 10. Also, the optical device 8 is disposed in the neighborhood of the second focal point of the elliptical mirror 2. The remaining portion is of the same structure as that of the first embodiment.
More specifically, in the embodiment of FIG. 1, an image of the light emitting portion 1a of the light source 1 is formed on the entrance surface 10a of the integrator 10, and the optical device 8 is disposed in the neighborhood of the imaging position of the opening 2a of the elliptical mirror 2 (the position of the image of the opening 2a) which is between the light source 1 and the integrator 10.
In the present embodiment, as compared, the image of the opening 2a of the elliptical mirror 2 is formed on the entrance surface 10a of the integrator 10, and the optical device 8 is disposed at the imaging position of the light emitting portion 1a (the second focal point position of the elliptical mirror 2) which is between the light source 1 and the optical integrator 10.
Thus, in this embodiment, the forward focal point position of the lens system 9 is placed substantially at the second focal point position of the elliptical mirror 2, and by the lens system 9, the light from the light source image 1b at the second focal point is transformed into substantially parallel light which is then directed to the entrance surface 10a of the integrator 10. When the prism member 6 is being inserted and if it is of the type such as shown in FIG. 7A, four parallel lights from the lens system 9 are projected on the entrance surface 10a of the integrator 10.
FIG. 17 is a schematic view of a main portion of a sixth embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, the optical device 8 comprises at least two prism members 6a and 6b disposed along the optical axis and, for changing the light intensity distribution at the entrance surface 10a of the integrator 10, namely, for rendering the illumination system into the second state, the optical device 8 (prism members 6a and 6b) is mounted on the optical axis and, additionally, a portion of the lens system 9a constituting the imaging system 101 is replaced by another lens system 9b so as to reduce the incidence angle of an off-axis principal ray to the entrance surface 10a. This is done for efficient utilization of light.
In the illumination method of this embodiment, in the first state the lens system 9a is placed on the light path (the optical device 8 is not used), so at to provide a light intensity distribution at the entrance surface 10a of the integrator 10, that is, a light intensity distribution at the pupil plane 17a of the projection optical system 17, which distribution is of a rotationally symmetric shape wherein the intensity is higher at the central portion than at the peripheral portion.
The second state is defined by placing the optical device 8 (prism members 6a and 6b) on the light path and by replacing the lens system 9a by the lens system 9b having a different focal length. This makes smaller the angle of incidence of the principal ray upon the entrance surface 10a of the integrator 10, whereby at this entrance surface 10a, namely, at the pupil plane 17a of the projection optical system 17, such a light intensity distribution in which the intensity is higher in the peripheral portion than in the central portion is provided.
Structural features of this embodiment over the first embodiment will be explained in more detail.
In FIG. 17, lens system 5 collects the light from the light source image 1b formed in the neighborhood of the second focal point 4, and it emits parallel light. The imaging system 101 (lens systems 5 and 9a) is telecentric on the exit side. At least a portion of the collecting lens 14 is made movable along the optical axis, to adjust the light intensity distribution on the reticle 15.
In this embodiment, in accordance with the orientation and/or the linewidth to be resolved of the pattern of the reticle 15, for example, the lens system 9a which is a constituent element of the imaging system 101 is replaced by the optical device 8 (including two prisms 6a and 6b) and the lens system 9b, to change the light intensity distribution at the entrance surface 10a of the integrator 10. Additionally, if necessary, the aperture shape of the stop member 11 is changed to change the light intensity distribution of the image of the secondary light source which image is formed at the pupil plane 17a of the projection optical system 17.
Next, the manner of changing in this embodiment the light intensity distribution on the entrance surface 10a of the integrator 10 as well as the light intensity distribution of the image of the secondary light source to be formed on the pupil plane 17a of the projection optical system 17, on the basis of the optical device 8, will be explained.
FIGS. 18A through 19B each schematically illustrate the light path from the elliptical mirror 2 to the optical integrator 10 of FIG. 17, the path being extended. The mirror 3 is not shown in Figure these figures. The illustrations of Figures these figures explain that the components of the optical device 8 are interchanged to change the light intensity distribution on the entrance surface 10a of the integrator 10.
FIG. 18A shows the state in which the lens system 9a is placed on the light path. FIG. 19A shows the state in which the lens system 9a is removed and, in place thereof, the prism members 6a and 6b of the optical device 8 and the lens system 9b are placed on the light path.
The illumination system of FIG. 18A is in the first state of projection in which a very high resolution is not required but a large depth of focus is assured, as in the illumination method of a conventional type. The illumination system of FIG. 19A is in the second state of projection, according to the present invention, mainly for attaining high resolution.
FIG. 18B and FIG. 19B each schematically shows a corresponding light intensity distribution on the entrance surface 10a of the integrator 10. The zone depicted by hatching denotes the region of higher intensity as compared with the remaining region. In these illustrations, the distribution of light intensity I along the X-axis direction are depicted.
FIGS. 20A, 20B and 20C are schematic representations, for explaining the light rays impinging on the optical integrator 10, in the systems of FIGS. 18A and 19A. Reference characters +θ and -θ each denotes the range (angle) of light rays that can enter the optical integrator 10 (that can emerge from the integrator without being eclipsed). A grid portion in each illustration depicts the zone in which the light intensity is higher than that of the light entering the integrator 10.
FIG. 18A shows the optical arrangement in ordinary illumination. Here, the light intensity distribution at the entrance face 10a of the integrator 10 is like a Gaussian distribution such as shown in FIG. 18B. The incidence angle thereof is such as shown in FIG. 20A. When in this state the illumination for high resolution is to be done, there may be a method in which a stop 121 having an aperture 121a such as shown in FIG. 21 is inserted at the back of or in front of the integrator 10. However, with this method, only the light in the hatched zone of the light intensity distribution of FIG. 18A, can be used and, therefore, the illuminance decreases considerably.
In this embodiment, in consideration thereof, as shown in FIG. 19A the lens system 9a is replaced by the lens system 9b of smaller focal length (the optical components are disposed so that, if the focal length of the lens system 9b is f 9b , the optical distance between the prism 6a and the lens system 9b and the optical distance between the lens system 9b and the entrance surface 10a of the integrator 10 are both equal to f 9b ), such that the light intensity distribution as shown in FIG. 19B, is provided at the entrance surface 10a of the integrator 10.
Additionally, the prism member 6b having an appropriate prism angle is inserted in front of the integrator 10, by which the incidence angle of light rays (incidence angle of off-axis light) is made smaller such as shown in FIG. 20C. This assures efficient impingement or entrance of light into the integrator 10. Thus, almost all the input light can be used for the illumination.
On the basis of the optical principle described above, the present embodiment uses the optical arrangement such as shown in FIG. 19A, by which illumination for high resolution is assured without a substantial loss of illuminance at the surface to be illuminated.
The prism member 6a or 6b of pyramidal shape provided within the imaging system 101 may have a shape such as shown in FIG. 8, for example. Of course, it may be a conical prism.
While the embodiment has been explained with reference to an example wherein the lens system 9a of FIG. 18A for ordinary illumination is replaced by the lens system 9b of FIG. 19A for high resolution illumination, the lens elements of the lens system 9a may be displaced (like a zoom lens system) to define the same condition as by the lens system 9b. Only some of the lens elements may be moved like a zoom lens system or, alternatively, some lens elements may be replaced by different lens elements.
The stop member 121 for high resolution such as shown in FIG. 21 may be used as desired, or it may be omitted. Further, while in this embodiment the focal length of the lens system 9a is changed to change the magnification of the imaging system 101, the focal length of the lens system 5 may be changed. Alternatively, both of the focal lengths of the lens systems 5 and 9 may be changed.
In this embodiment, there are cases wherein, in response to the interchange of the ordinary illumination (first state) and the illumination for high resolution (second state), uniformness in illuminance (non-uniformness of illuminance) upon the surface being illuminated changes into axial symmetry. On that occasion, a portion of the optical system 14 may be displaced along the optical axis to change aberration such as distortion to thereby correct for the axially symmetric non-uniformness of illuminance upon the surface (reticle 15 surface) to be illuminated.
While in the preceding embodiment the reticle 15 (surface to be illuminated) is disposed just after the optical system 14, an additional imaging system may be disposed between the optical system 14 and the reticle such that a plane which is optically conjugate with the reticle 15 surface with respect to the additional imaging system may be illuminated.
FIG. 22 is a schematic view of a main portion of a seventh embodiment of the present invention.
In this embodiment, as compared with the first embodiment of FIG. 1, a half mirror 43 is disposed between the integrator 10 and the surface 15 to be illuminated, so as to allow detection of the amount of exposure of the surface being illuminated. The remaining portion is of substantially the same structure as that of the first embodiment.
In FIG. 22, denoted at 44 is the reticle pattern surface or a plane which is optically conjugate with the reticle pattern surface. Denoted at 45 is a pinhole member which is disposed at a position optically conjugate with the plane 44. Denoted at 33 is a photosensor (e.g., a CCD or quadrant sensor).
With this arrangement of the present embodiment, it is possible to monitor the effective light source distribution at the center of the surface being illuminated. Also, in this embodiment it is possible to concurrently monitor, with the photodetector 31, the amount of exposure of the surface being illuminated.
While in this embodiment the half mirror 43 is placed between the lens system 13a and the collimator lens 14b, it may be disposed at any position between the integrator 10 and the surface 15.
In accordance with the present invention, in consideration of fineness and/or orientation of a pattern of a reticle to be projected and transferred, an illumination system suited to such pattern can be selected.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
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An illumination device, includes a secondary light source forming system having a deflecting member with a conical light deflecting surface for transforming received light into substantially ring-like light, the secondary light source forming system forming a ring-like secondary light source by using the ring-like light; and an optical system for projecting divergent lights from portions of the secondary light source obliquely onto a surface to be illuminated so that the projected lights are superposed one upon another on the surface.
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RELATED U.S. APPLICATION DATA
[0001] Provisional Application No. 61/130,699, filed Jun. 2, 2008.
FEDERALLY SPONSORED RESEARCH
[0002] The invention that is the subject of this application was developed with federal funding through to the Small Business Innovation Research (SBIR) program. Accordingly, the applicant retains its rights to the intellectual property created, subject to the standard patent rights clause as set forth in the Code of Federal Regulations at 37 CFR 401.14. Under this clause the U.S. Government has a nonexclusive, nontransferable, irrevocable, royalty-free license to practice the invention for U.S. Government purposes only.
FIELD OF THE INVENTION
[0003] The present invention relates to systems for recovering unmanned aerial vehicles (UAVs).
BACKGROUND OF THE INVENTION
[0004] UAVs are widely used for military and non-military uses. Roles for UAVs include reconnaissance and offensive strike missions. Adoption of UAVs for use aboard ships, however, is limited largely because of the challenges of recovery at sea. The challenges include small flight decks and wave-induced ship motion.
[0005] Methods of recovery that have been employed at sea include deck-mounted nets and water landings. Drawbacks to net-based capture include the risk of damage to the UAV and the potential for the UAV to be ensnared in the net. Drawbacks to water landing include the necessity to modify the UAV heavily for water landings and the need to recover the UAV from the water after landing.
[0006] Other systems for shipboard UAV recovery, based instead on arresting lines, are disclosed in U.S. Pat. Nos. 7,059,564 and 7,219,856. The disclosed system in U.S. Pat. No. 7,059,564 includes a cable hanging vertically from a boom extending out over the side of the ship. The UAV with special fastener devices at the wing tips is flown into the hanging cable and then captured when the cable slides into one of such devices and becomes attached to the cable. The disclosed system in U.S. Pat. No. 7,219,856 includes a boom that holds a line over the side and parallel to the deck of the ship. The UAV with an attached hook that is disclosed in U.S. Pat. No. 7,143,976 is flown above the line and then captured when the hook snags the line. These recovery systems offer distinct advantages over net-based and water landing methods. An important advantage over the net-based method offered by both of these systems is that recovery occurs over the side of the ship, which reduces the risk of collision with the ship and allows recovery to occur outside the area of most intense turbulence caused by the air wake of the ship superstructure. A drawback of the system disclosed in U.S. Pat. No. 7,059,564 is that the UAV must be designed to accommodate a severe turning moment caused by the arresting line force exerted on a wing tip. In addition, the airframe of the UAV must be heavily modified so that the leading edges of the airframe and wings can withstand impact with the hanging cable and that the cable can slide reliably to a wing-tip fastener. This system has been successfully operated using small UAVs (i.e., under 50 lbs. weight), but is unlikely to be scalable to UAVs of middle or large size (e.g. 200-1000 pounds), due to the higher energies involved in turning moments and cable impacts when masses are greater, yet fixed materials strength. A drawback of the system disclosed in U.S. Pat. No. 7,219,856 is that it cannot accommodate significant vertical flight path errors that are caused by wind buffeting or guidance errors. In addition, the boom will rotate upwards and downwards as the ship rolls and heaves, seriously complicating the hook capture task. A further drawback of both of these recovery systems is that, after arrest, the UAV is left dangling in a near-vertical orientation, thus complicating handling and placement on deck.
[0007] As a consequence, there is a need for a UAV recovery system that, in addition to the capability of capturing a UAV over the side of a ship, can accommodate a wide range of UAV sizes, large, wave-induced ship motions, and substantial vertical flight path errors of the incoming UAV, and can easily handle the UAV after capture.
SUMMARY OF THE INVENTION
[0008] The illustrative embodiment of the invention is a system for recovering an airborne UAV that avoids many of the drawbacks of prior art systems.
[0009] In the illustrative embodiment, the UAV recovery system is configured for use on a ship. In that configuration, the recovery system includes the following: a computer-controlled robot arm that is mounted or temporarily secured to the deck and that has a kinematic arrangement of links and joints that is similar to that of a backhoe; a capture mechanism that is mounted on the free end of the robot arm and that includes an arresting line and a winch that pays out and rewinds the arresting line in a controlled fashion during the UAV recovery process; a ship motion sensor such as an inertial measurement unit (IMU) that enables the robot arm to compensate for ship motion prior to capture; a UAV position sensing system that provides real-time estimates of the position of the UAV relative to the capture mechanism, the estimates of which are used for both UAV control and capture mechanism control; a transceiver that sends commands to the UAV guiding it towards the capture mechanism; and an arresting hook that is mounted to the top of the UAV fuselage. The capture mechanism also includes an actuated revolute joint that allows the capture mechanism to be commanded to rotate such that the height of the arresting line segment that is to be snagged by the hook can be varied rapidly. Horizontal positioning errors are accommodated in the same manner as used for over 80 years in tailhook landing systems: by presenting a sufficient length of horizontal cable to the UAV hook. The UAV position sensing system is used in the control of both the UAV and the capture mechanism prior to capture. Arrest is initiated when the UAV snags the arresting line with its top hook.
[0010] Prior to UAV recovery, the robot arm is positioned such that the capture mechanism is over the side of the ship and above the level of the deck. Using the sensed position of the UAV relative to the capture mechanism, the UAV is commanded along a flight path that passes below the capture mechanism such that the arresting hook would snag the arresting line. If there is wave-induced ship motion, the robot arm is commanded to compensate for the motion, holding the capture mechanism stable from the perspective of a UAV approaching from directly behind, or directly in front, of the mechanism. The robot arm controller relies on inputs provided by a ship motion sensor in order to provide the ship motion compensating commands to the robot arm actuators. If there is error relative to the commanded flight path, such as from wind-induced buffeting of the UAV, the capture mechanism is rotated via commands from the robot arm controller to compensate for the rapid vertical perturbations of the UAV about its commanded flight path during the final seconds prior to capture. To provide this compensation, the robot arm controller relies on input from the UAV position sensing system. This function is analogous to a baseball catcher adjusting his mitt for observed errors in ball trajectory relative to the requested pitch. Thus, prior to capture, the robot arm provides a stable target for the UAV regardless of ship motion and the capture mechanism provides automatic compensation of vertical flight path errors. A byproduct of the approach for compensating for UAV height variations is that residual vertical positioning errors of the capture mechanism by the robot arm may also be compensated.
[0011] When the approaching UAV reaches the capture mechanism, the hook snags a horizontal segment of the arresting line that is held between two posts. This horizontal segment is part of a loop that pulls away from the posts after the arresting hook snags the line. The hook in effect is lassoed by the arresting line. As the UAV continues its forward motion, the slack is taken up in the line and the line begins to unwind off of a winch drum that is coupled to the capture mechanism by a brake. The tension in the line provides the arresting force, bringing the UAV to rest. At the conclusion of the arrest sequence, the UAV is held suspended by its top hook on the arresting line, hanging in a near-normal attitude below the capture mechanism and above the water.
[0012] After arrest, the brake is released and a motor drives the winch drum causing the top hook with UAV immediately below to be hoisted up tightly against the capture mechanism into a restraining seat. All moving robot arm actuators are then brought to a stop, which, therefore, turns off the capture mechanism stabilization and allows the robot arm with attached UAV to move in concert with the ship. The robot arm is then commanded to place the UAV on the ship deck.
[0013] The ability of the recovery system to compensate for both ship motion and vertical position errors between the capture mechanism and the approaching UAV significantly facilitates the recovery of UAVs at sea. This ability reduces the challenges for the guidance and control system of the UAV and substantially increases the probability of successful recovery when seas are not calm. Calm seas are a rarity in realistic naval operations scenarios. In addition, the use of a robot arm and a top capture method facilitates the handling operations for the UAV after capture, which becomes especially important as the size of the UAV to be recovered increases beyond that easily managed by a single deck hand.
[0014] The present system can readily be mounted on ground vehicles and used for in-air recovery of UAVs above land when no runways or areas suitable for belly landings exist. Such ground vehicles can be moving or stationary. The system can also be used mounted on the ground. When used on stationary vehicles or on the ground, the arm stabilization function would not be activated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows the stabilized UAV recovery system mounted on the deck of a ship and about to capture a UAV.
[0016] FIG. 2 shows a top view of the ship with the recovery system mounted on the rear deck.
[0017] FIG. 3 shows the major components of the stabilized UAV recovery system.
[0018] FIG. 4 shows the robot arm holding the capture mechanism over the side of the ship prior to UAV capture.
[0019] FIG. 5 shows the joints and links of the robot arm.
[0020] FIG. 6 shows the wrist roll joint.
[0021] FIG. 7 shows commanded UAV flight path to a target point on the arresting line.
[0022] FIG. 8 shows the robot arm stabilizing the capture mechanism during large ship motions.
[0023] FIG. 9 shows the capture mechanism rotated in order to compensate for a vertical flight path error.
[0024] FIG. 10 shows elements of the capture mechanism that pertain to UAV arrest.
[0025] FIG. 11 shows a close-up view of the arresting line pulled against the stem.
[0026] FIG. 12 shows the capture mechanism during UAV arrest.
[0027] FIG. 13 shows the hoisting and transfer of the captured UAV to the ship deck.
DETAILED DESCRIPTION
[0028] FIG. 1 depicts the stabilized UAV recovery system in accordance with the illustrative embodiment of the present invention. In the illustrative embodiment, UAV recovery system 100 is mounted to deck 105 of a ship to recover UAV 110 at sea. FIG. 2 shows the relative location of UAV recovery system 100 on ship 200 . In some other embodiments, the UAV recovery system, with some modification, is mounted to a ground vehicle and used to recover UAVs over land.
[0029] FIG. 3 depicts the major components of the UAV recovery system 100 . These components include computer-controlled robot arm 300 and capture mechanism 305 . In a fashion similar to aircraft arrest systems on aircraft carriers, capture mechanism 305 presents arresting line segment 310 , which is held horizontally, to incoming UAV 110 that is snagged by arresting hook 315 mounted to UAV 110 . Arresting line segment 310 is held between two curved posts 320 of the capture mechanism. In contrast to aircraft arrest systems on aircraft carriers, however, there are no loads applied to the UAV structure via landing wheels and the primary recovery loads exerted on the UAV structure are through arresting hook. In the present embodiment of the invention, an arresting hook mounted to the top-side of the UAV (i.e., a roof hook) is assumed.
[0030] FIGS. 4A and 4B show robot arm 300 holding capture mechanism 305 over the side of the ship prior to capture. Robot arm 300 holds capture mechanism 305 such that the arresting line segment 310 is perpendicular to commanded flight path 400 . This is the optimal orientation for capture. In FIG. 4A commanded flight path 400 is parallel to the ship direction and in FIG. 4B commanded flight path 400 is not parallel to the ship direction.
[0031] The function of the robot arm prior to and during UAV capture is to properly position the capture mechanism while reducing greatly the risk of collision between the UAV and robot arm. To provide this function, a variety of kinematic arrangements of links and joints may be used for the robot arm. In the illustrative embodiment, a kinematic arrangement similar to that of the arm of a backhoe is employed. FIG. 5 depicts the major joints and links for the robot arm. These joints are shoulder 500 , elbow 505 , and wrist 510 . Shoulder 500 is a compound revolute joint that comprises a slew joint, which permits rotation about an axis perpendicular to deck 105 , and a pitch joint, which permits rotation about an axis parallel to deck 105 . Elbow 505 and wrist 510 are both revolute joints whose axes of rotation are each parallel to the shoulder pitch axis of rotation. The links include upper arm 515 , forearm 520 , and last link 525 . All joints are actuated and are under computer control. Design and construction techniques used for man lift devices would generally be appropriate for the robot arm. In contrast to typical man lift devices, however, some of the actuators need to be servo controlled. Specifically, the actuators for the shoulder pitch, elbow, and wrist need to be servo controlled so that the stabilization function described below can be performed. The techniques to design and construct a robot arm with said servo controlled actuators will be known by those skilled in the art. As depicted in FIG. 6 , capture mechanism 305 is attached to last link 525 of the robot arm and is coupled to it by wrist roll joint 600 , which allows the capture mechanism to rotate about the longitudinal axis of the last link of the robot. The wrist roll joint is actuated by a servo controlled actuator and is controlled by the robot arm computer.
[0032] During calm seas, there is no wave-induced ship motion. Furthermore, if the ship heading and forward speed are constant, then the ship will be fixed in an inertial reference frame, which is called the hydrodynamic reference frame. Under these conditions, once the robot arm deploys the capture mechanism for UAV capture, the robot arm joints are then held stationary, which holds the capture mechanism fixed in the hydrodynamic frame and, consequently, fixed with respect to the ship. To begin the recovery operation, the UAV is commanded to follow a flight path that is fixed in the hydrodynamic frame of reference and that ends at the capture mechanism as shown in FIG. 7 . Commanded flight path 400 is specified such that arresting hook 315 hits target point 700 when UAV 110 traverses the commanded flight path with no error. Target point 700 is selected as the midpoint of arresting line segment 310 .
[0033] If seas are not calm, the ship will be undergoing wave-induced motions in six degrees of freedom with respect to the hydrodynamic reference frame and the ship therefore would no longer be fixed in an inertial reference frame. With the ship undergoing wave-induced motion, commanding the UAV to the capture mechanism would become much more difficult if the robot arm actuators are held stationary since the capture mechanism would now be in a non-inertial frame of reference. The UAV control problem can be greatly facilitated by controlling the robot arm actuators such that the capture mechanism is held stable in the hydrodynamic reference frame. By relying on a motion sensor such as an inertial measurement unit (IMU) mounted to the ship, the robot arm control computer can generate the proper actuator commands to stabilize the capture mechanism in the hydrodynamic reference frame. The control algorithms to achieve stabilization control will be known by those skilled in the art of robot arm control. By stabilizing the capture mechanism, the method for controlling the UAV is equivalent to that used in calm seas. That is, the commanded flight path can still be specified in the hydrodynamic reference frame. Now, because the present embodiment of the robot arm has less than six degrees of freedom, the robot arm is in fact not capable of fully stabilizing the capture mechanism in inertial space. The arm is capable, however, of keeping the target point on the commanded flight path for the UAV. In fact, only three joints of the robot arm—the shoulder pitch, elbow, and wrist—need to be actively controlled to achieve this. The shoulder slew can be held stationary. FIG. 8 illustrates robot arm 300 stabilizing capture mechanism 305 while ship 200 is undergoing large motions. Although other embodiments of the invention could achieve full stabilization of the capture mechanism, this would result in higher mechanical and motion control complexity for the robot arm and would not lead to further simplification of the UAV control problem.
[0034] In order to command the UAV to traverse a flight path to the target point, a real-time estimate of the position of the UAV relative to the capture mechanism is required. This estimate can be provided by a variety of methods including relative GPS. Given this estimate, UAV control commands can be calculated and executed by the UAV flight controller thus guiding UAV 110 to target point 700 . Alternatively, the UAV can be flown by a human operator to the target point using video provided by a camera mounted on the UAV. Sensor technology to provide this UAV position estimate does exist and has been implemented for net-based shipboard UAV recovery.
[0035] The UAV will not follow exactly the path along which it is commanded. Flight path errors, especially in the vertical direction, can be introduced by wind buffeting. The capture mechanism passively compensates for horizontal flight path errors since arresting hook 315 may hit arresting line segment 310 anywhere between posts 320 . The arresting hook also provides some passive compensation for vertical flight path errors since the arresting hook will in general snag the arresting line if initial contact is made by the arresting line anywhere along the body of the arresting hook. If additional compensation for the vertical flight path error is required, this can be achieved by actuating wrist roll joint 600 such that the vertical height of arresting line segment 310 matches the vertical height of arresting hook 315 . FIG. 9 shows capture mechanism 305 rotated so that predicted actual flight path 900 , which differs in height from commanded flight path 400 , intersects arresting line segment 310 . If there were no flight path error, then capture mechanism 305 would be rotated such that arresting line segment 310 would contain target point 700 . In order to provide this active compensation, however, it is necessary to sense the height of the UAV in the final seconds before capture. This sensing can be achieved by a variety of sensing technologies including computer vision, radar, and LADAR. Candidate mounting locations for this sensor include last link 525 and capture mechanism 305 . The sensed height input is provided to the robot arm control computer, which computes the height of the predicted actual path and then sends the proper commands to the wrist roll actuator such that the arresting line segment tracks the height of the predicted actual path 900 . Sensor technology to provide this UAV position estimate does exist and has been implemented for net-based shipboard UAV recovery.
[0036] An important feature of the present embodiment of the invention is that robot arm actuators are not involved in the active flight path error compensation. The robot arm actuators compensate for ship motion only whereas the wrist roll actuator on the capture mechanism compensates for vertical flight path errors, which in general are higher in frequency than ship motion. The shoulder pitch of shoulder 500 , elbow 505 , and wrist 510 are actuated such that last link 525 is held approximately stable whereas wrist roll 600 is actuated such that height of arresting line segment 310 tracks the height of the UAV. Thus, anticipated ship motion must be taken into consideration for the design of the robot arm and anticipated flight path error characteristics must be taken into consideration for the design of the wrist roll actuator.
[0037] Once the arresting hook snags the arresting line, then the capture mechanism must bring the UAV to rest. FIG. 10 illustrates aspects of capture mechanism 305 that pertain to the arresting function. Capture mechanism 305 is shown in its configuration prior to UAV capture. Arresting line segment 310 belongs to arresting line loop 1000 and the remainder of the arresting line is attached to arresting line loop 1000 at splice 1005 . Starting at splice 1005 , the remainder of the arresting line is reeved through sheave 1010 and sheave 1015 and then wrapped on winch drum 1020 such that the loop is pulled tight against stems 1025 at the end of posts 320 . Sheave 1015 is attached to the rod of linear shock absorber 1030 , which is used for both holding a tension in the arresting line prior to capture and snatch load mitigation at the start of UAV arrest. Winch drum 1020 is coupled to a brake that is engaged prior to capture thus maintaining tension in the arresting line so that it remains pulled against stems 1025 . FIG. 11 shows a close-up view of the arresting line loop 1000 pulled against stem 1025 .
[0038] FIG. 12 shows the arrest sequence. FIG. 12A shows initial contact between arresting hook 315 with arresting line segment 310 . As UAV 110 continues forward motion, the arresting hook pushes the arresting line loop 1000 off of stems 1025 after which the arresting line becomes momentarily slack. FIG. 12B shows arresting line loop 1000 snagged in arresting hook 315 while the arresting line is slack. As UAV 110 continues its forward motion, the slack arresting line will pull tight at which point shock absorber 1030 extends its rod with attached sheave 1015 thus mitigating snatch loading. UAV arrest begins once the arresting line is pulled tight. FIG. 12C shows UAV 110 as it is arrested by pulling line off of winch drum 1020 with brake engaged. As the winch drum is rotating and paying out line, the brake remains engaged providing a constant torque, which results in a constant tension in the arresting line and hence constant magnitude arresting force applied to the UAV. FIG. 12D shows UAV 110 at rest under capture mechanism 305 and above the water. When the UAV is at rest under the capture mechanism, the tension in the line will equal the weight of the UAV with the brake providing the requisite torque to prevent winch drum rotation.
[0039] FIG. 13 shows operations of UAV recovery system 100 after the UAV 110 is captured. FIG. 13A shows UAV 110 suspended below the capture mechanism. FIG. 13B shows UAV 110 hoisted up to capture mechanism 305 by rotating winch drum 1010 with a winch motor. Capture mechanism 305 has been rotated via wrist roll 600 prior to the hoisting of UAV 110 in order that posts 320 are clear of UAV 110 when it is hoisted up. With the UAV hook hoisted up tightly to a seat in the capture mechanism, stabilization can be turned off. FIG. 13C shows UAV recovery system 100 placing UAV 110 on deck 105 .
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A stabilized UAV recovery system is disclosed. In the illustrative embodiment for UAV recovery over water, the system includes ship-based elements and UAV-based elements. The ship-based elements include a robot arm that holds a capture mechanism over the side of the ship while compensating for wave-induced ship motion. The UAV-based elements include a hook mounted to the top of the UAV fuselage. With the capture mechanism held stable from the perspective of a UAV approaching from behind or in front of the mechanism, the UAV is flown under it, snagging an arresting line with the hook. With continued forward motion of the UAV, the arresting line pulls out of a winch drum that is coupled to a brake, bringing the UAV to rest.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to swivel locking devices for stroller wheel, in particular to swivel locking devices for stroller wheel having a simple structure, easy to manipulate, and automatically orientatable.
2. Related Art
Strollers usually have wheels rotatably attached to the stem of the frame so as to freely rotate around the stem with respect to the frame by 360° in order to manipulate and change the traveling direction of the strollers conveniently. In addition, disposition of wheel swivel locking device between the stem of the frame and the wheels of the strollers is also known, such that the wheels may be switched from a state of being able to rotate around the stem into a state of being unable to rotate around the stem as needed and/or desired. For instance, U.S. Pat. No. 5,351,364 and U.S. Pat. No. 5,975,545 disclose examples of conventional swivel locking devices for stroller wheel. However, these conventional swivel locking devices are flawed in structural complexity, inconvenient manipulation, and incapability of automatic orientation.
SUMMARY OF THE INVENTION
Hence, an object of the present invention is to provide an swivel locking device for stroller wheel which has a simple structure and is easy to manipulate and automatically orientatable.
The swivel locking device for stroller wheel according to an embodiment of the present invention includes a seat, a wheel bearing assembly, a locking pin, a biasing member, and an operating member. The seat and the wheel bearing assembly are coupled so as to rotate with respect to each other. The locking pin is disposed on the wheel bearing assembly so as to move between a first position where the locking pin is coupled to the seat and the wheel bearing assembly is unable to rotate around the seat and a second position where the locking pin is decoupled to the seat to allow the rotation between the seat and the wheel bearing assembly. Normally, the biasing member biases the locking pin to the first position. The operating member is coupled to the wheel bearing assembly so as to move between a locked position and a unlocked position. The operating member is operatively coupled to the locking pin, such that movement of the operating member toward the locked position causes the locking pin to move toward the first position under biasing force of the biasing member, and the movement of the operating member toward the unlocked position causes the locking pin to move toward the second position against the biasing force of the biasing member.
Preferably, the locking pin includes: a first portion coupled to the biasing member in the wheel bearing assembly and capable of being coupled to the seat, and a second portion extending from the first portion to the outside of the wheel bearing assembly for being operatively coupled to the operating member.
Preferably, the second portion of the locking pin extends horizontally to the outside of the wheel bearing assembly, and the operating member abuts against the second portion of the locking pin.
Preferably, the operating member includes a horizontal portion to be coupled to the locking pin in the wheel bearing assembly.
Preferably, the locking pin includes a window, and the horizontal portion of the operating member passes through the window and the biasing member is disposed within the wheel bearing assembly between the operating member and the locking pin.
Preferably, in the swivel locking devices according to the aforementioned embodiments, a positioning slot is disposed in the seat. The locking pin is held on the first position by the partly locking pin inserted into the positioning slot, and the locking pin completely exits the positioning slot when the locking pin is on the second position.
Preferably, in the swivel locking devices according to the aforementioned embodiments, a bump is disposed on one of the operating member and the wheel bearing assembly, and a recess is disposed on the other one of the operating member and the wheel bearing assembly, when the bump is engaged with the recess, the locking pin is retained on the second position.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the wheel bearing assembly comprises a wheel bearing and a base coupled to the wheel bearing, the seat and the base are coupled so as to rotate with respect to each other, and the operating member is movably coupled to the base.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the wheel bearing assembly further includes a shock absorber disposed between the wheel bearing and the base.
Preferably, in the swivel locking devices according to the aforementioned embodiments, a trench for receiving the biasing member and partial locking pin has an opening near a front edge of the wheel bearing assembly, the opening is spaced communication in the front and the top side of the front edge.
Preferably, in the swivel locking devices according to the aforementioned embodiments, a cavity is formed on the base for receiving the seat, and a clasping mechanism is disposed in the cavity for restricting movement of the seat along an axis of the cavity.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the locking pin is coupled to the biasing member mounted within the trench.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the seat includes a mounting portion coupled to the wheel bearing assembly and a rim formed above the mounting portion, the rim includes two partitioning walls to define the positioning slot.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the operating member includes a pair of arms pivotably coupled to both sides of the wheel bearing assembly respectively, and a manipulating portion connected between the pair of arms so as to extend away from the wheel bearing assembly and operatively coupled to the locking pin.
Preferably, in the swivel locking devices according to the aforementioned embodiments, a pair of bumps are disposed on the pair of arms of the operating member and a pair of first recesses and a pair of second recesses are disposed on the wheel bearing assembly to selectively engage with the pair of bumps for holding the operating member in the first position and the second position respectively.
Preferably, in the swivel locking devices according to the aforementioned embodiments, the swivel locking devices further include a stopping mechanism for preventing the operating member from outrunning the locked position while the operating member is pivoted upwardly relative to the wheel bearing assembly.
The swivel locking device for stroller wheel according to another embodiment of the present invention includes a seat, a wheel bearing assembly, a locking pin, a biasing member, and an operating member. The wheel bearing assembly is rotatably coupled to the seat. The locking pin is mounted on a trench of the wheel bearing assembly and movable between a first position where the locking pin is coupled to the seat and the wheel bearing assembly is unable to rotate relative to the seat and a second position where the locking pin is decoupled to the seat to allow the wheel bearing assembly rotate relative to the seat freely. The biasing member is mounted within the trench of the wheel bearing assembly and normally biases the locking pin to the first position. The operating member includes a pair of arms coupled to both sides of the wheel bearing assembly respectively, and a manipulating portion connected between the pair of arms. The manipulating portion has an horizontal portion. The biasing member is located between the locking pin and the horizontal portion. The operating member is pivoted relative to the wheel bearing assembly between a locked position where the locking pin is moved toward the first position and a unlocked position where the locking pin is moved toward the second position.
Preferably, the locking pin includes a window, and the horizontal portion of the operating member passes through the window and the biasing member is disposed within the wheel bearing assembly between the operating member and the locking pin.
To those skilled in the art, these and other objects, features, aspects, and advantages of the present invention will become apparent from the detailed descriptions of the preferred embodiments of the invention with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the swivel locking device for stroller wheel connected between the stem and the wheels of a stroller according to a preferred embodiment of the present invention, wherein the swivel locking device is in a locked state.
FIG. 2 is a schematic view of the swivel locking device shown in FIG. 1 .
FIG. 3 is an exploded view of the swivel locking device shown in FIG. 2 .
FIG. 4 is a bottom view of a seat of the swivel locking device shown in FIG. 3 .
FIG. 5 is a lateral sectional view of the swivel locking device shown in FIG. 2 , wherein the swivel locking device is in an unlocked state.
FIG. 6 is a front sectional view of the swivel locking device shown in FIG. 2 , wherein the swivel locking device is in the unlocked state.
FIG. 7 is a lateral sectional view of the swivel locking device shown in FIG. 2 , wherein the swivel locking device is in the locked state.
FIG. 8 is a front sectional view of the swivel locking device shown in FIG. 2 , wherein the swivel locking device is in the locked state.
FIG. 9 is a schematic view showing the swivel locking device for stroller wheels according to another preferred embodiment of the present invention, wherein the swivel locking device is in the locked state.
FIG. 10 is a schematic view of the swivel locking device shown in FIG. 9 .
FIG. 11 is an exploded view of the swivel locking device shown in FIG. 10 .
FIG. 12 is a back view of the locking pin, the operating member, and the biasing member of the swivel locking device shown in FIG. 11 .
FIG. 13 is a lateral sectional view of the swivel locking device shown in FIG. 10 , wherein the swivel locking device is in the locked state.
FIG. 14 is a lateral sectional view of the swivel locking device shown in FIG. 10 , wherein the swivel locking device is in the unlocked state.
FIG. 15 is a lateral sectional view of the swivel locking device shown in FIG. 10 , wherein the swivel locking device is switching from the unlocked state into the locked state.
DETAILED DESCRIPTION
Preferred embodiments of the present invention will be described in the following with reference to the accompanying drawings.
First Preferred Embodiment
First, referring to FIG. 1 , an swivel locking device 14 for stroller wheel coupled between a stem 10 of a stroller frame (not shown) and a pair of wheels 18 according to the preferred embodiment of the present invention is shown. The stem 10 is fixedly coupled to the swivel locking device 14 , and the pair of wheels 18 are rotatably installed on an axle (not shown) fixedly passing through the swivel locking device 14 . The swivel locking device 14 is switched between a locked state and an unlocked state, such that when the swivel locking device 14 is in the unlocked state, the pair of wheels 18 may rotate around the stem 10 along with a portion of the swivel locking device 14 , and when the swivel locking device 14 is switched into the locked state from the unlocked state, the pair of wheels 18 are locked and prohibited from rotating around the stem 10 . FIG. 1 shows the swivel locking device 14 in the locked state.
Since the stroller and the components thereof except the swivel locking device 14 according to the present invention are known in this field, the details thereof are omitted herein. In addition, it is apparent to those skilled in the art that the stroller can be of any kind, and the arrangement and amount of the stroller wheels are not limited to what shown here.
The structure of the swivel locking device 14 for stroller wheel according to a preferred embodiment of the present invention is described in detail below with reference to FIGS. 2 to 8 . As clearly shown in FIG. 3 , the swivel locking device 14 includes a wheel bearing assembly 20 , a seat 22 , an operating member 24 , a locking pin 26 , and a biasing member 28 . In this embodiment, the wheel bearing assembly 20 includes a wheel bearing 30 , a base 32 coupled to the wheel bearing 30 , and a shock absorber 34 disposed between the wheel bearing 30 and the base 32 .
The wheel bearing 30 includes an axle receiving portion 36 extending laterally, a supporting portion 38 integrally extending forward and upward from the axle receiving portion 36 , and a base coupling portion 40 formed on the supporting portion 38 opposite to the axle receiving portion 36 . A traverse non-circular axle hole 42 is disposed on the axle receiving portion 36 for receiving the axle (not shown) coupled to the wheels 18 . The axle coupled to the wheels 18 may be fixedly or rotatably received in the axle hole 42 . The supporting portion 38 is preferably formed with a hollow portion 44 with an opening facing up for receiving the shock absorber 34 . The base coupling portion 40 includes a traverse base coupling hole 46 for receiving a coupler (not shown) to couple the wheel bearing 30 to the base 32 .
The base 32 includes a body 48 , a cylindrical seat coupling portion 50 extending upward from the top of the body 48 , and a wheel bearing receiving portion 52 extending backward from the body 48 . As preferably shown in FIGS. 5 and 7 , the bottom of the body 48 and the interior of the wheel bearing receiving portion 52 are formed hollow and space communicated for receiving the partly wheel bearing 30 and the shock absorber 34 . Further, a pair of pivot holes 55 are disposed on sides in the vicinity of the rear of the wheel bearing receiving portion 52 for receiving a pivot pin (not shown) to pivotably couple the operating member 24 to the base 32 .
As will be further described, the body 48 of the base 32 includes an upright cylindrical cavity 51 extending from the seat coupling portion 50 into the body 48 for receiving a portion of the seat 22 . As preferably shown in FIGS. 6 and 8 , a pair of hooked clasps 53 are disposed on the bottom of the cavity 51 , which become a portion of the clasping mechanism for restricting the movement of the seat 22 along the axis of the cavity 51 when being received in the cavity 51 of the body 48 . A vertical trench 54 is disposed in the front portion of the body 48 opposite to the wheel bearing receiving portion 52 . The vertical trench 54 is formed with a lower closed end at the body 48 , and has an opening disposed in the vicinity of the front edge 56 and is spaced communication in the front and the top side of the front edge 56 . Further, the body 48 has a pair of flanges 60 protruding from the top edges on both sides of the body 48 , a pair of first recesses 62 below and separate from the pair of flanges 60 , a pair of second recesses 64 below and separate from the pair of first recesses 62 , and a pair of wheel bearing coupling holes 66 disposed on the bottom of the body 48 below and separate from the pair of second recesses 64 .
The seat 22 includes a substantially cylindrical mounting portion 70 , a stem coupling portion 72 capable of fixedly coupling to the stem 10 of the stroller frame, and a rim 74 substantially in an oval shape when being viewed from above formed between the mounting portion 70 and the stem coupling portion 72 . A stem receiving hole 75 is disposed on the mounting portion 70 for receiving the end portion of the stem 10 . As preferably shown in FIGS. 4 to 7 , the mounting portion 70 has a shape and a size capable of being received within the cavity 51 of the base 32 . The bottom of the mounting portion 70 includes a cylindrical clasping portion 76 protruding into the stem receiving hole 75 of the mounting portion 70 . The clasping portion 76 defines a clasping hole 78 allowing the pair of clasps 53 on the bottom of the cavity 51 in the base 32 to pass through. More specifically, the clasping portion 76 with the clasping hole 78 and the pair of hooked clasps 53 form a clasping mechanism for restricting the movement of the seat 22 along the axis of the cavity 51 when the seat 22 is installed in the cavity 51 .
As preferably shown in FIGS. 4 to 7 , the rim 74 of the seat 22 forms a capping trench 80 which has an opening facing down corresponding to the cylindrical seat coupling portion 50 of the base 32 . The shapes and sizes of the coupling portion 50 and the capping trench 80 are designed such that when the seat 22 is installed in the cavity 51 of the base 32 while the coupling portion 50 is inserted into the capping trench 80 , the seat 22 and the base 32 may rotate around the axis of the cavity 51 with respect to each other. Further, as preferably shown in FIGS. 4 and 7 , the rim 74 has a front portion 82 and a rear portion 88 opposite to the front portion 82 . The front portion 82 has a shape and a size that when the seat 22 is installed in the cavity 51 of the base 32 and rotates with respect to the base 32 such that the front portion 82 is right above the vertical trench 54 , the outer surface 84 of the front portion 82 is substantially even with the outer surfaces of the front edge 56 of the base 32 and the front walls 58 of the vertical trench 54 . Further, a positioning slot 86 communicating with the capping trench 80 and having an opening facing down is disposed on the front portion 82 of the rim 74 . The positioning slot 86 is defined by two partitioning walls 85 in the capping trench 80 and substantially extending backward from the inner surface of the front portion 82 of the rim 74 . The positioning slot 86 has a sectional profile and a size substantially corresponding to those of the vertical trench 54 of the base 32 . In addition, the position of the positioning slot 86 is designated so that only when the seat 22 is installed in the cavity 51 of the base 32 and rotates with respect to the base 32 such that the front portion 82 is right above the vertical trench 54 , the positioning slot 86 is exactly aligned and communicates with the vertical trench 54 . In other words, as long as the front portion 82 of the seat 22 is not above the vertical trench 54 , the positioning slot 86 is not aligned with the vertical trench 54 , and the top opening of the vertical trench 54 is at least partially closed by the bottom surface of the seat 22 .
The stem coupling portion 72 of the seat 22 extends upward on the rear 88 of the rim 74 . The stem coupling portion 72 includes a hole 90 for receiving a securing member (not shown) to fixedly couple the stem 10 whose end portion is received in the receiving hole 75 of the seat 22 .
The locking pin 26 basically includes a first upright portion 92 , a horizontal portion 94 extending horizontally from the bottom of the first upright portion 92 substantially perpendicular to the first upright portion 92 , a second upright portion 96 extending downward from the middle of the horizontal portion 94 substantially perpendicular to the horizontal portion 94 , and a third upright portion 98 extending downward from the bottom of the first upright portion 92 substantially parallel to the second upright portion 96 . The first upright portion 92 has a sectional profile and a size substantially corresponding to the sectional profiles and the sizes of the vertical trench 54 of the base 32 and the positioning slot 86 of the seat 22 . A substantially upright bar 91 is disposed on the rear of the first upright portion 92 facing the coupling portion 50 . The bar 91 may be received in the trench formed between two substantially upright bar 57 in front of the coupling portion 50 . The third upright portion 98 has a sectional profile which size is smaller than that of the first upright portion 92 .
In this embodiment, the biasing member 28 is a spring. As preferably shown in FIGS. 5 and 7 , the shape and size of the spring (biasing member) 28 is selected so as to be uprightly received in the vertical trench 54 of the base 32 .
In this embodiment, the operating member 24 is substantially U-shaped. The operating member 24 basically includes a pair of arms 100 extending in parallel with each other and a manipulating portion 102 connected between the pair of arms 100 on a pair of corresponding ends of the arms 100 . Each of the arms 100 includes a pivot hole 104 on the other end opposite to the manipulating portion 102 for receiving the pivot pin (not shown) in cooperation with the pivot holes 55 of the base 32 , so as to pivotally couple the operating member 24 to the base 32 . Each of the arms 100 includes stopping recesses 106 and bumps 108 below and separate from the stopping recesses 106 on the side facing the base 32 between the pivot hole 104 and the manipulating portion 102 . The stopping recesses 106 and the flanges 60 of the base 32 are formed to prevent the operating member 24 from moving upward, and the bumps 108 form an engaging mechanism along with the first recesses 62 and the second recesses 64 of the base 32 respectively for holding the operating member 24 with respect to the pivot position of the base 32 , as will be further described hereinafter. However, the shapes of the bumps 108 , the first recesses 62 , and the second recesses 64 are not limited herein. Also, the bumps 108 may be replaced with recesses while the first recesses 62 and the second recesses 64 may be replaced with bumps to form the engaging mechanism which holds the operating member 24 with respect to the pivot position of the base 32 .
As preferably shown in FIG. 2 , the curve of the inner surface of the manipulating portion 102 of the operating member 24 matches those of the front edge 56 of the body 48 of the base 32 and the front walls 58 of the vertical trench 54 , such that when the operating member 24 is pivotably coupled to the base 32 , the manipulating portion 102 of the operating member 24 extends outward away from the base 32 . Further, as preferably shown in FIGS. 5 and 7 , a recess 110 is disposed on the bottom of the manipulating portion 102 . The recess 110 abuts against the horizontal portion 94 of the locking pin 26 after the swivel locking device 14 is assembled.
The shock absorber 34 is made of a resilient material known in this field. The shock absorber 34 can be received in the hollow portion 44 in the supporting portion 38 of the wheel bearing 30 , the hollow portion on the bottom of the body 48 of the base 32 , and the hollow interior of the wheel bearing receiving portion 52 of the base 32 , so as to be disposed between the wheel bearing 30 and the base 32 . As preferably shown in FIGS. 5 and 7 , after the swivel locking device 14 is assembled, a portion of the shock absorber 34 directly contacts the bottom of the mounting portion 70 of the seat 22 installed in the cavity 51 by the breach formed on the bottom of the cavity 51 of the base 32 , whereby providing shock absorbing effect. In addition, it is apparent to those skilled in the art that the type and/or shape of the shock absorber are not limited to what shown here.
Upon assembly of the swivel locking device 14 , the shock absorber 34 is first partially received in the hollow portion 44 of the supporting portion 38 of the wheel bearing 30 . Then, the base 32 covers the wheel bearing 30 containing the shock absorber 34 , such that the exposed portion of the shock absorber 34 from the wheel bearing 30 and a portion of the supporting portion 38 and the base coupling portion of the wheel bearing 30 are contained in the hollow interior of the wheel bearing receiving portion 52 of the base 32 and the hollow portion on the bottom of the body 48 . Then, a connecting member (not shown) passes through a wheel bearing coupling hole 66 disposed on a side of the body 48 of the base 32 , base coupling holes 46 disposed on the base coupling portion 40 of the wheel bearing 30 , and another wheel bearing coupling hole 66 disposed on another sided of the body 48 of the base 32 in this order, whereby coupling the wheel bearing 30 to the base 32 .
As preferably shown in FIGS. 5 and 7 , the spring 28 is then uprightly received in the vertical trench 54 of the base 32 , such that the bottom of the spring 28 abuts against the lower closed end of the vertical trench 54 of the body 48 of the base 32 . The locking pin 26 is mounted above the spring 28 and is inserted into the vertical trench 54 such that the third upright portion 98 of the locking pin 26 is received in the winding of the spring 28 , the bottom of the first upright portion 92 and a portion of the bottom of the horizontal portion 94 abut against the top of the spring 28 , the horizontal portion 94 extends to the outside of the base 32 from an opening defined by the opposite front walls 58 of the vertical trench 54 , and the second upright portion 96 is substantially abutted against the front edge 56 of the base 32 .
The operating member 24 is then pivotably coupled to the base 32 by the pivot pin (not shown). More specifically, the pivot pin passes through one of the pivot holes 104 disposed on the arms 100 of the operating member 24 , then the pair of pivot holes 55 disposed on the wheel bearing receiving portion 52 of the base 32 , and finally the other pivot hole 104 disposed on the other arm 100 of the operating member 24 , whereby the operating member 24 is pivotably coupled to the base 32 . In addition, the front portion of the horizontal portion 94 of the locking pin 26 abuts against the recess 110 on the manipulating portion 102 of the operating member 24 . As a result, the downward pivot of the operating member 24 with respect to the base 32 may cause the locking pin 26 to move downward and compress the spring 28 , and the upward pivot of the operating member 24 with respect to the base 32 may remove the downward force applied on the locking pin 26 , such that the locking pin 26 is biased by the counterforce of the spring 28 .
Further, when the operating member 24 is pivotably coupled to the base 32 as preferably shown in FIGS. 6 and 8 , the stopping recesses 106 and the bumps 108 are disposed on the arms 100 of the operating member 24 corresponding to the flanges 60 , the first recesses 62 , and the second recesses 64 disposed on the body 48 of the base 32 . The bumps 108 of the operating member 24 and the first recesses 62 of the base 32 are defined as a first engaging mechanism for providing an upper limit position of the operating member 24 . That is, the operating member 24 may pivot upward with respect to the base 32 until the bumps 108 of the operating member 24 engage with the first recesses 62 of the base 32 so that the first engaging mechanism holds the operating member 24 in the upper limit position as shown in FIG. 8 . This upper limit position of the operating member 24 is defined as a locked position of the operating member 24 . When the operating member 24 is on the locked position, the swivel locking device 14 is in the locked state, such that the wheels 18 are locked and prohibited from rotating around the stem 10 , as will be further described hereinafter. Similarly, the bumps 108 of the operating member 24 and the second recesses 64 of the base 32 are defined as a second engaging mechanism for providing a lower limit position of the operating member 24 . That is, the operating member 24 may pivot downward with respect to the base 32 until the bumps 108 of the operating member 24 engage with the second recesses 64 of the base 32 so that the second engaging mechanism holds the operating member 24 on this lower limit position as shown in FIG. 6 . This lower limit position of the operating member 24 is defined as an unlocked position of the operating member 24 . When the operating member 24 is on the unlocked position, the swivel locking device 14 is in the unlocked state, such that the wheels 18 are released to freely rotate around the stem 10 , as will be further described hereinafter.
Further, the stopping recesses 106 disposed on the arms 100 of the operating member 24 and the flanges 60 of the body 48 of the base 32 are defined as a stopping mechanism for preventing the operating member 24 from outrunning the locked position due to over-bias by the user. That is, as preferably shown in FIG. 8 , when the operating member 24 pivots upward with respect to the base 32 until the bumps 108 of the operating member 24 engage with the first recesses 62 of the base 32 , the flanges 60 of the base 32 engage with the stopping recesses 106 of the operating member 24 , thereby the operating member 24 is prevented from continuing to pivot upward.
Then, the mounting portion 70 of the seat 22 is inserted into the cavity 51 of the base 32 and the coupling portion 50 of the base 32 being inserted into the capping trench 80 of the seat 22 , until the hooked clasps 53 formed on the bottom of the cavity 51 pass through the clasping hole 78 formed on the bottom of the mounting portion 70 to clasp the clasping portion 76 . Thus, the seat 22 is mounted on the base 32 such that the seat 22 and the base 32 may rotate around the axis of the cavity 51 with respect to each other but the movement of the seat 22 along the axis of the cavity 51 is restricted. During assembly of the seat 22 , the operating member 24 may pivot downward to the unlocked position so as to overcome the biasing force of the spring 28 to bias the locking pin 26 , whereby preventing the first upright portion 92 of the locking pin 26 from interfering the assembly of the seat 22 . Alternatively, the front portion 82 of the rim 74 of the seat 22 may be ensured to be right above the vertical trench 54 of the base 32 during assembly of the seat 22 , so that the positioning slot 86 with an opening facing down disposed on the front portion 82 is exactly aligned and communicates the vertical trench 54 . As a result, the first upright portion 92 of the locking pin 26 on the spring 28 in the vertical trench 54 may be smoothly inserted into the positioning slot 86 during the assembly of the seat 22 without any interference.
After completion of the assembly of the swivel locking device 14 as mentioned above, the end of the stem 10 may be inserted into the stem receiving hole 75 of the seat 22 , and a securing member (not shown) may pass through the hole 90 of the stem coupling portion 72 of the seat 22 and a corresponding hole (not shown) formed on the stem 10 , thereby the stem 10 is fixedly coupled to the seat 22 . Finally, the wheels 18 may be rotatably installed on the axle fixedly passing through the axle hole 42 of the axle receiving portion 36 of the wheel bearing 30 .
Hereinafter, the operation of the swivel locking device 14 according to a preferred embodiment of the present invention is described in detail mainly with reference to FIGS. 5 to 8 . FIGS. 7 and 8 show the swivel locking device 14 in the locked state. When the swivel locking device 14 is in the locked state, as shown in FIG. 8 , the operating member 24 is held on the locked position by the first engaging mechanism formed by the bumps 108 of the operating member 24 along with the first recesses 62 of the base 32 and the stopping mechanism formed by the stopping recesses 106 of the operating member 24 along with the flanges 60 of the base 32 . Also, when the swivel locking device 14 is in the locked state, as shown in FIG. 7 , the locking pin 26 is biased to a first position by the spring 28 . More specifically, when the locking pin 26 is on the first position as shown in FIG. 7 , the horizontal portion 94 of the locking pin 26 extending from the vertical trench 54 to the outside of the base 32 abuts against the recess 110 on the bottom of the manipulating portion 102 of the operating member 24 held on the locked position, and the top of the first upright portion 92 of the locking pin 26 enters the positioning slot 86 of the rim 74 of the seat 22 and the swivel locking device 14 is retained on the locked state. As the locking pin 26 extends from the vertical trench 54 of the base 32 into the positioning slot 86 of the seat 22 , since the movement of the locking pin 26 on the first position is restricted by the two partitioning walls 85 in the capping trench 80 of the seat 22 , the locking pin 26 prevents the seat 22 and the base 32 from rotating with respect to each other, and the seat 22 and the wheel bearing assembly 20 including the base 32 , the shock absorber 34 , and the wheel bearing 30 are thus prevented from rotating with respect to each other. As a result, the wheels 18 coupled to the wheel bearing assembly 20 are locked and prohibited from freely rotating around the seat 22 and the stem 10 fixedly coupled to the seat 22 .
When a user desires the wheels 18 to be unlocked so as to freely rotate around the stem 10 , the user may apply a downward force to the upper surface of the manipulating portion 102 of the operating member 24 held on the locked position by hand or foot, so as to overcome the holding force of the first engaging mechanism, such that the operating member 24 may pivot downward with respect to the base 32 . Since the horizontal portion 94 of the locking pin 26 on the first position abuts against the recess 110 of the operating member 24 on the locked position as described above, the downward pivot of the operating member 24 with respect to the base 32 may apply a downward pressure on the horizontal portion 94 of the locking pin 26 , whereby the upward biasing force of the spring 28 may be overcome to bring down the locking pin 26 and compress the spring 28 . The operating member 24 may pivot downward until the bumps 108 of the operating member 24 engage with the second recesses 64 of the base 32 . Meanwhile, the second engaging mechanism formed by the bumps 108 and the second recesses 64 as described above may hold the operating member 24 on this lower limit position, i.e., the unlocked position of the operating member 24 , as shown in FIG. 6 . When the operating member 24 is held on the unlocked position by the second engaging mechanism as shown in FIG. 5 , the locking pin 26 has been biased by the operating member 24 and is on the second position separate from the seat 22 . More specifically, when the locking pin 26 is on the second position separate from the seat 22 , as shown in FIG. 5 , the locking pin 26 may compress the spring 28 under the horizontal portion 94 abutting against the recess 110 of the operating member 24 , and the first upright portion 92 of the locking pin 26 is completely in the vertical trench 54 . That is, the locking pin 26 completely exits the positioning slot 86 of the rim 74 of the seat 22 and is completely separate from the seat 22 . Therefore, the seat 22 and the base 32 may rotate with respect to each other, and whereby the seat 22 and the wheel bearing assembly 20 including the base 32 , the shock absorber 34 , and the wheel bearing 30 may freely rotate with respect to each other. As a result, the wheels 18 may freely rotate around the stem 10 with respect to the stroller frame along with the wheel bearing assembly 20 .
When the user desires the wheels 18 to be locked so as not to freely rotate around the stem 10 , the user may apply an upward force to the lower surface of the manipulating portion 102 of the operating member 24 held on the unlocked position by hand or foot, so as to overcome the holding force of the second engaging mechanism, such that the operating member 24 may pivot upward with respect to the base 32 . Because as shown in FIG. 5 , the horizontal portion 94 of the locking pin 26 on the second position abuts against the recess 110 on the bottom of the operating member 24 on the unlocked position, the upward pivot of the operating member 24 with respect to the base 32 may release the force applied on the horizontal portion 94 of the locking pin 26 by the operating member 24 . Therefore, once the operating member 24 pivots upward and leaves the locked position, the locking pin 26 on the second position is spontaneously biased by the spring 28 under the counterforce of the compressed spring 28 and separate from the second position. The operating member 24 may, as described above, pivot upward until being held on the locked position as shown in FIGS. 7 and 8 . However, even the operating member 24 has been held on the locked position, if the front portion 82 of the seat 22 is not on the top of the vertical trench 54 of the base 32 , the positioning slot 86 of the seat 22 is not exactly aligned and communicates with the vertical trench 54 . Therefore, the top of the first upright portion 92 of the locking pin 26 is unable to enter the positioning slot 86 and is blocked by the bottom surface of the front portion 82 of the seat 22 , whereby the spring 28 is still compressed by the locking pin 26 . Meanwhile, if the seat 22 rotates with respect to the base 32 such that the front portion 82 of the seat 22 is on the top of the vertical trench 54 of the base 32 , whereby the positioning slot 86 of the seat 22 is exactly aligned and communicates with the vertical trench 54 , since the bottom surface of the seat 22 no longer blocks the top of the first upright portion 92 of the locking pin 26 , the locking pin 26 is spontaneously biased by the spring 28 under the counterforce of the compressed spring 28 , the top of the first upright portion 92 of the locking pin 26 therefore enters the positioning slot 86 of the seat 22 , causing the locking pin 26 to move to the first position automatically where the seat 22 is coupled as shown in FIG. 7 . This automatic swivel locking effect may conveniently lock the wheels 18 , such that the wheels 18 are prevented from freely rotate around the stem 10 .
Second Preferred Embodiment
Referring to FIG. 9 , which shows an swivel locking device 314 for stroller wheel coupled between a pair of wheels 318 according to another preferred embodiment of the present invention. Since the swivel locking device 314 is assembled with the stem and the wheels 318 in the same manner used for the swivel locking device 14 in the first preferred embodiment of the present invention, the descriptions thereof are omitted herein. In addition, the swivel locking device 314 shown in FIG. 9 is in the locked state.
The structure of the swivel locking device 314 for stroller wheel according to another preferred embodiment of the present invention will be described in detail with reference to FIGS. 10 to 15 . As clearly shown in FIG. 11 , the swivel locking device 314 basically includes a wheel bearing assembly 320 , a seat 322 , an operating member 324 , a locking pin 326 , and a biasing member 328 . In this embodiment, the wheel bearing assembly 320 basically includes a wheel bearing 330 , a base 332 coupled to the wheel bearing 330 , and a shock absorber 334 disposed between the wheel bearing 330 and the base 332 .
Since the wheel bearing 330 , the shock absorber 334 , and the seat 322 in this embodiment are similar to those in the first preferred embodiment of the present invention, the descriptions thereof are omitted herein. Also, the base 332 in this embodiment is similar to the base 32 in the first preferred embodiment of the present invention, except that the base 332 in this embodiment does not include the flanges 60 of the base 32 in the first preferred embodiment.
An upright portion 396 is extended downward from the bottom of the manipulating portion 402 of the operating member 324 , and is substantially abutted against the front edge of the base 332 . As preferably shown in FIG. 12 , the rear of the upright portion 396 of the operating member 324 includes a horizontal portion 403 extending backward, and the top of the horizontal portion 403 includes a stud 405 to be received in the hollow portion of the biasing member 328 , whereby the biasing member 328 is held. The arms 400 of the operating member 324 includes bumps 408 on the side facing the base 332 for selectively engaging with the first recesses 362 and the second recesses 364 of the base 332 . However, the shapes of the bumps 408 , the first recesses 362 , and the second recesses 364 are not limited herein. Also, the bumps 408 may be replaced with recesses while the first recesses 362 and the second recesses 364 may be replaced with bumps to achieve the purpose of holding the operating member 324 .
A substantially upright bar 391 is disposed on the rear of the locking pin 326 facing the base 332 , and the bar 391 may be received in a trench 354 between two substantially upright bars 357 . As preferably shown in FIG. 12 , the locking pin 326 has a window 393 . The window 393 extends downward from vicinity of the middle of the locking pin 326 to the bottom of the locking pin 326 and forms an accommodation space for receiving the biasing member 328 . As preferably shown in FIGS. 13 to 15 , the horizontal portion 403 of the operating member 324 passes through the window 393 of the locking pin 326 , such that the operating member 324 is operatively coupled to the locking pin 326 . The biasing member 328 is disposed within the vertical trench of the wheel bearing assembly 320 and between the operating member 324 and the locking pin 326 . The top end of the biasing member 328 is abutted against a closed end of the accommodation space of the locking pin 326 where is near the top wall of the window. Further, as shown in FIGS. 13 and 14 , the uncompressed height of the biasing member 328 is designed such that when the bumps 408 of the operating member 324 engage with the first recesses 362 of the base 332 , the locking pin 326 is biased by the biasing member such that the top of the locking pin 326 enters the positioning slot 386 formed in the seat 322 , and when the bumps 408 of the operating member 324 engage with the second recesses 364 of the base 332 , the biasing member 328 may have a most suitable height so that the locking pin 326 may completely exit the positioning slot 386 formed in the seat 322 .
Next, the operation of the swivel locking device 314 according to the second preferred embodiment of the present invention will be described with reference to FIGS. 13 to 15 and it is similar to the first preferred embodiment.
FIG. 13 shows the swivel locking device 314 in the locked state. When the swivel locking device 314 is in the locked state, the bumps 408 disposed on the operating member 324 may engage with the first recesses 362 of the base 332 to hold the operating member 324 on the locked position, and the locking pin 326 is biased by the biasing member 328 , such that the top of the locking pin 326 enters the positioning slot 386 formed in the seat 322 . Similar to the seat used in the first preferred embodiment of the present invention, since there are also two identical partitioning walls (not shown) in the seat 322 used herein for limiting the movement of the locking pin 326 , when the top of the locking pin 326 is in the positioning slot 386 , the locking pin 326 prevents the seat 322 and the base 332 from rotating with respect to each other, thereby preventing the seat 322 and the wheel bearing assembly 320 including the base 332 , the shock absorber 334 , and the wheel bearing 330 from rotating with respect to each other. As a result, the wheels 318 coupled to the wheel bearing assembly 320 are locked and unable to freely rotate around the seat 322 and the stem fixedly coupled to the seat 322 (not shown).
FIG. 14 shows the swivel locking device 314 in the unlocked state. When the user desires the wheels 318 to be unlocked so as to freely rotate around the stem, the user may bias the manipulating portion 402 of the operating member 324 held on the locked position, such that the operating member 324 may pivot downward with respect to the base 332 , whereby the bumps 408 of the operating member 324 engage with the second recesses 364 of the base 332 , i.e., the unlocked position of the operating member 324 . Because the locking pin 326 is supported by the biasing member 328 , and the biasing member 328 is held by a stud 405 disposed on the operating member 324 , when the operating member 324 pivots downward to the unlocked position, the biasing member 328 and the locking pin 326 may be caused to move downward, and the locking pin 326 may completely exit the positioning slot 386 formed in the seat 322 . As a result, the seat 322 and the base 332 may rotate with respect to each other, whereby the seat 322 and the wheel bearing assembly 320 including the base 332 , the shock absorber 334 , and the wheel bearing 330 may rotate with respect to each other. Therefore, the wheels 318 may freely rotate around the stem with respect to the stroller frame along with the wheel bearing assembly 320 .
When the user desires the wheels 318 to be locked so as not to freely rotate around the stem, the user may bias the manipulating portion 402 of the operating member 324 held on the unlocked position, such that the operating member 324 may pivot upward with respect to the base 332 to the locked position. However, as shown in FIG. 15 , even the operating member 324 has been held on the locked position, if the seat 322 does not rotate with respect to the base 332 to a proper position where the top of the locking pin 326 is not aligned with the positioning slot 386 formed in the seat 322 , the top of the locking pin 326 may be blocked by the bottom surface of the rim 374 of the seat 322 , whereby the biasing member 328 is compressed. In the meantime, if the seat 322 rotates with respect to the base 332 to a proper position where the top of the locking pin 326 is aligned with the positioning slot 386 , since the bottom surface of the rim 374 of the seat 322 no longer blocks the top of the locking pin 326 , the locking pin 326 may be immediately biased by the compressed biasing member 328 , such that the top of the locking pin 326 enters the positioning slot 386 and the base 332 is automatically locked relative to the seat 322 as shown in FIG. 13 . This automatic swivel locking effect may conveniently lock the wheels 318 so that the wheels 318 are prevented from freely rotating around the stem.
Although a few embodiments are given for detailed descriptions of the present invention, it is apparent to those skilled in the art that various change and modification are possible without departing from the spirit and the scope define by the claims of the present invention. In addition, the descriptions of the embodiments are for explanation but not for limitation of the scope defined by the claims and the equivalents of the present invention.
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A swivel locking device for stroller wheel, comprising: a seat, a wheel bearing assembly, a locking pin, a biasing member, and an operating member. The seat and the wheel bearing assembly are coupled so as to rotate with respect to each other. The locking pin may move between a first position where the seat is coupled to suppress rotation between the seat and the wheel bearing assembly and a second position where the seat is decoupled to allow the rotation between the seat and the wheel bearing assembly. Normally, the biasing member biases the locking pin to the first position. The operating member moves between a locked position and a unlocked position. Movement of the operating member toward the locked position causes the locking pin to move toward the first position. The movement of operating member toward the unlocked position causes the locking pin to move toward the second position.
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This is a continuation of application Ser. No. 635,452 filed July 30, 1984, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for preparing 1,2-amino alcohols.
2. Description of the Background Art
1,2-Amino alcohols (sometimes called beta-aminoalcohols) are compounds with an amino group and a hydroxyl group on adjacent carbon atoms. They are of considerable commercial importance, particularly in the pharmaceutical industry. Many 1,2-amino alcohols are important as drugs or as intermediates for the preparation of drugs (D. Lednicer and L. A. Mitscher, "The Organic Chemistry of Drug Synthesis", John Wiley and Sons, New York, 1977, pp. 62-84). Additionally, 1,2-amino alcohols are useful intermediates for the preparation of various heterocycles such as oxazolines (J. A. Frump, Chem. Rev., 71, 483 (1971)) or aziridines (I. Okado, K. Ichimura, R. Sudo, Bull. Chem. Soc. (Japan), 43, 1185 (1970)).
Of the several methods which have been developed for the preparation of 1,2-amino alcohols, few are general, versatile, provide high yields, or employ readily available starting materials.
A method for the synthesis of 1,2-amino alcohols which is similar to the process of the present invention has been reported in I. Elphimoff-Felkin, Bull. Soc. Chem. Fr., 784 (1955). In this method, the tetrahydropyranyl ether of a cyanohydrin, ##STR1## was reacted with a Grignard reagent, R'MgX, and then the intermediate product was reduced with lithium aluminum hydride (LiAlH 4 ). One shortcoming of this method is the necessity of first converting a ketone to its cyanohydrin, then converting this cyanohydrin to its tetrahydropyranyl ether. Both steps occur with varying degrees of efficiency, and yields are not uniformly high. A second shortcoming is that the reaction was not demonstrated to be general, i.e. applicable with essentially any ketone, since the only examples reported were with acetone, cyclopentanone, and cyclohexanone. The third shortcoming is that the only reducing agent which was demonstrated to be effective for reduction of the intermediate product was lithium aluminum hydride, LiAlH 4 , and its use provided only poor to moderate yield of product. In addition, lithium aluminum hydride is a hazardous reagent.
SUMMARY OF THE INVENTION
The present invention involves a process for producing 1,2-amino alcohols. The process comprises the steps of:
(1) reacting a silylated cyanohydrin compound with a Grignard reagent;
(2) treating the reaction product of Step 1 with either a reducing agent or an organolithium compound,
(3) hydrolyzing the reaction product of Step 2; and
(4) isolating the resulting 1,2-amino alcohol.
The method of the present invention results in formation of 1,2-amino alcohols in high overall yield and, generally, with fewer steps than with previously known synthetic methods. In addition, the present method is more general, being applicable with essentially any aldehyde or ketone starting material. Furthermore, with the method of this invention, the reduction of the intermediate reaction product can be accomplished with a variety of different reducing agents and is not limited to the use of lithium aluminum hydride. The process of this invention can also be used to prepare various mixtures of the 1,2-amino alcohol diastereomers. The versatility of being able to use different reducing agents or reducing step conditions or both in the present invention results in the production of diastereomeric products with the two stereoisomers in different ratios, an important feature because the individual diastereomers of a 1,2-amino alcohol often have very different physical and biological properties.
DETAILED DESCRIPTION OF THE INVENTION
Silylated cyanohydrins that are preferred for use in the process of this invention can be represented by the formula: ##STR2## wherein R 1 , R 2 , and R 3 can be the same or different and independently represent a member of the group consisting of hydrogen, alkyl groups, e.g., containing 1 to 6 carbon atoms, aralkyl groups, e.g. containing 7 to 12 carbon atoms, alkaryl groups, e.g. containing 7 to 12 carbon atoms, aryl groups, e.g., containing 6 to 14 carbon atoms, alkoxy groups, e.g., containing 1 to 6 carbon atoms, and
R 4 and R 5 independently represent a member of the group consisting of hydrogen, alkyl groups, e.g. containing 1 to 30 carbon atoms, aralkyl groups, e.g., containing 7 to 30 carbon atoms, alkaryl groups, e.g., containing 7 to 30 carbon atoms, aryl groups, e.g., containing 6 to 30 carbon atoms, or R 4 and R 5 , along with the carbon atom to which they are bonded, together represent a cycloalkyl group, e.g., containing 3 to 30 carbon atoms, said alkyl, cycloalkyl, aralkyl, alkaryl, and aryl groups of R 1 , R 2 , R 3 , R 4 , and R 5 being optionally substituted with various groups which are inert to the reaction conditions of step (1), e.g., alkoxy, aryloxy, alkaryloxy, aralkoxy, silyloxy, and halo.
Silylated cyanohydrin compounds useful in this invention are well-known in the art and can be prepared by reacting an aldehyde or ketone with a silyl cyanide, optionally in the presence of a catalyst. The reaction between the silyl cyanide and the aldehyde or ketone can take place in the absence or presence of solvent. Examples of solvents useful for the reaction are polar aprotic solvents, such as acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, or non-polar aprotic solvents such as benzene, toluene, chloroform, methylene chloride, hexane, pentane, and mixtures thereof. Solvents that are unsuitable for the reaction are those which would react with the silyl cyanide reactant or the silylated cyanohydrin product. These include water and alcoholic solvents. The reaction may be conducted in the presence of catalysts, such as zinc cyanide and zinc iodine, to hasten formation of the silylated cyanohydrin product.
Choice of the R 1 , R 2 , and R 3 groups is not particularly important since those groups are not retained in the final product. Preferred R 1 , R 2 , and R 3 groups are methyl, because the trimethylsilyl cyanide reagent is commercially available or can be formed in situ as described below.
Although the trimethylsilyl cyanide reagent used in this invention is commercially available, methods are known for generating the trimethylsilyl cyanide reagent in situ. J. K. Rasmussen and S. M. Heilmann (Synthesis, (1978), pp. 219-221) describe a method for synthesizing silylated cyanohydrins which involves reacting an aldehyde or ketone with chlorotrimethylsilane and potassium cyanide in a solvent such as acetonitrile or N,N-dimethylformamide. The reaction is accomplished by adding the carbonyl compound (0.1 mol) to a stirred suspension of potassium cyanide (0.3 mol) in solvent (20 ml), trimethylsilyl chloride (0.16 mol) and, optionally, zinc iodide (0.05 g). The mixture is refluxed gently and monitored by gas-liquid chromatography. On completion, the reaction mixture is filtered, the filter cake washed with dry solvent and filtered, and the combined filtrates concentrated in vacuo. Distillation at reduced pressure affords pure silylated cyanohydrins.
Representative examples of silylated cyanohydrins that are suitable for use in the process of this invention are the silylated cyanohydrins of cyclohexanecarboxaldehyde, butyraldehyde, benzaldehyde, p-anisaldehyde, p-tolualdehyde, m-dimethylaminobenzaldehyde, o-chlorobenzaldehyde, phenylacetaldehyde, pivaldehyde, pyridine-2-carboxaldehyde, p-nitrobenzaldehyde, cinnamaldehyde, crotonaldehyde, 7-methoxy-3,7-dimethyloctanal, phenylpropargylaldehyde, 9-anthraldehyde, 3-benzyloxy-4-methoxybenzaldehyde, 4-biphenylcarboxaldehyde, 2-fluorenecarboxaldehyde, p-fluorobenzaldehyde, 4-trimethylsilyloxybenzaldehyde, 2-naphthaldehyde, 1-pyrenecarboxaldehyde, ferrocenecarboxaldehyde, 2-furaldehyde, 5-methyl-2-thiophenecarboxaldehyde, l-perillaldehyde, 1,2,3,6-tetrahydrobenzaldehyde, acetylacetaldehyde dimethylacetal, 5-trimethylsilyloxy-2-pentanone, 5-chloro-2-pentanone, 4-dodecyloxybenzophenone, 9-heptadecanone, mesityl oxide, 3-methylthio-2-butanone, 10-nonadecanone, 2-adamantanone, dibenzosuberone, 4-chromanone, acetone, methyl ethyl ketone, cyclohexanone, camphor, acetophenone, benzophenone, deoxybenzoin, fluorenone, cyclododecanone, 3-cholestanone, and γ-chloro-p-fluorobutyrophenone.
Grignard reagents that are preferred for use in the process of this invention can be represented by the formula:
R.sup.6 MgX II
wherein
R 6 represents a member selected from the group consisting of alkyl groups, e.g., containing 1 to 30 carbon atoms, aralkyl groups, e.g., containing 7 to 30 carbon atoms, alkaryl groups, e.g., containing 7 to 30 carbon atoms, and aryl groups, e.g., containing 6 to 30 carbon atoms, said groups being optionally substituted with various groups which are inert to the reaction conditions of step (1), such as alkoxy, aryloxy, alkaryloxy, aralkoxy, silyloxy, and halo, and
X represents chloro, bromo or iodo.
Preparation of the Grignard reagent is well-known in the art and is discussed in detail in M. S. Kharasch and O. Reinmuth, Grignard Reactions of Nonmetallic Substances, Prentice-Hall, Englewood Cliffs, N.J. (1954), Chapter 2. In general, an organohalogen compound is allowed to react with magnesium in an anhydrous solvent to yield the organomagnesium halide, i.e., the Grignard reagent. Useful solvents for preparing Grignard reagents include benzene, toluene, diethyl ether, tetrahydrofuran, diisopropyl ether, and methyl t-butyl ether, with the ether solvents being preferred. The process for forming the Grignard reagent is generally exothermic; consequently, the organohalogen compound is generally dissolved in the solvent and added portion-wise or dropwise to the magnesium metal immersed in the same solvent such that mild refluxing of the solvent occurs, thus moderating the exothermicity of the reaction. The mixture can be heated for about 1 to 2 hours to ensure complete reaction of all the added organohalogen compound. The reaction mixture should then be allowed to cool to room temperature (about 25° C.) whereupon it can then be used directly in the process of the invention.
Representative examples of Grignard reagents that are suitable for use in the process of this invention are methylmagnesium chloride, ethylmagnesium iodide, ethylmagnesium bromide, n-propylmagnesium chloride, n-butylmagnesium chloride, n-hexylmagnesium bromide, tetramethylenedimagnesium dibromide, n-octylmagnesium chloride, phenylmagnesium bromide, p-chlorophenylmagnesium bromide, phenylmagnesium chloride, 9-phenanthrylmagnesium bromide, cinnamylmagnesium chloride, adamantylmagnesium bromide, 3-cholestanylmagnesium chloride, 1-tetradecylmagnesium bromide, 3-methylbenzylmagnesium chloride, 2-methoxyphenylmagnesium bromide, 3-(2-dioxolanyl)phenylmagnesium bromide, crotylmagnesium bromide, 4-hexadecylphenylmagnesium bromide, 11,11-dimethoxyundecylmagnesium bromide, 5-trimethylsilyloxypentylmagnesium iodide, 4-trifluoromethylphenylmagnesium bromide, 9,10-diphenyl-2-anthrylmagnesium chloride, vinylmagnesium chloride, and 2-thienylmagnesium iodide.
A preferred class of 1,2-amino alcohols produced by the process of this invention can be represented by the formula: ##STR3## wherein R 4 , R 5 , and R 6 are as defined above,
R 7 represents a member of the group consisting of hydrogen and R 8 wherein R 8 represents a member of the group consisting of alkyl groups, e.g., containing 1 to 30 carbon atoms, aralkyl groups, e.g., containing 7 to 30 carbon atoms, alkaryl groups, e.g., containing 7 to 30 carbon atoms, and aryl groups, e.g., containing 6 to 30 carbon atoms, said groups being optionally substituted with various groups which are inert to the reaction conditions of step (2), such as alkoxy aryloxy, alkaryloxy, aralkoxy, silyloxy, and halo, and
R 9 represents a member of the group consisting of hydrogen and R 10 CH 2 wherein a R 10 represents a member of the group consisting of alkyl groups, e.g., containing 1 to 20 carbon atoms, aralkyl groups, e.g., containing 1 to 12 carbon atoms, alkaryl groups, e.g., containing 1 to 12 carbon atoms, and aryl groups, e.g., containing 6 to 14 carbon atoms, said groups being optionally substituted with various groups which are inert to the reaction conditions of step (2), such as alkoxy, aryloxy, alkaryloxy, aralkoxy, silyloxy, and halo.
The reaction of the silylated cyanohydrin compound with the Grignard reagent can be accomplished by adding a solution of the silylated cyanohydrin compound to the Grignard reagent. It is preferred that the solution of silylated cyanohydrin compound be added dropwise to the Grignard reagent over a period of about one-half to one hour. The reaction, which is depicted by Equation (1) and is believed to result in the magnesium salt of the alpha-silyloxy imine is mildly exothermic-less so than the reaction wherein the Grignard reagent is prepared. Consequently, external cooling of the reaction mixture can usually be avoided. ##STR4## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are as defined above.
Solvents that are appropriate to dissolve the silylated cyanohydrin reactant are the solvents which are suitable for use in the preparation of the Grignard reagent. After the addition of the solution of the silylated cyanohydrin compound has been completed, the reaction mixture can be refluxed to ensure that all the silylated cyanohydrin has reacted. Preferably, the reaction mixture is refluxed for an additional 1 to 2 hours or stirred at room temperature for longer periods of times, e.g. 12 to 16 hours.
Though stoichiometric amounts can be used, generally, an excess of up to 200 mole percent of the Grignard reagent, with a preferred excess of up to 100 mole percent, and a more preferred excess of 5 to 25 mole percent, can be employed. Use of substantial excesses of Grignard reagent, i.e. greater than 25 mole percent, has been discovered to result in diminished yields and much more complicated reaction product mixtures.
Various reducing agents are suitable for the second step of the process of this invention. The following classes of reducing agents are preferred:
(a) hydride reducing agents such as metal aluminum hydrides, e.g. lithium aluminum hydride and lithium trialkoxyaluminum hydride, metal borohydrides, e.g. lithium, sodium, potassium, calcium and zinc borohydrides, sodium cyanoborohydride, borane, borane complexes with amines, e.g. tert-butylamine, diethylaniline, dimethylamine, N-ethylmorpholine, 2,6-lutidine, morpholine, N-phenylmorpholine, poly(2-vinyl pyridine), pyridine, triethylamine, and trimethylamine, borane complexes with sulfides, e.g. methyl sulfide and 1,4-oxathiane, borane complexes with phosphines, e.g. tri-n-butylphosphine, borane complexes with phosphites, e.g. triphenylphosphite, a borane complex with tetrahydrofuran, other boron reducing agents, e.g. 9-borabicyclo[3.3.1]nonane, disiamylborane, thexylborane, -isopinocampheyl-9-borabicyclo[3.3.1]nonyl hydride, sodium bis(2-methoxyethoxy)aluminum hydride, sodium diethyldihydroaluminate, and diisobutylaluminum hydride;
(b) hydrogen in the presence of a metal catalyst such as finely dispersed palladium, platinum, or Raney nickel;
(c) dissolving metals such as lithium, magnesium, potassium or sodium dissolved in an alcohol such as methanol or ethanol; and
(d) sodium dithionite.
A preferred reducing agent is sodium borohydride and the reduction step can be conveniently carried out by adding a solution of sodium borohydride in an alcohol such as methanol, ethanol, or propanol to the solution of the reaction product of Equation (1) at room temperature. However, the reduction may also be carried out at a lower temperature. It has been found that the temperature of the reduction influences the ratio of the diastereomers of the 1,2-amino alcohols. The diastereomeric ratio can be influenced by changing the reducing agent, for example by utilizing magnesium metal in methanol or zinc borohydride or lithium aluminum hydride instead of sodium borohydride as the reducing agent. It is often desirable to influence the diastereomeric ratio because, in the case of pharmaceuticals, one diastereomeric 1,2-amino alcohol may have very different physical and biological properties than the other diastereomer.
Additionally, further elaborated 1,2-amino alcohols can be prepared by adding an organolithium reagent, R 8 Li, to the reaction product of Equation (1), wherein R 8 is as previously defined. Representative examples of organolithium reagents that are suitable for use in the preparation of the further elaborated 1,2-aminoalcohols include methyllithium, n-butyllithium, phenyllithium, vinyllithium, hexadecyllithium, 4,4-dimethyl-2-lithiomethyl-2-oxazoline, and 4-methoxyphenyllithium. In this instance, the process may be illustrated by Scheme 1: ##STR5##
An amino alcohol with a substituent on nitrogen other than hydrogen where the substituent on nitrogen corresponds to a reduced carboxylic acid can also be prepared. This can be conveniently accomplished by adding a mixture of sodium borohydride and a carboxylic acid rather than sodium borohydride and an alcohol to the solution of the reaction intermediate from Equation (1). For example, if acetic acid is used, the N-ethyl amino alcohol is produced. It is well-known that many pharmaceutically important 1,2-amino alcohols have substituents other than hydrogen on nitrogen. In general, if a carboxylic acid having the formula R 10 CO 2 H is utilized in this step, R 9 of formula III is R 10 CH 2 wherein R 10 is as previously defined. Representative carboxylic acids of formula R 10 COOH which may be utilized include acetic acid, propionic acid, formic acid, butyric acid, pivalic acid, benzoic acid, trifluoroacetic acid, isobutyric acid, palmitic acid, monochloroacetic acid, stearic acid. If a carboxylic acid is not utilized in this step, then R 9 of formula III is hydrogen.
After either the reduction of intermediate from Equation (1) or the addition of an organolithium reagent to the intermediate from Scheme 1, hydrolysis to form the 1,2-amino alcohol can be effected by first adding an aqueous solution of an acid having a pKa of less than about 5 to the reaction mixture. Acids that can be used in this step of the process are hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, with hydrochloric acid being preferred. The mixture is then stirred, preferably at room temperature for a period of about one hour.
Isolation and recovery of the 1,2-amino alcohol product can be accomplished in several ways, the following being expedient. The aqueous acidic layer is separated from the organic layer of Step (3), and the organic layer is extracted with several additional portions of an aqueous acid solution. By the extraction procedure, the basic 1,2-amino alcohol product is separated from any non-basic side products from the reaction. The aqueous acid solutions are combined with the original aqueous acidic layer, and then to this combination an aqueous solution of sodium hydroxide, potassium hydroxide, or ammonium hydroxide is added to raise the pH of the original aqueous layer to about 8 to 10. In some cases this will cause the 1,2-amino alcohol to precipitate immediately, and it can then be isolated by simple filtration. In other cases, the 1,2-amino alcohol product does not precipitate immediately, but it can be isolated by means of extraction with a suitable organic solvent. As one example, the aqueous alkaline layer can be extracted with several portions of chloroform and the chloroform extracts combined. The chloroform can be removed from the combined extracts by evaporation, leaving the 1,2-amino alcohol product, usually in a very pure form. Further purification can be effected by distillation or recrystallizaton of the 1,2-amino alcohol product. In addition, the 1,2-amino alcohol can be converted to a salt by treatment with an acid, for example, hydrobromic, hydrochloric, maleic, or tartaric acid.
The invention can be further illustrated by the following non-limiting examples.
EXAMPLE 1
STEP 1
To a stirred solution of phenyl magnesium bromide was added dropwise a solution of 5.15 g (25 mmol) of the O-trimethylsilylated cyanohydrin of benzaldehyde dissolved in 75 mL of anhydrous diethyl ether. When the addition was complete, the reaction mixture was stirred overnight at room temperature.
STEP 2
A solution of 0.95 g (25 mmol) of sodium borohydride in 25 mL of methanol containing a few drops of a 10% solution of sodium hydroxide in water was added dropwise. The mixture was stirred for 3 hours at room temperature.
STEP 3
Then 100 mL of a 10% solution of hydrochloric acid in water was added and the mixture stirred for 1 hour. Diethyl ether (100 mL) was added.
STEP 4
The layers were separated, and the organic layer was extracted three times with 75 mL portions of a 10% aqueous hydrochloric acid solution. All the aqueous washings were combined and the pH adjusted to a value between 8 and 10 by the addition of about 300 mL of concentrated ammonium hydroxide solution. The white precipitate which formed was collected by filtration and dried. The aqueous filtrate was extracted with three 100 mL portions of chloroform. The combined chloroform extracts were washed with 75 mL of brine, dried over potassium carbonate, filtered, and evaporated to leave a white solid which was combined with the solid from the filtration to give 5.2 g (98%) of 2-amino-1,2-diphenyl ethanol as a 16:1 mixture of erythro and threo diastereomers as determined by 1 H-NMR.
The O-trimethylsilylcyanohydrin of benzaldehyde used in STEP 1 was prepared by the following method:
In a one liter, three-necked, round bottomed flask equipped with a mechanical stirrer, a reflux condenser fitted with a nitrogen-inlet tube, and a rubber septum were placed 97.5 grams (1.5 moles) of finely ground potassium cyanide (passed through a #30 sieve and dried at 115° C. at 0.5 torr for 24 hours), 100 mL of acetonitrile (dried over 4A molecular sieves), 81.4 grams (0.75 mole, 92.2 mL) of chlorotrimethylsilane, 53 grams (0.5 mole) of benzaldehyde and 0.5 gram (0.0004 mole) of zinc cyanide. The reaction was blanketed with dry nitrogen, stirring was begun, and the temperature raised to maintain gentle refluxing. After 21 hours, the reaction was complete, as evidenced by disappearance of benzaldehyde in the glpc analysis of a small sample taken from the reaction mixture. The reaction mixture was cooled and filtered with suction. The filter cake was washed twice with 50 mL of acetonitrile, and the combined filtrates were concentrated on a rotary evaporator. The residue was distilled at 93°-95° C. at 1.75 torr and weighed 84.0 grams (95% yield). The structure of the product was corroborated by spectral analyses.
Phenyl magnesium bromide used in STEP 1 was prepared by the following method:
Into a dry 500 ml, three-necked, round-bottomed flask equipped with a magnetic stirrer, argon inlet, addition funnel and condenser were placed 1.1 g (45 mg atom) of magnesium turnings and 10 mL of anhydrous diethyl ether. A solution of 5.5 g (35 mmol) of bromobenzene in 75 mL of anhydrous diethyl ether was added dropwise at such a rate that gentle refluxing of the solvent occurred. After the addition was complete, the solution was stirred for two hours.
EXAMPLES 2-6
The 1,2-amino alcohols listed in Table 1 and within the scope of formula III were obtained by the procedure described in Example 1.
TABLE 1______________________________________Example R.sup.4 R.sup.5 R.sup.6 R.sup.7 R.sup.9 Yield, %______________________________________2 CH.sub.3 CH.sub.3 C.sub.6 H.sub.5 H H 933 CH.sub.3 CH.sub.3 C.sub.6 H.sub.13 H H 804 CH.sub.3 CH.sub.3 c-C.sub.5 H.sub.9 H H 635 --(CH.sub.2).sub.5 --* CH.sub.3 H H 886 --(CH.sub.2).sub.5 --* C.sub.6 H.sub.5 H H 74______________________________________ *--(CH.sub.2).sub.5 -- along with the carbon atom to which it is bonded represents the cyclohexyl radical.
EXAMPLES 7-13
These examples indicate the influence of reducing agent and reduction temperature on the diastereomeric ratio of the 1,2-amino alcohols produced.
The 1,2-amino alcohols listed in Table 2 and within the scope of formula III were obtained by the procedure described in Example 1 except that the conditions of reduction were varied as indicated in Table 2.
TABLE 2__________________________________________________________________________ Reducing Temperature Yield Diastereomeric Ratio,*ExampleR.sup.4 R.sup.5 R.sup.6 R.sup.7 R.sup.9 Agent °C. % Erythro:Threo__________________________________________________________________________ 7 C.sub.6 H.sub.5 H C.sub.6 H.sub.5 H H LiAlH.sub.4 23 45 11.0 8 C.sub.6 H.sub.5 H C.sub.6 H.sub.5 H H Mg/CH.sub.3 OH 50 56 1.1 9 ##STR6## H CH.sub.3 H H NaBH.sub.4 23 85 4.310 ##STR7## H CH.sub.3 H H NaBH.sub.4 0 95 4.911 ##STR8## H CH.sub.3 H H NaBH.sub.4 -78 90 2412 ##STR9## H CH.sub.3 H H Zn(BH.sub.4).sub.2 23 96 7.313 ##STR10## H CH.sub.3 H H Zn(BH.sub.4).sub.2 -78 74 13.3__________________________________________________________________________ *Ratio determined by .sup.1 HNMR.
EXAMPLE 14
Preparation of 1-(3,4-dimethoxyphenyl)-2-ethylamino-propan-1-ol
By the procedure described in Example 1, 2.4 g (9.0 mmol) of the O-trimethylsilylated cyanohydrin of 3,4-dimethoxybenzaldehyde were reacted with 15 mmol of methylmagnesium iodide. To prepare the reducing agent, 2.5 g (68 mmol) of sodium borohydride was added to 25 mL of acetic acid in a separate reaction vessel, while the temperature of the solution was maintained below 20° C. This solution was then added dropwise to the reaction intermediate from the silylated cyanohydrin and Grignard reagent, and the mixture stirred for 5 hours. The solvent was then evaporated, 100 mL of diethyl ether and 25 mL of a 10% aqueous hydrochloric acid solution added to the residue, and the extractive work-up outlined in Example 1 was followed to yield 2.1 g of a gold semi-solid which was a 4:1 mixture of erythro and threo diastereomers of the desired N-ethylated amino alcohol, as determined by 1 H-NMR.
EXAMPLE 15
Preparation of 3-amino-2-methyl-3-phenyl-nonan-2-ol
By the procedure described in Example 1, 3.9 g (25 mmol) of the O-trimethylsilylated cyanohydrin of acetone were reacted with 27.5 mmol of n-hexylmagnesium bromide. To the reaction mixture was added 11.5 mL (27.5 mmol) of a solution of phenyllithium (2.4 molar in hexane-diethyl ether), and the mixture was stirred for 18 hours. Then 30 mL of a 10% aqueous hydrochloric acid solution were added and the extractive work-up of Example 1 was followed to yield 1.5 g of a white solid, mp. 64.5°-65.5° C.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.
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A process for the production of 1,2-amino alcohols, in improved yields, comprising the steps of:
(1) reacting a silylated cyanohydrin compound with a Grignard reagent;
(2) treating the reaction product of Step 1 with either a reducing agent, or an organolithium compound;
(3) hydrolyzing the reaction product of Step 2;
(4) isolating the resulting 1,2-amino alcohol.
The 1,2-amino alcohols thus formed are useful as pharmaceuticals or precursors therefor.
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This is a division of application Ser. No. 207,187 filed June 14, 1988, now U.S. Pat. No. 4,880,477.
THE FIELD OF THE INVENTION
The invention relates to improved, ductile cast iron, composition and a process of making ductile iron machine elements such as camshafts which are able to withstand high cyclical loading with a high resistance to wear for portions thereof in rolling contact with other machine elements.
BACKGROUND OF THE INVENTION
Camshafts of a roller-follower type for engines such as those used in automobiles must be able to withstand high cyclical (i.e. Hertzian) stresses with little wear. Until the advent of the present invention, only roller-follower camshafts made from steel could successfully be used for high Hertzian stress applications.
Austempered cast iron materials of high strength and high resistance to abrasion are known. For example, U.S. Pat. No. 3,549,431 to De Castelet, issued Dec. 22, 1970; U.S. Pat. No. 3,860,457 to Vuorinen et al., issued Jan. 14, 1975; U.S. Pat. No. 4,541,878 to Muehlberger et al., issued Sept. 17, 1985; U.S. Pat. No. 3,893,873 to Hanai et al., issued July 8, 1975; U.S. Pat. No. 3,549,430 to Kies, issued Dec. 22, 1970; U.S. Pat. No. 2,485,760 to Millis et al., issued Oct. 25, 1949; U.S. Pat. No. 2,324,322 to Reese et al., issued July 13, 1943; and U.S. Pat. No. 3,273,998 to Knoth, et al., issued Sept. 20, 1966, disclose austempered cast iron compositions. However, each of the processes disclosed fails to yield a form of cast iron which has a hardness suitable for machine elements in rolling contact such as roller-follower camshafts and which is prepared in a time-efficient manner to reduce overall manufacturing costs. Nor do these prior patents disclose an efficient means by which it is possible to selectively austemper portions of an article, thereby reducing overall costs and manufacturing time.
Grindahl discloses a cast iron article in the form of a gear that provides high resistance to wear. However, the Grindahl process includes the step of holding the article at an austenitizing temperature for a time preferably in the range of 3.5 hours. Grindahl's article also undergoes a cold-working step as part of the process.
De Castelet discloses a cast iron which is austempered at a temperature that yields a hardness too low for articles so made to resist wear when in rolling contact. In addition, although De Castelet discloses that articles may have portions thereof heat-treated, he does not disclose an efficient means to accomplish such localized heat treatment.
SUMMARY
According to the invention, a camshaft made by process comprises casting an elongated shaft from a cast iron composition including, by weight 3.40% to 3.90% (preferably 3.50% to 3.80%) carbon, 1.90% to 2.70% (preferably 2.10% to 2.40%) silicon, up to 1.40% (preferably up to 0.30%) manganese, up to 1.5% (preferably 0.20% to 0.60%) molybdenum, up to 0.08% (preferably up to 0.05%) phosphorus and up to 2.0% (preferably 0.08% to 1.20%) copper.
The elongated shaft has a plurality of eccentric lobes spaced therealong. At least some of the lobes in non-austempered condition are selectively heated to a temperature in the range of 1500°-2000 ° F. to austenitize only surface portions of the lobes while maintaining the remainder of the shaft in non-austempered condition. Thereafter the heated lobes are quenched rapidly to a bainite transformation temperature to essentially prevent the formation of pearlite in the heated lobe portions and the quenched lobe portions are held at the bainite transformation temperature for a time sufficient to transform at least a substantial portion of the austenite into bainite while avoiding the formation of pearlite. Thereafter the quenched lobe portions are cooled to room temperature to transform some of the remaining austenite to bainite or martensite. By this process, the camshafts are formed with selectively hardened lobes.
Further according to the invention, at least portions of the unhardened remainder of the shaft are machined subsequent to austempering the lobe portions. Portions of the austempered lobes are ground after the austempering process.
The austenitizing temperature is preferably in the range of 1420°-2100° F. and the austenitizing time is preferably in the range of 1 second to 100 seconds. Further, the lobes are preferably quenched to the bainite transformation temperature within 180 seconds. The bainite transformation temperature is in the range of 450°-850° F., preferably in the range of 465°-485° F. The lobes can be held at the bainite transformation temperature for a time in the range of 10 minutes to 240 minutes, preferably 115-125 minutes. The delay between the heating and quenching steps is less than 60 seconds, preferably less than 10 seconds. The camshaft is also preferably cooled in air from the bainite transformation temperature.
The austempered lobes comprise a microstructure comprising by volume 25% to 75% bainite, 5% to 50% martensite, 5% to 50% unreacted low carbon austenite, approximately 10% graphite nodules, and less than 1% cementite.
Other objects, features and advantages of the invention will be apparent from the ensuing description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic side elevational view of an engine pushrod valve gear mechanism having a roller lifter and including a roller-follower camshaft made with austempered ductile iron according to the present invention;
FIG. 2 is a perspective view of the camshaft of FIG. 1; and
FIG. 3 is a time-temperature diagram showing the preferred process of heat treatment for an austempered ductile iron material processed according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a roller follower camshaft 10 that is used in vehicles such as automobiles and having what are termed "roller lifter" engines. The camshaft comprises a body 12 and eccentric lobes 14.
The engine includes a pushrod valve gear mechanism 16 comprising a valve 18, valve spring 20, rocker arm 22, pushrod 24, roller follower 26, roller 28 and the camshaft 10. The roller 28 is rotatably mounted to the roller follower 26 and is in rolling contact with the camshaft lobe 14. The pushrod 24 is mounted to and between the roller follower 26 and a first side 30 of the rocker arm 22. The rocker arm is pivotally mounted with the valve 18 engaging a rocker arm second side 32. The valve is in registry with the engine cylinder head (not shown), so that reciprocating movement of the valve 18 will alternately open and close apertures (not shown) leading into the engine cylinder (not shown). Each cylinder of the engine has a plurality of associated valve gear assemblies.
As the camshaft 10 illustrated in FIG. 1 is rotated about its longitudinal axis by the engine, the camshaft lobe 14 initiates rotational motion in the roller 28. As the lobe eccentric portion 34 engages the roller, the roller follower 26 and pushrod 24 are driven upwardly relative to the figure. The pivoting action of the rocker arm 22 urges the valve downwardly as viewed in FIG. 1, thereby opening the aperture into the engine cylinder (not shown). This movement places the valve spring 20 in compression. As the lobe 14 continues to rotate and thereby to bring the lobe noneccentric portion 36 into engagement with the roller 28, the spring 20 will expand, driving the rocker arm 22 and valve 18 upwardly to thereby close the aperture. This opening and closing action completes one cycle for the valve gear mechanism 16. In an alternate embodiment (not shown), the follower 26 activates the valve 18 directly, without the use of a rocker arm.
Contact stress loads on the camshaft lobe 14 result primarily from the valve spring 20 expanding upwardly, causing the rocker arm 22 to urge the pushrod 24 downwardly and thereby cause the roller 28 to exert pressure on the camshaft lobe. This pressure induces cyclical stresses on the lobe 14 that, in conjunction with the rolling contact between the roller 28 and the lobe, causes the lobe to be susceptible to excessive wear. It is therefore important that the camshaft lobes 14 be made of a material that is highly resistant to wear when they are subjected to high cyclical (i.e., Hertzian) stresses. To perform successfully, the camshaft 10 must be able to withstand a Hertzian stress above 215,000 PSI. It has been found that a camshaft made of austempered ductile iron made according to the invention will meet this standard.
Austempering is a heat treatment wherein the iron alloy is: (1) heated to a temperature at which austenite forms (i.e., austenitizing the alloy); (2) quenched to an elevated temperature above which martensite forms; and (3) tempered at that temperature until a bainite microstructure comprising alternating layers of acicular ferrite and high carbon austenite is formed.
The austempered ductile iron according to the invention is preferably manufactured in the following manner. The iron comprises an alloy containing the following percentages of alloying elements by weight:
Carbon (C): 3.40-3.90 (preferably 3.50-3.80)
Silicon (Si): 1.90-2.70 (preferably 2.10-2.40)
Magnesium (Mg): 0.030-0.065 (preferably 0.035-0.055)
Manganese (Mn): 0.00-1.40 (preferably 0.00-0.30)
Molybdenum (Mo): 0.00-1.50 (preferably 0.20-0.60)
Phosphorus (P): 0.00-0.08 maximum (preferably 0.00-0.05)
Sulfur (S): 0.00-0.05 maximum (preferably 0.00-0.02)
Nickel (Ni): 0.00-3.00 maximum (preferably 0.00-0.10)
Copper (Cu): 0.00-2.00 maximum (preferably 0.80-1.20)
Chromium (Cr): 0.00-0.50 maximum (preferably 0.00-0.10)
Aluminum (Al): 0.00-0.10 (preferably none)
Titanium (Ti): 0.00-0.10 (preferably none)
Tin (Sn): 0.00-0.20 (preferably none)
Iron (Fe): the remainder
As seen in FIG. 3, to austemper the ductile iron, the alloy is heated to an austenitization temperature in the range of 1420° F. to 2100° F. (preferably 1500° F. to 2000° F.) for a period of one second to 8 minutes (preferably 30 seconds to 100 seconds for smaller articles and up to 8 minutes for larger articles). During this stage of the treatment, the microstructure of the article is transformed into austenite. The precise austenitization temperature is not critical because of the short time the article is in the austenitization range. After a delay of between zero seconds to 60 seconds (preferably one second to 10 seconds), the article is quenched in a salt bath comprising, for example, a mixture of sodium nitrite, sodium nitrate and potassium nitrate and tempered at a temperature in the range of 450° F. to 500° F. (preferably 465° F. to 485° F.). It is critical that the article avoid the pearlite knee shown in FIG. 3. If it enters the pearlite range, the strength, wear resistance and hardness of the article will be decreased. For this reason, the article must be quenched to the tempering temperature within 30 seconds to 180 seconds. An alternative quench medium may comprise an oil or a fluidized bed. The fluidized bed preferably includes a heated granular solid medium having a gas such as air blowing through the medium.
The article is tempered for a period between 10 minutes to 4 hours (preferably 115 minutes to 125 minutes). During this time, the article enters the bainite range, thereby transforming a portion of the microstructure into bainite. After tempering, the article is cooled by ambient air until it reaches a temperature of approximately 150° F. to 180° F. This typically takes 50 minutes to 60 minutes. Air cooling reduces the transformation of unreacted austenite into martensite. After the article reaches 150° F. to 180° F., it is placed in a water rinse having the same temperature. The water functions to rinse residual salt from the salt bath off the article. After rinsing, the article may be cooled by any convenient means such as air cooling to ambient temperature. Alternatively, for those applications in which the formation of martensite is not detrimental, forced air, an oil quench or a water quench can be used to cool the article after tempering.
As stated above, the microstructure obtained in the process comprises bainite (i.e., alternating layers of acicular ferrite and high carbon austenite). The microstructure also contains graphite nodules and can contain appreciable amounts of unreacted low carbon austenite (i.e. austenite that has not undergone the bainitic transformation) and martensite. The amounts of each microconstituent can vary widely depending upon austempering temperature, austempering cycle time and the chemical composition.
In the preferred embodiment for camshafts, the iron microstructure contains by volume, bainite in the range of 25% to 75%, unreacted low carbon austenite in the range of 5% to 50%, martensite in the range of 5% to 50% and graphite nodules in the range of approximately 10%. A small amount of carbide (cementite) may also be present from the original ductile iron microstructure. This phase is generally present in amounts less than 1%.
The advantage of camshafts formed of a ductile cast iron composition made according to this process is evident from stress and wear comparisons. A test fixture was fabricated to simulate engine operating conditions. Sample camshafts were installed in the test fixture and cycled at 545 revolutions per minute (RPM) through several 100,000-mile test simulations. Valve springs were used having loading characteristics which imposed a variety of stresses on the camshaft lobes. Tests of camshafts 10 made of austempered iron according to the invention will sustain Hertzian stresses of approximately 253 KSI without exceeding a 0.002-inch maximum lobe wear limitation. This endurance stress limit proved to be higher than those for camshafts made from either martensitic ductile iron or conventional 0.5% carbon steel alloys.
TABLE 1 shows a comparison of camshaft lobe wear for camshafts made of a variety of materials. The values are derived from the 100,000-mile simulation for a maximum valve spring loading force of 298.8 lbs. Because the stress imposed on each lobe is a function of the modulus of elasticity and the spring loading force, the stresses induced on the camshafts are different for iron and steel for a given spring loading. For comparative purposes for the wear values given in TABLE 1, the maximum stress imposed on the iron camshafts was 253 KSI. As seen in the figure, austempered ductile iron camshafts made according to the invention have only 0.001 in. to 0.002 in. of wear as compared to 0.009 in. for 8650 bar stock steel (the top end non-carburized steel currently being used for roller follower camshafts), and 0.013 in. for 5150 bar stock steel.
TABLE 1______________________________________CAMSHAFT LOBE WEAR COMPARISONSAFTER 100,000-MILE SIMULATION FORA MAXIMUM VALVE SPRING LOAD OF 298.9 LBS. MAXIMUM WEARCAMSHAFT MATERIAL (INCHES)______________________________________NON-AUSTEMPERED DUCTILE .010*IRONTITANIUM-NITRIDE NON- .002AUSTEMPERED DUCTILE IRON(ON COATED LOBES)AUSTEMPERED DUCTILE IRON .002(FURNACE TREATMENT OFENTIRE CAMSHAFT)SELECTIVE AUSTEMPERED .001DUCTILE IRON (TORCHTREATMENT OF CAMSHAFTLOBES)1050 BAR STOCK STEEL .004*(UNCARBURIZED)8650 BAR STOCK STEEL .0095150 BAR STOCK STEEL .0135150 VACUUM CAST STEEL .008______________________________________ *Tests terminated early due to rapidly wearing lobes
Camshafts 10 made according to the invention are cast in a conventional manner to form ductile iron. Although one embodiment of the invention includes premachining a camshaft which has not been heat-treated and then austempering the entire camshaft before its final machining, the preferred embodiment of the invention comprises selectively austempering only the camshaft lobes.
Selectively austempered camshafts 10 attain the required physical properties while reducing manufacturing time and cost. Because the high Hertzian stresses are imposed only on the lobes, only they need to be austempered. This method of austempering the camshafts 10 avoids interrupting the camshaft manufacturing line between the initial and final machining steps to austemper the parts as is required if the entire camshaft is furnace treated. For selectively austempered camshafts, all machining may be done at one time to the nonaustempered portions of the parts. The austempered camshaft lobes 14 may be ground as required.
According to this embodiment, as-cast ductile iron camshafts 10 are locally heated to the austenitizing temperature at the surface of the lobes by any suitable heating means such as flame torches, induction coils, plasma torches, electron beams, or lasers. The result is a layer of austempered ductile iron in the area where it is required. The remaining portions of the part remain in the form of as-cast ductile iron that can be easily machined. As seen in FIG. 5, the amount of lobe wear of selectively austempered ductile iron camshafts was actually slightly lower than the lobe wear of totally austempered ductile iron camshafts.
A selectively austempered ductile iron camshaft made according to the invention has been tested in an automobile engine. More particularly, the selectively austempered camshaft 10 was installed in a V-6 liter engine and subjected to a 500-hour durability test. The maximum Hertzian stress imposed on the camshaft was 230 KSI. In this test, the maximum amount of wear on the camshaft was 0.0004 inches.
The test results demonstrate the ability of austempered iron camshafts 10 to withstand high Hertzian stresses and to show little wear for the periods required to be used satisfactorily in automobiles or other engines.
While the invention has been described in connection with preferred embodiments thereof, it will be understood that we do not intend to limit the invention to those embodiments. To the contrary, we intend to cover all alternative modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
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An austempered ductile iron alloy with a mixed austenitic-bainitic structure is made by a method which enables the iron to withstand high cyclical stresses while having a high resistance to abrasion. Articles such as automobile roller-follower camshafts that are made from the iron alloy may have portions thereof selectively austempered to reduce the overall cost and time required to manufacture the article.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] (Provisional Application Serial No.) (Filing Date)
[0002] 60/121,730 Feb. 26, 1999
[0003] 60/146,564 Jul. 30, 1999
FEDERALLY SPONSORED RESEARCH
[0004] N/A
FIELD OF THE INVENTION
[0005] The invention relates to compounds and methods for use in biologic systems. More particularly, processes that transfer nucleic acids into cells are provided. Nucleic acids in the form of naked DNA or a nucleic acid combined with another compound are delivered to cells.
BACKGROUND
[0006] Biotechnology includes the delivery of a genetic information to a cell to express an exogenous nucleotide sequence, to inhibit, eliminate, augment, or alter expression of an endogenous nucleotide sequence, or to express a specific physiological characteristic not naturally associated with the cell. Polynucleotides may be coded to express a whole or partial protein, or may be anti-sense.
[0007] A basic challenge for biotechnology and thus its subpart, gene therapy, is to develop approaches for delivering genetic information to cells of a patient in a way that is efficient and safe. This problem of “drug delivery,” where the genetic material is a drug, is particularly challenging. If genetic material are appropriately delivered they can potentially enhance a patient's health and, in some instances, lead to a cure. Therefore, a primary focus of gene therapy is based on strategies for delivering genetic material in the form of nucleic acids. After delivery strategies are developed they may be sold commercially since they are then useful for developing drugs.
[0008] Delivery of a nucleic acid means to transfer a nucleic acid from a container outside a mammal to near or within the outer cell membrane of a cell in the mammal. The term transfection is used herein, in general, as a substitute for the term delivery, or, more specifically, the transfer of a nucleic acid from directly outside a cell membrane to within the cell membrane. The transferred (or transfected) nucleic acid may contain an expression cassette. If the nucleic acid is a primary RNA transcript that is processed into messenger RNA, a ribosome translates the messenger RNA to produce a protein within the cytoplasm. If the nucleic acid is a DNA, it enters the nucleus where it is transcribed into a messenger RNA that is transported into the cytoplasm where it is translated into a protein. Therefore if a nucleic acid expresses its cognate protein, then it must have entered a cell. A protein may subsequently be degraded into peptides, which may be presented to the immune system.
[0009] It was first observed that the in vivo injection of plasmid DNA into muscle enabled the expression of foreign genes in the muscle (Wolff, J A, Malone, R W, Williams, P, et al. Direct gene transfer into mouse muscle in vivo. Science 1990;247:1465-1468.). Since that report, several other studies have reported the ability for foreign gene expression following the direct injection of DNA into the parenchyma of other tissues. Naked DNA was expressed following its injection into cardiac muscle (Acsadi, G., Jiao, S., Jani, A., Duke, D., Williams, P., Chong, W., Wolff, J. A. Direct gene transfer and expression into rat heart in vivo. The New Biologist 3(1), 71-81, 1991.).
SUMMARY
[0010] In one preferred embodiment, a process is described for delivering a polynucleotide into a parenchymal cell of a mammal, comprising making a polynucleotide such as a nucleic acid. Then, inserting the polynucleotide into a mammalian vessel, such as a blood vessel and increasing the permeability of the vessel. Finally, delivering the polynucleotide to the parenchymal cell thereby altering endogenous properties of the cell. Increasing the permeability of the vessel consists of increasing pressure against vessel walls. Increasing the pressure consists of increasing a volume of fluid within the vessel. Increasing the volume consists of inserting the polynucleotide in a solution into the vessel wherein the solution contains a compound which complexes with the polynucleotide. A specific volume of the solution is inserted within a specific time period. Increased pressure is controlled by altering the specific volume of the solution in relation to the specific time period of insertion. The vessel may consist of a tail vein. The parenchymal cell is a cell selected from the group consisting of liver cells, spleen cells, heart cells, kidney cells and lung cells.
[0011] In another embodiment, a process is described for delivering a polynucleotide complexed with a compound into a parenchymal cell of a mammal, comprising making the polynucleotide-compound complex wherein the compound is selected from the group consisting of amphipathic compounds, polymers and non-viral vectors. Inserting the polynucleotide into a mammalian vessel and increasing the permeability of the vessel. Then, delivering the polynucleotide to the parenchymal cell thereby altering endogenous properties of the cell.
[0012] In yet another embodiment, a process is described for transfecting genetic material into a mammalian cell, comprising designing the genetic material for transfection. Inserting the genetic material into a mammalian blood vessel. Increasing permeability of the blood vessel and delivering the genetic material to the parenchymal cell for the purpose of altering endogenous properties of the cell.
DETAILED DESCRIPTION
[0013] We have found that an intravascular route of administration allows a polynucleotide to be delivered to a parenchymal cell in a more even distribution than direct parenchymal injections. The efficiency of polynucleotide delivery and expression is increased by increasing the permeability of the tissue's blood vessel. Permeability is increased by increasing the intravascular hydrostatic (physical) pressure, delivering the injection fluid rapidly (injecting the injection fluid rapidly), using a large injection volume, and increasing permeability of the vessel wall. Expression of a foreign DNA is obtained in large number of mammalian organs including; liver, spleen, lung, kidney and heart by injecting the naked polynucleotide. Increased expression occurs when polynucleotide is mixed with another compound.
[0014] In a first embodiment the compound consists of an amphipathic compound. Amphipathic compounds have both hydrophilic (water-soluble) and hydrophobic (water-insoluble) parts. The amphipathic compound can be cationic or incorporated into a liposome that is positively-charged (cationic) or non-cationic which means neutral, or negatively-charged (anionic). In another embodiment the compound consists of a polymer. In yet another embodiment the compound consists of a non-viral vector. In one embodiment, the compound does not aid the transfection process in vitro of cells in culture but does aid the delivery process in vivo in the whole organism. We also show that foreign gene expression can be achieved in hepatocytes following the rapid injection of naked plasmid DNA in a large volume of physiologic solutions.
[0015] The term intravascular refers to an intravascular route of administration that enables a polymer, oligonucleotide, or polynucleotide to be delivered to cells more evenly distributed than direct injections. Intravascular herein means within an internal tubular structure called a vessel that is connected to a tissue or organ within the body of an animal, including mammals. Within the cavity of the tubular structure, a bodily fluid flows to or from the body part. Examples of bodily fluid include blood, lymphatic fluid, or bile. Examples of vessels include arteries, arterioles, capillaries, venules, sinusoids, veins, lymphatics, and bile ducts. The intravascular route includes delivery through the blood vessels such as an artery or a vein.
[0016] Afferent blood vessels of organs are defined as vessels in which blood flows toward the organ or tissue under normal physiologic conditions. Efferent blood vessels are defined as vessels in which blood flows away from the organ or tissue under normal physiologic conditions. In the heart, afferent vessels are known as coronary arteries, while efferent vessels are referred to as coronary veins.
[0017] The term naked nucleic acids indicates that the nucleic acids are not associated with a transfection reagent or other delivery vehicle that is required for the nucleic acid to be delivered to a target cell. A transfection reagent is a compound or compounds used in the prior art that mediates nucleic acids entry into cells.
[0018] Parenchymal Cells
[0019] Parenchymal cells are the distinguishing cells of a gland or organ contained in and supported by the connective tissue framework. The parenchymal cells typically perform a function that is unique to the particular organ. The term “parenchymal” often excludes cells that are common to many organs and tissues such as fibroblasts and endothelial cells within blood vessels.
[0020] In a liver organ, the parenchymal cells include hepatocytes, Kupffer cells and the epithelial cells that line the biliary tract and bile ductules. The major constituent of the liver parenchyma are polyhedral hepatocytes (also known as hepatic cells) that presents at least one side to an hepatic sinusoid and opposed sides to a bile canaliculus. Liver cells that are not parenchymal cells include cells within the blood vessels such as the endothelial cells or fibroblast cells. In one preferred embodiment hepatocytes are targeted by injecting the polynucleotide within the tail vein of a rodent such as a mouse.
[0021] In striated muscle, the parenchymal cells include myoblasts, satellite cells, myotubules, and myofibers. In cardiac muscle, the parenchymal cells include the myocardium also known as cardiac muscle fibers or cardiac muscle cells and the cells of the impulse connecting system such as those that constitute the sinoatrial node, atrioventricular node, and atrioventricular bundle. In one preferred embodiment striated muscle such as skeletal muscle or cardiac muscle is targeted by injecting the polynucleotide into the blood vessel supplying the tissue. In skeletal muscle an artery is the delivery vessel; in cardiac muscle, an artery or vein is used.
[0022] Polymers
[0023] A polymer is a molecule built up by repetitive bonding together of smaller units called monomers. In this application the term polymer includes both oligomers which have two to about 80 monomers and polymers having more than 80 monomers. The polymer can be linear, branched network, star, comb, or ladder types of polymer. The polymer can be a homopolymer in which a single monomer is used or can be copolymer in which two or more monomers are used. Types of copolymers include alternating, random, block and graft.
[0024] One of our several methods of nucleic acid delivery to cells is the use of nucleic acid-polycations complexes. It was shown that cationic proteins like histones and protamines or synthetic polymers like polylysine, polyarginine, polyornithine, DEAE dextran, polybrene, and polyethylenimine are effective intracellular delivery agents while small polycations like spermine are ineffective.
[0025] A polycation is a polymer containing a net positive charge, for example poly-L-lysine hydrobromide. The polycation can contain monomer units that are charge positive, charge neutral, or charge negative, however, the net charge of the polymer must be positive. A polycation also can mean a non-polymeric molecule that contains two or more positive charges. A polyanion is a polymer containing a net negative charge, for example polyglutamic acid. The polyanion can contain monomer units that are charge negative, charge neutral, or charge positive, however, the net charge on the polymer must be negative. A polyanion can also mean a non-polymeric molecule that contains two or more negative charges. The term polyion includes polycation, polyanion, zwitterionic polymers, and neutral polymers. The term zwitterionic refers to the product (salt) of the reaction between an acidic group and a basic group that are part of the same molecule. Salts are ionic compounds that dissociate into cations and anions when dissolved in solution. Salts increase the ionic strength of a solution, and consequently decrease interactions between nucleic acids with other cations.
[0026] In one embodiment, polycations are mixed with polynucleotides for intravascular delivery to a cell. Polycations provide the advantage of allowing attachment of DNA to the target cell surface. The polymer forms a cross-bridge between the polyanionic nucleic acids and the polyanionic surfaces of the cells. As a result the main mechanism of DNA translocation to the intracellular space might be non-specific adsorptive endocytosis which may be more effective then liquid endocytosis or receptor-mediated endocytosis. Furthermore, polycations are a very convenient linker for attaching specific receptors to DNA and as result, DNA-polycation complexes can be targeted to specific cell types.
[0027] Additionally, polycations protect DNA in complexes against nuclease degradation. This is important for both extra- and intracellular preservation of DNA. The endocytic step in the intracellular uptake of DNA-polycation complexes is suggested by results in which DNA expression is only obtained by incorporating a mild hypertonic lysis step (either glycerol or DMSO). Gene expression is also enabled or increased by preventing endosome acidification with NH 4 CI or chloroquine. Polyethylenimine which facilitates gene expression without additional treatments probably disrupts endosomal function itself. Disruption of endosomal function has also been accomplished by linking the polycation to endosomal-disruptive agents such as fusion peptides or adenoviruses.
[0028] Polycations also cause DNA condensation. The volume which one DNA molecule occupies in complex with polycations is drastically lower than the volume of a free DNA molecule. The size of DNA/polymer complex may be important for gene delivery in vivo. In terms of intravenous injection, DNA needs to cross the endothelial barrier and reach the parenchymal cells of interest.
[0029] The average diameter of liver fenestrae (holes in the endothelial barrier) is about 100 nm, increases in pressure and/or permeability can increase the size of the fenestrae. The fenestrae size in other organs is usually less. The size of the DNA complexes is also important for the cellular uptake process. DNA complexes should be smaller than 200 nm in at least one dimension. After binding to the target cells the DNA- polycation complex is expected to be taken up by endocytosis.
[0030] Polymers may incorporate compounds that increase their utility. These groups can be incorporated into monomers prior to polymer formation or attached to the polymer after its formation. The gene transfer enhancing signal (Signal) is defined in this specification as a molecule that modifies the nucleic acid complex and can direct it to a cell location (such as tissue cells) or location in a cell (such as the nucleus) either in culture or in a whole organism. By modifying the cellular or tissue location of the foreign gene, the expression of the foreign gene can be enhanced.
[0031] The gene transfer enhancing signal can be a protein, peptide, lipid, steroid, sugar, carbohydrate, nucleic acid or synthetic compound. The gene transfer enhancing signals enhance cellular binding to receptors, cytoplasmic transport to the nucleus and nuclear entry or release from endosomes or other intracellular vesicles.
[0032] Nuclear localizing signals enhance the targeting of the gene into proximity of the nucleus and/or its entry into the nucleus. Such nuclear transport signals can be a protein or a peptide such as the SV40 large T ag NLS or the nucleoplasmin NLS. These nuclear localizing signals interact with a variety of nuclear transport factors such as the NLS receptor (karyopherin alpha) which then interacts with karyopherin beta. The nuclear transport proteins themselves could also function as NLS's since they are targeted to the nuclear pore and nucleus.
[0033] Signals that enhance release from intracellular compartments (releasing signals) can cause DNA release from intracellular compartments such as endosomes (early and late), lysosomes, phagosomes, vesicle, endoplasmic reticulum, golgi apparatus, trans golgi network (TGN), and sarcoplasmic reticulum. Release includes movement out of an intracellular compartment into cytoplasm or into an organelle such as the nucleus. Releasing signals include chemicals such as chloroquine, bafilomycin or Brefeldin A1 and the ER-retaining signal (KDEL sequence), viral components such as influenza virus hemagglutinin subunit HA-2 peptides and other types of amphipathic peptides.
[0034] Cellular receptor signals are any signal that enhances the association of the gene with a cell. This can be accomplished by either increasing the binding of the gene to the cell surface and/or its association with an intracellular compartment, for example: ligands that enhance endocytosis by enhancing binding the cell surface. This includes agents that target to the asialoglycoprotein receptor by using asialoglycoproteins or galactose residues. Other proteins such as insulin, EGF, or transferrin can be used for targeting. Peptides that include the RGD sequence can be used to target many cells. Chemical groups that react with sulfhydryl or disulfide groups on cells can also be used to target many types of cells. Folate and other vitamins can also be used for targeting. Other targeting groups include molecules that interact with membranes such as lipids fatty acids, cholesterol, dansyl compounds, and amphotericin derivatives. In addition viral proteins could be used to bind cells.
[0035] Polynucleotides
[0036] The term nucleic acid is a term of art that refers to a string of at least two base-sugar-phosphate combinations. (A polynucleotide is distinguished from an oligonucleotide by containing more than 120 monomeric units.) Nucleotides are the monomeric units of nucleic acid polymers. The term includes deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) in the form of an oligonucleotide messenger RNA, anti-sense, plasmid DNA, parts of a plasmid DNA or genetic material derived from a virus. Anti-sense is a polynucleotide that interferes with the function of DNA and/or RNA. The term nucleic acids- refers to a string of at least two base-sugar-phosphate combinations. Natural nucleic acids have a phosphate backbone, artificial nucleic acids may contain other types of backbones, but contain the same bases. Nucleotides are the monomeric units of nucleic acid polymers. The term includes deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). RNA may be in the form of an tRNA (transfer RNA), snRNA (small nuclear RNA), rRNA (ribosomal RNA), mRNA (messenger RNA), anti-sense RNA, and ribozymes. DNA may be in form plasmid DNA, viral DNA, linear DNA, or chromosomal DNA or derivatives of these groups. In addition these forms of DNA and RNA may be single, double, triple, or quadruple stranded. The term also includes PNAs (peptide nucleic acids), phosphorothioates, and other variants of the phosphate backbone of native nucleic acids.
[0037] A polynucleotide can be delivered to a cell to express an exogenous nucleotide sequence, to inhibit, eliminate, augment, or alter expression of an endogenous nucleotide sequence, or to express a specific physiological characteristic not naturally associated with the cell. Polynucleotides may be coded to express a whole or partial protein, or may be anti-sense.
[0038] A delivered polynucleotide can stay within the cytoplasm or nucleus apart from the endogenous genetic material. Alternatively, the polymer could recombine (become a part of) the endogenous genetic material. For example, DNA can insert into chromosomal DNA by either homologous or non-homologous recombination.
[0039] Vectors are polynucleic molecules originating from a virus, a plasmid, or the cell of a higher organism into which another nucleic fragment of appropriate size can be integrated without loss of the vectors capacity for self- replication; vectors typically introduce foreign DNA into host cells, where it can be reproduced. Examples are plasmids, cosmids, and yeast artificial chromosomes; vectors are often recombinant molecules containing DNA sequences from several sources. A vector includes a viral vector: for example, adenovirus; DNA; adenoassociated viral vectors (AAV) which are derived from adenoassociated viruses and are smaller than adenoviruses; and retrovirus (any virus in the family Retroviridae that has RNA as its nucleic acid and uses the enzyme reverse transcriptase to copy its genome into the DNA of the host cell's chromosome; examples include VSV G and retroviruses that contain components of lentivirus including HIV type viruses).
[0040] A non-viral vector is defined as a vector that is not assembled within an eukaryotic cell.
[0041] Permeability
[0042] In another preferred embodiment, the permeability of the vessel is increased. Efficiency of polynucleotide delivery and expression was increased by increasing the permeability of a blood vessel within the target tissue. Permeability is defined here as the propensity for macromolecules such as polynucleotides to move through vessel walls and enter the extravascular space. One measure of permeability is the rate at which macromolecules move through the vessel wall and out of the vessel. Another measure of permeability is the lack of force that resists the movement of polynucleotides being delivered to leave the intravascular space.
[0043] To obstruct, in this specification, is to block or inhibit inflow or outflow of blood in a vessel. Rapid injection may be combined with obstructing the outflow to increase permeability. For example, an afferent vessel supplying an organ is rapidly injected and the efferent vessel draining the tissue is ligated transiently. The efferent vessel (also called the venous outflow or tract) draining outflow from the tissue is also partially or totally clamped for a period of time sufficient to allow delivery of a polynucleotide. In the reverse, an efferent is injected and an afferent vessel is occluded.
[0044] In another preferred embodiment, the intravascular pressure of a blood vessel is increased by increasing the osmotic pressure within the blood vessel. Typically, hypertonic solutions containing salts such as NaCl, sugars or polyols such as mannitol are used. Hypertonic means that the osmolarity of the injection solution is greater than physiologic osmolarity. Isotonic means that the osmolarity of the injection solution is the same as the physiological osmolarity (the tonicity or osmotic pressure of the solution is similar to that of blood). Hypertonic solutions have increased tonicity and osmotic pressure similar to the osmotic pressure of blood and cause cells to shrink.
[0045] In another preferred embodiment, the permeability of the blood vessel can also be increased by a biologically-active molecule. A biologically-active molecule is a protein or a simple chemical such as papaverine or histamine that increases the permeability of the vessel by causing a change in function, activity, or shape of cells within the vessel wall such as the endothelial or smooth muscle cells. Typically, biologically-active molecules interact with a specific receptor or enzyme or protein within the vascular cell to change the vessel's permeability. Biologically-active molecules include vascular permeability factor (VPF) which is also known as vascular endothelial growth factor (VEGF). Another type of biologically-active molecule can also increase permeability by changing the extracellular connective material. For example, an enzyme could digest the extracellular material and increase the number and size of the holes of the connective material.
[0046] In another embodiment a non-viral vector along with a polynucleotide is intravascularly injected in a large injection volume. The injection volume is dependent on the size of the animal to be injected and can be from 1.0 to 3.0 ml or greater for small animals (i.e. tail vein injections into mice). The injection volume for rats can be from 6 to 35 ml or greater. The injection volume for primates can be 70 to 200 ml or greater. The injection volumes in terms of ml/body weight can be 0.03 ml/g to 0.1 ml/g or greater.
[0047] The injection volume can also be related to the target tissue. For example, delivery of a non-viral vector with a polynucleotide to a limb can be aided by injecting a volume greater than 5 ml per rat limb or greater than 70 ml for a primate. The injection volumes in terms of ml/limb muscle are usually within the range of 0.6 to 1.8 ml/g of muscle but can be greater. In another example, delivery of a polynucleotide to liver in mice can be aided by injecting the non-viral vector—polynucleotide in an injection volume from 0.6 to 1.8 ml/g of liver or greater. In another preferred embodiment, delivering a polynucleotide—non-viral vector to a limb of a primate (rhesus monkey), the complex can be in an injection volume from 0.6 to 1.8 ml/g of limb muscle or anywhere within this range.
[0048] In another embodiment the injection fluid is injected into a vessel rapidly. The speed of the injection is partially dependent on the volume to be injected, the size of the vessel to be injected into, and the size of the animal. In one embodiment the total injection volume (1-3 mls) can be injected from 15 to 5 seconds into the vascular system of mice. In another embodiment the total injection volume (6-35 mls) can be injected into the vascular system of rats from 20 to 7 seconds. In another embodiment the total injection volume (80-200 mls) can be injected into the vascular system of monkeys from 120 seconds or less.
[0049] In another embodiment a large injection volume is used and the rate of injection is varied. Injection rates of less than 0.012 ml per gram (animal weight) per second are used in this embodiment. In another embodiment injection rates of less than ml per gram (target tissue weight) per second are used for gene delivery to target organs. In another embodiment injection rates of less than 0.06 ml per gram (target tissue weight) per second are used for gene delivery into limb muscle and other muscles of primates.
[0050] Reporter Molecules
[0051] There are three types of reporter (marker) gene products that are expressed from reporter genes. The reporter gene/protein systems include:
[0052] a) Intracellular gene products such as luciferase, β-galactosidase, or chloramphenicol acetyl transferase. Typically, they are enzymes whose enzymatic activity can be easily measured.
[0053] b) Intracellular gene products such as β-galactosidase or green fluorescent protein which identify cells expressing the reporter gene. On the basis of the intensity of cellular staining, these reporter gene products also yield qualitative information concerning the amount of foreign protein produced per cell.
[0054] c) Secreted gene products such as growth hormone, factor IX, or alpha1-antitrypsin are useful for determining the amount of a secreted protein that a gene transfer procedure can produce. The reporter gene product can be assayed in a small amount of blood.
[0055] We have disclosed gene expression achieved from reporter genes in parenchymal cells. The terms “delivery,” “delivering genetic information,” “therapeutic” and “therapeutic results” are defined in this application as representing levels of genetic products, including reporter (marker) gene products, which indicate a reasonable expectation of genetic expression using similar compounds (nucleic acids), at levels considered sufficient by a person having ordinary skill in the art of delivery and gene therapy. For example: Hemophilia A and B are caused by deficiencies of the X-linked clotting factors VIII and IX, respectively. Their clinical course is greatly influenced by the percentage of normal serum levels of factor VIII or IX:<2%, severe; 2-5%, moderate; and 5-30% mild. This indicates that in severe patients only 2% of the normal level can be considered therapeutic. Levels greater than 6% prevent spontaneous bleeds but not those secondary to surgery or injury. A person having ordinary skill in the art of gene therapy would reasonably anticipate therapeutic levels of expression of a gene specific for a disease based upon sufficient levels of marker gene results. In the Hemophilia example, if marker genes were expressed to yield a protein at a level comparable in volume to 2% of the normal level of factor VIII, it can be reasonably expected that the gene coding for factor VIII would also be expressed at similar levels.
EXAMPLES
[0056] Enhanced Delivery of Naked DNA
[0057] Enhancement of in vivo Gene Expression by M-methyl-L-arginine (L-NMMA) Following Intravascular Delivery of Naked DNA:
[0058] Intravascular delivery of pCILuc via the iliac artery of rat following a short pre-treatment with L-NMMA delivery enhancer. A 4 cm long abdominal midline excision was performed in 150-200 g, adult Sprague-Dawley rats anesthesized with 80 mg/mg ketamine and 40 mg/kg xylazine. Microvessel clips were placed on external iliac, caudal epigastric, internal iliac and deferent duct arteries and veins to block both outflow and inflow of the blood to the leg. 3 ml of normal saline with 0.66 mM L-NMMA were injected into the external iliac artery. After 2 min 27 g butterfly needle was inserted into the external iliac artery and 10 ml of DNA solution (50 ug/ml pCILuc) in normal saline was injected within 8-9 sec. Luciferase assays was performed 2 days after injection on limb muscle samples (quadriceps femoris).
[0059] Organ Treatment Total Luciferase (Nanograms)
[0060] Muscle (quadriceps)+papaverine 9,999
[0061] Muscle (quadriceps)+0.66 mM L-NMMA 15,398
[0062] Muscle (quadriceps)+papaverine, +0.66 mM L-NMMA 24,829
[0063] 2) Enhancement of in vivo Gene Expression by aurintricarboxylic Acid (ATA) Delivery Enhancer Following Intravascular Delivery of Naked DNA.
[0064] Intravascular delivery of pCILuc in the absence or presence of aurintricarboxylic acid via tail vein injection into mice. 10 micrograms of pCILuc was diluted to 2.5 ml with Ringers solution and aurintricarboxylic acid was added to a final concentration of 0.11 mg/ml. The DNA solution was injected into the tail vein of 25 g ICR mice with an injection time of ˜7 seconds. Mice were sacrificed 24 hours after injection and various organs were assayed for luciferase expression.
[0065] Organ Treatment Total Relative Light Units per Organ
[0066] Liver none 55,300,000,000
[0067] Liver+ATA 109,000,000,000
[0068] Spleen none 63,200,000
[0069] Spleen+ATA 220,000,000
[0070] Lung none 100,000,000
[0071] Lung+ATA 128,000,000
[0072] Heart none 36,700,000
[0073] Heart+ATA 32,500,000
[0074] Kidney none 15,800,000
[0075] Kidney+ATA 82,400,000
[0076] DNA/Polymer Delivery
[0077] Rapid injection of pDNA/cationic polymer complexes (containing 10 μg of pCILuc; a luciferase expression vector utilizing the human CMV promoter) in 2.5 ml of Ringers solution (147 mM NaCl, 4 mM KCl, 1.13 mM CaCl2) into the tail vein of ICR mice facilitated expression levels higher than comparable injections using naked plasmid DNA (pCILuc). Maximal luciferase expression using the tail vein approach was achieved when the DNA solution was injected within 7 seconds. Luciferase expression was also critically dependent on the total injection volume and high level gene expression in mice was obtained following tail vein injection of polynucleotide/polymer complexes of 1, 1.5, 2, 2.5, and 3 ml total volume. There is a positive correlation between injection volume and gene expression for total injection volumes over 1 ml. For the highest expression efficiencies an injection delivery rate of greater than 0.003 ml per gram (animal weight) per second is likely required. Injection rates of 0.004, 0.006, 0.009, 0.012 ml per gram (animal weight) per second yield successively greater gene expression levels.
[0078] The graph above illustrates high level luciferase expression in liver following tail vein injections of naked plasmid DNA and plasmid DNA complexed with labile disulfide containing polycations L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer (M66) and 5,5′-Dithiobis(2-nitrobenzoic acid)—Pentaethylenehexamine Copolymer (M72). The labile polycations were complexed with DNA at a 3:1 wt:wt ratio resulting in a positively charged complex. Complexes were injected into 25 gram ICR mice in a total volume of 2.5 ml of ringers solution.
[0079] The graph above indicates high level luciferase expression in spleen, lung, heart and kidney following tail vein injections of naked plasmid DNA and plasmid DNA complexed with labile disulfide containing polycations M66 and M72. The labile polycations were complexed with DNA at a 3:1 wt:wt ratio resulting in a positively charged complex. Complexes were injected into 25 gram ICR mice in a total volume of 2.5 ml of ringers solution.
[0080] Luciferase Expression in a Variety of Tissues Following a Single Tail Vein Injection of pCILuc/66 Complexes:
[0081] DNA and polymer 66 were mixed at a 1:1.7 wt:wt ratio in water and diluted to 2.5 ml with Ringers solution as described. Complexes were injected into tail vein of 25 g ICR mice within 7 seconds. Mice were sacrificed 24 hours after injection and various organs were assayed for luciferase expression.
[0082] Organ Total Relative Light Units
[0083] Prostate 637,000
[0084] Skin (abdominal wall) 194,000
[0085] Testis 589,000
[0086] Skeletal Muscle (quadriceps) 35,000
[0087] fat (peritoneal cavity) 44,700
[0088] bladder 17,000
[0089] brain 247,000
[0090] pancreas 2,520,000
[0091] Directed intravascular injection of pCILuc/66 polymer complexes into dorsal vein of penis results in high level gene expression in the prostate and other localized tissues: Complexes were formed as described for example above and injected rapidly into the dorsal vein of the penis (within 7 seconds). For directed delivery to the prostate with increased hydrostatic pressure, clamps were applied to the inferior vena cava and the anastomotic veins just prior to the injection and removed just after the injection (within 5-10 seconds). Mice were sacrificed 24 hours after injection and various organs were assayed for luciferase expression.
[0092] Organ Total Relative Light Units per Organ
[0093] Prostate 129,982,450
[0094] Testis 4,229,000
[0095] fat (around bladder) 730,300
[0096] bladder 618,000
[0097] Intravascular Tail Vein Injection into Rat Results in High Level Gene Expression in a Variety of Organs:
[0098] 100 micrograms of pCILuc was diluted into 30 mls Ringers solution and injected into the tail vein of 480 gram Harlan Sprague Dawley rat. The entire volume was delivered within 15 seconds. 24 hours after injection various organs were harvested and assayed for luciferase expression.
[0099] Organ Total Relative Light Units per Organ
[0100] Liver 30,200,000,000
[0101] Spleen 14,800,000
[0102] Lung 23,600,000
[0103] Heart 5,540,000
[0104] Kidney 19,700,000
[0105] Prostate 3,490,000
[0106] Skeletal Muscle (quadriceps) 7,670,000
[0107] Cleavable Polymers
[0108] A prerequisite for gene expression is that once DNA/cationic polymer complexes have entered a cell the polynucleotide must be able to dissociate from the cationic polymer. This may occur within cytoplasmic vesicles (i.e. endosomes), in the cytoplasm, or the nucleus. We have developed bulk polymers prepared from disulfide bond containing co-monomers and cationic co-monomers to better facilitate this process. These polymers have been shown to condense polynucleotides, and to release the nucleotides after reduction of the disulfide bond. These polymers can be used to effectively complex with DNA and can also protect DNA from DNases during intravascular delivery to the liver and other organs. After internalization into the cells the polymers are reduced to monomers, effectively releasing the DNA, as a result of the stronger reducing conditions (glutathione) found in the cell. Negatively charged polymers can be fashioned in a similar manner, allowing the condensed nucleic acid particle (DNA+polycation) to be “recharged” with a cleavable anionic polymer resulting in a particle with a net negative charge that after reduction of disulfide bonds will release the polynucleic acid. The reduction potential of the disulfide bond in the reducible co-monomer can be adjusted by chemically altering the disulfide bonds environment. This will allow the construction of particles whose release characteristics can be tailored so that the polynucleic acid is released at the proper point in the delivery process.
[0109] Cleavable Cationic Polymers
[0110] Cationic cleavable polymers are designed such that the reducibility of disulfide bonds, the charge density of polymer, and the functionalization of the final polymer can all be controlled. The disulfide co-monomer can have reactive ends chosen from, but not limited to the following: the disulfide compounds contain reactive groups that can undergo acylation or alkylation reactions. Such reactive groups include isothiocyanate, isocyanate, acyl azide, N-hydroxysuccinimide esters, succinimide esters, sulfonyl chloride, aldehyde, epoxide, carbonate, imidoester, carboxylate, alkylphosphate, arylhalides (e.g. difluoro-dinitrobenzene) or succinic anhydride.
[0111] If functional group A (cationic co-monomer) is an amine then B (disulfide containing comonomer) can be (but not restricted to) an isothiocyanate, isocyanate, acyl azide, N-hydroxysuccinimide, sulfonyl chloride, aldehyde (including formaldehyde and glutaraldehyde), epoxide, carbonate, imidoester, carboxylate, or alkylphosphate, arylhalides (difluoro-dinitrobenzene) or succinic anhyride. In other terms when function A is an amine then function B can be acylating or alkylating agent.
[0112] If functional group A is a sulfhydryl then functional group B can be (but not restricted to) an iodoacetyl derivative, maleimide, vinyl sulfone, aziridine derivative, acryloyl derivative, fluorobenzene derivatives, or disulfide derivative (such as a pyridyl disulfide or 5-thio-2-nitrobenzoic acid{TNB} derivatives).
[0113] If functional group A is carboxylate then functional group B can be (but not restricted to) a diazoacetate or an amine, alcohol, or sulfhydryl in which carbonyldiimidazole or carbodiimide is used.
[0114] If functional group A is an hydroxyl then functional group B can be (but not restricted to) an epoxide, oxirane, or an carboxyl group in which carbonylduimidazole or carbodiimide or N, N′-disuccinimidyl carbonate, or N-hydroxysuccinimidyl chloroformate is used.
[0115] If functional group A is an aldehyde or ketone then function B can be (but not restricted to) an hydrazine, hydrazide derivative, a mine (to form a Schiff Base that may or may not be reduced by reducing agents such as NaCNBH 3 ).
[0116] The polymer is formed by simply mixing the cationic, and disulfide-containing co-monomers under appropriate conditions for reaction. The resulting polymer may be purified by dialysis or size-exclusion chromatography.
[0117] The reduction potential of the disulfide bond can be controlled in two ways. Either by altering the reduction potential of the disulfide bond in the disulfide-containing co-monomer, or by altering the chemical environment of the disulfide bond in the bulk polymer through choice the of cationic co-monomer.
[0118] The reduction potential of the disulfide bond in the co-monomer can be controlled by synthesizing new cross-linking reagents. Dimethyl 3,3′-dithiobispropionimidate (DTBP) is a commercially available disulfide containing crosslinker from Pierce Chemical Co. This disulfide bond is reduced by dithiothreitol (DTT), but is only slowly reduced, if at all by biological reducing agents such as glutathione. More readily reducible crosslinkers have been synthesized by Mirus. These crosslinking reagents are based on aromatic disulfides such as 5,5′-dithiobis(2-nitrobenzoic acid) and 2,2′-dithiosalicylic acid. The aromatic rings activate the disulfide bond towards reduction through delocalization of the transient negative charge on the sulfur atom during reduction. The nitro groups further activate the compound to reduction through electron withdrawal which also stabilizes the resulting negative charge.
[0119] Cleavable disulfide containing co-monomers:
[0120] DTBP
[0121] Activated Disulfide Crosslinkers
[0122] diimidate activated crosslinker
[0123] diimidate activated crosslinker with additional positive charge
[0124] di-NHS ester activated crosslinker with additional positive charge
[0125] di-NHS ester activated crosslinker with no additional positive charge
[0126] dithiosalicylic acid Dithionicotinic acid
[0127] Ellman's reagent
[0128] The reduction potential can also be altered by proper choice of cafionic co-monomer. For example when DTBP is polymerized along with diaminobutane the disulfide bond is reduced by DTT, but not glutathione. When ethylenediamine is polymerized with DTBP the disulfide bond is now reduced by glutathione. This is apparently due to the proximity of the disulfide bond to the amidine functionality in the bulk polymer.
[0129] The charge denisty of the bulk polymer can be controlled through choice of cationic monomer, or by incorporating positive charge into the disulfide co-monomer. For example spermine a molecule containing 4 amino groups spaced by 3-4-3 methylene groups could be used for the cationic monomer. Because of the spacing of the amino groups they would all bear positive charges in the bulk polymer with the exception of the end primary amino groups that would be derivitized during the polymerization. Another monomer that could be used is N,N′-bis(2-aminoethyl)-1,3-propediamine (AEPD) a molecule containing 4 amino groups spaced by 2-3-2 methylene groups. In this molecule the spacing of the amines would lead to less positive charge at physiological pH, however the molecule would exhibit pH sensitivity, that is bear different net positive charge, at different pH's. A molecule such as tetraethylenepentamine could also be used as the cationic monomer, this molecule consists of 5 amino groups each spaced by two methylene units. This molecule would give the bulk polymer pH sensitivity, due to the spacing of the amino groups as well as charge density, due to the number and spacing of the amino groups. The charge density can also be affected by incorporating positive charge into the disulfide containing monomer, or by using imidate groups as the reactive portions of the disulfide containing monomer as imidates are transformed into amidines upon reaction with amine which retain the positive charge.
[0130] The bulk polymer can be designed to allow further functionalization of the polymer by incorporating monomers with protected primary amino groups. These protected primary amines can then be deprotected and used to attach other functionalities such as nuclear localizing signals, endosome disrupting peptides, cell-specific ligands, fluorescent marker molecules, as a site of attachment for further crosslinking of the polymer to itself once it has been complexed with a polynucleic acid, or as a site of attachment for a second anionic layer when a cleavable polymer/polynucleic acid particle is being recharged to an anionic particle. An example of such a molecule is 3,3′-(N′,N″-tert-butoxycarbonyl)-N-(3′-trifluoroacetamidylpropane)-N-methyldipropylammonium bromide (see experimental), this molecule would be incorporated by removing the two BOC protecting groups, incorporating the deprotected monomer into the bulk polymer, followed by deprotection of the trifluoroacetamide protecting group.
[0131] Cleavable Anionic Polymers
[0132] Cleavable anionic polymers can be designed in much the same manner as the cationic polymers. Short, multi-valent oligopeptides of glutamic or aspartic acid can be synthesized with the carboxy terminus capped with ethylene diamine. This oligo can the be incorporated into a bulk polymer as a co-monomer with any of the amine reactive disulfide containing crosslinkers mentioned previously. A preferred crosslinker would make use of NHS esters as the reactive group to avoid retention of positive charge as occurs with imidates. The cleavable anionic polymers can be used to recharge positively charged particles of condensed polynucleic acids.
[0133] Examples of cleavable polymers:
[0134] Co-ethylenediamine/DTBP cleavable cationic polymer
[0135] Co-diaminobutane/DTBP cleavable cationic polymer
[0136] Co-glutamic acid/activated disulfide cleavable anionic polymer
[0137] The cleavable anionic polymers can have co-monomers incorporated to allow attachment of cell-specific ligands, endosome disrupting peptides, fluorescent marker molecules, as a site of attachment for further crosslinking of the polymer to itself once it has been complexed with a polynucleic acid, or as a site of attachment for to the initial cationic layer. For example the carboxyl groups on a portion of the anionic co-monomer could be coupled to an aminoalcohol such as 4-hydroxybutylamine. The resulting alcohol containing comonomer can be incorporated into the bulk polymer at any ratio. The alcohol functionalities can then be oxidized to aldehydes, which can be coupled to amine containing ligands etc. in the presence of sodium cyanoborohydride via reductive amination.
[0138] Synthesis of Activated Disulfide Containing Co-Monomers
[0139] Synthesis of 5,5′-dithiobis(2-nitrobenzoate)propionitrile: 5,5′-dithiobis(2-nitrobenzoic acid) [Ellman's reagent] (500 mg, 1.26 mmol) was dissolved in 4.0 ml dioxane. Dicylohexylcarbodiimide (540 mg, 2.6 mmol) and 3-hydroxypropionitrile (240 μL, 188 mg, 2.60 mmol) were added. The reaction mixture was stirred overnight at room temperature. The urea precipitate was removed by centrifugation. The dioxane was removed on rotary evaporator. The residue was washed with saturated bicarbonate, water, and brine; and dried over magnesium sulfate. Solvent removal yielded 696 mg yellow/orange foam. The residue was purified using normal phase HPLC (Alltech econosil, 250×22 nm), flow rate=9.0 ml/min, mobile phase=1% ethanol in chloroform, retention time=13 min. Removal of solvent afforded 233 mg (36.8%) product as a yellow oil. TLC (silica: 5% methanol in chloroform; rf=0.51). H 1 NMR ∂ 8.05 (d, 4 H), 7.75 (m, 4H), 4.55 (t, 4H), 2.85 (t, 4H).
[0140] Synthesis of 5,5′-dithiobis(2-nitrobenzoic acid)dimethyl propionimidate [DTNBP]: (113.5 mg, 0.226 mmol) was dissolved in 500 μL anhydrous chloroform along with anhydrous methanol (20.0 μL, 0.494 mmol). The flask was stoppered with a rubber septum, chilled to 0° C. on an ice bath, and HCl gas produced by mixing sulfuric acid and ammonium chloride was bubbled through the solution for a period of 10 minutes. The flask was then tightly sealed with parafilm and placed in a −20° C. freezer for a period of 48 hours. During this time a yellow oil formed. The oil was washed thoroughly with chloroform and dried under vacuum to yield 137 mg (95.8%) product as a yellow foam.
[0141] 3,3′-(N,N″-tert-butoxycarbonyl)-N-methyldipropylamine (1). 3,3′-Diamino-N-methyldipropylamine (0.800 ml, 0.721 g, 5.0 mmol) was dissolved in 5.0 ml 2.2 N sodium hydroxide (11 mmol). To the solution was added Boc anhydride (2.50 ml, 2.38 g, 10.9 mmol) with magnetic stirring. The reaction mixture was allowed to stir at room temperature overnight (approximately 18 hours). The reaction mixture was made basic by adding additional 2.2 N NaOH until all t-butyl carboxylic acid was in solution. The solution was then extracted into chloroform (2×20 ml). The combined chloroform extracts were washed 2×10 ml water and dried over magnesium sulfate. Solvent removal yielded 1.01 g (61.7%) product as a white solid: 1 H-NMR (CDCl 3 ) δ5.35 (bs, 2H), 3.17 (dt, 4H), 2.37 (t, 4H), 2.15 (s, 3H), 1.65 (tt, 4H), 1.45 (s, 18H).
[0142] 3,3′-(N′,N″-tert-butoxycarbonyl)-N-(3′-trifluoroacetamidylpropane)-N-methyldipropylammonium bromide (13). Compound 1 (100.6 mg, 0.291 mmol) and compound 4 (76.8 mg, 0.328 mmol) were dissolved in 0.150 ml dimethylformamide. The reaction mixture was incubated at 50° C. for 3 days. TLC (reverse phase; acetonitrile: 50 mM ammonium acetate pH 4.0; 3:1) showed 1 major and 2 minor spots none of which corresponded to starting material. Recrystalization attempts were unsuccessful so product was precipitated from ethanol with ether yielding 165.5 mg (98.2%) product and minor impurities as a clear oil: 1 H-NMR (CDCl 3 ) δ9.12 (bs,1H), 5.65 (bs, 2H), 3.50 (m, 8H), 3.20 (m, 4H), 3.15 (s, 3H), 2.20 (m, 2H), 2.00 (m, 4H), 1.45 (s, 18H).
[0143] Intravascular Injections of DNA/Polymer Complexes
[0144] Synthesis of N,N′-Bis(t-BOC)-L-cystine:
[0145] To a solution of L-cystine (1 μm,4.2 mmol, Aldrich Chemical Company) in acetone (10 ml) and water (10 ml) was added 2-(tert-butoxycarbonyloxyimino)-2-phenylacetonitrile (2.5 μm, 10 mmol, Aldrich Chemical Company) and triethylamine (1.4 ml, 10 mmol, Aldrich Chemical Company). The reaction was allowed to stir overnight at room temperature. The water and acetone was then by rotary evaporation resulting in a yellow solid. The diBOC compound was then isolated by flash chromatography on silica gel eluting with ethyl acetate 0.1% acetic acid.
[0146] Synthesis of L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer (M66):
[0147] To a solution of N,N′-Bis(t-BOC)-L-cystine (85 mg, 0.15 mmol) in ethyl acetate (20 ml) was added N,N′-dicyclohexylcarbodiimide (108 mg, 0.5 mmol) and N-hyroxysuccinimide (60 mg, 0.5 mmol). After 2 hr, the solution was filtered through a cotton plug and 1,4-bis(3-aminopropyl)piperazine (54 μL, 0.25 mmol) was added. The reaction was allowed to stir at room temperature for 16 h. The ethyl acetate was then removed by rotary evaporation and the resulting solid was dissolved in trifluoroacetic acid (9.5 ml), water (0.5 ml) and triisopropylsilane (0.5 ml). After 2 h, the trifluoroacetic acid was removed by rotary evaporation and the aqueous solution was dialyzed in a 15,000 MW cutoff tubing against water (2×2 l) for 24 h. The solution was then removed from dialysis tubing, filtered through 5 μM nylon syringe filter and then dried by lyophilization to yield 30 mg of polymer.
[0148] Injection of plasmid DNA (pCILuc)/L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer (M66) complexes into the iliac artery of rats.
[0149] Complex formation—500 ug pDNA (500 ul) was mixed with M66 copolymer at a 1:3 wt:wt ratio in 500 ul saline. Complexes were then diluted in Ringers solution to total volume of 10 mls.
[0150] Injections—total volume of 10 mls was injected into the iliac artery of Sprague-Dawley rats (Harlan, Indianapolis, Ind.) in approximately 10 seconds.
[0151] Expression—Animals were sacrificed after 1 week and individual muscle groups were removed and assayed for luciferase expression.
[0152] Rat hind limb muscle groups.
[0153] 1) upper leg posterior—6.46×10 8 total Relative Light Units (32 ng luciferase)
[0154] 2) upper leg anterior—3.58×10 9 total Relative Light Units (183 ng luciferase)
[0155] 3) upper leg middle—2.63×10 9 total Relative Light Units (134 ng luciferase)
[0156] 4) lower leg anterior—3.19×10 9 total Relative Light Units (163 ng luciferase)
[0157] 5) lower leg anterior—1.97×10 9 total Relative Light Units (101 ng luciferase)
[0158] These results indicate that high level gene expression in all muscle groups of the leg was facilitated by intravascular delivery of pCILuc/M66 complexes into rat iliac artery.
[0159] Synthesis of 5,5′-Dithiobis[succinimidyl(2-nitrobenzoate):
[0160] 5,5′-dithiobis(2-nitrobenzoic acid) (50.0 mg, 0.126 mmol, Aldrich Chemical Company) and N-hyroxysuccinimide (29.0 mg, 0.252 mmol, Aldrich Chemical Company) were taken up in 1.0 ml dichloromethane. Dicylohexylcarbodiimide (52.0 mg, 0.252 mmol) was added and the reaction mixture was stirred overnight at room temperature. After 16 hr, the reaction mixture was partitioned in EtOAc/H 2 O. The organic layer was washed 2×H 2 O, 1×brine, dried (MgSO 4 ) and concentrated under reduced pressure. The residue was taken up in CH 2 Cl 2 , filtered, and purified by flash column chromatography on silica gel (130×30 mm, EtOAc:CH 2 Cl 2 1:9 eluent) to afford 42 mg (56%) 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] as a white solid. H 1 NMR (DMSO) ∂ 7.81−7.77 (d, 2H), 7.57−7.26 (m, 4H), 3.69 (s, 8 H).
[0161] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—Pentaethylenehexamine Copolymer (M72):
[0162] Pentaethylenehexamine (4.2 μL, 0.017 mmol, Aldrich Chemical Company) was taken up in 1.0 ml dichloromethane and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (12 μL, 0.068 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 hr. The solution was then removed from dialysis tubing and dried by lyophilization to yield 5.9 mg (58%) of 5,5′-dithiobis(2-nitrobenzoic acid)—pentaethylenehexamine Copolymer.
[0163] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine Copolymer (#M57):
[0164] Tetraethylenepentamine (3.2 μL, 0.017 mmol, Aldrich Chemical Company) was taken up in 1.0 ml dichloromethane and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl (2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (15 μL, 0.085 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 h. The solution was then removed from dialysis tubing and dried by lyophilization to yield 5.8 mg (62%) of 5,5′-dithiobis(2-nitrobenzoic acid)—tetraethylenepentamine copolymer.
[0165] Mouse Tail Vein Injections of pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine Copolymer Complexes:
[0166] Complexes were prepared as follows:
[0167] Complex I: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 2.5 ml Ringers was added.
[0168] Complex II: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine Copolymer (336 μg) was added followed by 2.5 ml Ringers.
[0169] High pressure (2.5 ml) tail vein injections of the complex were performed as previously described (Zhang, G., Budker, V., Wolff, J. “High Levels of Foreign Gene Expression in Hepatocytes from Tail Vein Injections of Naked Plasmid DNA”, Human Gene Therapy, July, 1999). Results reported are for liver expression, and are the average of two mice. Luciferase expression was determined as previously reported (Wolff, J. A., Malone, R. W., Williams, P., Chong, W., Acsadi, G., Jani, A., and Felgner, P. L., 1990 “Direct gene transfer into mouse muscle in vivo,” Science 247, 1465-8.) A Lumat LB 9507 (EG&G Berthold, Bad-Wildbad, Germany) luminometer was used.
[0170] Results: High pressure injections
[0171] Complex I: 25,200,000 Relative Light Units
[0172] Complex II: 21,000,000 Relative Light Units
[0173] Results indicate that pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—tetraethylenepentamine copolymer complexes are nearly equivalent to pCI Luc DNA itself in high pressure injections. This indicates that the pDNA is being released from the complex and is accessible for transcription.
[0174] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine—Tris(2-aminoethyl)amine Copolymer (#M58):
[0175] Tetraethylenepentamine (2.3 μL, 0.012 mmol, Aldrich Chemical Company) and tris(2-aminoethyl)amine (0.51 μL, 0.0034 mmol, Aldrich Chemical Company) were taken up in 0.5 ml methanol and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added. Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl (2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (15 μL, 0.085 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 h. The solution was then removed from dialysis tubing and dried by lyophilization to yield 6.9 mg (77%) of 5,5′-dithiobis(2-nitrobenzoic acid)—tetraethylenepentamine—tris(2-aminoethyl)amine copolymer.
[0176] Mouse Tail Vein Injections of pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine-Tris(2-aminoethyl)amine Copolymer Complexes:
[0177] Complexes were prepared as follows:
[0178] Complex I: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 2.5 ml Ringers was added.
[0179] Complex II: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 5,5′-Dithiobis(2-nitrobenzoic acid)—Tetraethylenepentamine-Tris(2-aminoethyl)amine Copolymer (324 μg) was added followed by 2.5 ml Ringers.
[0180] High pressure (2.5 ml) tail vein injections of the complex were performed as previously described. Results reported are for liver expression, and are the average of two mice. Luciferase expression was determined a previously shown.
[0181] Results: High pressure injections
[0182] Complex I: 25,200,000 Relative Light Units
[0183] Complex II: 37,200,000 Relative Light Units
[0184] Results indicate that pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—tetraethylenepentamine-Tris(2-aminoethyl)amine Copolymer Complexes are more effective than pCI Luc DNA in high pressure injections. This indicates that the pDNA is being released from the complex and is accessible for transcription.
[0185] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine Copolymer (#M59):
[0186] N,N′-Bis(2-aminoethyl)-1,3-propanediamine (2.8 μL, 0.017 mmol, Aldrich Chemical Company) was taken up in 1.0 ml dichloromethane and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added. Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (12 μL, 0.068 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 hr. The solution was then removed from dialysis tubing and dried by lyophilization to yield 5.9 mg (66%) of 5,5′-dithiobis(2-nitrobenzoic acid)-N,N′-bis(2-aminoethyl)-1,3-propanediamine Copolymer.
[0187] Mouse Tail Vein Injections of pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine Copolymer Complexes:
[0188] Complexes were prepared as follows:
[0189] Complex I: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 2.5 ml Ringers was added.
[0190] Complex II: pDNA (pCI Luc, 200 μg) was added to 300μL DMSO then 5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine Copolymer (474 μg) was added followed by 2.5 ml Ringers.
[0191] High pressure tail vein injections of 2.5 ml of the complex were performed as previously described. Results reported are for liver expression, and are the average of two mice. Luciferase expression was determined as previously shown.
[0192] Results: High pressure injections
[0193] Complex I: 25,200,000 Relative Light Units
[0194] Complex II: 341,000 Relative Light Units
[0195] Results indicate that pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—tetraethylenepentamine Copolymer Complexes are less effective than pCI Luc DNA in high pressure injections. Although the complex was less effective, the luciferase expression indicates that the pDNA is being released from the complex and is accessible for transcription.
[0196] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine—Tris(2-aminoethyl)amine Copolymer (#M60):
[0197] N,N′-Bis(2-aminoethyl)-1,3-propanediamine (2.0 μL, 0.012 mmol, Aldrich Chemical Company) and tris(2-aminoethyl)amine (0.51 μL, 0.0034 mmol, Aldrich Chemical Company) were taken up in 0.5 ml methanol and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added. Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (12 μL, 0.068 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 hr. The solution was then removed from dialysis tubing and dried by lyophilization to yield 6.0 mg (70%) of 5,5′-dithiobis(2-nitrobenzoic acid)—N,N′-bis(2-aminoethyl)-1,3-propanediamine—tris(2-aminoethyl)amine copolymer.
[0198] Mouse Tail Vein Injections of pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine—Tris(2-aminoethyl)amine Copolymer Complexes:
[0199] Complexes were prepared as follows:
[0200] Complex I: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 2.5 ml Ringers was added.
[0201] Complex II: pDNA (pCI Luc, 200 μg) was added to 300 μL DMSO then 5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine—Tris(2-aminoethyl)amine Copolymer (474 μg) was added followed by 2.5 ml Ringers.
[0202] High pressure tail vein injections of 2.5 ml of the complex were preformed as previously described. Results reported are for liver expression, and are the average of two mice. Luciferase expression was determined as previously shown.
[0203] Results: High pressure injections
[0204] Complex I: 25,200,000 Relative Light Units
[0205] Complex II: 1,440,000 Relative Light Units
[0206] Results indicate that pDNA (pCI Luc)/5,5′-Dithiobis(2-nitrobenzoic acid)—N,N′-Bis(2-aminoethyl)-1,3-propanediamine—Tris(2-aminoethyl)amine Copolymer Complexes are less effective than pCI Luc DNA in high pressure injections. Although the complex was less effective, the luciferase expression indicates that the pDNA is being released from the complex and is accessible for transcription.
[0207] Synthesis of guanidino-L-cystine 1.4—bis(3—aminopropyl)piperazine copolymer (#M67):
[0208] To a solution of cystine (1 gm, 4.2 mmol) in ammonium hydroxide (10 ml) in a screw-capped vial was added O-methylisourea hydrogen sulfate (1.8 gm, 10 mmol). The vial was sealed and heated to 60° C. for 16 h. The solution was then cooled and the ammonium hydroxide was removed by rotary evaporation. The solid was then dissolved in water (20 ml), filtered through a cotton plug. The product was then isolated by ion exchange chromatography using Bio-Rex 70 resin and eluting with hydrochloric acid (100 mM).
[0209] Synthesis of guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer:
[0210] To a solution of guanidino-L-cystine (64 mg, 0.2 mmol) in water (10 ml) was slowly added N,N′-dicyclohexylcarbodiimide (82 mg, 0.4 mmol) and N-hyroxysuccinimide (46 mg, 0.4 mmol) in dioxane (5 ml). After 16 hr, the solution was filtered through a cotton plug and 1,4-bis(3-aminopropyl)piperazine (40 μL, 0.2 mmol) was added. The reaction was allowed to stir at room temperature for 16 h and then the aqueous solution was dialyzed in a 15,000 MW cutoff tubing against water (2×2 l) for 24 h. The solution was then removed from dialysis tubing, filtered through 5 μM nylon syringe filter and then dried by lyophilization to yield 5 mg of polymer.
[0211] Particle size of pDNA-L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer and DNA-guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer complexes:
[0212] To a solution of pDNA (10 μg/ml) in 0.5 ml 25 mM HEPES buffer pH 7.5 was added 10 μg/ml L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer or guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer. The size of the complexes between DNA and the polymers were measured. For both polymers, the size of the particles were approximately 60 nm.
[0213] Condensation of DNA with L-cystine—1,4-bis(3-aminopropyl)piperazine Copolymer and Decondensation of DNA upon Addition of glutathione:
[0214] Fluorescein labeled DNA was used for the determination of DNA condensation in complexes with L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer. pDNA was modified to a level of 1 fluorescein per 100 bases using Mirus' LabelIT Fluorescein kit. The fluorescence was determined using a fluorescence spectrophotometer (Shimadzu RF-1501 spectrofluorometer) at an excitation wavelength of 495 nm and an emission wavelength of 530 nm (Trubetskoy, V. S., Slattum, P. M., Hagstrom, J. E., Wolff, J. A., and Budker, V. G., “Quantitative assessment of DNA condensation,” Anal Biochem 267, 309-13 (1999), incorporated herein by reference).
[0215] The intensity of the fluorescence of the fluorescein-labeled DNA (10 μg/ml) in 0.5 ml of 25 mM HEPES buffer pH 7.5 was 300 units. Upon addition of 10 μg/ml of L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer, the intensity decreased to 100 units. To this DNA-polycation sample was added 1 mM glutathione and the intensity of the fluorescence was measured. An increase in intensity was measured to the level observed for the DNA sample alone. The half life of this increase in fluorescence was 8 minutes.
[0216] The experiment indicates that DNA complexes with physiologically-labile disulfide-containing polymers are cleavable in the presence of the biological reductant glutathione.
[0217] Mouse Tail Vein Injection of DNA-L-cystine—1,4-bis(3-aminopropyl)piperazine Copolymer and DNA-guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer Complexes:
[0218] Plasmid delivery in the tail vein of ICR mice was performed as previously described. To pCILuc DNA (50 μg) in 2.5 ml H 2 O was added either L-cystine—1,4-bis(3-aminopropyl)piperazine copolymer, guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer, or poly-L-lysine (34,000 MW, Sigma Chemical Company) (50 μg). The samples were then injected into the tail vein of mice using a 30 gauge, 0.5 inch needle. One day after injection, the animal was sacrificed, and a luciferase assay was conducted.
Polycation ng/liver poly-L-lysine 6.2 L-cystine-1,4-bis(3-aminopropyl)piperazine copolymer 439 guanidino-L-cystine1,4-bis(3-aminopropyl)piperazine copolymer 487
[0219] The experiment indicates that DNA complexes with the physiologically-labile disulfide-containing polymers are capable of being broken, thereby allowing the luciferase gene to be expressed.
[0220] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—Pentaethylenehexamine Copolymer (#M69):
[0221] Pentaethylenehexamine ( 4.2 μL, 0.017 mmol, Aldrich Chemical Company) was taken up in 1.0 ml dichloromethane and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (12 μL, 0.068 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 hr. The solution was then removed from dialysis tubing and dried by lyophilization to yield 5.9 mg (58%) of 5,5′-dithiobis(2-nitrobenzoic acid)—pentaethylenehexamine Copolymer.
[0222] Synthesis of 5,5′-Dithiobis(2-nitrobenzoic acid)—Pentaethylenehexamine—Tris(2-aminoethyl)amine Copolymer (#M70):
[0223] Pentaethylenehexamine (2.9 μL, 0.012 mmol, Aldrich Chemical Company) and tris(2-aminoethyl)amine (0.51 μL, 0.0034 mmol, Aldrich Chemical Company) were taken up in 0.5 ml methanol and HCl (1 ml, 1 M in Et 2 O, Aldrich Chemical Company) was added. Et 2 O was added and the resulting HCl salt was collected by filtration. The salt was taken up in 1 ml DMF and 5,5′-dithiobis[succinimidyl(2-nitrobenzoate)] (10 mg, 0.017 mmol) was added. The resulting solution was heated to 80° C. and diisopropylethylamine (12 μL, 0.068 mmol, Aldrich Chemical Company) was added dropwise. After 16 hr, the solution was cooled, diluted with 3 ml H 2 O, and dialyzed in 12,000-14,000 MW cutoff tubing against water (2×2 L) for 24 h. The solution was then removed from dialysis tubing and dried by lyophilization to yield 6.0 mg (64%) of 5,5′-dithiobis(2-nitrobenzoic acid)—pentaethylenehexamine—tris(2-aminoethyl)amine copolymer.
[0224] pH Cleavable Polymers for Intracellular Compartment Release
[0225] A cellular transport step that has importance for gene transfer and drug delivery is that of release from intracellular compartments such as endosomes (early and late), lysosomes, phagosomes, vesicle, endoplasmic reticulum, golgi apparatus, trans golgi network (TGN), and sarcoplasmic reticulum. Release includes movement out of an intracellular compartment into cytoplasm or into an organelle such as the nucleus. Chemicals such as chloroquine, bafilomycin or Brefeldin A1. Chloroquine decreases the acidification of the endosomal and lysosomal compartments but also affects other cellular functions. Brefeldin A, an isoprenoid fungal metabolite, collapses reversibly the Golgi apparatus into the endoplasmic reticulum and the early endosomal compartment into the trans-Golgi network (TGN) to form tubules. Bafilomycin A 1 , a macrolide antibiotic is a more specific inhibitor of endosomal acidification and vacuolar type H + -ATPase than chloroquine. The ER-retaining signal (KDEL sequence) has been proposed to enhance delivery to the endoplasmic reticulum and prevent delivery to lysosomes.
[0226] To increase the stability of DNA particles in serum, we have added to positively-charged DNA-polycation particles polyanions that form a third layer in the DNA complex and make the particle negatively charged. To assist in the disruption of the DNA complexes, we have synthesized polymers that are cleaved in the acid conditions found in the endosome, pH 5-7. We also have reason to believe that cleavage of polymers in the DNA complexes in the endosome assists in endosome disruption and release of DNA into the cytoplasm.
[0227] There are two ways to cleave a polyion: cleavage of the polymer backbone resulting in smaller polyions or cleavage of the link between the polymer backbone and the ion resulting in an ion and an polymer. In either case, the interaction between the polyion and DNA is broken and the number of molecules in the endosome increases. This causes an osomotic shock to the endosomes and disrupts the endosomes. In the second case, if the polymer backbone is hydrophobic it may interact with the membrane of the endosome. Either effect may disrupt the endosome and thereby assist in release of DNA.
[0228] To construct cleavable polymers, one may attach the ions or polyions together with bonds that are inherently labile such as disulfide bonds, diols, diazo bonds, ester bonds, sulfone bonds, acetals, ketals, enol ethers, enol esters, imines, imminiums, and enamines. Another approach is construct the polymer in such a way as to put reactive groups, i.e. electrophiles and nucleophiles, in close proximity so that reaction between the function groups is rapid. Examples include having carboxylic acid derivatives (acids, esters, amides) and alcohols, thiols, carboxylic acids or amines in the same molecule reacting together to make esters, thiol esters, acid anhydrides or amides.
[0229] In one embodiment, ester acids and amide acids that are labile in acidic environments (pH less than 7, greater than 4) to form an alcohol and amine and an anhydride are use in a variety of molecules and polymers that include peptides, lipids, and liposomes.
[0230] In one embodiment, ketals that are labile in acidic environments (pH less than 7, greater than 4) to form a diol and a ketone are use in a variety of molecules and polymers that include peptides, lipids, and liposomes.
[0231] In one embodiment, acetals that are labile in acidic environments (pH less than 7, greater than 4) to form a diol and an aldehyde are use in a variety of molecules and polymers that include peptides, lipids, and liposomes.
[0232] In one embodiment, enols that are labile in acidic environments (pH less than 7, greater than 4) to form a ketone and an alcohol are use in a variety of molecules and polymers that include peptides, lipids, and liposomes.
[0233] In one embodiment, iminiums that are labile in acidic environments (pH less than 7, greater than 4) to form an amine and an aldehyde or a ketone are use in a variety of molecules and polymers that include peptides, lipids, and liposomes.
[0234] pH-Sensitive Cleavage of Peptides and Polypeptides
[0235] In one embodiment, peptides and polypeptides (both referred to as peptides) are modified by an anhydride. The amine (lysine), alcohol (serine, threonine, tyrosine), and thiol (cysteine) groups of the peptides are modified by the an anhydride to produce an amide, ester or thioester acid. In the acidic environment of the internal vesicles (pH less than 6.5, greater than 4.5) (early endosomes, late endosomes, or lysosome) the amide, ester, or thioester is cleaved displaying the original amine, alcohol, or thiol group and the anhydride.
[0236] A variety of endosomolytic and amphipathic peptides can be used in this embodiment. A positively-charged amphipathic/endosomolytic peptide is converted to a negatively-charged peptide by reaction with the anhydrides to form the amide acids and this compound is then complexed with a polycation-condensed nucleic acid. After entry into the endosomes, the amide acid is cleaved and the peptide becomes positively charged and is no longer complexed with the polycation-condensed nucleic acid and becomes amphipathic and endosomolytic. In one embodiment the peptides contains tyrosines and lysines. In yet another embodiment, the hydrophobic part of the peptide (after cleavage of the ester acid) is at one end of the peptide and the hydrophilic part (e.g. negatively charged after cleavage) is at another end. The hydrophobic part could be modified with a dimethylmaleic anhydride and the hydrophilic part could be modified with a citranconyl anhydride. Since the dimethylmaleyl group is cleaved more rapidly than the citrconyl group, the hydrophobic part forms first. In another embodiment the hydrophilic part forms alpha helixes or coil-coil structures.
[0237] pH-Sensitive Cleavage of Lipids and Liposomes
[0238] In another embodiment, the ester, amide or thioester acid is complexed with lipids and liposomes so that in acidic environments the lipids are modified and the liposome becomes disrupted, fusogenic or endosomolytic. The lipid diacylglycerol is reacted with an anhydride to form an ester acid. After acidification in an intracellular vesicle the diacylglycerol reforms and is very lipid bilayer disruptive and fusogenic.
[0239] Synthesis of citraconylpolyvinylphenol
[0240] Polyvinylphenol (10 mg 30,000 MW Aldrich Chemical) was dissolved in 1 ml anhydrous pyridine. To this solution was added citraconic anhydride (100 μL, 1 mmol) and the solution was allowed to react for 16 hr. The solution was then dissolved in 5 ml of aqueous potassium carbonate (100 mM) and dialyzed three times against 2 L water that was at pH8 with addition of potassium carbonate. The solution was then concentrated by lyophilization to 10 mg/ml of citraconylpolyvinylphenol.
[0241] Synthesis of citraconylpoly-L-tyrosine
[0242] Poly-L-tyrosine (10 mg, 40,000 MW Sigma Chemical) was dissolved in 1 ml anhydrous pyridine. To this solution was added citraconic anhydride (100 μL, 1 mmol) and the solution was allowed to react for 16 hr. The solution was then dissolved in 5 ml of aqueous potassium carbonate (100 mM) and dialyzed against 3×2 L water that was at pH8 with addition of potassium carbonate. The solution was then concentrated by lyophilization to 10 mg/ml of citraconylpoly-L-tyrosine.
[0243] Synthesis of citraconylpoly-L-lysine
[0244] Poly-L-lysine (10 mg 34,000 MW Sigma Chemical) was dissolved in 1 ml of aqueous potassium carbonate (100 mM). To this solution was added citraconic anhydride (100 μL, 1 mmol) and the solution was allowed to react for 2 hr. The solution was then dissolved in 5 ml of aqueous potassium carbonate (100 mM) and dialyzed against 3×2 L water that was at pH8 with addition of potassium carbonate. The solution was then concentrated by lyophilization to 10 mg/ml of citraconylpoly-L-lysine.
[0245] Synthesis of dimethylmaleylpoly-L-lysine
[0246] Poly-L-lysine (10 mg 34,000 MW Sigma Chemical) was dissolved in 1 ml of aqueous potassium carbonate (100 mM). To this solution was added 2,3-dimethylmaleic anhydride (100 mg, 1 mmol) and the solution was allowed to react for 2 hr. The solution was then dissolved in 5 ml of aqueous potassium carbonate (100 mM) and dialyzed against 3×2 L water that was at pH8 with addition of potassium carbonate. The solution was then concentrated by lyophilization to 10 mg/ml of dimethylmaleylpoly-L-lysine.
[0247] Characterization of Particles Formed with citraconylated and dimethylmaleylated Polymers
[0248] To a complex of DNA (20 μg/ml) and poly-L-lysine (40 μg/ml) in 1.5 ml was added the various citraconylpolyvinylphenol and citraconylpoly-L-lysine (150 μg/ml). The sizes of the particles formed were measured to be 90-120 nm and the zeta potentials of the particles were measured to be −10 to −30 mV (Brookhaven ZetaPlus Particle Sizer).
[0249] To each sample was added acetic acid to make the pH 5. The size of the particles was measured as a function of time. Both citraconylpolyvinylphenol and citraconylpoly-L-lysine DNA complexes were unstable under acid pH. The citraconylpolyvinylphenol sample had particles>1 μm in 5 minutes and citraconylpoly-L-lysine sample had particles>1 μm in 30 minutes.
[0250] Synthesis of Glutaric Dialdehyde—Poly-Glutamic acid (8 mer) Copolymer
[0251] H 2 N-EEEEEEEE-NHCH 2 CH 2 NH 2 (5.5 mg, 0.0057 mmol, Genosys) was taken up in 0.4 ml H 2 O. Glutaric dialdehyde (0.52 μL, 0.0057 mmol, Aldrich Chemical Company) was added and the mixture was stirred at room temperature. After 10 min the solution was heated to 70° C. After 15 hrs, the solution was cooled to room temperature and dialyzed against H 2 O (2×2L, 3500 MWCO). Lyophilization afforded 4.3 mg (73%) glutaric dialdehyde-poly-glutamic acid (8 mer) copolymer.
[0252] Synthesis of Ketal from Polyvinylphenyl Ketone and Glycerol
[0253] Polyvinyl phenyl ketone (500 mg, 3.78 mmol, Aldrich Chemical Company) was taken up in 20 ml dichloromethane. Glycerol (304 μL, 4.16 mmol, Acros Chemical Company) was added followed by p-toluenesulfonic acid monohydrate (108 mg, 0.57 mmol, Aldrich Chemical Company). Dioxane (10 ml) was added and the solution was stirred at room temperature overnight. After 16 hrs, TLC indicated the presence of ketone. The solution was concentrated under reduced pressure, and the residue redissolved in DMF (7 ml). The solution was heated to 60° C. for 16 hrs. Dialysis against H 2 O (1×3L, 3500 MWCO), followed by Lyophilization resulted in 606 mg (78%) of the ketal.
[0254] Synthesis of Ketal Acid of Polyvinylphenyl Ketone and Glycerol Ketal
[0255] The ketal from polyvinylphenyl ketone and glycerol (220 mg, 1.07 mmol) was taken up in dichloromethane (5 ml). Succinic anhydride (161 mg, 1.6 mmol, Sigma Chemical Company) was added followed by diisopropylethyl amine (0.37 ml, 2.1 mmol, Aldrich Chemical Company) and the solution was heated at reflux. After 16 hrs, the solution was concentrated, dialyzed against H 2 O (1×3L, 3500 MWCO), and lyophilized to afford 250 mg (75%) of the ketal acid.
[0256] Particle Sizing and Acid Lability of Poly-L-Lysine/Ketal Acid of Polyvinylphenyl Ketone and Glycerol Ketal Complexes
[0257] Particle sizing (Brookhaven Instruments Corporation, ZetaPlus Particle Sizer, I90, 532 nm) indicated an effective diameter of 172 nm (40 μg) for the ketal acid Addition of acetic acid to a pH of 5 followed by particle sizing indicated a increase in particle size to 84000. A poly-L-lysine/ketal acid (40 μg, 1:3 charge ratio) sample indicated a particle size of 142 nm. Addition of acetic acid (5 μL, 6 N) followed by mixing and particle sizing indicated an effective diameter of 1970 nm. This solution was heated at 40° C. particle sizing indicated a effective diameter of 74000 and a decrease in particle counts.
[0258] Results:
[0259] The particle sizer data indicates the loss of particles upon the addition of acetic acid to the mixture.
[0260] Synthesis of Ketal from Polyvinyl Alcohol and 4-Acetylbutyric Acid
[0261] Polyvinylalcohol (200 mg, 4.54 mmol, 30,000-60,000 MW, Aldrich Chemical Company) was taken up in dioxane (10 ml). 4-acetylbutyric acid (271 μL, 2.27 mmol, Aldrich Chemical Company) was added followed by p-toluenesulfonic acid monohydrate (86 mg, 0.45 mmol, Aldrich Chemical Company). After 16 hrs, TLC indicated the presence of ketone. The solution was concentrated under reduced pressure, and the residue redissolved in DMF (7 ml). The solution was heated to 60° C. for 16 hrs. Dialysis against H 2 O (1×4L, 3500 MWCO), followed by lyophilization resulted in 145 mg (32%) of the ketal.
[0262] Particle Sizing and Acid Lability of Poly-L-Lysine/Ketal from Polyvinyl Alcohol and 4-Acetylbutyric Acid Complexes
[0263] Particle sizing (Brookhaven Instruments Corporation, ZetaPlus Particle Sizer, I90, 532 nm) indicated an effective diameter of 280 nm (743 kcps) for poly-L-lysine/ketal from polyvinyl alcohol and 4-acetylbutyric acid complexes (1:3 charge ratio). A poly-L-lysine sample indicated no particle formation. Similarly, a ketal from polyvinyl alcohol and 4-acetylbutyric acid sample indicated no particle formation.
[0264] Acetic acid was added to the poly-L-lysine/ketal from polyvinyl alcohol and 4-acetylbutyric acid complexes to a pH of 4.5. Particle sizing indicated particles of 100 nm, but at a minimal count rate (9.2 kcps)
[0265] Results:
[0266] The particle sizer data indicates the loss of particles upon the addition of acetic acid to the mixture.
[0267] Synthesis of 1,4-Bis(3-aminopropyl)piperazine Glutaric Dialdehyde Copolymer
[0268] 1,4-Bis(3-aminopropyl)piperazine (206 μL, 0.998 mmol, Aldrich Chemical Company) was taken up in 5.0 ml H 2 O. Glutaric dialdehyde was (206 μL, 0.998 mmol, Aldrich Chemical Company) was added and the solution was stirred at room temperature. After 30 min, an additional portion of H 2 O was added (20 ml), and the mixture neutralized with 6 N HCl to pH 7, resulting in a red solution. Dialysis against H 2 O (3×3L, 12,000-14,000 MW cutoff tubing) and lyophilization afforded 38 mg (14%) of the copolymer
[0269] Particle Sizing and Acid Lability of pDNA (pCI Luc)/1,4-Bis(3-aminopropyl)piperazine Glutaric Dialdehyde Copolymer Complexes (#M140)
[0270] To 50 μg pDNA in 2 ml HEPES (25 mM, pH 7.8) was added 135 μg 1,4-bis(3-aminopropyl)piperazine glutaric dialdehyde copolymer. Particle sizing (Brookhaven Instruments Corporation, ZetaPlus Particle Sizer, I90, 532 nm) indicated an effective diameter of 110 nm for the complex. A 50 μg pDNA in 2 ml HEPES (25 mM, pH 7.8) sample indicated no particle formation. Similarly, a 135 μg 1,4-bis(3-aminopropyl)piperazine glutaric dialdehyde copolymer in 2 ml HEPES (25 mM, pH 7.8) sample indicated no particle formation.
[0271] Acetic acid was added to the pDNA (pCI Luc)/1,4-bis(3-aminopropyl)piperazine glutaric dialdehyde copolymer complexes to a pH of 4.5. Particle sizing indicated particles of 2888 nm, and aggregation was observed.
[0272] Results:
[0273] 1,4-Bis(3-aminopropyl)piperazine-glutaric dialdehyde copolymer condenses pDNA, forming small particles. Upon acidification, the particle size increases, and aggregation occurs, indicating cleavage of the polymeric immine.
[0274] Mouse Tail Vein Injections of pDNA (pCILuc)/1,4-Bis(3-aminopropyl)piperazine Glutaric Dialdehyde Copolymer Complexes
[0275] Four complexes were prepared as follows:
[0276] Complex I: pDNA (pCI Luc, 50 μg) in 12.5 ml Ringers.
[0277] Complex II: pDNA (pCI Luc, 50 μg) was mixed with 1,4-bis(3-aminopropyl)piperazine glutaric dialdehyde copolymer (50 μg) in 1.25 ml HEPES 25 mM, pH 8. This solution was then added to 11.25 ml Ringers.
[0278] Complex III: pDNA (pCI Luc, 50 μg) was mixed with poly-L-lysine (94.5 μg, MW 42,000, Sigma Chemical Company) in 12.5 ml Ringers.
[0279] 2.5 ml tail vein injections of 2.5 ml of the complex were preformed as previously described. Luciferase expression was determined as previously indicated.
[0280] Results: 2.5 ml injections
[0281] Complex I: 3,692,000 Relative Light Units
[0282] Complex II: 1,047,000 Relative Light Units
[0283] Complex III: 4,379 Relative Light Units
[0284] Results indicate an increased level of pCI Luc DNA expression in pDNA/1,4-bis(3-aminopropyl)piperazine glutaric dialdehyde copolymer complexes over pCI Luc DNA/poly-L-lysine complexes. These results also indicate that the pDNA is being released from the pDNA/1,4-Bis(3-aminopropyl)piperazine-glutaric dialdehyde copolymer complexes, and is accessible for transcription.
[0285] Non-Cleavable Polymers
[0286] Many cationic polymers such as histone (H1, H2a, H2b, H3, H4, H5), HMG proteins, poly-L-lysine, polyethylenimine, protamine, and poly-histidine are used to compact polynucleic acids to help facilitate gene delivery in vitro and in vivo. A key for efficient gene delivery using prior art methods is that the non-cleavable cationic polymers (both in vitro and in vivo) must be present in a charge excess over the DNA so that the overall net charge of the DNA/polycation complex is positive. Conversely, using our tail vein injection process having non-cleavable cationic polymer/DNA complexes we found that gene expression is most efficient when the overall net charge of the complexes are negative (DNA negative charge>polycation positive charge). Tail vein injections using cationic polymers commonly used for DNA condensation and in vitro gene delivery revealed that high gene expression occurred when the net charge of the complexes were negative.
[0287] Tail vein injection of pCILuc/polycation complexes in 2.5 ml ringers solution into 25 gram mice as previously described (Zhang et al. Hum Gen Ther 10:1735, 1999). The low ratio of each polycation corresponds to wt:wt ratio of 0.5 polycation:1 DNA (net negative complex). The high ratio of each polycation corresponds to wt:wt ratio of 5 polycation:1 DNA (net positive complex).
[0288] High Efficiency Gene Expression Following Tail Vein Delivery of pDNA/Cationic Peptide Complexes
[0289] Plasmid DNA (pCILuc) was mixed with an amphipathic cationic peptide at a 1:2 ratio (charge ratio) and diluted into 2.5 ml of Ringers solution per mouse. Complexes were injected into the tail vein of a 25 g ICR mouse (Harlan Sprague Dawley, Indianapolis, Ind.) in 7 seconds. Animals were sacrificed after 24 hours and livers were removed and assayed for luciferase expression.
[0290] Complex Preparation (per Mouse)
[0291] Complex I: pDNA (pCI Luc, 10 μg) in 2.5 ml Ringers.
[0292] Complex II: pDNA (pCI Luc, 10 μg) was mixed with cationic peptide (18 mer KLLKKLLKLWKKLLKKLK) at a 1:2 ratio. Complexes were diluted to 2.5 ml with Ringers solution.
[0293] Tail vein injections of 2.5 ml of the complex were preformed as previously described.
[0294] Luciferase expression was determined as previously shown.
[0295] Results: 2.5 ml injections
[0296] Complex I: 1.63×10 10 Relative Light Units per liver
[0297] Complex II: 2.05×10 10 Relative Light Units per liver
[0298] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. Therefore, all suitable modifications and equivalents fall within the scope of the invention.
1
1
1
18
PRT
Artificial
synthetic peptide
1
Lys Leu Leu Lys Lys Leu Leu Lys Leu Trp Lys Lys Leu Leu Lys Lys
1 5 10 15
Leu Lys
|
Disclosed is a process for transfecting genetic material into a mammalian cell to alter endogenous properties of the cell. The process comprises designing a polynucleotide for transfection. Then the polynucleotide is inserted into a mammalian vessel such as a tail vein or artery. Prior to insertion, subsequent to insertion, or concurrent with insertion the permeability of the vessel is increased thereby the genetic material is delivered to the parenchymal cell altering endogenous properties of the cell.
| 2
|
This is a continuation in part of U.S. patent application Ser. No. 605,998 filed Oct. 31, 1990 now abandoned.
TECHNICAL FIELD
This invention pertains to an apparatus for maintaining railway road beds. In particular, it pertains to equipment for maintaining the ballast used to support the rails and ties of a railway road bed, and a computer-directed control system for remotely actuating the discharge doors of ballast-carrying railroad hopper cars for the controlled distribution of ballast on to a railway road bed.
BACKGROUND ART
Railway road beds must be capable of supporting extremely heavy rolling stock. Road beds have traditionally included closely spaced railroad ties for supporting the railroad rails. The ties in turn are supported by ballast comprising essentially debris-free rock through which rain water can quickly drain.
Maintenance of the ballast in a railway road bed is of primary concern in extending the usefulness of the railway road bed. The ballast must be periodically cleaned to remove mud and debris that accumulates in the ballast and which would otherwise block the drainage of rain water from the railway road bed. Additionally, the quality of a railroad track is closely related to the levelness of the track. The ballast must be periodically tamped or blown underneath the railroad ties to true the level of the track.
Maintenance of a railway road bed by cleaning or tamping the track bed often requires the addition of ballast to the bed. Adding ballast to the track bed by conventional means is a time-consuming, labor intensive, and logistically difficult operation requiring several different crews and the scheduling of several different pieces of maintenance equipment. Additional ballast is initially deposited along the railroad track bed by a ballast car having hoppers for transporting and operating at the appropriate point to deposit ballast. A second crew then passes along the railroad track with a ballast regulating car that distributes the ballast on the railway track bed and picks up excess ballast. Finally, in situations where the excess ballast is too much to reclaim, or is distributed outside the reach of the regulating and reclaiming car, ballast is formed into windrows spaced apart from the railway road bed.
Ballast is discharged from the ballast-carrying hopper cars by a crew member who walks beside the ballast cars. The crew member uses a long metal lever that is placed in a tube attached to the discharge door to be opened or closed. The crew member, while walking along side the moving ballast car, pushes the lever up or down to pivot the door open or closed. The doors are generally oriented directly above a rail and include a chute or chutes that can be pivoted to either side of the rail for depositing ballast to the field side or the gauge side of the rail.
Frequently, when a crew member moves the lever back to its original position to close a discharge door, pieces of ballast become wedged in the opening between the hopper discharge gate and the discharge door. The crew member must push the lever quickly up and down moving the discharge door just enough to free the ballast and close the door before any more ballast becomes wedged. As a crew member works to unblock the discharge door excess ballast may be discharged resulting in the waste of some ballast. Moreover, pushing the lever up and down is physically demanding and the crew member must pay strict attention to safety as he walks along side the moving train. Operation of the ballast discharge doors is particularly dangerous when a hopper door must be quickly closed prior to the ballast car transmitting across a bridge, switch track or other obstacles.
It will also be appreciated that clouds of dust often obscure the ballast car and make an accurate calculation of the amount of ballast discharged through any hopper door over a particular section of rail very difficult to determine. The clouds of dust and noise of ballast discharging make it difficult for crew members to communicate with one another. The inability to readily communicate leads to confusion and inefficient use of manpower.
A railway maintenance system that could deposit ballast, distribute the ballast, and reclaim excess ballast, including excess ballast that would otherwise have to be formed into windrows, would provide decided advantages to the railroad maintenance industry in terms of scheduling, manpower, and ballast wastage. Moreover, a ballast maintenance system that, with limited manpower, could automatically calculate the amount of ballast necessary to maintain the railway, discharge that ballast through remote control of motorized ballast discharge doors, and automatically pinpoint any problems encountered during the process, would greatly enhance the safety and efficiency of railroad ballast distribution operations.
SUMMARY OF THE INVENTION
The ballast distribution, regulation, and reclaiming railroad maintenance device hereof provides for the distribution, regulation, and reclaiming of ballast in a single operation. The equipment broadly includes one or more ballast cars, a regulating and reclaiming car, and a power car for moving the equipment along a railway road bed. The ballast cars include remotely actuated ballast unloading gates. The regulating and reclaiming car includes reclaim wing plows, a track regulator, and shoulder regulators on each side of the car, and a bucket elevator and belt conveyor for transporting reclaimed ballast to a ballast hopper.
The present invention provides a computer-directed control system for calculating and remotely controlling the discharge of ballast from railroad ballast hopper cars in the course of railroad maintenance. The computer-directed control system includes a computer system with a custom computer program for coordinating the discharge of ballast, a radio transmission and reception system for remote activation of ballast unloading gates, and a data feedback system for monitoring the discharge of ballast and for identifying and solving problems therein. A unique communications protocol is provided to ensure positive control over the selection of which of a plurality of discharge doors are actuated at any given time, while minimizing the requirement for communications hardware.
An alternative, semi-automatic control system is also disclosed that provides for remote actuation of ballast discharge doors by an operator carrying a portable transmitter. The portable transmitter provides for the selection of a desired ballast car by number, and includes individual actuation switches for operating the discharge doors of the selected ballast car one at a time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 1a-1c are side elevational views of a ballast distribution, regulation, and reclaiming railroad maintenance device in accordance with the present invention;
FIGS. 2 and 2a-2c are top plan views thereof;
FIG. 3 is a fragmentary, sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is a fragmentary, sectional view taken along the line 4--4 of FIG. 1 with the ballast discharge doors depicted in the open position and ballast being discharged;
FIG. 5 is a rear elevational view of the device in accordance with the invention;
FIG. 6 is a pictorial view of a handheld radio transmitter for use in controlling the position of the ballast hopper discharge doors;
FIG. 7 is a schematic view of a control system in accordance with the present invention;
FIG. 8 is a pictorial view depicting the remote actuation of the ballast discharge doors of a plurality of ballast hopper cars with the use of handheld radio transmitters;
FIG. 9 is a logical flow chart depicting the principal steps of the computer directed control system for the remote actuation of the ballast discharge doors;
FIG. 10 is a flow chart depicting in greater detail the determination of ballast needed step 200 of FIG. 9;
FIG. 11 is a flow chart depicting in greater detail the optimize ballast flow rate step 229 of FIG. 10;
FIG. 12 is a flow chart depicting in greater detail the physical initialization step 202 of FIG. 9;
FIG. 13 is a flow chart depicting in greater detail the transmission step 206 of FIG. 9;
FIG. 14 is a flow chart depicting in greater detail the open or adjust door step 208 of FIG. 9;
FIG. 15 is a flow chart depicting in greater detail the check ballast flow step 210 of FIG. 9;
FIG. 16 is a flow chart depicting in greater detail the problem solving step 214 of FIG. 9;
FIG. 17 is a flow chart depicting in greater detail the transmitter override step 332 of FIG. 16; and
FIG. 18 is a flow chart depicting in greater detail the ballast door override step 338 of FIG. 16.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, a ballast distribution, regulation, and reclaiming railroad maintenance device 10 in accordance with the present invention broadly includes a plurality of ballast hopper cars 12, 14, 16, a regulating and reclaim car 18, and a power car 20. As indicated by the arrow in FIG. 1, the direction of travel during the ballast distribution process is from the right to left of FIG. 1, with the ballast hopper car 12 at the front of the device 10, and the power car 20 at the rear of the device. While only three ballast hopper cars 12, 14, 16 are depicted in the figures, it will be understood that more than three cars could be used; it is typical to have as many as 60 ballast hopper cars in a single train. It will also be understood that a train could be made up of a plurality of ballast hopper cars and a power car 20, without employing a regulating and reclaim car 18.
The ballast cars 12, 14, 16 are supported along rails R of railroad track bed B by rail engaging wheels 22. Each ballast car 12, 14, 16 includes a front and rear hopper 24, 26 with associated front and rear ballast unloading gates 28, 30. The ballast cars 12, 14, 16 are detachably coupled to each other by coupling mechanisms 32, 34 and the rear ballast car 16 is detachably coupled to the regulating and reclaim car 18 by coupling mechanism 36.
Referring to FIG. 4, ballast gates 28, 30 each include right and left gate assemblies 38, 40. Each of the gate assemblies 38, 40 includes a lowermost opening 42 on the right and left sides respectively of each of the front and rear hoppers 24, 26, a shiftable door 44, and ballast flow sensors 45. The sensors 45 preferably comprise a vibration sensor actuated by vibrations caused by the flow of ballast through its respective door 44. The doors 44 each comprise a pivotable member 46 having a top wall 48 and opposed sidewalls 50, 52. The sidewalls 50, 52 each include right and left ballast chutes 54, 56. Each door member 46 is coupled to an actuating motor 58 and motor shaft 59 by a worm gear 60. The gate assemblies 38, 40 and doors 44 may preferably comprise self-clearing door assemblies of the type described in co-pending U.S. patent application Ser. No. 725,025 filed Jul. 3, 1991, now abandoned, and assigned to the assignee of this application. A gate actuating radio receiver 62 is mounted on each ballast car 12, 14, 16, and electrical connections extend from the receiver 62 to each of the motors 58.
Regulating and reclaiming car 18 is supported along the rails R by rail engaging wheels 64. The frame 66 of the regulating and reclaiming car 18 supports right and left reclaim wing plows 68, 70, track regulator 72, right and left shoulder regulators 76, 78, bucket elevator 80, and belt conveyor 82.
The right and left reclaim wing plow 68, 70 are pivotally coupled to the frame 66 by respective pivot rods 84. The reclaim wing plows 68, 70 each comprise an articulated plowing arm 86. The plowing arms 86 include an inner member 88 pivotally coupled to a sleeve 89 carried by pivot rod 84, and an outer member 90 pivotally coupled to the inner member 88. Pivot rod 84 and sleeve 89 can be selectively shifted up and down, with sleeve 89 received within channel 91 of frame member 93. The inner member 88 includes pivoting clevis 92 for coupling the inner member 88 to the pivot rod 84, plowing face 94, and indirectly to pivot support 96. The outer arm 90 includes clevis 98 for pivotal coupling with the pivot support 96, and plowing face 100.
Track regulator 72 is a conventional track regulator designed for moving ballast from the shoulder of the railway road bed to the center line of the bed. The regulator 72 includes plow faces for engaging the ballast along the shoulder of the road bed and transporting the ballast over the rails R towards the center line along the regulator plow face as the regulator travels along the road bed.
Elevator 80 includes elevator housing 110, having lowermost ballast receiving port 112, and uppermost ballast discharge chute 114. A plurality of ballast holding buckets 116 are arranged along a conveyor chain 118. The elevator housing 110 can be shifted upwardly from the position depicted in FIG. 1 so as to disengage the opening 112 from receiving ballast into the housing 110. Moreover, the opening 112 may be provided with a door 119 to selectively permit the entry of ballast into the housing.
Belt conveyor 82 includes endless web 122 supported on rollers 124. The conveyor 82 includes an upwardly inclined portion extending from a point below the discharge chute 114 of the bucket elevator 80, and a level portion 128. The level portion can be stowed for transit in a vertical position, as depicted in FIG. 1 at 129. Gravity take up assembly 131 maintains the web 122 in a taut configuration when level portion 128 is in the stowed position.
Right and left shoulder regulators 76, 78 comprise conventional shoulder regulators for directing and leveling ballast along the shoulder of the railway road bed. The regulators 76, 78 each include an inwardly directed plow face 130.
Power car 20 is supported along the railroad track rail R by rail engaging wheels 134. The power cap 20 includes operator cab 136, engine compartment 138, and generator 139. The power car 20 is coupled to regulating car 18 by articulated coupling 140.
The generator 139 provides for a source of electrical power for the actuating motors 58, and for the ballast car-mounted radio receivers 62. Alternatively, each car 12 may be provided with its own generator.
Referring to FIG. 6, a hand held radio transmitter 141 for the semiautomatic, individual control of ballast discharge gate assemblies 38, 40 is depicted. The hand held transmitter 141 includes two car selection modules 142 for dialing in two, three digit car numbers. The transmitter 141 also includes door actuating toggle switches 143 for opening and closing a selected discharge door of a selected car's four doors to either the field or gauge side discharge position. An immediate center switch 144 is provided for immediate closing of a selected discharge door. The transmitter 141 is powered by a battery (not shown), and the transmitter 141 includes a switch 145 and an indicator lamp 146.
Referring to FIG. 8, two handheld transmitters 141 can be operated by two maintenance personnel M stationed on either side of the ballast cars 12, 14, 16 (it being understood that the power car 20, though not shown in FIG. 8, would be included in the ballast train). A three digit number is assigned to each ballast car 12, 14, 16. The maintenance person M dials in the number of the ballast car 12 he desires to operate discharge doors 44 on, and operates the toggle switches 143 to shift the position of desired discharge doors on the selected ballast car. The two transmitters 141 operate on different frequencies to avoid interference between the two maintenance persons M. The single receiver 62 on each car 12, 14, 16 scans the two frequencies and locks on to the first frequency it receives. The transmitted message is coded differently depending on the toggle switch 142 selected by the maintenance man M, and the receiver 62 actuates the appropriate motor 58 to the desired door 44, as selected by the toggle switch 142 keyed by the maintenance man M. Position sensors (not shown) could be placed next to each door 44 to sense the open, closed, or partially open status of each door. The sensed position could be transmitted to the handheld transmitter 141 for display to the maintenance personnel M.
Referring to FIG. 7, a computer system 150 for the fully automatic control of ballast discharge gate assembly 38, 40 broadly includes a Central Processing Unit (CPU) 151 and information display monitor 152, memory storage 154 for storing computer instructions for the present invention and an input device 156 such as a keyboard. The computer system 150 is mounted in the power car 20, and the computer system 150 is coupled to a power car-mounted transmitter 158 for communication of instructions to the ballast car-mounted receivers 62.
In operation, the ballast distribution, regulation, and reclaiming railroad maintenance device 10 having a computer system 150 for the fully automatic control of ballast discharge is transported to a portion of the railway road bed B requiring additional ballast, and operated at a slow speed in a forward direction as indicated by the arrow in FIG. 1. The computer-directed ballast control system 150 calculates the volume of ballast to be unloaded along the railway road bed in response to an operator entering the desired depth of additional ballast. The computer-directed ballast control system 150 then operates the radio transmitter 158 to actuate the opening of front and rear ballast gates 28, 30 of selected ballast cars 12, 14, 16 to deposit the required amount of ballast onto the railway road bed B, and diagnoses any problems during this process. Operation of the computer-directed ballast control system 150 is depicted in flow chart form in FIGS. 9-18.
Referring to FIG. 9, the operator of the system 150 first determines how much ballast to discharge on to the railroad track bed B (step 200). The system 150 verifies the initialization of the physical components of the system (step 202). Next, the system 150 determines which gates 28, 30 to open in order to maintain desired ballast flow rate (step 204). The system 150 transmits instructions for the selected gate or gates 28 of the selected ballast car or cars 12, 14, 16 via radio transmitter 158 (step 206). The motor 58 and worm gear 60 on the discharge gate 28 responds to the instructions by opening, closing, or adjusting the gate 28 (step 208). The system 150 then checks the flow of ballast through the gate 28 (step 210). Next, the system 150 performs a system-wide check for any problems with the ballast gates 28, 30 (step 212). If there are problems with the discharge of ballast, then the system 150 initiates problem-solving sequences (step 214). If there are no problems with the discharge of ballast, then the system 150 tests whether all the ballast has been discharged (step 216). If all the ballast has not been discharged, the system 150 repeats steps 204-216 until the desired volume of ballast has been unloaded. Once the desired volume of ballast has been discharged, the system 150 closes all open discharge gates 28 (step 215) and the routine ends (step 217).
FIG. 10 depicts the operation of the determine ballast to discharge step 200 in detail. The operator first enters the total length of rail R to be maintained (step 218). The operator next inputs the depth of the ballast to be discharged (step 220). In this regard, the desired operation may be a so called "skin-lift" wherein the track is raised approximately three inches, or the operation may be a refurbishment of a skeletonized track bed B wherein nearly all of the ballast is replaced, or thirdly, the operation may be a so called "custom" operation wherein the depth of the ballast added to the bed B is determined as a function of the pre-existing track condition. The operator next enters the ballast calibration, i.e. the size and type (e.g. granite, limestone, taconite tailings) of the stones that will be used as ballast (step 224).
The system 150 calculates the total volume of ballast to be laid on the track bed B (step 226). The operator enters the speed of the railroad maintenance device 10 (step 228). Next the system 150 determines the optimum number of gate openings and which gates 28, 30 to open to maintain the desired ballast flow rate (step 229). The system 150 verifies whether the physical initialization step 202 is complete (step 231). If not, the system 150 waits until the physical initialization step 202 is complete (step 233).
The optimize ballast flow rate step 229 of FIG. 10 is set out in greater detail in FIG. 11. The system 150 first calculates the optimum ballast flow rate through a plurality of gates 28 within the following parameters: the number of ballast cars in the train, the total number of operable ballast gates 28, the size of the ballast gate openings, the approximate ballast flow rates as the gate openings vary from fully open to closed, the volume of ballast available in each car, the desired volume of ballast to be discharged on to the track bed B, the length of the track bed B to be maintained, the distance between the discharge gates 28, the calibration (size) of the ballast stones, the speed of the railroad maintenance device 10, the number of communication paths available between the transmitter 158 and receivers 62 and available manpower (step 230). The speed of the train can be continuously monitored and adjusted during operations to adjust the overall flow rate of ballast through the opened discharged doors. It will be appreciated that, given a particular flow rate, the depth of ballast deposited on to the track bed B is a function of train speed.
The system 150 then displays a list of the more efficient combinations ranked from most efficient to least efficient (step 232). The system 150 classifies combinations as more or less efficient based on the number of active gates 28, i.e. open and discharging ballast, and the degree of each active gate's opening at any given time. The most efficient combinations have the least number of active gates 28 and the gates 28 are open to the fullest degree. These combinations are most efficient because the number of available communication paths between transmitter 158 and receiver 62 limits the number of gates 28 that can be contacted and controlled at any given time and opening gates 28 to the fullest degree discharges the maximum amount of ballast in the shortest amount of time. The operator next chooses the gates 28 to open and the corresponding degree of opening from the list displayed (step 234).
The physical verification step 202 of FIG. 9 is set out in greater detail in FIG. 12. The physical verification step 202 of FIG. 9 requires the operator to verify that the railroad maintenance device 10 includes the total volume of ballast required for discharge. First, the operator enters each ballast car 12, 14, 16 number or code and the size of ballast car (step 236). The operator next enters the amount of ballast and general size of ballast stones in each car 12, 14, 16 into the computer system (step 237). Alternatively, each car 12, 14, 16 can be provided with a load cell (not shown) that automatically measures the weight of ballast in the individual cars, and transmits the weight measurement to the system 150. This information is entered for each car 12, 14, 16 beginning with the first car 12 that will approach the railway track bed B to be maintained and ending with the last car 16 that will pass over the track bed B. The system 150 calculates the volume of ballast (step 238). The system 150 subtracts the volume of ballast in the car 12 from the total volume of ballast needed to maintain the desired flow rate (step 239) in order to determine if more ballast cars are needed in step 252. The system 150 verifies that the radio receiver 62 for the selected ballast car is set to the unique code for that car by asking the operator for verification (step 240). If the receiver 62 has not been set with the selected car's unique codes, the system 150 asks the operator if the receiver 62 can be set (step 242). If the receiver 62 can be set with the selected car's unique codes, the system 150 waits for the operator to set it 62 (step 244). If the operator cannot set the unique codes for the selected car, the system 150 alerts the operator that the selected car will not be activated during ballast distribution (step 243) and the system 150 notes the position of the selected car for calculating the distance between discharge gates (step 245).
The system 150 verifies whether the radio receiver 62 is operational by asking the operator to confirm that the receiver 62 is turned on (step 246). If the receiver 62 is not on, the system 150 asks whether the receiver 62 could be turned on (step 248). If the receiver 62 can be turned on, the system 150 waits for the operator to do so (step 250). If the operator cannot turn on the receiver 62 for the selected car, the system 150 alerts the operator that the selected car will not be activated during ballast distribution (step 243) and the system 150 notes the position of the selected car for calculating the distance between discharge gates (step 245).
The system 150 determines whether the volume of ballast in the cars 12, 14, 16 entered into the computer system 150 is sufficient to maintain the desired flow rate (step 252). If more ballast is needed, the system 150 repeats the process from step 236 through step 252 until the volume of ballast in the individual cars 12 meets or exceeds the total amount of ballast needed to maintain the track bed B. When the volume of ballast in the cars 12, 14, 16 entered into the computer system 150 is sufficient to maintain the desired flow rate, the system 150 informs the operator that the physical verification step is complete (step 254) and the operator starts the railroad maintenance device 10 (step 256). The exact number of ballast cars required to discharge ballast on to a railway track bed B to the desired depth is a function of the desired depth of ballast, the length of the track B to be maintained, the size of the ballast stones, the amount of ballast carried by each car 12 and the desired speed of the railroad maintenance device 10.
The transmit gate instructions step 206 of FIG. 9 is set out in greater detail in FIG. 13. FIG. 13 begins with the operator verifying the number of the selected ballast car or cars and the number of the gate or gates 28 to be activated on the selected car (step 258). Selection of the position of individual gates 28 to discharge ballast to the field side or to the gauge side of the rail R or to the center of the bed is made (step 260). The system 150 transmits that information to the selected car's radio receivers 62 (step 262). The system 150 transmits verification checks as the last part of the transmission (step 264).
The radio receivers 62 on the cars 12, 14, 16 pick up the transmission (step 266). If the received transmission codes match the car number codes, the radio receiver 62 acknowledges receipt of the transmission to the operator (step 272) and locks onto the transmission, blocking out other transmissions (step 274). If the received transmission codes do not match the car number codes, then the receiver 62 ignores the transmission (step 269) and continues to scan for valid transmissions (step 268).
The radio receiver 62 checks whether the transmission is error-free using the verification checks that were sent earlier (step 276). If the transmission is not error-free, the receiver 62 rechecks the transmission to verify the transmission (step 278). If the transmission is still not error-free (step 276, 278), the receiver 62 ignores the transmission (step 269) and continues scanning for a valid transmission (step 268).
Opening and adjusting a gate step 208 of FIG. 9 is set out in greater detail in FIG. 14. In FIG. 14, the current position of the door 44 is displayed to the operator (step 284). If the current door position is not the requested door position (step 286), the system 150 powers the motor 58 and the gears 60 to move the door 44 into the requested position (step 290).
The system 150 checks whether the door 44 can move into the requested position (step 292). Occasionally, ballast may become wedged between the gate opening 42 and the door 44, blocking the door 44 from pivoting and closing the gate opening 42. The system 150 identifies when ballast blocks the door 44 from pivoting freely and alerts the operator (step 298). If ballast does not block the door 44 and the door 44 is not in the requested position, then the system 150 continues to power the motor 58 and the gears 60 to pivot the door 44 into position (step 290). Once the door 44 is in position, the system 150 checks whether the door brake is engaged (step 294), holding the door 44 in place. If the door brake is not engaged, the system 150 applies the brake to prevent the door 44 from moving any further (step 296). The position of the door 44 again is displayed to the operator so the operator may verify the position of the door 44 (step 300).
Once the discharge door 44 is in position, the system 150 checks whether the ballast flow rate is consistent with the door position (step 210). The check ballast flow step 210 of FIG. 9 is set out in greater detail in FIG. 15. First, the vibration sensor 45 is activated (step 302). Next, the system 150 checks that the sensor 45 is working (step 303). If the sensor 45 is not working, the system 150 alerts the operator (step 305) and suggests a manual monitoring of the ballast flow (step 307).
If the sensor 45 is working, sensor readings are communicated to the operator (step 304). The system 150 then checks whether the ballast flow rate is adequate (step 306). The ballast flow is adequate when the ballast flow is consistent with the door position. For example, if the door 44 is in a fully open position, the ballast flow rate should be very positive. If the door 44 is in a fully closed position, the ballast flow rate should be at or near zero. If the ballast flow is adequate, the system 150 determines whether to end the discharge of ballast (step 311). The system 150 will end the discharge of ballast if instructed to close the discharge door 44 or if all the ballast has been discharged. If the system 150 does not end the discharge of ballast, the system 150 continues to display the sensor readings to the operator (step 304).
If the ballast flow is inadequate, the system 150 checks whether there is any ballast being discharged at all (step 308). If no ballast is being discharged, the system 150 alerts the operator and opens another discharge door 44 (step 310). If the sensor 45 shows a significantly higher or lower ballast flow rate than the desired flow rate, the system 150 alerts the operator and opens or closes the door 44 to obtain the desired flow rate.
The system 150 then reviews the process to highlight any ongoing problems (step 212 of FIG. 9). If there are problems, the system 150 initiates problem solving (step 214). The problem solving step 214 of FIG. 9 is set out in greater detail in FIG. 16.
One problem the system 150 might encounter is the failure of a door 44 to pivot and move freely to close or open a gate 28. The system 150 verifies whether all active gates can move freely (step 314). If any doors cannot pivot freely, the system 150 determines that making incremental changes in the position of the door 44 should correct this problem (step 315). The system 150 transmits incremental changes in the position of the door 44 moves (step 316). The system 150 moves the door 44 slightly to loosen any ballast that might be blocking the door's movement (step 317). The system 150 verifies that the door 44 moves freely (step 318). If the door 44 is not moving freely after three attempts (step 319), the system 150 applies the brake (step 320) to lock the door 44 in place before re-calculating the ballast flow without the use of this gate.
The system 150 verifies whether the flow of ballast is adequate through all the active gates 28 (step 321). If the ballast flow is inadequate, the system 150 verifies whether any ballast is being discharged at all (step 322). If no ballast is being discharged, the system 150 alerts the operator (step 324). The system 150 determines that the solution to the absence of ballast is to open a gate with a full hopper 30 to replace the gate with an empty hopper 28 (step 325). The system 150 transmits instructions to open another gate (step 206). The system 150 opens the new gate (step 208) and verifies the ballast flow rate through the new gate (step 210). If an inadequate amount of ballast is being discharged, the system 150 alerts the operator (step 326) and determines that the solution to inadequate ballast flow is to adjust the gate opening (step 327). The system 150 then transmits instructions to adjust the gate opening (step 206), adjusts the gate opening (step 208) and verifies the new ballast flow rate through the adjusted opening (step 210).
The system 150 also verifies whether the transmitter 158 is operational (step 328). If the transmitter 158 is not operational, the system 150 alerts the operator and suggests the operator follow the manual transmitter override routine (step 330). The system 150 displays the transmitter override procedure (step 332).
The system 150 also verifies whether the motor 58 is receiving power in order to move the door 44 (step 334). If there is no power to the motor 58, the system 150 alerts the operator and suggests the operator follow the manual gate override routine (step 336). The system 150 displays the gate override procedure (step 338).
If the system 150 cannot identify the problem (step 340), the system 150 will alert the operator and suggest the operator stop the railroad maintenance device 10 (step 344). In this regard, it will be appreciated that all doors would be programmed to fail in the closed position, and stopping the train would automatically cause all ballast doors to close. If there are no problems, the system 150 assumes everything is functioning properly (step 342) and continues the routine.
The transmitter override step 332 of FIG. 16 is set out in greater detail in FIG. 17. First, the operator must open the override compartment 160 located above the door 44 to be manually operated (step 364). The operator moves the transmitter switch 162 to a manual position (step 366) and moves the door switch 164 to a position corresponding with the desired door position (step 368). The system 150 powers the motor 58 and the gears 60 to move the door 44 into position (step 372). The system 150 verifies whether the door 44 is in position (step 374). Once the door 44 is in position, the operator releases the door switch 164 (step 376) and applies the door brake (step 378).
The door override step 338 of FIG. 16 is set out in greater detail in FIG. 18. First, the operator must open the override compartment 160 located above the door 44 to be manually operated (step 380). The operator moves the transmitter switch 162 to a manual position (step 382) and moves the lever 57 disengaging the door brake (step 382). The operator attaches a hand crank (not shown) to the end of the motor shaft 59 (step 386) and moves the door 44 (step 388). The operator continually checks whether the door 44 is in the desired door position (step 390). If the door 44 is not in position, the operator moves the hand crank again (step 388). Once the door 44 is in position, the operator engages the brake (step 392).
The volume of ballast deposited on bed B can be calculated upon completion of the operation through a direct reading of the weight of the remaining ballast in the cars by the load cells (not shown). Alternatively, the volume of ballast deposited can be indirectly calculated by multiplying the flow rates for each gate by the amount of time each gate was operated.
The reclaim wing plows 68, 70 of the regulating and reclaim car 18 may be extended outwardly and positioned along the ground so that, as the device 10 transmits forwardly, ballast spaced apart from the road bed can be pushed onto the road bed for reclaiming by the track regulator 72. In this regard, it will be appreciated that the ballast captured by the reclaim wing plows 68, 70 could typically be ballast left during a previous ballast distribution operation, and formed into windrows due to the inability of prior art devices to reclaim excess ballast.
As the device 10 continues to move forwardly, the ballast brought into proximity of the railway road bed B by the reclaim wing plows 68, 70 is captured by the track regulator 72, and deposited along the center line of the railway road bed B. The door 120 to the opening 112 of the bucket elevator housing 110 may be opened to receive excess ballast deposited by the track regulator along the center line of the railway road bed B. The buckets 116 capture and lift the excess ballast to the discharge chute 114 of the bucket elevator housing 110. The ballast discharged from the bucket elevator 80 is received onto endless web 122 of belt conveyor 82, and is transported by the belt conveyor 82 to the ballast hopper car 16. Load cells (not shown) within the car 16 provide a measure of the weight of ballast within the car 16 to the computer system 150.
The right and left shoulder regulators 76, 78 capture ballast in the vicinity of the shoulder of the railway road bed, on the field side of each of the rails, that is not captured by the track regulator 72. The ballast captured by the right and left shoulder regulator 76, 78 is smoothed and distributed along the shoulder of the railway road bed B.
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A railroad maintenance device distributes, regulates and reclaims ballast along a railway road bed. The device includes one or more hopper cars for transporting and depositing ballast, a regulating car including a track regulator, a shoulder regulator, and an extensible plow arm for reclaiming ballast deposited at a distance from the shoulder of the road bed. The hopper cars include radio controlled gates for the remote control of ballast depositing operations, and a computer controlled system for optimizing the distribution of ballast according to predetermined parameters. A bucket elevator is located rearwardly of the track regulator for lifting excess ballast from the road bed, and a belt conveyor transports the lifted ballast to a hopper car.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an obstacle game machine comprising a movable sheet having a running area and an obstacle area, and simulated object whose movement is to be controlled by the player. More particularly, this invention relates to an obstacle game machine wherein the player manipulates a control (such as lever or knob) to move the simulated object in a direction across a sheet, which has a running area and an obstacle area and is movable in a given direction, in such a manner that the object passes through the running area or bumps against an obstacle.
2. Description of the Prior Art
A conventional obstacle game machine is a driving game machine found in a game arcade. The player manipulates a control (lever or steering wheel) to control the position of a simulated autmobile on a continuously moving endless rubber belt which has a running area as a runway and an obstacle area consisting of rivers, buildings and race pads on both sides of the runway as well as cars running ahead or in the opposite direction, cars immobilized in the runway due to trouble, and rocks that obstruct the running of the car. To determine if the player is properly steering his automobile, a microswitch is provided at the front as well as on both sides of the body of the automobile. If he makes a mistake in the manipulation of the steering wheel and lets the car hit either the bank formed on the border between the running area and obstacle area of the movable sheet or any obstacle on the runway (such as a rock or other vehicles), one of the microswitches senses the occurrence of trouble by being turned on upon contact with such obstacle.
As described above, the movable sheet of the conventional driving game machine is equipped with a bank and other obstructive elements which cause the microswitch to be turned on, and therefore, it cannot be wound around rollers into a compact roll. On the other hand, there is a limitation to the total length of the sheet if it is designed to run in the form of an endless loop, and therefore, the same scene appears at given intervals of driving to thus reduce the pleasure of the game. Furthermore, since the driving game machine requires a large space for housing the endless sheet, it has been difficult to reduce the size of the machine to make it suitable for home use rather than for use in a game arcade.
SUMMARY OF THE INVENTION
It is therefore one object of this invention to provide an obstacle game machine which has a simple and small-sized mechanism for detecting the entrance of a simulated object into an obstacle area, or the occurrence of an obstruction, of a movable sheet.
It is another object of this invention to provide a simple and small-sized obstacle game machine for home use wherein the movable sheet is free from all projections and other obstructive elements conventionally used to turn microswitches on, to thereby reduce the volume of the sheet in a rolled state.
This invention provides an obstacle game machine wherein a movable sheet having a running area and an obstacle area is moved in a given direction, for example, from up to down or from right to left, and a simulated object to be driven which is movable across said movable sheet in a direction substantially vertical to the running direction of said sheet is moved relative to said sheet through manipulation by the player so that said object passes through the running area while staying away from the obstacle area, said game machine having an obstruction detecting means including an electrically conductive mask which moves in operative association with said movable sheet and includes an obstacle conductive area for detecting entrance of said running object into said obstacle area and a running non-conductive area for detecting the running of said object along said running area, a first electrode in contact with the obstacle conductive area of said conductive mask in operative association with the movement of said running object, said second electrode being in contact with the running non-conductive area of said conductive mask so long as the object is staying away from the obstacle area and being brought into contact with the obstacle conductive area if an obstruction occurs, such an obstruction being detected by the first and second electrodes being allowed to conduct through the obstacle conductive area of said conductive mask.
This invention also provides an obstacle game machine wherein a movable sheet having a running area and an obstacle area is moved in a given direction, for example, from up to down or from right to left, and a simulated object to be driven which is movable across said movable sheet in a direction substantially vertical to the running direction of said sheet is moved relative to said sheet through manipulation by the player so that said object passes through the running area while staying away from the obstacle area, said game machine having an obstruction detecting means including an electrically conductive mask which moves in operative association with said movable sheet and includes an obstacle conductive area for detecting entrance of said running object into said obstacle area and a running non-conductive area for detecting the running of said object along said running area, a first electrode in contact with the obstacle conductive area of said conductive mask and a second electrode which is movable across the conductive mask in operative association with the movement of said running object, said second electrode being in contact with the running non-conductive area of said conductive mask so long as the object is staying away from the obstacle area and being brought into contact with the obstacle conductive area if obstruction occurs, such obstruction being detected by the first and second electrodes being allowed to conduct through the obstacle conductive area of said conductive mask; and an electronic tone generator which limits a sequence of "run" electronic sounds that indicate the running of the object relative to the running area of the movable sheet when the first and second electrodes of the obstruction detecting means are not in a electrically conducting state, and emits sequence of "obstacle" electronic sounds that indicate the entrance of the running object into the obstacle area when said first and second electrodes are allowed to conduct.
This invention further provides an obstacle game machine having a movable sheet driving means including a drive roll and a driven roll which are horizontally and rotatably mounted in a casing, a movable sheet both ends of which are wound around the drive roll, a power unit including an electric motor, a one-way transmission mechanism which engages the power unit with the drive roll only when the electric motor is running in the forward direction, and reverse motion actuating means which, imparts the driven roll reverse rotating energy to move said movable sheet in the reverse direction whereby during forward rotation of the motor, the sheet advances toward said roll, and when the motor is running in the reverse direction, the movable sheet run rapidly toward the driven roll.
While the obstacle game machine of this invention is applicable to a driving game wherein the player steers his simulated automobile to run along a given course of road while staying away from obstacle and obstacle zones such as houses and rice pads on both sides of the road, so that he can safely reach the goal wherein the player maneuvers his tank or infantryman to attack the enemy's territory by dodging obstacles such as land mines and sinks in the field of the combat, as well as to other games by varying the kinds of obstacles and simulated objects to be controlled, the following description of one embodiment of this invention relates to a submarine game wherein the player maneuvers his simulated submarine to float up a V-shaped trench in the surface of the sea by staying away from obstacles such as mines and steep walls of rock beds. The submarine game is modified to a space traveling game by changing the submarine to a spaceship and the obstacles to rockets and meteorites coming from the outer space. It is to be noted that the goal (scoring area) may be positioned at an intermediate point of the movable sheet. But with a driving game, combat game and submarine game, by positioning a goal (scoring area) at the terminating end of the movable sheet, a skilled player can enjoy the game for a longer period of time and only a winner can see the scene of the goal, thus adding to the commercial value of the game machine.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view showing the general outline the submarine game machine incorporating the principle of this invention.
FIG. 2 is a vertical cross section of the submarine game machine shown in FIG. 1.
FIG. 3 is a front view of the submarine game machine of FIG. 1 with the front panel of the casing removed.
FIG. 4 is a cross-section of FIG. 2 taken on the line S--S.
FIG. 5A shows the obverse side of the movable sheet in an unrolled form as dismounted from driven and drive rolls. FIG. 5B shows the reverse side of the same movable sheet which constitutes an electrically conductive mask.
FIG. 6 is a perspective view showing the essential parts of the obstruction detecting means of the submarine game machine of this invention.
FIG. 7 is an electrical circuit diagram of the obstruction detecting means and electric tone generator used in the submarine game machine of this invention.
FIG. 8 is a perspective view showing the mechanism for switching between forward and reverse transmissions wherein a control lever is manipulated at adjust the position of a submarine from right to left and vice versa.
DETAILED DESCRIPTION OF THE INVENTION
This invention will now be described in detail by reference to the embodiment shown in the accompanying drawings. FIG. 1 is a general view of the submarine game machine incorporating the principle of this invention, wherein the front panel (1a) of the casing (1) is provided with a window (2) through which part of a movable sheet (3) and a simulated object (a simulated submarine) (4) can be seen. In FIG. 1, (5) is a control lever and (6) is a start-up lever. The machine casing (1) houses movable sheet driving means (Y), a mechanism (X) for controlling the movement of the submarine (4), obstruction detecting means (Z), and an electronic control unit (7) including an electronic tone generator, all of which will be described below.
With reference to FIGS. 2 and 3, the movable sheet driving means (Y) consists of a drive roll (9) which is horizontally and rotatably mounted at the lower portion of the casing (1), a driven roll (8) which is horizontally and rotatably mounted at the upper portion of the casing (1), a movable sheet (3) both ends of which a wound around the drive roll (9) and driven roll (8), a power unit (10) including an electric motor (10a) and a reducing gear, a one-way transmission mechanism (11) which engages the power unit (10) with the drive roll (9) only when the electric motor (10a) is running in the forward direction, and reverse motion actuating means (12) which, as the movable sheet (3) is accumulated by the drive roll (9), imparts the driven roll (8) reverse rotating energy to rotate said roll, or move the sheet (3), in the reverse direction. During forward rotation of the motor (10a), the sheet (3) is wound around the drive roll (9) and when the motor is running in the reverse direction, the drive roll (8) idles and the reverse motion actuating means (12) causes the driven roll (8) to rotate in reverse direction, and this causes the movable sheet (3) to run rapidly toward the driven roll (upward in FIGS. 1 to 3) by being accumulated by said roll.
The reverse motion actuating means (12) consists of gears (G1)(G2), a pulley (13) integral with a gear (G2), a rope (14) wound on said pulley, and a spring (15), one end of which is secured to the rope and the other end of which secured to the side wall (1b) of the casing (1). The one-way transmission mechanism (11) comprises the power unit (10), having a shaft (16) to one end of which is loosely mounted the base of an arm (17), and power output gear (18), fixed to the shaft (16), is kept engaged with an intermediate gear (19) which is rotatably supported on one end of the arm; when the arm (17) is positioned as shown by the phantom line in FIG. 2, the one-way transmission mechanism (11) causes the output gear (18) to engage the drive gear (20) in the forward direction, and by the reverse running of the motor (10a), the arm (17) rotatably shifts to the position indicated by the solid line in FIG. 2, to thereby disengage the output gear (18) from the drive gear (20). When the arm (17) is in the position indicated by the solid line, the pawl (6a) of the start-up lever (6) is in engagement with the end (17a) of the arm. If the lever (6) is depressed, the pawl (6a) pushes the end (17) up, whereupon a switch (17b) operatively associated with the arm (17) is turned on to start the forward running of the motor (10a), and the rotational force of the output gear (18) causes the gear (19) to revolve around said output gear as it comes closer to the drive gear (20) until it is in the position indicated by the phantom line, thus permitting the drive roll (9) to transmit the forward motion of the motor (10a) to the driven roll (8).
The mechanism (X) for controlling the movement of the submarine (4) is now described with reference to FIGS. 4, 6 and 8. To a supporting plate (21) fixed to the rear panel (1c) of the casing, both ends of each of two parallel and horizontal guide rods (22),(22) are fixed. The guide rods (22),(22) are passed through holes (24), (25) of sliding members (23) to make said members slidable along said rods. A vertical plate (26) integrally formed with or attached to the rear end of each sliding member (23) has a disc in its upward extention. The disc serves as a simulated submarine (4) which is moved from right to left and vice versa through the horizontal movement of the sliding members (23). As shown in FIG. 8, a rope (31) is wound round pulleys (27),(27) rotatable supported on the supporting plates (21),(21) and pulleys (29), (30) fixed to a drive vertical shaft (28), and part of the rope (31) is fastened to the vertical plate (26), and like a dial plate of a radio used for frequency tuning, the rotational movement of the drive vertical shaft (28) is converted to a horizontal movement of the vertical plate (26), hence the submarine (4). The drive vertical shaft (28) is engaged via a two-way transmission mechanism (33) with an intermediary shaft (32) coupled to the motor (10a).
With reference to FIG. 8, the transmission mechanism (33) has a drive member (34) wherein a pair of drive discs (34a), (34b) that engage the intermediary shaft (32) only in the rotational direction of the drive shaft (28) so that they are horizontally movable in the axial direction of the intermediary shaft (32) and are integrally joined by a cylindrical member (34c). The drive member (34) is horizontally moved by an operating disc (35) rotatably connected to the tip of an operating shaft (5a) that can be moved back and forth by manipulating the control lever (5), so that a driven disc (36) fixed to the lower end of the drive vertical shaft (28) is brought into contact with either drive disc (34a) or (34b) to thereby rotate the drive shaft (28) in a desired direction. In this manner, the submarine (4) is rendered movable to the left (in the direction indicated by the arrow f1) or to the right (in the direction indicated by the arrow f2) via the rope (31).
In FIG. 8, there is a shown a knob (44) for changing the horizontal travelling speed of the submarine in playing the game. Said knob (44) is rotatably turned to move upwardly and downwardly a vertical drive shaft (28) and an operating disc (36) which is fixedly mounted at the lower end of said shaft (28), and to slidably move the point of contact of said operating disc (36) with drive disc (34a) or (34b) between the circumference and the center so that the ratio of transmitting speed between an intermediate shaft (32) and the vertical drive shaft (28) is changed in order to change the horizontal travelling speed of submarine (4) accordingly. As stated avove, the grade of difficulty in operating the submarine (4) is selectively changeable.
As shown in FIG. 5A, the obverse side (3a) of the movable sheet (3) is divided into a running area and an obstacle area. In the illustrated embodiment, a running area (A) is a trench minus the effective range of each mine (b1), and an obstacle area (B) is the steep walls of rock beds plus the effective range of each mine (b2). The movable sheet terminates with a scene at the surface of the sea (C) which is the goal of the game.
As shown in FIG. 5B, the reverse side (3b) of the movable sheet (3) has its shadowed portion rendered electrically conductive by the printing of ink that contains metal powder or by lamination of a metal foil to provide an electrically conductive mask for generating detection signals, and the resulting conductive mask has a game zone (L) which is divided into an obstacle conductive area (Q) and a running non-conductive area (P) which are similar to the corresponding obstacle areas (B) and running areas (A) of the obverse side (3a). As will be described below, a first electrode (38) is used to detect the center of the submarine (4), and so, the width of the running non-conductive area (P) that acts on the first electrode (38) is smaller than that of the running area (A) of the obverse side (3a) by the scale of reduction by which the width of said electrode (38) is reduced from the size of the submarine (4). The point at which the first electrode (38) acts on the reverse side (electrically conductive mask) (3b) differs from the position of the submarine with respect to the obverse side (3a) in the direction of movement of the sheet (3). To be more specific, as is clear from the comparison of FIG. 5A and 5B, the reverse side (3b) precedes to obverse side (3a) and right and left are reversed for (3a) and (3b). Continuous to the terminating end of the running non-conductive area (P) is an electrically conductive portion where a rewinding signal mark (R) is formed. One marginal edge (M) of the game zone (L) is set aside for a "run" tone zone which is provided with a sequence of "run" tone marks (S) spaced by non-conductive portions, and the other marginal edge (N) is reserved as a goal signal zone which is provided with an electrically conductive goal signal mark (T) at the terminating end of the running non-conductive area (P) and adjacent to the signal mark (R).
The obstruction detection means (Z) consists of the reverse side (conductive mask) (3b) having the above described running non-conductive area (P) and the obstruction conductive area (Q), the first electrode (38) which, as shown in FIGS. 6 and 7, is opposite the reverse side (3b) of the sheet (3) wound around the drive roll (9), and a pair of right and left second electrodes (39). The means (Z) also includes a third electrode (40) disposed in a position where it can contact the "run" tone mark (S) and a fourth electrode (41) disposed in a position where it can contact the goal signal mark (T).
The above described electrodes (38),(39),(40) and (41) are connected to an electronic control unit (7) which includes a motor control circuit including a switching element for switching between the forward and reverse running of the motor (10a) by switching between terminals of a battery (43) to the motor and for controlling the start and stop of the motor by making and breaking the connecting between the motor and the battery, and an electronic tone generator circuit for selectively emitting a "run" electronic tone, "obstruction" electronic tone and "goal" electronic tone from a speaker (42).
Said electronic tone generator circuit, the electrodes (38), (39), (40), (41), the "run" tone mark (S), signal mark (R) and goal signal mark (T) on the electrically conductive mask (3b) and the speaker (42) are the elements that constitute the electronic tone generating means.
The obstacle game machine of this invention described above is operated by the following procedure. Depress the start-up lever (6) to turn the start-up switch (17b) on, upon which the motor (10a) starts to run in the forward direction to rotate the drive roll (9) in the forward direction. This causes the movable sheet (3) to be accumulated by the drive roll (9), resulting in downward movement of the sheet (3). Although the vertical position of the submarine (4) remains unchanged, downward movement of the sheet (3) causes the submarine to appear to the player as if it were floating up to the surface of the sea. The player manipulates the control lever (5) to change the horizontal position of the submarine (4) so that it can safely pass through the running area as it floats up to the surface of the sea.
As long as the submarine (4) keeps safely going through the running area (A), the drive roll (9) continues to run in the forward direction to accumulate the sheet (3), whereas in the reverse motion actuating means (12) the rope (14) is woud round the pulley (13) to stretch the spring (15) until is energized for reverse movement of the sheet (3) As the sheet (3) is being accumulated by the drive roll (9), the third electrode (40) reads the "run" tone mark (S) to send intermittent signals to the electronic control unit (7) including the electronic tone generator circuit which then emits intermittent electronic sounds ("run" electronic sounds) "Pip, Pip, Pip . . . " from the speaker (42). If no "run" tone mark (S) is to be provided on the reverse side (3b) of the movable sheet (3), intermittent sounds can be generated either by an electronic circuit which generates intermittent signals during the rotation of the motor (10a) in the forward direction or by a switch disc which rotates only when the motor (10a) and drive roll (9) are running in the forward direction and which is brought into contact with an electrode for producing intermittent signals.
If the submarine (4), emerging up to the surface of the sea, rams a mine (b1) or the steep walls of rock beds (b2), the first electrode (38) contacts the obstacle conductive area (Q) of the electrically conductive mask (3b) to allow both the first and second electrodes (38) and (39) to conduct. In response to the resulting conducting state, the electronic control unit (7) emits from the speaker (42) "obstruction" electronic sounds such as "Bum! Sweesh" representing the falling of the submarine (4) instead of the "run" electronic tone, "Pip, Pip, Pip . . . ", and at the same time, it switches the terminals of the battery (43) to the motor (10a) to rotate the motor in the reverse direction, upon which the one-way transmission mechanism (11) disengages the drive roll (9) from the motor (10a), followed by the switch (17b) being turned off. Then, the reverse motion actuating means (12) rewinds the movable sheet (3) back to the starting point of the game, where the player again challenges by depressing the start-up lever (6).
If the submarine (4) reaches the final goal (sea level C) or enters a halfway scoring area, the fourth electrode (41) contacts the goal signal mark (T) to actuate the electronic control unit (7) to emit a "Goal" electronic tone as well as to generate signals for actuating a score display device for additional points and total points. At the same time, the first electrode (38) contacts the rewinding signal mark (R) to reverse the rotation of the motor (10a) until the movable sheet (3) is returned to the starting point. In the case, not only the first and second electrodes (38), (39) but also the fourth electrode (41) are allowed to contact, and accordingly, only the "goal" electronic tone, rather than the obstruction electronic tone, is emitted.
While the above illustrated embodiment uses the reverse side (3b) of the movable sheet (3) as an electrically conductive mask, it is to be understood that the mask may be the surface of a separate signal generating sheet which moves in conjuction with the movement of the sheet (3). This modification is advantageous in that the width and length of the separate signal generating sheet can be reduced as compared with the movable sheet (3) and so, by shortening the span of the respective electrodes, the obstruction detecting means can be made smaller.
As described in the foregoing, the obstruction detection means (Z) of this invention consists of an electrically conductive mask having a running non-conductive area and an obstacle conductive area, and first and second electrodes contacting these two areas of the conductive mask, respectively and therefore, as compared with the mechanical detection system, it provides a reliable electrical detection of obstructions (failures) in an obstacle game. In addition, it generates detection signals that facilitate the operation of an electronic tone generator and a failure times adder which clearly indicate success or failure of the game, thus adding to the pleasure of the obstacle game.
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An obstacle game machine wherein a movable sheet having a running area and obstacle area is moved in a given direction, and a simulated objects to be driven is moved relative to said sheet through manipulation by the player so that said object passes the running area while staying away from the obstacle area. Said game machine comprising an obstruction detecting means having an electrically conductive mask which moves in operative association with said movable sheet and includes an obstacle conductive area for detecting entrance of said running object area and a running non-conductive area for detecting the running of said object along said running area, a first electrode in contact with the obstacle conductive area of said conductive mask and a second electrode which is movable across the conductive mask in operative association with the movement of said running object.
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FIELD OF THE INVENTION
The present invention relates to low cost wedge anchor bolts of the type commonly used to mount metal structures to concrete.
BACKGROUND
An example is shown in FIG. 1 . A low cost wedge anchor bolt 2 has a screw 4 with a screw-head 4 a and a shank 4 b . An expandable cage 6 is coaxially disposed around the shank 4 b , and the shank 4 b has a threaded end for engaging the internal threads of a wedge 8 at the distal end of the shank. An insertion portion 9 of the bolt 2 , defined by the shank 4 b , cage 6 , and wedge 8 , is inserted into a drilled hole in the structure to which the anchor bolt is to be anchored.
Turning the screw 4 in one direction, typically clockwise, threads the shank 4 b further into the wedge 8 , drawing the wedge into the cage 6 and thereby causing the cage to expand. Continuing to turn the screw in the same direction eventually results in the cage 6 being expanded sufficiently tightly against the interior surface(s) of the hole to result in a frictional anchoring of the insertion portion 9 therein.
Low cost wedge anchor bolts like that shown in FIG. 1 can be used to provide fall protection for construction workers constructing buildings formed of concrete walls, floors, or ceilings. For that purpose a piece of “bolt attachment” hardware is provided (not shown in FIG. 2 ) allowing for a worker's connection with the anchor bolt. Typically, the bolt attachment hardware is a plate having two through-apertures, one through which the screw 4 extends, for capturing and thus securing the bolt attachment hardware behind the screw-head and the wall (or ceiling, or other surface) into which the hole is drilled, and the other for allowing the user to connect with the anchor bolt via a clip known as a “carabiner.” Typically, the worker is wearing a harness and the harness is connected with the bolt attachment hardware via a lanyard having a carabiner at each end, one for connecting to the harness and one for connecting to the bolt attachment hardware.
Low cost wedge anchor bolts used in providing fall protection for construction workers are generally not needed after construction is complete. Moreover, to maintain the low cost, the components of the basic wedge anchor bolt are typically formed of ordinary steel and are thus susceptible to corrosion. So it is often desirable, and it is often otherwise required by local building codes, to remove them after construction is complete, because corrosion of the bolt will weaken the surrounding concrete, thus weakening the structure.
The problem is that the low cost wedge anchor bolt is not easily removable. Once the bolt is tightened, the cage 6 and wedge 8 become, together, stuck in the hole, and there is no mechanism provided for separating them. Thus while turning the screw in the opposite direction allows for withdrawing the screw 4 from the hole, the cage 6 and the wedge 8 will typically remain behind, requiring another drilling step to drill these parts out of the hole so that complete removal of the anchor bolt can be accomplished.
“Expansion” type anchor bolts have been provided in the prior art that are easily removable. Examples are those described in U.S. Pat. Nos. 7,357,363 and 8,353,653. A comparison of these with the anchor bolt 2 shows the “expansion” type to be a species of wedge anchor bolt, but with significant adaptations providing for ease of removability. For example, in the typical expansion type anchor bolt, the cage is formed of one or more spoons suspended by flexible rods or filaments; the wedge is spring-biased to wedge the spoons against the interior surfaces of the hole; a slidable bushing is provided for transmitting a hammering force applied to the bushing to the wedge for knocking the wedge out of its stuck position, placing the bolt in a relaxed configuration in which the bolt becomes loose in the hole; and a means is provided for remotely pulling the wedge relative to the spoons against the spring-bias to allow the bolt to maintain the relaxed configuration as the bolt is pulled out from the hole.
These adaptations have resulted in the cost of expansion type anchor bolts being significantly higher than that of basic, low cost wedge anchor bolts like that shown in FIG. 1 , to the extent that, even with the additional drilling step, the low cost wedge type anchor bolt is the least costly alternative.
Accordingly there is a need for a basic wedge anchor bolt, i.e., a wedge anchor bolt that is cost competitive with the bolt 2 shown in FIG. 1 , which provides an ease of removability that has heretofore only been available in the relatively expensive “expansion” type anchor bolts.
SUMMARY
Disclosed is an easily removable low cost wedge anchor bolt. The anchor bolt includes a screw member, a wedge member, and a cage member. The screw member has a head defining a proximal end of the screw member, and an elongate shank extending from the head and terminating at a distal end of the screw member. The shank has a threaded end, the head being or having a feature shaped for coupling with a tool so as to render the tool capable of turning the head about an elongate axis of the screw member, thereby either axially advancing or axially withdrawing the threads of the threaded shank. The wedge member is threadably engaged by the threaded portion of the shank. The cage member defines a cavity through which the threaded end of the shank extends and into which at least a portion of the threadably engaged wedge member is allowed to non-forcibly penetrate. The wedge member is shaped in cooperation with the cavity to force the cavity to undergo a radial expansion as a result of being drawn into the cavity by means of advancing the threads of the threaded shank, the wedge member becoming stuck in the cavity as a result.
For ejecting the wedge member from the cavity according to the invention, the screw member includes at least one of (1) one or more depressed portions, and (2) one or more projecting portions, defining a step of abruptly increasing radial dimension of the screw, and the cage member includes one or more corresponding step-engaging portions for making an interference contact with the step when the threads have been withdrawn from the cage and wedge members a sufficient amount, so that further withdrawal of the threads ceases to withdraw the threads relative to the cage member while continuing to withdraw the threads relative to the wedge member, thereby forcing the wedge member distally relative to the cavity.
Preferably, the anchor bolt is limited to screw members having one or more depressed portions for defining the step; more preferably, the one or more depressed portions is a necked-down portion of the screw member; and most preferably, the necked-down portion is substantially cylindrical.
Preferably, in combination with any of the embodiments described above, each of the one or more step engaging portions is or includes a tang depending from the cage member.
Preferably, in combination with any of the embodiments described above, the anchor bolt includes a keeper at the distal-most end of the threaded member, for stopping the wedge member from becoming completely disengaged with the threaded member and thereby preventing the wedge member from being forced away from the threaded member as a result of forcing the wedge member distally relative to the cavity.
Also disclosed is a method for removing an anchor bolt from a hole, where the anchor bolt includes a screw member, a wedge member, and a cage member, the screw member having a threaded end and defining a screw axis, the threaded end of the screw member being threadably engaged into the wedge member, the cage member defining a cavity through which the threaded end of the screw member extends and into which at least a portion of the threadably engaged wedge member is allowed to non-forcibly penetrate. The anchor bolt has been inserted into the hole in a first axial direction parallel to the screw axis, and the wedge member is shaped in cooperation with the cavity to force the cavity to undergo an expansion in one or more directions perpendicular to the screw axis as a result of being drawn into the cavity by means of turning the screw so as to advance the threads of the threaded end, the anchor bolt being thereby wedged in the hole with the wedge member stuck in the cavity.
For ejecting the wedge member from the cavity according to the invention, the method provides a step of turning the screw member in a first radial direction for withdrawing the threads from the wedge member, thereby causing the screw member to translate relative to the cage member in a second axial direction opposite the first axial direction; and a step of stopping the screw member from further axial translation relative to the cage member in the second axial direction while allowing for continued turning of the screw member in the first radial direction, so that further withdrawal of the threads from the wedge member will result in forcing the wedge member in the first axial direction relative to the cavity.
Preferably, during the step of stopping, the method provides a step of continuing to turn the screw in the first radial direction and thereby continuing to withdraw the threads from the wedge member, thereby resulting in forcing the wedge member in the first axial direction relative to the cavity.
It is to be understood that this summary is provided as a means of generally determining what follows in the drawings and detailed description and is not intended to limit the scope of the invention. Objects, features and advantages of the invention will be readily understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an isometric view of a prior art basic wedge anchor bolt.
FIG. 2 is an isometric view of an easily removable low cost wedge anchor bolt according to the present invention.
FIG. 3 is an exploded isometric view of the wedge anchor bolt of FIG. 2 .
FIG. 4 is an isometric view of an alternative wedge according to the invention.
FIG. 5 is a side sectional view showing the anchor bolt of FIG. 2 installed loosely in a drilled hole.
FIG. 6 is a side sectional view of the anchor bolt of FIG. 2 in an anchoring configuration, after having been tightened.
FIG. 7 is a cut-away isometric view of the wedge anchor bolt of FIG. 2 , showing a step formed in a screw according to the invention and a corresponding step-engaging portion of a cage according to the invention, the step-engaging portion being shown looking from the top, the step and step-engaging portion being in a first relative position in which the step-engaging portion is spaced apart from the step.
FIG. 8 is a cut-away isometric view of the wedge anchor bolt of FIG. 2 , showing the step and step-engaging portion of FIG. 7 with the step-engaging portion being shown looking from the side.
FIG. 9 is a cut-away isometric view of the wedge anchor bolt of FIG. 2 , showing the step and step-engaging portion as depicted in FIG. 7 in a second relative position in which the step-engaging portion has made contact with the step, after starting from the first relative position of FIG. 7 and withdrawing the threads of the screw.
FIG. 10 is a cut-away isometric view of the wedge anchor bolt of FIG. 2 , showing the step and step-engaging portion as depicted in FIG. 8 in the second relative position shown in FIG. 9 .
FIG. 11 is a cut-away side elevation of a screw and cage assembly for reference in defining an “abrupt” transition for a step according to the invention.
FIG. 12 is a cut-away side elevation of a screw and cage assembly showing an alternative configuration, compared to that shown in FIGS. 3 and 7 - 10 , for a “necked-down” portion of a screw for defining a step according to the invention.
FIG. 13 is a cut-away side elevation of a screw and cage assembly illustrating a “necked-up” portion of a screw for defining a step according to the invention, for comparison with the “necked-down” portions of FIGS. 3 , 7 - 10 , and 12 .
FIG. 14 is a cut-away side elevation of a screw and cage assembly showing an alternative configuration, compared to that shown in FIG. 13 , for a “necked-up” portion of a screw for defining a step according to the invention.
FIG. 15 is a front elevation, taken along the line 15 - 15 , of the screw and cage assembly of FIG. 14 .
FIG. 16 is a cut-away side elevation of a screw and cage assembly showing a first alternative step-engaging portion to that shown in FIGS. 12-14 , according to the invention.
FIG. 17 is a cut-away side elevation of a screw and cage assembly showing a second alternative step-engaging portion, which is an alternative to the step-engaging portion of FIG. 16 , according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 2 and 3 show a preferred removable low cost wedge anchor bolt 10 according to the present invention. It will be understood that the bolt 10 may be used in any application in which standard prior art wedge anchor bolts are used. However, the bolt 10 is particularly advantageous in applications where it is important to be able to easily remove the bolt when its service life is over.
At least two such applications are (1) to provide fall protection for construction workers such as previously described; and (2) to provide temporary anchor points for rock climbers. Like in the construction application, low cost wedge anchor bolts used for rock climbing are installed in holes drilled into the rock. Once in place, the bolts are exposed to the elements making it even more important to remove them after a time, both to ensure climber safety and to return the rock, as much as possible, to its natural condition. This is particularly so if the rock is ferrous and is therefore particularly susceptible to weakening as a result of corrosion of the anchor bolt.
As is standard in the art, the bolt 10 is preferably provided with bolt attachment hardware 12 having two through apertures—a through aperture 12 a for receiving the screw 14 , and a through aperture 12 b for receiving a caribiner as explained previously. The apertures 12 a and 12 b are both contiguously surrounded by metal, thus preventing any possibility of the screw 14 and the caribiner (assuming no failure of the caribiner itself) escaping from the respective apertures.
Structural support for the bolt 10 is provided by a screw 14 which has a head 14 a at its proximal end. The head 14 a shown is hexagonally shaped, to allow for turning the screw about its elongate axis “L” by use of a standard hex wrench. The head 14 a may have other shapes, or include features such as slots (e.g., for receiving standard bladed or Phillips type screwdrivers) or shaped depressions (e.g., for receiving a standard hexagonally shaped key or Allen wrench) allowing for the same functionality, that is, for turning the screw by use of a standard hand tool.
The screw 14 has an elongate shank 14 b which extends from the head 14 a and terminates at the distal end of the screw 14 . The shank 14 b has a threaded end 14 b 1 ; turning the screw 14 in one radial direction, e.g., clockwise about the axis L, advances these threads in a first axial direction, along the axis L, toward the distal end of the screw, whereas turning the screw in the opposite radial direction withdraws the threads, in a second axial direction opposite the first axial direction, toward the proximal end of the screw.
So far, the screw 14 as described can be any ordinary bolt. To form a low cost wedge anchor bolt, the screw 14 is combined with two more parts, namely a wedge 16 and a cage 18 .
The external threads of the threaded end 14 b 1 of the shank 14 b of the screw 14 are for engaging complementary internal threads of the wedge 16 . The wedge 16 functions in cooperation with a cavity 18 a of the cage 18 to force the cavity to undergo a radial expansion, i.e., in directions perpendicular to the axis L, as a result of being drawn into the cavity by means of advancing the threads of the threaded shank. The cavity and, especially, the wedge could have many different shapes to perform this function. Typically, the cavity is (internally) cylindrical and the wedge is (externally) frustoconical, as in the preferred embodiment shown in FIGS. 2 and 3 . Thus the description so far describes both the bolt 10 and the prior art bolt 2 shown in FIG. 1 . And generally, there is no intention to limit the invention to particular shapes or configurations.
However, with reference to FIG. 4 , an alternative wedge 17 having a series of spaced-apart gripping elements, here axially extending depressions or, in a related alternative (not shown), protusions, provides for an improved grip on the internal surface of the cavity, and thus can be advantageous to reduce the tendency of the wedge to spin inside the cavity as the threads are being advanced. Such gripping elements—depressions or protusions—could be provided in any number of shapes, patterns and configurations, and could be provided on the interior surface of the cavity as well, alone or in combination with gripping elements on the wedge itself.
The cavity is provided at the distal end of the cage 18 . It can be adapted for forced radial expansion in any number of ways known in the art. Generally, two or more lines of weakening 18 b are provided. The lines of weakening typically run axially, i.e. parallel to the axis L, and are typically apertures that pass through the sides of the cage. However, it is not essential for the lines of weakening to run axially; for example, they could be spirals. It is, however, preferable for lines of weakening to run more axially than radially (perpendicular to the axis L). It is also not essential for a line of weakening to be formed of holes passing through the sides of the cage; for example, it could be a line along which the material of which the cage is formed is thinner, or weaker. Further, it is not essential for a line of weakening to be continuous; for example, it could be a line of perforations. Further still, it is not essential to provide weakening along lines; for example, perforations or apertures could be provided in any desired pattern, so long as sufficient physical integrity of the cavity remains to provide for the anchoring function. Unless otherwise indicated, there is no intention to limit the invention in regards to the configuration of the cavity and wedge combination for achieving the function of forced radial expansion of the cavity by the wedge as a result of drawing the wedge farther into the cavity.
The resulting anchoring is illustrated by FIGS. 5 and 6 . FIG. 5 shows the bolt 10 just after insertion into a hole 20 which has been drilled into a concrete or rock wall 23 . The bolt is, at this point, loose in the hole.
FIG. 6 shows the same bolt after it has been fully tightened, by turning the head 14 a of the screw in the direction required to advance the threads of the threaded end of the screw into the threads of the wedge. When fully tightened, the cavity is forcibly radially expanded, so that outer surface(s) of the cavity is (are) pressed hard against the internal surface(s) of the hole, and the bolt is gripped by the wall 23 as a result of friction between the outer surface of the cage 16 and the inner surface of the hole.
The cavity 18 a resists being forcibly expanded due to its own structural integrity, and once it has been expanded sufficiently to seat against the interior surface of the hole, it resists being expanded further by the interior surface of the hole. Thus, tightening the bolt ultimately results in jamming the wedge 16 in the cavity 18 a , with the wedge becoming stuck in the cavity.
Loosening the bolt requires turning the head 14 a of the screw in the opposite direction that was required for tightening the bolt, thereby withdrawing the threads. Because the wedge is jammed in the cavity, the threads withdraw from the wedge, and the screw 14 starts to back out of the cage 16 . If not for the feature described immediately below, the screw would continue to back out of the cage until it becomes fully separated from the bolt, leaving the cage and wedge behind, stuck in the hole as in the prior art.
To solve this problem in accord with the invention, the screw 14 includes a “necked-down” portion 14 c , which can be seen in FIG. 3 , which results in a step 14 c 1 of abruptly increasing width of the screw; and cooperating with this, the cage 16 includes a corresponding one or more step-engaging portions 18 c for interferingly engaging with the step 14 c 1 , once the screw 14 has backed out of the cage 16 a sufficient amount for the step to come into interfering contact with a free end 18 c 1 of a step-engaging portion.
FIGS. 7 and 8 show these features prior to the screw 14 being backed out of the cage 16 sufficiently to bring the step into contact with the step-engaging portions of the cage; and corresponding FIGS. 9 and 10 show the same features after such contact has been made, at which point further relative axial movement of the screw relative to the cage is halted. That is, the threads will cease to significantly advance (or withdraw) relative to the cage.
Advantageously, as the threads are still threadably engaged with the wedge 16 , continuing to turn the screw 14 so as to continue to withdraw the threads now forces the wedge in the opposite direction, toward the distal end of the screw, thereby forcibly ejecting it from the cavity 18 a.
Ejecting the wedge 16 from the cavity results in a relaxation of the grip provided by the cage on the interior surface of the hole, allowing the screw 14 to be pulled from the hole, carrying the cage 18 along with it as a result of the interfering relationship between the step of the screw and the step-engaging portion(s) of the cage.
As the name implies, the step defines a region over which there is a transition, more particularly an increase, in the radial dimension of the screw. With reference to FIG. 11 , this transition is preferably “abrupt,” meaning that, over a region of “X” units of measure along the axis “L,” measured where the screw is adapted to make contact with the step-engaging portion, the radial dimension “R” increases at least 2×, more preferably at least 5×, and most preferably at least 10×. The reason for preferring a more abrupt transition is to confer the greatest mechanical advantage on the step-engaging portion(s). A perfect step is where “X” is zero, and X could also be negative (measured from the point “P” in the direction opposite the “+” direction).
To ensure that the wedge 16 is not ejected so far from the cavity as to become disengaged with the threads of the screw 14 , and therefore to reduce the risk that the wedge will be left behind in the hole, a keeper 22 , such as a common circlip, is preferably attached to the screw 14 at its distal end in a standard manner. Providing a keeper is preferable but not essential. If the threaded end of the bolt is not too short, the wedge will remain threaded to the screw after it has been ejected from the cavity.
To maintain low cost, the one or more step-engaging features 18 c are preferably integrally formed parts of the cage 18 . As best seen in FIG. 3 , this is by creating, such as by die cutting, one or more elongate apertures 19 through the cage so as to define one or more elongate edges of the feature 18 c , which as a result become separated from the remaining portions of the cage 18 . The aperture(s) 19 extend only partially around the feature 18 e , so that the feature 18 c remains connected to the cage 18 , such as in the vicinity indicated as 21 , as a cantilevered projection. This projection, because it is cantilevered, may be bent, independently of the surrounding material of which the cage is formed, radially inwardly (toward the axis L), allowing the free end of the tang ( 18 c 1 ) to interfere with the step ( 14 c 1 ).
The word “tang” is the closest English word of which Applicant is aware that describes a step-engaging feature like that described immediately above. According to the standard definition, a “tang” is limited to projecting parts that are “slender.” With reference to the dimensions “a” and “b” in FIG. 3 for the step-engaging feature 18 c , and with reference to the dimension “t” in FIG. 8 of the same feature, there may be an ambiguity as to what is meant by “slender.” As shown, dimensions “a” and “b” are roughly equivalent, and it is to be understood that either dimension could be significantly larger than the other. So the feature 18 c is “slender” with respect to the dimension “t,” being considerably less than either dimensions “a” or “b.”
There may also be an ambiguity as to whether a “tang” as ordinarily defined is limited to projections that are monolithic—in the sense of being connected without joints or seams—extensions of the structures from which they depend.
To resolve these ambiguities, as used herein the term “tang” is defined in its ordinary manner, with the proviso that it is connected to the structure from which it projects without joints or seams, implying that it is formed out of the same block of material of which the cage is formed, and it is slender, meaning for purposes herein that, with reference to its width, length, and depth dimensions as measured along three respective mutually orthogonal axes, at least one of these dimensions is significantly smaller than at least one other of these dimensions, where “significantly smaller” means at least 3 times smaller, more preferably at least 5 times smaller, and most preferably at least 10 times smaller.
The reason for preferring a tang that is more slender can be appreciated by recognizing that, since the tang is formed from the same block of material from which the cage is formed, any material devoted to the tang necessarily subtracts from the material that could have been devoted to the cage. Thus the reason to prefer a tang that is more slender is to minimize the amount of material that is not available for strengthening the cage, to use for the step-engaging function, which requires a significant degree of projection (e.g., a significant dimension “b” as shown in FIG. 3 , or a significant dimension “1” as shown in FIG. 14 ) but not much strength.
FIG. 12 shows an alternative screw 24 and cage 28 , illustrating why it is not important for the necked down portion 24 c of the screw to be cylindrical.
FIG. 13 shows an alternative screw 34 and cage 38 , illustrating an alternative to use of a necked down portion to provide the step. In this case, there is a protruding or “necked up” portion, or projection, 34 c of the screw providing a step 34 c 1 . The portion 34 e could be a removable part, such as a circlip, in which case the screw 34 would have a circumferential groove for receiving the circlip.
FIGS. 14 and 15 show another alternative screw 44 , illustrating a modification of the screw 34 of FIG. 12 . In this embodiment, the screw has a projection 44 c that does not encircle the screw as does the projection 34 c of the screw 34 . Instead, with reference to FIG. 14 , the projection 44 c extends over an arc length “S 1 ” and step-engaging portions 48 e are arranged so that there are no gaps of arc larger than “S 2 ,” where S 2 <S 1 .
The embodiment of FIG. 14 is less preferred than those of FIGS. 12 and 13 because it results in a relative abundance of excess space between the cage and screw, allowing for an excess of undesirable lateral movement of the screw inside the cage.
The embodiment of FIG. 15 is less preferred than that of FIG. 14 because it requires more of the cage to be devoted to the step-engaging function, which tends to weaken the cage if the step-engaging portions are tangs, and which, if the step-engaging portions are attached to the cage with joints or seams, requires more costly manufacturing.
In FIGS. 12-15 , the step-engaging portions ( 28 c , 38 c , 48 c ) are tangs.
An alternative to the tang is shown in FIG. 16 . The screw could be either 14 or 24 , or it could have a different configuration from either of these. In this example the step-engaging portion 58 c is formed by adding metal to the cage. It is not a tang because it connected to the cage with a joint or seam.
Another possible alternative to the tang is shown in FIG. 17 . Again, the screw could be either 14 or 24 or it could have a different configuration from either of these. In this example, the step-engaging portion 68 c is formed by displacing metal of the cage 68 . It is not a tang if it is not slender, and as drawn, it would not be slender unless its measured dimension perpendicular to the plane of the Figure is significantly less than its dimensions “l” and “w” in the plane of the Figure.
As is standard commercial practice in the art of low cost wedge anchor bolts, the screw, cage, and wedge are all preferably formed of carbon steel. However, other metals—indeed other materials (e.g., fiber reinforced plastics)—could be used without departing from the principles of the invention.
Returning to FIG. 3 , preferably the anchor bolt 10 includes a “compression bushing” 25 , which is typically formed of a polymer. The compression bushing 25 has a relatively high compliance as compared to the attachment hardware and the cage 18 and has a substantial thickness allowing for a substantial amount of deformation, qualities which allow it to prevent the attachment hardware 12 from making hard contact with the end 18 d of the cage 18 before seating against the surface 23 a of the structure (see FIG. 6 ). This function could alternatively be performed by a split-ring washer, or any other structure providing the same or similar qualities.
A split-ring washer 26 may also be provided between the screw-head 14 a and the attachment hardware to provide a positive indication to the user of when the anchor bolt 10 is fully tightened.
It is to be understood that, while a specific easily removable low cost wedge anchor bolt has been shown and described as preferred, other configurations could be utilized, in addition to those already mentioned, without departing from the principles of the invention. It should also be understood that, as indicated previously, the concrete anchor point may be used in any application that an anchor point may be used.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions to exclude equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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A wedge anchor bolt having a screw member, a wedge member, and a cage member. The bolt is anchored into a drilled hole by wedging the wedge member in the end of the cage member by turning the screw member, with the result being that the wedge member becomes stuck in the cage member. For ejecting the wedge member from the cavity the screw member includes at least one of (1) one or more depressed portions, and (2) one or more projecting portions, defining a step, and the cage member includes one or more corresponding step-engaging portions for making an interference contact with the step, so that further withdrawal of the threads ceases to withdraw the threads relative to the cage member while continuing to withdraw the threads relative to the wedge member, thereby forcing the wedge member distally relative to the cavity.
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TECHNICAL FIELD
A handle mechanism for operating a vehicle door latch has a handle lever for operating the latching mechanism of a vehicle door latch and a button handle for operating the locking mechanism of the vehicle door latch. The handle mechanism includes a child security lock that disables the handle mechanism so that it cannot unlatch the vehicle door latch. The child security lock is engaged by the handle lever and disengaged by manipulating the handle lever and the button handle in a predetermined sequence.
BACKGROUND OF THE INVENTION
Vehicle door latches typically include a latching mechanism for latching the vehicle door in the closed position and unlatching the vehicle door so that it can be pushed or pulled open. Vehicle door latches also typically include a locking mechanism that disables the latching mechanism after the door is latched in the closed position to prevent unauthorized or inadvertent unlatching and opening of the vehicle door. The latching mechanism typically includes separate links that are attached to respective inside and outside operators such as interior and exterior door handles for operating the latching mechanism. The locking mechanism typically includes separate links that are attached to respective inside and outside operators, such as an interior sill button and an exterior lock cylinder, for operating the locking mechanism. See, for instance, U.S. Pat. No. 5,277,461 granted to Thomas A. Dzurko et al Jan. 11, 1994 for a vehicle door latch of the type described above.
Vehicle door latches have included various ancillary features over the years. One of these features is a child security lock that is engaged to prevent operation of the latching mechanism by the interior door handle or other interior operator. The prior art vehicle door latches with child security locks typically include a decoupling member in the linkage system that connects the vehicle door latch to the interior door handle. The decoupling member is typically manually operated by an independent operator that is either hidden or inaccessible when the vehicle door is closed to prevent young passengers from disengaging the child security lock. However, such an inaccessible operator also prevents adult passengers from disengaging the child security lock and exiting the vehicle. See, for instance, U.S. Pat. No. 5,046,769 granted to Ronald P. Rimby and Rita M. Paulik Sep. 10, 1991 for a door latch coupling arrangement and U.S. Pat. No. 5,308,128 granted to Alfred L. Portelli and Rita M. Paulik May 3, 1994 for a vehicle door latch.
SUMMARY OF THE INVENTION
The object of this invention is to provide an operator for engaging or disengaging a child security lock that is readily accessible from the interior of the vehicle yet deters operation by young passengers.
A feature of the invention is that the operator for the child security lock of the vehicle door latch is part of an interior door handle mechanism for a vehicle door that includes a handle lever for operating the latching mechanism and a button handle for operating the locking mechanism of the vehicle door latch.
Another feature of the invention is that the handle mechanism includes a child security lock that is engaged easily but that requires two-handed operation for disengagement.
Another feature of the invention is that the handle mechanism includes a child security lock that is engaged easily but that requires a sequence of operations for disengagement so as to deter operation by young children.
Still another feature of the invention is that the handle mechanism includes a child security lock that is engaged and disengaged mechanically and thus operates independently of the vehicle electric power supply.
Yet another feature of the invention is that the handle mechanism has a child security lock that can be engaged or disengaged while the vehicle door is open or closed.
Still yet another feature of the invention is that the handle mechanism includes a handle lever that pivots in one direction to operate a door latch and an opposite direction to operate a child security lock and a unique spring arrangement for biasing the handle lever to a neutral or latch position between the two.
These and other objects, features and advantages of the invention will become more apparent from the following description of a preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective rear view of a handle mechanism in accordance with the invention;
FIG. 2 is a front perspective view of the handle mechanism and FIG. 3 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the handle mechanism is in a latched and unlocked condition with the child security lock disengaged;
FIG. 4 is a front perspective view showing the pats in their respective positions when the handle mechanism is in a latched and unlocked condition with the child security lock disengaged;
FIG. 5 is a rear perspective view showing the handle mechanism with the parts in an unlatched position when the handle mechanism is unlocked and the child security lock is disengaged;
FIG. 6 is a rear perspective view showing the handle mechanism with the parts in an unlatched position when the handle mechanism is locked and the child security is disengaged;
FIG. 7 is a front perspective view of the handle mechanism and FIG. 8 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the child security lock is engaged with the locking lever in the locked position;
FIG. 9 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the child security lock is engaged with the locking lever in the unlocked position;
FIG. 10 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the handle lever is pivoted to the unlatch position;
FIG. 11 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the locking lever is pivoted to the locked position while the handle lever is held in the unlatch position;
FIG. 12 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the locking lever is pivoted back to the unlocked position while handle lever is held in the unlatch position;
FIG. 13 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the locking lever is pivoted back to the lock position while handle lever is held in the unlatch position; and
FIG. 14 is a rear perspective view of the handle mechanism showing the parts in their respective positions when the handle lever is released and returns to the neutral or latched position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, FIG. 1 shows a handle mechanism of the invention indicated generally at 10 . Handle mechanism 10 comprises a housing 12 having a pair of integral, vertically spaced pivot gussets 14 and 16 and a cam projection 17 on the back side, a pivot pin 18 that extends through aligned holes in the pivot gussets and a handle lever 20 that is pivotally mounted on housing 12 by pivot pin 18 . Handle lever 20 has a generally flat body or handle 22 with upper and lower arms 24 and 26 protruding from the rear face of the body 22 at one end in perpendicular fashion. Handle 22 lies adjacent the front of housing 12 with upper and lower arms 24 and 26 protruding through respective slots of housing 12 to the back side where journal portions of arms 24 and 26 surround pivot pin 18 .
A coil spring 28 is disposed between the upper and lower arms 24 and 26 and surrounds pivot pin 18 loosely. Coil spring 28 has two tangential ends. End 30 engages abutment 32 of upper arm 24 and opposite end 34 engages abutment 36 of lower arm 26 . Spring ends 30 and 34 also engage housing 12 so that coil spring 28 holds handle lever 20 in a neutral position and returns handle lever 20 to the neutral position when handle lever 20 is pivoted clockwise or counterclockwise as explained below. Handle lever 20 is pivoted from the neutral position shown in FIG. 1 in a clockwise direction for an unlatching operation or in a counterclockwise direction to engage a child security lock which is also explained in detail below.
Handle mechanism 10 further comprises an unlatching lever 40 that pivots on the lower end of pivot pin 18 below the lower pivot gusset 16 . Unlatching lever 40 has an L-shaped slot 42 and an attachment hole 44 for attaching lever 40 to a door latch (not shown) by a control rod or other suitable linkage (not shown). Unlatching lever 40 is pivoted from the neutral position shown in FIG. 1 clockwise to an unlatching position via slot 42 to unlatch a conventional door latch in a well known manner as explained below.
Handle mechanism 10 further comprises a child security lever 46 that has a depending drive pin 48 at one end, a depending pivot pin 50 at the opposite end and an upwardly projecting pivot pin 52 midway between its ends. Drive pin 48 extends through a generally radial slot 54 in the lower arm 26 of handle lever 20 and projects into slot 42 of unlatching lever 40 . Pivot pin 50 pivots in a pivot hole 51 of lower arm 26 . Child security lever 46 is thus pivotally mounted on lower arm 26 for movement between a decoupled position and a drive position determined by the opposite ends of slot 54 . When child security lever 46 is in the drive position, drive pin 48 engages an inner end of radial slot 54 and a drive shoulder 56 in the narrow inner end of slot 42 . When child security lever 46 is in the decoupled or lost motion position, drive pin 48 engages an outer end of radial slot 54 and is located in the wide outer end of slot 42 where drive pin 48 bypasses drive shoulder 56 and moves in slot 42 without driving unlatching lever 40 .
Handle mechanism 10 includes an over center coil spring 58 that has one end attached to tab 53 of child security lever 46 and the other end attached to lower arm 26 and operates in a well-known manner so that drive pin 48 is biased against one or the other ends of the slot 54 of arm 26 .
A bypass lever 60 pivots on pivot pin 52 of child security lever 46 . A coil return spring 62 is on top of bypass lever 60 around pivot pin 52 . One end of spring 62 engages bypass lever 60 and the opposite end of spring 62 fits in a slot of pivot pin 52 so that bypass lever 60 is spring biased clockwise as viewed in FIG. 1 against an elevated stop 64 of child security lever 46 .
Handle mechanism 10 includes a locking lever 66 that pivots on a horizontal pivot 67 projecting from the backside of housing 12 . Locking lever 66 is shaped like a bell crank lever and has a button handle 68 at an end of one leg that projects through a window 70 of the housing 12 so that the locking lever 66 is operated from the front of housing 12 . Locking lever 66 has a flanged hole 69 midway in the other leg for attaching lever 66 to a door latch (not shown) by a control rod or other suitable linkage (not shown). Unlocking lever 66 is pivoted from the locked position shown in FIG. 1 clockwise to an unlocked position using button handle 68 to unlock the door latch (not shown) as explained below.
Locking lever 66 also controls a push rod 71 that has an end portion 72 that slides in a bracket 73 that is attached to the back side of housing 12 . The opposite end of push rod 71 is secured in an attachment hole 74 of locking lever 66 so that the end portion 72 of push rod 71 translates longitudinally in a generally horizontal direction when locking lever 66 is pivoted on horizontal pivot 67 that is generally perpendicular to the end portion 72 . End portion 72 thus translates between a locked position corresponding to the locked position of locking lever 66 and an unlocked position corresponding to the unlocked position of locking lever 66 . End portion 72 engages and pivots bypass lever 60 under certain conditions as explained below.
The Normal Unlatching Operation
Referring now to FIGS. 2, 3 , 4 and 5 , the normal unlatching operation of handle mechanism 10 is as follows. FIG. 2 is a front perspective view of the handle mechanism 10 and FIG. 3 is a rear perspective view showing the handle mechanism 10 with the parts in a latched and unlocked condition with the child security lock disengaged. FIGS. 4 and 5 show the handle mechanism 10 with the parts in an unlatched and unlocked condition with the child security lock disengaged.
Handle mechanism 10 unlatches a conventional door latch (not shown) in well-known manner simply by pulling the end of handle 22 outwardly, which pivots the handle 22 of handle lever 20 outwardly from the flush neutral position (latched position) shown in FIG. 2 in a clockwise direction to the extended angular position (unlatched position) shown in FIG. 4 . This pivots upper and lower arms 24 and 26 of handle lever 20 from the latched position shown in FIG. 3 in a clockwise direction to the unlatched position shown in FIG. 5 . As upper arm 24 pivots, it moves spring end 30 away from housing 12 and tightens the coils of coil spring 28 in the clockwise direction. (This stores energy in coil spring 28 for returning handle lever 20 to the latched or neutral position shown in FIGS. 2 and 3 when handle 22 is released.) As lower arm 26 pivots, it drives unlatching lever 40 clockwise to the unlatching position via drive pin 48 of child security lever 46 which engages drive shoulder 56 of unlatching lever 40 . When unlatching lever 40 pivots clockwise to the unlatching position, the door latch (not shown) is unlatched by a control rod or other suitable linkage (not shown) secured to unlatching lever 40 . Handle 22 is then released and handle lever 20 is returned to the latched or neutral position shown in FIGS. 2 and 3 by coil spring 28 .
It should be noted that end portion 72 of push rod 71 engages bypass lever 60 pivoting bypass lever 60 counterclockwise on child security lever 46 as child security lever 46 moves clockwise with lower arm 26 during the unlatching operation. This feature allows drive pin 48 to remain in the inner end of slot 54 where drive pin 48 engages drive shoulder 56 of unlatching lever 40 .
Normal Unlatching Operation with Locked Handle Mechanism
FIG. 6 is a rear perspective view showing handle mechanism 10 with the parts in an unlatched position when the handle mechanism is locked and the child security lock is disengaged. Referring now to FIGS. 2, 3 and 6 , handle mechanism 10 is locked simply by moving button handle 68 down from the unlocked position shown in FIGS. 2 and 3 to the locked position shown in FIG. 6 . This rotates locking lever 66 counterclockwise from the unlocked position shown in FIG. 3 to the locked position shown in FIG. 6 . As locking lever 66 is pivoted to the locked position shown in FIG. 6, a control rod or other linkage (not shown) attached to flanged hole 69 is moved to lock a conventional door latch (not shown) in a well-known manner. As locking lever 66 is pivoted to the locked position shown in FIG. 6, locking lever 66 also withdraws end portion 72 of push rod 71 , translating push rod 71 to the right away from bypass lever 60 , i.e., from the position shown in FIG. 3 to the position shown in FIG. 6 .
The unlatching operation is still performed by pivoting handle 22 outwardly in a clockwise direction as described above and as shown in FIG. 4 . However, the unlatching operation is not effective at the door latch (not shown) because the door latch has been locked by locking lever 66 . It should be noted in connection with FIG. 6 that the bypass lever 60 is not effected in this case as handle lever 20 pivots clockwise from the latched position shown in FIGS. 2 and 3 to the unlatched position shown in FIG. 6 because portion 72 has been withdrawn by locking lever 66 .
Operation with Child Security Lock Engaged
The child security lock is engaged by pushing the end of handle 22 inwardly from the flush position shown in FIG. 2 to the child security lock engage position shown in FIG. 7 . This rotates handle lever 20 counterclockwise to the position shown in FIGS. 7 and 8. FIG. 7 is a front perspective view of handle mechanism 10 and FIG. 8 is a rear perspective view of handle mechanism 10 showing the parts in their respective positions when the child security lock is engaged and the locking lever 66 is in the locked position.
As lower arm 26 rotates counterclockwise to the child security position shown in FIG. 8, it moves spring end 34 away from housing 12 and tightens the coils of coil spring 28 in the counterclockwise direction. (This stores energy in coil spring 28 for returning handle lever 20 to the neutral or latched position shown in FIG. 2 when handle 22 is released).
As lower arm 26 rotates counterclockwise to the child security position shown in FIG. 8, cam 17 of housing 12 engages child security lever 46 , pivoting child security lever 46 counterclockwise about pivot pin 50 against the action of over center spring 58 . This shifts drive pin 48 to the outer end of slot 54 where drive pin 48 is now biased by the over center spring 58 . Drive pin 48 also shifts outwardly out of engagement with drive shoulder 56 and into the wider portion of slot 42 in unlatching lever 40 .
After the child security lock is engaged, handle 22 is released and the handle lever 20 is pivoted clockwise and returned to the neutral position where spring end 34 engages housing 12 (not shown). (The neutral position of arms 24 and 26 are about 10 ° clockwise from the position shown in FIG. 8 ).
The unlatching operation is now ineffective at the handle mechanism 10 . When handle lever 20 is pivoted clockwise from the neutral position to the unlatched position shown in FIGS. 4 and 5, the drive pin 48 simply moves in slot 42 without imparting any motion to unlatching lever 40 . Hence the door latch (not shown) that is connected to unlatching lever 40 by a control rod or other linkage (not shown) is not unlatched.
The child security lock can be engaged after an automotive door is closed, latched and locked as demonstrated above. However, the child security lock can also be engaged when the locking lever 66 is in the unlocked position shown in FIGS. 2 and 3 before or after the vehicle door is closed. The child security lock is still engaged by pushing the end of handle 22 inwardly to the child security lock position shown in FIG. 7 and the parts move to the same position except that the locking lever 66 and push rod are in the unlocked position as shown in FIG. 9 . Thus when handle 22 is released, bypass lever 60 engages the end portion 72 of rod 71 tangentially as child security lever 50 pivots clockwise about 100 with lower arm 26 to the latch position (not shown). Drive pin 48 is still shifted to and biased against the outer end of slot 54 by over center spring 58 and also shifted outwardly out of engagement with drive shoulder 56 and into the wider portion of slot 42 in unlatching lever 40 so that the unlatching operation is not effective after the child security lock is engaged.
Disengagement of the Child Security Lock
The child security lock is disengaged by simultaneous operation of handle lever 20 and locking lever 66 in a two-handed operation. Basically, handle lever 20 is moved to and held in the unlatching position with one hand while the locking lever 66 is cycled by the other hand.
The child security lock can be disengaged when the locking lever 66 is in the locked position shown in FIGS. 7 and 8 or in the unlocked position shown in FIG. 9 and after the handle lever returns to the latched or neutral position (not shown).
Referring first to FIGS. 10 through 14, the child security lock is disengaged when locking lever 66 is in the unlocked position as follows. First handle lever 20 is pivoted clockwise from the latched neutral position (not shown) to the unlatch position shown in FIG. 10 . As lower arm 26 pivots clockwise, drive pin 48 is held against the outer end of slot 54 by over center spring 58 and moves to the opposite outer end of the wide outer part of slot 42 in unlatching lever 40 as shown in FIG. 10 . Child security lever 46 thus pivots with lower arm 26 remaining stationary with respect to lower arm 26 . However, bypass lever 60 is held by the end portion 72 of rod 71 so that bypass lever 60 pivots counterclockwise on child security lever 46 away from stop 64 as child security lever 46 pivots clockwise to the position shown in FIG. 10 .
The handle lever 20 is held in the unlatching position shown in FIG. 10 while the locking lever 66 is pivoted clockwise to the locked position shown in FIG. 11 by pushing button handle 68 down. This withdraws rod 71 , i.e., moves rod 71 to the right as viewed in FIG. 10 . The withdrawing rod 71 releases bypass lever 60 which then pivots clockwise under the action of spring 62 into driving engagement with child security lever 46 and into the travel path of the end portion 72 of rod 71 as shown in FIG. 11 .
Locking lever 66 is then pivoted back to the unlocked position by pushing button handle 68 up while handle lever 20 is kept in the unlatching position. This projects rod end portion 72 forward, i.e., translates rod end portion 72 to the left from the position shown in FIG. 11 to the position shown in FIG. 12 . Rod end portion 72 engages bypass lever 60 driving bypass lever 60 to the left, which pivots child security lever 46 clockwise about pivot 50 which moves drive pin 48 from the outer end of slot 54 toward the inner end of slot 54 enough so that drive pin 48 is biased toward the inner end of slot 34 by over center spring 58 . Drive pin 48 is also moved radially inwardly toward the narrow inner portion of slot 42 and the drive shoulder 56 of unlatching lever 40 .
Locking lever 66 is then pivoted back to the locked position by pushing button handle 68 down while handle lever 20 is still held in the unlatching position as shown in FIG. 13 . This withdraws rod 71 to the right as viewed in FIG. 13, that is, away from bypass lever 60 .
After locking lever 66 is cycled from unlock to lock to unlock to lock, handle lever 20 is released so that coil spring 28 returns handle lever 20 to the neutral or latched position shown in FIG. 14 . As lower arm 26 of handle lever pivots counterclockwise from the unlatched position shown in FIG. 13 to the latched position shown in FIG. 14, drive pin 48 is biased inwardly against the inner end of slot 54 and into engagement with drive shoulder 56 in the narrow inner end of slot 42 by over center spring 58 . The handle mechanism 10 is now latched and locked with the child security lock disengaged. The door latch (not shown) operated by the handle mechanism 10 can now be unlocked by pivoting the button handle 68 up to the unlocked position shown in FIGS. 2 and 3 and then unlatched by pulling the end of handle 22 outwardly as shown in FIGS. 4 and 5.
The child security lock can also be disengaged when the locking lever 66 is in the locked position shown in FIGS. 7 and 8 and the handle lever 20 returns to the neutral or latched position (not shown).
Disengagement of the child security lock is still a two-handed operation. However, the first cycling step of the locking lever 66 is eliminated. The handle lever 20 is still pivoted outwardly and held in the unlatching position. However, the locking lever 66 need not be moved to the locked position shown in FIG. 11 because it is already in the locked position. Hence, the child security lock is disengaged by moving the handle lever 20 to the unlatched position shown in FIG. 11 and cycling the locking lever from the locked position of FIG. 11 to the unlocked position of FIG. 12 back to the locked position of FIG. 13 while the handle lever 20 is held in the unlatched position and then releasing the handle lever 20 so that it returns to the neutral or latched position shown in FIG. 14 . As indicated above, the handle mechanism 10 is now latched and locked with the child security lock disengaged. The door latch (not shown) operated by the handle mechanism 10 can now be unlocked by pivoting the button handle 68 up to the unlocked position shown in FIGS. 2 and 3 and then unlatched by pulling the end of handle 22 outwardly as shown in FIGS. 4 and 5.
Obviously, many modifications and variations of the present invention in light of the above teachings may be made. It is, therefore, to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A handle mechanism for operating a vehicle door latch has a handle lever for operating the latching mechanism of a vehicle door latch and a button handle for operating the locking mechanism of the vehicle door latch. The handle mechanism includes a child security lock that disables the handle mechanism so that it cannot unlatch the vehicle door latch. The child security lock is engaged by the handle lever and disengaged by manipulating the handle lever and the button handle in a predetermined sequence.
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INTRODUCTION
This invention relates to seats for children and more particularly comprises a new and improved booster seat which will also function as a high chair.
A number of improvements have been made in the booster seat art in recent years. While the early booster seats had a fixed seat and therefore were not adjustable, and they were designed only for use as a booster seat, more recently improvements have been made in the field which have made the seats adjustable so that they may accommodate very small as well as larger children, and they have been made more versatile by providing them with trays which enable the booster seats to function as high chairs. U.S. Pat. No. 4,854,638 shows such a booster seat wherein the back rest and seat panel may be moved back and forth, and up and down respectively, and the assembly includes a detachable tray. Another booster seat found in the prior art has an invertible seat panel which allows the seating surface to be raised or lowered depending upon which seating surface is utilized. That arrangement is shown in U.S. Pat. No. 4,586,747. Other prior art patents that show children's seats that are collapsible such as U.S. Pat. Nos. 1,739,366 and 4,603,903, while other adjustable child's seats are shown in U.S. Des. Pat. Nos. 330,842 and 314,674.
The principle object of the present invention is to provide a combination booster seat and high chair which is both collapsible and adjustable.
Another important object of the present invention is to provide a collapsible combination booster seat and high chair which when collapsed for toting or storage is a compact package without any loose parts.
Another object of the present invention is to provide a combination booster seat and high chair that is relatively inexpensive to manufacture and which therefore may be sold for a modest price while providing maximum convenience and versatility to its owner.
To accomplish these and other objects, the combination booster seat and high chair of the present invention is made up of five major parts, namely, a back member, a pair of arm panels, a seat panel and a tray. The arm panels are pivotally connected to the back member and are movable between an operative position wherein they extend forwardly generally perpendicular to the plane of the back member and a collapsed position wherein the arm panels are coplanar with one another closely adjacent and parallel to the plane of the back member. The seat panel is detachable from the back member and arm panels and is pivotally mounted on the back panel so that it may be raised to a perpendicular position inside the folded arm panels and in front of the back member. The tray is removable from the arm panels and when the combination booster seat and high chair is collapsed, the tray may be placed between the back member and arm panels adjacent the seat panel. The height of the seat may be adjusted by inverting it on the arm panels and back member, and the tray may be adjusted by releasably locking it in one of two positions on the arm panels. A conventional strap arrangement may be provided to hold the child in the seat, and additional straps may be used to secure the seat to a chair on which it is placed.
These and other objects and features of the present invention will be better understood and appreciated from the following detailed description of the preferred embodiment thereof, shown in the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the booster seat illustrating a preferred embodiment of this invention;
FIG. 2 is a side elevational view of the booster seat of FIG. 1;
FIG. 3 is a top plan view of the booster seat illustrating the tray in multiple positions;
FIG. 4 is a cross-sectional view taken along section line 4--4 of FIG. 3 illustrating the seat panel in alternate positions that afford the ability to select the desired height of the seating surface;
FIG. 5 is a cross-sectional plan view taken along section line 5--5 of FIG. 4 illustrating the manner in which the seat panel and the arms are assembled;
FIG. 6 is a cross-sectional side elevational view taken along section line 6--6 of FIG. 3;
FIG. 7 is a fragmentary cross-sectional view taken along section line 7--7 of FIG. 4 illustrating the seat panel locking mechanism and the attachment of the tray to an arm;
FIG. 8 is an enlarged fragmentary cross-sectional plan view taken along section line 8--8 of FIG. 7 illustrating the guiding and locking mechanism for attaching the tray to an arm and showing the tray latch in the locked and unlocked positions;
FIG. 9 is a fragmentary cross-sectional view taken along section line 9--9 of FIG. 7 illustrating the seat latch in the locked and unlocked positions;
FIG. 10 is a perspective view of the booster seat in the stowed configuration; and
FIG. 11 is a side elevational view of the booster seat in the stowed configuration.
DETAILED DESCRIPTION
A preferred embodiment of the booster seat in an operative configuration is generally indicated at 20 in FIG. 1. The booster seat 20 is comprised of a back member 22, two arms 24 and 26 pivotally connected to side edges 25 and 27 of the back member 22, a reversible seat panel 28, and a multi-position, detachably connected tray 30.
The preferred embodiment of the booster seat in a stowed configuration is shown in FIGS. 10 and 11. The stowed configuration is achieved by dismantling the booster seat whereby the tray is detached from the arms 24 and 26, the seat panel 28 may then be unlocked from the arms 24 and 26 and pivoted within the back member 22 to a generally vertical position, the arms 24 and 26 are then pivotally rotated toward each other and aligned to each other in positions generally parallel to the vertical seat panel 28, and lastly the detached tray 30 is finally placed between the seat panel 28 and the rear wall 34 of the back member 22. The tray 30 is detached from the booster seat by releasing two tray latches 36 and 38, located on each side of the tray 30, and sliding the tray 30 forwardly and away from the back member 22 until it is free from the arms 24 and 26. The seat panel 28 is detached from arms 24 and 26 by depressing two seat release buttons 40 and 42 located on the arms 24 and 26, which unlock seat latches shown at 94 in FIGS. 7 and 9 and hereinafter described, and pivoting the arms 24 and 26 outwardly and away from the seat panel 28 as shown in FIG. 5.
The back member 22 is a one piece structure molded of a plastic material, such as a colored polypropylene copolymer, in a manner generally known in the art. The other major parts of this booster seat 20 may similarly be molded of this same material in the same or different colors. As shown in FIGS. 1 and 10, the arms 24 and 26 are pivotally connected to hinge flanges 44, 46, 48 and 50 which protrude forwardly and away from the side edges 25 and 27 of the back member 22. Each of the hinge flanges 44-50 contains an opening 52, as shown in FIGS. 7 and 8, into which arm pivots 54, provided on the rear top and bottom of the arms 24 and 26, extend to form a hinged mechanism. Referring to FIG. 8, each of the hinge flanges 44-50 is formed with a ramp 56, which slopes from the front edge 58 of a hinge flange 44-50 toward the opening 52, and angled guide walls 60 and 62, which converge toward each other from the front edge 58 toward the opening 52. The assembly of the side arms 24 and 26 to the back member 22 is facilitated by virtue of the guiding action of the ramps 56 and converging walls 60 and 62 acting on the arm pivots 54.
Referring to FIGS. 5 and 6, support channels 64 and 66 are formed in the lower portion of the back member 22, which slidably engage two rear lugs 68 and 70 provided on the seat panel 28. The channels 64 and 66 are formed by two opposed walls 65, as shown in FIGS. 2 and 6, which converge toward each other from the front of the back member 22 toward the rear wall 34. Each wall 65 is formed with a diverging radius 67 at the entrance to the channels 64 and 66 to facilitate the assembly of the seat panel 28 to the back member 22 by providing a guiding action to the rear lugs 68 and 70 during assembly. The channels 64 and 66 act as connecting members and support the rear portion of seat panel 28 when in the operative position for supporting a child and retain the rear portion of seat panel 28 when it is pivoted to a vertical position in the stowed configuration of the booster seat 20.
A child is physically supported in the back member 22, by the upper portion 23 of the rear wall 34 and the side edges 25 and 27, located above the seat panel 28. The upper portion of the seat member 22 may be formed in various shapes and contours to best provide for the comfort and safety of a child.
The seat panel 28 is a two piece structure, comprised of a seat bottom 72 and seat top 74, molded of a plastic material and with the two pieces joined together in a manner generally known in the art. Referring to FIGS. 6 and 9, the seat bottom 72 is molded with connecting members in the form of two rear lugs 68 and 70 and two forward lugs 76 and 78. As shown in FIGS. 6 and 10, radial ears 79 are formed around the forward lugs 76 and 78 to improve the structural integrity of the seat panel 28. The seat top 74 is of greater height than the seat bottom 72 as measured from a horizontal mounting plane established by the lugs 68, 70, 76 and 78. The seat bottom 72 and seat top 74 each provide a seating surface 84 upon which to support an occupant. It is preferred that each seating surface 84 be formed with a textured surface to increase the friction between the occupant and the seat panel 28, and thereby decrease the possibility of a child slipping off the seat panel 28.
The seat panel 28 may be selectively positioned to adjust the seat height to accommodate growing children. Referring to FIGS. 4 and 6, this is achieved by the horizontal mounting plane 80 which is offset from a central horizontal plane 82, which is established at the geometric center between the opposed seating surfaces 84. This allows the seating surface 84 to effectively be lowered or raised simply by inverting the seat panel 28.
The arms 24 and 26, which are mirror images of each other, are two piece structures, comprised of outer arms 86 and 88 and inner arms 90 and 92, molded of a plastic material and with the two pieces joined together in a manner generally known in the art. Referring to FIGS. 7 and 9, the outer arms 86 and 88 and inner arms 90 and 92 support and retain seat latches 94 within each of the arms 24 and 26, which provide a locking mechanism for the booster seat. The outer arms 86 and 88 contain circular openings 96 formed by a tubular support wall 126 that extends into the arms 24 and 26 along the perimeter of the openings 96. The openings 96 support and guide the seat release buttons 40 and 42 within the arms 24 and 26. The inner arms 90 and 92 contain keyhole openings 98 formed with an upper portion 100, a lower portion 102, and a support wall 110 that extends into the arms 24 and 26 along the perimeter of the openings 98. The keyhole openings 98 act as connecting members to support and retain the forward lugs 76 and 78 of the seat panel 28 within the arms 24 and 26 when the booster seat 20 is in the operative configuration of FIG. 1. Children are prevented from injuring their fingers and hands in the upper portion 100 of the keyhole 98, which is covered by the seat panel 28 when positioned in the upper height, and by the ears 79 when the seat panel 28 is inverted to the lower height, as shown in FIG. 2.
A stable and rigid booster seat 20 is achieved with a connecting mechanism that engages the seat panel 28 to the back member 22, and then locks the seat panel 28 to the arms 24 and 26. Referring to FIG. 5, the rear lugs 68 and 70 are first slidably engaged into the support channels 64 and 66 of the back member 22. Referring to FIGS. 6 and 9, the seat panel 28 is then connected to the arms 24 and 26 by inserting the forward lugs 76 and 78 into the upper portion 100 of the keyhole openings 98 and lowering the front of the seat panel 28 to engage the forward lugs 76 and 78 in the lower portion 102 of the keyhole openings 98. The forward lugs 76 and 78 are formed with a minor diameter shaft 104 and a major diameter tip 106. The shaft 104 and tip 106 are sized to ensure that the forward lugs 76 and 78 may only be installed into and removed from the arms 24 and 26 through the upper portion 100 of the keyhole openings 98, but may then be locked and supported in the lower portion 102. The size differential between the shaft 104 and the tip 106 creates a circumferential lip 108 to engage the keyhole wall 110, and prevent the arms 24 and 26 from being pivoted away from the forward lugs 76 and 78, when the seat panel 28 is in the locked position.
With the booster seat 20 in the functional configuration, the seat panel 28 is prevented from being raised from the locked position by an interference created between the seat latches 94 and the forward lugs 76 and 78. Referring to FIGS. 7 and 9, the seat latches 94 are formed with a locking member 112 located at one end of a latch lever 114, and a seat release button 40 attached to the opposite end of the latch lever 114 by an integral flexible strap 116. It should be apparent that the seat release button 40 may be provided as a part separate from the seat latch 94, although this is not preferred because of the additional expense associated with procurement, inventory and assembly, and the likelihood that the buttons would be lost. In the locked configuration, the locking member 112 aligns with and obstructs the upper opening 100 of the keyhole opening 98. The seat latches 94 are positively locked into position by a seat latch spring 118 which is located and retained in the arms 24 and 26 by a spring post 120, and a recess 121 formed in the rear of the locking member 112. The seat latch spring 118, which is a compression type spring, maintains the seat latch 94 in its locked position by exerting a force between the outer arms 86 and 88 and the locking member 112. This force rotates the latch lever 114 on two seat latch pivots 122, which are positioned opposite each other on the latch lever 114 between the locking member 112 and release button 40, and are supported by pivot supports 124. The seat latches 94 are prevented from over-rotating into the upper opening 100 by the opening support wall 126, which engages and positions the latch lever 114 in a generally vertical position, with the locking member 112 located above the tip 106. As shown in FIGS. 7 and 9, an angled, radially shaped detent 127 is formed in the bottom of the locking member 112 to engage the tip 106. The locking capability of the seat latch 94 is enhanced by the increased contact area between the locking member 112 and the tip 106 provided by the radial shape of the detent 127, which conforms with the radius of the tip 106. The locking capability is further enhanced by the angle of the detent 127, which positively engages the lip 108 should the seat panel 28 be raised without first unlocking the seat latch 94, thereby drawing the locking member 112 toward the upper opening 100 and maintaining it over the forward lugs 76 and 78.
The procedure for unlocking the seat panel 28 from the arms 24 and 26, is initiated by depressing each release button 40 and 42. This force is transmitted to the end of the latch lever 114 opposite the locking member 112 through the button pivots 128, as shown in FIGS. 7 and 9, which are positioned opposite each other on the circumference of the buttons 40 and 42, and seated on two button pivot supports 129 located on that end of the latch lever 114. The locking member 112 is rotated around the seat latch pivots 122, and out of the upper opening 100 of the keyhole opening 98. The button pivots 128 prevent the seat release buttons 40 and 42 from binding on the opening support wall 126 during this unlocking operation by allowing the relative angle between the buttons 40 and 42 and the latch lever 114 to continually change during the unlocking sequence. Once the locking members 112 have been rotated clear of the upper openings 100, the seat panel 28 may be raised to align the forward lugs 76 and 78 with the upper openings 100. Referring to FIG. 5, the arms 24 and 26 may then be pivoted away from the seat panel 28 and each other until the forward lugs 76 and 78 are free of the key hole openings 98.
Once the seat panel 28 is unlocked from the arms 24 and 26, it may then be either pivoted to the generally vertical position for stowage, as shown in FIGS. 10 and 11, or inverted to selectively adjust the height of the seating surface 84. The seat panel 28 may be detached from the back member 22 by sliding the rear lugs 68 and 70 out from the support channels 64 and 66 to the arm recesses 130 and 132 formed in the arms 24 and 26. The arm recesses 130 and 132 are formed by two generally parallel and opposed walls 131, as shown in FIGS. 6 and 7, and a radius 133 formed on each wall 131 at the entrance to the recesses 130 and 132. When the rear seat lugs 68 and 70 have been disposed in the arm recesses 130 and 132, the arms 24 and 26 may be fully pivoted away from each other allowing the seat panel 28 to be removed.
The tray 30 is a one piece structure molded of a plastic material in a manner generally known in the art. As shown in FIGS. 8 and 9, the tray 30 is formed with an inside guide lug 134, an outside forward guide lug 136, and an outside rear guide lug 138 located on each side of the tray 30. The tray 30 is detachably connected to the arms 24 and 26, whereby the outer guide lugs 136 and 138 are slid into and engage the tray guide slots 140 and 142 provided in the upper portions of the arms 24 and 26. The outside guide lugs 136 and 138 are L-shaped, as shown in FIG. 4, to prohibit the tray 30 from being lifted in the vertical direction and off the arms 24 and 26.
Referring to FIG. 3, the tray 30 is locked into one of two available positions and prevented from sliding therefrom by the tray latches 36 and 38. As shown in FIG. 8, each of the latches 36 and 38 is formed with a catch body 144 connected to a latch anchor 146 by an integral flexible hinge 148. The tray latches 36 and 38 are detachably connected to the tray 30 with a pin 150 and a fastener 152. The catch body 144 is formed with a catch lug 154 which engages either of the two detents 156 located within the tray guide slots 140 and 142, and locks the tray 30 in the desired position. While the preferred embodiment shows two detents 156 formed within each guide slot 140 and 142, the number of detents 156 may be varied to increase or decrease the available lock positions for the tray 30. The tray 30 is formed with a side wall 158 around the entire perimeter to provide a surface which will retain, among other things, eating utensils, spilled liquids, and children's toys. Further, to improve the comfort of the booster seat 20, while occupied by a child, the tray 30 is formed with two radially shaped rear edges 160 and 162, which allow the child to rest his or her arms thereon.
The safety of the booster seat 20 is enhanced by a non-slip bottom created by a plurality of widely available rubber buttons 164, which are connected to the bottom of the back member 22, and the arms 24 and 26, as shown in FIGS. 2 and 6. Nylon webbed or similar type straps (not shown), which are widely known and commercially available, are provided to secure the booster seat 20 on a chair or other base, and to secure a child in the booster seat 20. As shown in FIGS. 1, 6 and 10, openings 166 are formed in each of the arms 24 and 26, which are used in configuration with the straps (not shown) to secure the booster seat 20 to a chair or other base. Referring to FIGS. 4 and 5, similar openings are also provided in the back member 22 to secure the booster seat 20 or a child in the seat 20.
The portability of the booster seat 20 is enhanced by an easy grip handle 168 molded into the upper portion of the back member 22.
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A combination booster seat and high chair having a back member and a pair of arm panels pivotally connected to the sides of the back member. The arms move between an operative position wherein they are disposed essentially perpendicular to and extending forward of the back member and an inoperative position wherein they lie in a plane closely adjacent to and parallel with the back member. A seat is detachably connected to both the back member and the arms panels and may be pivoted to a vertical position on the back member when the unit is in the inoperative position so that the seat panel lies between the back member and the side panels. A tray is detachably connected to the side panels and may be removed when the unit is in the inoperative position and stored adjacent the seat between the back member and the arm panels. The height of the seat may be varied by inverting it in the operative position, and the tray may be adjusted toward and away from the back member.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 09/410,982, filed Oct. 1, 1999 which is a continuation-in-part of U.S. Ser. No. 09/307,195 filed on May 7, 1999 which is a continuation application of International Application No. PCT/US98/08348, filed on Apr. 24, 1998 and designating the United States which is a continuation-in-part application of U.S. Ser. No. 08/845,333 filed on Apr. 25, 1997, the entire teachings of the above applications being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Numerous devices have been used to position tissue at a surgical site to aid in the performing of surgical procedures. Retractors, for example, have been used to hold an artery in position during operations adjacent to the heart to prevent movement of the artery. This serves to minimize the risk of injury to the artery and adjacent tissue and can facilitate the desired anastomosis.
[0003] A recently developed procedure, referred to as the minimally invasive direct coronary artery bypass procedure, has been used to graft onto a coronary artery without cardiopulmonary bypass. This procedure involves the grafting of the left internal mammary artery (LIMA) onto the left anterior descending (LAD) or other artery. As this procedure does not require the use of a heart lung machine to oxygenate and pump blood, the morbidity and mortality associated with this procedure is substantially lower than previous bypass techniques. A problem associated with the minimally invasive procedure, however, is that while the heart continues to pump during the procedure, the motion of the heart can interfere with the surgeon's task of attaching the LIMA to the LAD. There is also a need to stop blood flow in the area of the graft to maintain a clear field of view and provide precise suture placement.
[0004] Two basic strategies have been employed to address the problem of operating on a moving site, one being the use of pharmacological agents to limit heart motion, and the other being mechanical, such as a two prong retractor that is pushed down against the heart on both sides of the artery, or alternatively, upward traction away from the moving heart by traction tape or suture thread. Both of these options, however, have problems associated with them. Both options are susceptible to some movement of the vessel grafting site. The use of pharmacological agents is undesirable and impairs circulatory function. Traction by compression of the heart against the spine does serve to immobilize the site but can compromise the ability of the heart to maintain circulation and result in hypotension. Upward traction can involve circumferential compression of the artery to occlude the artery and prevent blood flow, however upward traction that is sufficient to immobilize the site can cause injury, stenosis or occlusion of the vessel.
[0005] There is a continuing need however for improvement in devices and methods for retaining tissue at surgical sites to further reduce the risks associated with surgical procedures where the devices and methods are inexpensive; safe and reliable.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a surgical retractor for immobilizing tissue at a surgical site and to a method of using the retractor during a surgical procedure. A preferred embodiment of the retractor includes a retaining element having an aperture that exposes the surgical site and a holder that is used to position tissue at the surgical site relative to the retaining element. A handle can be attached to or fabricated with the retaining element or platform so that the user can manipulate the position of the retractor as needed.
[0007] In a preferred embodiment of the invention a connector such as elastic tape or thread is used to position tissue at the surgical site within the retractor aperture and to prevent movement of the tissue during the procedure. The connecting cord, thread or tape also aids in the compression of the artery in a grafting procedure to occlude flow on one or both sides of the surgical site. The cord is attached to the holder on the retaining element. A preferred embodiment of the holder can be a plurality of slits or openings positioned on both sides of the retractor that receive and frictionally secure the cord on both sides of the aperture. In another preferred embodiment a mechanical fastener is used to grip both sides of the cord. The fastener can be a spring mounted valve, for example, that allows the user to adjust the tension in the cord.
[0008] A preferred embodiment of the invention comprises a retaining element or base having two sections that can be separated after the procedure is complete to permit removal of the retractor from under the grafted artery. Another preferred embodiment uses a side opening in the platform of the retractor that extends to the aperture so that the grafted artery slips through the side opening during removal. During minimally invasive direct coronary artery bypass operations, one or more surface sections of the retractor platform can be positioned against the inner surface or posterior aspect of one or both ribs adjacent to the surgical site. Thus, the size and geometry of the platform are selected to utilize the adjoining ribs where the upper surface of the platform frictionally engages the inner surface of one or more ribs to hold the retractor in a fixed position. The retractor can be beneficial in any procedure where it is necessary to stabilize a surgical site. For example, the retractor can also be used for grafting onto the diagonal, right or other coronary arteries without altering the heart's pumping function.
[0009] The coronary arteries are about 1-2 mm in diameter, and the pumping heart can move these arteries over distances of several millimeters during each heartbeat. As the movement of even 1 or 2 millimeters can result in a displacement of the grafting site that can substantially interfere with effective anastomosis, it is desirable to restrain movement of the artery at the surgical site in any direction to less than 1 mm. The retractor of the present invention restrains movement in the plane of the base to less than 0.5 mm, and preferably less than 0.2 mm.
[0010] In a preferred embodiment of the invention, the handle or articulating arm that is secured to the platform can be held in position by the user, attached to a frame that is fixed around the operative site or simply clipped to a drape around the site.
[0011] In a preferred embodiment of the invention, the surgical retractor can be optically transmissive or transparent to allow enhanced visibility of the underlying adjacent tissue at the desired surgical site. The aperture of the retractor in accordance with the present invention, varies in size and can range from 1-3 cm in length and 5-15 mm in width.
[0012] In a preferred embodiment, the surgical retractor has raised holder elements disposed in the longitudinal dimension of the retractor, each holder element having a pair of slots that frictionally grip an end of a connector such as an elastic tape or thread which extends through the aperture to attach tissue to the retractor. The surgical retractor further has run off areas on the four corners of the retractor that have a downward slope. These run off areas allow for fluid drainage during the surgical procedure to assist in maintaining the surgical field adjacent to the aperture clear of blood during the anastomosis. The four corners of the base have a gradually thinner cross-section to provide the downward slope.
[0013] In a preferred embodiment, the surgical retractor includes a two-component configuration to allow the retractor to be separated after the surgical procedure is completed to permit removal of the retractor from under the grafted artery. A pair of plastic tabs extend between the two components to securely retain the components together during the procedure and to allow the surgeon to release the components following the procedure by cutting the tabs with a knife.
[0014] In another preferred embodiment, the surgical retractor has slots or grooves on the bottom surface of the retractor to allow the user to place the connector such as elastic tape or thread, either under or over the retractor to position tissue at the surgical site within the retractor aperture and to prevent movement of the tissue during the procedure. When these slots are used the tapes are threaded through the tissue of the heart-wall of the patient and then aligned to be positioned in the desired underlying slots. The surgeon can include additional tissue around the blood vessel as the tapes are tightened so that the blood vessel is compressed by the adjacent tissue rather than being constricted by the tapes. Additionally, the surgeon can position the tapes at a relatively sharp angle of approach. Alternately, a wider angle of approach may be used wherein the tapes are threaded around the outer surface of the retractor so that more tissue is positioned between the tapes and the blood vessel. The route used by the surgeon varies depending on the depth of the desired blood vessel and the surgeon's preferred approach to performing the anastomosis.
[0015] In a preferred embodiment, portions of the bottom surface form a slightly curved surface which extends a slight distance downwardly parallel to the lengthwise dimension of the aperture which assists in retaining the retractor in the desired position on the heart wall of the patient as it continues beating. The bottom surface that surrounds the artery and is in contact with the pericardium can be roughened or abraded to frictionally engage the pericardium around the artery and thereby locally restrict heart motion around the surgical site. There are elevated regions or protrusions such as ridges or nubs, for example, disposed on the bottom surface of the retractor to frictionally engage the pericardium wall around the surgical site.
[0016] When used in a minimally invasive coronary bypass procedure, the retractor is positioned to expose the left anterior descending (LAD) artery grafting site after incision, removal of the rib section and dissection of the left internal mammary artery (LIMA) from the chest wall. A pair of cords, for example, silastic tape (i.e. a silicon elastomer) or suture thread, are passed through the myocardium at two locations flanking the artery grafting site with blunt needles. The four ends of the two cords are connected to the platform holder with sufficient tension to occlude blood flow on both sides of the operative site. The tapes compress the artery against the bottom surface of the platform while they hold the artery grafting site in a fixed position relative to the aperture. The coronary artery is opened longitudinally and the end of the mammary artery is sewn to the graft opening with multiple fine sutures. The cords are released, blood flow is restored and the anastomosis is inspected for hemostatis and other defects and the wound is closed.
[0017] The platform can include tabs or cord retainers that extend into the aperture to provide a surface against which the arteries can be compressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of a surgical retractor in accordance with a preferred embodiment of the invention.
[0019] [0019]FIG. 2 is a perspective view of a surgical site illustrating a surgical procedure.
[0020] [0020]FIG. 3 is a perspective view of a surgical retractor for a grafting procedure in accordance with the invention.
[0021] [0021]FIG. 4 is a bottom perspective view of a surgical retractor in accordance with the invention.
[0022] [0022]FIG. 5 is a cross-sectional view of a surgical retractor during a surgical procedure.
[0023] [0023]FIGS. 6A and 6B are partial cross-sectional views of a holder in accordance with the invention.
[0024] [0024]FIG. 7 is a top view of a two piece retainer in accordance with the invention.,
[0025] [0025]FIG. 8 is a top perspective view of another preferred embodiment of a surgical retractor in accordance with the invention.
[0026] [0026]FIG. 9 is a top perspective view of another preferred embodiment of a surgical retractor in accordance with the invention.
[0027] [0027]FIG. 10 is a schematic diagram illustrating a surgical procedure in accordance with the invention.
[0028] [0028]FIG. 11 is a perspective view of a frame supporting a retractor in accordance with the invention.
[0029] [0029]FIGS. 12A and 12B are enlarged detailed views of a surgical retractor in accordance with the invention.
[0030] [0030]FIG. 13 is an enlarged detailed top view of the preferred embodiment of a surgical retractor illustrating a separated two-section configuration of the retractor.
[0031] [0031]FIG. 14 is an enlarged detailed top view of the preferred embodiment of the surgical retractor shown in FIG. 13.
[0032] [0032]FIG. 15 is an enlarged detailed bottom view of the preferred embodiment of the surgical retractor shown in FIG. 13.
[0033] [0033]FIG. 16 is a perspective view of a preferred embodiment of a surgical retractor in a surgical site illustrating a surgical procedure in accordance with the present invention.
[0034] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] A preferred embodiment of the invention is illustrated in connection with FIG. 1. A retractor 10 includes a retaining element or base 12 having an aperture 16 that is positioned to expose tissue at a surgical site. The base 12 can be made with a metal or a molded plastic material. The retractor 10 can be sterilized after each use, or alternatively, can be disposable after one procedure. A handle 30 or articulating arm can be permanently attached to the base 12 , or as described below in connection with other preferred embodiments, can be detachable.
[0036] A suction tube 32 can be attached to the handle 30 or integrated therein and is used to remove material such as blood from the operative site. In this particular embodiment the tube 32 is connected at one end to a tube 34 from a suction pump and connected at a second end to a port 36 in fluid communication with a channel within tube 28 that extends around the periphery of base 12 . The peripheral tube can have small openings 38 positioned on the sides or top thereof through which fluid such as blood or other debris can be suctioned from the surgical site to maintain a clear field.
[0037] A preferred embodiment of the invention can be used at a surgical site 50 such as the example illustrated in FIG. 2. In this particular procedure for a coronary graft without cardiopulmonary bypass, a section of the 4th costal cartilage or rib 56 is removed to expose a section of the LAD artery 61 .
[0038] A proximal portion of the LIMA 62 is dissected from the chest wall to expose an end 65 to be grafted onto a grafting site 66 on artery 61 . Blood flow in vessel 62 can be occluded with a clamp 64 .
[0039] In this example, a connector such as a pair of cords or silastic tapes 70 , 72 are threaded through myocardium surface 78 under the artery 61 at two locations 74 , 76 on opposite sides of the grafting site 60 . Note that the exposed surface 78 of heart 52 is undergoing substantial movement during the procedure.
[0040] As seen in the reverse perspective view of FIG. 3 in which the retractor 10 has been inserted and positioned during the procedure, the retractor 10 serves to immobilize the grafting site 60 using connecting tapes 70 , 72 which are stretched and attached to a holder mechanism including slots 20 a - 20 d in the peripheral edge of base 12 . As described in greater detail below, the slots 20 A- 20 d can be manually opened or closed using actuators 22 a - 22 d , respectively, to allow the user to adjust the tension in the tapes or threads.
[0041] The aperture 16 extends longitudinally along the axis of artery 61 . The site 60 is preferably located in the plane of the upper surface of base 12 . The tapes 70 , 72 exert a compressive force on the artery 61 which is pressed against a bottom surface 40 as seen in FIG. 4. More particularly, the tapes 70 , 72 extend in a direction that is substantially perpendicular to the artery 61 axis exposed in the aperture 16 . The aperture can have a first pair of lateral sections 18 a and 18 b which are aligned to accommodate the positioning of tape 70 and the aperture can also have a second pair of lateral sections 18 c and 18 d to accommodate the positioning of tape 72 . Alternatively, holes extending through the base 12 that are separated from the aperture can be used. The holes are large enough to provide easy feed through and can be angled towards the bottom center to provide compression of the artery at lower tension of the cord.
[0042] The size of the aperture can be in the range of 1-3 cm in length and 5-15 mm in width. The aperture can be narrower in the center and wider at the opposite ends to accommodate the openings or sections 18 a - 18 d.
[0043] Between each pair of sections 18 a - 18 b and 18 c - 18 d , a sidewall section of the aperture, namely tabs 24 , 26 extend on opposite ends of aperture 16 . The tapes 70 , 72 compress respective portions of artery 61 on opposite sides of site 60 against tabs 26 , 24 . As seen in FIG. 4, those portions 42 , 44 of the bottom surface 40 are in contact with artery 61 and compress it. The bottom surface that surrounds the artery and is in contact with the heart wall can be roughened or abraded to frictionally engage the heart wall around the artery and thereby locally restrict heart motion around the surgical site.
[0044] In a preferred embodiment of the invention opposite ends 82 and 84 can be positioned under adjacent ribs 54 and 58 , respectively. This eliminates any substantial movement of the base 12 while the heart is pumping so that anastomosis 80 of the end 65 onto site 60 can be quickly completed. The opposite ends 82 , 84 can be slightly raised relative to the plane of the remainder of the base 12 to provide a concave structure to enhance the frictional engagement of sections 82 , 84 to ribs 54 , 58 , respectively. The platform has a substantially rectangular shape with each side having a length in the range between 3.5 cm and 6 cm. Thus the surface area of the platform is between 12 cm 2 and 25 cm 2 , preferably between 14 cm 2 and 20 cm 2 . This size fits readily in the incision between the ribs and can be positioned with both ends extending under the 3rd and 5th ribs. This structure exerts little downward force on the heart or upward force on the artery while immobilizing the artery at the surgical site. Also the anterior-posterior compression of the artery avoids trauma to the artery due to circumferential compression. By engaging the ribs, the retractor is self retaining providing for easier use and manipulation.
[0045] As seen in FIG. 5, the tape 76 under the bottom surface 94 of the tab 24 lifts the artery 60 to form an occlusion 86 . This view also shows the optional channel 92 extending around the periphery of base 12 that is used to irrigate or suction around the site.
[0046] The fastening mechanism is illustrated in the partial cross-sectional views of FIGS. 6A and 6B. The closed position 110 is illustrated in FIG. 6A where spring 112 has expanded to move slot 116 in element 115 out of alignment with slot 114 in the outer tube. The cord 72 is displaced and frictionally grasped by the sliding movement of element 115 . The user can manually displace 118 to align slot 114 with slot 116 while compressing spring 112 . In the “open” position 120 , the cord 72 can be easily removed or pulled through to increase tension.
[0047] After the procedure is complete the retractor 10 needs to be removed from the site. In the embodiment of FIG. 1, the base 12 can be formed with two sections or plates 14 a , 14 b . As seen in FIG. 7, these components can be separated at joint 25 to allow removal of the retractor 10 . The two halves 14 a , 14 b can be connected with a frictional tube section 96 .
[0048] In the preferred embodiment illustrated in FIG. 8, the retractor 100 can have a plurality of handle attachment sites 102 , 104 , 106 , 108 so that the user can attach the handle 105 at any site to provide the most convenient access to the aperture and facilitate immobilization of other arteries. The handle can alternatively be positioned between the two cords at an orthogonal angle relative to the aperture axis and extending above the top surface of the base.
[0049] In another preferred embodiment of the invention illustrated in the perspective view of FIG. 9, a retractor 140 has a handle 142 , slots 144 located in the plane of the aperture 160 to secure the cords, end sections 162 , 164 that engage the ribs 54 , 58 , tabs 148 , 150 for compression of both sides of the artery at the site 60 and a side opening 146 so that the retractor can be removed.
[0050] In this embodiment, the LIMA slides out through opening 146 during removal of the retractor after completion of the procedure. This unitary retractor structure 140 can also include various features described previously in connection with the embodiment of FIG. 1 including the attached or integrated suction tube, the detachable handle, the irrigation or suction channel with ports or the mechanically actuated fasteners.
[0051] A preferred method of stabilizing tissue during a coronary bypass procedure 200 is illustrated in the process flow sequence of FIG. 10. A 5-8 cm sized incision is made over the 4th rib and a section of the 4th costal cartilage is removed 202 . The LIMA is dissected from the chest wall 204 and divided distally. After blood flow assessment the LIMA can be temporarily closed with a spring loaded clip.
[0052] A self-retaining wound retractor is used to distract the edges of the incision and a “trap door” incision is made in the pericardium and the cut edge sewn to the skin to pull the pericardial sack and heart anteriorly. The LAD is exposed and a site suitable for anastomosis is selected for grafting 206 . Tapes are inserted in the myocardium with blunt needles approximately 1-2 cm apart 208 and the retractor is inserted 210 with the tapes being pulled through the aperture and positioned in the lateral sections thereof. The tapes are connected to the holder 212 to compress the artery 214 and occlude blood flow on both sides of the grafting site. The tension in the tapes can optionally be adjusted during the procedure to minimize blood loss at the site.
[0053] The retractor is secured 216 at the site by positioning one or both ends under adjoining ribs, or alternatively, attaching the handle or arm to the wound retractor or other implement. The grafting site undergoes less than 0.1 mm of movement in any direction during this example procedure.
[0054] The site is suctioned or irrigated 218 during anastomosis, the grafting site is inspected, the tapes are released from the holders, and the retractor is removed either by sliding the LIMA through a side opening in the retractor or detaching a section of the retractor to accommodate removal of the LIMA from the aperture. After blood flow is restored, the site is inspected and closed 220 .
[0055] Although the use of the retractor has been described in connection with a particular bypass procedure, it can also be used in other procedures such as bypass operations involving the diagonal, right or other coronary artery where movement at the site can interfere with the procedure.
[0056] Alternative embodiments involve opening of the chest and positioning the retractor at any exposed site on the heart wall or surrounding areas to immobilize the operative site. The retractor serves to isolate the site and limits or stops motion at the site due to respiratory movement of the lungs or the pumping motion of the heart.
[0057] In another preferred embodiment, a stabilizer system or frame 240 manufactured by Genzyme Surgical Products is illustrated in FIG. 11 to support a surgical retractor 260 in accordance with the invention.
[0058] The frame 240 used with the invention includes a bar 242 having an arm 244 extending orthogonally from a first end and attached to a second arm 246 with a thumb screw at a second end. Each arm 244 , 246 has a pair of mounting elements 252 , 255 on which a pivot rod 256 can be mounted. This rod 256 can be rotated 360 degrees to any desired position such that mounting arm 245 can oriented relative to the surgical site as needed to position the retractor 260 . Each arm 244 , 246 has a pair of grippers 248 , 250 that engage anatomical features such as neighboring ribs at the site to stabilize the frame 240 .
[0059] The mounting arm 245 supports the handle or support arm 262 with a friction fitting 258 which the user tightens with knob 268 to grip arm 262 at region 266 . The support arm 262 has a knob 264 at one end that can be turned by the user to engage a post 276 shown in FIG. 12A. A ball on the post 276 can be slipped through an opening 265 in the second end of arm 262 and locked into position using knob 264 .
[0060] The post 276 can be pivoted relative to arm 262 by loosening the knob 264 , thus allowing the user to orient the retractor 260 at the site for fine positioning. The post 276 is mounted on a plastic retaining element 270 in this embodiment. The element 270 can be a transparent or opaque molded device that can be separated into two components 272 , 274 as described previously. The two components can be attached by friction fit rods 294 that are inserted into holes in element 272 . Element 270 can be made with a transparent material to enhance visibility at the site.
[0061] Both components have raised holder elements 284 , 286 . Element 284 has a pair of slots 288 , 289 that each frictionally grip an end of a cord which extends through the aperture 278 to attach tissue to the retractor. The second end of each cord is gripped by corresponding slots 290 , 292 in element 286 .
[0062] Tabs or cord retainers 280 , 282 are integrally formed with component 274 and function as described previously. In the detailed partial view of FIG. 12B, the front inclined surface can be formed at a shallower angle such that the top ridge 279 is narrower. This embodiment of cord retainer 281 affords easier insertion of cords into the aperture.
[0063] This embodiment can also be formed with integral suction channels or openings in the top surface of the element 270 . A suction tube can be attached through or with the arm 262 or attached to a suction port on element 270 .
[0064] [0064]FIG. 13 illustrates an enlarged detailed top view of a preferred embodiment of the surgical retractor. A retractor 300 includes a retaining element or base 312 having an aperture 316 that is positioned to expose tissue at a surgical site. The base 312 can be made with metal or a molded plastic material. The retractor can be used on multiple vessels for the same patient, can be sterilized and reused on additional patients as desired, or can be disposed of after each use.
[0065] The size of the aperture 316 can be in the range of 1-3 cm in length and 5-15 mm in width. The aperture 316 can be narrower in the center and wider at the opposite ends to accommodate the opening required for the surgical site. The aperture 316 can have a first pair of lateral sections 320 a and 320 b which are aligned to accommodate the positioning of a first connector such as tape or thread and the aperture can also have a second pair of lateral sections 320 c and 320 d to accommodate the positioning of a second connector such as tape or thread. A connector such as a pair of cords or silastic tapes are threaded through myocardium surface under an artery at two locations on opposite sides of the grafting site.
[0066] Between each pair of sections 320 a - 320 b and 320 c and 320 d , a sidewall section of the aperture, namely tabs 322 , 324 extend on opposite ends of aperture 316 . The aperture can also have longitudinally extending angled sidewalls 325 a , 325 b , that descend at an oblique angle into the aperture. The angled sidewalls 325 a , 325 b , as well as the angled upper surfaces of tabs 322 , 324 aid in providing better access to the surgical site. The oblique angle extends from the plane of the upper surface containing surface regions 327 a , 327 b to the surfaces of sidewalls 325 a , 325 b . The tapes extend through the heart tissue adjacent to the artery and compress respective portions of an artery on opposite sides of site 60 against tabs 322 , 324 as the tapes are tightened by the surgeon.
[0067] The surgical retractor has raised holder or sidewall elements 326 , 328 . Element 326 has a pair of slots 330 , 332 that each frictionally grip an end of a cord which extends through the aperture 316 to attach tissue to the retractor. The second end of each cord is gripped by corresponding slots 334 , 336 in element 328 .
[0068] There are run off areas 338 a - 338 d on the corners of the retractor that have a downward slope. These run off areas allow for fluid drainage during the surgical procedure to assist in maintaining the surgical field adjacent to the aperture 316 clear of blood during the anastomosis. The four corners of the base 312 have a gradually thinner cross-section to provide the downward slope. The top surface of the base 312 can have two substantially planar areas 327 a , 327 b which extend between the angled sidewalls 325 a , 325 b and the corresponding holder elements 326 , 328 which extend in a direction orthogonal to the plane of the upper surface of base 312 . Additionally the upper surface of base 312 has endwalls 329 a , 329 b , 329 c , 329 d at both ends of the aperture. The endwalls 329 a - d combined with raised sidewall elements 326 , 328 define the openings 338 a - d.
[0069] A post 340 is used with the frame 240 shown in FIG. 11 to allow the user to orient the retractor 300 at the site for fine positioning. The post 340 is mounted on the plastic retaining element 342 in this embodiment. Element 342 can be made with a transparent material to enhance visibility of the underlying adjacent tissue at the desired surgical site or can be an opaque molded device. The element 342 can be separated into two components 344 , 346 . The two components 344 , 346 can be attached by fit rods 348 , or similar retaining mechanisms, that are inserted into holes in element 346 . In a preferred embodiment of this invention, a pair of plastic tabs 347 or bridge-type members extend between the two components, 344 and 346 . The plastic tabs 347 can be welded or snapped into place to securely retain the components together during the procedure and to allow the surgeon to release the components following the procedure by cutting the tabs 347 with a knife.
[0070] [0070]FIG. 14 illustrates an enlarged detailed top view of the surgical retractor 300 showing the combined two-component 344 , 346 configuration. The two-component 344 , 346 configuration of the preferred embodiment of the surgical retractor allows the retractor to be separated after the surgical procedure is completed to permit removal of the retractor 300 from under the grafted artery.
[0071] [0071]FIG. 15 illustrates an enlarged detailed view of the bottom surface 360 of the preferred embodiment of the surgical retractor 300 . The portions 362 , 364 of the bottom surface 360 are in contact with an artery and form a slightly curved surface which extends a slight distance downwardly parallel to the lengthwise dimension of the aperture 316 . The addition of the curved bottom surface 360 in combination with the elevated regions 366 , described below, further assist in retaining the retractor in the desired position on the heart wall of the patient as it continues beating. The bottom surface 360 that surrounds the artery and is in contact with the pericardium can be roughened or abraded to frictionally engage the pericardium around the artery and thereby locally restrict heart motion around the surgical site. There are elevated regions 366 or protrusions such as ridges or nubs for example, disposed on the bottom surface 360 of the retractor to frictionally engage the pericardium.
[0072] A preferred embodiment may have slots or grooves 368 a - 368 d as shown in FIG. 15 on the bottom surface 360 of the retractor to allow the user to place the tapes either under or over the retractor for subsequent securement. When these slots are used, the tapes are threaded through the tissue of the heart wall of the patient and then aligned to be positioned in the desired underlying slots. The tapes are then grasped and lifted around the outer surface of the holder elements 326 and 328 and then positioned in the desired slots 330 , 332 , 334 , 336 . This feature allows the surgeon to include additional tissue around the blood vessel as the tapes are tightened so that the blood vessel is compressed by the adjacent tissue rather than being constricted by the tapes. Additionally, this feature allows the surgeon to position the tapes at a relatively sharp angle of approach. The tapes are then threaded through the aperture and into the desired slots. Alternately, a wider angle of approach may be used wherein the tapes are threaded around the outer surface of the retractor so that more tissue may be positioned between the tapes and the blood vessel. The route used by the surgeon will vary depending on the depth of the desired blood vessel and the surgeon's preferred approach to performing the anastomosis.
[0073] [0073]FIG. 16 illustrates a transparent surgical retractor positioned in the surgical site 380 . The retractor 300 has been inserted and positioned during a procedure for a coronary graft without a cardiopulmonary bypass, a section of the 4 th costal cartilage or rib 382 is removed to expose a section of the LAD artery 384 . The retractor 300 serves to immobilize the grafting site 386 and is preferably used in combination with the connecting tapes 388 , 390 which are stretched and attached to a holder mechanism including slots 330 , 332 , 334 , 336 in the peripheral edge of base 312 .
[0074] The aperture 316 extends longitudinally along the axis of the artery 384 . The site 380 is preferably located in the plane of the upper surface of base 312 . The tapes 388 , 390 exert a compressive force on the artery 384 which is pressed against the bottom surface 360 as seen in FIG. 15. More particularly, the tapes 388 , 390 extend in a direction that is substantially perpendicular to the artery 384 exposed in the aperture 316 .
[0075] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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The present invention relates to a surgical retractor that immobilizes tissue at a surgical site. A preferred embodiment of the retractor is used during minimally invasive direct coronary bypass procedures to arrest movement of the grafting site while the heart continues pumping. Tape or thread can be used to connect the artery to the retractor with a holder.
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This is a continuation of application Ser. No. 07/431,009, filed on Nov. 1, 1989 now abandoned.
FIELD OF THE INVENTION
This invention is directed to disposable absorbent articles worn to assist in the collection of bodily discharges, more particularly to sanitary napkins for the collection of menstrual discharges, and even more particularly to sanitary napkins having a laterally extensible backsheet or laterally extensible wings, at least one of which is affixed to the wearer's undergarment.
BACKGROUND OF THE INVENTION
Sanitary napkins and related disposable absorbent articles which collect menstrual discharges and protect against soiling of the wearer's clothing and bedding are well known in the art. These articles typically have a topsheet positioned against the body of the wearer, a backsheet which prevents the escape of bodily discharges from the sanitary napkin and an intermediate core which absorbs bodily discharges.
Sanitary napkins typically also have a means for attaching the sanitary napkin to the wearer's undergarment. For example, pressure sensitive adhesive on the outwardly oriented face of the backsheet has been long used in the art for this purpose. The adhesive on the outwardly oriented face of the backsheet is typically disposed in a rectangular patch or two longitudinally oriented and parallel strips, such as illustrated in U.S. Pat. No. 3,672,371, issued Jun. 27, 1972 to Roeder. As illustrated in the U.S. Pat. No. 3,672,371 patent, the parallel strips may either be continuous or intermittent.
Improvements to such fastening means have also been attempted in the prior art. For example, U.S. Pat. No. 4,445,900, issued May 1, 1984 to Roeder discloses a sanitary napkin having an adhesive pattern in the form of two strips forming an X-shape crossing at the center of the napkin. Yet another attempt at providing an improved adhesion to the undergarment of the wearer is illustrated in U.S. Pat. No. 4,333,466, issued Jun. 8, 1982 to Matthews. This patent discloses adhesive which partially traces the outline of the perimeter of the sanitary napkin with concave outwardly oriented recesses.
The backsheet attachment means of the prior art suffer from the drawback that no allowance is made for the movements, particularly lateral extension, of the undergarment of the wearer. As the undergarment encounters the typical movements of the wearer, the attachment means of the backsheet may not be able to accommodate the stresses and deflections associated with such movements. Consequently, the means for attaching the sanitary napkin to the undergarment is stressed and may result in the sanitary napkin shifting from its intended position or, may, if the exerted forces are great enough, even result in the sanitary napkin becoming detached from the undergarment.
Another development which provides further protection against the soiling of bodily discharges and a means for positioning the sanitary napkin and attaching it to the undergarment is flaps which extend outwardly from each longitudinal edge of the sanitary napkin. Flaps which have been advantageously used with sanitary napkins are shown in U.S. Pat. No. 4,589,876, issued May 20, 1986 to Van Tilburg and U.S. Pat. No. 4,687,478, issued Aug. 18, 1987 to Van Tilburg, which patents are incorporated herein by reference for the purpose of showing particularly preferred executions of flaps used in conjunction with sanitary napkins.
These flaps also typically have adhesive disposed on the outwardly oriented face of the backsheet of the flap. While the specific form of the adhesive varies little, a typical execution is shown in U.S. Pat. No. 4,701,178, issued Oct. 20, 1987 to Glaug et al.
Flaps extending outwardly from the longitudinal edge of the napkin have also suffered from the drawbacks that, unless precisely and properly positioned, the flaps may not move with the undergarment of the wearer, may become detached if the forces exerted by the movements of the undergarment exceed the strength of the adhesive used to affix the flaps to the undergarment, and cannot fully accommodate shifting of the sanitary napkin while it is being worn.
It is an object of this invention to provide an improved means for attaching the sanitary napkin to the undergarment of the wearer. It is also an object of this invention to provide a backsheet and flaps for the sanitary napkin which tolerate movement and mispositioning of the sanitary napkin relative to the wearer's undergarments and which provide a more comfortably fitting sanitary napkin.
BRIEF SUMMARY OF THE INVENTION
This invention comprises a sanitary napkin having a longitudinal axis, a lateral axis perpendicular to the longitudinal axis, and spaced apart longitudinal edges. The sanitary napkin has a liquid pervious topsheet, a liquid impervious backsheet, an absorbent core between the topsheet and the backsheet and at least one flap extending outwardly from the longitudinal edge of the sanitary napkin. At least one of the backsheet and the flap is elastically extensible in the direction parallel the lateral axis. The sanitary napkin preferably further comprises a means for attaching the sanitary napkin to the undergarment of the wearer, which attachment means is typically disposed on the outwardly oriented face of the backsheet or flap.
In a first embodiment, in one execution the flap is associated with either the topsheet, the backsheet, or both, at least a portion of which flap is elastically extensible in the lateral direction. In a second execution, the flap is associated with the longitudinal edge of the sanitary napkin along a longitudinally oriented pleat, and a laterally oriented spring spans the pleat so that the flap is elastically extensible in the lateral direction.
In a second embodiment the invention comprises a sanitary napkin having an elastically laterally extensible backsheet. This execution typically has attachment means in the form of two parallel, symmetrically opposite, or concave outwardly oriented adhesive strips, one of which is disposed on either side of the longitudinal centerline. This embodiment allows the strip of adhesive disposed on each side of the longitudinal centerline to move independently relative to the other strip of adhesive.
BRIEF DESCRIPTION OF THE DRAWINGS
While the Specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the invention will be better understood from the following description taken in conjunction with the accompanying drawings wherein like parts are given the same reference numeral, analogous parts are designated with a prime symbol and:
FIG. 1 is a top plan view of a sanitary napkin according to the present invention having two flaps in the laterally position;
FIG. 2 is a top plan view of the sanitary napkin of FIG. 1 having the flaps in the laterally extended position;
FIG. 3 is a bottom plan view, partially shown in cutaway, of a second execution of a sanitary napkin according to the present invention having the proximal end of the flap joined to the sanitary napkin by a Z-fold and a linear elastic spring spanning the Z-fold;
FIG. 4 is a vertical sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is a vertical sectional view of a third execution of a sanitary napkin according to the present invention having the proximal end of the flap joined to the sanitary napkin by an accordion fold and a spring inserted through the accordion fold;
FIG. 6 is a bottom plan view of a second embodiment of a sanitary napkin according to the present invention having two strips of adhesive in the retracted position; and
FIG. 7 is a bottom plan view of the sanitary napkin of FIG. 6, having the adhesive strips in the laterally extended position.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1-3, the invention comprises a disposable absorbent article, particularly a sanitary napkin 20. The sanitary napkin 20 is used to collect vaginal discharges, such as menses, and prevent soiling of the wearer's clothing by such discharges. The sanitary napkin 20 features a liquid pervious topsheet 22, a liquid impervious backsheet 24, an absorbent core 26 intermediate the topsheet 22 and the backsheet 24 and at least one flap 28 extending from a longitudinal edge 30 of the sanitary napkin 20, and preferably two symmetrically opposite flaps 28, one extending from each longitudinal edge 30 of the sanitary napkin 20. The perimeter of the sanitary napkin 20 is defined by the longitudinal edges 30 and two lateral edges 32.
Associated with each flap 28 is a means 40 for attaching the sanitary napkin 20 to the undergarment of a wearer. The means 40 for attaching the sanitary napkin 20 to the undergarment of a wearer is joined to a surface which is elastically laterally extensible. The elastically laterally extensible surface may, as illustrated in FIGS. 1 and 2, be a component of the sanitary napkin 20 having elastically extensible properties substantially throughout, or, as illustrated in FIGS. 3-5, have elastically extensible properties imparted by a discrete component, specifically added for such purpose. Preferably the lateral extension is accomplished by direct translation, so all longitudinally aligned points undergoing such lateral extension remain generally colinear and generally parallel to the longitudinal direction.
The sanitary napkin 20 has a generally centered longitudinal axis 34. As used herein the term "longitudinal" refers to an imaginary line, axis or direction of the sanitary napkin 20, which line, axis or direction is typically centered between the edges of the napkin and is generally aligned with the vertical plane which bisects a standing wearer into left and right body halves. The term "lateral" refers to an imaginary line, axis or direction generally orthogonal the longitudinal direction and within the plane of the sanitary napkin 20, and is generally sideways aligned relative to the wearer.
Examining the components in more detail with continuing reference to FIG. 3, the topsheet 22 is the component of the garment which is oriented towards and contacts the body of the wearer and receives bodily discharges. The topsheet 22 is liquid pervious and should be flexible and nonirritating to the skin. As used herein the term "flexible" refers to materials which are compliant and readily conform to the shape of the body or respond by easily deforming in the presence of external forces. Preferably the topsheet 22 is not noisy, to provide discretion for the wearer. The topsheet 22 should be clean in appearance and somewhat opaque to hide the bodily discharges collected in and absorbed by the core 26.
The topsheet 22 should further exhibit good strikethrough and rewet characteristics, permitting bodily discharges to rapidly penetrate the topsheet 22 to the core 26, but not flow back through the topsheet 22 to the skin of the wearer. Suitable topsheets may be made from nonwoven materials and perforated polyolefinic films. The topsheet 22 may, but need not, be elastically laterally extensible.
The topsheet 22 has a plurality of apertures to permit liquids deposited thereon to pass through to the core 26. Such apertures may, but need not, be present in the flaps 28. The topsheet 22 may be either laterally elastically extensible or elastically inextensible, as desired. If either an elastic or inelastic topsheet 22 is selected, an apertured polyolefinic film topsheet 22 having about 5 to about 60 percent open area, typically about 25 percent open area, and a thickness of about 0.01 to about 0.05 millimeters prior to aperturing and about 0.46 to about 0.51 millimeters after aperturing is suitable.
If desired, the topsheet 22 may be sprayed with a surfactant to enhance fluid penetration to the core 26. The surfactant is typically nonionic and should be nonirritating to the skin. A surfactant density of about 0.01 milligrams per square centimeter of topsheet 22 area is suitable. A suitable surfactant is sold by the Glyco Chemical, Inc. of Greenwich, Conn. as Pegosperse 200 ML.
A particularly suitable topsheet 22 may be made in accordance with U.S. Pat. No. 4,342,314 issued Aug. 3, 1982 to Radel et al. and U.S. Pat. No. 4,463,045 issued Jul. 31, 1984 to Ahr et al., which patents are incorporated herein by reference for the purpose of disclosing particularly preferred executions of liquid pervious topsheets. An elastically inextensible topsheet 22 made of model X-3265 or model P1552 apertured formed film sold by the Ethyl Corporation, Visqueen Division, of Terre Haute, Ind. has been found to work well. An elastically extensible formed film topsheet 22 may be made by aperturing film of the type described in U.S. Pat. No. 4,476,180, issued Oct. 9, 1984 to Wnuk, which patent is incorporated herein by reference for the purpose of showing a particularly preferred film. A suitable film of this type is sold by the Exxon Corporation of Houston, Tex. as EXX7.
The backsheet 24 may be any flexible, liquid impervious or liquid resistant material, such as a polyolefinic film, and prevents discharges collected by and contained in the sanitary napkin 20, particularly discharges absorbed by the core 26, from escaping the sanitary napkin 20 and soiling the clothing and bedding of the wearer. Preferably the backsheet 24 is not noisy, to provide discretion for the wearer.
The backsheet 24 may also be impervious to malodorous gases generated by absorbed bodily discharges, so that the malodors do not escape and become noticed by the wearer. If an inextensible backsheet 24 is selected, a low density polyethylene backsheet 24 about 0.01 to about 0.05 millimeters in thickness, preferably about 0.02 millimeters in thickness, has been found to work well. A polyethylene film, such as is sold by the Ethyl Corporation, Visqueen Division, under model XP-39385 has been found particularly well suited for this invention.
In a particularly preferred embodiment, the backsheet 24 is slightly larger than the topsheet 22 and intermediate absorbent core 26. In such an embodiment, the topsheet 22 and intermediate absorbent core 26 are peripherally circumscribed by the backsheet 24 which has a radial margin of about 0.5 centimeters to about 1.5 centimeters, preferably about 1.0 centimeter, from the edge of the topsheet 22. This geometry provides a marginal area of protection should the core 26 become overloaded or the sanitary napkin 20 otherwise fail. In such an embodiment the backsheet 24 and flaps 28 are preferably unitary and coextensive.
Further, the backsheet 24 may be made of a soft clothlike material which is hydrophobic relative to the topsheet 22, e.g., a polyester or polyolefinic fiber backsheet 24 works well. A particularly preferred soft, clothlike backsheet 24 material is a laminate of a polyester nonwoven material lamina and an uniaxially elastically extensible elastomeric film such as described in the aforementioned U.S. Pat. No. 4,476,180 issued to Wnuk. Preferably the nonwoven lamina is made of hydro-entangled fibers, so that the nonwoven lamina may be extended, without tearing or incurring undue distortion as the flap 28 is elastically extended in the lateral direction. Nonwoven, hydro-entangled fiber fabric having a basis weight of about 37 grams per square meter is suitable. A suitable nonwoven fabric may be purchased from the International Paper Company, Veratec Nonwovens Group, of Walpole, Mass., as zero strain fabric.
The elastically extensible film lamina may be made of ethylene vinyl acetate, rubber, polybutyl diene, or a Kraton based resin, sold by the Shell Oil Corporation of Houston, Tex. Preferably, the film should be easy to cast, thermoformable and have a high memory and propensity to return to the state when a tensile force applied to the film is released. A particularly well suited film is that described in the aforementioned U.S. Pat. No. 4,476,180 issued to Wnuk.
The laminae may be joined together to form a two laminae laminate. Alternatively, a three laminae laminate having a central lamina of the film and two substantially identical outboard laminae, each of the nonwoven material may be utilized. The laminae may be adhesively joined using longitudinally oriented beads about 0.8 millimeters wide spaced on a pitch of about 6 millimeters. Suitable adhesive is made by the Findley Adhesive Company of Wauwatosa, Wis. and sold under the tradename H2031.
The absorbent core 26 is the means for collecting and containing bodily discharges, particularly menses, deposited thereon or which otherwise traverses through the liquid permeable topsheet 22. The core 26 is the component of the sanitary napkin 20 which receives and retains the bodily discharges. The core 26 is conformable and nonirritating to the skin. The core 26 may be rectangular or hourglass shaped. The core 26 preferably has two opposed faces, one oriented towards the backsheet 24 and one oriented towards the topsheet 22.
Suitable core 26 materials include combinations of airfelt, such as cellulose wadding, and fibrated communition pulp; layers of tissue paper; and absorbent gelling materials. If a tissue paper core 26 is selected, tissue paper made in accordance with U.S. Pat. No. 4,191,609 issued Mar. 4, 1980 to Trokhan and incorporated herein by reference to show a particularly preferred tissue paper is suitable for the sanitary napkin 20 described herein. If it is desired to incorporate absorbent gelling materials into the core 26 of the sanitary napkin 20, absorbent gelling materials made in accordance with U.S. Pat. No. 4,654,039 issued Mar. 31, 1987 to Brandt et al. and incorporated herein by reference for showing particularly preferred absorbent gelling materials are suitable. A suitable laminate of absorbent gelling materials and tissue may be purchased from the Grain Processing Corporation of Muscatine, Iowa under Model Number L535.
The core 26 need not have a total absorbent capacity much greater than the total amount of bodily discharges to be absorbed. The core 26 is preferably narrow and thin, to be comfortable to the wearer. For the embodiment described herein the capacity of the core 26 should be at least about 2 grams of 0.9 percent saline solution. Suitable saline solution is sold by Travenol Laboratories of Deerfield, Ill.
The core 26 should be sized to register with the topsheet 22 and backsheet 24. The core 26 is preferably interposed between the topsheet 22 and backsheet 24 to prevent the absorbent material of the core 26 from shredding or becoming detached while the sanitary napkin 20 is worn and to ensure proper containment of bodily discharges. This arrangement also provides for a unitary assembly.
Further, the sanitary napkin 20 preferably has a caliper of less than about 4 millimeters and more preferably less than about 2 millimeters, as measured with a comparator gage having an approximately 80.0 gram test weight and an approximately 10.0 gram comparator foot having a diameter of about 2.54 centimeters and a contact surface area of approximately 5.1 square centimeters. Also, the sanitary napkin 20 of the present invention should have a topsheet 22 surface area of at least about 100 square centimeters to prevent discharged fluids from missing the target area.
The core 26 is preferentially joined to the topsheet 22, and may be joined to the backsheet 24. The term "joined" refers to the condition where a first member or component is affixed, or connected, to a second member or component either directly; or indirectly, where the first member or component is affixed, or connected, to an intermediate member or component which in turn is affixed, or connected, to the second member or component. The joined relationship between the first member, or component, and the second member, or component, is intended to remain for the life of the sanitary napkin 20.
Joining is preferentially accomplished by adhesive bonding the core 26 to the topsheet 22 or the backsheet 24. The adhesive may be applied in any suitable spray pattern, such as a spiral, or in longitudinally oriented beads. The adhesive should be surfactant resistant and of low pressure sensitivity, so as not to stick to the skin of the wearer.
The sanitary napkin 20 may also comprise a flap 28 extending from a longitudinal edge 30 of the sanitary napkin 20, and preferably one flap 28 extending from each longitudinal edge 30 of the sanitary napkin 20. The flap 28 extends away from the longitudinal axis 34 and central portion of the sanitary napkin 20. As used herein the phrase "central portion" refers to that part of the sanitary napkin 20 intermediate, particularly laterally intermediate, and defined by the proximal edges of the flaps 28.
The flap 28 may be comprised of an integral and contiguous extension of the topsheet 22, the backsheet 24, or a laminate of both. Alternatively, the flaps 28 may be made of a separate and independent piece of material joined to the longitudinal edge 30 of the sanitary napkin 20.
The flaps 28 have a proximal end 36 which is typically coincident with the juncture of attachment to the longitudinal edge 30 of the sanitary napkin 20 or, the proximal edge may be joined to the sanitary napkin 20 at another location juxtaposed with the longitudinal edge 30. The flaps 28 extend laterally outwardly from the sanitary napkin 20 and terminate at a distal edge which represents the point furthest from the longitudinal axis 34 of the sanitary napkin 20. The flaps 28 may be of any shape desired, with a particularly preferred shape being shown in FIG. 1.
The flaps 28 also have a means for attaching one surface of the flap 28 to the wearer's undergarment or to the other flap 28. The attachment means may be a mechanical fastener or, preferably, pressure sensitive adhesive 40. If pressure sensitive adhesive 40 is selected, it should be disposed on the face of the flap 28 which is oriented away from the topsheet 22 and core 26 when the flaps 28 are in the flat, extended and retracted positions of FIGS. 1 and 2--so that when the flaps 28 are wrapped around the crotch portion of the wearer's undergarment the adhesive 40 will face the outside of the wearer's undergarment. Suitable pressure sensitive adhesive 40 is sold by the Anchor Continental, Inc., 3 Sigma Division of Covington, Ohio as 0.02 millimeter pass with Century Adhesive A305-4. Preferably the adhesive 40 is covered by release paper (not shown) to prevent contamination and undesired attaching prior to use.
At least one flap 28 is elastically extensible in the lateral direction. As used herein the property "elastically extensible" is determined as follows. The sanitary napkin 20 or component of the sanitary napkin 20 is tested and considered elastically extensible if either of the following two test criteria are met, the first criterion being directed to testing of the component independently of the balance of the sanitary napkin 20, the second criterion being directed to testing the sanitary napkin 20 as an integral, unitary assembly.
For the first test, all release paper is removed from the sanitary napkin 20. Any exposed adhesive 40 may be blocked with a suitable agent, such as corn starch. The flap 28, backsheet 24, or other component of the sanitary napkin 20 to be tested, is severed from the rest of the sanitary napkin 20, for example, by cutting along the proximal edge of the flap 28 with scissors. Particularly desirable components of the sanitary napkin 20 to test are those surfaces to which means 40 to attach the sanitary napkin 20 to the undergarment of a wearer are joined. The portion of the component to be tested may be selected to specifically include known or suspected springs 44, if the springs 44 can be distinguished from inextensible portions of the sanitary napkin 20 components.
If the component to be tested has associated plural laminae, each lamina is independently tested by being separated from the other laminae. However, a lamina, or other foreign material, joined to the component to be tested is not removed, if such lamina or foreign material is joined to the component to be tested substantially throughout the test specimen. The component to be tested is then cut to a preferred test specimen size of about 6.4 centimeters (gage length) by about 2.54 centimeters (width). If the component to be tested is too small to yield the preferred test specimen size, a smaller specimen may be tested.
The elastic extensibility may be measured with a Model 1122 tensile machine made by the Instron Engineering Corporation of Canton, Mass. Preferred jaws for this tensile machine are pneumatic action, coated, light duty, flat faced jaws Instron model number 3B. The sample to be tested is mounted in the tensile machine with the principal axis of elongation oriented in the tensile machine extension direction. The component of the sanitary napkin 20 to be tested is preferably inserted into each jaw of the tensile machine only a distance sufficient to prevent tearing out of the jaws upon the application of the tensile force.
The jaws are separated, without tensile loading the sample, until it is taut. All wrinkles, except designed pleats 42, folds 42 and the like, should be removed. This defines the original jaw position of the sample.
The jaws are separated at a constant rate of about 100 centimeters per minute until an elongation of about 25 percent (1.25 times the original gage length) is reached. This procedure produces an extension stress-strain curve from the original gage length and jaw position to the extended position, and having the stress vector along the vertical axis and the strain vector along the horizontal axis. The area under this curve is calculated and hereinafter referred to as A 1 . A suitable means for calculating the area under this curve is with a computer program such as is sold by Laboratory MicroSystems, Inc. of Troy, N.Y. under the name Mechanical Test Package.
The jaws are then returned to the original jaw position at a constant rate of about 100 centimeters per minute. This defines a relaxation stress-strain curve, from the extended position to the original gage length. The area under this stress-strain curve is also calculated and is hereinafter referred to as A 2 .
The ratio of the area of the relaxation stress-strain curve to the area of the extension stress-strain curve, A 2 /A 1 , is then found and is hereinafter referred to as the relaxation-extension area ratio. Under the first criterion the tested component of the sanitary napkin 20 is considered elastically extensible if the relaxation-extension area ratio is greater than or equal to about 0.6. More preferably, the tested component exhibits a relaxation-extension area ratio greater than or equal to about 0.75. The tested component is considered to be elastically laterally extensible and within the intent and scope of the claimed invention if such component is mounted in the sanitary napkin 20 so that an axis of elastic extensibility has at least a 10° vector component in the lateral direction.
If the relaxation extension area ratio is less than about 0.6, such as would likely and typically occur when the tested component of the sanitary napkin 20 rips, shreds, or undergoes unintended, excessive gross or plastic deformation, such a component of the sanitary napkin 20 is outside the intent and scope of the claimed invention.
The second criterion for determining elastic extensibility utilizes the entire sanitary napkin 20, minus any release paper, as a unitary assembly. If desired, any exposed adhesive 40 may be blocked as described above.
The sanitary napkin 20 to be tested is then mounted in the jaws of a tensile machine, as described above. If the sanitary napkin 20 has one flap 28 extending from each longitudinal edge 30, each flap 28 is mounted in a jaw of the tensile machine approximately the minimum distance necessary to preclude the flap 28 from pulling out of the jaw during the test procedure. If the sanitary napkin 20 has no flaps 28 extending from the longitudinal edges 30, each longitudinal edge 30 is inserted into a jaw of the tensile machine. If the sanitary napkin 20 has one flap 28 extending from a longitudinal edge 30, this flap 28 and the opposite longitudinal edge 30 are inserted into the jaws of the tensile machine. A gage length of about 12.7 centimeters is generally preferred, but not required, for all of the aforementioned combinations.
The sanitary napkin 20 should be mounted with the lateral direction oriented parallel the extension direction of the tensile machine. The original jaw position is found as described above. Alternative tests may be conducted with at least a 10° lateral vector component of the sanitary napkin 20 aligned with the extension direction of the tensile machine.
The sanitary napkin 20 is then tested, by separating the jaws at a constant rate of about 100 centimeters per minute, until an elongation of about 15 percent (1.15 times the original sample length) is reached, recording the tensile load at this extension, and returning the jaws to the original jaw positions. This procedure is repeated, so that the sanitary napkin 20 has been cycled twice.
Under the second criterion, the tested sanitary napkin 20 is considered elastically extensible and falls within the intent and scope of the claimed invention if the resultant tensile load at about 15 percent extension for either cycle is less than or equal to about 900 grams and the tested sanitary napkin 20 returns to within about 5 percent of the original sample length, i.e. does not have a permanent set greater than about 5 percent. More preferably such a sanitary napkin 20 exhibits a resultant tensile load at 15 extension of less than about 750 grams and most preferably less than about 500 grams. However, a resultant tensile load of about 25 grams, to impart lateral stability to the sanitary napkin 20, is desirable.
Materials which are elastically extensible may be elastomeric, or have the elastic properties imparted through a knitted or woven configuration. The flap 28 may be elastically laterally extensible in its entirety or, alternatively, only a portion of the flap 28 may be elastically laterally extensible. Any configuration in which the distal end 38 of the flap 28 may be elastically laterally extended from the neutral, retracted position at least about 0.5 centimeter is suitable and within the scope of the claimed invention.
Referring to FIG. 2, the flaps 28 may preferably be elastically laterally extended from the neutral, retracted position between about 0.5 centimeters and about 5.0 centimeters. The flap 28 should reach approximately 25 percent extension under a tensile force of not more than about 900 grams, preferably not more than about 750 grams and most preferably not more than about 500 grams. However a resultant tensile force of at least about 25 grams is desirable. This arrangement provides a structure which has a degree of lateral stability and prevents unintended lateral displacement of the sanitary napkin 20 components.
If desired, one of either the backsheet 24 or flaps 28 may be made of a soft clothlike material and the other made of a different material, which materials are joined along the proximal edge of the flap 28. Preferably, for ease of manufacture, both the backsheet 24 and flaps 28 are made of elastically laterally extensible material. However, either the flaps 28 may be elastically laterally extensible or the backsheet 24 may be made elastically laterally extensible and the flaps 28 relatively or totally laterally inextensible, provided, however, that the lateral extension of the backsheet 24 must not be constrained by the joining of either the backsheet 24 or flap 28 to either the core 26 or topsheet 22.
It wi 11 be apparent to one ski 11 ed i n the art that an embodiment closely related to that illustrated in FIG. 2 has the flaps 28 and the topsheet 22 integral and coextensive. The topsheet 22 may be made of any elastically extensible material, such as an elastically extensible formed film, or a nonwoven material.
Alternatively in another execution (not shown), the topsheet 22 and backsheet 24 may be generally coextensive, elastically laterally extensible, and joined together to provide a laminated flap 28 having two laminae. If an execution of the embodiment shown in FIGS. 1 and 2 is selected, the topsheet 22 and backsheet 24 should have generally similar elastic properties, otherwise the lamina having the greater spring constant and lesser total extension will control the laminated flap 28.
Referring back to FIG. 3, in a second embodiment, the flaps 28 may be made laterally extensible by providing longitudinally oriented pleats 42 juxtaposed with or, preferably, at the juncture of the proximal edge of the flap 28 and the central portion of the sanitary napkin 20. The longitudinally oriented pleat 42 allows the flap 28 to be laterally extended from the retracted position to a fully extended position.
A laterally oriented return spring 44 is provided and spans the longitudinally oriented pleat 42 to make the flap 28 elastically laterally extensible. The spring 44 may operate at a diagonal relative to the lateral direction, but it is preferred the principal orientation of the spring 44 be laterally aligned. Suitable springs 44 include linearly shaped elastic strands. If a linear elastic strand is selected for the spring 44, the strand may be adhesively joined at each end to the outwardly oriented face of the backsheet 24, one end being joined to the central portion of the sanitary napkin 20 and the other end being joined to the flap 28, as illustrated in FIG. 4. Also, as illustrated, the laterally extensible flap 28 may be made from the topsheet 22. Adhesive joining of the spring 44 is preferentially accomplished using model number H2031 adhesive, made by the Findley Adhesives Company of Wauwatosa, Wis
Referring to FIG. 5, the pleat 42' may comprise at least one accordion fold 42', forming a connection which joins the central portion of the backsheet 24 to the outwardly extending flap 28. The accordion fold 42' provides a means for increasing the lateral extension of the flap 28. The spring 44' spans the accordion fold 42' by being inserted through and joined to one or more of the folds, rather than being joined across the outwardly oriented face of the backsheet 24, so that the spring 44' biases the flap 28 to return to a neutral, retracted position.
Alternatively, the linear elastic strand may be prestretched prior to being joined, substantially throughout the entire length of the spring 44, to the outwardly oriented face of the backsheet 24. Such a configuration causes the elastic to contract to its retracted position and results in rugosities in the backsheet 24. If desired, in such an embodiment the prestretched elastic springs 44 may be applied to the inwardly oriented face of the backsheet 24 or the inwardly oriented face of the topsheet 22, so long as the springs 44 extend from the central portion of the sanitary napkin 20 into the flaps 28. It is preferred that the springs 44 not be placed on the outwardly oriented face of the topsheet 22, so that the springs 44 avoid contact with the skin of the wearer.
In yet another embodiment, the spring 44 may span the pleat 42 having one end joined to each of the pleats 42, in lieu of being joined to the backsheet 24. In this arrangement the biasing force of each spring 44 acts directly on the opposite spring 44 to return both flaps 28 to the retracted position.
Referring to FIG. 6, illustrated is a sanitary napkin 20 according to the present invention and otherwise as described above, except the sanitary napkin 20 does not having a laterally extending flap 28 joined to the longitudinal edge 30 of the sanitary napkin 20. Such an embodiment has at least one means, preferably pressure sensitive adhesive 40', for attaching the sanitary napkin 20 to the undergarment of the wearer disposed on each side of the longitudinal centerline. As illustrated in FIG. 7, such a sanitary napkin 20 further has a means for elastically extending the pressure sensitive adhesive 40', or other means for joining the sanitary napkin 20 to the undergarment, in the lateral direction. Particularly, such an embodiment has a laterally extensible backsheet 24 made of the aforementioned film material described in U.S. Pat. No. 4,476,180 issued to Wnuk.
A preferred means for attaching such a sanitary napkin 20 to the undergarment of the wearer comprises two strips of pressure sensitive adhesive 40', each having its longitudinal centerline laterally offset about 1 to about 2 centimeters from the longitudinal axis 34 of the sanitary napkin 20. As used herein the phrase "longitudinal centerline of the adhesive" refers to the line generally centered within the strip of adhesive 40' and equidistant from each longitudinal edge 30 of the adhesive strip. The adhesive strips are preferably about 10 to about 15 millimeters in lateral width. As noted, the adhesive strips 40' may be continuous, intermittent, and applied in any pattern judged desirable by one skilled in the art.
A particular preferred means of making the pressure sensitive adhesive 40', or other means for attaching the sanitary napkin 20 to the undergarment of the wearer, elastically extensible in the lateral direction is to provide a backsheet 24, to which the attaching means is joined, which is elastically extensible in the lateral direction. As noted above, a particularly preferred sanitary napkin 20, and particularly the backsheet 24, has at 15 percent extension a resultant tensile load of not more than about 900 grams, more preferably not more than about 750 grams and most preferably not more than about 500 grams. As noted above, however, a resultant lateral force of at least about 25 grams is preferred, and allows the centerline of the adhesive 40' to be elastically laterally extended at least about 0.5 centimeter according to the aforementioned parameters.
The backsheet 24 may be made elastically laterally extensible by providing a backsheet 24 which is itself elastic, and either made of an elastomeric material or, achieves the elastic properties of resilience and recovery through a knitted or woven configuration. Alternatively, the backsheet 24 may be made of a relatively inelastic material, but have elastic properties imparted through an elastic spring 44 as described above.
It will be apparent to one skilled in the art that several variations of the above described embodiments are feasible. For example, the backsheet 24 or flaps 28 may be made of material which is biaxially elastic and provide for extension in both the longitudinal and lateral direction. Also, a backsheet 24 or flaps 28 which have a diagonal component of elastic extensibility relative to the longitudinal and lateral directions are feasible. Any orientation which provides for a vector component of elastic extension in the lateral direction is suitable; however, as noted above, an orientation which is substantially coincident with the lateral direction is generally preferred.
The embodiments described above may be combined to yield a backsheet 24 having a longitudinally oriented pleat 42, a Z-fold or accordion fold 42 and a return spring 44 spanning such pleat 42 or fold. All such variations are within the spirit and scope of the claimed invention.
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An improved sanitary napkin is disclosed. The sanitary napkin has a laterally extensible flap which extends outwardly from one of the longitudinal edges of the sanitary napkin or a laterally extensible backsheet. The backsheet or flap may be laterally extended from the neutral, retracted position and will return to the retracted position upon release of the disturbing force. This arrangement provides the advantage that any adhesive strips or patches associated with the flaps or backsheet more easily move with the undergarment of the wearer and are less likely to be stressed or become detached from the undergarment of the wearer due to the forces encountered during typical wearer movements.
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